diff --git a/.coin-or/projDesc.xml b/.coin-or/projDesc.xml
index 1ee247e100f..d13ac8804cf 100644
--- a/.coin-or/projDesc.xml
+++ b/.coin-or/projDesc.xml
@@ -227,8 +227,8 @@ Carl D. Laird, Chair, Pyomo Management Committee, claird at andrew dot cmu dot e
 			     Use explicit overrides to disable use of automated
 			     version reporting.
 			-->
-			<stableVersionNumber>6.7.0</stableVersionNumber>
-			<releaseNumber>6.7.0</releaseNumber>
+			<stableVersionNumber>6.7.3</stableVersionNumber>
+			<releaseNumber>6.7.3</releaseNumber>
 
 		</developmentStatus>
 
diff --git a/.github/workflows/release_wheel_creation.yml b/.github/workflows/release_wheel_creation.yml
index ef44806d6d4..932b0d8eea6 100644
--- a/.github/workflows/release_wheel_creation.yml
+++ b/.github/workflows/release_wheel_creation.yml
@@ -22,14 +22,27 @@ jobs:
     name: Build wheels (${{ matrix.wheel-version }}) on ${{ matrix.os }} for native and cross-compiled architecture
     runs-on: ${{ matrix.os }}
     strategy:
+      fail-fast: true
       matrix:
         os: [ubuntu-22.04, windows-latest, macos-latest]
         arch: [all]
         wheel-version: ['cp38*', 'cp39*', 'cp310*', 'cp311*', 'cp312*']
+
+        include:
+        - wheel-version: 'cp38*'
+          TARGET: 'py38'
+        - wheel-version: 'cp39*'
+          TARGET: 'py39'
+        - wheel-version: 'cp310*'
+          TARGET: 'py310'
+        - wheel-version: 'cp311*'
+          TARGET: 'py311'
+        - wheel-version: 'cp312*'
+          TARGET: 'py312'
     steps:
       - uses: actions/checkout@v4
       - name: Build wheels
-        uses: pypa/cibuildwheel@v2.16.2
+        uses: pypa/cibuildwheel@v2.16.5
         with:
           output-dir: dist
         env:
@@ -43,8 +56,9 @@ jobs:
             CIBW_CONFIG_SETTINGS: '--global-option="--with-cython --with-distributable-extensions"'
       - uses: actions/upload-artifact@v4
         with:
-          name: native_wheels
+          name: native_wheels-${{ matrix.os }}-${{ matrix.TARGET }}
           path: dist/*.whl
+          overwrite: true
 
   alternative_wheels:
     name: Build wheels (${{ matrix.wheel-version }}) on ${{ matrix.os }} for aarch64
@@ -54,6 +68,18 @@ jobs:
         os: [ubuntu-22.04]
         arch: [all]
         wheel-version: ['cp38*', 'cp39*', 'cp310*', 'cp311*', 'cp312*']
+
+        include:
+        - wheel-version: 'cp38*'
+          TARGET: 'py38'
+        - wheel-version: 'cp39*'
+          TARGET: 'py39'
+        - wheel-version: 'cp310*'
+          TARGET: 'py310'
+        - wheel-version: 'cp311*'
+          TARGET: 'py311'
+        - wheel-version: 'cp312*'
+          TARGET: 'py312'
     steps:
       - uses: actions/checkout@v4
       - name: Set up QEMU
@@ -62,7 +88,7 @@ jobs:
         with:
           platforms: all
       - name: Build wheels
-        uses: pypa/cibuildwheel@v2.16.2
+        uses: pypa/cibuildwheel@v2.16.5
         with:
           output-dir: dist
         env:
@@ -74,8 +100,9 @@ jobs:
             CIBW_CONFIG_SETTINGS: '--global-option="--with-cython --with-distributable-extensions"'
       - uses: actions/upload-artifact@v4
         with:
-          name: alt_wheels
+          name: alt_wheels-${{ matrix.os }}-${{ matrix.TARGET }}
           path: dist/*.whl
+          overwrite: true
 
   generictarball:
     name: ${{ matrix.TARGET }}
@@ -106,4 +133,5 @@ jobs:
       with:
         name: generictarball
         path: dist
+        overwrite: true
 
diff --git a/.github/workflows/test_branches.yml b/.github/workflows/test_branches.yml
index e5513d25975..03894a1cb20 100644
--- a/.github/workflows/test_branches.yml
+++ b/.github/workflows/test_branches.yml
@@ -40,12 +40,27 @@ jobs:
         python-version: '3.10'
     - name: Black Formatting Check
       run: |
-        pip install black
+        # Note v24.4.1 fails due to a bug in the parser
+        pip install 'black!=24.4.1'
         black . -S -C --check --diff --exclude examples/pyomobook/python-ch/BadIndent.py
     - name: Spell Check
       uses: crate-ci/typos@master
       with: 
         config: ./.github/workflows/typos.toml
+    - name: URL Checker
+      uses: urlstechie/urlchecker-action@0.0.34
+      with:
+        # A comma-separated list of file types to cover in the URL checks
+        file_types: .md,.rst,.py
+        # Choose whether to include file with no URLs in the prints.
+        print_all: false
+        # More verbose summary at the end of a run
+        verbose: true
+        # How many times to retry a failed request (defaults to 1)
+        retry_count: 3
+        # Exclude Jenkins because it's behind a firewall; ignore RTD because
+        # a magically-generated string is triggering a failure
+        exclude_urls: https://pyomo-jenkins.sandia.gov/,https://pyomo.readthedocs.io/en/%s/errors.html
 
 
   build:
@@ -66,7 +81,7 @@ jobs:
           TARGET: linux
           PYENV: pip
 
-        - os: macos-latest
+        - os: macos-13
           python: '3.10'
           TARGET: osx
           PYENV: pip
@@ -75,7 +90,7 @@ jobs:
           python: 3.9
           TARGET: win
           PYENV: conda
-          PACKAGES: glpk pytest-qt
+          PACKAGES: glpk pytest-qt filelock
 
         - os: ubuntu-latest
           python: '3.11'
@@ -86,13 +101,13 @@ jobs:
           PACKAGES: pytest-qt
 
         - os: ubuntu-latest
-          python: 3.9
+          python: '3.10'
           other: /mpi
           mpi: 3
           skip_doctest: 1
           TARGET: linux
           PYENV: conda
-          PACKAGES: mpi4py
+          PACKAGES: openmpi mpi4py
 
         - os: ubuntu-latest
           python: '3.10'
@@ -180,7 +195,7 @@ jobs:
         # Notes:
         #  - install glpk
         #  - pyodbc needs: gcc pkg-config unixodbc freetds
-        for pkg in bash pkg-config unixodbc freetds glpk; do
+        for pkg in bash pkg-config unixodbc freetds glpk ginac; do
             brew list $pkg || brew install $pkg
         done
 
@@ -192,7 +207,8 @@ jobs:
         #  - install glpk
         #  - ipopt needs: libopenblas-dev gfortran liblapack-dev
         sudo apt-get -o Dir::Cache=${GITHUB_WORKSPACE}/cache/os \
-            install libopenblas-dev gfortran liblapack-dev glpk-utils
+            install libopenblas-dev gfortran liblapack-dev glpk-utils \
+            libginac-dev
         sudo chmod -R 777 ${GITHUB_WORKSPACE}/cache/os
 
     - name: Update Windows
@@ -263,11 +279,12 @@ jobs:
         if test -z "${{matrix.slim}}"; then
             python -m pip install --cache-dir cache/pip cplex docplex \
                 || echo "WARNING: CPLEX Community Edition is not available"
-            python -m pip install --cache-dir cache/pip \
-                -i https://pypi.gurobi.com gurobipy==10.0.3 \
+            python -m pip install --cache-dir cache/pip gurobipy==10.0.3 \
                 || echo "WARNING: Gurobi is not available"
             python -m pip install --cache-dir cache/pip xpress \
                 || echo "WARNING: Xpress Community Edition is not available"
+            python -m pip install --cache-dir cache/pip maingopy \
+                || echo "WARNING: MAiNGO is not available"
             if [[ ${{matrix.python}} == pypy* ]]; then
                 echo "skipping wntr for pypy"
             else
@@ -333,6 +350,7 @@ jobs:
                 CONDA_DEPENDENCIES="$CONDA_DEPENDENCIES $PKG"
             fi
         done
+        echo ""
         echo "*** Install Pyomo dependencies ***"
         # Note: this will fail the build if any installation fails (or
         # possibly if it outputs messages to stderr)
@@ -501,7 +519,7 @@ jobs:
         $BARON_DIR = "${env:TPL_DIR}/baron"
         echo "$BARON_DIR" | `
             Out-File -FilePath $env:GITHUB_PATH -Encoding utf8 -Append
-        $URL = "https://www.minlp.com/downloads/xecs/baron/current/"
+        $URL = "https://minlp.com/downloads/xecs/baron/current/"
         if ( "${{matrix.TARGET}}" -eq "win" ) {
             $INSTALLER = "${env:DOWNLOAD_DIR}/baron_install.exe"
             $URL += "baron-win64.exe"
@@ -631,7 +649,7 @@ jobs:
         $PYTHON_EXE -c "from pyomo.dataportal.parse_datacmds import \
             parse_data_commands; parse_data_commands(data='')"
         # Note: if we are testing with openmpi, add '--oversubscribe'
-        mpirun -np ${{matrix.mpi}} pytest -v \
+        mpirun -np ${{matrix.mpi}} -oversubscribe pytest -v \
             --junit-xml=TEST-pyomo-mpi.xml \
             -m "mpi" -W ignore::Warning \
             pyomo `pwd`/pyomo-model-libraries
@@ -708,12 +726,12 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest, macos-latest, windows-latest]
+        os: [ubuntu-latest, macos-13, windows-latest]
 
         include:
         - os: ubuntu-latest
           TARGET: linux
-        - os: macos-latest
+        - os: macos-13
           TARGET: osx
         - os: windows-latest
           TARGET: win
diff --git a/.github/workflows/test_pr_and_main.yml b/.github/workflows/test_pr_and_main.yml
index c5028606c17..cc9760cbe5d 100644
--- a/.github/workflows/test_pr_and_main.yml
+++ b/.github/workflows/test_pr_and_main.yml
@@ -7,6 +7,11 @@ on:
   pull_request:
     branches:
       - main
+    types:
+      - opened
+      - reopened
+      - synchronize
+      - ready_for_review
   workflow_dispatch:
     inputs:
       git-ref:
@@ -34,6 +39,8 @@ jobs:
   lint:
     name: lint/style-and-typos
     runs-on: ubuntu-latest
+    if: |
+      contains(github.event.pull_request.title, '[WIP]') != true && !github.event.pull_request.draft
     steps:
     - name: Checkout Pyomo source
       uses: actions/checkout@v4
@@ -43,12 +50,28 @@ jobs:
         python-version: '3.10'
     - name: Black Formatting Check
       run: |
-        pip install black
+        # Note v24.4.1 fails due to a bug in the parser
+        pip install 'black!=24.4.1'
         black . -S -C --check --diff --exclude examples/pyomobook/python-ch/BadIndent.py
     - name: Spell Check
       uses: crate-ci/typos@master
       with: 
         config: ./.github/workflows/typos.toml
+    - name: URL Checker
+      uses: urlstechie/urlchecker-action@0.0.34
+      with:
+        # A comma-separated list of file types to cover in the URL checks
+        file_types: .md,.rst,.py
+        # Choose whether to include file with no URLs in the prints.
+        print_all: false
+        # More verbose summary at the end of a run
+        verbose: true
+        # How many times to retry a failed request (defaults to 1)
+        retry_count: 3
+        # Exclude:
+        #  - Jenkins because it's behind a firewall
+        #  - RTD because a magically-generated string triggers failures
+        exclude_urls: https://pyomo-jenkins.sandia.gov/,https://pyomo.readthedocs.io/en/%s/errors.html
 
 
   build:
@@ -59,24 +82,29 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest, macos-latest, windows-latest]
+        os: [ubuntu-latest, macos-13, windows-latest]
         python: [ 3.8, 3.9, '3.10', '3.11', '3.12' ]
         other: [""]
         category: [""]
 
+        # win/3.8 conda builds no longer work due to environment not being able
+        # to resolve. We are skipping it now.
+        exclude:
+        - os: windows-latest
+          python: 3.8
         include:
         - os: ubuntu-latest
           TARGET: linux
           PYENV: pip
 
-        - os: macos-latest
+        - os: macos-13
           TARGET: osx
           PYENV: pip
 
         - os: windows-latest
           TARGET: win
           PYENV: conda
-          PACKAGES: glpk pytest-qt
+          PACKAGES: glpk pytest-qt filelock
 
         - os: ubuntu-latest
           python: '3.11'
@@ -87,13 +115,13 @@ jobs:
           PACKAGES: pytest-qt
 
         - os: ubuntu-latest
-          python: 3.9
+          python: '3.10'
           other: /mpi
           mpi: 3
           skip_doctest: 1
           TARGET: linux
           PYENV: conda
-          PACKAGES: mpi4py
+          PACKAGES: openmpi mpi4py
 
         - os: ubuntu-latest
           python: '3.11'
@@ -210,7 +238,7 @@ jobs:
         # Notes:
         #  - install glpk
         #  - pyodbc needs: gcc pkg-config unixodbc freetds
-        for pkg in bash pkg-config unixodbc freetds glpk; do
+        for pkg in bash pkg-config unixodbc freetds glpk ginac; do
             brew list $pkg || brew install $pkg
         done
 
@@ -222,7 +250,8 @@ jobs:
         #  - install glpk
         #  - ipopt needs: libopenblas-dev gfortran liblapack-dev
         sudo apt-get -o Dir::Cache=${GITHUB_WORKSPACE}/cache/os \
-            install libopenblas-dev gfortran liblapack-dev glpk-utils
+            install libopenblas-dev gfortran liblapack-dev glpk-utils \
+            libginac-dev
         sudo chmod -R 777 ${GITHUB_WORKSPACE}/cache/os
 
     - name: Update Windows
@@ -293,11 +322,12 @@ jobs:
         if test -z "${{matrix.slim}}"; then
             python -m pip install --cache-dir cache/pip cplex docplex \
                 || echo "WARNING: CPLEX Community Edition is not available"
-            python -m pip install --cache-dir cache/pip \
-                -i https://pypi.gurobi.com gurobipy==10.0.3 \
+            python -m pip install --cache-dir cache/pip gurobipy==10.0.3 \
                 || echo "WARNING: Gurobi is not available"
             python -m pip install --cache-dir cache/pip xpress \
                 || echo "WARNING: Xpress Community Edition is not available"
+            python -m pip install --cache-dir cache/pip maingopy \
+                || echo "WARNING: MAiNGO is not available"
             if [[ ${{matrix.python}} == pypy* ]]; then
                 echo "skipping wntr for pypy"
             else
@@ -363,6 +393,7 @@ jobs:
                 CONDA_DEPENDENCIES="$CONDA_DEPENDENCIES $PKG"
             fi
         done
+        echo ""
         echo "*** Install Pyomo dependencies ***"
         # Note: this will fail the build if any installation fails (or
         # possibly if it outputs messages to stderr)
@@ -531,7 +562,7 @@ jobs:
         $BARON_DIR = "${env:TPL_DIR}/baron"
         echo "$BARON_DIR" | `
             Out-File -FilePath $env:GITHUB_PATH -Encoding utf8 -Append
-        $URL = "https://www.minlp.com/downloads/xecs/baron/current/"
+        $URL = "https://minlp.com/downloads/xecs/baron/current/"
         if ( "${{matrix.TARGET}}" -eq "win" ) {
             $INSTALLER = "${env:DOWNLOAD_DIR}/baron_install.exe"
             $URL += "baron-win64.exe"
@@ -605,7 +636,8 @@ jobs:
       if: ${{ ! matrix.slim }}
       shell: bash
       run: |
-        $PYTHON_EXE -m pip install --cache-dir cache/pip highspy \
+        echo "NOTE: temporarily pinning to highspy pre-release for testing"
+        $PYTHON_EXE -m pip install --cache-dir cache/pip "highspy>=1.7.1.dev1" \
             || echo "WARNING: highspy is not available"
 
     - name: Set up coverage tracking
@@ -661,7 +693,7 @@ jobs:
         $PYTHON_EXE -c "from pyomo.dataportal.parse_datacmds import \
             parse_data_commands; parse_data_commands(data='')"
         # Note: if we are testing with openmpi, add '--oversubscribe'
-        mpirun -np ${{matrix.mpi}} pytest -v \
+        mpirun -np ${{matrix.mpi}} -oversubscribe pytest -v \
             --junit-xml=TEST-pyomo-mpi.xml \
             -m "mpi" -W ignore::Warning \
             pyomo `pwd`/pyomo-model-libraries
@@ -733,18 +765,18 @@ jobs:
   cover:
     name: process-coverage-${{ matrix.TARGET }}
     needs: build
-    if: always() # run even if a build job fails
+    if: success() || failure() # run even if a build job fails, but not if cancelled
     runs-on: ${{ matrix.os }}
     timeout-minutes: 10
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest, macos-latest, windows-latest]
+        os: [ubuntu-latest, macos-13, windows-latest]
 
         include:
         - os: ubuntu-latest
           TARGET: linux
-        - os: macos-latest
+        - os: macos-13
           TARGET: osx
         - os: windows-latest
           TARGET: win
diff --git a/.github/workflows/typos.toml b/.github/workflows/typos.toml
index 23f94fc8afd..80d50477ca4 100644
--- a/.github/workflows/typos.toml
+++ b/.github/workflows/typos.toml
@@ -38,6 +38,37 @@ caf = "caf"
 WRONLY = "WRONLY"
 # Ignore the name Hax
 Hax = "Hax"
+# Ignore dout (short for dual output in SAS solvers)
+dout = "dout"
 # Big Sur
 Sur = "Sur"
+# contrib package named mis and the acronym whence the name comes
+mis = "mis"
+MIS = "MIS"
+# Ignore the shorthand ans for answer
+ans = "ans"
+# Ignore the keyword arange
+arange = "arange"
+# Ignore IIS
+IIS = "IIS"
+iis = "iis"
+# Ignore PN
+PN = "PN"
+# Ignore hd
+hd = "hd"
+# Ignore opf
+opf = "opf"
+# Ignore FRE
+FRE = "FRE"
+# Ignore MCH
+MCH = "MCH"
+# Ignore RO
+ro = "ro"
+RO = "RO"
+# Ignore EOF - end of file
+EOF = "EOF"
+# Ignore lst as shorthand for list
+lst = "lst"
+# Abbreviation of gamma (used in stochpdegas1_automatic.py)
+gam = "gam"
 # AS NEEDED: Add More Words Below
diff --git a/.jenkins.sh b/.jenkins.sh
index 37be6113ed9..8771427805d 100644
--- a/.jenkins.sh
+++ b/.jenkins.sh
@@ -20,8 +20,11 @@
 #
 # CODECOV_TOKEN: the token to use when uploading results to codecov.io
 #
-# CODECOV_ARGS: additional arguments to pass to the codecov uploader
-#     (e.g., to support SSL certificates)
+# CODECOV_SOURCE_BRANCH: passed to the 'codecov-cli' command; branch of Pyomo
+#     (e.g., to enable correct codecov uploads)
+#
+# CODECOV_REPO_OWNER: passed to the 'codecov-cli' command; owner of repo
+#     (e.g., to enable correct codecov uploads)
 #
 # DISABLE_COVERAGE: if nonempty, then coverage analysis is disabled
 #
@@ -43,9 +46,6 @@ fi
 if test -z "$SLIM"; then
     export VENV_SYSTEM_PACKAGES='--system-site-packages'
 fi
-if test ! -z "$CATEGORY"; then
-    export PY_CAT="-m $CATEGORY"
-fi
 
 if test "$WORKSPACE" != "`pwd`"; then
     echo "ERROR: pwd is not WORKSPACE"
@@ -122,10 +122,23 @@ if test -z "$MODE" -o "$MODE" == setup; then
     echo "PYOMO_CONFIG_DIR=$PYOMO_CONFIG_DIR"
     echo ""
 
+    # Call Pyomo build scripts to build TPLs that would normally be
+    # skipped by the pyomo download-extensions / build-extensions
+    # actions below
+    if [[ " $CATEGORY " == *" builders "* ]]; then
+        echo ""
+        echo "Running local build scripts..."
+        echo ""
+        set -x
+        python pyomo/contrib/simplification/build.py --build-deps || exit 1
+        set +x
+    fi
+
     # Use Pyomo to download & compile binary extensions
     i=0
     while /bin/true; do
         i=$[$i+1]
+        echo ""
         echo "Downloading pyomo extensions (attempt $i)"
         pyomo download-extensions $PYOMO_DOWNLOAD_ARGS
         if test $? == 0; then
@@ -178,7 +191,7 @@ if test -z "$MODE" -o "$MODE" == test; then
     python -m pytest -v \
         -W ignore::Warning \
         --junitxml="TEST-pyomo.xml" \
-        $PY_CAT $TEST_SUITES $PYTEST_EXTRA_ARGS
+        -m "$CATEGORY" $TEST_SUITES $PYTEST_EXTRA_ARGS
 
     # Combine the coverage results and upload
     if test -z "$DISABLE_COVERAGE"; then
@@ -192,22 +205,43 @@ if test -z "$MODE" -o "$MODE" == test; then
         # Note, that the PWD should still be $WORKSPACE/pyomo
         #
         coverage combine || exit 1
-        coverage report -i
+        coverage report -i || exit 1
+        coverage xml -i || exit 1
         export OS=`uname`
-        if test -z "$CODECOV_TOKEN"; then
-            coverage xml
-        else
-            CODECOV_JOB_NAME=`echo ${JOB_NAME} | sed -r 's/^(.*autotest_)?Pyomo_([^\/]+).*/\2/'`.$BUILD_NUMBER.$python
+        if test -z "$PYOMO_SOURCE_SHA"; then
+            PYOMO_SOURCE_SHA=$GIT_COMMIT
+        fi
+        if test -n "$CODECOV_TOKEN" -a -n "$PYOMO_SOURCE_SHA"; then
+            CODECOV_JOB_NAME=$(echo ${JOB_NAME} \
+                | sed -r 's/^(.*autotest_)?Pyomo_([^\/]+).*/\2/').$BUILD_NUMBER.$python
+            if test -z "$CODECOV_REPO_OWNER"; then
+                if test -n "$PYOMO_SOURCE_REPO"; then
+                    CODECOV_REPO_OWNER=$(echo "$PYOMO_SOURCE_REPO" | cut -d '/' -f 4)
+                elif test -n "$GIT_URL"; then
+                    CODECOV_REPO_OWNER=$(echo "$GIT_URL" | cut -d '/' -f 4)
+                else
+                    CODECOV_REPO_OWNER=""
+                fi
+            fi
+            if test -z "$CODECOV_SOURCE_BRANCH"; then
+                CODECOV_SOURCE_BRANCH=$(git branch -av --contains "$PYOMO_SOURCE_SHA" \
+                    | grep "${PYOMO_SOURCE_SHA:0:7}" | grep "/origin/" \
+                    | cut -d '/' -f 3 | cut -d' ' -f 1)
+                if test -z "$CODECOV_SOURCE_BRANCH"; then
+                    CODECOV_SOURCE_BRANCH=main
+                fi
+            fi
             i=0
             while /bin/true; do
                 i=$[$i+1]
                 echo "Uploading coverage to codecov (attempt $i)"
-                codecov -X gcovcodecov -X gcov -X s3 --no-color \
-                    -t $CODECOV_TOKEN --root `pwd` -e OS,python \
-                    --name $CODECOV_JOB_NAME $CODECOV_ARGS \
-                    | tee .cover.upload
-                if test $? == 0 -a `grep -i error .cover.upload \
-                        | grep -v branch= | wc -l` -eq 0; then
+                codecovcli -v upload-process --sha $PYOMO_SOURCE_SHA \
+                    --fail-on-error --git-service github --token $CODECOV_TOKEN \
+                    --slug pyomo/pyomo --file coverage.xml --disable-search \
+                    --name $CODECOV_JOB_NAME \
+                    --branch $CODECOV_REPO_OWNER:$CODECOV_SOURCE_BRANCH \
+                    --env OS,python --network-root-folder `pwd` --plugin noop
+                if test $? == 0; then
                     break
                 elif test $i -ge 4; then
                     exit 1
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 553a4f1c3bd..8d1d1e45e3d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,173 @@ Pyomo CHANGELOG
 ===============
 
 
+-------------------------------------------------------------------------------
+Pyomo 6.7.3   (29 May 2024)
+-------------------------------------------------------------------------------
+
+- Core
+  - Deprecate `pyomo.core.plugins.transform.model.to_standard_form()` (#3265)
+  - Reorder definitions to avoid `NameError` in some situations (#3264)
+- Solver Interfaces
+  - NLv2: Fix linear presolver with constant defined vars/external fcns (#3276)
+- Testing
+  - Add URL checking to GHA linting job (#3259, #3261)
+  - Skip Windows Python 3.8 conda GHA job (#3269)
+- Contributed Packages
+  - DoE: Bug fixes for workshop (#3267)
+  - viewer: Update guard for pint import (#3277)
+
+-------------------------------------------------------------------------------
+Pyomo 6.7.2   (9 May 2024)
+-------------------------------------------------------------------------------
+
+- General
+  - Support config domains with either method or attribute domain_name (#3159)
+  - Automate TPL callback registrations (#3167)
+  - Fix type registrations for ExternalFunction arguments (#3168)
+  - Only modify module path and spec for deferred import modules (#3176)
+  - Add "mixed" standard form representation (#3201)
+  - Support "default" dispatchers in `ExitNodeDispatcher` (#3194)
+  - Redefine objective sense as a proper `IntEnum` (#3224)
+  - Fix division-by-0 bug in linear walker (#3246)
+- Core
+  - Allow `Var` objects in `LinearExpression.args` (#3189)
+  - Add type hints to components (#3173)
+  - Simplify expressions generated by `TemplateSumExpression` (#3196)
+  - Make component data public classes (#3221, #3253)
+  - Exploit repeated named expressions in `identify_variables` (#3190)
+- Documentation
+  - NFC: Add link to the HOMOWP companion notebooks (#3195)
+  - Update installation documentation to include Cython instructions (#3208)
+  - Add links to the Pyomo Book Springer page (#3211)
+- Solver Interfaces
+  - Fix division by zero error in linear presolve (#3161)
+  - Subprocess timeout update (#3183)
+  - Solver Refactor - Bug fixes for various components (#3181, #3214, #3228)
+  - NLv2: handle presolved independent linear subsystems (#3193)
+  - Update `LegacySolverWrapper` compatibility with the `pyomo` script (#3202)
+  - Fix mosek_direct to use putqconk instead of putqcon (#3199)
+  - Check _skip_trivial_constraints before the constraint body (#3226)
+  - Fix AMPL solver duplicate funcadd (#3206)
+  - Disable the use of universal newlines in the ipopt_v2 NL file (#3231)
+  - NLv2: fix reporting numbers of nonlinear discrete variables (#3238)
+  - Fix: Get SCIP solving time considering float number with some text (#3234)
+  - Solver Refactor - Add `gurobi_direct` implementation (#3225)
+- Testing
+  - Update TPL package list due to `contrib.solver` (#3164)
+  - Set maxDiff=None on the base TestCase class (#3171)
+  - Testing infrastructure updates (#3175)
+  - Typos update for March 2024 (#3219)
+  - Add openmpi to testing environment to resolve issue in mpi4py (#3236, #3239)
+  - Skip black 24.4.1 due to a bug in the parser (#3247)
+  - Skip tests on draft and WIP pull requests (#3223)
+  - Update GHA to grab gurobipy from PyPI (#3254)
+- GDP
+  - Use private_data for all original / transformed component mappings (#3166)
+  - Fix a bug in gdp.bigm transformation for nested GDPs (#3213)
+- Contributed Packages
+  - APPSI: cmodel: handle non-mutable params in var / constraint bounds (#3182)
+  - APPSI: Allow APPSI FBBT to handle nested named Expressions (#3185)
+  - APPSI: Add MAiNGO solver interface (#3165)
+  - CP: Add SequenceVar and other logical expressions for scheduling (#3227)
+  - DoE: Bug fixes (#3245)
+  - iis: Add minimal intractable system infeasibility diagnostics (#3172)
+  - incidence_analysis: Improve `solve_strongly_connected_components`
+    performance for models with named expressions (#3186)
+  - incidence_analysis: Add function to plot incidence graph in
+    Dulmage-Mendelsohn order (#3207)
+  - incidence_analysis: Require variables and constraints to be specified
+    separately in `IncidenceGraphInterface.remove_nodes` (#3212)
+  - latex_printer: bugfix for set operations / multidimensional sets (#3177)
+  - MindtPy: Add HiGHS support (#2971)
+  - MindtPy: Add call_before_subproblem_solve callback (#3251)
+  - Parmest: New UI using experiment lists (#3160)
+  - piecewise: Add piecewise linear transformations (#3036)
+  - preprocessing: bugfix: intersect domains in variable aggregator (#3241)
+  - PyNumero: Allow CyIpopt to solve problems without objectives (#3163)
+  - PyNumero: Work around bug in CyIpopt 1.4.0 (#3222)
+  - PyNumero: Include "inventory" in readme (#3248)
+  - PyROS: Simplify custom domain validators (#3169)
+  - PyROS: Fix iteration logging for edge case involving discrete sets  (#3170)
+  - PyROS: Update solver timing system (#3198)
+  - simplification: expression simplification using GiNaC or SymPy (#3088)
+
+-------------------------------------------------------------------------------
+Pyomo 6.7.1   (21 Feb 2024)
+-------------------------------------------------------------------------------
+
+- General
+  - Add support for tuples in `ComponentMap`; add `DefaultComponentMap` (#3150)
+  - Update `Path`, `PathList`, and `IsInstance` Domain Validators (#3144)
+  - Remove usage of `__all__` (#3142)
+  - Extend Path and Type Checking Validators of `common.config` (#3140)
+  - Update Copyright Statements (#3139)
+  - Update `ExitNodeDispatcher` to better support extensibility (#3125)
+  - Create contributors data gathering script (#3117)
+  - Prevent duplicate entries in ConfigDict declaration order (#3116)
+  - Remove unnecessary `__future__` imports (#3109)
+  - Import pandas through pyomo.common.dependencies (#3102)
+  - Update links to workshop slides (#3079)
+  - Remove incorrect use of identity (is) comparisons (#3061)
+- Core
+  - Add `Block.register_private_data_initializer()` (#3153)
+  - Generalize the simple_constraint_rule decorator (#3152)
+  - Fix edge case assigning new numeric types to Var/Param with units (#3151)
+  - Add private_data to `_BlockData` (#3138)
+  - IndexComponent create implicit sets as "anonymous" sets (#3075)
+  - Add `all_different` and `count_if` to the logical expression system (#3058)
+  - Fix RangeSet.__len__ when defined by floats (#3119)
+  - Overhaul the `Suffix` component (#3072)
+  - Enforce expression immutability in `expr.args` (#3099)
+  - Improve NumPy registration when assigning numpy to Param (#3093)
+  - Track changes in PyPy behavior introduced in 7.3.14 (#3087)
+  - Remove automatic numpy import (#3077)
+  - Fix `range_difference` for Sets with nonzero anchor points (#3063)
+  - Clarify errors raised by accessing Sets by positional index (#3062)
+- Documentation
+  - Update intersphinx links, remove docs for nonfunctional code (#3155)
+  - Update MPC documentation and citation (#3148)
+  - Fix an error in the documentation for LinearExpression (#3090)
+  - Fix Pyomo.DoE documentation (#3070)
+  - Fix latex_printer documentation (#3066)
+- Solver Interfaces
+  - Preview release of new solver interfaces as pyomo.contrib.solver
+    (#3137, #3156)
+  - Make error msg more explicit wrt different interfaces (#3141)
+  - NLv2: only raise exception for empty models in the legacy API (#3135)
+  - Add `to_expr()` to AMPLRepn, fix NLWriterInfo return type (#3095)
+- Testing
+  - Update Release Wheel Builder Action (#3149)
+  - Actions Version Update: Address node.js deprecations (#3118)
+  - New Black Major Release (24.1.0) (#3108)
+  - Use scip for PyROS tests (#3104)
+  - Add missing solver dependency flags for OnlineDocs tests (#3094)
+  - Re-enable `contrib.viewer.tests.test_qt.py` (#3085)
+  - Add automated testing of OnlineDocs examples (#3080)
+  - Silence deprecation warnings emitted by Pyomo tests (#3076)
+  - Fix Python 3.12 tests (manage `pyutilib`, `distutils` dependencies) (#3065)
+- DAE
+  - Replace deprecated `numpy.math` alias with standard `math` module (#3074)
+- GDP
+  - Handle nested GDPs correctly in all the transformations (#3145)
+  - Fix bugs in nested models in gdp.hull transformation (#3143)
+  - Various bug fixes in gdp.mbigm transformation (#3073)
+  - Add GDP => MINLP Transformation (#3082)
+- Contributed Packages
+  - GDPopt: Fix lbb solve_data bug (#3133)
+  - GDPopt: Adding missing import for gdpopt.enumerate (#3105)
+  - FBBT: Extend `fbbt.ExpressionBoundsVisitor` to handle relational
+    expressions and Expr_if (#3129)
+  - incidence_analysis: Method to add an edge in IncidenceGraphInterface (#3120)
+  - incidence_analysis: Add subgraph method to IncidencegraphInterface (#3122)
+  - incidence_analysis: Add `ampl_repn` option (#3069)
+  - incidence_analysis: Update documentation (#3067)
+  - interior_point: Resolve test failure due to Mumps update (#3114)
+  - MindtPy: Various bug fixes (#3034)
+  - PyROS: Update Solver Argument Resolution and Validation Routines (#3126)
+  - PyROS: Update Subproblem Initialization Routines (#3071)
+  - PyROS: Fix DR polishing under nominal objective focus (#3060)
+
 -------------------------------------------------------------------------------
 Pyomo 6.7.0   (29 Nov 2023)
 -------------------------------------------------------------------------------
diff --git a/LICENSE.md b/LICENSE.md
index 192d315e4b5..9fd5d9b810c 100644
--- a/LICENSE.md
+++ b/LICENSE.md
@@ -1,7 +1,7 @@
 LICENSE
 =======
 
-Copyright (c) 2008-2022 National Technology and Engineering Solutions of
+Copyright (c) 2008-2024 National Technology and Engineering Solutions of
 Sandia, LLC . Under the terms of Contract DE-NA0003525 with National
 Technology and Engineering Solutions of Sandia, LLC , the U.S.
 Government retains certain rights in this software.
diff --git a/README.md b/README.md
index 2f8a25403c2..707f1a06c5a 100644
--- a/README.md
+++ b/README.md
@@ -71,8 +71,11 @@ version, we will remove testing for that Python version.
 
 ### Tutorials and Examples
 
+* [Pyomo — Optimization Modeling in Python](https://link.springer.com/book/10.1007/978-3-030-68928-5)
 * [Pyomo Workshop Slides](https://github.com/Pyomo/pyomo-tutorials/blob/main/Pyomo-Workshop-December-2023.pdf)
 * [Prof. Jeffrey Kantor's Pyomo Cookbook](https://jckantor.github.io/ND-Pyomo-Cookbook/)
+* The [companion notebooks](https://mobook.github.io/MO-book/intro.html)
+  for *Hands-On Mathematical Optimization with Python*
 * [Pyomo Gallery](https://github.com/Pyomo/PyomoGallery)
 
 ### Getting Help
@@ -83,7 +86,7 @@ To get help from the Pyomo community ask a question on one of the following:
 
 ### Developers
 
-Pyomo development moved to this repository in June, 2016 from
+Pyomo development moved to this repository in June 2016 from
 Sandia National Laboratories. Developer discussions are hosted by
 [Google Groups](https://groups.google.com/forum/#!forum/pyomo-developers).
 
diff --git a/RELEASE.md b/RELEASE.md
index 03baa803ac9..e42469cbad5 100644
--- a/RELEASE.md
+++ b/RELEASE.md
@@ -1,4 +1,4 @@
-We are pleased to announce the release of Pyomo 6.7.0.
+We are pleased to announce the release of Pyomo 6.7.3.
 
 Pyomo is a collection of Python software packages that supports a
 diverse set of optimization capabilities for formulating and analyzing
@@ -9,8 +9,15 @@ The following are highlights of the 6.7 release series:
  - Added support for Python 3.12
  - Removed support for Python 3.7
  - New writer for converting linear models to matrix form
+ - Improved handling of nested GDPs
+ - Redesigned user API for parameter estimation
  - New packages:
-    - latex_printer (print Pyomo models to a LaTeX compatible format)
+    - iis: new capability for identifying minimal intractable systems
+    - latex_printer: print Pyomo models to a LaTeX compatible format
+    - contrib.solver: preview of redesigned solver interfaces
+    - simplification: simplify Pyomo expressions
+ - New solver interfaces
+    - MAiNGO: Mixed-integer nonlinear global optimization
  - ...and of course numerous minor bug fixes and performance enhancements
 
 A full list of updates and changes is available in the
diff --git a/.codecov.yml b/codecov.yml
similarity index 54%
rename from .codecov.yml
rename to codecov.yml
index 6b88f948fe1..318a907905f 100644
--- a/.codecov.yml
+++ b/codecov.yml
@@ -1,19 +1,21 @@
+codecov:
+  notify:
+    # GHA: 5, Jenkins: 11
+    # Accurate as of July 3, 2024
+    # Potential to change when Python versions change
+    after_n_builds: 16
+    wait_for_ci: true
 coverage:
-  range: "50...100"
+  range:
+  - 50.0
+  - 100.0
   status:
+    patch:
+      default:
+        # Force patches to be covered at the level of the codebase
+        threshold: 0.0
     project:
       default:
         # Allow overall coverage to drop to avoid failures due to code
         # cleanup or CI unavailability/lag
-        threshold: 5%
-    patch:
-      default:
-        # Force patches to be covered at the level of the codebase
-        threshold: 0%
-#  ci:
-#    - !ci.appveyor.com
-codecov:
-  notify:
-    # GHA: 4, Jenkins: 8
-    after_n_builds: 12  # all
-    wait_for_ci: yes
+        threshold: 5.0
diff --git a/conftest.py b/conftest.py
index df5b0f31e59..34b366f9fd6 100644
--- a/conftest.py
+++ b/conftest.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -11,6 +11,22 @@
 
 import pytest
 
+_implicit_markers = {'default'}
+_extended_implicit_markers = _implicit_markers.union({'solver'})
+
+
+def pytest_collection_modifyitems(items):
+    """
+    This method will mark any unmarked tests with the implicit marker ('default')
+
+    """
+    for item in items:
+        try:
+            next(item.iter_markers())
+        except StopIteration:
+            for marker in _implicit_markers:
+                item.add_marker(getattr(pytest.mark, marker))
+
 
 def pytest_runtest_setup(item):
     """
@@ -32,13 +48,10 @@ def pytest_runtest_setup(item):
     the default mode; but if solver tests are also marked with an explicit
     category (e.g., "expensive"), we will skip them.
     """
-    marker = item.iter_markers()
     solvernames = [mark.args[0] for mark in item.iter_markers(name="solver")]
     solveroption = item.config.getoption("--solver")
     markeroption = item.config.getoption("-m")
-    implicit_markers = ['default']
-    extended_implicit_markers = implicit_markers + ['solver']
-    item_markers = set(mark.name for mark in marker)
+    item_markers = set(mark.name for mark in item.iter_markers())
     if solveroption:
         if solveroption not in solvernames:
             pytest.skip("SKIPPED: Test not marked {!r}".format(solveroption))
@@ -46,9 +59,9 @@ def pytest_runtest_setup(item):
     elif markeroption:
         return
     elif item_markers:
-        if not set(implicit_markers).issubset(
-            item_markers
-        ) and not item_markers.issubset(set(extended_implicit_markers)):
+        if not _implicit_markers.issubset(item_markers) and not item_markers.issubset(
+            _extended_implicit_markers
+        ):
             pytest.skip('SKIPPED: Only running default, solver, and unmarked tests.')
 
 
diff --git a/doc/OnlineDocs/advanced_topics/flattener/index.rst b/doc/OnlineDocs/advanced_topics/flattener/index.rst
index 377de5233ec..f9dd8ea6abb 100644
--- a/doc/OnlineDocs/advanced_topics/flattener/index.rst
+++ b/doc/OnlineDocs/advanced_topics/flattener/index.rst
@@ -30,8 +30,9 @@ The ``pyomo.dae.flatten`` module aims to address this use case by providing
 utilities to generate all components indexed, explicitly or implicitly, by
 user-provided sets.
 
-**When we say "flatten a model," we mean "generate all components in the model,
-preserving all user-specified indexing sets."**
+**When we say "flatten a model," we mean "recursively generate all components in
+the model," where a component can be indexed only by user-specified indexing
+sets (or is not indexed at all)**.
 
 Data structures
 ---------------
@@ -42,3 +43,23 @@ Slices are necessary as they can encode "implicit indexing" -- where a
 component is contained in an indexed block. It is natural to return references
 to these slices, so they may be accessed and manipulated like any other
 component.
+
+Citation
+--------
+If you use the ``pyomo.dae.flatten`` module in your research, we would appreciate
+you citing the following paper, which gives more detail about the motivation for
+and examples of using this functinoality.
+
+.. code-block:: bibtex
+
+    @article{parker2023mpc,
+    title = {Model predictive control simulations with block-hierarchical differential-algebraic process models},
+    journal = {Journal of Process Control},
+    volume = {132},
+    pages = {103113},
+    year = {2023},
+    issn = {0959-1524},
+    doi = {https://doi.org/10.1016/j.jprocont.2023.103113},
+    url = {https://www.sciencedirect.com/science/article/pii/S0959152423002007},
+    author = {Robert B. Parker and Bethany L. Nicholson and John D. Siirola and Lorenz T. Biegler},
+    }
diff --git a/doc/OnlineDocs/bibliography.rst b/doc/OnlineDocs/bibliography.rst
index 6cbb96d3bfb..c12d3f81d8c 100644
--- a/doc/OnlineDocs/bibliography.rst
+++ b/doc/OnlineDocs/bibliography.rst
@@ -39,6 +39,8 @@ Bibliography
                   John D. Siirola, Jean-Paul Watson, and David L. Woodruff.
                   Pyomo - Optimization Modeling in Python, 3rd Edition.
                   Vol. 67. Springer, 2021.
+                  doi: `10.1007/978-3-030-68928-5
+                  <https://doi.org/10.1007/978-3-030-68928-5>`_
 
 .. [PyomoJournal] William E. Hart, Jean-Paul Watson, David L. Woodruff.
                   "Pyomo: modeling and solving mathematical programs in
diff --git a/doc/OnlineDocs/conf.py b/doc/OnlineDocs/conf.py
index ef6510daedf..a06ccfbc9bd 100644
--- a/doc/OnlineDocs/conf.py
+++ b/doc/OnlineDocs/conf.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 #!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 #
@@ -46,8 +57,8 @@
     'numpy': ('https://numpy.org/doc/stable/', None),
     'pandas': ('https://pandas.pydata.org/docs/', None),
     'scikit-learn': ('https://scikit-learn.org/stable/', None),
-    'scipy': ('https://docs.scipy.org/doc/scipy/reference/', None),
-    'Sphinx': ('https://www.sphinx-doc.org/en/stable/', None),
+    'scipy': ('https://docs.scipy.org/doc/scipy/', None),
+    'Sphinx': ('https://www.sphinx-doc.org/en/master/', None),
 }
 
 # -- General configuration ------------------------------------------------
@@ -72,6 +83,8 @@
     'sphinx.ext.doctest',
     'sphinx.ext.todo',
     'sphinx_copybutton',
+    'enum_tools.autoenum',
+    'sphinx.ext.autosectionlabel',
     #'sphinx.ext.githubpages',
 ]
 
@@ -259,7 +272,7 @@ def check_output(self, want, got, optionflags):
     yaml_available, networkx_available, matplotlib_available,
     pympler_available, dill_available,
 )
-pint_available = attempt_import('pint', defer_check=False)[1]
+pint_available = attempt_import('pint', defer_import=False)[1]
 from pyomo.contrib.parmest.parmest import parmest_available
 
 import pyomo.environ as _pe # (trigger all plugin registrations)
diff --git a/doc/OnlineDocs/contributed_packages/iis.rst b/doc/OnlineDocs/contributed_packages/iis.rst
index 98cb9e30771..fa97c2f8c61 100644
--- a/doc/OnlineDocs/contributed_packages/iis.rst
+++ b/doc/OnlineDocs/contributed_packages/iis.rst
@@ -1,6 +1,135 @@
+Infeasibility Diagnostics
+!!!!!!!!!!!!!!!!!!!!!!!!!
+
+There are two closely related tools for infeasibility diagnosis:
+
+  - :ref:`Infeasible Irreducible System (IIS) Tool`
+  - :ref:`Minimal Intractable System finder (MIS) Tool`
+
+The first simply provides a conduit for solvers that compute an
+infeasible irreducible system (e.g., Cplex, Gurobi, or Xpress).  The
+second provides similar functionality, but uses the ``mis`` package
+contributed to Pyomo.
+
+
 Infeasible Irreducible System (IIS) Tool
 ========================================
 
 .. automodule:: pyomo.contrib.iis.iis
 
 .. autofunction:: pyomo.contrib.iis.write_iis
+
+Minimal Intractable System finder (MIS) Tool
+============================================
+
+The file ``mis.py`` finds sets of actions that each, independently,
+would result in feasibility.  The zero-tolerance is whatever the
+solver uses, so users may want to post-process output if it is going
+to be used for analysis. It also computes a minimal intractable system
+(which is not guaranteed to be unique).  It was written by Ben Knueven
+as part of the watertap project (https://github.com/watertap-org/watertap)
+and is therefore governed by a license shown
+at the top of ``mis.py``.
+
+The algorithms come from John Chinneck's slides, see: https://www.sce.carleton.ca/faculty/chinneck/docs/CPAIOR07InfeasibilityTutorial.pdf
+
+Solver
+------
+
+At the time of this writing, you need to use IPopt even for LPs.
+
+Quick Start
+-----------
+
+The file ``trivial_mis.py`` is a tiny example listed at the bottom of
+this help file, which references a Pyomo model with the Python variable
+`m` and has these lines:
+
+.. code-block:: python
+
+   from pyomo.contrib.mis import compute_infeasibility_explanation
+   ipopt = pyo.SolverFactory("ipopt")
+   compute_infeasibility_explanation(m, solver=ipopt)
+
+.. Note::
+   This is done instead of solving the problem.
+   
+.. Note::
+   IDAES users can pass ``get_solver()`` imported from ``ideas.core.solvers``
+   as the solver.
+
+Interpreting the Output
+-----------------------
+
+Assuming the dependencies are installed, running ``trivial_mis.py``
+(shown below) will
+produce a lot of warnings from IPopt and then meaningful output (using a logger).
+
+Repair Options
+^^^^^^^^^^^^^^
+
+This output for the trivial example shows three independent ways that the model could be rendered feasible:
+
+
+.. code-block:: text
+   
+   Model Trivial Quad may be infeasible. A feasible solution was found with only the following variable bounds relaxed:
+	ub of var x[1] by 4.464126126706818e-05
+	lb of var x[2] by 0.9999553410114216
+   Another feasible solution was found with only the following variable bounds relaxed:
+	lb of var x[1] by 0.7071067726864677
+	ub of var x[2] by 0.41421355687130673
+	ub of var y by 0.7071067651855212
+   Another feasible solution was found with only the following inequality constraints, equality constraints, and/or variable bounds relaxed:
+	constraint: c by 0.9999999861866736
+
+
+Minimal Intractable System (MIS)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+This output shows a minimal intractable system:
+
+
+.. code-block:: text
+
+   Computed Minimal Intractable System (MIS)!
+   Constraints / bounds in MIS:
+	lb of var x[2]
+	lb of var x[1]
+	constraint: c
+   
+Constraints / bounds in guards for stability
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+This part of the report is for nonlinear programs (NLPs).
+
+When we’re trying to reduce the constraint set, for an NLP there may be constraints that when missing cause the solver 
+to fail in some catastrophic fashion. In this implementation this is interpreted as failing to get a `results` 
+object back from the call to `solve`. In these cases we keep the constraint in the problem but it’s in the 
+set of “guard” constraints – we can’t really be sure they’re a source of infeasibility or not, 
+just that “bad things” happen when they’re not included.
+
+Perhaps ideally we would put a constraint in the “guard” set if IPopt failed to converge, and only put it in the 
+MIS if IPopt converged to a point of local infeasibility. However, right now the code generally makes the 
+assumption that if IPopt fails to converge the subproblem is infeasible, though obviously that is far from the truth. 
+Hence for difficult NLPs even the “Phase 1” may “fail” – in that when finished the subproblem containing just the 
+constraints in the elastic filter may be feasible -- because IPopt failed to converge and we assumed that meant the 
+subproblem was not feasible.
+
+Dealing with NLPs is far from clean, but that doesn’t mean the tool can’t return useful results even when its assumptions are not satisfied.
+
+trivial_mis.py
+--------------
+
+.. code-block:: python
+
+   import pyomo.environ as pyo
+   m = pyo.ConcreteModel("Trivial Quad")
+   m.x = pyo.Var([1,2], bounds=(0,1))
+   m.y = pyo.Var(bounds=(0, 1))
+   m.c = pyo.Constraint(expr=m.x[1] * m.x[2] == -1)
+   m.d = pyo.Constraint(expr=m.x[1] + m.y >= 1)
+
+   from pyomo.contrib.mis import compute_infeasibility_explanation
+   ipopt = pyo.SolverFactory("ipopt")
+   compute_infeasibility_explanation(m, solver=ipopt)
diff --git a/doc/OnlineDocs/contributed_packages/mpc/api.rst b/doc/OnlineDocs/contributed_packages/mpc/api.rst
new file mode 100644
index 00000000000..2752fea8af6
--- /dev/null
+++ b/doc/OnlineDocs/contributed_packages/mpc/api.rst
@@ -0,0 +1,10 @@
+.. _mpc_api:
+
+API Reference
+=============
+
+.. toctree::
+   data.rst
+   conversion.rst
+   interface.rst
+   modeling.rst
diff --git a/doc/OnlineDocs/contributed_packages/mpc/conversion.rst b/doc/OnlineDocs/contributed_packages/mpc/conversion.rst
new file mode 100644
index 00000000000..9d9406edb75
--- /dev/null
+++ b/doc/OnlineDocs/contributed_packages/mpc/conversion.rst
@@ -0,0 +1,5 @@
+Data Conversion
+===============
+
+.. automodule:: pyomo.contrib.mpc.data.convert
+   :members:
diff --git a/doc/OnlineDocs/contributed_packages/mpc/data.rst b/doc/OnlineDocs/contributed_packages/mpc/data.rst
new file mode 100644
index 00000000000..73cb6543b1e
--- /dev/null
+++ b/doc/OnlineDocs/contributed_packages/mpc/data.rst
@@ -0,0 +1,17 @@
+Data Structures
+===============
+
+.. automodule:: pyomo.contrib.mpc.data.get_cuid
+   :members:
+
+.. automodule:: pyomo.contrib.mpc.data.dynamic_data_base
+   :members:
+
+.. automodule:: pyomo.contrib.mpc.data.scalar_data
+   :members:
+
+.. automodule:: pyomo.contrib.mpc.data.series_data
+   :members:
+
+.. automodule:: pyomo.contrib.mpc.data.interval_data
+   :members:
diff --git a/doc/OnlineDocs/contributed_packages/mpc/index.rst b/doc/OnlineDocs/contributed_packages/mpc/index.rst
index b93abf223e2..e512d1a6ef5 100644
--- a/doc/OnlineDocs/contributed_packages/mpc/index.rst
+++ b/doc/OnlineDocs/contributed_packages/mpc/index.rst
@@ -1,7 +1,7 @@
 MPC
 ===
 
-This package contains data structures and utilities for dynamic optimization
+Pyomo MPC contains data structures and utilities for dynamic optimization
 and rolling horizon applications, e.g. model predictive control.
 
 .. toctree::
@@ -10,3 +10,23 @@ and rolling horizon applications, e.g. model predictive control.
    overview.rst
    examples.rst
    faq.rst
+   api.rst
+
+Citation
+--------
+
+If you use Pyomo MPC in your research, please cite the following paper:
+
+.. code-block:: bibtex
+
+    @article{parker2023mpc,
+    title = {Model predictive control simulations with block-hierarchical differential-algebraic process models},
+    journal = {Journal of Process Control},
+    volume = {132},
+    pages = {103113},
+    year = {2023},
+    issn = {0959-1524},
+    doi = {https://doi.org/10.1016/j.jprocont.2023.103113},
+    url = {https://www.sciencedirect.com/science/article/pii/S0959152423002007},
+    author = {Robert B. Parker and Bethany L. Nicholson and John D. Siirola and Lorenz T. Biegler},
+    }
diff --git a/doc/OnlineDocs/contributed_packages/mpc/interface.rst b/doc/OnlineDocs/contributed_packages/mpc/interface.rst
new file mode 100644
index 00000000000..eb5bac548fd
--- /dev/null
+++ b/doc/OnlineDocs/contributed_packages/mpc/interface.rst
@@ -0,0 +1,8 @@
+Interfaces
+==========
+
+.. automodule:: pyomo.contrib.mpc.interfaces.model_interface
+   :members:
+
+.. automodule:: pyomo.contrib.mpc.interfaces.var_linker
+   :members:
diff --git a/doc/OnlineDocs/contributed_packages/mpc/modeling.rst b/doc/OnlineDocs/contributed_packages/mpc/modeling.rst
new file mode 100644
index 00000000000..cbae03161b1
--- /dev/null
+++ b/doc/OnlineDocs/contributed_packages/mpc/modeling.rst
@@ -0,0 +1,11 @@
+Modeling Components
+===================
+
+.. automodule:: pyomo.contrib.mpc.modeling.constraints
+   :members:
+
+.. automodule:: pyomo.contrib.mpc.modeling.cost_expressions
+   :members:
+
+.. automodule:: pyomo.contrib.mpc.modeling.terminal
+   :members:
diff --git a/doc/OnlineDocs/contributed_packages/mpc/overview.rst b/doc/OnlineDocs/contributed_packages/mpc/overview.rst
index f5dbe85e523..f3bc7504b59 100644
--- a/doc/OnlineDocs/contributed_packages/mpc/overview.rst
+++ b/doc/OnlineDocs/contributed_packages/mpc/overview.rst
@@ -189,7 +189,7 @@ a tracking cost expression.
    >>> m.setpoint_idx = var_set
    >>> m.tracking_cost = tr_cost
    >>> m.tracking_cost.pprint()
-   tracking_cost : Size=6, Index=tracking_cost_index
+   tracking_cost : Size=6, Index=setpoint_idx*time
        Key    : Expression
        (0, 0) : (var[0,A] - 0.5)**2
        (0, 1) : (var[1,A] - 0.5)**2
diff --git a/doc/OnlineDocs/contributed_packages/parmest/datarec.rst b/doc/OnlineDocs/contributed_packages/parmest/datarec.rst
index 6b721377e46..2260450192c 100644
--- a/doc/OnlineDocs/contributed_packages/parmest/datarec.rst
+++ b/doc/OnlineDocs/contributed_packages/parmest/datarec.rst
@@ -3,56 +3,52 @@
 Data Reconciliation 
 ====================
 
-The method :class:`~pyomo.contrib.parmest.parmest.Estimator.theta_est`
-can optionally return model values.  This feature can be used to return
-reconciled data using a user specified objective. In this case, the list
-of variable names the user wants to estimate (theta_names) is set to an
-empty list and the objective function is defined to minimize
+The optional argument ``return_values`` in :class:`~pyomo.contrib.parmest.parmest.Estimator.theta_est`
+can be used for data reconciliation or to return model values based on the specified objective. 
+
+For data reconciliation, the ``m.unknown_parameters`` is empty
+and the objective function is defined to minimize
 measurement to model error. Note that the model used for data
 reconciliation may differ from the model used for parameter estimation.
 
-The following example illustrates the use of parmest for data
-reconciliation.  The functions
+The functions
 :class:`~pyomo.contrib.parmest.graphics.grouped_boxplot` or
 :class:`~pyomo.contrib.parmest.graphics.grouped_violinplot` can be used
 to visually compare the original and reconciled data.
 
-Here's a stylized code snippet showing how box plots might be created:
-
-.. doctest::
-    :skipif: True
-
-    >>> import pyomo.contrib.parmest.parmest as parmest
-    >>> pest = parmest.Estimator(model_function, data, [], objective_function)
-    >>> obj, theta, data_rec = pest.theta_est(return_values=['A', 'B']) 
-    >>> parmest.graphics.grouped_boxplot(data, data_rec)
-
-Returned Values
-^^^^^^^^^^^^^^^
+The following example from the reactor design subdirectory returns reconciled values for experiment outputs 
+(`ca`, `cb`, `cc`, and `cd`) and then uses those values in 
+parameter estimation (`k1`, `k2`, and `k3`).
 
-Here's a full program that can be run to see returned values (in this case it
-is the response function that is defined in the model file):
+.. literalinclude:: ../../../../pyomo/contrib/parmest/examples/reactor_design/datarec_example.py
+   :language: python
+   
+The following example returns model values from a Pyomo Expression. 
 
 .. doctest::
    :skipif: not ipopt_available or not parmest_available
    
    >>> import pandas as pd   
    >>> import pyomo.contrib.parmest.parmest as parmest
-   >>> from pyomo.contrib.parmest.examples.rooney_biegler.rooney_biegler import rooney_biegler_model
-
-   >>> theta_names = ['asymptote', 'rate_constant']
+   >>> from pyomo.contrib.parmest.examples.rooney_biegler.rooney_biegler import RooneyBieglerExperiment
 
+   >>> # Generate data
    >>> data = pd.DataFrame(data=[[1,8.3],[2,10.3],[3,19.0],
    ...                           [4,16.0],[5,15.6],[7,19.8]],
    ...                     columns=['hour', 'y'])
 
-   >>> def SSE(model, data):  
-   ...     expr = sum((data.y[i]\
-   ...                 - model.response_function[data.hour[i]])**2 for i in data.index)
+   >>> # Create an experiment list
+   >>> exp_list = []
+   >>> for i in range(data.shape[0]):
+   ...     exp_list.append(RooneyBieglerExperiment(data.loc[i, :]))
+
+   >>> # Define objective
+   >>> def SSE(model):
+   ...     expr = (model.experiment_outputs[model.y]
+   ...             - model.response_function[model.experiment_outputs[model.hour]]
+   ...            ) ** 2
    ...     return expr
 
-   >>> pest = parmest.Estimator(rooney_biegler_model, data, theta_names, SSE,
-   ...                          solver_options=None)
+   >>> pest = parmest.Estimator(exp_list, obj_function=SSE, solver_options=None)
    >>> obj, theta, var_values = pest.theta_est(return_values=['response_function'])
    >>> #print(var_values)
-   
diff --git a/doc/OnlineDocs/contributed_packages/parmest/driver.rst b/doc/OnlineDocs/contributed_packages/parmest/driver.rst
index 28238928b83..5881d2748f9 100644
--- a/doc/OnlineDocs/contributed_packages/parmest/driver.rst
+++ b/doc/OnlineDocs/contributed_packages/parmest/driver.rst
@@ -4,7 +4,7 @@ Parameter Estimation
 ==================================
 
 Parameter Estimation using parmest requires a Pyomo model, experimental
-data which defines multiple scenarios, and a list of parameter names
+data which defines multiple scenarios, and parameters
 (thetas) to estimate.  parmest uses Pyomo [PyomoBookII]_ and (optionally) 
 mpi-sppy [mpisppy]_ to solve a
 two-stage stochastic programming problem, where the experimental data is
@@ -36,13 +36,12 @@ which includes the following methods:
    ~pyomo.contrib.parmest.parmest.Estimator.likelihood_ratio_test
    ~pyomo.contrib.parmest.parmest.Estimator.leaveNout_bootstrap_test
 
-Additional functions are available in parmest to group data, plot
-results, and fit distributions to theta values.
+Additional functions are available in parmest to plot
+results and fit distributions to theta values.
 
 .. autosummary::
    :nosignatures:
 
-   ~pyomo.contrib.parmest.parmest.group_data
    ~pyomo.contrib.parmest.graphics.pairwise_plot
    ~pyomo.contrib.parmest.graphics.grouped_boxplot
    ~pyomo.contrib.parmest.graphics.grouped_violinplot
@@ -58,21 +57,33 @@ Section.
 .. testsetup:: *
     :skipif: not __import__('pyomo.contrib.parmest.parmest').contrib.parmest.parmest.parmest_available
 
+    # Data
     import pandas as pd
-    from pyomo.contrib.parmest.examples.rooney_biegler.rooney_biegler import rooney_biegler_model as model_function
-    data = pd.DataFrame(data=[[1,8.3],[2,10.3],[3,19.0],
-                              [4,16.0],[5,15.6],[6,19.8]],
-                        columns=['hour', 'y'])
-    theta_names = ['asymptote', 'rate_constant']
-    def objective_function(model, data):
-        expr = sum((data.y[i] - model.response_function[data.hour[i]])**2 for i in data.index)
+    data = pd.DataFrame(
+        data=[[1, 8.3], [2, 10.3], [3, 19.0], 
+              [4, 16.0], [5, 15.6], [7, 19.8]],
+        columns=['hour', 'y'],
+    )
+
+    # Sum of squared error function
+    def SSE(model):
+        expr = (
+            model.experiment_outputs[model.y]
+            - model.response_function[model.experiment_outputs[model.hour]]
+        ) ** 2
         return expr
 
+    # Create an experiment list
+    from pyomo.contrib.parmest.examples.rooney_biegler.rooney_biegler import RooneyBieglerExperiment
+    exp_list = []
+    for i in range(data.shape[0]):
+        exp_list.append(RooneyBieglerExperiment(data.loc[i, :]))
+
 .. doctest::
     :skipif: not __import__('pyomo.contrib.parmest.parmest').contrib.parmest.parmest.parmest_available
 
     >>> import pyomo.contrib.parmest.parmest as parmest
-    >>> pest = parmest.Estimator(model_function, data, theta_names, objective_function)
+    >>> pest = parmest.Estimator(exp_list, obj_function=SSE)
 
 Optionally, solver options can be supplied, e.g.,
 
@@ -80,66 +91,44 @@ Optionally, solver options can be supplied, e.g.,
     :skipif: not __import__('pyomo.contrib.parmest.parmest').contrib.parmest.parmest.parmest_available
 
     >>> solver_options = {"max_iter": 6000}
-    >>> pest = parmest.Estimator(model_function, data, theta_names, objective_function, solver_options)
-        
-
-
-Model function
---------------
-
-The first argument is a function which uses data for a single scenario
-to return a populated and initialized Pyomo model for that scenario.
-
-Parameters that the user would like to estimate can be defined as
-**mutable parameters (Pyomo `Param`) or variables (Pyomo `Var`)**.  
-Within parmest, any parameters that are to be estimated are converted to unfixed variables. 
-Variables that are to be estimated are also unfixed.
-
-The model does not have to be specifically written as a 
-two-stage stochastic programming problem for parmest. 
-That is, parmest can modify the
-objective, see :ref:`ObjFunction` below.
-
-Data
-----
-
-The second argument is the data which will be used to populate the Pyomo
-model.  Supported data formats include:
-
-* **Pandas Dataframe** where each row is a separate scenario and column
-  names refer to observed quantities.  Pandas DataFrames are easily
-  stored and read in from csv, excel, or databases, or created directly
-  in Python.
-* **List of Pandas Dataframe** where each entry in the list is a separate scenario. 
-  Dataframes store observed quantities, referenced by index and column.
-* **List of dictionaries** where each entry in the list is a separate
-  scenario and the keys (or nested keys) refer to observed quantities.
-  Dictionaries are often preferred over DataFrames when using static and
-  time series data.  Dictionaries are easily stored and read in from
-  json or yaml files, or created directly in Python.
-* **List of json file names** where each entry in the list contains a
-  json file name for a separate scenario.  This format is recommended
-  when using large datasets in parallel computing.
-
-The data must be compatible with the model function that returns a
-populated and initialized Pyomo model for a single scenario.  Data can
-include multiple entries per variable (time series and/or duplicate
-sensors).  This information can be included in custom objective
-functions, see :ref:`ObjFunction` below.
-
-Theta names
------------
-
-The third argument is a list of parameters or variable names that the user wants to
-estimate.  The list contains strings with `Param` and/or `Var` names from the Pyomo
-model.
+    >>> pest = parmest.Estimator(exp_list, obj_function=SSE, solver_options=solver_options)
+
+
+List of experiment objects
+--------------------------
+
+The first argument is a list of experiment objects which is used to
+create one labeled model for each expeirment. 
+The template :class:`~pyomo.contrib.parmest.experiment.Experiment` 
+can be used to generate a list of experiment objects.
+
+A labeled Pyomo model ``m`` has the following additional suffixes (Pyomo `Suffix`):
+
+* ``m.experiment_outputs`` which defines experiment output (Pyomo `Param`, `Var`, or `Expression`)
+  and their associated data values (float, int).
+* ``m.unknown_parameters`` which defines the mutable parameters or variables (Pyomo `Param` or `Var`)
+  to estimate along with their component unique identifier (Pyomo `ComponentUID`). 
+  Within parmest, any parameters that are to be estimated are converted to unfixed variables. 
+  Variables that are to be estimated are also unfixed.
+
+The experiment class has one required method:
+
+* :class:`~pyomo.contrib.parmest.experiment.Experiment.get_labeled_model` which returns the labeled Pyomo model.
+  Note that the model does not have to be specifically written as a 
+  two-stage stochastic programming problem for parmest. 
+  That is, parmest can modify the
+  objective, see :ref:`ObjFunction` below.
+ 
+Parmest comes with several :ref:`examplesection` that illustrates how to set up the list of experiment objects.
+The examples commonly include additional :class:`~pyomo.contrib.parmest.experiment.Experiment` class methods to
+create the model, finalize the model, and label the model.  The user can customize methods to suit their needs.
 
 .. _ObjFunction:
 
 Objective function
 ------------------
 
-The fourth argument is an optional argument which defines the
+The second argument is an optional argument which defines the
 optimization objective function to use in parameter estimation.  
 
 If no objective function is specified, the Pyomo model is used "as is" and
@@ -150,20 +139,27 @@ stochastic programming problem.
 If the Pyomo model is not written as a two-stage stochastic programming problem in
 this format, and/or if the user wants to use an objective that is
 different than the original model, a custom objective function can be
-defined for parameter estimation.  The objective function arguments
-include `model` and `data` and the objective function returns a Pyomo
+defined for parameter estimation.  The objective function has a single argument, 
+which is the model from a single experiment.
+The objective function returns a Pyomo
 expression which is used to define "SecondStageCost".  The objective
 function can be used to customize data points and weights that are used
 in parameter estimation.
 
+Parmest includes one built in objective function to compute the sum of squared errors ("SSE") between the 
+``m.experiment_outputs`` model values and data values.
+
 Suggested initialization procedure for parameter estimation problems
 --------------------------------------------------------------------
 
 To check the quality of initial guess values provided for the fitted parameters, we suggest solving a 
 square instance of the problem prior to solving the parameter estimation problem using the following steps:
 
-1. Create :class:`~pyomo.contrib.parmest.parmest.Estimator` object. To initialize the parameter estimation solve from the square problem solution, set optional argument ``solver_options = {bound_push: 1e-8}``.
+1. Create :class:`~pyomo.contrib.parmest.parmest.Estimator` object. To initialize the parameter 
+estimation solve from the square problem solution, set optional argument ``solver_options = {bound_push: 1e-8}``.
 
-2. Call :class:`~pyomo.contrib.parmest.parmest.Estimator.objective_at_theta` with optional argument ``(initialize_parmest_model=True)``. Different initial guess values for the fitted parameters can be provided using optional argument `theta_values` (**Pandas Dataframe**)
+2. Call :class:`~pyomo.contrib.parmest.parmest.Estimator.objective_at_theta` with optional 
+argument ``(initialize_parmest_model=True)``. Different initial guess values for the fitted 
+parameters can be provided using optional argument `theta_values` (**Pandas Dataframe**)
 
 3. Solve parameter estimation problem by calling :class:`~pyomo.contrib.parmest.parmest.Estimator.theta_est`
diff --git a/doc/OnlineDocs/contributed_packages/parmest/examples.rst b/doc/OnlineDocs/contributed_packages/parmest/examples.rst
index 793ff3d0c8d..a59d79dfa2b 100644
--- a/doc/OnlineDocs/contributed_packages/parmest/examples.rst
+++ b/doc/OnlineDocs/contributed_packages/parmest/examples.rst
@@ -20,7 +20,7 @@ Additional use cases include:
 * Parameter estimation using mpi4py, the example saves results to a file
   for later analysis/graphics (semibatch example)
 
-The description below uses the reactor design example.  The file
+The example below uses the reactor design example.  The file
 **reactor_design.py** includes a function which returns an populated
 instance of the Pyomo model.  Note that the model is defined to maximize
 `cb` and that `k1`, `k2`, and `k3` are fixed.  The _main_ program is
diff --git a/doc/OnlineDocs/contributed_packages/parmest/scencreate.rst b/doc/OnlineDocs/contributed_packages/parmest/scencreate.rst
index 66d41d4c606..b63ac5893c2 100644
--- a/doc/OnlineDocs/contributed_packages/parmest/scencreate.rst
+++ b/doc/OnlineDocs/contributed_packages/parmest/scencreate.rst
@@ -18,5 +18,5 @@ scenarios to the screen, accessing them via the ``ScensItator`` a ``print``
    :language: python
 
 .. note::
-   This example may produce an error message your version of Ipopt is not based
+   This example may produce an error message if your version of Ipopt is not based
    on a good linear solver.
diff --git a/doc/OnlineDocs/contributed_packages/pynumero/backward_compatibility.rst b/doc/OnlineDocs/contributed_packages/pynumero/backward_compatibility.rst
new file mode 100644
index 00000000000..036a00bee62
--- /dev/null
+++ b/doc/OnlineDocs/contributed_packages/pynumero/backward_compatibility.rst
@@ -0,0 +1,14 @@
+Backward Compatibility
+======================
+
+While PyNumero is a third-party contribution to Pyomo, we intend to maintain
+the stability of its core functionality. The core functionality of PyNumero
+consists of:
+
+1. The ``NLP`` API and ``PyomoNLP`` implementation of this API
+2. HSL and MUMPS linear solver interfaces
+3. ``BlockVector`` and ``BlockMatrix`` classes
+4. CyIpopt and SciPy solver interfaces
+
+Other parts of PyNumero, such as ``ExternalGreyBoxBlock`` and
+``ImplicitFunctionSolver``, are experimental and subject to change without notice.
diff --git a/doc/OnlineDocs/contributed_packages/pynumero/index.rst b/doc/OnlineDocs/contributed_packages/pynumero/index.rst
index 6ff8b29f812..711bb83eb3b 100644
--- a/doc/OnlineDocs/contributed_packages/pynumero/index.rst
+++ b/doc/OnlineDocs/contributed_packages/pynumero/index.rst
@@ -13,6 +13,7 @@ PyNumero. For more details, see the API documentation (:ref:`pynumero_api`).
    installation.rst
    tutorial.rst
    api.rst
+   backward_compatibility.rst
 
 
 Developers
diff --git a/doc/OnlineDocs/contributed_packages/pynumero/pynumero.sparse.block_vector.rst b/doc/OnlineDocs/contributed_packages/pynumero/pynumero.sparse.block_vector.rst
index 6e1dc1f20e5..c17d3d1df86 100644
--- a/doc/OnlineDocs/contributed_packages/pynumero/pynumero.sparse.block_vector.rst
+++ b/doc/OnlineDocs/contributed_packages/pynumero/pynumero.sparse.block_vector.rst
@@ -77,7 +77,7 @@ NumPy compatible functions:
   * `numpy.arccos() <https://numpy.org/doc/stable/reference/generated/numpy.arccos.html>`_
   * `numpy.sinh() <https://numpy.org/doc/stable/reference/generated/numpy.sinh.html>`_
   * `numpy.cosh() <https://numpy.org/doc/stable/reference/generated/numpy.cosh.html>`_
-  * `numpy.abs() <https://numpy.org/doc/stable/reference/generated/numpy.abs.html>`_
+  * `numpy.abs() <https://numpy.org/doc/stable/reference/generated/numpy.absolute.html>`_
   * `numpy.tanh() <https://numpy.org/doc/stable/reference/generated/numpy.tanh.html>`_
   * `numpy.arccosh() <https://numpy.org/doc/stable/reference/generated/numpy.arccosh.html>`_
   * `numpy.arcsinh() <https://numpy.org/doc/stable/reference/generated/numpy.arcsinh.html>`_
diff --git a/doc/OnlineDocs/contributed_packages/pyros.rst b/doc/OnlineDocs/contributed_packages/pyros.rst
index 3ff1bfccf0e..95049eded8a 100644
--- a/doc/OnlineDocs/contributed_packages/pyros.rst
+++ b/doc/OnlineDocs/contributed_packages/pyros.rst
@@ -142,6 +142,7 @@ PyROS Solver Interface
 
     Otherwise, the solution returned is certified to only be robust feasible.
 
+
 PyROS Uncertainty Sets
 -----------------------------
 Uncertainty sets are represented by subclasses of
@@ -518,7 +519,7 @@ correspond to first-stage degrees of freedom.
 
   >>> # === Designate which variables correspond to first-stage
   >>> #     and second-stage degrees of freedom ===
-  >>> first_stage_variables =[
+  >>> first_stage_variables = [
   ...     m.x1, m.x2, m.x3, m.x4, m.x5, m.x6,
   ...     m.x19, m.x20, m.x21, m.x22, m.x23, m.x24, m.x31,
   ... ]
@@ -539,7 +540,7 @@ correspond to first-stage degrees of freedom.
   ...     load_solution=False,
   ... )
   ==============================================================================
-  PyROS: The Pyomo Robust Optimization Solver.
+  PyROS: The Pyomo Robust Optimization Solver...
   ...
   ------------------------------------------------------------------------------
   Robust optimal solution identified.
@@ -657,6 +658,54 @@ For this example, we notice a ~25% decrease in the final objective
 value when switching from a static decision rule (no second-stage recourse)
 to an affine decision rule.
 
+
+Specifying Arguments Indirectly Through ``options``
+"""""""""""""""""""""""""""""""""""""""""""""""""""
+Like other Pyomo solver interface methods,
+:meth:`~pyomo.contrib.pyros.PyROS.solve`
+provides support for specifying options indirectly by passing
+a keyword argument ``options``, whose value must be a :class:`dict`
+mapping names of arguments to :meth:`~pyomo.contrib.pyros.PyROS.solve`
+to their desired values.
+For example, the ``solve()`` statement in the
+:ref:`two-stage problem snippet <example-two-stg>`
+could have been equivalently written as:
+
+.. doctest::
+  :skipif: not (baron.available() and baron.license_is_valid())
+
+  >>> results_2 = pyros_solver.solve(
+  ...     model=m,
+  ...     first_stage_variables=first_stage_variables,
+  ...     second_stage_variables=second_stage_variables,
+  ...     uncertain_params=uncertain_parameters,
+  ...     uncertainty_set=box_uncertainty_set,
+  ...     local_solver=local_solver,
+  ...     global_solver=global_solver,
+  ...     options={
+  ...         "objective_focus": pyros.ObjectiveType.worst_case,
+  ...         "solve_master_globally": True,
+  ...         "decision_rule_order": 1,
+  ...     },
+  ... )
+  ==============================================================================
+  PyROS: The Pyomo Robust Optimization Solver...
+  ...
+  ------------------------------------------------------------------------------
+  Robust optimal solution identified.
+  ------------------------------------------------------------------------------
+  ...
+  ------------------------------------------------------------------------------
+  All done. Exiting PyROS.
+  ==============================================================================
+
+In the event an argument is passed directly
+by position or keyword, *and* indirectly through ``options``,
+an appropriate warning is issued,
+and the value passed directly takes precedence over the value
+passed through ``options``.
+
+
 The Price of Robustness
 """"""""""""""""""""""""
 In conjunction with standard Python control flow tools,
@@ -854,10 +903,10 @@ Observe that the log contains the following information:
    :linenos:
 
    ==============================================================================
-   PyROS: The Pyomo Robust Optimization Solver, v1.2.9.
-          Pyomo version: 6.7.0
+   PyROS: The Pyomo Robust Optimization Solver, v1.2.11.
+          Pyomo version: 6.7.2
           Commit hash: unknown
-          Invoked at UTC 2023-12-16T00:00:00.000000
+          Invoked at UTC 2024-03-28T00:00:00.000000
 
    Developed by: Natalie M. Isenberg (1), Jason A. F. Sherman (1),
                  John D. Siirola (2), Chrysanthos E. Gounaris (1)
@@ -877,6 +926,7 @@ Observe that the log contains the following information:
     keepfiles=False
     tee=False
     load_solution=True
+    symbolic_solver_labels=False
     objective_focus=<ObjectiveType.worst_case: 1>
     nominal_uncertain_param_vals=[0.13248000000000001, 4.97, 4.97, 1800]
     decision_rule_order=1
diff --git a/doc/OnlineDocs/contribution_guide.rst b/doc/OnlineDocs/contribution_guide.rst
index 10670627546..9ad5bdfee0e 100644
--- a/doc/OnlineDocs/contribution_guide.rst
+++ b/doc/OnlineDocs/contribution_guide.rst
@@ -71,6 +71,10 @@ at least 70% coverage of the lines modified in the PR and prefer coverage
 closer to 90%. We also require that all tests pass before a PR will be 
 merged.
 
+.. note::
+   If you are having issues getting tests to pass on your Pull Request,
+   please tag any of the core developers to ask for help.
+
 The Pyomo main branch provides a Github Actions workflow (configured
 in the ``.github/`` directory) that will test any changes pushed to
 a branch with a subset of the complete test harness that includes
@@ -82,13 +86,16 @@ This will enable the tests to run automatically with each push to your fork.
 
 At any point in the development cycle, a "work in progress" pull request
 may be opened by including '[WIP]' at the beginning of the PR
-title. This allows your code changes to be tested by the full suite of
-Pyomo's automatic
-testing infrastructure. Any pull requests marked '[WIP]' will not be
+title. Any pull requests marked '[WIP]' or draft will not be
 reviewed or merged by the core development team. However, any
 '[WIP]' pull request left open for an extended period of time without
 active development may be marked 'stale' and closed.
 
+.. note::
+   Draft and WIP Pull Requests will **NOT** trigger tests. This is an effort to
+   reduce our CI backlog. Please make use of the provided
+   branch test suite for evaluating / testing draft functionality.
+
 Python Version Support
 ++++++++++++++++++++++
 
@@ -397,50 +404,10 @@ Contrib packages will be tested along with Pyomo.  If test failures
 arise, then these packages will be disabled and an issue will be
 created to resolve these test failures.
 
-The following two examples illustrate the two ways
-that ``pyomo.contrib`` can be used to integrate third-party
-contributions.
-
-Including External Packages
-+++++++++++++++++++++++++++
-
-The `pyomocontrib_simplemodel
-<http://pyomocontrib-simplemodel.readthedocs.io/en/latest/>`_ package
-is derived from Pyomo, and it defines the class SimpleModel that
-illustrates how Pyomo can be used in a simple, less object-oriented
-manner. Specifically, this class mimics the modeling style supported
-by `PuLP <https://github.com/coin-or/pulp>`_.
-
-While ``pyomocontrib_simplemodel`` can be installed and used separate
-from Pyomo, this package is included in ``pyomo/contrib/simplemodel``.
-This allows this package to be referenced as if were defined as a
-subpackage of ``pyomo.contrib``.  For example::
-
-    from pyomo.contrib.simplemodel import *
-    from math import pi
-
-    m = SimpleModel()
-
-    r = m.var('r', bounds=(0,None))
-    h = m.var('h', bounds=(0,None))
-
-    m += 2*pi*r*(r + h)
-    m += pi*h*r**2 == 355
-
-    status = m.solve("ipopt")
-
-This example illustrates that a package can be distributed separate
-from Pyomo while appearing to be included in the ``pyomo.contrib``
-subpackage.  Pyomo requires a separate directory be defined under
-``pyomo/contrib`` for each such package, and the Pyomo developer
-team will approve the inclusion of third-party packages in this
-manner.
-
-
 Contrib Packages within Pyomo
 +++++++++++++++++++++++++++++
 
-Third-party contributions can also be included directly within the
+Third-party contributions can be included directly within the
 ``pyomo.contrib`` package.  The ``pyomo/contrib/example`` package
 provides an example of how this can be done, including a directory
 for plugins and package tests.  For example, this package can be
@@ -458,7 +425,7 @@ import this package, but if an import failure occurs, Pyomo will
 silently ignore it.  Otherwise, this pyomo package will be treated
 like any other.  Specifically:
 
-* Plugin classes defined in this package are loaded when `pyomo.environ` is loaded.
+* Plugin classes defined in this package are loaded when ``pyomo.environ`` is loaded.
 
 * Tests in this package are run with other Pyomo tests.
 
diff --git a/doc/OnlineDocs/developer_reference/future.rst b/doc/OnlineDocs/developer_reference/future.rst
new file mode 100644
index 00000000000..531c0fdb5c6
--- /dev/null
+++ b/doc/OnlineDocs/developer_reference/future.rst
@@ -0,0 +1,3 @@
+
+.. automodule:: pyomo.__future__
+   :noindex:
diff --git a/doc/OnlineDocs/developer_reference/index.rst b/doc/OnlineDocs/developer_reference/index.rst
index 8c29150015c..0feb33cdab9 100644
--- a/doc/OnlineDocs/developer_reference/index.rst
+++ b/doc/OnlineDocs/developer_reference/index.rst
@@ -12,3 +12,5 @@ scripts using Pyomo.
    config.rst
    deprecation.rst
    expressions/index.rst
+   future.rst
+   solvers.rst
diff --git a/doc/OnlineDocs/developer_reference/solvers.rst b/doc/OnlineDocs/developer_reference/solvers.rst
new file mode 100644
index 00000000000..9e3281246f4
--- /dev/null
+++ b/doc/OnlineDocs/developer_reference/solvers.rst
@@ -0,0 +1,351 @@
+Future Solver Interface Changes
+===============================
+
+.. note::
+
+   The new solver interfaces are still under active development.  They
+   are included in the releases as development previews.  Please be
+   aware that APIs and functionality may change with no notice.
+
+   We welcome any feedback and ideas as we develop this capability.
+   Please post feedback on
+   `Issue 1030 <https://github.com/Pyomo/pyomo/issues/1030>`_.
+
+Pyomo offers interfaces into multiple solvers, both commercial and open
+source.  To support better capabilities for solver interfaces, the Pyomo
+team is actively redesigning the existing interfaces to make them more
+maintainable and intuitive for use. A preview of the redesigned
+interfaces can be found in ``pyomo.contrib.solver``.
+
+.. currentmodule:: pyomo.contrib.solver
+
+
+New Interface Usage
+-------------------
+
+The new interfaces are not completely backwards compatible with the
+existing Pyomo solver interfaces.  However, to aid in testing and
+evaluation, we are distributing versions of the new solver interfaces
+that are compatible with the existing ("legacy") solver interface.
+These "legacy" interfaces are registered with the current
+``SolverFactory`` using slightly different names (to avoid conflicts
+with existing interfaces).
+
+.. |br| raw:: html
+
+   <br />
+
+.. list-table:: Available Redesigned Solvers and Names Registered
+                in the SolverFactories
+   :header-rows: 1
+
+   * - Solver
+     - Name registered in the |br| ``pyomo.contrib.solver.factory.SolverFactory``
+     - Name registered in the |br| ``pyomo.opt.base.solvers.LegacySolverFactory``
+   * - Ipopt
+     - ``ipopt``
+     - ``ipopt_v2``
+   * - Gurobi (persistent)
+     - ``gurobi``
+     - ``gurobi_v2``
+   * - Gurobi (direct)
+     - ``gurobi_direct``
+     - ``gurobi_direct_v2``
+
+Using the new interfaces through the legacy interface
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Here we use the new interface as exposed through the existing (legacy)
+solver factory and solver interface wrapper.  This provides an API that
+is compatible with the existing (legacy) Pyomo solver interface and can
+be used with other Pyomo tools / capabilities.
+
+.. testcode::
+   :skipif: not ipopt_available
+
+   import pyomo.environ as pyo
+   from pyomo.contrib.solver.util import assert_optimal_termination
+
+   model = pyo.ConcreteModel()
+   model.x = pyo.Var(initialize=1.5)
+   model.y = pyo.Var(initialize=1.5)
+
+   def rosenbrock(model):
+       return (1.0 - model.x) ** 2 + 100.0 * (model.y - model.x**2) ** 2
+
+   model.obj = pyo.Objective(rule=rosenbrock, sense=pyo.minimize)
+
+   status = pyo.SolverFactory('ipopt_v2').solve(model)
+   assert_optimal_termination(status)
+   model.pprint()
+
+.. testoutput::
+   :skipif: not ipopt_available
+   :hide:
+
+   2 Var Declarations
+   ...
+   3 Declarations: x y obj
+
+In keeping with our commitment to backwards compatibility, both the legacy and
+future methods of specifying solver options are supported:
+
+.. testcode::
+   :skipif: not ipopt_available
+
+   import pyomo.environ as pyo
+
+   model = pyo.ConcreteModel()
+   model.x = pyo.Var(initialize=1.5)
+   model.y = pyo.Var(initialize=1.5)
+
+   def rosenbrock(model):
+       return (1.0 - model.x) ** 2 + 100.0 * (model.y - model.x**2) ** 2
+
+   model.obj = pyo.Objective(rule=rosenbrock, sense=pyo.minimize)
+
+   # Backwards compatible
+   status = pyo.SolverFactory('ipopt_v2').solve(model, options={'max_iter' : 6})
+   # Forwards compatible
+   status = pyo.SolverFactory('ipopt_v2').solve(model, solver_options={'max_iter' : 6})
+   model.pprint()
+
+.. testoutput::
+   :skipif: not ipopt_available
+   :hide:
+
+   2 Var Declarations
+   ...
+   3 Declarations: x y obj
+
+Using the new interfaces directly
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Here we use the new interface by importing it directly:
+
+.. testcode::
+   :skipif: not ipopt_available
+
+   # Direct import
+   import pyomo.environ as pyo
+   from pyomo.contrib.solver.util import assert_optimal_termination
+   from pyomo.contrib.solver.ipopt import Ipopt
+
+   model = pyo.ConcreteModel()
+   model.x = pyo.Var(initialize=1.5)
+   model.y = pyo.Var(initialize=1.5)
+
+   def rosenbrock(model):
+       return (1.0 - model.x) ** 2 + 100.0 * (model.y - model.x**2) ** 2
+
+   model.obj = pyo.Objective(rule=rosenbrock, sense=pyo.minimize)
+
+   opt = Ipopt()
+   status = opt.solve(model)
+   assert_optimal_termination(status)
+   # Displays important results information; only available through the new interfaces
+   status.display()
+   model.pprint()
+
+.. testoutput::
+   :skipif: not ipopt_available
+   :hide:
+
+   solution_loader: ...
+   ...
+   3 Declarations: x y obj
+
+Using the new interfaces through the "new" SolverFactory
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Here we use the new interface by retrieving it from the new ``SolverFactory``:
+
+.. testcode::
+   :skipif: not ipopt_available
+
+   # Import through new SolverFactory
+   import pyomo.environ as pyo
+   from pyomo.contrib.solver.util import assert_optimal_termination
+   from pyomo.contrib.solver.factory import SolverFactory
+
+   model = pyo.ConcreteModel()
+   model.x = pyo.Var(initialize=1.5)
+   model.y = pyo.Var(initialize=1.5)
+
+   def rosenbrock(model):
+       return (1.0 - model.x) ** 2 + 100.0 * (model.y - model.x**2) ** 2
+
+   model.obj = pyo.Objective(rule=rosenbrock, sense=pyo.minimize)
+
+   opt = SolverFactory('ipopt')
+   status = opt.solve(model)
+   assert_optimal_termination(status)
+   # Displays important results information; only available through the new interfaces
+   status.display()
+   model.pprint()
+
+.. testoutput::
+   :skipif: not ipopt_available
+   :hide:
+
+   solution_loader: ...
+   ...
+   3 Declarations: x y obj
+
+Switching all of Pyomo to use the new interfaces
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+We also provide a mechanism to get a "preview" of the future where we
+replace the existing (legacy) SolverFactory and utilities with the new
+(development) version (see :doc:`future`):
+
+.. testcode::
+   :skipif: not ipopt_available
+
+   # Change default SolverFactory version
+   import pyomo.environ as pyo
+   from pyomo.contrib.solver.util import assert_optimal_termination
+   from pyomo.__future__ import solver_factory_v3
+
+   model = pyo.ConcreteModel()
+   model.x = pyo.Var(initialize=1.5)
+   model.y = pyo.Var(initialize=1.5)
+
+   def rosenbrock(model):
+       return (1.0 - model.x) ** 2 + 100.0 * (model.y - model.x**2) ** 2
+
+   model.obj = pyo.Objective(rule=rosenbrock, sense=pyo.minimize)
+
+   status = pyo.SolverFactory('ipopt').solve(model)
+   assert_optimal_termination(status)
+   # Displays important results information; only available through the new interfaces
+   status.display()
+   model.pprint()
+
+.. testoutput::
+   :skipif: not ipopt_available
+   :hide:
+
+   solution_loader: ...
+   ...
+   3 Declarations: x y obj
+
+.. testcode::
+   :skipif: not ipopt_available
+   :hide:
+
+   from pyomo.__future__ import solver_factory_v1
+
+Linear Presolve and Scaling
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The new interface allows access to new capabilities in the various
+problem writers, including the linear presolve and scaling options
+recently incorporated into the redesigned NL writer.  For example, you
+can control the NL writer in the new ``ipopt`` interface through the
+solver's ``writer_config`` configuration option:
+
+.. autoclass:: pyomo.contrib.solver.ipopt.Ipopt
+   :members: solve
+
+.. testcode::
+
+   from pyomo.contrib.solver.ipopt import Ipopt
+   opt = Ipopt()
+   opt.config.writer_config.display()
+
+.. testoutput::
+
+   show_section_timing: false
+   skip_trivial_constraints: true
+   file_determinism: FileDeterminism.ORDERED
+   symbolic_solver_labels: false
+   scale_model: true
+   export_nonlinear_variables: None
+   row_order: None
+   column_order: None
+   export_defined_variables: true
+   linear_presolve: true
+
+Note that, by default, both ``linear_presolve`` and ``scale_model`` are enabled.
+Users can manipulate ``linear_presolve`` and ``scale_model`` to their preferred
+states by changing their values.
+
+.. code-block:: python
+
+   >>> opt.config.writer_config.linear_presolve = False
+
+
+Interface Implementation
+------------------------
+
+All new interfaces should be built upon one of two classes (currently):
+:class:`SolverBase<pyomo.contrib.solver.base.SolverBase>` or
+:class:`PersistentSolverBase<pyomo.contrib.solver.base.PersistentSolverBase>`.
+
+All solvers should have the following:
+
+.. autoclass:: pyomo.contrib.solver.base.SolverBase
+   :members:
+
+Persistent solvers include additional members as well as other configuration options:
+
+.. autoclass:: pyomo.contrib.solver.base.PersistentSolverBase
+   :show-inheritance:
+   :members:
+
+Results
+-------
+
+Every solver, at the end of a
+:meth:`solve<pyomo.contrib.solver.base.SolverBase.solve>` call, will
+return a :class:`Results<pyomo.contrib.solver.results.Results>`
+object.  This object is a :py:class:`pyomo.common.config.ConfigDict`,
+which can be manipulated similar to a standard ``dict`` in Python.
+
+.. autoclass:: pyomo.contrib.solver.results.Results
+   :show-inheritance:
+   :members:
+   :undoc-members:
+
+
+Termination Conditions
+^^^^^^^^^^^^^^^^^^^^^^
+
+Pyomo offers a standard set of termination conditions to map to solver
+returns. The intent of
+:class:`TerminationCondition<pyomo.contrib.solver.results.TerminationCondition>`
+is to notify the user of why the solver exited. The user is expected
+to inspect the :class:`Results<pyomo.contrib.solver.results.Results>`
+object or any returned solver messages or logs for more information.
+
+.. autoclass:: pyomo.contrib.solver.results.TerminationCondition
+   :show-inheritance:
+
+
+Solution Status
+^^^^^^^^^^^^^^^
+
+Pyomo offers a standard set of solution statuses to map to solver
+output. The intent of
+:class:`SolutionStatus<pyomo.contrib.solver.results.SolutionStatus>`
+is to notify the user of what the solver returned at a high level. The
+user is expected to inspect the
+:class:`Results<pyomo.contrib.solver.results.Results>` object or any
+returned solver messages or logs for more information.
+
+.. autoclass:: pyomo.contrib.solver.results.SolutionStatus
+   :show-inheritance:
+
+
+Solution
+--------
+
+Solutions can be loaded back into a model using a ``SolutionLoader``. A specific
+loader should be written for each unique case. Several have already been
+implemented. For example, for ``ipopt``:
+
+.. autoclass:: pyomo.contrib.solver.ipopt.IpoptSolutionLoader
+   :show-inheritance:
+   :members:
+   :inherited-members:
diff --git a/doc/OnlineDocs/installation.rst b/doc/OnlineDocs/installation.rst
index ecba05e13fb..83cd08e7a4a 100644
--- a/doc/OnlineDocs/installation.rst
+++ b/doc/OnlineDocs/installation.rst
@@ -12,7 +12,7 @@ version, Pyomo will remove testing for that Python version.
 Using CONDA
 ~~~~~~~~~~~
 
-We recommend installation with *conda*, which is included with the
+We recommend installation with ``conda``, which is included with the
 Anaconda distribution of Python. You can install Pyomo in your system
 Python installation by executing the following in a shell:
 
@@ -21,7 +21,7 @@ Python installation by executing the following in a shell:
    conda install -c conda-forge pyomo
 
 Optimization solvers are not installed with Pyomo, but some open source
-optimization solvers can be installed with conda as well:
+optimization solvers can be installed with ``conda`` as well:
 
 ::
 
@@ -31,7 +31,7 @@ optimization solvers can be installed with conda as well:
 Using PIP
 ~~~~~~~~~
 
-The standard utility for installing Python packages is *pip*.  You
+The standard utility for installing Python packages is ``pip``.  You
 can install Pyomo in your system Python installation by executing
 the following in a shell:
 
@@ -43,14 +43,14 @@ the following in a shell:
 Conditional Dependencies
 ~~~~~~~~~~~~~~~~~~~~~~~~
 
-Extensions to Pyomo, and many of the contributions in `pyomo.contrib`,
+Extensions to Pyomo, and many of the contributions in ``pyomo.contrib``,
 often have conditional dependencies on a variety of third-party Python
 packages including but not limited to: matplotlib, networkx, numpy,
 openpyxl, pandas, pint, pymysql, pyodbc, pyro4, scipy, sympy, and
 xlrd. 
 
 A full list of conditional dependencies can be found in Pyomo's
-`setup.py` and displayed using:
+``setup.py`` and displayed using:
 
 ::
 
@@ -72,3 +72,28 @@ with the standard Anaconda installation.
 You can check which Python packages you have installed using the command
 ``conda list`` or ``pip list``. Additional Python packages may be
 installed as needed.
+
+
+Installation with Cython
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+Users can opt to install Pyomo with
+`cython <https://cython.readthedocs.io/en/latest/src/tutorial/cython_tutorial.html>`_
+initialized.
+
+.. note::
+   This can only be done via ``pip`` or from source.
+
+Via ``pip``:
+
+::
+
+   pip install pyomo --global-option="--with-cython"
+
+From source (recommended for advanced users only):
+
+::
+
+   git clone https://github.com/Pyomo/pyomo.git
+   cd pyomo
+   python setup.py install --with-cython
diff --git a/doc/OnlineDocs/library_reference/appsi/appsi.solvers.maingo.rst b/doc/OnlineDocs/library_reference/appsi/appsi.solvers.maingo.rst
new file mode 100644
index 00000000000..21e61c38d51
--- /dev/null
+++ b/doc/OnlineDocs/library_reference/appsi/appsi.solvers.maingo.rst
@@ -0,0 +1,14 @@
+MAiNGO
+======
+
+.. autoclass:: pyomo.contrib.appsi.solvers.maingo.MAiNGOConfig
+  :members:
+  :inherited-members:
+  :undoc-members:
+  :show-inheritance:
+
+.. autoclass:: pyomo.contrib.appsi.solvers.maingo.MAiNGO
+  :members:
+  :inherited-members:
+  :undoc-members:
+  :show-inheritance:
diff --git a/doc/OnlineDocs/library_reference/appsi/appsi.solvers.rst b/doc/OnlineDocs/library_reference/appsi/appsi.solvers.rst
index 1c598d95628..f4dcb81b4be 100644
--- a/doc/OnlineDocs/library_reference/appsi/appsi.solvers.rst
+++ b/doc/OnlineDocs/library_reference/appsi/appsi.solvers.rst
@@ -13,3 +13,4 @@ Solvers
    appsi.solvers.cplex
    appsi.solvers.cbc
    appsi.solvers.highs
+   appsi.solvers.maingo
diff --git a/doc/OnlineDocs/library_reference/common/config.rst b/doc/OnlineDocs/library_reference/common/config.rst
index 7a400b26ce3..c5dc607977a 100644
--- a/doc/OnlineDocs/library_reference/common/config.rst
+++ b/doc/OnlineDocs/library_reference/common/config.rst
@@ -36,6 +36,7 @@ Domain validators
    NonPositiveFloat
    NonNegativeFloat
    In
+   IsInstance
    InEnum
    ListOf
    Module
@@ -75,6 +76,7 @@ Domain validators
 .. autofunction:: NonPositiveFloat
 .. autofunction:: NonNegativeFloat
 .. autoclass:: In
+.. autoclass:: IsInstance
 .. autoclass:: InEnum
 .. autoclass:: ListOf
 .. autoclass:: Module
diff --git a/doc/OnlineDocs/library_reference/common/enums.rst b/doc/OnlineDocs/library_reference/common/enums.rst
new file mode 100644
index 00000000000..5ed2dbb1e80
--- /dev/null
+++ b/doc/OnlineDocs/library_reference/common/enums.rst
@@ -0,0 +1,7 @@
+
+pyomo.common.enums
+==================
+
+.. automodule:: pyomo.common.enums
+   :members:
+   :member-order: bysource
diff --git a/doc/OnlineDocs/library_reference/common/index.rst b/doc/OnlineDocs/library_reference/common/index.rst
index c9c99008250..c03436600f2 100644
--- a/doc/OnlineDocs/library_reference/common/index.rst
+++ b/doc/OnlineDocs/library_reference/common/index.rst
@@ -11,6 +11,7 @@ or rely on any other parts of Pyomo.
    config.rst
    dependencies.rst
    deprecation.rst
+   enums.rst
    errors.rst
    fileutils.rst
    formatting.rst
diff --git a/doc/OnlineDocs/library_reference/expressions/context_managers.rst b/doc/OnlineDocs/library_reference/expressions/context_managers.rst
index 0e92f583c73..ae6884d684f 100644
--- a/doc/OnlineDocs/library_reference/expressions/context_managers.rst
+++ b/doc/OnlineDocs/library_reference/expressions/context_managers.rst
@@ -8,6 +8,3 @@ Context Managers
 .. autoclass:: pyomo.core.expr.linear_expression
     :members:
 
-.. autoclass:: pyomo.core.expr.current.clone_counter
-    :members:
-
diff --git a/doc/OnlineDocs/library_reference/kernel/examples/aml_example.py b/doc/OnlineDocs/library_reference/kernel/examples/aml_example.py
index 146048a6046..a640b94cc76 100644
--- a/doc/OnlineDocs/library_reference/kernel/examples/aml_example.py
+++ b/doc/OnlineDocs/library_reference/kernel/examples/aml_example.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # @Import_Syntax
 import pyomo.environ as aml
 
diff --git a/doc/OnlineDocs/library_reference/kernel/examples/conic.py b/doc/OnlineDocs/library_reference/kernel/examples/conic.py
index 9282bc67f9a..0418d188722 100644
--- a/doc/OnlineDocs/library_reference/kernel/examples/conic.py
+++ b/doc/OnlineDocs/library_reference/kernel/examples/conic.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # @Class
 import pyomo.kernel as pmo
 
diff --git a/doc/OnlineDocs/library_reference/kernel/examples/kernel_containers.py b/doc/OnlineDocs/library_reference/kernel/examples/kernel_containers.py
index f2a4ec25ac5..1931c6d9b56 100644
--- a/doc/OnlineDocs/library_reference/kernel/examples/kernel_containers.py
+++ b/doc/OnlineDocs/library_reference/kernel/examples/kernel_containers.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.kernel
 
 # @all
diff --git a/doc/OnlineDocs/library_reference/kernel/examples/kernel_example.py b/doc/OnlineDocs/library_reference/kernel/examples/kernel_example.py
index 1caf064bb2a..1f80bce9788 100644
--- a/doc/OnlineDocs/library_reference/kernel/examples/kernel_example.py
+++ b/doc/OnlineDocs/library_reference/kernel/examples/kernel_example.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # @Import_Syntax
 import pyomo.kernel as pmo
 
diff --git a/doc/OnlineDocs/library_reference/kernel/examples/kernel_solving.py b/doc/OnlineDocs/library_reference/kernel/examples/kernel_solving.py
index 5a8eed9fd89..13d7efc052a 100644
--- a/doc/OnlineDocs/library_reference/kernel/examples/kernel_solving.py
+++ b/doc/OnlineDocs/library_reference/kernel/examples/kernel_solving.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.kernel as pmo
 
 model = pmo.block()
diff --git a/doc/OnlineDocs/library_reference/kernel/examples/kernel_subclassing.py b/doc/OnlineDocs/library_reference/kernel/examples/kernel_subclassing.py
index c21c6dc890b..d6e38f6b0e0 100644
--- a/doc/OnlineDocs/library_reference/kernel/examples/kernel_subclassing.py
+++ b/doc/OnlineDocs/library_reference/kernel/examples/kernel_subclassing.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.kernel
 
 
diff --git a/doc/OnlineDocs/library_reference/kernel/examples/transformer.py b/doc/OnlineDocs/library_reference/kernel/examples/transformer.py
index 66893008cf9..43a1d0675bf 100644
--- a/doc/OnlineDocs/library_reference/kernel/examples/transformer.py
+++ b/doc/OnlineDocs/library_reference/kernel/examples/transformer.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ
 import pyomo.kernel
 
diff --git a/doc/OnlineDocs/modeling_extensions/__init__.py b/doc/OnlineDocs/modeling_extensions/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/doc/OnlineDocs/modeling_extensions/__init__.py
+++ b/doc/OnlineDocs/modeling_extensions/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/doc/OnlineDocs/modeling_extensions/dae.rst b/doc/OnlineDocs/modeling_extensions/dae.rst
index 703e83f4f14..ff0fb75e610 100644
--- a/doc/OnlineDocs/modeling_extensions/dae.rst
+++ b/doc/OnlineDocs/modeling_extensions/dae.rst
@@ -738,7 +738,7 @@ supported by CasADi. A list of available integrators for each package is
 given below. Please refer to the `SciPy
 <https://docs.scipy.org/doc/scipy/reference/generated/scipy.integrate.ode.html>`_
 and `CasADi
-<http://casadi.sourceforge.net/api/html/db/d3d/classcasadi_1_1Integrator.html>`_ documentation directly for the most up-to-date information about
+<https://web.casadi.org/python-api/#integrator>`_ documentation directly for the most up-to-date information about
 these packages and for more information about the various integrators and
 options.
 
diff --git a/doc/OnlineDocs/modeling_extensions/gdp/modeling.rst b/doc/OnlineDocs/modeling_extensions/gdp/modeling.rst
index b70e37d5935..996ebcb0366 100644
--- a/doc/OnlineDocs/modeling_extensions/gdp/modeling.rst
+++ b/doc/OnlineDocs/modeling_extensions/gdp/modeling.rst
@@ -166,7 +166,7 @@ Usage:
     >>> TransformationFactory('core.logical_to_linear').apply_to(m)
     >>> # constraint auto-generated by transformation
     >>> m.logic_to_linear.transformed_constraints.pprint()
-    transformed_constraints : Size=1, Index=logic_to_linear.transformed_constraints_index, Active=True
+    transformed_constraints : Size=1, Index={1}, Active=True
         Key : Lower : Body                                                          : Upper : Active
           1 :   3.0 : Y_asbinary[1] + Y_asbinary[2] + Y_asbinary[3] + Y_asbinary[4] :  +Inf :   True
 
diff --git a/doc/OnlineDocs/modeling_extensions/gdp/solving.rst b/doc/OnlineDocs/modeling_extensions/gdp/solving.rst
index 2f3076862e6..9fea90ebf5f 100644
--- a/doc/OnlineDocs/modeling_extensions/gdp/solving.rst
+++ b/doc/OnlineDocs/modeling_extensions/gdp/solving.rst
@@ -140,6 +140,10 @@ For example, to apply the transformation and store the M values, use:
 
 From the Pyomo command line, include the ``--transform pyomo.gdp.mbigm`` option.
 
+.. warning::
+   The Multiple Big-M transformation does not currently support Suffixes and will
+   ignore "BigM" Suffixes.
+
 Hull Reformulation (HR)
 ^^^^^^^^^^^^^^^^^^^^^^^
 
diff --git a/doc/OnlineDocs/src/data/ABCD1.py b/doc/OnlineDocs/src/data/ABCD1.py
index 32600b226e1..aa2f46e71fa 100644
--- a/doc/OnlineDocs/src/data/ABCD1.py
+++ b/doc/OnlineDocs/src/data/ABCD1.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/ABCD2.py b/doc/OnlineDocs/src/data/ABCD2.py
index 65a46415368..ec0e7ccb15c 100644
--- a/doc/OnlineDocs/src/data/ABCD2.py
+++ b/doc/OnlineDocs/src/data/ABCD2.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/ABCD3.py b/doc/OnlineDocs/src/data/ABCD3.py
index 48797ced5bb..ba55fd970cc 100644
--- a/doc/OnlineDocs/src/data/ABCD3.py
+++ b/doc/OnlineDocs/src/data/ABCD3.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/ABCD4.py b/doc/OnlineDocs/src/data/ABCD4.py
index 20f6a21c011..2fb397aa3b0 100644
--- a/doc/OnlineDocs/src/data/ABCD4.py
+++ b/doc/OnlineDocs/src/data/ABCD4.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/ABCD5.py b/doc/OnlineDocs/src/data/ABCD5.py
index 58461af056b..abc03505e96 100644
--- a/doc/OnlineDocs/src/data/ABCD5.py
+++ b/doc/OnlineDocs/src/data/ABCD5.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/ABCD6.py b/doc/OnlineDocs/src/data/ABCD6.py
index 961408dbc7e..59e0e8e98ae 100644
--- a/doc/OnlineDocs/src/data/ABCD6.py
+++ b/doc/OnlineDocs/src/data/ABCD6.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/ABCD7.py b/doc/OnlineDocs/src/data/ABCD7.py
index a97e764fa5a..1bfb4d1e3fb 100644
--- a/doc/OnlineDocs/src/data/ABCD7.py
+++ b/doc/OnlineDocs/src/data/ABCD7.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 import pyomo.common
 import sys
diff --git a/doc/OnlineDocs/src/data/ABCD8.py b/doc/OnlineDocs/src/data/ABCD8.py
index 9bcd950c681..aa1ba0b4cf5 100644
--- a/doc/OnlineDocs/src/data/ABCD8.py
+++ b/doc/OnlineDocs/src/data/ABCD8.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 import pyomo.common
 import sys
diff --git a/doc/OnlineDocs/src/data/ABCD9.py b/doc/OnlineDocs/src/data/ABCD9.py
index 29fcb6426db..194c71486d9 100644
--- a/doc/OnlineDocs/src/data/ABCD9.py
+++ b/doc/OnlineDocs/src/data/ABCD9.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 import pyomo.common
 import sys
diff --git a/doc/OnlineDocs/src/data/diet1.py b/doc/OnlineDocs/src/data/diet1.py
index ef0d8096350..40582e16ba0 100644
--- a/doc/OnlineDocs/src/data/diet1.py
+++ b/doc/OnlineDocs/src/data/diet1.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # diet1.py
 from pyomo.environ import *
 
diff --git a/doc/OnlineDocs/src/data/ex.py b/doc/OnlineDocs/src/data/ex.py
index 8c9473f2852..a66ee30b494 100644
--- a/doc/OnlineDocs/src/data/ex.py
+++ b/doc/OnlineDocs/src/data/ex.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/import1.tab.py b/doc/OnlineDocs/src/data/import1.tab.py
index c9164ab73ec..e160e4fdcde 100644
--- a/doc/OnlineDocs/src/data/import1.tab.py
+++ b/doc/OnlineDocs/src/data/import1.tab.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/import2.tab.py b/doc/OnlineDocs/src/data/import2.tab.py
index d03f053d090..54339551279 100644
--- a/doc/OnlineDocs/src/data/import2.tab.py
+++ b/doc/OnlineDocs/src/data/import2.tab.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/import3.tab.py b/doc/OnlineDocs/src/data/import3.tab.py
index e86557677ee..664151d1438 100644
--- a/doc/OnlineDocs/src/data/import3.tab.py
+++ b/doc/OnlineDocs/src/data/import3.tab.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/import4.tab.py b/doc/OnlineDocs/src/data/import4.tab.py
index 93df9c761ab..91dd3f26a42 100644
--- a/doc/OnlineDocs/src/data/import4.tab.py
+++ b/doc/OnlineDocs/src/data/import4.tab.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/import5.tab.py b/doc/OnlineDocs/src/data/import5.tab.py
index 1d20476a16f..263677c308c 100644
--- a/doc/OnlineDocs/src/data/import5.tab.py
+++ b/doc/OnlineDocs/src/data/import5.tab.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/import6.tab.py b/doc/OnlineDocs/src/data/import6.tab.py
index 8a1ab232f86..8f4824ad3fe 100644
--- a/doc/OnlineDocs/src/data/import6.tab.py
+++ b/doc/OnlineDocs/src/data/import6.tab.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/import7.tab.py b/doc/OnlineDocs/src/data/import7.tab.py
index 747d884be31..503f9224323 100644
--- a/doc/OnlineDocs/src/data/import7.tab.py
+++ b/doc/OnlineDocs/src/data/import7.tab.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/import8.tab.py b/doc/OnlineDocs/src/data/import8.tab.py
index b7866d7a3e5..02b8724fe45 100644
--- a/doc/OnlineDocs/src/data/import8.tab.py
+++ b/doc/OnlineDocs/src/data/import8.tab.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/param1.py b/doc/OnlineDocs/src/data/param1.py
index c4bc8de5acc..336a04287b9 100644
--- a/doc/OnlineDocs/src/data/param1.py
+++ b/doc/OnlineDocs/src/data/param1.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/param2.py b/doc/OnlineDocs/src/data/param2.py
index f46f05ceebc..a7d0feafff9 100644
--- a/doc/OnlineDocs/src/data/param2.py
+++ b/doc/OnlineDocs/src/data/param2.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/param2a.py b/doc/OnlineDocs/src/data/param2a.py
index 4557f63d841..42056793ffd 100644
--- a/doc/OnlineDocs/src/data/param2a.py
+++ b/doc/OnlineDocs/src/data/param2a.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/param3.py b/doc/OnlineDocs/src/data/param3.py
index 149155ce67d..952f9a9b707 100644
--- a/doc/OnlineDocs/src/data/param3.py
+++ b/doc/OnlineDocs/src/data/param3.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/param3a.py b/doc/OnlineDocs/src/data/param3a.py
index 0e99cad0c7a..028e1d07296 100644
--- a/doc/OnlineDocs/src/data/param3a.py
+++ b/doc/OnlineDocs/src/data/param3a.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/param3b.py b/doc/OnlineDocs/src/data/param3b.py
index deda175ea12..97f8598610a 100644
--- a/doc/OnlineDocs/src/data/param3b.py
+++ b/doc/OnlineDocs/src/data/param3b.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/param3c.py b/doc/OnlineDocs/src/data/param3c.py
index 4056dc8107d..582b0f7db75 100644
--- a/doc/OnlineDocs/src/data/param3c.py
+++ b/doc/OnlineDocs/src/data/param3c.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/param4.py b/doc/OnlineDocs/src/data/param4.py
index 1190dae8dec..010c46fc9c5 100644
--- a/doc/OnlineDocs/src/data/param4.py
+++ b/doc/OnlineDocs/src/data/param4.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/param5.py b/doc/OnlineDocs/src/data/param5.py
index 69f6cc46552..2db07f3f990 100644
--- a/doc/OnlineDocs/src/data/param5.py
+++ b/doc/OnlineDocs/src/data/param5.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/param5a.py b/doc/OnlineDocs/src/data/param5a.py
index 303b92f9f2e..32a53d24e9b 100644
--- a/doc/OnlineDocs/src/data/param5a.py
+++ b/doc/OnlineDocs/src/data/param5a.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/param6.py b/doc/OnlineDocs/src/data/param6.py
index c3e4b25d144..e3364a933cf 100644
--- a/doc/OnlineDocs/src/data/param6.py
+++ b/doc/OnlineDocs/src/data/param6.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/param6a.py b/doc/OnlineDocs/src/data/param6a.py
index 07e8280cc18..3d2fa645411 100644
--- a/doc/OnlineDocs/src/data/param6a.py
+++ b/doc/OnlineDocs/src/data/param6a.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/param7a.py b/doc/OnlineDocs/src/data/param7a.py
index 3bb68b3f3b7..b3aba9ec23d 100644
--- a/doc/OnlineDocs/src/data/param7a.py
+++ b/doc/OnlineDocs/src/data/param7a.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/param7b.py b/doc/OnlineDocs/src/data/param7b.py
index 6e5c857851f..8b022f399a8 100644
--- a/doc/OnlineDocs/src/data/param7b.py
+++ b/doc/OnlineDocs/src/data/param7b.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/param8a.py b/doc/OnlineDocs/src/data/param8a.py
index 57c9b08ca43..abfa885ded4 100644
--- a/doc/OnlineDocs/src/data/param8a.py
+++ b/doc/OnlineDocs/src/data/param8a.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/set1.py b/doc/OnlineDocs/src/data/set1.py
index 5248e9d5dc9..c84c1ef0819 100644
--- a/doc/OnlineDocs/src/data/set1.py
+++ b/doc/OnlineDocs/src/data/set1.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/set2.py b/doc/OnlineDocs/src/data/set2.py
index 82772f48e46..9048a49fecb 100644
--- a/doc/OnlineDocs/src/data/set2.py
+++ b/doc/OnlineDocs/src/data/set2.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/set2a.py b/doc/OnlineDocs/src/data/set2a.py
index edf28757f96..f2fa4d71916 100644
--- a/doc/OnlineDocs/src/data/set2a.py
+++ b/doc/OnlineDocs/src/data/set2a.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/set3.py b/doc/OnlineDocs/src/data/set3.py
index d58e0c0dd43..9cdacbe39e0 100644
--- a/doc/OnlineDocs/src/data/set3.py
+++ b/doc/OnlineDocs/src/data/set3.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/set4.py b/doc/OnlineDocs/src/data/set4.py
index 29548519571..b3485638c6f 100644
--- a/doc/OnlineDocs/src/data/set4.py
+++ b/doc/OnlineDocs/src/data/set4.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/set5.py b/doc/OnlineDocs/src/data/set5.py
index 35acd4e4317..d745d8408d0 100644
--- a/doc/OnlineDocs/src/data/set5.py
+++ b/doc/OnlineDocs/src/data/set5.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/table0.py b/doc/OnlineDocs/src/data/table0.py
index af7f634bd34..de0fae0c861 100644
--- a/doc/OnlineDocs/src/data/table0.py
+++ b/doc/OnlineDocs/src/data/table0.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/table0.ul.py b/doc/OnlineDocs/src/data/table0.ul.py
index 213407b071c..524c3756782 100644
--- a/doc/OnlineDocs/src/data/table0.ul.py
+++ b/doc/OnlineDocs/src/data/table0.ul.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/table1.py b/doc/OnlineDocs/src/data/table1.py
index 1f86508c60a..f36714b8f1f 100644
--- a/doc/OnlineDocs/src/data/table1.py
+++ b/doc/OnlineDocs/src/data/table1.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/table2.py b/doc/OnlineDocs/src/data/table2.py
index d7708b9277f..03648a00f8c 100644
--- a/doc/OnlineDocs/src/data/table2.py
+++ b/doc/OnlineDocs/src/data/table2.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/table2.txt b/doc/OnlineDocs/src/data/table2.txt
index 60eb55aab4a..a710b6b6042 100644
--- a/doc/OnlineDocs/src/data/table2.txt
+++ b/doc/OnlineDocs/src/data/table2.txt
@@ -1,13 +1,10 @@
-3 Set Declarations
+2 Set Declarations
     A : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    3 : {'A1', 'A2', 'A3'}
     B : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    3 : {'B1', 'B2', 'B3'}
-    N_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    A*B :    9 : {('A1', 'B1'), ('A1', 'B2'), ('A1', 'B3'), ('A2', 'B1'), ('A2', 'B2'), ('A2', 'B3'), ('A3', 'B1'), ('A3', 'B2'), ('A3', 'B3')}
 
 2 Param Declarations
     M : Size=3, Index=A, Domain=Any, Default=None, Mutable=False
@@ -15,10 +12,10 @@
          A1 :   4.3
          A2 :   4.4
          A3 :   4.5
-    N : Size=3, Index=N_index, Domain=Any, Default=None, Mutable=False
+    N : Size=3, Index=A*B, Domain=Any, Default=None, Mutable=False
         Key          : Value
         ('A1', 'B1') :   5.3
         ('A2', 'B2') :   5.4
         ('A3', 'B3') :   5.5
 
-5 Declarations: A B M N_index N
+4 Declarations: A B M N
diff --git a/doc/OnlineDocs/src/data/table3.py b/doc/OnlineDocs/src/data/table3.py
index fa871a4f79c..2c598f112df 100644
--- a/doc/OnlineDocs/src/data/table3.py
+++ b/doc/OnlineDocs/src/data/table3.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/table3.txt b/doc/OnlineDocs/src/data/table3.txt
index cb5e63b30d4..c0c61cd5a5b 100644
--- a/doc/OnlineDocs/src/data/table3.txt
+++ b/doc/OnlineDocs/src/data/table3.txt
@@ -1,13 +1,10 @@
-4 Set Declarations
+3 Set Declarations
     A : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    3 : {'A1', 'A2', 'A3'}
     B : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    3 : {'B1', 'B2', 'B3'}
-    N_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    A*B :    9 : {('A1', 'B1'), ('A1', 'B2'), ('A1', 'B3'), ('A2', 'B1'), ('A2', 'B2'), ('A2', 'B3'), ('A3', 'B1'), ('A3', 'B2'), ('A3', 'B3')}
     Z : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     2 :    Any :    3 : {('A1', 'B1'), ('A2', 'B2'), ('A3', 'B3')}
@@ -18,10 +15,10 @@
          A1 :   4.3
          A2 :   4.4
          A3 :   4.5
-    N : Size=3, Index=N_index, Domain=Any, Default=None, Mutable=False
+    N : Size=3, Index=A*B, Domain=Any, Default=None, Mutable=False
         Key          : Value
         ('A1', 'B1') :   5.3
         ('A2', 'B2') :   5.4
         ('A3', 'B3') :   5.5
 
-6 Declarations: A B Z M N_index N
+5 Declarations: A B Z M N
diff --git a/doc/OnlineDocs/src/data/table3.ul.py b/doc/OnlineDocs/src/data/table3.ul.py
index 713d36b9f3a..18ced12b388 100644
--- a/doc/OnlineDocs/src/data/table3.ul.py
+++ b/doc/OnlineDocs/src/data/table3.ul.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/table3.ul.txt b/doc/OnlineDocs/src/data/table3.ul.txt
index cb5e63b30d4..c0c61cd5a5b 100644
--- a/doc/OnlineDocs/src/data/table3.ul.txt
+++ b/doc/OnlineDocs/src/data/table3.ul.txt
@@ -1,13 +1,10 @@
-4 Set Declarations
+3 Set Declarations
     A : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    3 : {'A1', 'A2', 'A3'}
     B : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    3 : {'B1', 'B2', 'B3'}
-    N_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    A*B :    9 : {('A1', 'B1'), ('A1', 'B2'), ('A1', 'B3'), ('A2', 'B1'), ('A2', 'B2'), ('A2', 'B3'), ('A3', 'B1'), ('A3', 'B2'), ('A3', 'B3')}
     Z : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     2 :    Any :    3 : {('A1', 'B1'), ('A2', 'B2'), ('A3', 'B3')}
@@ -18,10 +15,10 @@
          A1 :   4.3
          A2 :   4.4
          A3 :   4.5
-    N : Size=3, Index=N_index, Domain=Any, Default=None, Mutable=False
+    N : Size=3, Index=A*B, Domain=Any, Default=None, Mutable=False
         Key          : Value
         ('A1', 'B1') :   5.3
         ('A2', 'B2') :   5.4
         ('A3', 'B3') :   5.5
 
-6 Declarations: A B Z M N_index N
+5 Declarations: A B Z M N
diff --git a/doc/OnlineDocs/src/data/table4.py b/doc/OnlineDocs/src/data/table4.py
index 1af9fe47a44..bd20682b5a9 100644
--- a/doc/OnlineDocs/src/data/table4.py
+++ b/doc/OnlineDocs/src/data/table4.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/table4.ul.py b/doc/OnlineDocs/src/data/table4.ul.py
index 2acf8e21ca8..9f16f21fe19 100644
--- a/doc/OnlineDocs/src/data/table4.ul.py
+++ b/doc/OnlineDocs/src/data/table4.ul.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/table5.py b/doc/OnlineDocs/src/data/table5.py
index 2fe3d08fe91..a3cb01209a2 100644
--- a/doc/OnlineDocs/src/data/table5.py
+++ b/doc/OnlineDocs/src/data/table5.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/table6.py b/doc/OnlineDocs/src/data/table6.py
index fcbc2f10860..1db0a764a23 100644
--- a/doc/OnlineDocs/src/data/table6.py
+++ b/doc/OnlineDocs/src/data/table6.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/data/table7.py b/doc/OnlineDocs/src/data/table7.py
index f8f8e769b2e..84a841aca86 100644
--- a/doc/OnlineDocs/src/data/table7.py
+++ b/doc/OnlineDocs/src/data/table7.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/dataportal/PP_sqlite.py b/doc/OnlineDocs/src/dataportal/PP_sqlite.py
index 9c6fc5ddc0b..1592e820900 100644
--- a/doc/OnlineDocs/src/dataportal/PP_sqlite.py
+++ b/doc/OnlineDocs/src/dataportal/PP_sqlite.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/doc/OnlineDocs/src/dataportal/dataportal_tab.py b/doc/OnlineDocs/src/dataportal/dataportal_tab.py
index d1a75196c99..655329d31de 100644
--- a/doc/OnlineDocs/src/dataportal/dataportal_tab.py
+++ b/doc/OnlineDocs/src/dataportal/dataportal_tab.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 # --------------------------------------------------
diff --git a/doc/OnlineDocs/src/dataportal/dataportal_tab.txt b/doc/OnlineDocs/src/dataportal/dataportal_tab.txt
index 2e507971157..a23c63d90c9 100644
--- a/doc/OnlineDocs/src/dataportal/dataportal_tab.txt
+++ b/doc/OnlineDocs/src/dataportal/dataportal_tab.txt
@@ -85,19 +85,16 @@
          A3 :   4.5
 
 2 Declarations: A w
-3 Set Declarations
+2 Set Declarations
     A : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    3 : {'A1', 'A2', 'A3'}
     I : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    4 : {'I1', 'I2', 'I3', 'I4'}
-    u_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    I*A :   12 : {('I1', 'A1'), ('I1', 'A2'), ('I1', 'A3'), ('I2', 'A1'), ('I2', 'A2'), ('I2', 'A3'), ('I3', 'A1'), ('I3', 'A2'), ('I3', 'A3'), ('I4', 'A1'), ('I4', 'A2'), ('I4', 'A3')}
 
 1 Param Declarations
-    u : Size=12, Index=u_index, Domain=Any, Default=None, Mutable=False
+    u : Size=12, Index=I*A, Domain=Any, Default=None, Mutable=False
         Key          : Value
         ('I1', 'A1') :   1.3
         ('I1', 'A2') :   2.3
@@ -112,20 +109,17 @@
         ('I4', 'A2') :   2.6
         ('I4', 'A3') :   3.6
 
-4 Declarations: A I u_index u
-3 Set Declarations
+3 Declarations: A I u
+2 Set Declarations
     A : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    3 : {'A1', 'A2', 'A3'}
     I : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    4 : {'I1', 'I2', 'I3', 'I4'}
-    t_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    A*I :   12 : {('A1', 'I1'), ('A1', 'I2'), ('A1', 'I3'), ('A1', 'I4'), ('A2', 'I1'), ('A2', 'I2'), ('A2', 'I3'), ('A2', 'I4'), ('A3', 'I1'), ('A3', 'I2'), ('A3', 'I3'), ('A3', 'I4')}
 
 1 Param Declarations
-    t : Size=12, Index=t_index, Domain=Any, Default=None, Mutable=False
+    t : Size=12, Index=A*I, Domain=Any, Default=None, Mutable=False
         Key          : Value
         ('A1', 'I1') :   1.3
         ('A1', 'I2') :   1.4
@@ -140,7 +134,7 @@
         ('A3', 'I3') :   3.5
         ('A3', 'I4') :   3.6
 
-4 Declarations: A I t_index t
+3 Declarations: A I t
 1 Set Declarations
     A : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
@@ -185,13 +179,9 @@
         None :     1 :    Any :    3 : {'A1', 'A2', 'A3'}
 
 1 Declarations: A
-1 Set Declarations
-    y_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    3 : {'A1', 'A2', 'A3'}
 
 2 Param Declarations
-    y : Size=3, Index=y_index, Domain=Any, Default=None, Mutable=False
+    y : Size=3, Index={A1, A2, A3}, Domain=Any, Default=None, Mutable=False
         Key : Value
          A1 :   3.3
          A2 :   3.4
@@ -200,7 +190,7 @@
         Key  : Value
         None :   1.1
 
-3 Declarations: z y_index y
+2 Declarations: z y
 ['A1', 'A2', 'A3']
 1.1
 A1 3.3
diff --git a/doc/OnlineDocs/src/dataportal/param_initialization.py b/doc/OnlineDocs/src/dataportal/param_initialization.py
index 5567b01f284..7f9270b5fda 100644
--- a/doc/OnlineDocs/src/dataportal/param_initialization.py
+++ b/doc/OnlineDocs/src/dataportal/param_initialization.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 import numpy
 
diff --git a/doc/OnlineDocs/src/dataportal/param_initialization.txt b/doc/OnlineDocs/src/dataportal/param_initialization.txt
index fec8a06a84a..49ea105f120 100644
--- a/doc/OnlineDocs/src/dataportal/param_initialization.txt
+++ b/doc/OnlineDocs/src/dataportal/param_initialization.txt
@@ -1,24 +1,16 @@
-2 Set Declarations
-    b_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    3 : {1, 2, 3}
-    c_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    3 : {1, 2, 3}
-
 3 Param Declarations
     a : Size=1, Index=None, Domain=Any, Default=None, Mutable=False
         Key  : Value
         None :   1.1
-    b : Size=3, Index=b_index, Domain=Any, Default=None, Mutable=False
+    b : Size=3, Index={1, 2, 3}, Domain=Any, Default=None, Mutable=False
         Key : Value
           1 :     1
           2 :     2
           3 :     3
-    c : Size=3, Index=c_index, Domain=Any, Default=None, Mutable=False
+    c : Size=3, Index={1, 2, 3}, Domain=Any, Default=None, Mutable=False
         Key : Value
           1 :     1
           2 :     2
           3 :     3
 
-5 Declarations: a b_index b c_index c
+3 Declarations: a b c
diff --git a/doc/OnlineDocs/src/dataportal/set_initialization.py b/doc/OnlineDocs/src/dataportal/set_initialization.py
index aa7b426fa82..a5ab03894e3 100644
--- a/doc/OnlineDocs/src/dataportal/set_initialization.py
+++ b/doc/OnlineDocs/src/dataportal/set_initialization.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 import numpy
 
diff --git a/doc/OnlineDocs/src/dataportal/set_initialization.txt b/doc/OnlineDocs/src/dataportal/set_initialization.txt
index c6be448eba9..3c2960ce4ef 100644
--- a/doc/OnlineDocs/src/dataportal/set_initialization.txt
+++ b/doc/OnlineDocs/src/dataportal/set_initialization.txt
@@ -1,6 +1,6 @@
 WARNING: Initializing ordered Set B with a fundamentally unordered data source
 (type: set).  This WILL potentially lead to nondeterministic behavior in Pyomo
-9 Set Declarations
+8 Set Declarations
     A : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    3 : {2, 3, 5}
@@ -22,13 +22,10 @@ WARNING: Initializing ordered Set B with a fundamentally unordered data source
     G : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    3 : {2, 3, 5}
-    H : Size=3, Index=H_index, Ordered=Insertion
+    H : Size=3, Index={2, 3, 4}, Ordered=Insertion
         Key : Dimen : Domain : Size : Members
           2 :     1 :    Any :    3 : {1, 3, 5}
           3 :     1 :    Any :    3 : {2, 4, 6}
           4 :     1 :    Any :    3 : {3, 5, 7}
-    H_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    3 : {2, 3, 4}
 
-9 Declarations: A B C D E F G H_index H
+8 Declarations: A B C D E F G H
diff --git a/doc/OnlineDocs/src/expr/design.py b/doc/OnlineDocs/src/expr/design.py
index b122a5f2bf3..647a4537ca4 100644
--- a/doc/OnlineDocs/src/expr/design.py
+++ b/doc/OnlineDocs/src/expr/design.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 # ---------------------------------------------
diff --git a/doc/OnlineDocs/src/expr/index.py b/doc/OnlineDocs/src/expr/index.py
index 9c9c79bf7be..fe5b03461c0 100644
--- a/doc/OnlineDocs/src/expr/index.py
+++ b/doc/OnlineDocs/src/expr/index.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 # ---------------------------------------------
diff --git a/doc/OnlineDocs/src/expr/managing.py b/doc/OnlineDocs/src/expr/managing.py
index 0a59c13bc1b..ff149e4fd5c 100644
--- a/doc/OnlineDocs/src/expr/managing.py
+++ b/doc/OnlineDocs/src/expr/managing.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 from math import isclose
 import math
@@ -170,7 +181,7 @@ def clone_expression(expr):
 # x[0] + 5*x[1]
 print(str(ce))
 # x[0] + 5*x[1]
-print(e.arg(0) is not ce.arg(0))
+print(e.arg(0) is ce.arg(0))
 # True
 print(e.arg(1) is not ce.arg(1))
 # True
diff --git a/doc/OnlineDocs/src/expr/overview.py b/doc/OnlineDocs/src/expr/overview.py
index 6207a4c4288..d33725edb88 100644
--- a/doc/OnlineDocs/src/expr/overview.py
+++ b/doc/OnlineDocs/src/expr/overview.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 # ---------------------------------------------
diff --git a/doc/OnlineDocs/src/expr/performance.py b/doc/OnlineDocs/src/expr/performance.py
index 53ac5bb4f9e..8936bd2ed8c 100644
--- a/doc/OnlineDocs/src/expr/performance.py
+++ b/doc/OnlineDocs/src/expr/performance.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 # ---------------------------------------------
diff --git a/doc/OnlineDocs/src/expr/quicksum.py b/doc/OnlineDocs/src/expr/quicksum.py
index a1ad9660664..1b6cd3f9909 100644
--- a/doc/OnlineDocs/src/expr/quicksum.py
+++ b/doc/OnlineDocs/src/expr/quicksum.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 from pyomo.repn import generate_standard_repn
 import time
diff --git a/doc/OnlineDocs/src/kernel/examples.txt b/doc/OnlineDocs/src/kernel/examples.txt
index e85c64efd86..8ba072d28b1 100644
--- a/doc/OnlineDocs/src/kernel/examples.txt
+++ b/doc/OnlineDocs/src/kernel/examples.txt
@@ -1,22 +1,7 @@
-6 Set Declarations
-    cd_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    s*q :    6 : {(1, 1), (1, 2), (1, 3), (2, 1), (2, 2), (2, 3)}
-    cl_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    3 : {1, 2, 3}
-    ol_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    3 : {1, 2, 3}
+1 Set Declarations
     s : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    2 : {1, 2}
-    sd_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    2 : {1, 2}
-    vl_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    3 : {1, 2, 3}
 
 1 RangeSet Declarations
     q : Dimen=1, Size=3, Bounds=(1, 3)
@@ -43,7 +28,7 @@
         Key : Lower : Value : Upper : Fixed : Stale : Domain
           1 :  None :  None :     9 : False :  True :  Reals
           2 :  None :  None :     9 : False :  True :  Reals
-    vl : Size=3, Index=vl_index
+    vl : Size=3, Index={1, 2, 3}
         Key : Lower : Value : Upper : Fixed : Stale : Domain
           1 :     1 :  None :  None : False :  True :  Reals
           2 :     2 :  None :  None : False :  True :  Reals
@@ -66,7 +51,7 @@
         Key : Active : Sense    : Expression
           1 :   True : minimize : - vd[1]
           2 :   True : minimize : - vd[2]
-    ol : Size=3, Index=ol_index, Active=True
+    ol : Size=3, Index={1, 2, 3}, Active=True
         Key : Active : Sense    : Expression
           1 :   True : minimize : - vl[1]
           2 :   True : minimize : - vl[2]
@@ -76,7 +61,7 @@
     c : Size=1, Index=None, Active=True
         Key  : Lower : Body          : Upper : Active
         None :  -Inf : vd[1] + vd[2] :   9.0 :   True
-    cd : Size=6, Index=cd_index, Active=True
+    cd : Size=6, Index=s*q, Active=True
         Key    : Lower : Body  : Upper : Active
         (1, 1) :   1.0 : vd[1] :   1.0 :   True
         (1, 2) :   2.0 : vd[1] :   2.0 :   True
@@ -84,14 +69,14 @@
         (2, 1) :   1.0 : vd[2] :   1.0 :   True
         (2, 2) :   2.0 : vd[2] :   2.0 :   True
         (2, 3) :   3.0 : vd[2] :   3.0 :   True
-    cl : Size=3, Index=cl_index, Active=True
+    cl : Size=3, Index={1, 2, 3}, Active=True
         Key : Lower : Body      : Upper : Active
           1 :  -5.0 : vl[1] - v :   5.0 :   True
           2 :  -5.0 : vl[2] - v :   5.0 :   True
           3 :  -5.0 : vl[3] - v :   5.0 :   True
 
 3 SOSConstraint Declarations
-       sd : 	Size=2 	Index= sd_index
+       sd : 	Size=2 	Index= OrderedScalarSet
     	1
     		Type=1
     		Weight : Variable
@@ -119,16 +104,8 @@
     b : Size=1, Index=None, Active=True
         0 Declarations: 
     pw : Size=1, Index=None, Active=True
-        2 Set Declarations
-            SOS2_constraint_index : Size=1, Index=None, Ordered=Insertion
-                Key  : Dimen : Domain : Size : Members
-                None :     1 :    Any :    3 : {1, 2, 3}
-            SOS2_y_index : Size=1, Index=None, Ordered=Insertion
-                Key  : Dimen : Domain : Size : Members
-                None :     1 :    Any :    4 : {0, 1, 2, 3}
-
         1 Var Declarations
-            SOS2_y : Size=4, Index=pw.SOS2_y_index
+            SOS2_y : Size=4, Index={0, 1, 2, 3}
                 Key : Lower : Value : Upper : Fixed : Stale : Domain
                   0 :     0 :  None :  None : False :  True : NonNegativeReals
                   1 :     0 :  None :  None : False :  True : NonNegativeReals
@@ -136,7 +113,7 @@
                   3 :     0 :  None :  None : False :  True : NonNegativeReals
 
         1 Constraint Declarations
-            SOS2_constraint : Size=3, Index=pw.SOS2_constraint_index, Active=True
+            SOS2_constraint : Size=3, Index={1, 2, 3}, Active=True
                 Key : Lower : Body                                                                  : Upper : Active
                   1 :   0.0 : v - (pw.SOS2_y[0] + 2*pw.SOS2_y[1] + 3*pw.SOS2_y[2] + 4*pw.SOS2_y[3]) :   0.0 :   True
                   2 :   0.0 :   f - (pw.SOS2_y[0] + 2*pw.SOS2_y[1] + pw.SOS2_y[2] + 2*pw.SOS2_y[3]) :   0.0 :   True
@@ -151,13 +128,13 @@
             		3 : pw.SOS2_y[2]
             		4 : pw.SOS2_y[3]
 
-        5 Declarations: SOS2_y_index SOS2_y SOS2_constraint_index SOS2_constraint SOS2_sosconstraint
+        3 Declarations: SOS2_y SOS2_constraint SOS2_sosconstraint
 
 1 Suffix Declarations
     dual : Direction=IMPORT, Datatype=FLOAT
         Key : Value
 
-27 Declarations: b s q p pd v vd vl_index vl c cd_index cd cl_index cl e ed o od ol_index ol sos1 sos2 sd_index sd dual f pw
+22 Declarations: b s q p pd v vd vl c cd cl e ed o od ol sos1 sos2 sd dual f pw
 <block>: block(active=True, ctype=IBlock)
   - b: block(active=True, ctype=IBlock)
   - p: parameter(active=True, value=0)
@@ -231,4 +208,4 @@
     - pw.c[2]: linear_constraint(active=True, expr=pw.v[0] + pw.v[1] + pw.v[2] + pw.v[3]  ==  1)
    - pw.s: sos(active=True, level=2, entries=['(pw.v[0],1)', '(pw.v[1],2)', '(pw.v[2],3)', '(pw.v[3],4)'])
 Memory: 1.9 KB
-Memory: 9.5 KB
+Memory: 9.7 KB
diff --git a/doc/OnlineDocs/src/scripting/AbstractSuffixes.py b/doc/OnlineDocs/src/scripting/AbstractSuffixes.py
index 20a4cc20581..1c064042c6b 100644
--- a/doc/OnlineDocs/src/scripting/AbstractSuffixes.py
+++ b/doc/OnlineDocs/src/scripting/AbstractSuffixes.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/doc/OnlineDocs/src/scripting/Isinglebuild.py b/doc/OnlineDocs/src/scripting/Isinglebuild.py
index 00f79c9a750..344f8905a4a 100644
--- a/doc/OnlineDocs/src/scripting/Isinglebuild.py
+++ b/doc/OnlineDocs/src/scripting/Isinglebuild.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # Isinglebuild.py
 # NodesIn and NodesOut are created by a build action using the Arcs
 from pyomo.environ import *
diff --git a/doc/OnlineDocs/src/scripting/NodesIn_init.py b/doc/OnlineDocs/src/scripting/NodesIn_init.py
index 4a90029baa3..c17b70150bc 100644
--- a/doc/OnlineDocs/src/scripting/NodesIn_init.py
+++ b/doc/OnlineDocs/src/scripting/NodesIn_init.py
@@ -1,3 +1,15 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+
 def NodesIn_init(model, node):
     retval = []
     for i, j in model.Arcs:
diff --git a/doc/OnlineDocs/src/scripting/Z_init.py b/doc/OnlineDocs/src/scripting/Z_init.py
index 426de6f7d08..1dd2843f4f0 100644
--- a/doc/OnlineDocs/src/scripting/Z_init.py
+++ b/doc/OnlineDocs/src/scripting/Z_init.py
@@ -1,3 +1,15 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+
 def Z_init(model, i):
     if i > 10:
         return Set.End
diff --git a/doc/OnlineDocs/src/scripting/abstract2.py b/doc/OnlineDocs/src/scripting/abstract2.py
index 1e14d1d1898..544399a8a42 100644
--- a/doc/OnlineDocs/src/scripting/abstract2.py
+++ b/doc/OnlineDocs/src/scripting/abstract2.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # abstract2.py
 
 
diff --git a/doc/OnlineDocs/src/scripting/abstract2piece.py b/doc/OnlineDocs/src/scripting/abstract2piece.py
index 225ec0d1a64..03c5139004e 100644
--- a/doc/OnlineDocs/src/scripting/abstract2piece.py
+++ b/doc/OnlineDocs/src/scripting/abstract2piece.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # abstract2piece.py
 # Similar to abstract2.py, but the objective is now c times x to the fourth power
 
diff --git a/doc/OnlineDocs/src/scripting/abstract2piecebuild.py b/doc/OnlineDocs/src/scripting/abstract2piecebuild.py
index 1f00cdb0265..d454d7fbc79 100644
--- a/doc/OnlineDocs/src/scripting/abstract2piecebuild.py
+++ b/doc/OnlineDocs/src/scripting/abstract2piecebuild.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # abstract2piecebuild.py
 # Similar to abstract2piece.py, but the breakpoints are created using a build action
 
diff --git a/doc/OnlineDocs/src/scripting/block_iter_example.py b/doc/OnlineDocs/src/scripting/block_iter_example.py
index 680e0d1728b..10c8a4ea43d 100644
--- a/doc/OnlineDocs/src/scripting/block_iter_example.py
+++ b/doc/OnlineDocs/src/scripting/block_iter_example.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # written by jds, adapted for doc by dlw
 from pyomo.environ import *
 
diff --git a/doc/OnlineDocs/src/scripting/concrete1.py b/doc/OnlineDocs/src/scripting/concrete1.py
index 2cd1a1f722c..399715efde6 100644
--- a/doc/OnlineDocs/src/scripting/concrete1.py
+++ b/doc/OnlineDocs/src/scripting/concrete1.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = ConcreteModel()
diff --git a/doc/OnlineDocs/src/scripting/doubleA.py b/doc/OnlineDocs/src/scripting/doubleA.py
index 12a07944db3..abf35979a05 100644
--- a/doc/OnlineDocs/src/scripting/doubleA.py
+++ b/doc/OnlineDocs/src/scripting/doubleA.py
@@ -1,3 +1,15 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+
 def doubleA_init(model):
     return (i * 2 for i in model.A)
 
diff --git a/doc/OnlineDocs/src/scripting/driveabs2.py b/doc/OnlineDocs/src/scripting/driveabs2.py
index 45862195a57..f8f972460b1 100644
--- a/doc/OnlineDocs/src/scripting/driveabs2.py
+++ b/doc/OnlineDocs/src/scripting/driveabs2.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # driveabs2.py
 
 import pyomo.environ as pyo
diff --git a/doc/OnlineDocs/src/scripting/driveconc1.py b/doc/OnlineDocs/src/scripting/driveconc1.py
index 95b0f42806d..49b92f32d09 100644
--- a/doc/OnlineDocs/src/scripting/driveconc1.py
+++ b/doc/OnlineDocs/src/scripting/driveconc1.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # driveconc1.py
 
 import pyomo.environ as pyo
diff --git a/doc/OnlineDocs/src/scripting/iterative1.py b/doc/OnlineDocs/src/scripting/iterative1.py
index 61b0fd3828e..939120e834f 100644
--- a/doc/OnlineDocs/src/scripting/iterative1.py
+++ b/doc/OnlineDocs/src/scripting/iterative1.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # @Import_symbols_for_pyomo
 # iterative1.py
 import pyomo.environ as pyo
diff --git a/doc/OnlineDocs/src/scripting/iterative2.py b/doc/OnlineDocs/src/scripting/iterative2.py
index e559a2c8400..7506337a491 100644
--- a/doc/OnlineDocs/src/scripting/iterative2.py
+++ b/doc/OnlineDocs/src/scripting/iterative2.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # iterative2.py
 
 import pyomo.environ as pyo
diff --git a/doc/OnlineDocs/src/scripting/noiteration1.py b/doc/OnlineDocs/src/scripting/noiteration1.py
index be9fb529855..c7a86e9d1e9 100644
--- a/doc/OnlineDocs/src/scripting/noiteration1.py
+++ b/doc/OnlineDocs/src/scripting/noiteration1.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # noiteration1.py
 
 import pyomo.environ as pyo
diff --git a/doc/OnlineDocs/src/scripting/parallel.py b/doc/OnlineDocs/src/scripting/parallel.py
index cf9b55d9605..e6cfa002780 100644
--- a/doc/OnlineDocs/src/scripting/parallel.py
+++ b/doc/OnlineDocs/src/scripting/parallel.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # parallel.py
 # run with mpirun -np 2 python -m mpi4py parallel.py
 import pyomo.environ as pyo
diff --git a/doc/OnlineDocs/src/scripting/spy4Constraints.py b/doc/OnlineDocs/src/scripting/spy4Constraints.py
index f0033bbc33e..66f82802402 100644
--- a/doc/OnlineDocs/src/scripting/spy4Constraints.py
+++ b/doc/OnlineDocs/src/scripting/spy4Constraints.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """
 David L. Woodruff and Mingye Yang, Spring 2018
 Code snippets for Constraints.rst in testable form
diff --git a/doc/OnlineDocs/src/scripting/spy4Expressions.py b/doc/OnlineDocs/src/scripting/spy4Expressions.py
index 0e8a50c78b3..cf7ed1f112f 100644
--- a/doc/OnlineDocs/src/scripting/spy4Expressions.py
+++ b/doc/OnlineDocs/src/scripting/spy4Expressions.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """
 David L. Woodruff and Mingye Yang, Spring 2018
 Code snippets for Expressions.rst in testable form
diff --git a/doc/OnlineDocs/src/scripting/spy4PyomoCommand.py b/doc/OnlineDocs/src/scripting/spy4PyomoCommand.py
index f655b812076..9f6698d63c9 100644
--- a/doc/OnlineDocs/src/scripting/spy4PyomoCommand.py
+++ b/doc/OnlineDocs/src/scripting/spy4PyomoCommand.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """
 David L. Woodruff and Mingye Yang, Spring 2018
 Code snippets for PyomoCommand.rst in testable form
diff --git a/doc/OnlineDocs/src/scripting/spy4Variables.py b/doc/OnlineDocs/src/scripting/spy4Variables.py
index c4e2ff612f1..1bc2dc9f1ef 100644
--- a/doc/OnlineDocs/src/scripting/spy4Variables.py
+++ b/doc/OnlineDocs/src/scripting/spy4Variables.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """
 David L. Woodruff and Mingye Yang, Spring 2018
 Code snippets for Variables.rst in testable form
diff --git a/doc/OnlineDocs/src/scripting/spy4scripts.py b/doc/OnlineDocs/src/scripting/spy4scripts.py
index 48ba923d09c..f71a1b67b11 100644
--- a/doc/OnlineDocs/src/scripting/spy4scripts.py
+++ b/doc/OnlineDocs/src/scripting/spy4scripts.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 ###NOTE: as of May 16, this will not even come close to running. DLW
 ### and it is "wrong" in a lot of places.
 ### Someone should edit this file, then delete these comment lines. DLW may 16
diff --git a/doc/OnlineDocs/src/strip_examples.py b/doc/OnlineDocs/src/strip_examples.py
index 045af6b87cc..2fd03256499 100644
--- a/doc/OnlineDocs/src/strip_examples.py
+++ b/doc/OnlineDocs/src/strip_examples.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 #
 # This script finds all *.py files in the current and subdirectories.
 # It processes these files to find blocks that start/end with "# @"
diff --git a/doc/OnlineDocs/src/test_examples.py b/doc/OnlineDocs/src/test_examples.py
index a7991eadf19..c5c9a135ee9 100644
--- a/doc/OnlineDocs/src/test_examples.py
+++ b/doc/OnlineDocs/src/test_examples.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/doc/OnlineDocs/tutorial_examples.rst b/doc/OnlineDocs/tutorial_examples.rst
index dc58b6a6f59..a18f9d77d42 100644
--- a/doc/OnlineDocs/tutorial_examples.rst
+++ b/doc/OnlineDocs/tutorial_examples.rst
@@ -3,13 +3,18 @@ Pyomo Tutorial Examples
 
 Additional Pyomo tutorials and examples can be found at the following links:
 
-`Pyomo Workshop Slides and Exercises
-<https://github.com/Pyomo/pyomo-tutorials>`_
+* `Pyomo — Optimization Modeling in Python
+  <https://link.springer.com/book/10.1007/978-3-030-68928-5>`_ ([PyomoBookIII]_)
 
-`Prof. Jeffrey Kantor's Pyomo Cookbook
-<https://jckantor.github.io/ND-Pyomo-Cookbook/>`_
+* `Pyomo Workshop Slides and Exercises
+  <https://github.com/Pyomo/pyomo-tutorials>`_
 
-`Pyomo Gallery
-<https://github.com/Pyomo/PyomoGallery>`_
+* `Prof. Jeffrey Kantor's Pyomo Cookbook
+  <https://jckantor.github.io/ND-Pyomo-Cookbook/>`_
+
+* The `companion notebooks <https://mobook.github.io/MO-book/intro.html>`_
+  for *Hands-On Mathematical Optimization with Python*
+
+* `Pyomo Gallery <https://github.com/Pyomo/PyomoGallery>`_
 
 
diff --git a/doc/OnlineDocs/working_abstractmodels/data/raw_dicts.rst b/doc/OnlineDocs/working_abstractmodels/data/raw_dicts.rst
index e10042b3ceb..f78e349c28b 100644
--- a/doc/OnlineDocs/working_abstractmodels/data/raw_dicts.rst
+++ b/doc/OnlineDocs/working_abstractmodels/data/raw_dicts.rst
@@ -28,13 +28,10 @@ components, the required data dictionary maps the implicit index
     ... }}
     >>> i = m.create_instance(data)
     >>> i.pprint()
-    2 Set Declarations
+    1 Set Declarations
         I : Size=1, Index=None, Ordered=Insertion
             Key  : Dimen : Domain : Size : Members
             None :     1 :    Any :    3 : {1, 2, 3}
-        r_index : Size=1, Index=None, Ordered=True
-            Key  : Dimen : Domain : Size : Members
-            None :     2 :    I*I :    9 : {(1, 1), (1, 2), (1, 3), (2, 1), (2, 2), (2, 3), (3, 1), (3, 2), (3, 3)}
     <BLANKLINE>
     3 Param Declarations
         p : Size=1, Index=None, Domain=Any, Default=None, Mutable=False
@@ -45,12 +42,12 @@ components, the required data dictionary maps the implicit index
               1 :    10
               2 :    20
               3 :    30
-        r : Size=9, Index=r_index, Domain=Any, Default=0, Mutable=False
+        r : Size=9, Index=I*I, Domain=Any, Default=0, Mutable=False
             Key    : Value
             (1, 1) :   110
             (1, 2) :   120
             (2, 3) :   230
     <BLANKLINE>
-    5 Declarations: I p q r_index r
+    4 Declarations: I p q r
 
 
diff --git a/examples/dae/Heat_Conduction.py b/examples/dae/Heat_Conduction.py
index 11f35fddd13..7e11ec59263 100644
--- a/examples/dae/Heat_Conduction.py
+++ b/examples/dae/Heat_Conduction.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/dae/Optimal_Control.py b/examples/dae/Optimal_Control.py
index ed44d5eeb59..676c95271f2 100644
--- a/examples/dae/Optimal_Control.py
+++ b/examples/dae/Optimal_Control.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/dae/PDE_example.py b/examples/dae/PDE_example.py
index 6cb7eb4a7fe..0aea173415b 100644
--- a/examples/dae/PDE_example.py
+++ b/examples/dae/PDE_example.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/dae/Parameter_Estimation.py b/examples/dae/Parameter_Estimation.py
index 7ee2f112b94..332a21d93dc 100644
--- a/examples/dae/Parameter_Estimation.py
+++ b/examples/dae/Parameter_Estimation.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/dae/Path_Constraint.py b/examples/dae/Path_Constraint.py
index 866b4b3b90a..69f31980c63 100644
--- a/examples/dae/Path_Constraint.py
+++ b/examples/dae/Path_Constraint.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/dae/ReactionKinetics.py b/examples/dae/ReactionKinetics.py
index ef760820c4b..2e474ae40d3 100644
--- a/examples/dae/ReactionKinetics.py
+++ b/examples/dae/ReactionKinetics.py
@@ -2,7 +2,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -304,7 +304,10 @@ def regression_model():
 
     # Model & data from:
     #
-    # http://www.doiserbia.nb.rs/img/doi/0367-598X/2014/0367-598X1300037A.pdf
+    # https://doiserbia.nb.rs/img/doi/0367-598X/2014/0367-598X1300037A.pdf
+    # Almagrbi, A. M., Hatami, T., Glišić, S., & Orlović, A. (2014).
+    # Determination of kinetic parameters for complex transesterification
+    # reaction by standard optimisation methods.
     #
     model = ConcreteModel()
 
diff --git a/examples/dae/car_example.py b/examples/dae/car_example.py
index a157159cf6c..b6ca2203860 100644
--- a/examples/dae/car_example.py
+++ b/examples/dae/car_example.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # Ampl Car Example
 #
 # Shows how to convert a minimize final time optimal control problem
diff --git a/examples/dae/disease_DAE.py b/examples/dae/disease_DAE.py
index 59e598aa504..bfeb2530fc9 100644
--- a/examples/dae/disease_DAE.py
+++ b/examples/dae/disease_DAE.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 ###
 # SIR disease model using radau collocation
 ###
diff --git a/examples/dae/distill_DAE.py b/examples/dae/distill_DAE.py
index cdfd543f9a8..e822cfb1752 100644
--- a/examples/dae/distill_DAE.py
+++ b/examples/dae/distill_DAE.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/dae/dynamic_scheduling.py b/examples/dae/dynamic_scheduling.py
index 13cabeb5bcf..137307e31a9 100644
--- a/examples/dae/dynamic_scheduling.py
+++ b/examples/dae/dynamic_scheduling.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/dae/laplace_BVP.py b/examples/dae/laplace_BVP.py
index 6b2e2841575..61f911b3826 100644
--- a/examples/dae/laplace_BVP.py
+++ b/examples/dae/laplace_BVP.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/dae/run_Optimal_Control.py b/examples/dae/run_Optimal_Control.py
index 2523bd8c607..2e7bc79dff4 100644
--- a/examples/dae/run_Optimal_Control.py
+++ b/examples/dae/run_Optimal_Control.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/dae/run_Parameter_Estimation.py b/examples/dae/run_Parameter_Estimation.py
index a319000cb59..c9b649df8dd 100644
--- a/examples/dae/run_Parameter_Estimation.py
+++ b/examples/dae/run_Parameter_Estimation.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/dae/run_Path_Constraint.py b/examples/dae/run_Path_Constraint.py
index 17a576a57d8..996b432a555 100644
--- a/examples/dae/run_Path_Constraint.py
+++ b/examples/dae/run_Path_Constraint.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/dae/run_disease.py b/examples/dae/run_disease.py
index 139046d434e..5d9595a89d5 100644
--- a/examples/dae/run_disease.py
+++ b/examples/dae/run_disease.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 from pyomo.dae import *
 from disease_DAE import model
diff --git a/examples/dae/run_distill.py b/examples/dae/run_distill.py
index d9ececf34fc..9b09850f90a 100644
--- a/examples/dae/run_distill.py
+++ b/examples/dae/run_distill.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/dae/run_stochpdegas_automatic.py b/examples/dae/run_stochpdegas_automatic.py
index dd710588406..6fc9f6d594c 100644
--- a/examples/dae/run_stochpdegas_automatic.py
+++ b/examples/dae/run_stochpdegas_automatic.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import time
 
 from pyomo.environ import *
diff --git a/examples/dae/simulator_dae_example.py b/examples/dae/simulator_dae_example.py
index ef6484be6c6..4ea1f9fd5f0 100644
--- a/examples/dae/simulator_dae_example.py
+++ b/examples/dae/simulator_dae_example.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 #
 # Batch reactor example from Biegler book on Nonlinear Programming Chapter 9
 #
diff --git a/examples/dae/simulator_dae_multindex_example.py b/examples/dae/simulator_dae_multindex_example.py
index d1a97fec79f..775eb4f8c79 100644
--- a/examples/dae/simulator_dae_multindex_example.py
+++ b/examples/dae/simulator_dae_multindex_example.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 #
 # Batch reactor example from Biegler book on Nonlinear Programming Chapter 9
 #
diff --git a/examples/dae/simulator_ode_example.py b/examples/dae/simulator_ode_example.py
index bf600cf163e..f6f28b87d07 100644
--- a/examples/dae/simulator_ode_example.py
+++ b/examples/dae/simulator_ode_example.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 #
 # Example from Scipy odeint examples
 #
diff --git a/examples/dae/simulator_ode_multindex_example.py b/examples/dae/simulator_ode_multindex_example.py
index fa2623f4cc2..b1b9111084b 100644
--- a/examples/dae/simulator_ode_multindex_example.py
+++ b/examples/dae/simulator_ode_multindex_example.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 #
 # Example from Scipy odeint examples
 #
diff --git a/examples/dae/stochpdegas_automatic.py b/examples/dae/stochpdegas_automatic.py
index fdde099a396..397b4a18100 100644
--- a/examples/dae/stochpdegas_automatic.py
+++ b/examples/dae/stochpdegas_automatic.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # stochastic pde model for natural gas network
 # victor m. zavala / 2013
 
diff --git a/examples/doc/samples/__init__.py b/examples/doc/samples/__init__.py
index 3115f06ef53..0110902b288 100644
--- a/examples/doc/samples/__init__.py
+++ b/examples/doc/samples/__init__.py
@@ -1 +1,12 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # Dummy file for pytest
diff --git a/examples/doc/samples/case_studies/deer/DeerProblem.py b/examples/doc/samples/case_studies/deer/DeerProblem.py
index 0b6b7252aaa..d09c9b53887 100644
--- a/examples/doc/samples/case_studies/deer/DeerProblem.py
+++ b/examples/doc/samples/case_studies/deer/DeerProblem.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.core import *
 
 #
diff --git a/examples/doc/samples/case_studies/diet/DietProblem.py b/examples/doc/samples/case_studies/diet/DietProblem.py
index f070201c28e..64624310943 100644
--- a/examples/doc/samples/case_studies/diet/DietProblem.py
+++ b/examples/doc/samples/case_studies/diet/DietProblem.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.core import *
 
 model = AbstractModel()
diff --git a/examples/doc/samples/case_studies/disease_est/DiseaseEstimation.py b/examples/doc/samples/case_studies/disease_est/DiseaseEstimation.py
index c685a6ee67f..6a0edb38350 100644
--- a/examples/doc/samples/case_studies/disease_est/DiseaseEstimation.py
+++ b/examples/doc/samples/case_studies/disease_est/DiseaseEstimation.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.core import *
 
 model = AbstractModel()
diff --git a/examples/doc/samples/case_studies/max_flow/MaxFlow.py b/examples/doc/samples/case_studies/max_flow/MaxFlow.py
index c6eb42ccf7d..1e75fa4e79d 100644
--- a/examples/doc/samples/case_studies/max_flow/MaxFlow.py
+++ b/examples/doc/samples/case_studies/max_flow/MaxFlow.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.core import *
 
 model = AbstractModel()
diff --git a/examples/doc/samples/case_studies/network_flow/networkFlow1.py b/examples/doc/samples/case_studies/network_flow/networkFlow1.py
index adfaab4476b..eb8c8e48a1a 100644
--- a/examples/doc/samples/case_studies/network_flow/networkFlow1.py
+++ b/examples/doc/samples/case_studies/network_flow/networkFlow1.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.core import *
 
 model = AbstractModel()
diff --git a/examples/doc/samples/case_studies/rosen/Rosenbrock.py b/examples/doc/samples/case_studies/rosen/Rosenbrock.py
index 9677cea95dd..51e7d51b57d 100644
--- a/examples/doc/samples/case_studies/rosen/Rosenbrock.py
+++ b/examples/doc/samples/case_studies/rosen/Rosenbrock.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # @intro:
 from pyomo.core import *
 
diff --git a/examples/doc/samples/case_studies/transportation/transportation.py b/examples/doc/samples/case_studies/transportation/transportation.py
index 26fcb5f0b66..588ae764953 100644
--- a/examples/doc/samples/case_studies/transportation/transportation.py
+++ b/examples/doc/samples/case_studies/transportation/transportation.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.core import *
 
 model = AbstractModel()
diff --git a/examples/doc/samples/comparisons/cutstock/cutstock_cplex.py b/examples/doc/samples/comparisons/cutstock/cutstock_cplex.py
index 796c39810f8..f49c5b591ae 100644
--- a/examples/doc/samples/comparisons/cutstock/cutstock_cplex.py
+++ b/examples/doc/samples/comparisons/cutstock/cutstock_cplex.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import cplex
 from cutstock_util import *
 from cplex.exceptions import CplexSolverError
diff --git a/examples/doc/samples/comparisons/cutstock/cutstock_grb.py b/examples/doc/samples/comparisons/cutstock/cutstock_grb.py
index 4fa4556fc96..483d84b02e6 100644
--- a/examples/doc/samples/comparisons/cutstock/cutstock_grb.py
+++ b/examples/doc/samples/comparisons/cutstock/cutstock_grb.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from gurobipy import *
 from cutstock_util import *
 
diff --git a/examples/doc/samples/comparisons/cutstock/cutstock_lpsolve.py b/examples/doc/samples/comparisons/cutstock/cutstock_lpsolve.py
index 658ee006c30..9a6c8301e8f 100644
--- a/examples/doc/samples/comparisons/cutstock/cutstock_lpsolve.py
+++ b/examples/doc/samples/comparisons/cutstock/cutstock_lpsolve.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from lpsolve55 import *
 from cutstock_util import *
 
diff --git a/examples/doc/samples/comparisons/cutstock/cutstock_pulpor.py b/examples/doc/samples/comparisons/cutstock/cutstock_pulpor.py
index 2f2506ba3d6..d14b0fe46c1 100644
--- a/examples/doc/samples/comparisons/cutstock/cutstock_pulpor.py
+++ b/examples/doc/samples/comparisons/cutstock/cutstock_pulpor.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pulp import *
 from cutstock_util import *
 
diff --git a/examples/doc/samples/comparisons/cutstock/cutstock_pyomo.py b/examples/doc/samples/comparisons/cutstock/cutstock_pyomo.py
index a67ebdd0675..48d7e6b26fd 100644
--- a/examples/doc/samples/comparisons/cutstock/cutstock_pyomo.py
+++ b/examples/doc/samples/comparisons/cutstock/cutstock_pyomo.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.core import *
 import pyomo.opt
 from cutstock_util import *
diff --git a/examples/doc/samples/comparisons/cutstock/cutstock_util.py b/examples/doc/samples/comparisons/cutstock/cutstock_util.py
index 1cd8c61922f..da5349ec06c 100644
--- a/examples/doc/samples/comparisons/cutstock/cutstock_util.py
+++ b/examples/doc/samples/comparisons/cutstock/cutstock_util.py
@@ -1,3 +1,15 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+
 def getCutCount():
     cutCount = 0
     fout1 = open('WidthDemand.csv', 'r')
diff --git a/examples/doc/samples/comparisons/sched/pyomo/sched.py b/examples/doc/samples/comparisons/sched/pyomo/sched.py
index 627bc083fbe..cf781713641 100644
--- a/examples/doc/samples/comparisons/sched/pyomo/sched.py
+++ b/examples/doc/samples/comparisons/sched/pyomo/sched.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.core import *
 
 model = AbstractModel()
diff --git a/examples/doc/samples/scripts/__init__.py b/examples/doc/samples/scripts/__init__.py
index 3115f06ef53..0110902b288 100644
--- a/examples/doc/samples/scripts/__init__.py
+++ b/examples/doc/samples/scripts/__init__.py
@@ -1 +1,12 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # Dummy file for pytest
diff --git a/examples/doc/samples/scripts/s1/knapsack.py b/examples/doc/samples/scripts/s1/knapsack.py
index 642e0faaaed..cee3937b668 100644
--- a/examples/doc/samples/scripts/s1/knapsack.py
+++ b/examples/doc/samples/scripts/s1/knapsack.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.core import *
 
 
diff --git a/examples/doc/samples/scripts/s1/script.py b/examples/doc/samples/scripts/s1/script.py
index 02b6b406922..4ddaea45e19 100644
--- a/examples/doc/samples/scripts/s1/script.py
+++ b/examples/doc/samples/scripts/s1/script.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.core import *
 import pyomo.opt
 import pyomo.environ
diff --git a/examples/doc/samples/scripts/s2/knapsack.py b/examples/doc/samples/scripts/s2/knapsack.py
index a7d693f5d35..3131cee7bc5 100644
--- a/examples/doc/samples/scripts/s2/knapsack.py
+++ b/examples/doc/samples/scripts/s2/knapsack.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.core import *
 
 
diff --git a/examples/doc/samples/scripts/s2/script.py b/examples/doc/samples/scripts/s2/script.py
index 88de1dec680..fe97d6ab8fd 100644
--- a/examples/doc/samples/scripts/s2/script.py
+++ b/examples/doc/samples/scripts/s2/script.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.core import *
 import pyomo.opt
 import pyomo.environ
diff --git a/examples/doc/samples/scripts/test_scripts.py b/examples/doc/samples/scripts/test_scripts.py
index ca0c8a7cc4e..691a44aea2d 100644
--- a/examples/doc/samples/scripts/test_scripts.py
+++ b/examples/doc/samples/scripts/test_scripts.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/doc/samples/update.py b/examples/doc/samples/update.py
index 9eae2f4b694..8789413303c 100644
--- a/examples/doc/samples/update.py
+++ b/examples/doc/samples/update.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 #!/usr/bin/env python
 #
 # This is a Python script that regenerates the top-level TRAC.txt file, which
diff --git a/examples/gdp/batchProcessing.py b/examples/gdp/batchProcessing.py
index f0980dd5034..9810f5d63f1 100644
--- a/examples/gdp/batchProcessing.py
+++ b/examples/gdp/batchProcessing.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 from pyomo.gdp import *
 
diff --git a/examples/gdp/circles/circles.py b/examples/gdp/circles/circles.py
index ae905998403..a8b7a156fad 100644
--- a/examples/gdp/circles/circles.py
+++ b/examples/gdp/circles/circles.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """
 The "circles" GDP example problem originating in Lee and Grossman (2000). The 
 goal is to choose a point to minimize a convex quadratic function over a set of 
diff --git a/examples/gdp/constrained_layout/cons_layout_model.py b/examples/gdp/constrained_layout/cons_layout_model.py
index 245aa2df58e..d38fd0cc66b 100644
--- a/examples/gdp/constrained_layout/cons_layout_model.py
+++ b/examples/gdp/constrained_layout/cons_layout_model.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """2-D constrained layout example.
 
 Example based on: https://www.minlp.org/library/problem/index.php?i=107&lib=GDP
diff --git a/examples/gdp/disease_model.py b/examples/gdp/disease_model.py
index bc3e69600ec..498337e35e6 100644
--- a/examples/gdp/disease_model.py
+++ b/examples/gdp/disease_model.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/gdp/eight_process/eight_proc_logical.py b/examples/gdp/eight_process/eight_proc_logical.py
index 60f7acee876..4496427d421 100644
--- a/examples/gdp/eight_process/eight_proc_logical.py
+++ b/examples/gdp/eight_process/eight_proc_logical.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """Disjunctive re-implementation of eight-process problem.
 
 Re-implementation of Duran example 3 superstructure synthesis problem in Pyomo
diff --git a/examples/gdp/eight_process/eight_proc_model.py b/examples/gdp/eight_process/eight_proc_model.py
index 840b6911d83..41bb6d462f1 100644
--- a/examples/gdp/eight_process/eight_proc_model.py
+++ b/examples/gdp/eight_process/eight_proc_model.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """Disjunctive re-implementation of eight-process problem.
 
 Re-implementation of Duran example 3 superstructure synthesis problem in Pyomo
diff --git a/examples/gdp/eight_process/eight_proc_verbose_model.py b/examples/gdp/eight_process/eight_proc_verbose_model.py
index cae584d4127..1fd68909146 100644
--- a/examples/gdp/eight_process/eight_proc_verbose_model.py
+++ b/examples/gdp/eight_process/eight_proc_verbose_model.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """Disjunctive re-implementation of eight-process problem.
 
 This is the more verbose formulation of the same problem given in
diff --git a/examples/gdp/farm_layout/farm_layout.py b/examples/gdp/farm_layout/farm_layout.py
index 411e2de3242..1b232b9cfa6 100644
--- a/examples/gdp/farm_layout/farm_layout.py
+++ b/examples/gdp/farm_layout/farm_layout.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """
 Farm layout example from Sawaya (2006). The goal is to determine optimal placements and dimensions for farm
 plots of specified areas to minimize the perimeter of a minimal enclosing fence. This is a GDP problem with 
diff --git a/examples/gdp/jobshop-nodisjuncts.py b/examples/gdp/jobshop-nodisjuncts.py
index bc656dc4717..0cd5b5ab274 100644
--- a/examples/gdp/jobshop-nodisjuncts.py
+++ b/examples/gdp/jobshop-nodisjuncts.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/gdp/jobshop.py b/examples/gdp/jobshop.py
index 619ece47e72..7119ee7655c 100644
--- a/examples/gdp/jobshop.py
+++ b/examples/gdp/jobshop.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/gdp/medTermPurchasing_Literal.py b/examples/gdp/medTermPurchasing_Literal.py
index c9b27920396..b6d16c216fe 100755
--- a/examples/gdp/medTermPurchasing_Literal.py
+++ b/examples/gdp/medTermPurchasing_Literal.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 from pyomo.gdp import *
 
diff --git a/examples/gdp/nine_process/small_process.py b/examples/gdp/nine_process/small_process.py
index 2758069f316..2abffef1af6 100644
--- a/examples/gdp/nine_process/small_process.py
+++ b/examples/gdp/nine_process/small_process.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """Small process synthesis-inspired toy GDP example.
 
 """
diff --git a/examples/gdp/simple1.py b/examples/gdp/simple1.py
index f7c77b111f0..de41c0bfd00 100644
--- a/examples/gdp/simple1.py
+++ b/examples/gdp/simple1.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # Example: modeling a complementarity condition as a
 #   disjunction
 #
diff --git a/examples/gdp/simple2.py b/examples/gdp/simple2.py
index 6bcc7bbf747..b066d705036 100644
--- a/examples/gdp/simple2.py
+++ b/examples/gdp/simple2.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # Example: modeling a complementarity condition as a
 #   disjunction
 #
diff --git a/examples/gdp/simple3.py b/examples/gdp/simple3.py
index 6b3d6ec46c4..890daf8882b 100644
--- a/examples/gdp/simple3.py
+++ b/examples/gdp/simple3.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # Example: modeling a complementarity condition as a
 #   disjunction
 #
diff --git a/examples/gdp/small_lit/basic_step.py b/examples/gdp/small_lit/basic_step.py
index 48ef52d9ba0..2d9da97167c 100644
--- a/examples/gdp/small_lit/basic_step.py
+++ b/examples/gdp/small_lit/basic_step.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """ Example from Section 3.2 in paper of Pseudo Basic Steps
 
 Ref:
diff --git a/examples/gdp/small_lit/contracts_problem.py b/examples/gdp/small_lit/contracts_problem.py
index 500fe15cb2a..0c59d2264ee 100644
--- a/examples/gdp/small_lit/contracts_problem.py
+++ b/examples/gdp/small_lit/contracts_problem.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """ Example from 'Lagrangean Relaxation of the Hull-Reformulation of Linear \
     Generalized Disjunctive Programs and its use in Disjunctive Branch \
     and Bound' Page 25 f.
diff --git a/examples/gdp/small_lit/ex1_Lee.py b/examples/gdp/small_lit/ex1_Lee.py
index ddd2e1c3d2f..abbf470a1c3 100644
--- a/examples/gdp/small_lit/ex1_Lee.py
+++ b/examples/gdp/small_lit/ex1_Lee.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """Simple example of nonlinear problem modeled with GDP framework.
 Taken from Example 1 of the paper "New Algorithms for Nonlinear Generalized Disjunctive Programming" by Lee and Grossmann
 
diff --git a/examples/gdp/small_lit/ex_633_trespalacios.py b/examples/gdp/small_lit/ex_633_trespalacios.py
index 61b7294e3ba..b0c5fbd85ac 100644
--- a/examples/gdp/small_lit/ex_633_trespalacios.py
+++ b/examples/gdp/small_lit/ex_633_trespalacios.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """Analytical example from Section 6.3.3 of F. Trespalacions Ph.D. Thesis (2015)
 
 Analytical example for a nonconvex GDP with 2 disjunctions, each with 2 disjuncts.
diff --git a/examples/gdp/small_lit/nonconvex_HEN.py b/examples/gdp/small_lit/nonconvex_HEN.py
index 99e2c4f15e2..05fad970b84 100644
--- a/examples/gdp/small_lit/nonconvex_HEN.py
+++ b/examples/gdp/small_lit/nonconvex_HEN.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """ Example from 'Systematic Modeling of Discrete-Continuous Optimization \
       Models through Generalized Disjunctive Programming'
     Ignacio E. Grossmann and Francisco Trespalacios, 2013
diff --git a/examples/gdp/stickies.py b/examples/gdp/stickies.py
index 75beb911415..73b537ff13d 100644
--- a/examples/gdp/stickies.py
+++ b/examples/gdp/stickies.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import os
 
 from pyomo.common.fileutils import this_file_dir
diff --git a/examples/gdp/strip_packing/stripPacking.py b/examples/gdp/strip_packing/stripPacking.py
index 0e8902c5ee4..39f7208b838 100644
--- a/examples/gdp/strip_packing/stripPacking.py
+++ b/examples/gdp/strip_packing/stripPacking.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.core import *
 from pyomo.gdp import *
 
diff --git a/examples/gdp/strip_packing/strip_packing_8rect.py b/examples/gdp/strip_packing/strip_packing_8rect.py
index e1350dbc39e..2bd7c4840ca 100644
--- a/examples/gdp/strip_packing/strip_packing_8rect.py
+++ b/examples/gdp/strip_packing/strip_packing_8rect.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """Strip packing example from MINLP.org library.
 Strip-packing example from http://minlp.org/library/lib.php?lib=GDP
 This model packs a set of rectangles without rotation or overlap within a
diff --git a/examples/gdp/strip_packing/strip_packing_concrete.py b/examples/gdp/strip_packing/strip_packing_concrete.py
index 1313d75561c..b0907cdea61 100644
--- a/examples/gdp/strip_packing/strip_packing_concrete.py
+++ b/examples/gdp/strip_packing/strip_packing_concrete.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """Strip packing example from MINLP.org library.
 
 Strip-packing example from http://minlp.org/library/lib.php?lib=GDP
diff --git a/examples/gdp/two_rxn_lee/two_rxn_model.py b/examples/gdp/two_rxn_lee/two_rxn_model.py
index 2e5f1734130..98e4cc2e878 100644
--- a/examples/gdp/two_rxn_lee/two_rxn_model.py
+++ b/examples/gdp/two_rxn_lee/two_rxn_model.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """Two reactor model from literature. See README.md."""
 
 from pyomo.core import ConcreteModel, Constraint, Objective, Param, Var, maximize
diff --git a/examples/kernel/blocks.py b/examples/kernel/blocks.py
index 7036981dcc8..db1cb6655c2 100644
--- a/examples/kernel/blocks.py
+++ b/examples/kernel/blocks.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.kernel as pmo
 
 #
diff --git a/examples/kernel/conic.py b/examples/kernel/conic.py
index a2a787794a4..5ee66a00ee9 100644
--- a/examples/kernel/conic.py
+++ b/examples/kernel/conic.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.kernel as pmo
 
 #
diff --git a/examples/kernel/constraints.py b/examples/kernel/constraints.py
index 6495ad12f63..69823a6ebbe 100644
--- a/examples/kernel/constraints.py
+++ b/examples/kernel/constraints.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.kernel as pmo
 
 v = pmo.variable()
diff --git a/examples/kernel/containers.py b/examples/kernel/containers.py
index 9b525e87af6..9ec749b8c3e 100644
--- a/examples/kernel/containers.py
+++ b/examples/kernel/containers.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.kernel as pmo
 
 #
diff --git a/examples/kernel/expressions.py b/examples/kernel/expressions.py
index 1756e5d3fd4..faef8d1d4ad 100644
--- a/examples/kernel/expressions.py
+++ b/examples/kernel/expressions.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.kernel as pmo
 
 v = pmo.variable(value=2)
diff --git a/examples/kernel/mosek/geometric1.py b/examples/kernel/mosek/geometric1.py
index b5ec59541c4..8148e707819 100644
--- a/examples/kernel/mosek/geometric1.py
+++ b/examples/kernel/mosek/geometric1.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # Source: https://docs.mosek.com/9.0/pythonapi/tutorial-gp-shared.html
 
 import pyomo.kernel as pmo
diff --git a/examples/kernel/mosek/geometric2.py b/examples/kernel/mosek/geometric2.py
index 84825c0a39b..3fb62c86312 100644
--- a/examples/kernel/mosek/geometric2.py
+++ b/examples/kernel/mosek/geometric2.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # Source: https://docs.mosek.com/modeling-cookbook/expo.html
 #         (first example in Section 5.3.1)
 
diff --git a/examples/kernel/mosek/maximum_volume_cuboid.py b/examples/kernel/mosek/maximum_volume_cuboid.py
index 92e210cf400..df200cc801c 100644
--- a/examples/kernel/mosek/maximum_volume_cuboid.py
+++ b/examples/kernel/mosek/maximum_volume_cuboid.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from scipy.spatial import ConvexHull
 from mpl_toolkits.mplot3d import Axes3D
 from mpl_toolkits.mplot3d.art3d import Poly3DCollection
diff --git a/examples/kernel/mosek/power1.py b/examples/kernel/mosek/power1.py
index d7a12c1ce54..a6d6ebbe47d 100644
--- a/examples/kernel/mosek/power1.py
+++ b/examples/kernel/mosek/power1.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # Source: https://docs.mosek.com/9.0/pythonapi/tutorial-pow-shared.html
 
 import pyomo.kernel as pmo
diff --git a/examples/kernel/mosek/semidefinite.py b/examples/kernel/mosek/semidefinite.py
index 44ab7c95a68..6be47d85451 100644
--- a/examples/kernel/mosek/semidefinite.py
+++ b/examples/kernel/mosek/semidefinite.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # Source: https://docs.mosek.com/latest/pythonfusion/tutorial-sdo-shared.html#doc-tutorial-sdo
 
 # This examples illustrates SDP formulations in Pyomo using
diff --git a/examples/kernel/objectives.py b/examples/kernel/objectives.py
index 7d87671ef8d..27a41f4edb5 100644
--- a/examples/kernel/objectives.py
+++ b/examples/kernel/objectives.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.kernel as pmo
 
 v = pmo.variable(value=2)
diff --git a/examples/kernel/parameters.py b/examples/kernel/parameters.py
index 55b230add6b..e9e412525bb 100644
--- a/examples/kernel/parameters.py
+++ b/examples/kernel/parameters.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.kernel as pmo
 
 #
diff --git a/examples/kernel/piecewise_functions.py b/examples/kernel/piecewise_functions.py
index 528d4c16791..73a7f680725 100644
--- a/examples/kernel/piecewise_functions.py
+++ b/examples/kernel/piecewise_functions.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.kernel as pmo
 
 #
diff --git a/examples/kernel/piecewise_nd_functions.py b/examples/kernel/piecewise_nd_functions.py
index 847bb5f4a84..7de37fcbfc6 100644
--- a/examples/kernel/piecewise_nd_functions.py
+++ b/examples/kernel/piecewise_nd_functions.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import random
 import sys
 
diff --git a/examples/kernel/special_ordered_sets.py b/examples/kernel/special_ordered_sets.py
index 9526a551c12..abacc3d4205 100644
--- a/examples/kernel/special_ordered_sets.py
+++ b/examples/kernel/special_ordered_sets.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.kernel as pmo
 
 v1 = pmo.variable()
diff --git a/examples/kernel/suffixes.py b/examples/kernel/suffixes.py
index 39caa5b8652..ae95fbbdd09 100644
--- a/examples/kernel/suffixes.py
+++ b/examples/kernel/suffixes.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.kernel as pmo
 
 #
diff --git a/examples/kernel/variables.py b/examples/kernel/variables.py
index 7ab571245a1..36865b58183 100644
--- a/examples/kernel/variables.py
+++ b/examples/kernel/variables.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.kernel as pmo
 
 #
diff --git a/examples/mpec/bard1.py b/examples/mpec/bard1.py
index dbe666a7004..59955eefb8e 100644
--- a/examples/mpec/bard1.py
+++ b/examples/mpec/bard1.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # bard1.py QQR2-MN-8-5
 # Original Pyomo coding by William Hart
 # Adapted from AMPL coding by Sven Leyffer
diff --git a/examples/mpec/df.py b/examples/mpec/df.py
index 41984992bdd..7bb25b11e07 100644
--- a/examples/mpec/df.py
+++ b/examples/mpec/df.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/mpec/indexed.py b/examples/mpec/indexed.py
index b69d5093477..0aff5de5b20 100644
--- a/examples/mpec/indexed.py
+++ b/examples/mpec/indexed.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/mpec/linear1.py b/examples/mpec/linear1.py
index eba04759ae3..f24fd357e62 100644
--- a/examples/mpec/linear1.py
+++ b/examples/mpec/linear1.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/mpec/munson1.py b/examples/mpec/munson1.py
index debdf709db9..99c240b5c06 100644
--- a/examples/mpec/munson1.py
+++ b/examples/mpec/munson1.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/mpec/munson1a.py b/examples/mpec/munson1a.py
index 519db4e6ec2..67f8f318531 100644
--- a/examples/mpec/munson1a.py
+++ b/examples/mpec/munson1a.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/mpec/munson1b.py b/examples/mpec/munson1b.py
index ff2b7b51294..46fff90a785 100644
--- a/examples/mpec/munson1b.py
+++ b/examples/mpec/munson1b.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/mpec/munson1c.py b/examples/mpec/munson1c.py
index 2592b25c515..dee5b224e75 100644
--- a/examples/mpec/munson1c.py
+++ b/examples/mpec/munson1c.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/mpec/munson1d.py b/examples/mpec/munson1d.py
index 0fb08ce73fb..157177f2eb0 100644
--- a/examples/mpec/munson1d.py
+++ b/examples/mpec/munson1d.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/mpec/scholtes4.py b/examples/mpec/scholtes4.py
index 904729780cf..8d574dd1916 100644
--- a/examples/mpec/scholtes4.py
+++ b/examples/mpec/scholtes4.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # scholtes4.py	LQR2-MN-3-2
 # Original Pyomo coding by William Hart
 # Adapted from AMPL coding by Sven Leyffer
diff --git a/examples/performance/dae/run_stochpdegas1_automatic.py b/examples/performance/dae/run_stochpdegas1_automatic.py
index 993e22c7c86..fffa1a71ae1 100644
--- a/examples/performance/dae/run_stochpdegas1_automatic.py
+++ b/examples/performance/dae/run_stochpdegas1_automatic.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import time
 
 from pyomo.environ import *
diff --git a/examples/performance/dae/stochpdegas1_automatic.py b/examples/performance/dae/stochpdegas1_automatic.py
index 905ec9a5330..ce6132e6cf5 100644
--- a/examples/performance/dae/stochpdegas1_automatic.py
+++ b/examples/performance/dae/stochpdegas1_automatic.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # stochastic pde model for natural gas network
 # victor m. zavala / 2013
 
diff --git a/examples/performance/jump/clnlbeam.py b/examples/performance/jump/clnlbeam.py
index d2ceda790ec..410068a6753 100644
--- a/examples/performance/jump/clnlbeam.py
+++ b/examples/performance/jump/clnlbeam.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = AbstractModel()
diff --git a/examples/performance/jump/facility.py b/examples/performance/jump/facility.py
index 6832e8d32ac..fa0c306d6e5 100644
--- a/examples/performance/jump/facility.py
+++ b/examples/performance/jump/facility.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.core import *
 
 model = AbstractModel()
diff --git a/examples/performance/jump/lqcp.py b/examples/performance/jump/lqcp.py
index bb3e66b36f5..b8ef096d7be 100644
--- a/examples/performance/jump/lqcp.py
+++ b/examples/performance/jump/lqcp.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.core import *
 
 model = ConcreteModel()
diff --git a/examples/performance/jump/opf_66200bus.py b/examples/performance/jump/opf_66200bus.py
index f3e1822fbfb..702ff59a61c 100644
--- a/examples/performance/jump/opf_66200bus.py
+++ b/examples/performance/jump/opf_66200bus.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 
diff --git a/examples/performance/jump/opf_6620bus.py b/examples/performance/jump/opf_6620bus.py
index 64348ae931e..34b910f43c0 100644
--- a/examples/performance/jump/opf_6620bus.py
+++ b/examples/performance/jump/opf_6620bus.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 
diff --git a/examples/performance/jump/opf_662bus.py b/examples/performance/jump/opf_662bus.py
index 6ff97c577e3..8a768ca16e0 100644
--- a/examples/performance/jump/opf_662bus.py
+++ b/examples/performance/jump/opf_662bus.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 
diff --git a/examples/performance/misc/bilinear1_100.py b/examples/performance/misc/bilinear1_100.py
index e68fbba6283..d86091c4c76 100644
--- a/examples/performance/misc/bilinear1_100.py
+++ b/examples/performance/misc/bilinear1_100.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 
diff --git a/examples/performance/misc/bilinear1_100000.py b/examples/performance/misc/bilinear1_100000.py
index 924d7233d24..0fa2eafedc6 100644
--- a/examples/performance/misc/bilinear1_100000.py
+++ b/examples/performance/misc/bilinear1_100000.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 
diff --git a/examples/performance/misc/bilinear2_100.py b/examples/performance/misc/bilinear2_100.py
index 4dd9f9ead57..227bfe000e0 100644
--- a/examples/performance/misc/bilinear2_100.py
+++ b/examples/performance/misc/bilinear2_100.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 
diff --git a/examples/performance/misc/bilinear2_100000.py b/examples/performance/misc/bilinear2_100000.py
index 90eeaf82271..9d2a4d6fb7c 100644
--- a/examples/performance/misc/bilinear2_100000.py
+++ b/examples/performance/misc/bilinear2_100000.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 
diff --git a/examples/performance/misc/diag1_100.py b/examples/performance/misc/diag1_100.py
index e47a9179974..369d81982f0 100644
--- a/examples/performance/misc/diag1_100.py
+++ b/examples/performance/misc/diag1_100.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 
diff --git a/examples/performance/misc/diag1_100000.py b/examples/performance/misc/diag1_100000.py
index a110c0d9d67..536758fda5d 100644
--- a/examples/performance/misc/diag1_100000.py
+++ b/examples/performance/misc/diag1_100000.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 
diff --git a/examples/performance/misc/diag2_100.py b/examples/performance/misc/diag2_100.py
index fe820e8590b..6ad47528ff2 100644
--- a/examples/performance/misc/diag2_100.py
+++ b/examples/performance/misc/diag2_100.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 
diff --git a/examples/performance/misc/diag2_100000.py b/examples/performance/misc/diag2_100000.py
index 38563de57b9..b95e2dd1d6f 100644
--- a/examples/performance/misc/diag2_100000.py
+++ b/examples/performance/misc/diag2_100000.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 
diff --git a/examples/performance/misc/set1.py b/examples/performance/misc/set1.py
index 53227a3ee73..8a8b84fdcc3 100644
--- a/examples/performance/misc/set1.py
+++ b/examples/performance/misc/set1.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 model = ConcreteModel()
diff --git a/examples/performance/misc/sparse1.py b/examples/performance/misc/sparse1.py
index 264862760f9..b4883d379bc 100644
--- a/examples/performance/misc/sparse1.py
+++ b/examples/performance/misc/sparse1.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 #
 # This is a performance test that we cannot easily execute right now
 #
diff --git a/examples/performance/pmedian/pmedian1.py b/examples/performance/pmedian/pmedian1.py
index 3d3f6c5407f..a22540efdd5 100644
--- a/examples/performance/pmedian/pmedian1.py
+++ b/examples/performance/pmedian/pmedian1.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/performance/pmedian/pmedian2.py b/examples/performance/pmedian/pmedian2.py
index 434ded6dcbc..ff25a6c15eb 100644
--- a/examples/performance/pmedian/pmedian2.py
+++ b/examples/performance/pmedian/pmedian2.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/amplbook2/diet.py b/examples/pyomo/amplbook2/diet.py
index 8cdffefa20f..cc52eacae20 100644
--- a/examples/pyomo/amplbook2/diet.py
+++ b/examples/pyomo/amplbook2/diet.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/amplbook2/dieti.py b/examples/pyomo/amplbook2/dieti.py
index 0934dcf83c6..45d403dd810 100644
--- a/examples/pyomo/amplbook2/dieti.py
+++ b/examples/pyomo/amplbook2/dieti.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/amplbook2/econ2min.py b/examples/pyomo/amplbook2/econ2min.py
index 0d27df780bb..fb870e02364 100644
--- a/examples/pyomo/amplbook2/econ2min.py
+++ b/examples/pyomo/amplbook2/econ2min.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/amplbook2/econmin.py b/examples/pyomo/amplbook2/econmin.py
index 84e41107ff2..d9c95758d4d 100644
--- a/examples/pyomo/amplbook2/econmin.py
+++ b/examples/pyomo/amplbook2/econmin.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/amplbook2/prod.py b/examples/pyomo/amplbook2/prod.py
index 74e456e013f..236f7254b29 100644
--- a/examples/pyomo/amplbook2/prod.py
+++ b/examples/pyomo/amplbook2/prod.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/amplbook2/steel.py b/examples/pyomo/amplbook2/steel.py
index 43bea775526..8c5c9b2a1d3 100644
--- a/examples/pyomo/amplbook2/steel.py
+++ b/examples/pyomo/amplbook2/steel.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/amplbook2/steel3.py b/examples/pyomo/amplbook2/steel3.py
index e9e494b6a1a..dd3b3ac202f 100644
--- a/examples/pyomo/amplbook2/steel3.py
+++ b/examples/pyomo/amplbook2/steel3.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/amplbook2/steel4.py b/examples/pyomo/amplbook2/steel4.py
index b6709e478e9..10cb0979d24 100644
--- a/examples/pyomo/amplbook2/steel4.py
+++ b/examples/pyomo/amplbook2/steel4.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/benders/master.py b/examples/pyomo/benders/master.py
index a457bf28b06..372810dc024 100644
--- a/examples/pyomo/benders/master.py
+++ b/examples/pyomo/benders/master.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/benders/subproblem.py b/examples/pyomo/benders/subproblem.py
index 886f71ff321..ae46dad2d41 100644
--- a/examples/pyomo/benders/subproblem.py
+++ b/examples/pyomo/benders/subproblem.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/callbacks/sc.py b/examples/pyomo/callbacks/sc.py
index ce32b0a1074..0882815c6b7 100644
--- a/examples/pyomo/callbacks/sc.py
+++ b/examples/pyomo/callbacks/sc.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/callbacks/sc_callback.py b/examples/pyomo/callbacks/sc_callback.py
index 0dae9e1befc..cacc438b380 100644
--- a/examples/pyomo/callbacks/sc_callback.py
+++ b/examples/pyomo/callbacks/sc_callback.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/callbacks/sc_script.py b/examples/pyomo/callbacks/sc_script.py
index 8e4ade21b51..d3044e4d667 100644
--- a/examples/pyomo/callbacks/sc_script.py
+++ b/examples/pyomo/callbacks/sc_script.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/callbacks/scalability/run.py b/examples/pyomo/callbacks/scalability/run.py
index 8465e3f5019..cf95076fcc3 100644
--- a/examples/pyomo/callbacks/scalability/run.py
+++ b/examples/pyomo/callbacks/scalability/run.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/callbacks/tsp.py b/examples/pyomo/callbacks/tsp.py
index d3e28a98d3f..8526a540b66 100644
--- a/examples/pyomo/callbacks/tsp.py
+++ b/examples/pyomo/callbacks/tsp.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/columngeneration/cutting_stock.py b/examples/pyomo/columngeneration/cutting_stock.py
index 58df6a5ad16..2d9399c7db4 100644
--- a/examples/pyomo/columngeneration/cutting_stock.py
+++ b/examples/pyomo/columngeneration/cutting_stock.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/concrete/Whiskas.py b/examples/pyomo/concrete/Whiskas.py
index 9bc8dd87e9d..3d3c19e94ac 100644
--- a/examples/pyomo/concrete/Whiskas.py
+++ b/examples/pyomo/concrete/Whiskas.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/concrete/knapsack-abstract.py b/examples/pyomo/concrete/knapsack-abstract.py
index bbef95f7810..9766d902722 100644
--- a/examples/pyomo/concrete/knapsack-abstract.py
+++ b/examples/pyomo/concrete/knapsack-abstract.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/concrete/knapsack-concrete.py b/examples/pyomo/concrete/knapsack-concrete.py
index cd115ab40a3..8966d0b8498 100644
--- a/examples/pyomo/concrete/knapsack-concrete.py
+++ b/examples/pyomo/concrete/knapsack-concrete.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/concrete/rosen.py b/examples/pyomo/concrete/rosen.py
index a8e8a175127..ae51ae50ac0 100644
--- a/examples/pyomo/concrete/rosen.py
+++ b/examples/pyomo/concrete/rosen.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # rosen.py
 from pyomo.environ import *
 
diff --git a/examples/pyomo/concrete/sodacan.py b/examples/pyomo/concrete/sodacan.py
index 3c0cfd3aab2..5429b27a9d5 100644
--- a/examples/pyomo/concrete/sodacan.py
+++ b/examples/pyomo/concrete/sodacan.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # sodacan.py
 from pyomo.environ import *
 from math import pi
diff --git a/examples/pyomo/concrete/sodacan_fig.py b/examples/pyomo/concrete/sodacan_fig.py
index bf9ae476b4c..b263eaf558d 100644
--- a/examples/pyomo/concrete/sodacan_fig.py
+++ b/examples/pyomo/concrete/sodacan_fig.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from mpl_toolkits.mplot3d import Axes3D
 from matplotlib import cm
 from matplotlib.ticker import LinearLocator, FormatStrFormatter
diff --git a/examples/pyomo/concrete/sp.py b/examples/pyomo/concrete/sp.py
index edc2d68b170..e82a4bca0a9 100644
--- a/examples/pyomo/concrete/sp.py
+++ b/examples/pyomo/concrete/sp.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # sp.py
 from pyomo.environ import *
 from sp_data import *  # define c, b, h, and d
diff --git a/examples/pyomo/concrete/sp_data.py b/examples/pyomo/concrete/sp_data.py
index 58210126819..4453a10cead 100644
--- a/examples/pyomo/concrete/sp_data.py
+++ b/examples/pyomo/concrete/sp_data.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 c = 1.0
 b = 1.5
 h = 0.1
diff --git a/examples/pyomo/connectors/network_flow.py b/examples/pyomo/connectors/network_flow.py
index cb75ca7ecf2..d5587fdf4c8 100644
--- a/examples/pyomo/connectors/network_flow.py
+++ b/examples/pyomo/connectors/network_flow.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/connectors/network_flow_proposed.py b/examples/pyomo/connectors/network_flow_proposed.py
index ed603ff6626..f234f2decf4 100644
--- a/examples/pyomo/connectors/network_flow_proposed.py
+++ b/examples/pyomo/connectors/network_flow_proposed.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/core/block1.py b/examples/pyomo/core/block1.py
index 96f8114f19c..161fc2ca2f7 100644
--- a/examples/pyomo/core/block1.py
+++ b/examples/pyomo/core/block1.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/core/integrality1.py b/examples/pyomo/core/integrality1.py
index db81805555f..0ab3a433dac 100644
--- a/examples/pyomo/core/integrality1.py
+++ b/examples/pyomo/core/integrality1.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/core/integrality2.py b/examples/pyomo/core/integrality2.py
index 2d85c9f2455..6461d36f923 100644
--- a/examples/pyomo/core/integrality2.py
+++ b/examples/pyomo/core/integrality2.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/core/simple.py b/examples/pyomo/core/simple.py
index d0359c143bf..6976f3d25ad 100644
--- a/examples/pyomo/core/simple.py
+++ b/examples/pyomo/core/simple.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/core/t1.py b/examples/pyomo/core/t1.py
index 4135049d4be..5d5416985a9 100644
--- a/examples/pyomo/core/t1.py
+++ b/examples/pyomo/core/t1.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/core/t2.py b/examples/pyomo/core/t2.py
index 5d687917fba..4d3f1934cbe 100644
--- a/examples/pyomo/core/t2.py
+++ b/examples/pyomo/core/t2.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/core/t5.py b/examples/pyomo/core/t5.py
index 38605751015..6b9d94e0ff1 100644
--- a/examples/pyomo/core/t5.py
+++ b/examples/pyomo/core/t5.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/diet/diet-sqlite.py b/examples/pyomo/diet/diet-sqlite.py
index e8963485294..dccd3c338d0 100644
--- a/examples/pyomo/diet/diet-sqlite.py
+++ b/examples/pyomo/diet/diet-sqlite.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/diet/diet1.py b/examples/pyomo/diet/diet1.py
index 1fd61ca268c..217f80b9c25 100644
--- a/examples/pyomo/diet/diet1.py
+++ b/examples/pyomo/diet/diet1.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/diet/diet2.py b/examples/pyomo/diet/diet2.py
index 526dbcef484..291261b0901 100644
--- a/examples/pyomo/diet/diet2.py
+++ b/examples/pyomo/diet/diet2.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/draft/api.py b/examples/pyomo/draft/api.py
index 5b506882d9b..d785f41935e 100644
--- a/examples/pyomo/draft/api.py
+++ b/examples/pyomo/draft/api.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/draft/bpack.py b/examples/pyomo/draft/bpack.py
index 697ce531013..7b076f7737b 100644
--- a/examples/pyomo/draft/bpack.py
+++ b/examples/pyomo/draft/bpack.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/draft/diet2.py b/examples/pyomo/draft/diet2.py
index 9e4d2c5d9c4..d23fa3cf5db 100644
--- a/examples/pyomo/draft/diet2.py
+++ b/examples/pyomo/draft/diet2.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/p-median/decorated_pmedian.py b/examples/pyomo/p-median/decorated_pmedian.py
index 90345daf78d..c66971945f3 100644
--- a/examples/pyomo/p-median/decorated_pmedian.py
+++ b/examples/pyomo/p-median/decorated_pmedian.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 
 import random
diff --git a/examples/pyomo/p-median/pmedian.py b/examples/pyomo/p-median/pmedian.py
index 88731f287d8..865aa7cb61f 100644
--- a/examples/pyomo/p-median/pmedian.py
+++ b/examples/pyomo/p-median/pmedian.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/p-median/solver1.py b/examples/pyomo/p-median/solver1.py
index 113bf9fdd29..2652ab13943 100644
--- a/examples/pyomo/p-median/solver1.py
+++ b/examples/pyomo/p-median/solver1.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/p-median/solver2.py b/examples/pyomo/p-median/solver2.py
index c62f161fd24..50ec5388811 100644
--- a/examples/pyomo/p-median/solver2.py
+++ b/examples/pyomo/p-median/solver2.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/piecewise/convex.py b/examples/pyomo/piecewise/convex.py
index a3233ae5c3e..fb8095f80e3 100644
--- a/examples/pyomo/piecewise/convex.py
+++ b/examples/pyomo/piecewise/convex.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/piecewise/indexed.py b/examples/pyomo/piecewise/indexed.py
index dea56df3911..cde21ec847e 100644
--- a/examples/pyomo/piecewise/indexed.py
+++ b/examples/pyomo/piecewise/indexed.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/piecewise/indexed_nonlinear.py b/examples/pyomo/piecewise/indexed_nonlinear.py
index e871508d1be..d72fbc8a899 100644
--- a/examples/pyomo/piecewise/indexed_nonlinear.py
+++ b/examples/pyomo/piecewise/indexed_nonlinear.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/piecewise/indexed_points.py b/examples/pyomo/piecewise/indexed_points.py
index 15b1c33a7ec..66110bea342 100644
--- a/examples/pyomo/piecewise/indexed_points.py
+++ b/examples/pyomo/piecewise/indexed_points.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/piecewise/nonconvex.py b/examples/pyomo/piecewise/nonconvex.py
index 004748ab2eb..5300278d5b9 100644
--- a/examples/pyomo/piecewise/nonconvex.py
+++ b/examples/pyomo/piecewise/nonconvex.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/piecewise/points.py b/examples/pyomo/piecewise/points.py
index c822ceb5860..91d45684c4f 100644
--- a/examples/pyomo/piecewise/points.py
+++ b/examples/pyomo/piecewise/points.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/piecewise/step.py b/examples/pyomo/piecewise/step.py
index c3fbb4762ab..95aac74d7f7 100644
--- a/examples/pyomo/piecewise/step.py
+++ b/examples/pyomo/piecewise/step.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/quadratic/example1.py b/examples/pyomo/quadratic/example1.py
index dff911a0f0c..ab77c5a1733 100644
--- a/examples/pyomo/quadratic/example1.py
+++ b/examples/pyomo/quadratic/example1.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/quadratic/example2.py b/examples/pyomo/quadratic/example2.py
index 981f2ef0bfb..ce02c6f70c8 100644
--- a/examples/pyomo/quadratic/example2.py
+++ b/examples/pyomo/quadratic/example2.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/quadratic/example3.py b/examples/pyomo/quadratic/example3.py
index 4d96afe3328..bdba936f694 100644
--- a/examples/pyomo/quadratic/example3.py
+++ b/examples/pyomo/quadratic/example3.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/quadratic/example4.py b/examples/pyomo/quadratic/example4.py
index 256fc862a16..ecfc9981162 100644
--- a/examples/pyomo/quadratic/example4.py
+++ b/examples/pyomo/quadratic/example4.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/radertext/Ex2_1.py b/examples/pyomo/radertext/Ex2_1.py
index d352325798a..981388d4c72 100644
--- a/examples/pyomo/radertext/Ex2_1.py
+++ b/examples/pyomo/radertext/Ex2_1.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/radertext/Ex2_2.py b/examples/pyomo/radertext/Ex2_2.py
index 13c23dd1816..41b56e52669 100644
--- a/examples/pyomo/radertext/Ex2_2.py
+++ b/examples/pyomo/radertext/Ex2_2.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/radertext/Ex2_3.py b/examples/pyomo/radertext/Ex2_3.py
index d4dc3109ea1..7dc39afa773 100644
--- a/examples/pyomo/radertext/Ex2_3.py
+++ b/examples/pyomo/radertext/Ex2_3.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/radertext/Ex2_5.py b/examples/pyomo/radertext/Ex2_5.py
index da90b473b1f..fee49b46cb0 100644
--- a/examples/pyomo/radertext/Ex2_5.py
+++ b/examples/pyomo/radertext/Ex2_5.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/radertext/Ex2_6a.py b/examples/pyomo/radertext/Ex2_6a.py
index dc33a9b64e2..24bb866ec51 100644
--- a/examples/pyomo/radertext/Ex2_6a.py
+++ b/examples/pyomo/radertext/Ex2_6a.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/radertext/Ex2_6b.py b/examples/pyomo/radertext/Ex2_6b.py
index 8049d4ebb05..1be55461b9e 100644
--- a/examples/pyomo/radertext/Ex2_6b.py
+++ b/examples/pyomo/radertext/Ex2_6b.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/sos/DepotSiting.py b/examples/pyomo/sos/DepotSiting.py
index 98697681f44..40826e989b7 100644
--- a/examples/pyomo/sos/DepotSiting.py
+++ b/examples/pyomo/sos/DepotSiting.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/sos/basic_sos2_example.py b/examples/pyomo/sos/basic_sos2_example.py
index 655169ffe54..3aa0887356c 100644
--- a/examples/pyomo/sos/basic_sos2_example.py
+++ b/examples/pyomo/sos/basic_sos2_example.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/sos/sos2_piecewise.py b/examples/pyomo/sos/sos2_piecewise.py
index 4e79ce2ee62..79195761f3d 100644
--- a/examples/pyomo/sos/sos2_piecewise.py
+++ b/examples/pyomo/sos/sos2_piecewise.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/suffixes/duals_pyomo.py b/examples/pyomo/suffixes/duals_pyomo.py
index 9743add3ddd..6ce88fde429 100644
--- a/examples/pyomo/suffixes/duals_pyomo.py
+++ b/examples/pyomo/suffixes/duals_pyomo.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/suffixes/duals_script.py b/examples/pyomo/suffixes/duals_script.py
index a9db615cad3..e8ef9aef1bc 100644
--- a/examples/pyomo/suffixes/duals_script.py
+++ b/examples/pyomo/suffixes/duals_script.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/suffixes/gurobi_ampl_basis.py b/examples/pyomo/suffixes/gurobi_ampl_basis.py
index cd8e4e8f129..eab86f8aa47 100644
--- a/examples/pyomo/suffixes/gurobi_ampl_basis.py
+++ b/examples/pyomo/suffixes/gurobi_ampl_basis.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/suffixes/gurobi_ampl_example.py b/examples/pyomo/suffixes/gurobi_ampl_example.py
index d133fa422dc..4f3364c09dc 100644
--- a/examples/pyomo/suffixes/gurobi_ampl_example.py
+++ b/examples/pyomo/suffixes/gurobi_ampl_example.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/suffixes/gurobi_ampl_iis.py b/examples/pyomo/suffixes/gurobi_ampl_iis.py
index ccba226db78..da5bad073e7 100644
--- a/examples/pyomo/suffixes/gurobi_ampl_iis.py
+++ b/examples/pyomo/suffixes/gurobi_ampl_iis.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/suffixes/ipopt_scaling.py b/examples/pyomo/suffixes/ipopt_scaling.py
index c192a98dd98..7113128c21d 100644
--- a/examples/pyomo/suffixes/ipopt_scaling.py
+++ b/examples/pyomo/suffixes/ipopt_scaling.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/suffixes/ipopt_warmstart.py b/examples/pyomo/suffixes/ipopt_warmstart.py
index 6975bbaaa62..4882c48c8c8 100644
--- a/examples/pyomo/suffixes/ipopt_warmstart.py
+++ b/examples/pyomo/suffixes/ipopt_warmstart.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/suffixes/sipopt_hicks.py b/examples/pyomo/suffixes/sipopt_hicks.py
index dbf4e07b8f7..c7e058d5907 100644
--- a/examples/pyomo/suffixes/sipopt_hicks.py
+++ b/examples/pyomo/suffixes/sipopt_hicks.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/suffixes/sipopt_parametric.py b/examples/pyomo/suffixes/sipopt_parametric.py
index 29bba934bd8..0cb1c35f441 100644
--- a/examples/pyomo/suffixes/sipopt_parametric.py
+++ b/examples/pyomo/suffixes/sipopt_parametric.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/transform/scaling_ex.py b/examples/pyomo/transform/scaling_ex.py
index a5960393e75..34f937cbb45 100644
--- a/examples/pyomo/transform/scaling_ex.py
+++ b/examples/pyomo/transform/scaling_ex.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/tutorials/data.out b/examples/pyomo/tutorials/data.out
index d1353f87858..7dce6012e2f 100644
--- a/examples/pyomo/tutorials/data.out
+++ b/examples/pyomo/tutorials/data.out
@@ -1,4 +1,4 @@
-20 Set Declarations
+14 Set Declarations
     A : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    3 : {'A1', 'A2', 'A3'}
@@ -9,30 +9,18 @@
         Key  : Dimen : Domain : Size : Members
         None :     2 :    A*B :    9 : {('A1', 1), ('A1', 2), ('A1', 3), ('A2', 1), ('A2', 2), ('A2', 3), ('A3', 1), ('A3', 2), ('A3', 3)}
     D : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain   : Size : Members
-        None :     2 : D_domain :    3 : {('A1', 1), ('A2', 2), ('A3', 3)}
-    D_domain : Size=1, Index=None, Ordered=True
         Key  : Dimen : Domain : Size : Members
-        None :     2 :    A*B :    9 : {('A1', 1), ('A1', 2), ('A1', 3), ('A2', 1), ('A2', 2), ('A2', 3), ('A3', 1), ('A3', 2), ('A3', 3)}
+        None :     2 :    A*B :    3 : {('A1', 1), ('A2', 2), ('A3', 3)}
     E : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain   : Size : Members
-        None :     3 : E_domain :    6 : {('A1', 1, 'A1'), ('A1', 1, 'A2'), ('A2', 2, 'A2'), ('A2', 2, 'A3'), ('A3', 3, 'A1'), ('A3', 3, 'A3')}
-    E_domain : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain             : Size : Members
-        None :     3 : E_domain_index_0*A :   27 : {('A1', 1, 'A1'), ('A1', 1, 'A2'), ('A1', 1, 'A3'), ('A1', 2, 'A1'), ('A1', 2, 'A2'), ('A1', 2, 'A3'), ('A1', 3, 'A1'), ('A1', 3, 'A2'), ('A1', 3, 'A3'), ('A2', 1, 'A1'), ('A2', 1, 'A2'), ('A2', 1, 'A3'), ('A2', 2, 'A1'), ('A2', 2, 'A2'), ('A2', 2, 'A3'), ('A2', 3, 'A1'), ('A2', 3, 'A2'), ('A2', 3, 'A3'), ('A3', 1, 'A1'), ('A3', 1, 'A2'), ('A3', 1, 'A3'), ('A3', 2, 'A1'), ('A3', 2, 'A2'), ('A3', 2, 'A3'), ('A3', 3, 'A1'), ('A3', 3, 'A2'), ('A3', 3, 'A3')}
-    E_domain_index_0 : Size=1, Index=None, Ordered=True
         Key  : Dimen : Domain : Size : Members
-        None :     2 :    A*B :    9 : {('A1', 1), ('A1', 2), ('A1', 3), ('A2', 1), ('A2', 2), ('A2', 3), ('A3', 1), ('A3', 2), ('A3', 3)}
+        None :     3 :  A*B*A :    6 : {('A1', 1, 'A1'), ('A1', 1, 'A2'), ('A2', 2, 'A2'), ('A2', 2, 'A3'), ('A3', 3, 'A1'), ('A3', 3, 'A3')}
     F : Size=3, Index=A, Ordered=Insertion
         Key : Dimen : Domain : Size : Members
          A1 :     1 :    Any :    3 : {1, 3, 5}
          A2 :     1 :    Any :    3 : {2, 4, 6}
          A3 :     1 :    Any :    3 : {3, 5, 7}
-    G : Size=0, Index=G_index, Ordered=Insertion
+    G : Size=0, Index=A*B, Ordered=Insertion
         Key : Dimen : Domain : Size : Members
-    G_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    A*B :    9 : {('A1', 1), ('A1', 2), ('A1', 3), ('A2', 1), ('A2', 2), ('A2', 3), ('A3', 1), ('A3', 2), ('A3', 3)}
     H : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    3 : {'H1', 'H2', 'H3'}
@@ -45,12 +33,6 @@
     K : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     2 :    Any :    3 : {('A1', 'B1'), ('A2', 'B2'), ('A3', 'B3')}
-    T_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    A*I :   12 : {('A1', 'I1'), ('A1', 'I2'), ('A1', 'I3'), ('A1', 'I4'), ('A2', 'I1'), ('A2', 'I2'), ('A2', 'I3'), ('A2', 'I4'), ('A3', 'I1'), ('A3', 'I2'), ('A3', 'I3'), ('A3', 'I4')}
-    U_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    I*A :   12 : {('I1', 'A1'), ('I1', 'A2'), ('I1', 'A3'), ('I2', 'A1'), ('I2', 'A2'), ('I2', 'A3'), ('I3', 'A1'), ('I3', 'A2'), ('I3', 'A3'), ('I4', 'A1'), ('I4', 'A2'), ('I4', 'A3')}
     x : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    3 : {'A1', 'A2', 'A3'}
@@ -116,7 +98,7 @@
         Key : Value
          A1 :   3.3
          A3 :   3.5
-    T : Size=12, Index=T_index, Domain=Any, Default=None, Mutable=False
+    T : Size=12, Index=A*I, Domain=Any, Default=None, Mutable=False
         Key          : Value
         ('A1', 'I1') :   1.3
         ('A1', 'I2') :   1.4
@@ -130,7 +112,7 @@
         ('A3', 'I2') :   3.4
         ('A3', 'I3') :   3.5
         ('A3', 'I4') :   3.6
-    U : Size=12, Index=U_index, Domain=Any, Default=None, Mutable=False
+    U : Size=12, Index=I*A, Domain=Any, Default=None, Mutable=False
         Key          : Value
         ('I1', 'A1') :   1.3
         ('I1', 'A2') :   2.3
@@ -166,4 +148,4 @@
         Key  : Value
         None :     2
 
-38 Declarations: A B C D_domain D E_domain_index_0 E_domain E F G_index G H I J K Z ZZ Y X W U_index U T_index T S R Q P PP O z y x M N MM MMM NNN
+32 Declarations: A B C D E F G H I J K Z ZZ Y X W U T S R Q P PP O z y x M N MM MMM NNN
diff --git a/examples/pyomo/tutorials/data.py b/examples/pyomo/tutorials/data.py
index d065c9ff9bc..ea2569af934 100644
--- a/examples/pyomo/tutorials/data.py
+++ b/examples/pyomo/tutorials/data.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/tutorials/excel.out b/examples/pyomo/tutorials/excel.out
index 5064d4fa511..5e30827f7ae 100644
--- a/examples/pyomo/tutorials/excel.out
+++ b/examples/pyomo/tutorials/excel.out
@@ -1,4 +1,4 @@
-16 Set Declarations
+10 Set Declarations
     A : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    3 : {'A1', 'A2', 'A3'}
@@ -9,27 +9,15 @@
         Key  : Dimen : Domain : Size : Members
         None :     2 :    A*B :    9 : {('A1', 1.0), ('A1', 2.0), ('A1', 3.0), ('A2', 1.0), ('A2', 2.0), ('A2', 3.0), ('A3', 1.0), ('A3', 2.0), ('A3', 3.0)}
     D : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain   : Size : Members
-        None :     2 : D_domain :    3 : {('A1', 1.0), ('A2', 2.0), ('A3', 3.0)}
-    D_domain : Size=1, Index=None, Ordered=True
         Key  : Dimen : Domain : Size : Members
-        None :     2 :    A*B :    9 : {('A1', 1.0), ('A1', 2.0), ('A1', 3.0), ('A2', 1.0), ('A2', 2.0), ('A2', 3.0), ('A3', 1.0), ('A3', 2.0), ('A3', 3.0)}
+        None :     2 :    A*B :    3 : {('A1', 1.0), ('A2', 2.0), ('A3', 3.0)}
     E : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain   : Size : Members
-        None :     3 : E_domain :    6 : {('A1', 1.0, 'A1'), ('A1', 1.0, 'A2'), ('A2', 2.0, 'A2'), ('A2', 2.0, 'A3'), ('A3', 3.0, 'A1'), ('A3', 3.0, 'A3')}
-    E_domain : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain             : Size : Members
-        None :     3 : E_domain_index_0*A :   27 : {('A1', 1.0, 'A1'), ('A1', 1.0, 'A2'), ('A1', 1.0, 'A3'), ('A1', 2.0, 'A1'), ('A1', 2.0, 'A2'), ('A1', 2.0, 'A3'), ('A1', 3.0, 'A1'), ('A1', 3.0, 'A2'), ('A1', 3.0, 'A3'), ('A2', 1.0, 'A1'), ('A2', 1.0, 'A2'), ('A2', 1.0, 'A3'), ('A2', 2.0, 'A1'), ('A2', 2.0, 'A2'), ('A2', 2.0, 'A3'), ('A2', 3.0, 'A1'), ('A2', 3.0, 'A2'), ('A2', 3.0, 'A3'), ('A3', 1.0, 'A1'), ('A3', 1.0, 'A2'), ('A3', 1.0, 'A3'), ('A3', 2.0, 'A1'), ('A3', 2.0, 'A2'), ('A3', 2.0, 'A3'), ('A3', 3.0, 'A1'), ('A3', 3.0, 'A2'), ('A3', 3.0, 'A3')}
-    E_domain_index_0 : Size=1, Index=None, Ordered=True
         Key  : Dimen : Domain : Size : Members
-        None :     2 :    A*B :    9 : {('A1', 1.0), ('A1', 2.0), ('A1', 3.0), ('A2', 1.0), ('A2', 2.0), ('A2', 3.0), ('A3', 1.0), ('A3', 2.0), ('A3', 3.0)}
+        None :     3 :    A*B :    6 : {('A1', 1.0, 'A1'), ('A1', 1.0, 'A2'), ('A2', 2.0, 'A2'), ('A2', 2.0, 'A3'), ('A3', 3.0, 'A1'), ('A3', 3.0, 'A3')}
     F : Size=0, Index=A, Ordered=Insertion
         Key : Dimen : Domain : Size : Members
-    G : Size=0, Index=G_index, Ordered=Insertion
+    G : Size=0, Index=A*B, Ordered=Insertion
         Key : Dimen : Domain : Size : Members
-    G_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    A*B :    9 : {('A1', 1.0), ('A1', 2.0), ('A1', 3.0), ('A2', 1.0), ('A2', 2.0), ('A2', 3.0), ('A3', 1.0), ('A3', 2.0), ('A3', 3.0)}
     H : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    3 : {'H1', 'H2', 'H3'}
@@ -39,12 +27,6 @@
     J : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     2 :    Any :    3 : {('A1', 'B1'), ('A2', 'B2'), ('A3', 'B3')}
-    T_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    A*I :   12 : {('A1', 'I1'), ('A1', 'I2'), ('A1', 'I3'), ('A1', 'I4'), ('A2', 'I1'), ('A2', 'I2'), ('A2', 'I3'), ('A2', 'I4'), ('A3', 'I1'), ('A3', 'I2'), ('A3', 'I3'), ('A3', 'I4')}
-    U_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    I*A :   12 : {('I1', 'A1'), ('I1', 'A2'), ('I1', 'A3'), ('I2', 'A1'), ('I2', 'A2'), ('I2', 'A3'), ('I3', 'A1'), ('I3', 'A2'), ('I3', 'A3'), ('I4', 'A1'), ('I4', 'A2'), ('I4', 'A3')}
 
 12 Param Declarations
     O : Size=3, Index=J, Domain=Reals, Default=None, Mutable=False
@@ -76,7 +58,7 @@
         Key : Value
          A1 :   3.3
          A3 :   3.5
-    T : Size=12, Index=T_index, Domain=Any, Default=None, Mutable=False
+    T : Size=12, Index=A*I, Domain=Any, Default=None, Mutable=False
         Key          : Value
         ('A1', 'I1') :   1.3
         ('A1', 'I2') :   1.4
@@ -90,7 +72,7 @@
         ('A3', 'I2') :   3.4
         ('A3', 'I3') :   3.5
         ('A3', 'I4') :   3.6
-    U : Size=12, Index=U_index, Domain=Any, Default=None, Mutable=False
+    U : Size=12, Index=I*A, Domain=Any, Default=None, Mutable=False
         Key          : Value
         ('I1', 'A1') :   1.3
         ('I1', 'A2') :   2.3
@@ -123,4 +105,4 @@
         Key  : Value
         None :  1.01
 
-28 Declarations: A B C D_domain D E_domain_index_0 E_domain E F G_index G H I J Z Y X W U_index U T_index T S R Q P PP O
+22 Declarations: A B C D E F G H I J Z Y X W U T S R Q P PP O
diff --git a/examples/pyomo/tutorials/excel.py b/examples/pyomo/tutorials/excel.py
index 127db722c07..f9a5f66826b 100644
--- a/examples/pyomo/tutorials/excel.py
+++ b/examples/pyomo/tutorials/excel.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/tutorials/param.out b/examples/pyomo/tutorials/param.out
index 57e6a752ea5..ea258f5b493 100644
--- a/examples/pyomo/tutorials/param.out
+++ b/examples/pyomo/tutorials/param.out
@@ -1,22 +1,13 @@
-5 Set Declarations
+2 Set Declarations
     A : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    4 : {2, 4, 6, 8}
     B : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    3 : {1, 2, 3}
-    R_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    A*B :   12 : {(2, 1), (2, 2), (2, 3), (4, 1), (4, 2), (4, 3), (6, 1), (6, 2), (6, 3), (8, 1), (8, 2), (8, 3)}
-    W_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    A*B :   12 : {(2, 1), (2, 2), (2, 3), (4, 1), (4, 2), (4, 3), (6, 1), (6, 2), (6, 3), (8, 1), (8, 2), (8, 3)}
-    X_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    A*B :   12 : {(2, 1), (2, 2), (2, 3), (4, 1), (4, 2), (4, 3), (6, 1), (6, 2), (6, 3), (8, 1), (8, 2), (8, 3)}
 
 9 Param Declarations
-    R : Size=12, Index=R_index, Domain=Any, Default=99.0, Mutable=False
+    R : Size=12, Index=A*B, Domain=Any, Default=99.0, Mutable=False
         Key    : Value
         (2, 1) :     1
         (2, 2) :     1
@@ -35,7 +26,7 @@
           1 :     1
           2 :     2
           3 :     9
-    W : Size=12, Index=W_index, Domain=Any, Default=None, Mutable=False
+    W : Size=12, Index=A*B, Domain=Any, Default=None, Mutable=False
         Key    : Value
         (2, 1) :     2
         (2, 2) :     4
@@ -49,7 +40,7 @@
         (8, 1) :     8
         (8, 2) :    16
         (8, 3) :    24
-    X : Size=12, Index=X_index, Domain=Any, Default=None, Mutable=False
+    X : Size=12, Index=A*B, Domain=Any, Default=None, Mutable=False
         Key    : Value
         (2, 1) :   1.3
         (2, 2) :   1.4
@@ -73,4 +64,4 @@
         Key  : Value
         None :   1.1
 
-14 Declarations: A B Z Y X_index X W_index W V U T S R_index R
+11 Declarations: A B Z Y X W V U T S R
diff --git a/examples/pyomo/tutorials/param.py b/examples/pyomo/tutorials/param.py
index ba31975ab4b..5a94bafaa5e 100644
--- a/examples/pyomo/tutorials/param.py
+++ b/examples/pyomo/tutorials/param.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomo/tutorials/set.dat b/examples/pyomo/tutorials/set.dat
index ab0d00b43cc..e2ad04122d8 100644
--- a/examples/pyomo/tutorials/set.dat
+++ b/examples/pyomo/tutorials/set.dat
@@ -16,3 +16,6 @@ set S[5] := 2 3;
 
 set T[2] := 1 3;
 set T[5] := 2 3;
+
+set X[2] := 1;
+set X[5] := 2 3;
\ No newline at end of file
diff --git a/examples/pyomo/tutorials/set.out b/examples/pyomo/tutorials/set.out
index b01b666c012..dd1ef2d4335 100644
--- a/examples/pyomo/tutorials/set.out
+++ b/examples/pyomo/tutorials/set.out
@@ -1,15 +1,12 @@
-28 Set Declarations
+24 Set Declarations
     A : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    3 : {1, 2, 3}
     B : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    4 : {2, 3, 4, 5}
-    C : Size=0, Index=C_index, Ordered=Insertion
+    C : Size=0, Index=A*B, Ordered=Insertion
         Key : Dimen : Domain : Size : Members
-    C_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    A*B :   12 : {(1, 2), (1, 3), (1, 4), (1, 5), (2, 2), (2, 3), (2, 4), (2, 5), (3, 2), (3, 3), (3, 4), (3, 5)}
     D : Size=1, Index=None, Ordered=True
         Key  : Dimen : Domain : Size : Members
         None :     1 :  A | B :    5 : {1, 2, 3, 4, 5}
@@ -26,15 +23,9 @@
         Key  : Dimen : Domain : Size : Members
         None :     2 :    A*B :   12 : {(1, 2), (1, 3), (1, 4), (1, 5), (2, 2), (2, 3), (2, 4), (2, 5), (3, 2), (3, 3), (3, 4), (3, 5)}
     Hsub : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain      : Size : Members
-        None :     2 : Hsub_domain :    3 : {(1, 2), (1, 3), (3, 3)}
-    Hsub_domain : Size=1, Index=None, Ordered=True
         Key  : Dimen : Domain : Size : Members
-        None :     2 :    A*B :   12 : {(1, 2), (1, 3), (1, 4), (1, 5), (2, 2), (2, 3), (2, 4), (2, 5), (3, 2), (3, 3), (3, 4), (3, 5)}
+        None :     2 :    A*B :    3 : {(1, 2), (1, 3), (3, 3)}
     I : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain   : Size : Members
-        None :     2 : I_domain :   12 : {(1, 2), (1, 3), (1, 4), (1, 5), (2, 2), (2, 3), (2, 4), (2, 5), (3, 2), (3, 3), (3, 4), (3, 5)}
-    I_domain : Size=1, Index=None, Ordered=True
         Key  : Dimen : Domain : Size : Members
         None :     2 :    A*B :   12 : {(1, 2), (1, 3), (1, 4), (1, 5), (2, 2), (2, 3), (2, 4), (2, 5), (3, 2), (3, 3), (3, 4), (3, 5)}
     J : Size=1, Index=None, Ordered=Insertion
@@ -53,15 +44,12 @@
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    2 : {1, 3}
     N : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain   : Size : Members
-        None :     2 : N_domain :    0 :      {}
-    N_domain : Size=1, Index=None, Ordered=True
         Key  : Dimen : Domain : Size : Members
-        None :     2 :    A*B :   12 : {(1, 2), (1, 3), (1, 4), (1, 5), (2, 2), (2, 3), (2, 4), (2, 5), (3, 2), (3, 3), (3, 4), (3, 5)}
+        None :     2 :    A*B :    0 :      {}
     O : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :    -- :    Any :    0 :      {}
-    P : Size=16, Index=P_index, Ordered=Insertion
+    P : Size=16, Index=B*B, Ordered=Insertion
         Key    : Dimen : Domain : Size : Members
         (2, 2) :     1 :    Any :    4 : {0, 1, 2, 3}
         (2, 3) :     1 :    Any :    6 : {0, 1, 2, 3, 4, 5}
@@ -79,9 +67,6 @@
         (5, 3) :     1 :    Any :   15 : {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14}
         (5, 4) :     1 :    Any :   20 : {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19}
         (5, 5) :     1 :    Any :   25 : {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24}
-    P_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    B*B :   16 : {(2, 2), (2, 3), (2, 4), (2, 5), (3, 2), (3, 3), (3, 4), (3, 5), (4, 2), (4, 3), (4, 4), (4, 5), (5, 2), (5, 3), (5, 4), (5, 5)}
     R : Size=3, Index=B, Ordered=Insertion
         Key : Dimen : Domain : Size : Members
           2 :     1 :    Any :    3 : {1, 3, 5}
@@ -98,16 +83,15 @@
     U : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    5 : {1, 2, 6, 24, 120}
-    V : Size=4, Index=V_index, Ordered=Insertion
+    V : Size=4, Index=[1:4], Ordered=Insertion
         Key : Dimen : Domain : Size : Members
           1 :     1 :    Any :    5 : {1, 2, 3, 4, 5}
           2 :     1 :    Any :    5 : {1, 3, 5, 7, 9}
           3 :     1 :    Any :    5 : {1, 4, 7, 10, 13}
           4 :     1 :    Any :    5 : {1, 5, 9, 13, 17}
+    X : Size=2, Index=B, Ordered=Insertion
+        Key : Dimen : Domain : Size : Members
+          2 :     1 :   S[2] :    1 : {1,}
+          5 :     1 :   S[5] :    2 : {2, 3}
 
-1 RangeSet Declarations
-    V_index : Dimen=1, Size=4, Bounds=(1, 4)
-        Key  : Finite : Members
-        None :   True :   [1:4]
-
-29 Declarations: A B C_index C D E F G H Hsub_domain Hsub I_domain I J K K_2 L M N_domain N O P_index P R S T U V_index V
+24 Declarations: A B C D E F G H Hsub I J K K_2 L M N O P R S X T U V
diff --git a/examples/pyomo/tutorials/set.py b/examples/pyomo/tutorials/set.py
index 78f2656d739..c1ea60b48ad 100644
--- a/examples/pyomo/tutorials/set.py
+++ b/examples/pyomo/tutorials/set.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -171,6 +171,13 @@ def P_init(model, i, j):
 #
 model.S = Set(model.B, within=model.A)
 
+#
+# Validation of a set array can also be linked to another set array. If so, the
+# elements under each index must also be found under the corresponding index in
+# the validation set array:
+#
+model.X = Set(model.B, within=model.S)
+
 
 #
 # Validation of set arrays can also be performed with the _validate_ option.
diff --git a/examples/pyomo/tutorials/table.out b/examples/pyomo/tutorials/table.out
index 1eba28afd19..75e2b0aee33 100644
--- a/examples/pyomo/tutorials/table.out
+++ b/examples/pyomo/tutorials/table.out
@@ -1,4 +1,4 @@
-16 Set Declarations
+10 Set Declarations
     A : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    3 : {'A1', 'A2', 'A3'}
@@ -9,27 +9,15 @@
         Key  : Dimen : Domain : Size : Members
         None :     2 :    A*B :    9 : {('A1', 1), ('A1', 2), ('A1', 3), ('A2', 1), ('A2', 2), ('A2', 3), ('A3', 1), ('A3', 2), ('A3', 3)}
     D : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain   : Size : Members
-        None :     2 : D_domain :    3 : {('A1', 1), ('A2', 2), ('A3', 3)}
-    D_domain : Size=1, Index=None, Ordered=True
         Key  : Dimen : Domain : Size : Members
-        None :     2 :    A*B :    9 : {('A1', 1), ('A1', 2), ('A1', 3), ('A2', 1), ('A2', 2), ('A2', 3), ('A3', 1), ('A3', 2), ('A3', 3)}
+        None :     2 :    A*B :    3 : {('A1', 1), ('A2', 2), ('A3', 3)}
     E : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain   : Size : Members
-        None :     3 : E_domain :    6 : {('A1', 1, 'A1'), ('A1', 1, 'A2'), ('A2', 2, 'A2'), ('A2', 2, 'A3'), ('A3', 3, 'A1'), ('A3', 3, 'A3')}
-    E_domain : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain             : Size : Members
-        None :     3 : E_domain_index_0*A :   27 : {('A1', 1, 'A1'), ('A1', 1, 'A2'), ('A1', 1, 'A3'), ('A1', 2, 'A1'), ('A1', 2, 'A2'), ('A1', 2, 'A3'), ('A1', 3, 'A1'), ('A1', 3, 'A2'), ('A1', 3, 'A3'), ('A2', 1, 'A1'), ('A2', 1, 'A2'), ('A2', 1, 'A3'), ('A2', 2, 'A1'), ('A2', 2, 'A2'), ('A2', 2, 'A3'), ('A2', 3, 'A1'), ('A2', 3, 'A2'), ('A2', 3, 'A3'), ('A3', 1, 'A1'), ('A3', 1, 'A2'), ('A3', 1, 'A3'), ('A3', 2, 'A1'), ('A3', 2, 'A2'), ('A3', 2, 'A3'), ('A3', 3, 'A1'), ('A3', 3, 'A2'), ('A3', 3, 'A3')}
-    E_domain_index_0 : Size=1, Index=None, Ordered=True
         Key  : Dimen : Domain : Size : Members
-        None :     2 :    A*B :    9 : {('A1', 1), ('A1', 2), ('A1', 3), ('A2', 1), ('A2', 2), ('A2', 3), ('A3', 1), ('A3', 2), ('A3', 3)}
+        None :     3 :  A*B*A :    6 : {('A1', 1, 'A1'), ('A1', 1, 'A2'), ('A2', 2, 'A2'), ('A2', 2, 'A3'), ('A3', 3, 'A1'), ('A3', 3, 'A3')}
     F : Size=0, Index=A, Ordered=Insertion
         Key : Dimen : Domain : Size : Members
-    G : Size=0, Index=G_index, Ordered=Insertion
+    G : Size=0, Index=A*B, Ordered=Insertion
         Key : Dimen : Domain : Size : Members
-    G_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    A*B :    9 : {('A1', 1), ('A1', 2), ('A1', 3), ('A2', 1), ('A2', 2), ('A2', 3), ('A3', 1), ('A3', 2), ('A3', 3)}
     H : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    3 : {'H1', 'H2', 'H3'}
@@ -39,12 +27,6 @@
     J : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     2 :    Any :    3 : {('A1', 'B1'), ('A2', 'B2'), ('A3', 'B3')}
-    T_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    A*I :   12 : {('A1', 'I1'), ('A1', 'I2'), ('A1', 'I3'), ('A1', 'I4'), ('A2', 'I1'), ('A2', 'I2'), ('A2', 'I3'), ('A2', 'I4'), ('A3', 'I1'), ('A3', 'I2'), ('A3', 'I3'), ('A3', 'I4')}
-    U_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    I*A :   12 : {('I1', 'A1'), ('I1', 'A2'), ('I1', 'A3'), ('I2', 'A1'), ('I2', 'A2'), ('I2', 'A3'), ('I3', 'A1'), ('I3', 'A2'), ('I3', 'A3'), ('I4', 'A1'), ('I4', 'A2'), ('I4', 'A3')}
 
 12 Param Declarations
     O : Size=3, Index=J, Domain=Reals, Default=None, Mutable=False
@@ -76,7 +58,7 @@
         Key : Value
          A1 :   3.3
          A3 :   3.5
-    T : Size=12, Index=T_index, Domain=Any, Default=None, Mutable=False
+    T : Size=12, Index=A*I, Domain=Any, Default=None, Mutable=False
         Key          : Value
         ('A1', 'I1') :   1.3
         ('A1', 'I2') :   1.4
@@ -90,7 +72,7 @@
         ('A3', 'I2') :   3.4
         ('A3', 'I3') :   3.5
         ('A3', 'I4') :   3.6
-    U : Size=12, Index=U_index, Domain=Any, Default=None, Mutable=False
+    U : Size=12, Index=I*A, Domain=Any, Default=None, Mutable=False
         Key          : Value
         ('I1', 'A1') :   1.3
         ('I1', 'A2') :   2.3
@@ -123,4 +105,4 @@
         Key  : Value
         None :  1.01
 
-28 Declarations: A B C D_domain D E_domain_index_0 E_domain E F G_index G H I J Z Y X W U_index U T_index T S R Q P PP O
+22 Declarations: A B C D E F G H I J Z Y X W U T S R Q P PP O
diff --git a/examples/pyomo/tutorials/table.py b/examples/pyomo/tutorials/table.py
index 16951352ee1..7d9fceda14a 100644
--- a/examples/pyomo/tutorials/table.py
+++ b/examples/pyomo/tutorials/table.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomobook/__init__.py b/examples/pyomobook/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/examples/pyomobook/__init__.py
+++ b/examples/pyomobook/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/examples/pyomobook/abstract-ch/AbstHLinScript.py b/examples/pyomobook/abstract-ch/AbstHLinScript.py
index adf700bfd5c..687d3fc4e6b 100644
--- a/examples/pyomobook/abstract-ch/AbstHLinScript.py
+++ b/examples/pyomobook/abstract-ch/AbstHLinScript.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # AbstHLinScript.py - Script for a simple linear version of (H)
 
 import pyomo.environ as pyo
diff --git a/examples/pyomobook/abstract-ch/AbstractH.py b/examples/pyomobook/abstract-ch/AbstractH.py
index da9f0a4931c..7595cbc4933 100644
--- a/examples/pyomobook/abstract-ch/AbstractH.py
+++ b/examples/pyomobook/abstract-ch/AbstractH.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # AbstractH.py - Implement model (H)
 import pyomo.environ as pyo
 
diff --git a/examples/pyomobook/abstract-ch/AbstractHLinear.py b/examples/pyomobook/abstract-ch/AbstractHLinear.py
index 575487d3e95..f312020a9d5 100644
--- a/examples/pyomobook/abstract-ch/AbstractHLinear.py
+++ b/examples/pyomobook/abstract-ch/AbstractHLinear.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # AbstractHLinear.py - A simple linear version of (H)
 import pyomo.environ as pyo
 
diff --git a/examples/pyomobook/abstract-ch/abstract5.py b/examples/pyomobook/abstract-ch/abstract5.py
index 3a06256dff8..8849d2dfe7f 100644
--- a/examples/pyomobook/abstract-ch/abstract5.py
+++ b/examples/pyomobook/abstract-ch/abstract5.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # abstract5.py
 import pyomo.environ as pyo
 
diff --git a/examples/pyomobook/abstract-ch/abstract6.py b/examples/pyomobook/abstract-ch/abstract6.py
index d11a4652f64..121b12a51fa 100644
--- a/examples/pyomobook/abstract-ch/abstract6.py
+++ b/examples/pyomobook/abstract-ch/abstract6.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # abstract6.py
 import pyomo.environ as pyo
 
diff --git a/examples/pyomobook/abstract-ch/abstract7.py b/examples/pyomobook/abstract-ch/abstract7.py
index 2fd5d467d3e..3e8131bf42b 100644
--- a/examples/pyomobook/abstract-ch/abstract7.py
+++ b/examples/pyomobook/abstract-ch/abstract7.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # abstract7.py
 import pyomo.environ as pyo
 import pickle
diff --git a/examples/pyomobook/abstract-ch/buildactions.py b/examples/pyomobook/abstract-ch/buildactions.py
index ad918e2b5f2..6963f285c4c 100644
--- a/examples/pyomobook/abstract-ch/buildactions.py
+++ b/examples/pyomobook/abstract-ch/buildactions.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # buildactions.py: Warehouse location problem showing build actions
 import pyomo.environ as pyo
 
diff --git a/examples/pyomobook/abstract-ch/concrete1.py b/examples/pyomobook/abstract-ch/concrete1.py
index 0ad41c79ea3..2c89fbafaad 100644
--- a/examples/pyomobook/abstract-ch/concrete1.py
+++ b/examples/pyomobook/abstract-ch/concrete1.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.ConcreteModel()
diff --git a/examples/pyomobook/abstract-ch/concrete2.py b/examples/pyomobook/abstract-ch/concrete2.py
index 6aee434d556..f68c4d6e242 100644
--- a/examples/pyomobook/abstract-ch/concrete2.py
+++ b/examples/pyomobook/abstract-ch/concrete2.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.ConcreteModel()
diff --git a/examples/pyomobook/abstract-ch/diet1.py b/examples/pyomobook/abstract-ch/diet1.py
index eb8b071cdb5..fa8bf5f549f 100644
--- a/examples/pyomobook/abstract-ch/diet1.py
+++ b/examples/pyomobook/abstract-ch/diet1.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # diet1.py
 import pyomo.environ as pyo
 
diff --git a/examples/pyomobook/abstract-ch/ex.py b/examples/pyomobook/abstract-ch/ex.py
index 88005b7dc0c..83cfd445e01 100644
--- a/examples/pyomobook/abstract-ch/ex.py
+++ b/examples/pyomobook/abstract-ch/ex.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.AbstractModel()
diff --git a/examples/pyomobook/abstract-ch/param1.py b/examples/pyomobook/abstract-ch/param1.py
index fc9fac99ff4..3ff8b648661 100644
--- a/examples/pyomobook/abstract-ch/param1.py
+++ b/examples/pyomobook/abstract-ch/param1.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.AbstractModel()
diff --git a/examples/pyomobook/abstract-ch/param2.py b/examples/pyomobook/abstract-ch/param2.py
index d51cbeffe84..aca8fac0baf 100644
--- a/examples/pyomobook/abstract-ch/param2.py
+++ b/examples/pyomobook/abstract-ch/param2.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.AbstractModel()
diff --git a/examples/pyomobook/abstract-ch/param2a.py b/examples/pyomobook/abstract-ch/param2a.py
index fe928eb4197..6b6f77f2a8f 100644
--- a/examples/pyomobook/abstract-ch/param2a.py
+++ b/examples/pyomobook/abstract-ch/param2a.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.AbstractModel()
diff --git a/examples/pyomobook/abstract-ch/param3.py b/examples/pyomobook/abstract-ch/param3.py
index 64efba5c5ad..7545b47dadc 100644
--- a/examples/pyomobook/abstract-ch/param3.py
+++ b/examples/pyomobook/abstract-ch/param3.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.AbstractModel()
diff --git a/examples/pyomobook/abstract-ch/param3a.py b/examples/pyomobook/abstract-ch/param3a.py
index 857d96f8318..4c52b6432fb 100644
--- a/examples/pyomobook/abstract-ch/param3a.py
+++ b/examples/pyomobook/abstract-ch/param3a.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.AbstractModel()
diff --git a/examples/pyomobook/abstract-ch/param3b.py b/examples/pyomobook/abstract-ch/param3b.py
index 655694c33dd..786d6b58a16 100644
--- a/examples/pyomobook/abstract-ch/param3b.py
+++ b/examples/pyomobook/abstract-ch/param3b.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.AbstractModel()
diff --git a/examples/pyomobook/abstract-ch/param3c.py b/examples/pyomobook/abstract-ch/param3c.py
index 7d58b8b6a39..3f5da5f837e 100644
--- a/examples/pyomobook/abstract-ch/param3c.py
+++ b/examples/pyomobook/abstract-ch/param3c.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.AbstractModel()
diff --git a/examples/pyomobook/abstract-ch/param4.py b/examples/pyomobook/abstract-ch/param4.py
index c902b9034ad..c1926ddea74 100644
--- a/examples/pyomobook/abstract-ch/param4.py
+++ b/examples/pyomobook/abstract-ch/param4.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.AbstractModel()
diff --git a/examples/pyomobook/abstract-ch/param5.py b/examples/pyomobook/abstract-ch/param5.py
index 488e1debda8..7e0020f70b7 100644
--- a/examples/pyomobook/abstract-ch/param5.py
+++ b/examples/pyomobook/abstract-ch/param5.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.AbstractModel()
diff --git a/examples/pyomobook/abstract-ch/param5a.py b/examples/pyomobook/abstract-ch/param5a.py
index 7e814b917cc..efdd1855f3f 100644
--- a/examples/pyomobook/abstract-ch/param5a.py
+++ b/examples/pyomobook/abstract-ch/param5a.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.AbstractModel()
diff --git a/examples/pyomobook/abstract-ch/param6.py b/examples/pyomobook/abstract-ch/param6.py
index d9c49a548b2..f6d60f11e4b 100644
--- a/examples/pyomobook/abstract-ch/param6.py
+++ b/examples/pyomobook/abstract-ch/param6.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.AbstractModel()
diff --git a/examples/pyomobook/abstract-ch/param6a.py b/examples/pyomobook/abstract-ch/param6a.py
index e9aca384ee6..280e942d01d 100644
--- a/examples/pyomobook/abstract-ch/param6a.py
+++ b/examples/pyomobook/abstract-ch/param6a.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.AbstractModel()
diff --git a/examples/pyomobook/abstract-ch/param7a.py b/examples/pyomobook/abstract-ch/param7a.py
index 2a18cceabf6..21839bf3b64 100644
--- a/examples/pyomobook/abstract-ch/param7a.py
+++ b/examples/pyomobook/abstract-ch/param7a.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.AbstractModel()
diff --git a/examples/pyomobook/abstract-ch/param7b.py b/examples/pyomobook/abstract-ch/param7b.py
index acf02ddd62f..a4d79b6dee9 100644
--- a/examples/pyomobook/abstract-ch/param7b.py
+++ b/examples/pyomobook/abstract-ch/param7b.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.AbstractModel()
diff --git a/examples/pyomobook/abstract-ch/param8a.py b/examples/pyomobook/abstract-ch/param8a.py
index e68378961ed..f00ed649c30 100644
--- a/examples/pyomobook/abstract-ch/param8a.py
+++ b/examples/pyomobook/abstract-ch/param8a.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.AbstractModel()
diff --git a/examples/pyomobook/abstract-ch/postprocess_fn.py b/examples/pyomobook/abstract-ch/postprocess_fn.py
index f96a5b4dac1..2f2d114c216 100644
--- a/examples/pyomobook/abstract-ch/postprocess_fn.py
+++ b/examples/pyomobook/abstract-ch/postprocess_fn.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import csv
 
 
diff --git a/examples/pyomobook/abstract-ch/set1.py b/examples/pyomobook/abstract-ch/set1.py
index ee281bd10bd..5a23fe683e0 100644
--- a/examples/pyomobook/abstract-ch/set1.py
+++ b/examples/pyomobook/abstract-ch/set1.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.AbstractModel()
diff --git a/examples/pyomobook/abstract-ch/set2.py b/examples/pyomobook/abstract-ch/set2.py
index 27af609cead..5ecc0914bee 100644
--- a/examples/pyomobook/abstract-ch/set2.py
+++ b/examples/pyomobook/abstract-ch/set2.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.AbstractModel()
diff --git a/examples/pyomobook/abstract-ch/set2a.py b/examples/pyomobook/abstract-ch/set2a.py
index bf8f06dd7a8..7252ec0ad69 100644
--- a/examples/pyomobook/abstract-ch/set2a.py
+++ b/examples/pyomobook/abstract-ch/set2a.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.AbstractModel()
diff --git a/examples/pyomobook/abstract-ch/set3.py b/examples/pyomobook/abstract-ch/set3.py
index 7661963d19d..f3e3efc33c7 100644
--- a/examples/pyomobook/abstract-ch/set3.py
+++ b/examples/pyomobook/abstract-ch/set3.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.AbstractModel()
diff --git a/examples/pyomobook/abstract-ch/set4.py b/examples/pyomobook/abstract-ch/set4.py
index c9125dad657..0c29798b816 100644
--- a/examples/pyomobook/abstract-ch/set4.py
+++ b/examples/pyomobook/abstract-ch/set4.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.AbstractModel()
diff --git a/examples/pyomobook/abstract-ch/set5.py b/examples/pyomobook/abstract-ch/set5.py
index 9f79870d3ff..781b956404e 100644
--- a/examples/pyomobook/abstract-ch/set5.py
+++ b/examples/pyomobook/abstract-ch/set5.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.AbstractModel()
diff --git a/examples/pyomobook/abstract-ch/wl_abstract.py b/examples/pyomobook/abstract-ch/wl_abstract.py
index f35a5327bfb..61eeed6b506 100644
--- a/examples/pyomobook/abstract-ch/wl_abstract.py
+++ b/examples/pyomobook/abstract-ch/wl_abstract.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # wl_abstract.py: AbstractModel version of warehouse location determination problem
 import pyomo.environ as pyo
 
diff --git a/examples/pyomobook/abstract-ch/wl_abstract_script.py b/examples/pyomobook/abstract-ch/wl_abstract_script.py
index 0b042405714..7f0871350fc 100644
--- a/examples/pyomobook/abstract-ch/wl_abstract_script.py
+++ b/examples/pyomobook/abstract-ch/wl_abstract_script.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # wl_abstract_script.py: Scripting using an AbstractModel
 import pyomo.environ as pyo
 
diff --git a/examples/pyomobook/blocks-ch/blocks_gen.py b/examples/pyomobook/blocks-ch/blocks_gen.py
index 109e881cad5..31a4462f7d6 100644
--- a/examples/pyomobook/blocks-ch/blocks_gen.py
+++ b/examples/pyomobook/blocks-ch/blocks_gen.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 time = range(5)
diff --git a/examples/pyomobook/blocks-ch/blocks_gen.txt b/examples/pyomobook/blocks-ch/blocks_gen.txt
index 63d634b3b95..1636f7e4590 100644
--- a/examples/pyomobook/blocks-ch/blocks_gen.txt
+++ b/examples/pyomobook/blocks-ch/blocks_gen.txt
@@ -9,13 +9,8 @@
 1 Block Declarations
     Generator : Size=2, Index=GEN_UNITS, Active=True
         Generator[G_EAST] : Active=True
-            1 Set Declarations
-                CostCoef_index : Size=1, Index=None, Ordered=Insertion
-                    Key  : Dimen : Domain : Size : Members
-                    None :     1 :    Any :    2 : {1, 2}
-
             3 Param Declarations
-                CostCoef : Size=0, Index=Generator[G_EAST].CostCoef_index, Domain=Any, Default=None, Mutable=False
+                CostCoef : Size=0, Index={1, 2}, Domain=Any, Default=None, Mutable=False
                     Key : Value
                 MaxPower : Size=1, Index=None, Domain=NonNegativeReals, Default=None, Mutable=False
                     Key  : Value
@@ -27,11 +22,11 @@
             2 Var Declarations
                 Power : Size=5, Index=TIME
                     Key : Lower : Value : Upper : Fixed : Stale : Domain
-                      0 :     0 : 120.0 :   500 : False : False :  Reals
-                      1 :     0 : 145.0 :   500 : False : False :  Reals
-                      2 :     0 : 119.0 :   500 : False : False :  Reals
-                      3 :     0 :  42.0 :   500 : False : False :  Reals
-                      4 :     0 : 190.0 :   500 : False : False :  Reals
+                      0 :     0 : 120.0 : 500.0 : False : False :  Reals
+                      1 :     0 : 145.0 : 500.0 : False : False :  Reals
+                      2 :     0 : 119.0 : 500.0 : False : False :  Reals
+                      3 :     0 :  42.0 : 500.0 : False : False :  Reals
+                      4 :     0 : 190.0 : 500.0 : False : False :  Reals
                 UnitOn : Size=5, Index=TIME
                     Key : Lower : Value : Upper : Fixed : Stale : Domain
                       0 :     0 :  None :     1 : False :  True : Binary
@@ -57,15 +52,10 @@
                       3 : -50.0 : Generator[G_EAST].Power[3] - Generator[G_EAST].Power[2] : Generator[G_EAST].RampLimit :   True
                       4 : -50.0 : Generator[G_EAST].Power[4] - Generator[G_EAST].Power[3] : Generator[G_EAST].RampLimit :   True
 
-            8 Declarations: MaxPower RampLimit Power UnitOn limit_ramp CostCoef_index CostCoef Cost
+            7 Declarations: MaxPower RampLimit Power UnitOn limit_ramp CostCoef Cost
         Generator[G_MAIN] : Active=True
-            1 Set Declarations
-                CostCoef_index : Size=1, Index=None, Ordered=Insertion
-                    Key  : Dimen : Domain : Size : Members
-                    None :     1 :    Any :    2 : {1, 2}
-
             3 Param Declarations
-                CostCoef : Size=0, Index=Generator[G_MAIN].CostCoef_index, Domain=Any, Default=None, Mutable=False
+                CostCoef : Size=0, Index={1, 2}, Domain=Any, Default=None, Mutable=False
                     Key : Value
                 MaxPower : Size=1, Index=None, Domain=NonNegativeReals, Default=None, Mutable=False
                     Key  : Value
@@ -77,11 +67,11 @@
             2 Var Declarations
                 Power : Size=5, Index=TIME
                     Key : Lower : Value : Upper : Fixed : Stale : Domain
-                      0 :     0 : 120.0 :   500 : False : False :  Reals
-                      1 :     0 : 145.0 :   500 : False : False :  Reals
-                      2 :     0 : 119.0 :   500 : False : False :  Reals
-                      3 :     0 :  42.0 :   500 : False : False :  Reals
-                      4 :     0 : 190.0 :   500 : False : False :  Reals
+                      0 :     0 : 120.0 : 500.0 : False : False :  Reals
+                      1 :     0 : 145.0 : 500.0 : False : False :  Reals
+                      2 :     0 : 119.0 : 500.0 : False : False :  Reals
+                      3 :     0 :  42.0 : 500.0 : False : False :  Reals
+                      4 :     0 : 190.0 : 500.0 : False : False :  Reals
                 UnitOn : Size=5, Index=TIME
                     Key : Lower : Value : Upper : Fixed : Stale : Domain
                       0 :     0 :  None :     1 : False :  True : Binary
@@ -107,7 +97,7 @@
                       3 : -50.0 : Generator[G_MAIN].Power[3] - Generator[G_MAIN].Power[2] : Generator[G_MAIN].RampLimit :   True
                       4 : -50.0 : Generator[G_MAIN].Power[4] - Generator[G_MAIN].Power[3] : Generator[G_MAIN].RampLimit :   True
 
-            8 Declarations: MaxPower RampLimit Power UnitOn limit_ramp CostCoef_index CostCoef Cost
+            7 Declarations: MaxPower RampLimit Power UnitOn limit_ramp CostCoef Cost
 
 3 Declarations: TIME GEN_UNITS Generator
 2 Set Declarations
@@ -121,13 +111,8 @@
 1 Block Declarations
     Generator : Size=2, Index=GEN_UNITS, Active=True
         Generator[G_EAST] : Active=True
-            1 Set Declarations
-                CostCoef_index : Size=1, Index=None, Ordered=Insertion
-                    Key  : Dimen : Domain : Size : Members
-                    None :     1 :    Any :    2 : {1, 2}
-
             3 Param Declarations
-                CostCoef : Size=0, Index=Generator[G_EAST].CostCoef_index, Domain=Any, Default=None, Mutable=False
+                CostCoef : Size=0, Index={1, 2}, Domain=Any, Default=None, Mutable=False
                     Key : Value
                 MaxPower : Size=1, Index=None, Domain=NonNegativeReals, Default=None, Mutable=False
                     Key  : Value
@@ -139,11 +124,11 @@
             2 Var Declarations
                 Power : Size=5, Index=TIME
                     Key : Lower : Value : Upper : Fixed : Stale : Domain
-                      0 :     0 : 120.0 :   500 : False : False :  Reals
-                      1 :     0 : 145.0 :   500 : False : False :  Reals
-                      2 :     0 : 119.0 :   500 : False : False :  Reals
-                      3 :     0 :  42.0 :   500 : False : False :  Reals
-                      4 :     0 : 190.0 :   500 : False : False :  Reals
+                      0 :     0 : 120.0 : 500.0 : False : False :  Reals
+                      1 :     0 : 145.0 : 500.0 : False : False :  Reals
+                      2 :     0 : 119.0 : 500.0 : False : False :  Reals
+                      3 :     0 :  42.0 : 500.0 : False : False :  Reals
+                      4 :     0 : 190.0 : 500.0 : False : False :  Reals
                 UnitOn : Size=5, Index=TIME
                     Key : Lower : Value : Upper : Fixed : Stale : Domain
                       0 :     0 :  None :     1 : False :  True : Binary
@@ -169,15 +154,10 @@
                       3 : -50.0 : Generator[G_EAST].Power[3] - Generator[G_EAST].Power[2] : Generator[G_EAST].RampLimit :   True
                       4 : -50.0 : Generator[G_EAST].Power[4] - Generator[G_EAST].Power[3] : Generator[G_EAST].RampLimit :   True
 
-            8 Declarations: MaxPower RampLimit Power UnitOn limit_ramp CostCoef_index CostCoef Cost
+            7 Declarations: MaxPower RampLimit Power UnitOn limit_ramp CostCoef Cost
         Generator[G_MAIN] : Active=True
-            1 Set Declarations
-                CostCoef_index : Size=1, Index=None, Ordered=Insertion
-                    Key  : Dimen : Domain : Size : Members
-                    None :     1 :    Any :    2 : {1, 2}
-
             3 Param Declarations
-                CostCoef : Size=0, Index=Generator[G_MAIN].CostCoef_index, Domain=Any, Default=None, Mutable=False
+                CostCoef : Size=0, Index={1, 2}, Domain=Any, Default=None, Mutable=False
                     Key : Value
                 MaxPower : Size=1, Index=None, Domain=NonNegativeReals, Default=None, Mutable=False
                     Key  : Value
@@ -189,11 +169,11 @@
             2 Var Declarations
                 Power : Size=5, Index=TIME
                     Key : Lower : Value : Upper : Fixed : Stale : Domain
-                      0 :     0 : 120.0 :   500 : False : False :  Reals
-                      1 :     0 : 145.0 :   500 : False : False :  Reals
-                      2 :     0 : 119.0 :   500 : False : False :  Reals
-                      3 :     0 :  42.0 :   500 : False : False :  Reals
-                      4 :     0 : 190.0 :   500 : False : False :  Reals
+                      0 :     0 : 120.0 : 500.0 : False : False :  Reals
+                      1 :     0 : 145.0 : 500.0 : False : False :  Reals
+                      2 :     0 : 119.0 : 500.0 : False : False :  Reals
+                      3 :     0 :  42.0 : 500.0 : False : False :  Reals
+                      4 :     0 : 190.0 : 500.0 : False : False :  Reals
                 UnitOn : Size=5, Index=TIME
                     Key : Lower : Value : Upper : Fixed : Stale : Domain
                       0 :     0 :  None :     1 : False :  True : Binary
@@ -219,7 +199,7 @@
                       3 : -50.0 : Generator[G_MAIN].Power[3] - Generator[G_MAIN].Power[2] : Generator[G_MAIN].RampLimit :   True
                       4 : -50.0 : Generator[G_MAIN].Power[4] - Generator[G_MAIN].Power[3] : Generator[G_MAIN].RampLimit :   True
 
-            8 Declarations: MaxPower RampLimit Power UnitOn limit_ramp CostCoef_index CostCoef Cost
+            7 Declarations: MaxPower RampLimit Power UnitOn limit_ramp CostCoef Cost
 
 3 Declarations: TIME GEN_UNITS Generator
 Generator[G_MAIN].Power[4] = 190.0
diff --git a/examples/pyomobook/blocks-ch/blocks_intro.py b/examples/pyomobook/blocks-ch/blocks_intro.py
index ad3ceaa4349..ba2bd9d3a97 100644
--- a/examples/pyomobook/blocks-ch/blocks_intro.py
+++ b/examples/pyomobook/blocks-ch/blocks_intro.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 # @hierarchy:
diff --git a/examples/pyomobook/blocks-ch/blocks_lotsizing.py b/examples/pyomobook/blocks-ch/blocks_lotsizing.py
index fe0717d8c7c..758ad964dc5 100644
--- a/examples/pyomobook/blocks-ch/blocks_lotsizing.py
+++ b/examples/pyomobook/blocks-ch/blocks_lotsizing.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.ConcreteModel()
diff --git a/examples/pyomobook/blocks-ch/lotsizing.py b/examples/pyomobook/blocks-ch/lotsizing.py
index 47ea265246e..ece4d6b541c 100644
--- a/examples/pyomobook/blocks-ch/lotsizing.py
+++ b/examples/pyomobook/blocks-ch/lotsizing.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.ConcreteModel()
diff --git a/examples/pyomobook/blocks-ch/lotsizing_no_time.py b/examples/pyomobook/blocks-ch/lotsizing_no_time.py
index 901467a0cbb..60e8ba44424 100644
--- a/examples/pyomobook/blocks-ch/lotsizing_no_time.py
+++ b/examples/pyomobook/blocks-ch/lotsizing_no_time.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.ConcreteModel()
diff --git a/examples/pyomobook/blocks-ch/lotsizing_uncertain.py b/examples/pyomobook/blocks-ch/lotsizing_uncertain.py
index 6d16de7e3a7..f72161db5c6 100644
--- a/examples/pyomobook/blocks-ch/lotsizing_uncertain.py
+++ b/examples/pyomobook/blocks-ch/lotsizing_uncertain.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.ConcreteModel()
diff --git a/examples/pyomobook/blocks-ch/lotsizing_uncertain.txt b/examples/pyomobook/blocks-ch/lotsizing_uncertain.txt
index db9eee79cc3..08f92ae9262 100644
--- a/examples/pyomobook/blocks-ch/lotsizing_uncertain.txt
+++ b/examples/pyomobook/blocks-ch/lotsizing_uncertain.txt
@@ -1,20 +1,3 @@
-5 Set Declarations
-    i_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    T*S :   25 : {(1, 1), (1, 2), (1, 3), (1, 4), (1, 5), (2, 1), (2, 2), (2, 3), (2, 4), (2, 5), (3, 1), (3, 2), (3, 3), (3, 4), (3, 5), (4, 1), (4, 2), (4, 3), (4, 4), (4, 5), (5, 1), (5, 2), (5, 3), (5, 4), (5, 5)}
-    i_neg_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    T*S :   25 : {(1, 1), (1, 2), (1, 3), (1, 4), (1, 5), (2, 1), (2, 2), (2, 3), (2, 4), (2, 5), (3, 1), (3, 2), (3, 3), (3, 4), (3, 5), (4, 1), (4, 2), (4, 3), (4, 4), (4, 5), (5, 1), (5, 2), (5, 3), (5, 4), (5, 5)}
-    i_pos_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    T*S :   25 : {(1, 1), (1, 2), (1, 3), (1, 4), (1, 5), (2, 1), (2, 2), (2, 3), (2, 4), (2, 5), (3, 1), (3, 2), (3, 3), (3, 4), (3, 5), (4, 1), (4, 2), (4, 3), (4, 4), (4, 5), (5, 1), (5, 2), (5, 3), (5, 4), (5, 5)}
-    x_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    T*S :   25 : {(1, 1), (1, 2), (1, 3), (1, 4), (1, 5), (2, 1), (2, 2), (2, 3), (2, 4), (2, 5), (3, 1), (3, 2), (3, 3), (3, 4), (3, 5), (4, 1), (4, 2), (4, 3), (4, 4), (4, 5), (5, 1), (5, 2), (5, 3), (5, 4), (5, 5)}
-    y_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    T*S :   25 : {(1, 1), (1, 2), (1, 3), (1, 4), (1, 5), (2, 1), (2, 2), (2, 3), (2, 4), (2, 5), (3, 1), (3, 2), (3, 3), (3, 4), (3, 5), (4, 1), (4, 2), (4, 3), (4, 4), (4, 5), (5, 1), (5, 2), (5, 3), (5, 4), (5, 5)}
-
 2 RangeSet Declarations
     S : Dimen=1, Size=5, Bounds=(1, 5)
         Key  : Finite : Members
@@ -24,7 +7,7 @@
         None :   True :   [1:5]
 
 5 Var Declarations
-    i : Size=25, Index=i_index
+    i : Size=25, Index=T*S
         Key    : Lower : Value : Upper : Fixed : Stale : Domain
         (1, 1) :  None :  None :  None : False :  True :  Reals
         (1, 2) :  None :  None :  None : False :  True :  Reals
@@ -51,7 +34,7 @@
         (5, 3) :  None :  None :  None : False :  True :  Reals
         (5, 4) :  None :  None :  None : False :  True :  Reals
         (5, 5) :  None :  None :  None : False :  True :  Reals
-    i_neg : Size=25, Index=i_neg_index
+    i_neg : Size=25, Index=T*S
         Key    : Lower : Value : Upper : Fixed : Stale : Domain
         (1, 1) :     0 :  None :  None : False :  True : NonNegativeReals
         (1, 2) :     0 :  None :  None : False :  True : NonNegativeReals
@@ -78,7 +61,7 @@
         (5, 3) :     0 :  None :  None : False :  True : NonNegativeReals
         (5, 4) :     0 :  None :  None : False :  True : NonNegativeReals
         (5, 5) :     0 :  None :  None : False :  True : NonNegativeReals
-    i_pos : Size=25, Index=i_pos_index
+    i_pos : Size=25, Index=T*S
         Key    : Lower : Value : Upper : Fixed : Stale : Domain
         (1, 1) :     0 :  None :  None : False :  True : NonNegativeReals
         (1, 2) :     0 :  None :  None : False :  True : NonNegativeReals
@@ -105,7 +88,7 @@
         (5, 3) :     0 :  None :  None : False :  True : NonNegativeReals
         (5, 4) :     0 :  None :  None : False :  True : NonNegativeReals
         (5, 5) :     0 :  None :  None : False :  True : NonNegativeReals
-    x : Size=25, Index=x_index
+    x : Size=25, Index=T*S
         Key    : Lower : Value : Upper : Fixed : Stale : Domain
         (1, 1) :     0 :  None :  None : False :  True : NonNegativeReals
         (1, 2) :     0 :  None :  None : False :  True : NonNegativeReals
@@ -132,7 +115,7 @@
         (5, 3) :     0 :  None :  None : False :  True : NonNegativeReals
         (5, 4) :     0 :  None :  None : False :  True : NonNegativeReals
         (5, 5) :     0 :  None :  None : False :  True : NonNegativeReals
-    y : Size=25, Index=y_index
+    y : Size=25, Index=T*S
         Key    : Lower : Value : Upper : Fixed : Stale : Domain
         (1, 1) :     0 :  None :     1 : False :  True : Binary
         (1, 2) :     0 :  None :     1 : False :  True : Binary
@@ -160,4 +143,4 @@
         (5, 4) :     0 :  None :     1 : False :  True : Binary
         (5, 5) :     0 :  None :     1 : False :  True : Binary
 
-12 Declarations: T S y_index y x_index x i_index i i_pos_index i_pos i_neg_index i_neg
+7 Declarations: T S y x i i_pos i_neg
diff --git a/examples/pyomobook/dae-ch/dae_tester_model.py b/examples/pyomobook/dae-ch/dae_tester_model.py
index 9e0da9f4a62..396b8a53db1 100644
--- a/examples/pyomobook/dae-ch/dae_tester_model.py
+++ b/examples/pyomobook/dae-ch/dae_tester_model.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # This is a file for testing miscellaneous code snippets from the DAE chapter
 import pyomo.environ as pyo
 import pyomo.dae as dae
diff --git a/examples/pyomobook/dae-ch/path_constraint.py b/examples/pyomobook/dae-ch/path_constraint.py
index 5fe41dd132d..5e252d1b99f 100644
--- a/examples/pyomobook/dae-ch/path_constraint.py
+++ b/examples/pyomobook/dae-ch/path_constraint.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/examples/pyomobook/dae-ch/path_constraint.txt b/examples/pyomobook/dae-ch/path_constraint.txt
index 421692b33e9..97e56ab8816 100644
--- a/examples/pyomobook/dae-ch/path_constraint.txt
+++ b/examples/pyomobook/dae-ch/path_constraint.txt
@@ -1,8 +1,3 @@
-1 RangeSet Declarations
-    t_domain : Dimen=1, Size=Inf, Bounds=(0, 1)
-        Key  : Finite : Members
-        None :  False :  [0..1]
-
 1 Param Declarations
     tf : Size=1, Index=None, Domain=Any, Default=None, Mutable=False
         Key  : Value
@@ -68,4 +63,4 @@
           0 :  None :  None :  None : False :  True :  Reals
           1 :  None :  None :  None : False :  True :  Reals
 
-15 Declarations: tf t_domain t u x1 x2 x3 dx1 dx2 dx3 x1dotcon x2dotcon x3dotcon obj con
+14 Declarations: tf t u x1 x2 x3 dx1 dx2 dx3 x1dotcon x2dotcon x3dotcon obj con
diff --git a/examples/pyomobook/dae-ch/plot_path_constraint.py b/examples/pyomobook/dae-ch/plot_path_constraint.py
index 4c04bc1b6b6..be86f13cbc0 100644
--- a/examples/pyomobook/dae-ch/plot_path_constraint.py
+++ b/examples/pyomobook/dae-ch/plot_path_constraint.py
@@ -1,3 +1,15 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+
 # @plot_path:
 def plotter(subplot, x, *y, **kwds):
     plt.subplot(subplot)
diff --git a/examples/pyomobook/dae-ch/run_path_constraint.py b/examples/pyomobook/dae-ch/run_path_constraint.py
index b819d6a7127..fc115f5649c 100644
--- a/examples/pyomobook/dae-ch/run_path_constraint.py
+++ b/examples/pyomobook/dae-ch/run_path_constraint.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 from pyomo.dae import *
 from path_constraint import m
diff --git a/examples/pyomobook/dae-ch/run_path_constraint_tester.py b/examples/pyomobook/dae-ch/run_path_constraint_tester.py
index bbcd83f5da5..22d887e9b11 100644
--- a/examples/pyomobook/dae-ch/run_path_constraint_tester.py
+++ b/examples/pyomobook/dae-ch/run_path_constraint_tester.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.common.tee import capture_output
 from six import StringIO
 
diff --git a/examples/pyomobook/gdp-ch/gdp_uc.py b/examples/pyomobook/gdp-ch/gdp_uc.py
index 2495ed9bef1..6268bcce068 100644
--- a/examples/pyomobook/gdp-ch/gdp_uc.py
+++ b/examples/pyomobook/gdp-ch/gdp_uc.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # gdp_uc.py
 import pyomo.environ as pyo
 from pyomo.gdp import *
diff --git a/examples/pyomobook/gdp-ch/scont.py b/examples/pyomobook/gdp-ch/scont.py
index 76597326700..d1cf4b172bd 100644
--- a/examples/pyomobook/gdp-ch/scont.py
+++ b/examples/pyomobook/gdp-ch/scont.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # scont.py
 import pyomo.environ as pyo
 from pyomo.gdp import Disjunct, Disjunction
diff --git a/examples/pyomobook/gdp-ch/scont2.py b/examples/pyomobook/gdp-ch/scont2.py
index 94e510b358a..2c77fe670d5 100644
--- a/examples/pyomobook/gdp-ch/scont2.py
+++ b/examples/pyomobook/gdp-ch/scont2.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 import scont
diff --git a/examples/pyomobook/gdp-ch/scont_script.py b/examples/pyomobook/gdp-ch/scont_script.py
index 22c9b88ad0c..fe0702dc262 100644
--- a/examples/pyomobook/gdp-ch/scont_script.py
+++ b/examples/pyomobook/gdp-ch/scont_script.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 import scont
 
diff --git a/examples/pyomobook/gdp-ch/verify_scont.py b/examples/pyomobook/gdp-ch/verify_scont.py
index db44024fe66..222453560b6 100644
--- a/examples/pyomobook/gdp-ch/verify_scont.py
+++ b/examples/pyomobook/gdp-ch/verify_scont.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import os
 
 
diff --git a/examples/pyomobook/intro-ch/abstract5.py b/examples/pyomobook/intro-ch/abstract5.py
index 2184ed7b3aa..2caad5f9351 100644
--- a/examples/pyomobook/intro-ch/abstract5.py
+++ b/examples/pyomobook/intro-ch/abstract5.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.AbstractModel()
diff --git a/examples/pyomobook/intro-ch/coloring_concrete.py b/examples/pyomobook/intro-ch/coloring_concrete.py
index 107a31668c4..9931b5d80de 100644
--- a/examples/pyomobook/intro-ch/coloring_concrete.py
+++ b/examples/pyomobook/intro-ch/coloring_concrete.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 #
 # Graph coloring example adapted from
 #
diff --git a/examples/pyomobook/intro-ch/concrete1.py b/examples/pyomobook/intro-ch/concrete1.py
index a39ca1d41cd..169fbeb281c 100644
--- a/examples/pyomobook/intro-ch/concrete1.py
+++ b/examples/pyomobook/intro-ch/concrete1.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.ConcreteModel()
diff --git a/examples/pyomobook/intro-ch/concrete1_generic.py b/examples/pyomobook/intro-ch/concrete1_generic.py
index de648470469..9a2d26bded8 100644
--- a/examples/pyomobook/intro-ch/concrete1_generic.py
+++ b/examples/pyomobook/intro-ch/concrete1_generic.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 import mydata
 
diff --git a/examples/pyomobook/intro-ch/mydata.py b/examples/pyomobook/intro-ch/mydata.py
index 83aa26bacd9..209546ebeaf 100644
--- a/examples/pyomobook/intro-ch/mydata.py
+++ b/examples/pyomobook/intro-ch/mydata.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 N = [1, 2]
 M = [1, 2]
 c = {1: 1, 2: 2}
diff --git a/examples/pyomobook/mpec-ch/ex1a.py b/examples/pyomobook/mpec-ch/ex1a.py
index 30cd2842556..e6f1c33fbbc 100644
--- a/examples/pyomobook/mpec-ch/ex1a.py
+++ b/examples/pyomobook/mpec-ch/ex1a.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # ex1a.py
 import pyomo.environ as pyo
 from pyomo.mpec import Complementarity, complements
diff --git a/examples/pyomobook/mpec-ch/ex1b.py b/examples/pyomobook/mpec-ch/ex1b.py
index 9592c81c4f6..2b0ac2ce1b7 100644
--- a/examples/pyomobook/mpec-ch/ex1b.py
+++ b/examples/pyomobook/mpec-ch/ex1b.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # ex1b.py
 import pyomo.environ as pyo
 from pyomo.mpec import ComplementarityList, complements
diff --git a/examples/pyomobook/mpec-ch/ex1c.py b/examples/pyomobook/mpec-ch/ex1c.py
index aad9c9b0d47..eaf0292b50d 100644
--- a/examples/pyomobook/mpec-ch/ex1c.py
+++ b/examples/pyomobook/mpec-ch/ex1c.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # ex1c.py
 import pyomo.environ as pyo
 from pyomo.mpec import ComplementarityList, complements
diff --git a/examples/pyomobook/mpec-ch/ex1d.py b/examples/pyomobook/mpec-ch/ex1d.py
index fa5247ff831..4c0e0d9fd0f 100644
--- a/examples/pyomobook/mpec-ch/ex1d.py
+++ b/examples/pyomobook/mpec-ch/ex1d.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # ex1d.py
 import pyomo.environ as pyo
 from pyomo.mpec import Complementarity, complements
diff --git a/examples/pyomobook/mpec-ch/ex1e.py b/examples/pyomobook/mpec-ch/ex1e.py
index bf714411396..c552847fcfb 100644
--- a/examples/pyomobook/mpec-ch/ex1e.py
+++ b/examples/pyomobook/mpec-ch/ex1e.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # ex1e.py
 import pyomo.environ as pyo
 from pyomo.mpec import ComplementarityList, complements
diff --git a/examples/pyomobook/mpec-ch/ex2.py b/examples/pyomobook/mpec-ch/ex2.py
index c192ccc7a34..6981af33376 100644
--- a/examples/pyomobook/mpec-ch/ex2.py
+++ b/examples/pyomobook/mpec-ch/ex2.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # ex2.py
 import pyomo.environ as pyo
 from pyomo.mpec import *
diff --git a/examples/pyomobook/mpec-ch/munson1.py b/examples/pyomobook/mpec-ch/munson1.py
index c7d171eb416..e85d9359768 100644
--- a/examples/pyomobook/mpec-ch/munson1.py
+++ b/examples/pyomobook/mpec-ch/munson1.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # munson1.py
 import pyomo.environ as pyo
 from pyomo.mpec import Complementarity, complements
diff --git a/examples/pyomobook/mpec-ch/ralph1.py b/examples/pyomobook/mpec-ch/ralph1.py
index 1d44a303b84..b6a8b45e8df 100644
--- a/examples/pyomobook/mpec-ch/ralph1.py
+++ b/examples/pyomobook/mpec-ch/ralph1.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # ralph1.py
 import pyomo.environ as pyo
 from pyomo.mpec import Complementarity, complements
diff --git a/examples/pyomobook/nonlinear-ch/deer/DeerProblem.py b/examples/pyomobook/nonlinear-ch/deer/DeerProblem.py
index c076a7f4687..dc3ca179a58 100644
--- a/examples/pyomobook/nonlinear-ch/deer/DeerProblem.py
+++ b/examples/pyomobook/nonlinear-ch/deer/DeerProblem.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # DeerProblem.py
 import pyomo.environ as pyo
 
diff --git a/examples/pyomobook/nonlinear-ch/disease_est/disease_estimation.py b/examples/pyomobook/nonlinear-ch/disease_est/disease_estimation.py
index 4eb859dc349..5675d7a715b 100644
--- a/examples/pyomobook/nonlinear-ch/disease_est/disease_estimation.py
+++ b/examples/pyomobook/nonlinear-ch/disease_est/disease_estimation.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # disease_estimation.py
 import pyomo.environ as pyo
 
diff --git a/examples/pyomobook/nonlinear-ch/multimodal/multimodal_init1.py b/examples/pyomobook/nonlinear-ch/multimodal/multimodal_init1.py
index c435cafc3d5..a50bf3321d6 100644
--- a/examples/pyomobook/nonlinear-ch/multimodal/multimodal_init1.py
+++ b/examples/pyomobook/nonlinear-ch/multimodal/multimodal_init1.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # multimodal_init1.py
 import pyomo.environ as pyo
 from math import pi
diff --git a/examples/pyomobook/nonlinear-ch/multimodal/multimodal_init2.py b/examples/pyomobook/nonlinear-ch/multimodal/multimodal_init2.py
index aa0dbae1e66..6a209334521 100644
--- a/examples/pyomobook/nonlinear-ch/multimodal/multimodal_init2.py
+++ b/examples/pyomobook/nonlinear-ch/multimodal/multimodal_init2.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 from math import pi
 
diff --git a/examples/pyomobook/nonlinear-ch/react_design/ReactorDesign.py b/examples/pyomobook/nonlinear-ch/react_design/ReactorDesign.py
index 90822c153a5..1cfe3b7193f 100644
--- a/examples/pyomobook/nonlinear-ch/react_design/ReactorDesign.py
+++ b/examples/pyomobook/nonlinear-ch/react_design/ReactorDesign.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ
 import pyomo.environ as pyo
 
diff --git a/examples/pyomobook/nonlinear-ch/react_design/ReactorDesignTable.py b/examples/pyomobook/nonlinear-ch/react_design/ReactorDesignTable.py
index a242c85fbc2..2bd9574b427 100644
--- a/examples/pyomobook/nonlinear-ch/react_design/ReactorDesignTable.py
+++ b/examples/pyomobook/nonlinear-ch/react_design/ReactorDesignTable.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 from ReactorDesign import create_model
 
diff --git a/examples/pyomobook/nonlinear-ch/rosen/rosenbrock.py b/examples/pyomobook/nonlinear-ch/rosen/rosenbrock.py
index e1633e2df69..bec1d04c12c 100644
--- a/examples/pyomobook/nonlinear-ch/rosen/rosenbrock.py
+++ b/examples/pyomobook/nonlinear-ch/rosen/rosenbrock.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # rosenbrock.py
 # A Pyomo model for the Rosenbrock problem
 import pyomo.environ as pyo
diff --git a/examples/pyomobook/optimization-ch/ConcHLinScript.py b/examples/pyomobook/optimization-ch/ConcHLinScript.py
index 8481a83afbf..b94903585dc 100644
--- a/examples/pyomobook/optimization-ch/ConcHLinScript.py
+++ b/examples/pyomobook/optimization-ch/ConcHLinScript.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # ConcHLinScript.py - Linear (H) as a script
 import pyomo.environ as pyo
 
diff --git a/examples/pyomobook/optimization-ch/ConcHLinScript.txt b/examples/pyomobook/optimization-ch/ConcHLinScript.txt
index c04591c94dc..0d34868ed99 100644
--- a/examples/pyomobook/optimization-ch/ConcHLinScript.txt
+++ b/examples/pyomobook/optimization-ch/ConcHLinScript.txt
@@ -1,7 +1,7 @@
 Model 'Linear (H)'
 
   Variables:
-    x : Size=2, Index=x_index
+    x : Size=2, Index={I_C_Scoops, Peanuts}
         Key        : Lower : Value : Upper : Fixed : Stale : Domain
         I_C_Scoops :     0 :   0.0 :   100 : False : False :  Reals
            Peanuts :     0 :  40.6 :  40.6 : False : False :  Reals
@@ -9,7 +9,7 @@ Model 'Linear (H)'
   Objectives:
     z : Size=1, Index=None, Active=True
         Key  : Active : Value
-        None :   True : 3.83388751715
+        None :   True : 3.8338875171467763
 
   Constraints:
     budgetconstr : Size=1
diff --git a/examples/pyomobook/optimization-ch/ConcreteH.py b/examples/pyomobook/optimization-ch/ConcreteH.py
index 1bf2a9446c1..d7474291d0d 100644
--- a/examples/pyomobook/optimization-ch/ConcreteH.py
+++ b/examples/pyomobook/optimization-ch/ConcreteH.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # ConcreteH.py - Implement a particular instance of (H)
 
 # @fct:
diff --git a/examples/pyomobook/optimization-ch/ConcreteH.txt b/examples/pyomobook/optimization-ch/ConcreteH.txt
index 5e669ff71e0..04bbbdab857 100644
--- a/examples/pyomobook/optimization-ch/ConcreteH.txt
+++ b/examples/pyomobook/optimization-ch/ConcreteH.txt
@@ -1,10 +1,5 @@
-1 Set Declarations
-    x_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    2 : {'I_C_Scoops', 'Peanuts'}
-
 1 Var Declarations
-    x : Size=2, Index=x_index
+    x : Size=2, Index={I_C_Scoops, Peanuts}
         Key        : Lower : Value : Upper : Fixed : Stale : Domain
         I_C_Scoops :     0 :  None :   100 : False :  True :  Reals
            Peanuts :     0 :  None :  40.6 : False :  True :  Reals
@@ -19,4 +14,4 @@
         Key  : Lower : Body                                   : Upper : Active
         None :  -Inf : 3.14*x[I_C_Scoops] + 0.2718*x[Peanuts] :  12.0 :   True
 
-4 Declarations: x_index x z budgetconstr
+3 Declarations: x z budgetconstr
diff --git a/examples/pyomobook/optimization-ch/ConcreteHLinear.py b/examples/pyomobook/optimization-ch/ConcreteHLinear.py
index 0b42d5e2187..772c18cb6d5 100644
--- a/examples/pyomobook/optimization-ch/ConcreteHLinear.py
+++ b/examples/pyomobook/optimization-ch/ConcreteHLinear.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # ConcreteHLinear.py - Linear (H)
 import pyomo.environ as pyo
 
diff --git a/examples/pyomobook/optimization-ch/ConcreteHLinear.txt b/examples/pyomobook/optimization-ch/ConcreteHLinear.txt
index 2e778c2bd1b..7f19aca87ec 100644
--- a/examples/pyomobook/optimization-ch/ConcreteHLinear.txt
+++ b/examples/pyomobook/optimization-ch/ConcreteHLinear.txt
@@ -1,10 +1,5 @@
-1 Set Declarations
-    x_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    2 : {'I_C_Scoops', 'Peanuts'}
-
 1 Var Declarations
-    x : Size=2, Index=x_index
+    x : Size=2, Index={I_C_Scoops, Peanuts}
         Key        : Lower : Value : Upper : Fixed : Stale : Domain
         I_C_Scoops :     0 :  None :   100 : False :  True :  Reals
            Peanuts :     0 :  None :  40.6 : False :  True :  Reals
@@ -19,4 +14,4 @@
         Key  : Lower : Body                                   : Upper : Active
         None :  -Inf : 3.14*x[I_C_Scoops] + 0.2718*x[Peanuts] :  12.0 :   True
 
-4 Declarations: x_index x z budgetconstr
+3 Declarations: x z budgetconstr
diff --git a/examples/pyomobook/optimization-ch/IC_model_dict.py b/examples/pyomobook/optimization-ch/IC_model_dict.py
index 4c54ef83701..b7e359777c7 100644
--- a/examples/pyomobook/optimization-ch/IC_model_dict.py
+++ b/examples/pyomobook/optimization-ch/IC_model_dict.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # IC_model_dict.py - Implement a particular instance of (H)
 
 # @fct:
diff --git a/examples/pyomobook/overview-ch/var_obj_con_snippet.py b/examples/pyomobook/overview-ch/var_obj_con_snippet.py
index 49bb7c1276b..22524b5815a 100644
--- a/examples/pyomobook/overview-ch/var_obj_con_snippet.py
+++ b/examples/pyomobook/overview-ch/var_obj_con_snippet.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.ConcreteModel()
diff --git a/examples/pyomobook/overview-ch/wl_abstract.py b/examples/pyomobook/overview-ch/wl_abstract.py
index f35a5327bfb..61eeed6b506 100644
--- a/examples/pyomobook/overview-ch/wl_abstract.py
+++ b/examples/pyomobook/overview-ch/wl_abstract.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # wl_abstract.py: AbstractModel version of warehouse location determination problem
 import pyomo.environ as pyo
 
diff --git a/examples/pyomobook/overview-ch/wl_abstract_script.py b/examples/pyomobook/overview-ch/wl_abstract_script.py
index 0b042405714..7f0871350fc 100644
--- a/examples/pyomobook/overview-ch/wl_abstract_script.py
+++ b/examples/pyomobook/overview-ch/wl_abstract_script.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # wl_abstract_script.py: Scripting using an AbstractModel
 import pyomo.environ as pyo
 
diff --git a/examples/pyomobook/overview-ch/wl_concrete.py b/examples/pyomobook/overview-ch/wl_concrete.py
index 29316304f0a..c1bf70b07f1 100644
--- a/examples/pyomobook/overview-ch/wl_concrete.py
+++ b/examples/pyomobook/overview-ch/wl_concrete.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # wl_concrete.py
 # ConcreteModel version of warehouse location problem
 import pyomo.environ as pyo
diff --git a/examples/pyomobook/overview-ch/wl_concrete_script.py b/examples/pyomobook/overview-ch/wl_concrete_script.py
index 278937f5aed..b369521994c 100644
--- a/examples/pyomobook/overview-ch/wl_concrete_script.py
+++ b/examples/pyomobook/overview-ch/wl_concrete_script.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # wl_concrete_script.py
 # Solve an instance of the warehouse location problem
 
diff --git a/examples/pyomobook/overview-ch/wl_concrete_script.txt b/examples/pyomobook/overview-ch/wl_concrete_script.txt
index dae31e1a035..165289552d3 100644
--- a/examples/pyomobook/overview-ch/wl_concrete_script.txt
+++ b/examples/pyomobook/overview-ch/wl_concrete_script.txt
@@ -1,4 +1,4 @@
-y : Size=3, Index=y_index
+y : Size=3, Index={Harlingen, Memphis, Ashland}
     Key       : Lower : Value : Upper : Fixed : Stale : Domain
       Ashland :     0 :   1.0 :     1 : False : False : Binary
     Harlingen :     0 :   1.0 :     1 : False : False : Binary
diff --git a/examples/pyomobook/overview-ch/wl_excel.py b/examples/pyomobook/overview-ch/wl_excel.py
index 1c4ad997225..180e36422fe 100644
--- a/examples/pyomobook/overview-ch/wl_excel.py
+++ b/examples/pyomobook/overview-ch/wl_excel.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # wl_excel.py: Loading Excel data using Pandas
 import pandas
 import pyomo.environ as pyo
diff --git a/examples/pyomobook/overview-ch/wl_excel.txt b/examples/pyomobook/overview-ch/wl_excel.txt
index dae31e1a035..165289552d3 100644
--- a/examples/pyomobook/overview-ch/wl_excel.txt
+++ b/examples/pyomobook/overview-ch/wl_excel.txt
@@ -1,4 +1,4 @@
-y : Size=3, Index=y_index
+y : Size=3, Index={Harlingen, Memphis, Ashland}
     Key       : Lower : Value : Upper : Fixed : Stale : Domain
       Ashland :     0 :   1.0 :     1 : False : False : Binary
     Harlingen :     0 :   1.0 :     1 : False : False : Binary
diff --git a/examples/pyomobook/overview-ch/wl_list.py b/examples/pyomobook/overview-ch/wl_list.py
index 64db76be548..37cba5a9595 100644
--- a/examples/pyomobook/overview-ch/wl_list.py
+++ b/examples/pyomobook/overview-ch/wl_list.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # wl_list.py: Warehouse location problem using constraint lists
 import pyomo.environ as pyo
 
diff --git a/examples/pyomobook/overview-ch/wl_list.txt b/examples/pyomobook/overview-ch/wl_list.txt
index 2054efe153d..c0d44f1a0c9 100644
--- a/examples/pyomobook/overview-ch/wl_list.txt
+++ b/examples/pyomobook/overview-ch/wl_list.txt
@@ -1,25 +1,5 @@
-6 Set Declarations
-    demand_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    4 : {1, 2, 3, 4}
-    warehouse_active_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :   12 : {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12}
-    x_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain              : Size : Members
-        None :     2 : x_index_0*x_index_1 :   12 : {('Harlingen', 'NYC'), ('Harlingen', 'LA'), ('Harlingen', 'Chicago'), ('Harlingen', 'Houston'), ('Memphis', 'NYC'), ('Memphis', 'LA'), ('Memphis', 'Chicago'), ('Memphis', 'Houston'), ('Ashland', 'NYC'), ('Ashland', 'LA'), ('Ashland', 'Chicago'), ('Ashland', 'Houston')}
-    x_index_0 : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    3 : {'Harlingen', 'Memphis', 'Ashland'}
-    x_index_1 : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    4 : {'NYC', 'LA', 'Chicago', 'Houston'}
-    y_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    3 : {'Harlingen', 'Memphis', 'Ashland'}
-
 2 Var Declarations
-    x : Size=12, Index=x_index
+    x : Size=12, Index={Harlingen, Memphis, Ashland}*{NYC, LA, Chicago, Houston}
         Key                      : Lower : Value : Upper : Fixed : Stale : Domain
           ('Ashland', 'Chicago') :     0 :  None :     1 : False :  True :  Reals
           ('Ashland', 'Houston') :     0 :  None :     1 : False :  True :  Reals
@@ -33,7 +13,7 @@
           ('Memphis', 'Houston') :     0 :  None :     1 : False :  True :  Reals
                ('Memphis', 'LA') :     0 :  None :     1 : False :  True :  Reals
               ('Memphis', 'NYC') :     0 :  None :     1 : False :  True :  Reals
-    y : Size=3, Index=y_index
+    y : Size=3, Index={Harlingen, Memphis, Ashland}
         Key       : Lower : Value : Upper : Fixed : Stale : Domain
           Ashland :     0 :  None :     1 : False :  True : Binary
         Harlingen :     0 :  None :     1 : False :  True : Binary
@@ -45,7 +25,7 @@
         None :   True : minimize : 1956*x[Harlingen,NYC] + 1606*x[Harlingen,LA] + 1410*x[Harlingen,Chicago] + 330*x[Harlingen,Houston] + 1096*x[Memphis,NYC] + 1792*x[Memphis,LA] + 531*x[Memphis,Chicago] + 567*x[Memphis,Houston] + 485*x[Ashland,NYC] + 2322*x[Ashland,LA] + 324*x[Ashland,Chicago] + 1236*x[Ashland,Houston]
 
 3 Constraint Declarations
-    demand : Size=4, Index=demand_index, Active=True
+    demand : Size=4, Index={1, 2, 3, 4}, Active=True
         Key : Lower : Body                                                           : Upper : Active
           1 :   1.0 :             x[Harlingen,NYC] + x[Memphis,NYC] + x[Ashland,NYC] :   1.0 :   True
           2 :   1.0 :                x[Harlingen,LA] + x[Memphis,LA] + x[Ashland,LA] :   1.0 :   True
@@ -54,7 +34,7 @@
     num_warehouses : Size=1, Index=None, Active=True
         Key  : Lower : Body                                   : Upper : Active
         None :  -Inf : y[Harlingen] + y[Memphis] + y[Ashland] :   2.0 :   True
-    warehouse_active : Size=12, Index=warehouse_active_index, Active=True
+    warehouse_active : Size=12, Index={1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12}, Active=True
         Key : Lower : Body                                : Upper : Active
           1 :  -Inf :     x[Harlingen,NYC] - y[Harlingen] :   0.0 :   True
           2 :  -Inf :      x[Harlingen,LA] - y[Harlingen] :   0.0 :   True
@@ -69,4 +49,4 @@
          11 :  -Inf :     x[Ashland,Chicago] - y[Ashland] :   0.0 :   True
          12 :  -Inf :     x[Ashland,Houston] - y[Ashland] :   0.0 :   True
 
-12 Declarations: x_index_0 x_index_1 x_index x y_index y obj demand_index demand warehouse_active_index warehouse_active num_warehouses
+6 Declarations: x y obj demand warehouse_active num_warehouses
diff --git a/examples/pyomobook/overview-ch/wl_mutable.py b/examples/pyomobook/overview-ch/wl_mutable.py
index e5c4f5e9dbb..8e129dd3c49 100644
--- a/examples/pyomobook/overview-ch/wl_mutable.py
+++ b/examples/pyomobook/overview-ch/wl_mutable.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # wl_mutable.py: warehouse location problem with mutable param
 import pyomo.environ as pyo
 
diff --git a/examples/pyomobook/overview-ch/wl_mutable_excel.py b/examples/pyomobook/overview-ch/wl_mutable_excel.py
index 0906fbb25b3..935fa4963e5 100644
--- a/examples/pyomobook/overview-ch/wl_mutable_excel.py
+++ b/examples/pyomobook/overview-ch/wl_mutable_excel.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # wl_mutable_excel.py: solve problem with different values for P
 import pandas
 import pyomo.environ as pyo
diff --git a/examples/pyomobook/overview-ch/wl_scalar.py b/examples/pyomobook/overview-ch/wl_scalar.py
index ac10fbe8265..6f538baedb8 100644
--- a/examples/pyomobook/overview-ch/wl_scalar.py
+++ b/examples/pyomobook/overview-ch/wl_scalar.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # wl_scalar.py: snippets that show the warehouse location problem implemented as scalar quantities
 import pyomo.environ as pyo
 
diff --git a/examples/pyomobook/performance-ch/SparseSets.py b/examples/pyomobook/performance-ch/SparseSets.py
index 90d097b53aa..519808306de 100644
--- a/examples/pyomobook/performance-ch/SparseSets.py
+++ b/examples/pyomobook/performance-ch/SparseSets.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.AbstractModel()
diff --git a/examples/pyomobook/performance-ch/lin_expr.py b/examples/pyomobook/performance-ch/lin_expr.py
index 75f4e70ec2a..af50ddd6228 100644
--- a/examples/pyomobook/performance-ch/lin_expr.py
+++ b/examples/pyomobook/performance-ch/lin_expr.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 from pyomo.common.timing import TicTocTimer
 from pyomo.core.expr.numeric_expr import LinearExpression
diff --git a/examples/pyomobook/performance-ch/persistent.py b/examples/pyomobook/performance-ch/persistent.py
index 98207909cb6..67f8c656cfe 100644
--- a/examples/pyomobook/performance-ch/persistent.py
+++ b/examples/pyomobook/performance-ch/persistent.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # @model:
 import pyomo.environ as pyo
 
diff --git a/examples/pyomobook/performance-ch/wl.py b/examples/pyomobook/performance-ch/wl.py
index 34c8a73f36e..000f81272a1 100644
--- a/examples/pyomobook/performance-ch/wl.py
+++ b/examples/pyomobook/performance-ch/wl.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # wl.py # define a script to demonstrate performance profiling and improvements
 # @imports:
 import pyomo.environ as pyo  # import pyomo environment
diff --git a/examples/pyomobook/performance-ch/wl.txt b/examples/pyomobook/performance-ch/wl.txt
index f7d2e0ada19..b762acf55cf 100644
--- a/examples/pyomobook/performance-ch/wl.txt
+++ b/examples/pyomobook/performance-ch/wl.txt
@@ -3,94 +3,102 @@ Building model
            0 seconds to construct Block ConcreteModel; 1 index total
            0 seconds to construct Set Any; 1 index total
            0 seconds to construct Param P; 1 index total
+           0 seconds to construct SetOf OrderedSetOf
            0 seconds to construct Set OrderedScalarSet; 1 index total
+           0 seconds to construct SetOf OrderedSetOf
            0 seconds to construct Set OrderedScalarSet; 1 index total
            0 seconds to construct Set SetProduct_OrderedSet; 1 index total
-           0 seconds to construct Set SetProduct_OrderedSet; 1 index total
         0.02 seconds to construct Var x; 40000 indices total
+           0 seconds to construct SetOf OrderedSetOf
            0 seconds to construct Set OrderedScalarSet; 1 index total
            0 seconds to construct Var y; 200 indices total
-        0.13 seconds to construct Objective obj; 1 index total
+        0.14 seconds to construct Objective obj; 1 index total
+           0 seconds to construct SetOf OrderedSetOf
            0 seconds to construct Set OrderedScalarSet; 1 index total
         0.13 seconds to construct Constraint demand; 200 indices total
+           0 seconds to construct SetOf OrderedSetOf
            0 seconds to construct Set OrderedScalarSet; 1 index total
+           0 seconds to construct SetOf OrderedSetOf
            0 seconds to construct Set OrderedScalarSet; 1 index total
            0 seconds to construct Set SetProduct_OrderedSet; 1 index total
-           0 seconds to construct Set SetProduct_OrderedSet; 1 index total
-        0.48 seconds to construct Constraint warehouse_active; 40000 indices total
+        0.50 seconds to construct Constraint warehouse_active; 40000 indices total
            0 seconds to construct Constraint num_warehouses; 1 index total
 Building model with LinearExpression
 ------------------------------------
            0 seconds to construct Block ConcreteModel; 1 index total
            0 seconds to construct Set Any; 1 index total
            0 seconds to construct Param P; 1 index total
+           0 seconds to construct SetOf OrderedSetOf
            0 seconds to construct Set OrderedScalarSet; 1 index total
+           0 seconds to construct SetOf OrderedSetOf
            0 seconds to construct Set OrderedScalarSet; 1 index total
            0 seconds to construct Set SetProduct_OrderedSet; 1 index total
-           0 seconds to construct Set SetProduct_OrderedSet; 1 index total
         0.02 seconds to construct Var x; 40000 indices total
+           0 seconds to construct SetOf OrderedSetOf
            0 seconds to construct Set OrderedScalarSet; 1 index total
            0 seconds to construct Var y; 200 indices total
-        0.06 seconds to construct Objective obj; 1 index total
+        0.20 seconds to construct Objective obj; 1 index total
+           0 seconds to construct SetOf OrderedSetOf
            0 seconds to construct Set OrderedScalarSet; 1 index total
-        0.18 seconds to construct Constraint demand; 200 indices total
+        0.05 seconds to construct Constraint demand; 200 indices total
+           0 seconds to construct SetOf OrderedSetOf
            0 seconds to construct Set OrderedScalarSet; 1 index total
+           0 seconds to construct SetOf OrderedSetOf
            0 seconds to construct Set OrderedScalarSet; 1 index total
            0 seconds to construct Set SetProduct_OrderedSet; 1 index total
-           0 seconds to construct Set SetProduct_OrderedSet; 1 index total
-        0.33 seconds to construct Constraint warehouse_active; 40000 indices total
+        0.34 seconds to construct Constraint warehouse_active; 40000 indices total
            0 seconds to construct Constraint num_warehouses; 1 index total
 [    0.00] start
-[+   0.79] Built model
-[+   2.56] Wrote LP file and solved
-[+  10.96] Finished parameter sweep
-         7372057 function calls (7368345 primitive calls) in 13.627 seconds
+[+   1.00] Built model
+[+   2.28] Wrote LP file and solved
+[+   9.06] Finished parameter sweep
+         7294708 function calls (7291012 primitive calls) in 10.989 seconds
 
    Ordered by: cumulative time
    List reduced from 673 to 15 due to restriction <15>
 
    ncalls  tottime  percall  cumtime  percall filename:lineno(function)
-        1    0.001    0.001   13.627   13.627 /home/jdsiiro/Research/pyomo/examples/pyomobook/performance-ch/wl.py:132(solve_parametric)
-       30    0.002    0.000   13.551    0.452 /home/jdsiiro/Research/pyomo/pyomo/opt/base/solvers.py:530(solve)
-       30    0.001    0.000   10.383    0.346 /home/jdsiiro/Research/pyomo/pyomo/opt/solver/shellcmd.py:247(_apply_solver)
-       30    0.002    0.000   10.381    0.346 /home/jdsiiro/Research/pyomo/pyomo/opt/solver/shellcmd.py:310(_execute_command)
-       30    0.001    0.000   10.360    0.345 /projects/sems/install/rhel7-x86_64/pyomo/compiler/python/3.11.6/lib/python3.11/subprocess.py:506(run)
-       30    0.000    0.000   10.288    0.343 /projects/sems/install/rhel7-x86_64/pyomo/compiler/python/3.11.6/lib/python3.11/subprocess.py:1165(communicate)
-       60    0.000    0.000   10.287    0.171 /projects/sems/install/rhel7-x86_64/pyomo/compiler/python/3.11.6/lib/python3.11/subprocess.py:1259(wait)
-       60    0.001    0.000   10.287    0.171 /projects/sems/install/rhel7-x86_64/pyomo/compiler/python/3.11.6/lib/python3.11/subprocess.py:2014(_wait)
-       30    0.000    0.000   10.286    0.343 /projects/sems/install/rhel7-x86_64/pyomo/compiler/python/3.11.6/lib/python3.11/subprocess.py:2001(_try_wait)
-       30   10.286    0.343   10.286    0.343 {built-in method posix.waitpid}
-       30    0.000    0.000    2.123    0.071 /home/jdsiiro/Research/pyomo/pyomo/solvers/plugins/solvers/GUROBI.py:214(_presolve)
-       30    0.000    0.000    2.122    0.071 /home/jdsiiro/Research/pyomo/pyomo/opt/solver/shellcmd.py:215(_presolve)
-       30    0.000    0.000    2.114    0.070 /home/jdsiiro/Research/pyomo/pyomo/opt/base/solvers.py:687(_presolve)
-       30    0.000    0.000    2.114    0.070 /home/jdsiiro/Research/pyomo/pyomo/opt/base/solvers.py:756(_convert_problem)
-       30    0.001    0.000    2.114    0.070 /home/jdsiiro/Research/pyomo/pyomo/opt/base/convert.py:27(convert_problem)
+        1    0.001    0.001   10.989   10.989 pyomo/examples/pyomobook/performance-ch/wl.py:132(solve_parametric)
+       30    0.002    0.000   10.913    0.364 pyomo/pyomo/opt/base/solvers.py:530(solve)
+       30    0.001    0.000    7.816    0.261 pyomo/pyomo/opt/solver/shellcmd.py:247(_apply_solver)
+       30    0.002    0.000    7.814    0.260 pyomo/pyomo/opt/solver/shellcmd.py:310(_execute_command)
+       30    0.001    0.000    7.793    0.260 /lib/python3.11/subprocess.py:506(run)
+       30    0.000    0.000    7.609    0.254 /lib/python3.11/subprocess.py:1165(communicate)
+       60    0.000    0.000    7.608    0.127 /lib/python3.11/subprocess.py:1259(wait)
+       60    0.000    0.000    7.608    0.127 /lib/python3.11/subprocess.py:2014(_wait)
+       30    0.000    0.000    7.608    0.254 /lib/python3.11/subprocess.py:2001(_try_wait)
+       30    7.607    0.254    7.607    0.254 {built-in method posix.waitpid}
+       30    0.000    0.000    2.166    0.072 pyomo/pyomo/solvers/plugins/solvers/GUROBI.py:214(_presolve)
+       30    0.000    0.000    2.166    0.072 pyomo/pyomo/opt/solver/shellcmd.py:215(_presolve)
+       30    0.000    0.000    2.156    0.072 pyomo/pyomo/opt/base/solvers.py:687(_presolve)
+       30    0.000    0.000    2.156    0.072 pyomo/pyomo/opt/base/solvers.py:754(_convert_problem)
+       30    0.001    0.000    2.156    0.072 pyomo/pyomo/opt/base/convert.py:27(convert_problem)
 
 
 
-         7372057 function calls (7368345 primitive calls) in 13.627 seconds
+         7294708 function calls (7291012 primitive calls) in 10.989 seconds
 
    Ordered by: internal time
    List reduced from 673 to 15 due to restriction <15>
 
    ncalls  tottime  percall  cumtime  percall filename:lineno(function)
-       30   10.286    0.343   10.286    0.343 {built-in method posix.waitpid}
-       30    0.325    0.011    2.078    0.069 /home/jdsiiro/Research/pyomo/pyomo/repn/plugins/lp_writer.py:250(write)
-    76560    0.278    0.000    0.668    0.000 /home/jdsiiro/Research/pyomo/pyomo/repn/plugins/lp_writer.py:576(write_expression)
-       30    0.248    0.008    0.508    0.017 /home/jdsiiro/Research/pyomo/pyomo/solvers/plugins/solvers/GUROBI.py:394(process_soln_file)
-    76560    0.221    0.000    0.395    0.000 /home/jdsiiro/Research/pyomo/pyomo/repn/linear.py:664(_before_linear)
-   301530    0.131    0.000    0.178    0.000 /home/jdsiiro/Research/pyomo/pyomo/core/expr/symbol_map.py:133(getSymbol)
-       30    0.119    0.004    0.192    0.006 /home/jdsiiro/Research/pyomo/pyomo/core/base/PyomoModel.py:461(select)
-    77190    0.117    0.000    0.161    0.000 /home/jdsiiro/Research/pyomo/pyomo/solvers/plugins/solvers/GUROBI.py:451(<listcomp>)
-       30    0.116    0.004    0.285    0.010 /home/jdsiiro/Research/pyomo/pyomo/core/base/PyomoModel.py:337(add_solution)
-    76530    0.080    0.000    0.106    0.000 /home/jdsiiro/Research/pyomo/pyomo/core/expr/symbol_map.py:63(addSymbol)
-   239550    0.079    0.000    0.079    0.000 /home/jdsiiro/Research/pyomo/pyomo/core/base/indexed_component.py:611(__getitem__)
-  1062450    0.078    0.000    0.078    0.000 {built-in method builtins.id}
-   163050    0.074    0.000    0.128    0.000 /home/jdsiiro/Research/pyomo/pyomo/core/base/var.py:1045(__getitem__)
-    76560    0.074    0.000    0.080    0.000 /home/jdsiiro/Research/pyomo/pyomo/repn/linear.py:834(finalizeResult)
-   153150    0.073    0.000    0.191    0.000 /home/jdsiiro/Research/pyomo/pyomo/core/base/block.py:1505(_component_data_itervalues)
+       30    7.607    0.254    7.607    0.254 {built-in method posix.waitpid}
+       30    0.328    0.011    2.101    0.070 pyomo/pyomo/repn/plugins/lp_writer.py:250(write)
+    76560    0.284    0.000    0.680    0.000 pyomo/pyomo/repn/plugins/lp_writer.py:576(write_expression)
+    76560    0.220    0.000    0.388    0.000 pyomo/pyomo/repn/linear.py:664(_before_linear)
+       30    0.209    0.007    0.438    0.015 pyomo/pyomo/solvers/plugins/solvers/GUROBI.py:394(process_soln_file)
+       30    0.175    0.006    0.175    0.006 {built-in method _posixsubprocess.fork_exec}
+   301530    0.134    0.000    0.181    0.000 pyomo/pyomo/core/expr/symbol_map.py:133(getSymbol)
+       30    0.109    0.004    0.178    0.006 pyomo/pyomo/core/base/PyomoModel.py:461(select)
+    77190    0.105    0.000    0.145    0.000 pyomo/pyomo/solvers/plugins/solvers/GUROBI.py:451(<listcomp>)
+       30    0.104    0.003    0.257    0.009 pyomo/pyomo/core/base/PyomoModel.py:337(add_solution)
+    76530    0.081    0.000    0.109    0.000 pyomo/pyomo/core/expr/symbol_map.py:63(addSymbol)
+  1062470    0.079    0.000    0.079    0.000 {built-in method builtins.id}
+    76560    0.073    0.000    0.079    0.000 pyomo/pyomo/repn/linear.py:834(finalizeResult)
+   239550    0.073    0.000    0.073    0.000 pyomo/pyomo/core/base/indexed_component.py:612(__getitem__)
+   153150    0.070    0.000    0.179    0.000 pyomo/pyomo/core/base/block.py:1463(_component_data_itervalues)
 
 
 
 [    0.00] Resetting the tic/toc delta timer
-[+   0.66] Finished parameter sweep with persistent interface
+[+   0.49] Finished parameter sweep with persistent interface
diff --git a/examples/pyomobook/pyomo-components-ch/con_declaration.py b/examples/pyomobook/pyomo-components-ch/con_declaration.py
index 7775c1b26a0..0890ba4771b 100644
--- a/examples/pyomobook/pyomo-components-ch/con_declaration.py
+++ b/examples/pyomobook/pyomo-components-ch/con_declaration.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.ConcreteModel()
diff --git a/examples/pyomobook/pyomo-components-ch/con_declaration.txt b/examples/pyomobook/pyomo-components-ch/con_declaration.txt
index 019cd448eb0..b4709bd5490 100644
--- a/examples/pyomobook/pyomo-components-ch/con_declaration.txt
+++ b/examples/pyomobook/pyomo-components-ch/con_declaration.txt
@@ -1,10 +1,5 @@
-1 Set Declarations
-    x_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    2 : {1, 2}
-
 1 Var Declarations
-    x : Size=2, Index=x_index
+    x : Size=2, Index={1, 2}
         Key : Lower : Value : Upper : Fixed : Stale : Domain
           1 :  None :   1.0 :  None : False : False :  Reals
           2 :  None :   1.0 :  None : False : False :  Reals
@@ -14,14 +9,9 @@
         Key  : Lower : Body        : Upper : Active
         None :  -Inf : x[2] - x[1] :   7.5 :   True
 
-3 Declarations: x_index x diff
-1 Set Declarations
-    x_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    2 : {1, 2}
-
+2 Declarations: x diff
 1 Var Declarations
-    x : Size=2, Index=x_index
+    x : Size=2, Index={1, 2}
         Key : Lower : Value : Upper : Fixed : Stale : Domain
           1 :  None :   1.0 :  None : False : False :  Reals
           2 :  None :   1.0 :  None : False : False :  Reals
@@ -31,40 +21,24 @@
         Key  : Lower : Body        : Upper : Active
         None :  -Inf : x[2] - x[1] :   7.5 :   True
 
-3 Declarations: x_index x diff
-2 Set Declarations
-    CoverConstr_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    3 : {1, 2, 3}
-    y_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    3 : {1, 2, 3}
-
+2 Declarations: x diff
 1 Var Declarations
-    y : Size=3, Index=y_index
+    y : Size=3, Index={1, 2, 3}
         Key : Lower : Value : Upper : Fixed : Stale : Domain
           1 :     0 :   0.0 :  None : False : False : NonNegativeReals
           2 :     0 :   0.0 :  None : False : False : NonNegativeReals
           3 :     0 :   0.0 :  None : False : False : NonNegativeReals
 
 1 Constraint Declarations
-    CoverConstr : Size=3, Index=CoverConstr_index, Active=True
+    CoverConstr : Size=3, Index={1, 2, 3}, Active=True
         Key : Lower : Body     : Upper : Active
           1 :   1.0 :     y[1] :  +Inf :   True
           2 :   2.9 : 3.1*y[2] :  +Inf :   True
           3 :   3.1 : 4.5*y[3] :  +Inf :   True
 
-4 Declarations: y_index y CoverConstr_index CoverConstr
-2 Set Declarations
-    Pred_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    5 : {1, 2, 3, 4, 5}
-    StartTime_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    5 : {1, 2, 3, 4, 5}
-
+2 Declarations: y CoverConstr
 1 Var Declarations
-    StartTime : Size=5, Index=StartTime_index
+    StartTime : Size=5, Index={1, 2, 3, 4, 5}
         Key : Lower : Value : Upper : Fixed : Stale : Domain
           1 :  None :   1.0 :  None : False : False :  Reals
           2 :  None :   1.0 :  None : False : False :  Reals
@@ -73,14 +47,14 @@
           5 :  None :   1.0 :  None : False : False :  Reals
 
 1 Constraint Declarations
-    Pred : Size=4, Index=Pred_index, Active=True
+    Pred : Size=4, Index={1, 2, 3, 4, 5}, Active=True
         Key : Lower : Body                        : Upper : Active
           1 :  -Inf : StartTime[1] - StartTime[2] :   0.0 :   True
           2 :  -Inf : StartTime[2] - StartTime[3] :   0.0 :   True
           3 :  -Inf : StartTime[3] - StartTime[4] :   0.0 :   True
           4 :  -Inf : StartTime[4] - StartTime[5] :   0.0 :   True
 
-4 Declarations: StartTime_index StartTime Pred_index Pred
+2 Declarations: StartTime Pred
 0.0
 inf
 7.5
diff --git a/examples/pyomobook/pyomo-components-ch/examples.py b/examples/pyomobook/pyomo-components-ch/examples.py
index 6ba96792e28..1a59e9e308e 100644
--- a/examples/pyomobook/pyomo-components-ch/examples.py
+++ b/examples/pyomobook/pyomo-components-ch/examples.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 print("indexed1")
diff --git a/examples/pyomobook/pyomo-components-ch/examples.txt b/examples/pyomobook/pyomo-components-ch/examples.txt
index 635b988cbcd..27ea1ba130b 100644
--- a/examples/pyomobook/pyomo-components-ch/examples.txt
+++ b/examples/pyomobook/pyomo-components-ch/examples.txt
@@ -1,20 +1,17 @@
 indexed1
-3 Set Declarations
+2 Set Declarations
     A : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    3 : {1, 2, 3}
     B : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    2 : {'Q', 'R'}
-    y_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    A*B :    6 : {(1, 'Q'), (1, 'R'), (2, 'Q'), (2, 'R'), (3, 'Q'), (3, 'R')}
 
 2 Var Declarations
     x : Size=1, Index=None
         Key  : Lower : Value : Upper : Fixed : Stale : Domain
         None :  None :  None :  None : False :  True :  Reals
-    y : Size=6, Index=y_index
+    y : Size=6, Index=A*B
         Key      : Lower : Value : Upper : Fixed : Stale : Domain
         (1, 'Q') :  None :  None :  None : False :  True :  Reals
         (1, 'R') :  None :  None :  None : False :  True :  Reals
@@ -38,4 +35,4 @@ indexed1
           2 :  -Inf :  2*x :   0.0 :   True
           3 :  -Inf :  3*x :   0.0 :   True
 
-8 Declarations: A B x y_index y o c d
+7 Declarations: A B x y o c d
diff --git a/examples/pyomobook/pyomo-components-ch/expr_declaration.py b/examples/pyomobook/pyomo-components-ch/expr_declaration.py
index 8974a4d406a..da0d854e513 100644
--- a/examples/pyomobook/pyomo-components-ch/expr_declaration.py
+++ b/examples/pyomobook/pyomo-components-ch/expr_declaration.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.ConcreteModel()
diff --git a/examples/pyomobook/pyomo-components-ch/expr_declaration.txt b/examples/pyomobook/pyomo-components-ch/expr_declaration.txt
index 66c99f6502a..86e0feac27f 100644
--- a/examples/pyomobook/pyomo-components-ch/expr_declaration.txt
+++ b/examples/pyomobook/pyomo-components-ch/expr_declaration.txt
@@ -18,28 +18,20 @@
         None : x + 2
 
 3 Declarations: x e1 e2
-2 Set Declarations
-    e_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    3 : {1, 2, 3}
-    x_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    3 : {1, 2, 3}
-
 1 Var Declarations
-    x : Size=3, Index=x_index
+    x : Size=3, Index={1, 2, 3}
         Key : Lower : Value : Upper : Fixed : Stale : Domain
           1 :  None :  None :  None : False :  True :  Reals
           2 :  None :  None :  None : False :  True :  Reals
           3 :  None :  None :  None : False :  True :  Reals
 
 1 Expression Declarations
-    e : Size=2, Index=e_index
+    e : Size=2, Index={1, 2, 3}
         Key : Expression
           2 :    x[2]**2
           3 :    x[3]**2
 
-4 Declarations: x_index x e_index e
+2 Declarations: x e
 1 Var Declarations
     x : Size=1, Index=None
         Key  : Lower : Value : Upper : Fixed : Stale : Domain
diff --git a/examples/pyomobook/pyomo-components-ch/obj_declaration.py b/examples/pyomobook/pyomo-components-ch/obj_declaration.py
index 2c26c2b3363..a63fc441206 100644
--- a/examples/pyomobook/pyomo-components-ch/obj_declaration.py
+++ b/examples/pyomobook/pyomo-components-ch/obj_declaration.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.ConcreteModel()
diff --git a/examples/pyomobook/pyomo-components-ch/obj_declaration.txt b/examples/pyomobook/pyomo-components-ch/obj_declaration.txt
index e43134b8d92..e4d4b02a252 100644
--- a/examples/pyomobook/pyomo-components-ch/obj_declaration.txt
+++ b/examples/pyomobook/pyomo-components-ch/obj_declaration.txt
@@ -14,7 +14,7 @@ declexprrule
 Model unknown
 
   Variables:
-    x : Size=2, Index=x_index
+    x : Size=2, Index={1, 2}
         Key : Lower : Value : Upper : Fixed : Stale : Domain
           1 :  None :   1.0 :  None : False : False :  Reals
           2 :  None :   1.0 :  None : False : False :  Reals
@@ -34,19 +34,19 @@ declskip
 Model unknown
 
   Variables:
-    x : Size=3, Index=x_index
+    x : Size=3, Index={Q, R, S}
         Key : Lower : Value : Upper : Fixed : Stale : Domain
           Q :  None :   1.0 :  None : False : False :  Reals
           R :  None :   1.0 :  None : False : False :  Reals
           S :  None :   1.0 :  None : False : False :  Reals
 
   Objectives:
-    d : Size=3, Index=d_index, Active=True
+    d : Size=3, Index={Q, R, S}, Active=True
         Key : Active : Value
           Q :   True :   1.0
           R :   True :   1.0
           S :   True :   1.0
-    e : Size=2, Index=e_index, Active=True
+    e : Size=2, Index={Q, R, S}, Active=True
         Key : Active : Value
           Q :   True :   1.0
           S :   True :   1.0
@@ -55,12 +55,12 @@ Model unknown
     None
 value
 x[Q] + 2*x[R]
-1
+minimize
 6.5
 Model unknown
 
   Variables:
-    x : Size=2, Index=x_index
+    x : Size=2, Index={Q, R}
         Key : Lower : Value : Upper : Fixed : Stale : Domain
           Q :  None :   1.5 :  None : False : False :  Reals
           R :  None :   2.5 :  None : False : False :  Reals
diff --git a/examples/pyomobook/pyomo-components-ch/param_declaration.py b/examples/pyomobook/pyomo-components-ch/param_declaration.py
index a9d3256abfe..98b16548c28 100644
--- a/examples/pyomobook/pyomo-components-ch/param_declaration.py
+++ b/examples/pyomobook/pyomo-components-ch/param_declaration.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.ConcreteModel()
diff --git a/examples/pyomobook/pyomo-components-ch/param_declaration.txt b/examples/pyomobook/pyomo-components-ch/param_declaration.txt
index 9b8ce9cacdb..8c8a49eedc6 100644
--- a/examples/pyomobook/pyomo-components-ch/param_declaration.txt
+++ b/examples/pyomobook/pyomo-components-ch/param_declaration.txt
@@ -1,16 +1,13 @@
-3 Set Declarations
+2 Set Declarations
     A : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    3 : {1, 2, 3}
     B : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    2 : {'A', 'B'}
-    T_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    A*B :    6 : {(1, 'A'), (1, 'B'), (2, 'A'), (2, 'B'), (3, 'A'), (3, 'B')}
 
 3 Param Declarations
-    T : Size=3, Index=T_index, Domain=Any, Default=None, Mutable=False
+    T : Size=3, Index=A*B, Domain=Any, Default=None, Mutable=False
         Key      : Value
         (1, 'A') :    10
         (2, 'B') :    20
@@ -24,4 +21,4 @@
         Key  : Value
         None :    32
 
-6 Declarations: Z A B U T_index T
+5 Declarations: Z A B U T
diff --git a/examples/pyomobook/pyomo-components-ch/param_initialization.py b/examples/pyomobook/pyomo-components-ch/param_initialization.py
index 11c257d2c31..88da8a68354 100644
--- a/examples/pyomobook/pyomo-components-ch/param_initialization.py
+++ b/examples/pyomobook/pyomo-components-ch/param_initialization.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.ConcreteModel()
diff --git a/examples/pyomobook/pyomo-components-ch/param_initialization.txt b/examples/pyomobook/pyomo-components-ch/param_initialization.txt
index d1ac6aba989..e0bcdf11a71 100644
--- a/examples/pyomobook/pyomo-components-ch/param_initialization.txt
+++ b/examples/pyomobook/pyomo-components-ch/param_initialization.txt
@@ -1,27 +1,15 @@
-6 Set Declarations
+2 Set Declarations
     A : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    3 : {1, 2, 3}
     B : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    3 : {1, 2, 3}
-    T_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    A*B :    9 : {(1, 1), (1, 2), (1, 3), (2, 1), (2, 2), (2, 3), (3, 1), (3, 2), (3, 3)}
-    U_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    A*A :    9 : {(1, 1), (1, 2), (1, 3), (2, 1), (2, 2), (2, 3), (3, 1), (3, 2), (3, 3)}
-    XX_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    A*A :    9 : {(1, 1), (1, 2), (1, 3), (2, 1), (2, 2), (2, 3), (3, 1), (3, 2), (3, 3)}
-    X_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    A*A :    9 : {(1, 1), (1, 2), (1, 3), (2, 1), (2, 2), (2, 3), (3, 1), (3, 2), (3, 3)}
 
 5 Param Declarations
-    T : Size=0, Index=T_index, Domain=Any, Default=None, Mutable=False
+    T : Size=0, Index=A*B, Domain=Any, Default=None, Mutable=False
         Key : Value
-    U : Size=9, Index=U_index, Domain=Any, Default=0, Mutable=False
+    U : Size=9, Index=A*A, Domain=Any, Default=0, Mutable=False
         Key    : Value
         (1, 1) :    10
         (2, 2) :    20
@@ -30,7 +18,7 @@
         Key : Value
           1 :    10
           3 :    30
-    X : Size=9, Index=X_index, Domain=Any, Default=None, Mutable=False
+    X : Size=9, Index=A*A, Domain=Any, Default=None, Mutable=False
         Key    : Value
         (1, 1) :     1
         (1, 2) :     2
@@ -41,7 +29,7 @@
         (3, 1) :     3
         (3, 2) :     6
         (3, 3) :     9
-    XX : Size=9, Index=XX_index, Domain=Any, Default=None, Mutable=False
+    XX : Size=9, Index=A*A, Domain=Any, Default=None, Mutable=False
         Key    : Value
         (1, 1) :     1
         (1, 2) :     2
@@ -53,7 +41,7 @@
         (3, 2) :     8
         (3, 3) :    14
 
-11 Declarations: A X_index X XX_index XX B W U_index U T_index T
+7 Declarations: A X XX B W U T
 2
 3
 False
diff --git a/examples/pyomobook/pyomo-components-ch/param_misc.py b/examples/pyomobook/pyomo-components-ch/param_misc.py
index baf76cc7c03..72fca60f787 100644
--- a/examples/pyomobook/pyomo-components-ch/param_misc.py
+++ b/examples/pyomobook/pyomo-components-ch/param_misc.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 # @mutable1:
diff --git a/examples/pyomobook/pyomo-components-ch/param_validation.py b/examples/pyomobook/pyomo-components-ch/param_validation.py
index c82657c8d0f..baf5f0ac1e2 100644
--- a/examples/pyomobook/pyomo-components-ch/param_validation.py
+++ b/examples/pyomobook/pyomo-components-ch/param_validation.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.AbstractModel()
diff --git a/examples/pyomobook/pyomo-components-ch/rangeset.py b/examples/pyomobook/pyomo-components-ch/rangeset.py
index d5e1015064c..169060e9ab2 100644
--- a/examples/pyomobook/pyomo-components-ch/rangeset.py
+++ b/examples/pyomobook/pyomo-components-ch/rangeset.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.AbstractModel()
diff --git a/examples/pyomobook/pyomo-components-ch/set_declaration.py b/examples/pyomobook/pyomo-components-ch/set_declaration.py
index 1a507d4f588..bf3cfa1be15 100644
--- a/examples/pyomobook/pyomo-components-ch/set_declaration.py
+++ b/examples/pyomobook/pyomo-components-ch/set_declaration.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.AbstractModel()
diff --git a/examples/pyomobook/pyomo-components-ch/set_declaration.txt b/examples/pyomobook/pyomo-components-ch/set_declaration.txt
index bdbb7376de4..a588e5601b6 100644
--- a/examples/pyomobook/pyomo-components-ch/set_declaration.txt
+++ b/examples/pyomobook/pyomo-components-ch/set_declaration.txt
@@ -5,22 +5,16 @@
 
 1 Declarations: A
 0 Declarations: 
-4 Set Declarations
-    E : Size=1, Index=E_index, Ordered=Insertion
+2 Set Declarations
+    E : Size=1, Index={1, 2, 3}, Ordered=Insertion
         Key : Dimen : Domain : Size : Members
           2 :     1 :    Any :    3 : {21, 22, 23}
-    E_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    3 : {1, 2, 3}
-    F : Size=2, Index=F_index, Ordered=Insertion
+    F : Size=2, Index={1, 2, 3}, Ordered=Insertion
         Key : Dimen : Domain : Size : Members
           1 :     1 :    Any :    3 : {11, 12, 13}
           3 :     1 :    Any :    3 : {31, 32, 33}
-    F_index : Size=1, Index=None, Ordered=False
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    3 : {1, 2, 3}
 
-4 Declarations: E_index E F_index F
+2 Declarations: E F
 6 Set Declarations
     A : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
diff --git a/examples/pyomobook/pyomo-components-ch/set_initialization.py b/examples/pyomobook/pyomo-components-ch/set_initialization.py
index 89dbaa713db..bdfd662c985 100644
--- a/examples/pyomobook/pyomo-components-ch/set_initialization.py
+++ b/examples/pyomobook/pyomo-components-ch/set_initialization.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.ConcreteModel()
diff --git a/examples/pyomobook/pyomo-components-ch/set_initialization.txt b/examples/pyomobook/pyomo-components-ch/set_initialization.txt
index af2ba54a8d2..29900ccb7b2 100644
--- a/examples/pyomobook/pyomo-components-ch/set_initialization.txt
+++ b/examples/pyomobook/pyomo-components-ch/set_initialization.txt
@@ -1,19 +1,16 @@
-10 Set Declarations
+7 Set Declarations
     B : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    3 : {2, 3, 4}
     C : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     2 :    Any :    2 : {(1, 4), (9, 16)}
-    F : Size=3, Index=F_index, Ordered=Insertion
+    F : Size=3, Index={2, 3, 4}, Ordered=Insertion
         Key : Dimen : Domain : Size : Members
           2 :     1 :    Any :    3 : {1, 3, 5}
           3 :     1 :    Any :    3 : {2, 4, 6}
           4 :     1 :    Any :    3 : {3, 5, 7}
-    F_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    3 : {2, 3, 4}
-    J : Size=9, Index=J_index, Ordered=Insertion
+    J : Size=9, Index=B*B, Ordered=Insertion
         Key    : Dimen : Domain : Size : Members
         (2, 2) :     1 :    Any :    4 : {0, 1, 2, 3}
         (2, 3) :     1 :    Any :    6 : {0, 1, 2, 3, 4, 5}
@@ -24,21 +21,15 @@
         (4, 2) :     1 :    Any :    8 : {0, 1, 2, 3, 4, 5, 6, 7}
         (4, 3) :     1 :    Any :   12 : {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11}
         (4, 4) :     1 :    Any :   16 : {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}
-    J_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    B*B :    9 : {(2, 2), (2, 3), (2, 4), (3, 2), (3, 3), (3, 4), (4, 2), (4, 3), (4, 4)}
     P : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    5 : {1, 2, 3, 5, 7}
     Q : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    4 : {4, 6, 8, 9}
-    R : Size=2, Index=R_index, Ordered=Insertion
+    R : Size=2, Index={1, 2, 3}, Ordered=Insertion
         Key : Dimen : Domain : Size : Members
           1 :     1 :    Any :    1 : {1,}
           2 :     1 :    Any :    2 : {1, 2}
-    R_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    3 : {1, 2, 3}
 
-10 Declarations: B C F_index F J_index J P Q R_index R
+7 Declarations: B C F J P Q R
diff --git a/examples/pyomobook/pyomo-components-ch/set_misc.py b/examples/pyomobook/pyomo-components-ch/set_misc.py
index 9a795b196b8..20ed9518f52 100644
--- a/examples/pyomobook/pyomo-components-ch/set_misc.py
+++ b/examples/pyomobook/pyomo-components-ch/set_misc.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.ConcreteModel()
diff --git a/examples/pyomobook/pyomo-components-ch/set_options.py b/examples/pyomobook/pyomo-components-ch/set_options.py
index 8d49882de2f..30c0b49706d 100644
--- a/examples/pyomobook/pyomo-components-ch/set_options.py
+++ b/examples/pyomobook/pyomo-components-ch/set_options.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.AbstractModel()
diff --git a/examples/pyomobook/pyomo-components-ch/set_validation.py b/examples/pyomobook/pyomo-components-ch/set_validation.py
index a55dfc9ab7c..2300c0be693 100644
--- a/examples/pyomobook/pyomo-components-ch/set_validation.py
+++ b/examples/pyomobook/pyomo-components-ch/set_validation.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.AbstractModel()
diff --git a/examples/pyomobook/pyomo-components-ch/suffix_declaration.py b/examples/pyomobook/pyomo-components-ch/suffix_declaration.py
index 650669ef5a6..619093712f1 100644
--- a/examples/pyomobook/pyomo-components-ch/suffix_declaration.py
+++ b/examples/pyomobook/pyomo-components-ch/suffix_declaration.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 print('')
diff --git a/examples/pyomobook/pyomo-components-ch/var_declaration.py b/examples/pyomobook/pyomo-components-ch/var_declaration.py
index 60d3b00756a..2ee5d7fb749 100644
--- a/examples/pyomobook/pyomo-components-ch/var_declaration.py
+++ b/examples/pyomobook/pyomo-components-ch/var_declaration.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.ConcreteModel()
diff --git a/examples/pyomobook/python-ch/BadIndent.py b/examples/pyomobook/python-ch/BadIndent.py
index 6ab545a6f46..4a00cae12ef 100644
--- a/examples/pyomobook/python-ch/BadIndent.py
+++ b/examples/pyomobook/python-ch/BadIndent.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # This comment is the first line of BadIndent.py,
 # which will cause Python to give an error message
 # concerning indentation.
diff --git a/examples/pyomobook/python-ch/LineExample.py b/examples/pyomobook/python-ch/LineExample.py
index 0109a64167e..31cface5760 100644
--- a/examples/pyomobook/python-ch/LineExample.py
+++ b/examples/pyomobook/python-ch/LineExample.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # This comment is the first line of LineExample.py
 # all characters on a line after the #-character are
 # ignored by Python
diff --git a/examples/pyomobook/python-ch/class.py b/examples/pyomobook/python-ch/class.py
index 562cef07ea7..a09f991d37b 100644
--- a/examples/pyomobook/python-ch/class.py
+++ b/examples/pyomobook/python-ch/class.py
@@ -1,25 +1,36 @@
-# class.py
-
-
-# @all:
-class IntLocker:
-    sint = None
-
-    def __init__(self, i):
-        self.set_value(i)
-
-    def set_value(self, i):
-        if type(i) is not int:
-            print("Error: %d is not integer." % i)
-        else:
-            self.sint = i
-
-    def pprint(self):
-        print("The Int Locker has " + str(self.sint))
-
-
-a = IntLocker(3)
-a.pprint()  # prints: The Int Locker has 3
-a.set_value(5)
-a.pprint()  # prints: The Int Locker has 5
-# @:all
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+# class.py
+
+
+# @all:
+class IntLocker:
+    sint = None
+
+    def __init__(self, i):
+        self.set_value(i)
+
+    def set_value(self, i):
+        if type(i) is not int:
+            print("Error: %d is not integer." % i)
+        else:
+            self.sint = i
+
+    def pprint(self):
+        print("The Int Locker has " + str(self.sint))
+
+
+a = IntLocker(3)
+a.pprint()  # prints: The Int Locker has 3
+a.set_value(5)
+a.pprint()  # prints: The Int Locker has 5
+# @:all
diff --git a/examples/pyomobook/python-ch/ctob.py b/examples/pyomobook/python-ch/ctob.py
index e418d27f103..8945e4863de 100644
--- a/examples/pyomobook/python-ch/ctob.py
+++ b/examples/pyomobook/python-ch/ctob.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # An example of a silly decorator to change 'c' to 'b'
 # in the return value of a function.
 
diff --git a/examples/pyomobook/python-ch/example.py b/examples/pyomobook/python-ch/example.py
index 0a404add58d..184153545a3 100644
--- a/examples/pyomobook/python-ch/example.py
+++ b/examples/pyomobook/python-ch/example.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # This is a comment line, which is ignored by Python
 
 print("Hello World")
diff --git a/examples/pyomobook/python-ch/example2.py b/examples/pyomobook/python-ch/example2.py
index da7d14e24ae..9a6a28bedbd 100644
--- a/examples/pyomobook/python-ch/example2.py
+++ b/examples/pyomobook/python-ch/example2.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # A modified example.py program
 print("Hello World")
 
diff --git a/examples/pyomobook/python-ch/functions.py b/examples/pyomobook/python-ch/functions.py
index 7948c5e55df..97fb77edbe4 100644
--- a/examples/pyomobook/python-ch/functions.py
+++ b/examples/pyomobook/python-ch/functions.py
@@ -1,24 +1,35 @@
-# functions.py
-
-
-# @all:
-def Apply(f, a):
-    r = []
-    for i in range(len(a)):
-        r.append(f(a[i]))
-    return r
-
-
-def SqifOdd(x):
-    # if x is odd, 2*int(x/2) is not x
-    # due to integer divide of x/2
-    if 2 * int(x / 2) == x:
-        return x
-    else:
-        return x * x
-
-
-ShortList = range(4)
-B = Apply(SqifOdd, ShortList)
-print(B)
-# @:all
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+# functions.py
+
+
+# @all:
+def Apply(f, a):
+    r = []
+    for i in range(len(a)):
+        r.append(f(a[i]))
+    return r
+
+
+def SqifOdd(x):
+    # if x is odd, 2*int(x/2) is not x
+    # due to integer divide of x/2
+    if 2 * int(x / 2) == x:
+        return x
+    else:
+        return x * x
+
+
+ShortList = range(4)
+B = Apply(SqifOdd, ShortList)
+print(B)
+# @:all
diff --git a/examples/pyomobook/python-ch/iterate.py b/examples/pyomobook/python-ch/iterate.py
index 3a3422b2a09..50d74f93da7 100644
--- a/examples/pyomobook/python-ch/iterate.py
+++ b/examples/pyomobook/python-ch/iterate.py
@@ -1,18 +1,29 @@
-# iterate.py
-
-# @all:
-D = {'Mary': 231}
-D['Bob'] = 123
-D['Alice'] = 331
-D['Ted'] = 987
-
-for i in sorted(D):
-    if i == 'Alice':
-        continue
-    if i == 'John':
-        print("Loop ends. Cleese alert!")
-        break
-    print(i + " " + str(D[i]))
-else:
-    print("Cleese is not in the list.")
-# @:all
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+# iterate.py
+
+# @all:
+D = {'Mary': 231}
+D['Bob'] = 123
+D['Alice'] = 331
+D['Ted'] = 987
+
+for i in sorted(D):
+    if i == 'Alice':
+        continue
+    if i == 'John':
+        print("Loop ends. Cleese alert!")
+        break
+    print(i + " " + str(D[i]))
+else:
+    print("Cleese is not in the list.")
+# @:all
diff --git a/examples/pyomobook/python-ch/pythonconditional.py b/examples/pyomobook/python-ch/pythonconditional.py
index 205428e5ad1..a39e148622b 100644
--- a/examples/pyomobook/python-ch/pythonconditional.py
+++ b/examples/pyomobook/python-ch/pythonconditional.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # pythonconditional.py
 
 # @all:
diff --git a/examples/pyomobook/scripts-ch/attributes.py b/examples/pyomobook/scripts-ch/attributes.py
index 643162082b6..c406bbf3e1c 100644
--- a/examples/pyomobook/scripts-ch/attributes.py
+++ b/examples/pyomobook/scripts-ch/attributes.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import json
 import pyomo.environ as pyo
 from warehouse_model import create_wl_model
diff --git a/examples/pyomobook/scripts-ch/prob_mod_ex.py b/examples/pyomobook/scripts-ch/prob_mod_ex.py
index 6d610e9b44a..dceafe9d4f0 100644
--- a/examples/pyomobook/scripts-ch/prob_mod_ex.py
+++ b/examples/pyomobook/scripts-ch/prob_mod_ex.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.ConcreteModel()
diff --git a/examples/pyomobook/scripts-ch/sudoku/sudoku.py b/examples/pyomobook/scripts-ch/sudoku/sudoku.py
index ea0c0044e1d..8aa39f91203 100644
--- a/examples/pyomobook/scripts-ch/sudoku/sudoku.py
+++ b/examples/pyomobook/scripts-ch/sudoku/sudoku.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 # create a standard python dict for mapping subsquares to
diff --git a/examples/pyomobook/scripts-ch/sudoku/sudoku_run.py b/examples/pyomobook/scripts-ch/sudoku/sudoku_run.py
index 266362308fa..b3f861f86b5 100644
--- a/examples/pyomobook/scripts-ch/sudoku/sudoku_run.py
+++ b/examples/pyomobook/scripts-ch/sudoku/sudoku_run.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.opt import SolverFactory, TerminationCondition
 from sudoku import create_sudoku_model, print_solution, add_integer_cut
 
diff --git a/examples/pyomobook/scripts-ch/value_expression.py b/examples/pyomobook/scripts-ch/value_expression.py
index 51c07500ea8..00c79fec501 100644
--- a/examples/pyomobook/scripts-ch/value_expression.py
+++ b/examples/pyomobook/scripts-ch/value_expression.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 model = pyo.ConcreteModel()
diff --git a/examples/pyomobook/scripts-ch/warehouse_cuts.py b/examples/pyomobook/scripts-ch/warehouse_cuts.py
index c6516e796af..345dc5540cb 100644
--- a/examples/pyomobook/scripts-ch/warehouse_cuts.py
+++ b/examples/pyomobook/scripts-ch/warehouse_cuts.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import warnings
 
 warnings.filterwarnings("ignore")
diff --git a/examples/pyomobook/scripts-ch/warehouse_cuts.txt b/examples/pyomobook/scripts-ch/warehouse_cuts.txt
index 9afe6c4e944..1f097e06cea 100644
--- a/examples/pyomobook/scripts-ch/warehouse_cuts.txt
+++ b/examples/pyomobook/scripts-ch/warehouse_cuts.txt
@@ -1,7 +1,7 @@
 
 --- Solver Status: optimal ---
 Optimal Obj. Value = 2745.0
-y : Size=3, Index=y_index
+y : Size=3, Index={Harlingen, Memphis, Ashland}
     Key       : Lower : Value : Upper : Fixed : Stale : Domain
       Ashland :     0 :   1.0 :     1 : False : False : Binary
     Harlingen :     0 :   1.0 :     1 : False : False : Binary
@@ -9,7 +9,7 @@ y : Size=3, Index=y_index
 
 --- Solver Status: optimal ---
 Optimal Obj. Value = 3168.0
-y : Size=3, Index=y_index
+y : Size=3, Index={Harlingen, Memphis, Ashland}
     Key       : Lower : Value : Upper : Fixed : Stale : Domain
       Ashland :     0 :   1.0 :     1 : False : False : Binary
     Harlingen :     0 :   0.0 :     1 : False : False : Binary
@@ -17,7 +17,7 @@ y : Size=3, Index=y_index
 
 --- Solver Status: optimal ---
 Optimal Obj. Value = 3563.0
-y : Size=3, Index=y_index
+y : Size=3, Index={Harlingen, Memphis, Ashland}
     Key       : Lower : Value : Upper : Fixed : Stale : Domain
       Ashland :     0 :   0.0 :     1 : False : False : Binary
     Harlingen :     0 :   1.0 :     1 : False : False : Binary
@@ -25,7 +25,7 @@ y : Size=3, Index=y_index
 
 --- Solver Status: optimal ---
 Optimal Obj. Value = 3986.0
-y : Size=3, Index=y_index
+y : Size=3, Index={Harlingen, Memphis, Ashland}
     Key       : Lower : Value : Upper : Fixed : Stale : Domain
       Ashland :     0 :   0.0 :     1 : False : False : Binary
     Harlingen :     0 :   0.0 :     1 : False : False : Binary
@@ -33,7 +33,7 @@ y : Size=3, Index=y_index
 
 --- Solver Status: optimal ---
 Optimal Obj. Value = 4367.0
-y : Size=3, Index=y_index
+y : Size=3, Index={Harlingen, Memphis, Ashland}
     Key       : Lower : Value : Upper : Fixed : Stale : Domain
       Ashland :     0 :   1.0 :     1 : False : False : Binary
     Harlingen :     0 :   0.0 :     1 : False : False : Binary
@@ -41,7 +41,7 @@ y : Size=3, Index=y_index
 
 --- Solver Status: optimal ---
 Optimal Obj. Value = 5302.0
-y : Size=3, Index=y_index
+y : Size=3, Index={Harlingen, Memphis, Ashland}
     Key       : Lower : Value : Upper : Fixed : Stale : Domain
       Ashland :     0 :   0.0 :     1 : False : False : Binary
     Harlingen :     0 :   1.0 :     1 : False : False : Binary
diff --git a/examples/pyomobook/scripts-ch/warehouse_load_solutions.py b/examples/pyomobook/scripts-ch/warehouse_load_solutions.py
index 790333a0e64..d38412f84df 100644
--- a/examples/pyomobook/scripts-ch/warehouse_load_solutions.py
+++ b/examples/pyomobook/scripts-ch/warehouse_load_solutions.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import json
 import pyomo.environ as pyo
 from warehouse_model import create_wl_model
diff --git a/examples/pyomobook/scripts-ch/warehouse_model.py b/examples/pyomobook/scripts-ch/warehouse_model.py
index f5983d3cd89..149eb212759 100644
--- a/examples/pyomobook/scripts-ch/warehouse_model.py
+++ b/examples/pyomobook/scripts-ch/warehouse_model.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 
 
diff --git a/examples/pyomobook/scripts-ch/warehouse_print.py b/examples/pyomobook/scripts-ch/warehouse_print.py
index e0e2f961345..8c862506bf0 100644
--- a/examples/pyomobook/scripts-ch/warehouse_print.py
+++ b/examples/pyomobook/scripts-ch/warehouse_print.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import json
 import pyomo.environ as pyo
 from warehouse_model import create_wl_model
diff --git a/examples/pyomobook/scripts-ch/warehouse_script.py b/examples/pyomobook/scripts-ch/warehouse_script.py
index f2635a45d3d..617b8036abf 100644
--- a/examples/pyomobook/scripts-ch/warehouse_script.py
+++ b/examples/pyomobook/scripts-ch/warehouse_script.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # @script:
 import json
 import pyomo.environ as pyo
diff --git a/examples/pyomobook/scripts-ch/warehouse_script.txt b/examples/pyomobook/scripts-ch/warehouse_script.txt
index b922643dd2b..fac3aef0880 100644
--- a/examples/pyomobook/scripts-ch/warehouse_script.txt
+++ b/examples/pyomobook/scripts-ch/warehouse_script.txt
@@ -1,36 +1,10 @@
-y : Size=3, Index=y_index
+y : Size=3, Index={Harlingen, Memphis, Ashland}
     Key       : Lower : Value : Upper : Fixed : Stale : Domain
       Ashland :     0 :   1.0 :     1 : False : False : Binary
     Harlingen :     0 :   1.0 :     1 : False : False : Binary
       Memphis :     0 :   0.0 :     1 : False : False : Binary
-8 Set Declarations
-    one_per_cust_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    4 : {'NYC', 'LA', 'Chicago', 'Houston'}
-    warehouse_active_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain                                            : Size : Members
-        None :     2 : warehouse_active_index_0*warehouse_active_index_1 :   12 : {('Harlingen', 'NYC'), ('Harlingen', 'LA'), ('Harlingen', 'Chicago'), ('Harlingen', 'Houston'), ('Memphis', 'NYC'), ('Memphis', 'LA'), ('Memphis', 'Chicago'), ('Memphis', 'Houston'), ('Ashland', 'NYC'), ('Ashland', 'LA'), ('Ashland', 'Chicago'), ('Ashland', 'Houston')}
-    warehouse_active_index_0 : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    3 : {'Harlingen', 'Memphis', 'Ashland'}
-    warehouse_active_index_1 : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    4 : {'NYC', 'LA', 'Chicago', 'Houston'}
-    x_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain              : Size : Members
-        None :     2 : x_index_0*x_index_1 :   12 : {('Harlingen', 'NYC'), ('Harlingen', 'LA'), ('Harlingen', 'Chicago'), ('Harlingen', 'Houston'), ('Memphis', 'NYC'), ('Memphis', 'LA'), ('Memphis', 'Chicago'), ('Memphis', 'Houston'), ('Ashland', 'NYC'), ('Ashland', 'LA'), ('Ashland', 'Chicago'), ('Ashland', 'Houston')}
-    x_index_0 : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    3 : {'Harlingen', 'Memphis', 'Ashland'}
-    x_index_1 : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    4 : {'NYC', 'LA', 'Chicago', 'Houston'}
-    y_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    3 : {'Harlingen', 'Memphis', 'Ashland'}
-
 2 Var Declarations
-    x : Size=12, Index=x_index
+    x : Size=12, Index={Harlingen, Memphis, Ashland}*{NYC, LA, Chicago, Houston}
         Key                      : Lower : Value : Upper : Fixed : Stale : Domain
           ('Ashland', 'Chicago') :     0 :   1.0 :     1 : False : False :  Reals
           ('Ashland', 'Houston') :     0 :   0.0 :     1 : False : False :  Reals
@@ -40,11 +14,11 @@ y : Size=3, Index=y_index
         ('Harlingen', 'Houston') :     0 :   1.0 :     1 : False : False :  Reals
              ('Harlingen', 'LA') :     0 :   1.0 :     1 : False : False :  Reals
             ('Harlingen', 'NYC') :     0 :   0.0 :     1 : False : False :  Reals
-          ('Memphis', 'Chicago') :     0 :  -0.0 :     1 : False : False :  Reals
+          ('Memphis', 'Chicago') :     0 :   0.0 :     1 : False : False :  Reals
           ('Memphis', 'Houston') :     0 :   0.0 :     1 : False : False :  Reals
                ('Memphis', 'LA') :     0 :   0.0 :     1 : False : False :  Reals
               ('Memphis', 'NYC') :     0 :   0.0 :     1 : False : False :  Reals
-    y : Size=3, Index=y_index
+    y : Size=3, Index={Harlingen, Memphis, Ashland}
         Key       : Lower : Value : Upper : Fixed : Stale : Domain
           Ashland :     0 :   1.0 :     1 : False : False : Binary
         Harlingen :     0 :   1.0 :     1 : False : False : Binary
@@ -59,13 +33,13 @@ y : Size=3, Index=y_index
     num_warehouses : Size=1, Index=None, Active=True
         Key  : Lower : Body                                   : Upper : Active
         None :  -Inf : y[Harlingen] + y[Memphis] + y[Ashland] :   2.0 :   True
-    one_per_cust : Size=4, Index=one_per_cust_index, Active=True
+    one_per_cust : Size=4, Index={NYC, LA, Chicago, Houston}, Active=True
         Key     : Lower : Body                                                           : Upper : Active
         Chicago :   1.0 : x[Harlingen,Chicago] + x[Memphis,Chicago] + x[Ashland,Chicago] :   1.0 :   True
         Houston :   1.0 : x[Harlingen,Houston] + x[Memphis,Houston] + x[Ashland,Houston] :   1.0 :   True
              LA :   1.0 :                x[Harlingen,LA] + x[Memphis,LA] + x[Ashland,LA] :   1.0 :   True
             NYC :   1.0 :             x[Harlingen,NYC] + x[Memphis,NYC] + x[Ashland,NYC] :   1.0 :   True
-    warehouse_active : Size=12, Index=warehouse_active_index, Active=True
+    warehouse_active : Size=12, Index={Harlingen, Memphis, Ashland}*{NYC, LA, Chicago, Houston}, Active=True
         Key                      : Lower : Body                                : Upper : Active
           ('Ashland', 'Chicago') :  -Inf :     x[Ashland,Chicago] - y[Ashland] :   0.0 :   True
           ('Ashland', 'Houston') :  -Inf :     x[Ashland,Houston] - y[Ashland] :   0.0 :   True
@@ -80,4 +54,4 @@ y : Size=3, Index=y_index
                ('Memphis', 'LA') :  -Inf :          x[Memphis,LA] - y[Memphis] :   0.0 :   True
               ('Memphis', 'NYC') :  -Inf :         x[Memphis,NYC] - y[Memphis] :   0.0 :   True
 
-14 Declarations: x_index_0 x_index_1 x_index x y_index y obj one_per_cust_index one_per_cust warehouse_active_index_0 warehouse_active_index_1 warehouse_active_index warehouse_active num_warehouses
+6 Declarations: x y obj one_per_cust warehouse_active num_warehouses
diff --git a/examples/pyomobook/scripts-ch/warehouse_solver_options.py b/examples/pyomobook/scripts-ch/warehouse_solver_options.py
index c8eaf11a0f3..4e79e158d50 100644
--- a/examples/pyomobook/scripts-ch/warehouse_solver_options.py
+++ b/examples/pyomobook/scripts-ch/warehouse_solver_options.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # @script:
 import json
 import pyomo.environ as pyo
diff --git a/examples/pyomobook/strip_examples.py b/examples/pyomobook/strip_examples.py
index 0a65eef7c04..84017299fb6 100644
--- a/examples/pyomobook/strip_examples.py
+++ b/examples/pyomobook/strip_examples.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import glob
 import sys
 import os
diff --git a/examples/pyomobook/test_book_examples.py b/examples/pyomobook/test_book_examples.py
index e946864c1aa..192330dc1bf 100644
--- a/examples/pyomobook/test_book_examples.py
+++ b/examples/pyomobook/test_book_examples.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/__future__.py b/pyomo/__future__.py
new file mode 100644
index 00000000000..d298e12cab6
--- /dev/null
+++ b/pyomo/__future__.py
@@ -0,0 +1,118 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import pyomo.environ as _environ
+
+__doc__ = """
+Preview capabilities through ``pyomo.__future__``
+=================================================
+
+This module provides a uniform interface for gaining access to future
+("preview") capabilities that are either slightly incompatible with the
+current official offering, or are still under development with the
+intent to replace the current offering.
+
+Currently supported ``__future__`` offerings include:
+
+.. autosummary::
+
+   solver_factory
+
+.. autofunction:: solver_factory
+
+"""
+
+
+def __getattr__(name):
+    if name in ('solver_factory_v1', 'solver_factory_v2', 'solver_factory_v3'):
+        return solver_factory(int(name[-1]))
+    raise AttributeError(f"module '{__name__}' has no attribute '{name}'")
+
+
+def solver_factory(version=None):
+    """Get (or set) the active implementation of the SolverFactory
+
+    This allows users to query / set the current implementation of the
+    SolverFactory that should be used throughout Pyomo.  Valid options are:
+
+    - ``1``: the original Pyomo SolverFactory
+    - ``2``: the SolverFactory from APPSI
+    - ``3``: the SolverFactory from pyomo.contrib.solver
+
+    The current active version can be obtained by calling the method
+    with no arguments
+
+    .. doctest::
+
+        >>> from pyomo.__future__ import solver_factory
+        >>> solver_factory()
+        1
+
+    The active factory can be set either by passing the appropriate
+    version to this function:
+
+    .. doctest::
+
+        >>> solver_factory(3)
+        <pyomo.contrib.solver.factory.SolverFactoryClass object ...>
+
+    or by importing the "special" name:
+
+    .. doctest::
+
+        >>> from pyomo.__future__ import solver_factory_v3
+
+    .. doctest::
+       :hide:
+
+       >>> from pyomo.__future__ import solver_factory_v1
+
+    """
+    import pyomo.opt.base.solvers as _solvers
+    import pyomo.contrib.solver.factory as _contrib
+    import pyomo.contrib.appsi.base as _appsi
+
+    versions = {
+        1: _solvers.LegacySolverFactory,
+        2: _appsi.SolverFactory,
+        3: _contrib.SolverFactory,
+    }
+
+    current = getattr(solver_factory, '_active_version', None)
+    # First time through, _active_version is not defined.  Go look and
+    # see what it was initialized to in pyomo.environ
+    if current is None:
+        for ver, cls in versions.items():
+            if cls._cls is _environ.SolverFactory._cls:
+                solver_factory._active_version = ver
+                break
+        return solver_factory._active_version
+    #
+    # The user is just asking what the current SolverFactory is; tell them.
+    if version is None:
+        return solver_factory._active_version
+    #
+    # Update the current SolverFactory to be a shim around (shallow copy
+    # of) the new active factory
+    src = versions.get(version, None)
+    if version is not None:
+        solver_factory._active_version = version
+        for attr in ('_description', '_cls', '_doc'):
+            setattr(_environ.SolverFactory, attr, getattr(src, attr))
+    else:
+        raise ValueError(
+            "Invalid value for target solver factory version; expected {1, 2, 3}, "
+            f"received {version}"
+        )
+    return src
+
+
+solver_factory._active_version = solver_factory()
diff --git a/pyomo/__init__.py b/pyomo/__init__.py
index 20ee59d48b2..14cc42b626e 100644
--- a/pyomo/__init__.py
+++ b/pyomo/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/__init__.py b/pyomo/common/__init__.py
index 563974b5617..d7297c067c9 100644
--- a/pyomo/common/__init__.py
+++ b/pyomo/common/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/_command.py b/pyomo/common/_command.py
index ae633648ace..ad521659aa7 100644
--- a/pyomo/common/_command.py
+++ b/pyomo/common/_command.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -13,8 +13,6 @@
 Management of Pyomo commands
 """
 
-__all__ = ['pyomo_command', 'get_pyomo_commands']
-
 import logging
 
 logger = logging.getLogger('pyomo.common')
diff --git a/pyomo/common/_common.py b/pyomo/common/_common.py
index 21a5ddcc7bc..0d50f74537a 100644
--- a/pyomo/common/_common.py
+++ b/pyomo/common/_common.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/autoslots.py b/pyomo/common/autoslots.py
index 1b55a818b83..89fefaf4f21 100644
--- a/pyomo/common/autoslots.py
+++ b/pyomo/common/autoslots.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -29,7 +29,7 @@ def _deepcopy_tuple(obj, memo, _id):
             unchanged = False
     if unchanged:
         # Python does not duplicate "unchanged" tuples (i.e. allows the
-        # original objecct to be returned from deepcopy()).  We will
+        # original object to be returned from deepcopy()).  We will
         # preserve that behavior here.
         #
         # It also appears to be faster *not* to cache the fact that this
diff --git a/pyomo/common/backports.py b/pyomo/common/backports.py
index 36f2dac87ab..e70b0f6d267 100644
--- a/pyomo/common/backports.py
+++ b/pyomo/common/backports.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/cmake_builder.py b/pyomo/common/cmake_builder.py
index bb612b43b72..523dbf64c91 100644
--- a/pyomo/common/cmake_builder.py
+++ b/pyomo/common/cmake_builder.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/collections/__init__.py b/pyomo/common/collections/__init__.py
index 9ffd1e931f6..717caf87b2c 100644
--- a/pyomo/common/collections/__init__.py
+++ b/pyomo/common/collections/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -14,6 +14,6 @@
 from collections import UserDict
 
 from .orderedset import OrderedDict, OrderedSet
-from .component_map import ComponentMap
+from .component_map import ComponentMap, DefaultComponentMap
 from .component_set import ComponentSet
 from .bunch import Bunch
diff --git a/pyomo/common/collections/bunch.py b/pyomo/common/collections/bunch.py
index f19e4ad64e3..2ae9cf8c517 100644
--- a/pyomo/common/collections/bunch.py
+++ b/pyomo/common/collections/bunch.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/collections/component_map.py b/pyomo/common/collections/component_map.py
index 41796876d7c..8dcfdb6c837 100644
--- a/pyomo/common/collections/component_map.py
+++ b/pyomo/common/collections/component_map.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,21 +9,49 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-from collections.abc import MutableMapping as collections_MutableMapping
+import collections
 from collections.abc import Mapping as collections_Mapping
 from pyomo.common.autoslots import AutoSlots
 
 
-def _rebuild_ids(encode, val):
+def _rehash_keys(encode, val):
     if encode:
         return val
     else:
         # object id() may have changed after unpickling,
         # so we rebuild the dictionary keys
-        return {id(obj): (obj, v) for obj, v in val.values()}
+        return {_hasher[obj.__class__](obj): (obj, v) for obj, v in val.values()}
 
 
-class ComponentMap(AutoSlots.Mixin, collections_MutableMapping):
+class _Hasher(collections.defaultdict):
+    def __init__(self, *args, **kwargs):
+        super().__init__(lambda: self._missing_impl, *args, **kwargs)
+        self[tuple] = self._tuple
+
+    def _missing_impl(self, val):
+        try:
+            hash(val)
+            self[val.__class__] = self._hashable
+        except:
+            self[val.__class__] = self._unhashable
+        return self[val.__class__](val)
+
+    @staticmethod
+    def _hashable(val):
+        return val
+
+    @staticmethod
+    def _unhashable(val):
+        return id(val)
+
+    def _tuple(self, val):
+        return tuple(self[i.__class__](i) for i in val)
+
+
+_hasher = _Hasher()
+
+
+class ComponentMap(AutoSlots.Mixin, collections.abc.MutableMapping):
     """
     This class is a replacement for dict that allows Pyomo
     modeling components to be used as entry keys. The
@@ -49,18 +77,18 @@ class ComponentMap(AutoSlots.Mixin, collections_MutableMapping):
     """
 
     __slots__ = ("_dict",)
-    __autoslot_mappers__ = {'_dict': _rebuild_ids}
+    __autoslot_mappers__ = {'_dict': _rehash_keys}
 
     def __init__(self, *args, **kwds):
-        # maps id(obj) -> (obj,val)
+        # maps id_hash(obj) -> (obj,val)
         self._dict = {}
         # handle the dict-style initialization scenarios
         self.update(*args, **kwds)
 
     def __str__(self):
         """String representation of the mapping."""
-        tmp = {str(c) + " (id=" + str(id(c)) + ")": v for c, v in self.items()}
-        return "ComponentMap(" + str(tmp) + ")"
+        tmp = {f"{v[0]} (key={k})": v[1] for k, v in self._dict.items()}
+        return f"ComponentMap({tmp})"
 
     #
     # Implement MutableMapping abstract methods
@@ -68,18 +96,20 @@ def __str__(self):
 
     def __getitem__(self, obj):
         try:
-            return self._dict[id(obj)][1]
+            return self._dict[_hasher[obj.__class__](obj)][1]
         except KeyError:
-            raise KeyError("Component with id '%s': %s" % (id(obj), str(obj)))
+            _id = _hasher[obj.__class__](obj)
+            raise KeyError(f"{obj} (key={_id})") from None
 
     def __setitem__(self, obj, val):
-        self._dict[id(obj)] = (obj, val)
+        self._dict[_hasher[obj.__class__](obj)] = (obj, val)
 
     def __delitem__(self, obj):
         try:
-            del self._dict[id(obj)]
+            del self._dict[_hasher[obj.__class__](obj)]
         except KeyError:
-            raise KeyError("Component with id '%s': %s" % (id(obj), str(obj)))
+            _id = _hasher[obj.__class__](obj)
+            raise KeyError(f"{obj} (key={_id})") from None
 
     def __iter__(self):
         return (obj for obj, val in self._dict.values())
@@ -107,7 +137,7 @@ def __eq__(self, other):
             return False
         # Note we have already verified the dicts are the same size
         for key, val in other.items():
-            other_id = id(key)
+            other_id = _hasher[key.__class__](key)
             if other_id not in self._dict:
                 return False
             self_val = self._dict[other_id][1]
@@ -130,7 +160,7 @@ def __ne__(self, other):
     #
 
     def __contains__(self, obj):
-        return id(obj) in self._dict
+        return _hasher[obj.__class__](obj) in self._dict
 
     def clear(self):
         'D.clear() -> None.  Remove all items from D.'
@@ -149,3 +179,32 @@ def setdefault(self, key, default=None):
         else:
             self[key] = default
         return default
+
+
+class DefaultComponentMap(ComponentMap):
+    """A :py:class:`defaultdict` admitting Pyomo Components as keys
+
+    This class is a replacement for defaultdict that allows Pyomo
+    modeling components to be used as entry keys. The base
+    implementation builds on :py:class:`ComponentMap`.
+
+    """
+
+    __slots__ = ('default_factory',)
+
+    def __init__(self, default_factory=None, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.default_factory = default_factory
+
+    def __missing__(self, key):
+        if self.default_factory is None:
+            raise KeyError(key)
+        self[key] = ans = self.default_factory()
+        return ans
+
+    def __getitem__(self, obj):
+        _key = _hasher[obj.__class__](obj)
+        if _key in self._dict:
+            return self._dict[_key][1]
+        else:
+            return self.__missing__(obj)
diff --git a/pyomo/common/collections/component_set.py b/pyomo/common/collections/component_set.py
index e205773220f..6e12bad7277 100644
--- a/pyomo/common/collections/component_set.py
+++ b/pyomo/common/collections/component_set.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -12,8 +12,30 @@
 from collections.abc import MutableSet as collections_MutableSet
 from collections.abc import Set as collections_Set
 
+from pyomo.common.autoslots import AutoSlots
+from pyomo.common.collections.component_map import _hasher
+
+
+def _rehash_keys(encode, val):
+    if encode:
+        # TBD [JDS 2/2024]: if we
+        #
+        # return list(val.values())
+        #
+        # here, then we get a strange failure when deepcopying
+        # ComponentSets containing an _ImplicitAny domain.  We could
+        # track it down to the implementation of
+        # autoslots.fast_deepcopy, but couldn't find an obvious bug.
+        # There is no error if we just return the original dict, or if
+        # we return a tuple(val.values)
+        return val
+    else:
+        # object id() may have changed after unpickling,
+        # so we rebuild the dictionary keys
+        return {_hasher[obj.__class__](obj): obj for obj in val.values()}
+
 
-class ComponentSet(collections_MutableSet):
+class ComponentSet(AutoSlots.Mixin, collections_MutableSet):
     """
     This class is a replacement for set that allows Pyomo
     modeling components to be used as entries. The
@@ -38,47 +60,32 @@ class ComponentSet(collections_MutableSet):
     """
 
     __slots__ = ("_data",)
+    __autoslot_mappers__ = {'_data': _rehash_keys}
 
-    def __init__(self, *args):
-        self._data = dict()
-        if len(args) > 0:
-            if len(args) > 1:
-                raise TypeError(
-                    "%s expected at most 1 arguments, "
-                    "got %s" % (self.__class__.__name__, len(args))
-                )
-            self.update(args[0])
+    def __init__(self, iterable=None):
+        # maps id_hash(obj) -> obj
+        self._data = {}
+        if iterable is not None:
+            self.update(iterable)
 
     def __str__(self):
         """String representation of the mapping."""
-        tmp = []
-        for objid, obj in self._data.items():
-            tmp.append(str(obj) + " (id=" + str(objid) + ")")
-        return "ComponentSet(" + str(tmp) + ")"
+        tmp = [f"{v} (key={k})" for k, v in self._data.items()]
+        return f"ComponentSet({tmp})"
 
-    def update(self, args):
+    def update(self, iterable):
         """Update a set with the union of itself and others."""
-        self._data.update((id(obj), obj) for obj in args)
-
-    #
-    # This method must be defined for deepcopy/pickling
-    # because this class relies on Python ids.
-    #
-    def __setstate__(self, state):
-        # object id() may have changed after unpickling,
-        # so we rebuild the dictionary keys
-        assert len(state) == 1
-        self._data = {id(obj): obj for obj in state['_data']}
-
-    def __getstate__(self):
-        return {'_data': tuple(self._data.values())}
+        if isinstance(iterable, ComponentSet):
+            self._data.update(iterable._data)
+        else:
+            self._data.update((_hasher[val.__class__](val), val) for val in iterable)
 
     #
     # Implement MutableSet abstract methods
     #
 
     def __contains__(self, val):
-        return self._data.__contains__(id(val))
+        return _hasher[val.__class__](val) in self._data
 
     def __iter__(self):
         return iter(self._data.values())
@@ -88,27 +95,26 @@ def __len__(self):
 
     def add(self, val):
         """Add an element."""
-        self._data[id(val)] = val
+        self._data[_hasher[val.__class__](val)] = val
 
     def discard(self, val):
         """Remove an element. Do not raise an exception if absent."""
-        if id(val) in self._data:
-            del self._data[id(val)]
+        _id = _hasher[val.__class__](val)
+        if _id in self._data:
+            del self._data[_id]
 
     #
     # Overload MutableSet default implementations
     #
 
-    # We want to avoid generating Pyomo expressions due to
-    # comparison of values, so we convert both objects to a
-    # plain dictionary mapping key->(type(val), id(val)) and
-    # compare that instead.
     def __eq__(self, other):
         if self is other:
             return True
         if not isinstance(other, collections_Set):
             return False
-        return len(self) == len(other) and all(id(key) in self._data for key in other)
+        return len(self) == len(other) and all(
+            _hasher[val.__class__](val) in self._data for val in other
+        )
 
     def __ne__(self, other):
         return not (self == other)
@@ -125,6 +131,7 @@ def clear(self):
     def remove(self, val):
         """Remove an element. If not a member, raise a KeyError."""
         try:
-            del self._data[id(val)]
+            del self._data[_hasher[val.__class__](val)]
         except KeyError:
-            raise KeyError("Component with id '%s': %s" % (id(val), str(val)))
+            _id = _hasher[val.__class__](val)
+            raise KeyError(f"{val} (key={_id})") from None
diff --git a/pyomo/common/collections/orderedset.py b/pyomo/common/collections/orderedset.py
index 448939c8822..834101e3896 100644
--- a/pyomo/common/collections/orderedset.py
+++ b/pyomo/common/collections/orderedset.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,42 +9,30 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-from collections.abc import MutableSet
 from collections import OrderedDict
+from collections.abc import MutableSet
+from pyomo.common.autoslots import AutoSlots
 
 
-class OrderedSet(MutableSet):
+class OrderedSet(AutoSlots.Mixin, MutableSet):
     __slots__ = ('_dict',)
 
     def __init__(self, iterable=None):
-        # TODO: Starting in Python 3.7, dict is ordered (and is faster
-        # than OrderedDict).  dict began supporting reversed() in 3.8.
-        # We should consider changing the underlying data type here from
-        # OrderedDict to dict.
-        self._dict = OrderedDict()
+        # Starting in Python 3.7, dict is ordered (and is faster than
+        # OrderedDict).  dict began supporting reversed() in 3.8.
+        self._dict = {}
         if iterable is not None:
-            if iterable.__class__ is OrderedSet:
-                self._dict.update(iterable._dict)
-            else:
-                self.update(iterable)
+            self.update(iterable)
 
     def __str__(self):
         """String representation of the mapping."""
         return "OrderedSet(%s)" % (', '.join(repr(x) for x in self))
 
     def update(self, iterable):
-        for val in iterable:
-            self.add(val)
-
-    #
-    # This method must be defined for deepcopy/pickling
-    # because this class is slotized.
-    #
-    def __setstate__(self, state):
-        self._dict = state
-
-    def __getstate__(self):
-        return self._dict
+        if isinstance(iterable, OrderedSet):
+            self._dict.update(iterable._dict)
+        else:
+            self._dict.update((val, None) for val in iterable)
 
     #
     # Implement MutableSet abstract methods
diff --git a/pyomo/common/config.py b/pyomo/common/config.py
index 15f15872fc6..ebba2f2732a 100644
--- a/pyomo/common/config.py
+++ b/pyomo/common/config.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -39,7 +39,6 @@
     deprecation_warning,
     relocated_module_attribute,
 )
-from pyomo.common.errors import DeveloperError
 from pyomo.common.fileutils import import_file
 from pyomo.common.formatting import wrap_reStructuredText
 from pyomo.common.modeling import NOTSET
@@ -302,6 +301,70 @@ def domain_name(self):
         return f'InEnum[{self._domain.__name__}]'
 
 
+class IsInstance(object):
+    """
+    Domain validator for type checking.
+
+    Parameters
+    ----------
+    *bases : tuple of type
+        Valid types.
+    document_full_base_names : bool, optional
+        True to prepend full module qualifier to the name of each
+        member of `bases` in ``self.domain_name()`` and/or any
+        error messages generated by this object, False otherwise.
+    """
+
+    def __init__(self, *bases, document_full_base_names=False):
+        assert bases
+        self.baseClasses = bases
+        self.document_full_base_names = document_full_base_names
+
+    @staticmethod
+    def _fullname(klass):
+        """
+        Get full name of class, including appropriate module qualifier.
+        """
+        module_name = klass.__module__
+        module_qual = "" if module_name == "builtins" else f"{module_name}."
+        return f"{module_qual}{klass.__name__}"
+
+    def _get_class_name(self, klass):
+        """
+        Get name of class. Module qualifier may be included,
+        depending on value of `self.document_full_base_names`.
+        """
+        if self.document_full_base_names:
+            return self._fullname(klass)
+        else:
+            return klass.__name__
+
+    def __call__(self, obj):
+        if isinstance(obj, self.baseClasses):
+            return obj
+        if len(self.baseClasses) > 1:
+            class_names = ", ".join(
+                f"{self._get_class_name(kls)!r}" for kls in self.baseClasses
+            )
+            msg = (
+                "Expected an instance of one of these types: "
+                f"{class_names}, but received value {obj!r} of type "
+                f"{self._get_class_name(type(obj))!r}"
+            )
+        else:
+            msg = (
+                f"Expected an instance of "
+                f"{self._get_class_name(self.baseClasses[0])!r}, "
+                f"but received value {obj!r} of type "
+                f"{self._get_class_name(type(obj))!r}"
+            )
+        raise ValueError(msg)
+
+    def domain_name(self):
+        class_names = (self._get_class_name(kls) for kls in self.baseClasses)
+        return f"IsInstance({', '.join(class_names)})"
+
+
 class ListOf(object):
     """Domain validator for lists of a specified type
 
@@ -424,9 +487,14 @@ def __call__(self, module_id):
 
 
 class Path(object):
-    """Domain validator for path-like options.
+    """
+    Domain validator for a
+    :py:term:`path-like object <path-like object>`.
 
-    This will admit any object and convert it to a string.  It will then
+    This will admit a path-like object
+    and get the object's file system representation
+    through :py:obj:`os.fsdecode`.
+    It will then
     expand any environment variables and leading usernames (e.g.,
     "~myuser" or "~/") appearing in either the value or the base path
     before concatenating the base path and value, expanding the path to
@@ -454,7 +522,7 @@ def __init__(self, basePath=None, expandPath=None):
         self.expandPath = expandPath
 
     def __call__(self, path):
-        path = str(path)
+        path = os.fsdecode(path)
         _expand = self.expandPath
         if _expand is None:
             _expand = not Path.SuppressPathExpansion
@@ -489,14 +557,21 @@ def __call__(self, path):
         )
         return ans
 
+    def domain_name(self):
+        return type(self).__name__
+
 
 class PathList(Path):
-    """Domain validator for a list of path-like objects.
+    """
+    Domain validator for a list of
+    :py:term:`path-like objects <path-like object>`.
 
-    This will admit any iterable or object convertible to a string.
-    Iterable objects (other than strings) will have each member
-    normalized using :py:class:`Path`.  Other types will be passed to
-    :py:class:`Path`, returning a list with the single resulting path.
+    This admits a path-like object or iterable of such.
+    If a path-like object is passed, then
+    a singleton list containing the object normalized through
+    :py:class:`Path` is returned.
+    An iterable of path-like objects is cast to a list, each
+    entry of which is normalized through :py:class:`Path`.
 
     Parameters
     ----------
@@ -513,7 +588,8 @@ class PathList(Path):
     """
 
     def __call__(self, data):
-        if hasattr(data, "__iter__") and not isinstance(data, str):
+        is_path_like = isinstance(data, (str, bytes)) or hasattr(data, "__fspath__")
+        if hasattr(data, "__iter__") and not is_path_like:
             return [super(PathList, self).__call__(i) for i in data]
         else:
             return [super(PathList, self).__call__(data)]
@@ -709,6 +785,7 @@ def from_enum_or_string(cls, arg):
    NonNegativeFloat
    In
    InEnum
+   IsInstance
    ListOf
    Module
    Path
@@ -919,7 +996,7 @@ class will still create ``c`` instances that only have the single
 :py:meth:`generate_documentation()`.  The simplest is
 :py:meth:`display()`, which prints out the current values of the
 configuration object (and if it is a container type, all of it's
-children).  :py:meth:`generate_yaml_template` is simular to
+children).  :py:meth:`generate_yaml_template` is similar to
 :py:meth:`display`, but also includes the description fields as
 formatted comments.
 
@@ -1028,8 +1105,11 @@ class will still create ``c`` instances that only have the single
 
 
 def _dump(*args, **kwds):
+    # TODO: Change the default behavior to no longer be YAML.
+    # This was a legacy decision that may no longer be the best
+    # decision, given changes to technology over the years.
     try:
-        from yaml import dump
+        from yaml import safe_dump as dump
     except ImportError:
         # dump = lambda x,**y: str(x)
         # YAML uses lowercase True/False
@@ -1054,7 +1134,11 @@ def _domain_name(domain):
     if domain is None:
         return ""
     elif hasattr(domain, 'domain_name'):
-        return domain.domain_name()
+        dn = domain.domain_name
+        if hasattr(dn, '__call__'):
+            return dn()
+        else:
+            return dn
     elif domain.__class__ is type:
         return domain.__name__
     elif inspect.isfunction(domain):
@@ -1090,7 +1174,9 @@ def _value2string(prefix, value, obj):
         try:
             _data = value._data if value is obj else value
             if getattr(builtins, _data.__class__.__name__, None) is not None:
-                _str += _dump(_data, default_flow_style=True).rstrip()
+                _str += _dump(
+                    _data, default_flow_style=True, allow_unicode=True
+                ).rstrip()
                 if _str.endswith("..."):
                     _str = _str[:-3].rstrip()
             else:
diff --git a/pyomo/common/dependencies.py b/pyomo/common/dependencies.py
index 0a179b5c2de..bbcea0b85d7 100644
--- a/pyomo/common/dependencies.py
+++ b/pyomo/common/dependencies.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,13 +9,16 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-from collections.abc import Mapping
 import inspect
 import importlib
 import logging
 import sys
 import warnings
 
+from collections.abc import Mapping
+from types import ModuleType
+from typing import List
+
 from .deprecation import deprecated, deprecation_warning, in_testing_environment
 from .errors import DeferredImportError
 
@@ -127,7 +130,7 @@ class DeferredImportModule(object):
 
     This object is returned by :py:func:`attempt_import()` in lieu of
     the module when :py:func:`attempt_import()` is called with
-    ``defer_check=True``.  Any attempts to access attributes on this
+    ``defer_import=True``.  Any attempts to access attributes on this
     object will trigger the actual module import and return either the
     appropriate module attribute or else if the module import fails,
     raise a :py:class:`.DeferredImportError` exception.
@@ -312,6 +315,12 @@ def __init__(
         self._module = None
         self._available = None
         self._deferred_submodules = deferred_submodules
+        # If this import has a callback, then record this deferred
+        # import so that any direct imports of this module also trigger
+        # the resolution of this DeferredImportIndicator (and the
+        # corresponding callback)
+        if callback is not None:
+            DeferredImportCallbackFinder._callbacks.setdefault(name, []).append(self)
 
     def __bool__(self):
         self.resolve()
@@ -433,6 +442,83 @@ def check_min_version(module, min_version):
 check_min_version._parser = None
 
 
+#
+# Note that we are duck-typing the Loader and MetaPathFinder base
+# classes from importlib.abc.  This avoids a (surprisingly costly)
+# import of importlib.abc
+#
+class DeferredImportCallbackLoader:
+    """Custom Loader to resolve registered :py:class:`DeferredImportIndicator` objects
+
+    This :py:class:`importlib.abc.Loader` loader wraps a regular loader
+    and automatically resolves the registered
+    :py:class:`DeferredImportIndicator` objects after the module is
+    loaded.
+
+    """
+
+    def __init__(self, loader, deferred_indicators: List[DeferredImportIndicator]):
+        self._loader = loader
+        self._deferred_indicators = deferred_indicators
+
+    def module_repr(self, module: ModuleType) -> str:
+        return self._loader.module_repr(module)
+
+    def create_module(self, spec) -> ModuleType:
+        return self._loader.create_module(spec)
+
+    def exec_module(self, module: ModuleType) -> None:
+        self._loader.exec_module(module)
+        # Now that the module has been loaded, trigger the resolution of
+        # the deferred indicators (and their associated callbacks)
+        for deferred in self._deferred_indicators:
+            deferred.resolve()
+
+    def load_module(self, fullname) -> ModuleType:
+        return self._loader.load_module(fullname)
+
+
+class DeferredImportCallbackFinder:
+    """Custom Finder that will wrap the normal loader to trigger callbacks
+
+    This :py:class:`importlib.abc.MetaPathFinder` finder will wrap the
+    normal loader returned by ``PathFinder`` with a loader that will
+    trigger custom callbacks after the module is loaded.  We use this to
+    trigger the post import callbacks registered through
+    :py:func:`attempt_import` even when a user imports the target library
+    directly (and not through attribute access on the
+    :py:class:`DeferredImportModule`.
+
+    """
+
+    _callbacks = {}
+
+    def find_spec(self, fullname, path, target=None):
+        if fullname not in self._callbacks:
+            return None
+
+        spec = importlib.machinery.PathFinder.find_spec(fullname, path, target)
+        if spec is None:
+            # Module not found.  Returning None will proceed to the next
+            # finder (which is likely to raise a ModuleNotFoundError)
+            return None
+        spec.loader = DeferredImportCallbackLoader(
+            spec.loader, self._callbacks[fullname]
+        )
+        return spec
+
+    def invalidate_caches(self):
+        pass
+
+
+_DeferredImportCallbackFinder = DeferredImportCallbackFinder()
+# Insert the DeferredImportCallbackFinder at the beginning of the
+# sys.meta_path so that it is found before the standard finders (so that
+# we can correctly inject the resolution of the DeferredImportIndicators
+# -- which triggers the needed callbacks)
+sys.meta_path.insert(0, _DeferredImportCallbackFinder)
+
+
 def attempt_import(
     name,
     error_message=None,
@@ -441,7 +527,8 @@ def attempt_import(
     alt_names=None,
     callback=None,
     importer=None,
-    defer_check=True,
+    defer_check=None,
+    defer_import=None,
     deferred_submodules=None,
     catch_exceptions=None,
 ):
@@ -495,7 +582,8 @@ def attempt_import(
         The message for the exception raised by :py:class:`ModuleUnavailable`
 
     only_catch_importerror: bool, optional
-        DEPRECATED: use catch_exceptions instead or only_catch_importerror.
+        DEPRECATED: use ``catch_exceptions`` instead of ``only_catch_importerror``.
+
         If True (the default), exceptions other than ``ImportError`` raised
         during module import will be reraised.  If False, any exception
         will result in returning a :py:class:`ModuleUnavailable` object.
@@ -506,13 +594,14 @@ def attempt_import(
         ``module.__version__``)
 
     alt_names: list, optional
-        DEPRECATED: alt_names no longer needs to be specified and is ignored.
+        DEPRECATED: ``alt_names`` no longer needs to be specified and is ignored.
+
         A list of common alternate names by which to look for this
         module in the ``globals()`` namespaces.  For example, the alt_names
         for NumPy would be ``['np']``.  (deprecated in version 6.0)
 
-    callback: function, optional
-        A function with the signature "``fcn(module, available)``" that
+    callback: Callable[[ModuleType, bool], None], optional
+        A function with the signature ``fcn(module, available)`` that
         will be called after the import is first attempted.
 
     importer: function, optional
@@ -522,10 +611,16 @@ def attempt_import(
         want to import/return the first one that is available.
 
     defer_check: bool, optional
-        If True (the default), then the attempted import is deferred
-        until the first use of either the module or the availability
-        flag.  The method will return instances of :py:class:`DeferredImportModule`
-        and :py:class:`DeferredImportIndicator`.
+        DEPRECATED: renamed to ``defer_import`` (deprecated in version 6.7.2)
+
+    defer_import: bool, optional
+        If True, then the attempted import is deferred until the first
+        use of either the module or the availability flag.  The method
+        will return instances of :py:class:`DeferredImportModule` and
+        :py:class:`DeferredImportIndicator`.  If False, the import will
+        be attempted immediately.  If not set, then the import will be
+        deferred unless the ``name`` is already present in
+        ``sys.modules``.
 
     deferred_submodules: Iterable[str], optional
         If provided, an iterable of submodule names within this module
@@ -576,9 +671,26 @@ def attempt_import(
     if catch_exceptions is None:
         catch_exceptions = (ImportError,)
 
+    if defer_check is not None:
+        deprecation_warning(
+            'defer_check=%s is deprecated.  Please use defer_import' % (defer_check,),
+            version='6.7.2',
+        )
+        assert defer_import is None
+        defer_import = defer_check
+
+    # If the module has already been imported, there is no reason to
+    # further defer things: just import it.
+    if defer_import is None:
+        if name in sys.modules:
+            defer_import = False
+            deferred_submodules = None
+        else:
+            defer_import = True
+
     # If we are going to defer the check until later, return the
     # deferred import module object
-    if defer_check:
+    if defer_import:
         if deferred_submodules:
             if isinstance(deferred_submodules, Mapping):
                 deprecation_warning(
@@ -621,7 +733,7 @@ def attempt_import(
         return DeferredImportModule(indicator, deferred, None), indicator
 
     if deferred_submodules:
-        raise ValueError("deferred_submodules is only valid if defer_check==True")
+        raise ValueError("deferred_submodules is only valid if defer_import==True")
 
     return _perform_import(
         name=name,
@@ -672,6 +784,11 @@ def _perform_import(
     return module, False
 
 
+@deprecated(
+    "``declare_deferred_modules_as_importable()`` is deprecated.  "
+    "Use the :py:class:`declare_modules_as_importable` context manager.",
+    version='6.7.2',
+)
 def declare_deferred_modules_as_importable(globals_dict):
     """Make all :py:class:`DeferredImportModules` in ``globals_dict`` importable
 
@@ -698,6 +815,7 @@ def declare_deferred_modules_as_importable(globals_dict):
        ...     'scipy', callback=_finalize_scipy,
        ...     deferred_submodules=['stats', 'sparse', 'spatial', 'integrate'])
        >>> declare_deferred_modules_as_importable(globals())
+       WARNING: DEPRECATED: ...
 
     Which enables users to use:
 
@@ -712,20 +830,87 @@ def declare_deferred_modules_as_importable(globals_dict):
     :py:class:`ModuleUnavailable` instance.
 
     """
-    _global_name = globals_dict['__name__'] + '.'
-    deferred = list(
-        (k, v) for k, v in globals_dict.items() if type(v) is DeferredImportModule
-    )
-    while deferred:
-        name, mod = deferred.pop(0)
-        mod.__path__ = None
-        mod.__spec__ = None
-        sys.modules[_global_name + name] = mod
-        deferred.extend(
-            (name + '.' + k, v)
-            for k, v in mod.__dict__.items()
-            if type(v) is DeferredImportModule
-        )
+    return declare_modules_as_importable(globals_dict).__exit__(None, None, None)
+
+
+class declare_modules_as_importable(object):
+    """Make all :py:class:`ModuleType` and :py:class:`DeferredImportModules`
+    importable through the ``globals_dict`` context.
+
+    This context manager will detect all modules imported into the
+    specified ``globals_dict`` environment (either directly or through
+    :py:func:`attempt_import`) and will make those modules importable
+    from the specified ``globals_dict`` context.  It works by detecting
+    changes in the specified ``globals_dict`` dictionary and adding any new
+    modules or instances of :py:class:`DeferredImportModule` that it
+    finds (and any of their deferred submodules) to ``sys.modules`` so
+    that the modules can be imported through the ``globals_dict``
+    namespace.
+
+    For example, ``pyomo/common/dependencies.py`` declares:
+
+    .. doctest::
+       :hide:
+
+       >>> from pyomo.common.dependencies import (
+       ...     attempt_import, _finalize_scipy, __dict__ as dep_globals,
+       ...     declare_modules_as_importable, )
+       >>> # Sphinx does not provide a proper globals()
+       >>> def globals(): return dep_globals
+
+    .. doctest::
+
+       >>> with declare_modules_as_importable(globals()):
+       ...     scipy, scipy_available = attempt_import(
+       ...        'scipy', callback=_finalize_scipy,
+       ...        deferred_submodules=['stats', 'sparse', 'spatial', 'integrate'])
+
+    Which enables users to use:
+
+    .. doctest::
+
+       >>> import pyomo.common.dependencies.scipy.sparse as spa
+
+    If the deferred import has not yet been triggered, then the
+    :py:class:`DeferredImportModule` is returned and named ``spa``.
+    However, if the import has already been triggered, then ``spa`` will
+    either be the ``scipy.sparse`` module, or a
+    :py:class:`ModuleUnavailable` instance.
+
+    """
+
+    def __init__(self, globals_dict):
+        self.globals_dict = globals_dict
+        self.init_dict = {}
+        self.init_modules = None
+
+    def __enter__(self):
+        self.init_dict.update(self.globals_dict)
+        self.init_modules = set(sys.modules)
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        _global_name = self.globals_dict['__name__'] + '.'
+        deferred = {
+            k: v
+            for k, v in self.globals_dict.items()
+            if k not in self.init_dict
+            and isinstance(v, (ModuleType, DeferredImportModule))
+        }
+        if self.init_modules:
+            for name in set(sys.modules) - self.init_modules:
+                if '.' in name and name.split('.', 1)[0] in deferred:
+                    sys.modules[_global_name + name] = sys.modules[name]
+        while deferred:
+            name, mod = deferred.popitem()
+            sys.modules[_global_name + name] = mod
+            if isinstance(mod, DeferredImportModule):
+                mod.__path__ = None
+                mod.__spec__ = None
+                deferred.update(
+                    (name + '.' + k, v)
+                    for k, v in mod.__dict__.items()
+                    if type(v) is DeferredImportModule
+                )
 
 
 #
@@ -778,11 +963,18 @@ def _finalize_matplotlib(module, available):
     if in_testing_environment():
         module.use('Agg')
     import matplotlib.pyplot
+    import matplotlib.pylab
+    import matplotlib.backends
 
 
 def _finalize_numpy(np, available):
     if not available:
         return
+    # scipy has a dependence on numpy.testing, and if we don't import it
+    # as part of resolving numpy, then certain deferred scipy imports
+    # fail when run under pytest.
+    import numpy.testing
+
     from . import numeric_types
 
     # Register ndarray as a native type to prevent 1-element ndarrays
@@ -807,10 +999,13 @@ def _finalize_numpy(np, available):
         # registration here (to bypass the deprecation warning) until we
         # finally remove all support for it
         numeric_types._native_boolean_types.add(t)
-    _floats = [np.float_, np.float16, np.float32, np.float64]
+    _floats = [np.float16, np.float32, np.float64]
     # float96 and float128 may or may not be defined in this particular
     # numpy build (it depends on platform and version).
     # Register them only if they are present
+    if hasattr(np, 'float_'):
+        # Prepend to preserve previous functionality
+        _floats.insert(0, np.float_)
     if hasattr(np, 'float96'):
         _floats.append(np.float96)
     if hasattr(np, 'float128'):
@@ -821,10 +1016,13 @@ def _finalize_numpy(np, available):
         # registration here (to bypass the deprecation warning) until we
         # finally remove all support for it
         numeric_types._native_boolean_types.add(t)
-    _complex = [np.complex_, np.complex64, np.complex128]
+    _complex = [np.complex64, np.complex128]
     # complex192 and complex256 may or may not be defined in this
     # particular numpy build (it depends on platform and version).
     # Register them only if they are present
+    if hasattr(np, 'np.complex_'):
+        # Prepend to preserve functionality
+        _complex.insert(0, np.complex_)
     if hasattr(np, 'complex192'):
         _complex.append(np.complex192)
     if hasattr(np, 'complex256'):
@@ -842,41 +1040,42 @@ def _pyutilib_importer():
     return importlib.import_module('pyutilib')
 
 
-# Standard libraries that are slower to import and not strictly required
-# on all platforms / situations.
-ctypes, _ = attempt_import(
-    'ctypes', deferred_submodules=['util'], callback=_finalize_ctypes
-)
-random, _ = attempt_import('random')
-
-# Commonly-used optional dependencies
-dill, dill_available = attempt_import('dill')
-mpi4py, mpi4py_available = attempt_import('mpi4py')
-networkx, networkx_available = attempt_import('networkx')
-numpy, numpy_available = attempt_import('numpy', callback=_finalize_numpy)
-pandas, pandas_available = attempt_import('pandas')
-plotly, plotly_available = attempt_import('plotly')
-pympler, pympler_available = attempt_import('pympler', callback=_finalize_pympler)
-pyutilib, pyutilib_available = attempt_import('pyutilib', importer=_pyutilib_importer)
-scipy, scipy_available = attempt_import(
-    'scipy',
-    callback=_finalize_scipy,
-    deferred_submodules=['stats', 'sparse', 'spatial', 'integrate'],
-)
-yaml, yaml_available = attempt_import('yaml', callback=_finalize_yaml)
-
-# Note that matplotlib.pyplot can generate a runtime error on OSX when
-# not installed as a Framework (as is the case in the CI systems)
-matplotlib, matplotlib_available = attempt_import(
-    'matplotlib',
-    callback=_finalize_matplotlib,
-    deferred_submodules=['pyplot', 'pylab'],
-    catch_exceptions=(ImportError, RuntimeError),
-)
+with declare_modules_as_importable(globals()):
+    # Standard libraries that are slower to import and not strictly required
+    # on all platforms / situations.
+    ctypes, _ = attempt_import(
+        'ctypes', deferred_submodules=['util'], callback=_finalize_ctypes
+    )
+    random, _ = attempt_import('random')
+
+    # Commonly-used optional dependencies
+    dill, dill_available = attempt_import('dill')
+    mpi4py, mpi4py_available = attempt_import('mpi4py')
+    networkx, networkx_available = attempt_import('networkx')
+    numpy, numpy_available = attempt_import('numpy', callback=_finalize_numpy)
+    pandas, pandas_available = attempt_import('pandas')
+    plotly, plotly_available = attempt_import('plotly')
+    pympler, pympler_available = attempt_import('pympler', callback=_finalize_pympler)
+    pyutilib, pyutilib_available = attempt_import(
+        'pyutilib', importer=_pyutilib_importer
+    )
+    scipy, scipy_available = attempt_import(
+        'scipy',
+        callback=_finalize_scipy,
+        deferred_submodules=['stats', 'sparse', 'spatial', 'integrate'],
+    )
+    yaml, yaml_available = attempt_import('yaml', callback=_finalize_yaml)
+
+    # Note that matplotlib.pyplot can generate a runtime error on OSX when
+    # not installed as a Framework (as is the case in the CI systems)
+    matplotlib, matplotlib_available = attempt_import(
+        'matplotlib',
+        callback=_finalize_matplotlib,
+        deferred_submodules=['pyplot', 'pylab', 'backends'],
+        catch_exceptions=(ImportError, RuntimeError),
+    )
 
 try:
     import cPickle as pickle
 except ImportError:
     import pickle
-
-declare_deferred_modules_as_importable(globals())
diff --git a/pyomo/common/deprecation.py b/pyomo/common/deprecation.py
index 2e39083770d..c674dcddc78 100644
--- a/pyomo/common/deprecation.py
+++ b/pyomo/common/deprecation.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -542,7 +542,7 @@ def __renamed__warning__(msg):
 
         if new_class is None and '__renamed__new_class__' not in classdict:
             if not any(
-                hasattr(base, '__renamed__new_class__')
+                hasattr(mro, '__renamed__new_class__')
                 for mro in itertools.chain.from_iterable(
                     base.__mro__ for base in renamed_bases
                 )
diff --git a/pyomo/common/download.py b/pyomo/common/download.py
index 79d5302a58e..ad3b64060e9 100644
--- a/pyomo/common/download.py
+++ b/pyomo/common/download.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -29,6 +29,7 @@
 urllib_error = attempt_import('urllib.error')[0]
 ssl = attempt_import('ssl')[0]
 zipfile = attempt_import('zipfile')[0]
+tarfile = attempt_import('tarfile')[0]
 gzip = attempt_import('gzip')[0]
 distro, distro_available = attempt_import('distro')
 
@@ -371,7 +372,7 @@ def get_zip_archive(self, url, dirOffset=0):
         # Simple sanity checks
         for info in zip_file.infolist():
             f = info.filename
-            if f[0] in '\\/' or '..' in f:
+            if f[0] in '\\/' or '..' in f or os.path.isabs(f):
                 logger.error(
                     "malformed (potentially insecure) filename (%s) "
                     "found in zip archive.  Skipping file." % (f,)
@@ -387,6 +388,61 @@ def get_zip_archive(self, url, dirOffset=0):
             info.filename = target[-1] + '/' if f[-1] == '/' else target[-1]
             zip_file.extract(f, os.path.join(self._fname, *tuple(target[dirOffset:-1])))
 
+    def get_tar_archive(self, url, dirOffset=0):
+        if self._fname is None:
+            raise DeveloperError(
+                "target file name has not been initialized "
+                "with set_destination_filename"
+            )
+        if os.path.exists(self._fname) and not os.path.isdir(self._fname):
+            raise RuntimeError(
+                "Target directory (%s) exists, but is not a directory" % (self._fname,)
+            )
+
+        def filter_fcn(info):
+            # this mocks up the `tarfile` filter introduced in Python
+            # 3.12 and backported to later releases of Python (e.g.,
+            # 3.8.17, 3.9.17, 3.10.12, and 3.11.4)
+            f = info.name
+            if os.path.isabs(f) or '..' in f or f.startswith(('/', os.sep)):
+                logger.error(
+                    "malformed or potentially insecure filename (%s).  "
+                    "Skipping file." % (f,)
+                )
+                return False
+            target = self._splitpath(f)
+            if len(target) <= dirOffset:
+                if not info.isdir():
+                    logger.warning(
+                        "Skipping file (%s) in tar archive due to dirOffset." % (f,)
+                    )
+                return False
+            info.name = f = '/'.join(target[dirOffset:])
+            target = os.path.realpath(os.path.join(dest, f))
+            try:
+                if os.path.commonpath([target, dest]) != dest:
+                    logger.error(
+                        "potentially insecure filename (%s) resolves outside target "
+                        "directory.  Skipping file." % (f,)
+                    )
+                    return False
+            except ValueError:
+                # commonpath() will raise ValueError for paths that
+                # don't have anything in common (notably, when files are
+                # on different drives on Windows)
+                logger.error(
+                    "potentially insecure filename (%s) resolves outside target "
+                    "directory.  Skipping file." % (f,)
+                )
+                return False
+            # Strip high bits & group/other write bits
+            info.mode &= 0o755
+            return True
+
+        with tarfile.open(fileobj=io.BytesIO(self.retrieve_url(url))) as TAR:
+            dest = os.path.realpath(self._fname)
+            TAR.extractall(dest, filter(filter_fcn, TAR.getmembers()))
+
     def get_gzipped_binary_file(self, url):
         if self._fname is None:
             raise DeveloperError(
diff --git a/pyomo/common/enums.py b/pyomo/common/enums.py
new file mode 100644
index 00000000000..121155d4ae8
--- /dev/null
+++ b/pyomo/common/enums.py
@@ -0,0 +1,170 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+"""This module provides standard :py:class:`enum.Enum` definitions used in
+Pyomo, along with additional utilities for working with custom Enums
+
+Utilities:
+
+.. autosummary::
+
+   ExtendedEnumType
+   NamedIntEnum
+
+Standard Enums:
+
+.. autosummary::
+
+   ObjectiveSense
+
+"""
+
+import enum
+import itertools
+import sys
+
+if sys.version_info[:2] < (3, 11):
+    _EnumType = enum.EnumMeta
+else:
+    _EnumType = enum.EnumType
+
+
+class ExtendedEnumType(_EnumType):
+    """Metaclass for creating an :py:class:`enum.Enum` that extends another Enum
+
+    In general, :py:class:`enum.Enum` classes are not extensible: that is,
+    they are frozen when defined and cannot be the base class of another
+    Enum.  This Metaclass provides a workaround for creating a new Enum
+    that extends an existing enum.  Members in the base Enum are all
+    present as members on the extended enum.
+
+    Example
+    -------
+
+    .. testcode::
+       :hide:
+
+       import enum
+       from pyomo.common.enums import ExtendedEnumType
+
+    .. testcode::
+
+       class ObjectiveSense(enum.IntEnum):
+           minimize = 1
+           maximize = -1
+
+       class ProblemSense(enum.IntEnum, metaclass=ExtendedEnumType):
+           __base_enum__ = ObjectiveSense
+
+           unknown = 0
+
+    .. doctest::
+
+       >>> list(ProblemSense)
+       [<ProblemSense.unknown: 0>, <ObjectiveSense.minimize: 1>, <ObjectiveSense.maximize: -1>]
+       >>> ProblemSense.unknown
+       <ProblemSense.unknown: 0>
+       >>> ProblemSense.maximize
+       <ObjectiveSense.maximize: -1>
+       >>> ProblemSense(0)
+       <ProblemSense.unknown: 0>
+       >>> ProblemSense(1)
+       <ObjectiveSense.minimize: 1>
+       >>> ProblemSense('unknown')
+       <ProblemSense.unknown: 0>
+       >>> ProblemSense('maximize')
+       <ObjectiveSense.maximize: -1>
+       >>> hasattr(ProblemSense, 'minimize')
+       True
+       >>> ProblemSense.minimize is ObjectiveSense.minimize
+       True
+       >>> ProblemSense.minimize in ProblemSense
+       True
+
+    """
+
+    def __getattr__(cls, attr):
+        try:
+            return getattr(cls.__base_enum__, attr)
+        except:
+            return super().__getattr__(attr)
+
+    def __iter__(cls):
+        # The members of this Enum are the base enum members joined with
+        # the local members
+        return itertools.chain(super().__iter__(), cls.__base_enum__.__iter__())
+
+    def __contains__(cls, member):
+        # This enum "contains" both its local members and the members in
+        # the __base_enum__ (necessary for good auto-enum[sphinx] docs)
+        return super().__contains__(member) or member in cls.__base_enum__
+
+    def __instancecheck__(cls, instance):
+        if cls.__subclasscheck__(type(instance)):
+            return True
+        # Also pretend that members of the extended enum are subclasses
+        # of the __base_enum__.  This is needed to circumvent error
+        # checking in enum.__new__ (e.g., for `ProblemSense('minimize')`)
+        return cls.__base_enum__.__subclasscheck__(type(instance))
+
+    def _missing_(cls, value):
+        # Support attribute lookup by value or name
+        for attr in ('value', 'name'):
+            for member in cls:
+                if getattr(member, attr) == value:
+                    return member
+        return None
+
+    def __new__(metacls, cls, bases, classdict, **kwds):
+        # Support lookup by name - but only if the new Enum doesn't
+        # specify its own implementation of _missing_
+        if '_missing_' not in classdict:
+            classdict['_missing_'] = classmethod(ExtendedEnumType._missing_)
+        return super().__new__(metacls, cls, bases, classdict, **kwds)
+
+
+class NamedIntEnum(enum.IntEnum):
+    """An extended version of :py:class:`enum.IntEnum` that supports
+    creating members by name as well as value.
+
+    """
+
+    @classmethod
+    def _missing_(cls, value):
+        for member in cls:
+            if member.name == value:
+                return member
+        return None
+
+
+class ObjectiveSense(NamedIntEnum):
+    """Flag indicating if an objective is minimizing (1) or maximizing (-1).
+
+    While the numeric values are arbitrary, there are parts of Pyomo
+    that rely on this particular choice of value.  These values are also
+    consistent with some solvers (notably Gurobi).
+
+    """
+
+    minimize = 1
+    maximize = -1
+
+    # Overloading __str__ is needed to match the behavior of the old
+    # pyutilib.enum class (removed June 2020). There are spots in the
+    # code base that expect the string representation for items in the
+    # enum to not include the class name. New uses of enum shouldn't
+    # need to do this.
+    def __str__(self):
+        return self.name
+
+
+minimize = ObjectiveSense.minimize
+maximize = ObjectiveSense.maximize
diff --git a/pyomo/common/env.py b/pyomo/common/env.py
index 2ce0f368b9e..ee07cdc1e6a 100644
--- a/pyomo/common/env.py
+++ b/pyomo/common/env.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/envvar.py b/pyomo/common/envvar.py
index d74cb764641..1f933d4b08c 100644
--- a/pyomo/common/envvar.py
+++ b/pyomo/common/envvar.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/errors.py b/pyomo/common/errors.py
index 17013ce4dca..3c82f2b07c1 100644
--- a/pyomo/common/errors.py
+++ b/pyomo/common/errors.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/extensions.py b/pyomo/common/extensions.py
index e4f7b047bb3..0ac27f125a7 100644
--- a/pyomo/common/extensions.py
+++ b/pyomo/common/extensions.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/factory.py b/pyomo/common/factory.py
index 6a97759c714..c449cf826b4 100644
--- a/pyomo/common/factory.py
+++ b/pyomo/common/factory.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/fileutils.py b/pyomo/common/fileutils.py
index 557901c401e..7b6520327a0 100644
--- a/pyomo/common/fileutils.py
+++ b/pyomo/common/fileutils.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -38,6 +38,7 @@
 import os
 import platform
 import importlib.util
+import subprocess
 import sys
 
 from . import envvar
@@ -375,9 +376,27 @@ def find_library(libname, cwd=True, include_PATH=True, pathlist=None):
     if libname_base.startswith('lib') and _system() != 'windows':
         libname_base = libname_base[3:]
     if ext.lower().startswith(('.so', '.dll', '.dylib')):
-        return ctypes.util.find_library(libname_base)
+        lib = ctypes.util.find_library(libname_base)
     else:
-        return ctypes.util.find_library(libname)
+        lib = ctypes.util.find_library(libname)
+    if lib and os.path.sep not in lib:
+        # work around https://github.com/python/cpython/issues/65241,
+        # where python does not return the absolute path on *nix
+        try:
+            libname = lib + ' '
+            with subprocess.Popen(
+                ['/sbin/ldconfig', '-p'],
+                stdin=subprocess.DEVNULL,
+                stderr=subprocess.DEVNULL,
+                stdout=subprocess.PIPE,
+                env={'LC_ALL': 'C', 'LANG': 'C'},
+            ) as p:
+                for line in os.fsdecode(p.stdout.read()).splitlines():
+                    if line.lstrip().startswith(libname):
+                        return os.path.realpath(line.split()[-1])
+        except:
+            pass
+    return lib
 
 
 def find_executable(exename, cwd=True, include_PATH=True, pathlist=None):
diff --git a/pyomo/common/formatting.py b/pyomo/common/formatting.py
index 5c2b329ce21..430ec96ca09 100644
--- a/pyomo/common/formatting.py
+++ b/pyomo/common/formatting.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/gc_manager.py b/pyomo/common/gc_manager.py
index 54fbca32736..751eb95cf18 100644
--- a/pyomo/common/gc_manager.py
+++ b/pyomo/common/gc_manager.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/getGSL.py b/pyomo/common/getGSL.py
index e8b2507ab81..66b75b45665 100644
--- a/pyomo/common/getGSL.py
+++ b/pyomo/common/getGSL.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/gsl.py b/pyomo/common/gsl.py
index 5243758a0de..96fab8623b3 100644
--- a/pyomo/common/gsl.py
+++ b/pyomo/common/gsl.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -23,8 +23,8 @@
 )
 def get_gsl(downloader):
     logger.info(
-        "As of February 9, 2023, AMPL GSL can no longer be downloaded\
-        through download-extensions. Visit https://portal.ampl.com/\
+        "As of February 9, 2023, AMPL GSL can no longer be downloaded \
+        through download-extensions. Visit https://portal.ampl.com/ \
         to download the AMPL GSL binaries."
     )
 
diff --git a/pyomo/common/log.py b/pyomo/common/log.py
index 3097fe1c6de..d61ed62f373 100644
--- a/pyomo/common/log.py
+++ b/pyomo/common/log.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/modeling.py b/pyomo/common/modeling.py
index 5ecc56cce9b..4c07048d77a 100644
--- a/pyomo/common/modeling.py
+++ b/pyomo/common/modeling.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/multithread.py b/pyomo/common/multithread.py
index 415d8aaba7e..a2dace2be0f 100644
--- a/pyomo/common/multithread.py
+++ b/pyomo/common/multithread.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from collections import defaultdict
 from threading import get_ident, main_thread
 
diff --git a/pyomo/common/numeric_types.py b/pyomo/common/numeric_types.py
index 19718b308b6..2b63038e125 100644
--- a/pyomo/common/numeric_types.py
+++ b/pyomo/common/numeric_types.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -12,7 +12,6 @@
 import logging
 import sys
 
-from pyomo.common.dependencies import numpy_available
 from pyomo.common.deprecation import deprecated, relocated_module_attribute
 from pyomo.common.errors import TemplateExpressionError
 
@@ -50,7 +49,6 @@
 native_integer_types = {int}
 native_logical_types = {bool}
 native_complex_types = {complex}
-pyomo_constant_types = set()  # includes NumericConstant
 
 _native_boolean_types = {int, bool, str, bytes}
 relocated_module_attribute(
@@ -62,6 +60,16 @@
     "be treated as if they were bool (as was the case for the other "
     "native_*_types sets).  Users likely should use native_logical_types.",
 )
+_pyomo_constant_types = set()  # includes NumericConstant, _PythonCallbackFunctionID
+relocated_module_attribute(
+    'pyomo_constant_types',
+    'pyomo.common.numeric_types._pyomo_constant_types',
+    version='6.7.2',
+    msg="The pyomo_constant_types set will be removed in the future: the set "
+    "contained only NumericConstant and _PythonCallbackFunctionID, and provided "
+    "no meaningful value to clients or walkers.  Users should likely handle "
+    "these types in the same manner as immutable Params.",
+)
 
 
 #: Python set used to identify numeric constants and related native
@@ -194,6 +202,67 @@ def RegisterLogicalType(new_type: type):
     nonpyomo_leaf_types.add(new_type)
 
 
+def check_if_native_type(obj):
+    if isinstance(obj, (str, bytes)):
+        native_types.add(obj.__class__)
+        return True
+    if check_if_logical_type(obj):
+        return True
+    if check_if_numeric_type(obj):
+        return True
+    return False
+
+
+def check_if_logical_type(obj):
+    """Test if the argument behaves like a logical type.
+
+    We check for "logical types" by checking if the type returns sane
+    results for Boolean operators (``^``, ``|``, ``&``) and if it maps
+    ``1`` and ``2`` both to the same equivalent instance.  If that
+    works, then we register the type in :py:attr:`native_logical_types`.
+
+    """
+    obj_class = obj.__class__
+    # Do not re-evaluate known native types
+    if obj_class in native_types:
+        return obj_class in native_logical_types
+
+    try:
+        # It is not an error if you can't initialize the type from an
+        # int, but if you can, it should map !0 to True
+        if obj_class(1) != obj_class(2):
+            return False
+    except:
+        pass
+
+    try:
+        # Native logical types *must* be hashable
+        hash(obj)
+        # Native logical types must honor standard Boolean operators
+        if all(
+            (
+                obj_class(False) != obj_class(True),
+                obj_class(False) ^ obj_class(False) == obj_class(False),
+                obj_class(False) ^ obj_class(True) == obj_class(True),
+                obj_class(True) ^ obj_class(False) == obj_class(True),
+                obj_class(True) ^ obj_class(True) == obj_class(False),
+                obj_class(False) | obj_class(False) == obj_class(False),
+                obj_class(False) | obj_class(True) == obj_class(True),
+                obj_class(True) | obj_class(False) == obj_class(True),
+                obj_class(True) | obj_class(True) == obj_class(True),
+                obj_class(False) & obj_class(False) == obj_class(False),
+                obj_class(False) & obj_class(True) == obj_class(False),
+                obj_class(True) & obj_class(False) == obj_class(False),
+                obj_class(True) & obj_class(True) == obj_class(True),
+            )
+        ):
+            RegisterLogicalType(obj_class)
+            return True
+    except:
+        pass
+    return False
+
+
 def check_if_numeric_type(obj):
     """Test if the argument behaves like a numeric type.
 
@@ -208,46 +277,55 @@ def check_if_numeric_type(obj):
     if obj_class in native_types:
         return obj_class in native_numeric_types
 
-    if 'numpy' in obj_class.__module__:
-        # trigger the resolution of numpy_available and check if this
-        # type was automatically registered
-        bool(numpy_available)
-        if obj_class in native_types:
-            return obj_class in native_numeric_types
-
     try:
         obj_plus_0 = obj + 0
         obj_p0_class = obj_plus_0.__class__
-        # ensure that the object is comparable to 0 in a meaningful way
-        # (among other things, this prevents numpy.ndarray objects from
-        # being added to native_numeric_types)
+        # Native numeric types *must* be hashable
+        hash(obj)
+    except:
+        return False
+    if obj_p0_class is not obj_class and obj_p0_class not in native_numeric_types:
+        return False
+    #
+    # Check if the numeric type behaves like a complex type
+    #
+    try:
+        if 1.41 < abs(obj_class(1j + 1)) < 1.42:
+            RegisterComplexType(obj_class)
+            return False
+    except:
+        pass
+    #
+    # Ensure that the object is comparable to 0 in a meaningful way
+    #
+    try:
         if not ((obj < 0) ^ (obj >= 0)):
             return False
-        # Native types *must* be hashable
-        hash(obj)
     except:
         return False
-    if obj_p0_class is obj_class or obj_p0_class in native_numeric_types:
-        #
-        # If we get here, this is a reasonably well-behaving
-        # numeric type: add it to the native numeric types
-        # so that future lookups will be faster.
-        #
-        RegisterNumericType(obj_class)
-        #
-        # Generate a warning, since Pyomo's management of third-party
-        # numeric types is more robust when registering explicitly.
-        #
-        logger.warning(
-            f"""Dynamically registering the following numeric type:
+    #
+    # If we get here, this is a reasonably well-behaving
+    # numeric type: add it to the native numeric types
+    # so that future lookups will be faster.
+    #
+    RegisterNumericType(obj_class)
+    try:
+        if obj_class(0.4) == obj_class(0):
+            RegisterIntegerType(obj_class)
+    except:
+        pass
+    #
+    # Generate a warning, since Pyomo's management of third-party
+    # numeric types is more robust when registering explicitly.
+    #
+    logger.warning(
+        f"""Dynamically registering the following numeric type:
     {obj_class.__module__}.{obj_class.__name__}
 Dynamic registration is supported for convenience, but there are known
 limitations to this approach.  We recommend explicitly registering
 numeric types using RegisterNumericType() or RegisterIntegerType()."""
-        )
-        return True
-    else:
-        return False
+    )
+    return True
 
 
 def value(obj, exception=True):
@@ -274,22 +352,10 @@ def value(obj, exception=True):
     """
     if obj.__class__ in native_types:
         return obj
-    if obj.__class__ in pyomo_constant_types:
-        #
-        # I'm commenting this out for now, but I think we should never expect
-        # to see a numeric constant with value None.
-        #
-        # if exception and obj.value is None:
-        #    raise ValueError(
-        #        "No value for uninitialized NumericConstant object %s"
-        #        % (obj.name,))
-        return obj.value
     #
     # Test if we have a duck typed Pyomo expression
     #
-    try:
-        obj.is_numeric_type()
-    except AttributeError:
+    if not hasattr(obj, 'is_numeric_type'):
         #
         # TODO: Historically we checked for new *numeric* types and
         # raised exceptions for anything else.  That is inconsistent
@@ -304,7 +370,7 @@ def value(obj, exception=True):
                 return None
             raise TypeError(
                 "Cannot evaluate object with unknown type: %s" % obj.__class__.__name__
-            ) from None
+            )
     #
     # Evaluate the expression object
     #
diff --git a/pyomo/common/plugin.py b/pyomo/common/plugin.py
index b48fa96a483..ac88388ebc0 100644
--- a/pyomo/common/plugin.py
+++ b/pyomo/common/plugin.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/plugin_base.py b/pyomo/common/plugin_base.py
index 67960ebbb12..75b8657d1a9 100644
--- a/pyomo/common/plugin_base.py
+++ b/pyomo/common/plugin_base.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/plugins.py b/pyomo/common/plugins.py
index 7db8077855a..ed44f8bf776 100644
--- a/pyomo/common/plugins.py
+++ b/pyomo/common/plugins.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/pyomo_typing.py b/pyomo/common/pyomo_typing.py
index 64ab2ddafc9..22ec3480842 100644
--- a/pyomo/common/pyomo_typing.py
+++ b/pyomo/common/pyomo_typing.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/shutdown.py b/pyomo/common/shutdown.py
index 5054fd21279..a96a6bc04fc 100644
--- a/pyomo/common/shutdown.py
+++ b/pyomo/common/shutdown.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import atexit
 
 
diff --git a/pyomo/common/sorting.py b/pyomo/common/sorting.py
index 31e796c6a9e..4f78a7892b8 100644
--- a/pyomo/common/sorting.py
+++ b/pyomo/common/sorting.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/tee.py b/pyomo/common/tee.py
index 029d66f5767..500f7b6f58d 100644
--- a/pyomo/common/tee.py
+++ b/pyomo/common/tee.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/tempfiles.py b/pyomo/common/tempfiles.py
index f51fad3f3ac..b9dface71b2 100644
--- a/pyomo/common/tempfiles.py
+++ b/pyomo/common/tempfiles.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/tests/__init__.py b/pyomo/common/tests/__init__.py
index bc8dfa27c9c..d8d8856e52f 100644
--- a/pyomo/common/tests/__init__.py
+++ b/pyomo/common/tests/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/tests/config_plugin.py b/pyomo/common/tests/config_plugin.py
index ada788fd7d4..6aebc40806a 100644
--- a/pyomo/common/tests/config_plugin.py
+++ b/pyomo/common/tests/config_plugin.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/tests/dep_mod.py b/pyomo/common/tests/dep_mod.py
index 54530393783..34c7219c6eb 100644
--- a/pyomo/common/tests/dep_mod.py
+++ b/pyomo/common/tests/dep_mod.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -13,8 +13,8 @@
 
 __version__ = '1.5'
 
-numpy, numpy_available = attempt_import('numpy', defer_check=True)
+numpy, numpy_available = attempt_import('numpy', defer_import=True)
 
 bogus_nonexisting_module, bogus_nonexisting_module_available = attempt_import(
-    'bogus_nonexisting_module', alt_names=['bogus_nem'], defer_check=True
+    'bogus_nonexisting_module', alt_names=['bogus_nem'], defer_import=True
 )
diff --git a/pyomo/common/tests/dep_mod_except.py b/pyomo/common/tests/dep_mod_except.py
index 8132e8a08ac..16936996eeb 100644
--- a/pyomo/common/tests/dep_mod_except.py
+++ b/pyomo/common/tests/dep_mod_except.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/tests/deps.py b/pyomo/common/tests/deps.py
index e5236d0f7ec..5f8c1fffdf8 100644
--- a/pyomo/common/tests/deps.py
+++ b/pyomo/common/tests/deps.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -23,15 +23,16 @@
     bogus_nonexisting_module_available as has_bogus_nem,
 )
 
-bogus, bogus_available = attempt_import('nonexisting.module.bogus', defer_check=True)
+bogus, bogus_available = attempt_import('nonexisting.module.bogus', defer_import=True)
 
 pkl_test, pkl_available = attempt_import(
-    'nonexisting.module.pickle_test', deferred_submodules=['submod'], defer_check=True
+    'nonexisting.module.pickle_test', deferred_submodules=['submod'], defer_import=True
 )
 
 pyo, pyo_available = attempt_import(
     'pyomo',
     alt_names=['pyo'],
+    defer_import=True,
     deferred_submodules={'version': None, 'common.tests.dep_mod': ['dm']},
 )
 
diff --git a/pyomo/common/tests/import_ex.py b/pyomo/common/tests/import_ex.py
index e19ad956044..73375bdc819 100644
--- a/pyomo/common/tests/import_ex.py
+++ b/pyomo/common/tests/import_ex.py
@@ -1,3 +1,15 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+
 def a():
     pass
 
diff --git a/pyomo/common/tests/relo_mod.py b/pyomo/common/tests/relo_mod.py
index 20b0712e09b..4881caba671 100644
--- a/pyomo/common/tests/relo_mod.py
+++ b/pyomo/common/tests/relo_mod.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/tests/relo_mod_new.py b/pyomo/common/tests/relo_mod_new.py
index 1ef27681b66..0f59f3beebc 100644
--- a/pyomo/common/tests/relo_mod_new.py
+++ b/pyomo/common/tests/relo_mod_new.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/tests/relocated.py b/pyomo/common/tests/relocated.py
index 9de63e0cec9..90cb28c23ba 100644
--- a/pyomo/common/tests/relocated.py
+++ b/pyomo/common/tests/relocated.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/tests/test_bunch.py b/pyomo/common/tests/test_bunch.py
index a8daf5a0071..8c10df83005 100644
--- a/pyomo/common/tests/test_bunch.py
+++ b/pyomo/common/tests/test_bunch.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/tests/test_component_map.py b/pyomo/common/tests/test_component_map.py
new file mode 100644
index 00000000000..7cd4ec2c458
--- /dev/null
+++ b/pyomo/common/tests/test_component_map.py
@@ -0,0 +1,90 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import pyomo.common.unittest as unittest
+
+from pyomo.common.collections import ComponentMap, ComponentSet, DefaultComponentMap
+from pyomo.environ import ConcreteModel, Block, Var, Constraint
+
+
+class TestComponentMap(unittest.TestCase):
+    def test_tuple(self):
+        m = ConcreteModel()
+        m.v = Var()
+        m.c = Constraint(expr=m.v >= 0)
+        m.cm = cm = ComponentMap()
+
+        cm[(1, 2)] = 5
+        self.assertEqual(len(cm), 1)
+        self.assertIn((1, 2), cm)
+        self.assertEqual(cm[1, 2], 5)
+
+        cm[(1, 2)] = 50
+        self.assertEqual(len(cm), 1)
+        self.assertIn((1, 2), cm)
+        self.assertEqual(cm[1, 2], 50)
+
+        cm[(1, (2, m.v))] = 10
+        self.assertEqual(len(cm), 2)
+        self.assertIn((1, (2, m.v)), cm)
+        self.assertEqual(cm[1, (2, m.v)], 10)
+
+        cm[(1, (2, m.v))] = 100
+        self.assertEqual(len(cm), 2)
+        self.assertIn((1, (2, m.v)), cm)
+        self.assertEqual(cm[1, (2, m.v)], 100)
+
+        i = m.clone()
+        self.assertIn((1, 2), i.cm)
+        self.assertIn((1, (2, i.v)), i.cm)
+        self.assertNotIn((1, (2, i.v)), m.cm)
+        self.assertIn((1, (2, m.v)), m.cm)
+        self.assertNotIn((1, (2, m.v)), i.cm)
+
+
+class TestDefaultComponentMap(unittest.TestCase):
+    def test_default_component_map(self):
+        dcm = DefaultComponentMap(ComponentSet)
+
+        m = ConcreteModel()
+        m.x = Var()
+        m.b = Block()
+        m.b.y = Var()
+
+        self.assertEqual(len(dcm), 0)
+
+        dcm[m.x].add(m)
+        self.assertEqual(len(dcm), 1)
+        self.assertIn(m.x, dcm)
+        self.assertIn(m, dcm[m.x])
+
+        dcm[m.b.y].add(m.b)
+        self.assertEqual(len(dcm), 2)
+        self.assertIn(m.b.y, dcm)
+        self.assertNotIn(m, dcm[m.b.y])
+        self.assertIn(m.b, dcm[m.b.y])
+
+        dcm[m.b.y].add(m)
+        self.assertEqual(len(dcm), 2)
+        self.assertIn(m.b.y, dcm)
+        self.assertIn(m, dcm[m.b.y])
+        self.assertIn(m.b, dcm[m.b.y])
+
+    def test_no_default_factory(self):
+        dcm = DefaultComponentMap()
+
+        dcm['found'] = 5
+        self.assertEqual(len(dcm), 1)
+        self.assertIn('found', dcm)
+        self.assertEqual(dcm['found'], 5)
+
+        with self.assertRaisesRegex(KeyError, "'missing'"):
+            dcm["missing"]
diff --git a/pyomo/common/tests/test_config.py b/pyomo/common/tests/test_config.py
index 1b732d86c0a..a47f5e0d8af 100644
--- a/pyomo/common/tests/test_config.py
+++ b/pyomo/common/tests/test_config.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -60,6 +60,7 @@ def yaml_load(arg):
     NonPositiveFloat,
     NonNegativeFloat,
     In,
+    IsInstance,
     ListOf,
     Module,
     Path,
@@ -448,12 +449,85 @@ class TestEnum(enum.Enum):
         with self.assertRaisesRegex(ValueError, '.*invalid value'):
             cfg.enum = 'ITEM_THREE'
 
+    def test_IsInstance(self):
+        c = ConfigDict()
+        c.declare("val", ConfigValue(None, IsInstance(int)))
+        c.val = 1
+        self.assertEqual(c.val, 1)
+        exc_str = (
+            "Expected an instance of 'int', but received value 2.4 of type 'float'"
+        )
+        with self.assertRaisesRegex(ValueError, exc_str):
+            c.val = 2.4
+
+        class TestClass:
+            def __repr__(self):
+                return f"{TestClass.__name__}()"
+
+        c.declare("val2", ConfigValue(None, IsInstance(TestClass)))
+        testinst = TestClass()
+        c.val2 = testinst
+        self.assertEqual(c.val2, testinst)
+        exc_str = (
+            r"Expected an instance of 'TestClass', "
+            "but received value 2.4 of type 'float'"
+        )
+        with self.assertRaisesRegex(ValueError, exc_str):
+            c.val2 = 2.4
+
+        c.declare(
+            "val3",
+            ConfigValue(
+                None, IsInstance(int, TestClass, document_full_base_names=True)
+            ),
+        )
+        self.assertRegex(
+            c.get("val3").domain_name(), r"IsInstance\(int, .*\.TestClass\)"
+        )
+        c.val3 = 2
+        self.assertEqual(c.val3, 2)
+        exc_str = (
+            r"Expected an instance of one of these types: 'int', '.*\.TestClass'"
+            r", but received value 2.4 of type 'float'"
+        )
+        with self.assertRaisesRegex(ValueError, exc_str):
+            c.val3 = 2.4
+
+        c.declare(
+            "val4",
+            ConfigValue(
+                None, IsInstance(int, TestClass, document_full_base_names=False)
+            ),
+        )
+        self.assertEqual(c.get("val4").domain_name(), "IsInstance(int, TestClass)")
+        c.val4 = 2
+        self.assertEqual(c.val4, 2)
+        exc_str = (
+            r"Expected an instance of one of these types: 'int', 'TestClass'"
+            r", but received value 2.4 of type 'float'"
+        )
+        with self.assertRaisesRegex(ValueError, exc_str):
+            c.val4 = 2.4
+
     def test_Path(self):
         def norm(x):
             if cwd[1] == ':' and x[0] == '/':
                 x = cwd[:2] + x
             return x.replace('/', os.path.sep)
 
+        class ExamplePathLike:
+            def __init__(self, path_str_or_bytes):
+                self.path = path_str_or_bytes
+
+            def __fspath__(self):
+                return self.path
+
+            def __str__(self):
+                path_str = str(self.path)
+                return f"{type(self).__name__}({path_str})"
+
+        self.assertEqual(Path().domain_name(), "Path")
+
         cwd = os.getcwd() + os.path.sep
         c = ConfigDict()
 
@@ -462,12 +536,30 @@ def norm(x):
         c.a = "/a/b/c"
         self.assertTrue(os.path.sep in c.a)
         self.assertEqual(c.a, norm('/a/b/c'))
+        c.a = b"/a/b/c"
+        self.assertTrue(os.path.sep in c.a)
+        self.assertEqual(c.a, norm('/a/b/c'))
+        c.a = ExamplePathLike("/a/b/c")
+        self.assertTrue(os.path.sep in c.a)
+        self.assertEqual(c.a, norm('/a/b/c'))
         c.a = "a/b/c"
         self.assertTrue(os.path.sep in c.a)
         self.assertEqual(c.a, norm(cwd + 'a/b/c'))
+        c.a = b'a/b/c'
+        self.assertTrue(os.path.sep in c.a)
+        self.assertEqual(c.a, norm(cwd + 'a/b/c'))
+        c.a = ExamplePathLike('a/b/c')
+        self.assertTrue(os.path.sep in c.a)
+        self.assertEqual(c.a, norm(cwd + 'a/b/c'))
         c.a = "${CWD}/a/b/c"
         self.assertTrue(os.path.sep in c.a)
         self.assertEqual(c.a, norm(cwd + 'a/b/c'))
+        c.a = b'${CWD}/a/b/c'
+        self.assertTrue(os.path.sep in c.a)
+        self.assertEqual(c.a, norm(cwd + 'a/b/c'))
+        c.a = ExamplePathLike('${CWD}/a/b/c')
+        self.assertTrue(os.path.sep in c.a)
+        self.assertEqual(c.a, norm(cwd + 'a/b/c'))
         c.a = None
         self.assertIs(c.a, None)
 
@@ -476,12 +568,30 @@ def norm(x):
         c.b = "/a/b/c"
         self.assertTrue(os.path.sep in c.b)
         self.assertEqual(c.b, norm('/a/b/c'))
+        c.b = b"/a/b/c"
+        self.assertTrue(os.path.sep in c.b)
+        self.assertEqual(c.b, norm('/a/b/c'))
+        c.b = ExamplePathLike("/a/b/c")
+        self.assertTrue(os.path.sep in c.b)
+        self.assertEqual(c.b, norm('/a/b/c'))
         c.b = "a/b/c"
         self.assertTrue(os.path.sep in c.b)
         self.assertEqual(c.b, norm(cwd + 'rel/path/a/b/c'))
+        c.b = b"a/b/c"
+        self.assertTrue(os.path.sep in c.b)
+        self.assertEqual(c.b, norm(cwd + 'rel/path/a/b/c'))
+        c.b = ExamplePathLike("a/b/c")
+        self.assertTrue(os.path.sep in c.b)
+        self.assertEqual(c.b, norm(cwd + "rel/path/a/b/c"))
         c.b = "${CWD}/a/b/c"
         self.assertTrue(os.path.sep in c.b)
         self.assertEqual(c.b, norm(cwd + 'a/b/c'))
+        c.b = b"${CWD}/a/b/c"
+        self.assertTrue(os.path.sep in c.b)
+        self.assertEqual(c.b, norm(cwd + 'a/b/c'))
+        c.b = ExamplePathLike("${CWD}/a/b/c")
+        self.assertTrue(os.path.sep in c.b)
+        self.assertEqual(c.b, norm(cwd + 'a/b/c'))
         c.b = None
         self.assertIs(c.b, None)
 
@@ -490,12 +600,30 @@ def norm(x):
         c.c = "/a/b/c"
         self.assertTrue(os.path.sep in c.c)
         self.assertEqual(c.c, norm('/a/b/c'))
+        c.c = b"/a/b/c"
+        self.assertTrue(os.path.sep in c.c)
+        self.assertEqual(c.c, norm('/a/b/c'))
+        c.c = ExamplePathLike("/a/b/c")
+        self.assertTrue(os.path.sep in c.c)
+        self.assertEqual(c.c, norm('/a/b/c'))
         c.c = "a/b/c"
         self.assertTrue(os.path.sep in c.c)
         self.assertEqual(c.c, norm('/my/dir/a/b/c'))
+        c.c = b"a/b/c"
+        self.assertTrue(os.path.sep in c.c)
+        self.assertEqual(c.c, norm('/my/dir/a/b/c'))
+        c.c = ExamplePathLike("a/b/c")
+        self.assertTrue(os.path.sep in c.c)
+        self.assertEqual(c.c, norm("/my/dir/a/b/c"))
         c.c = "${CWD}/a/b/c"
         self.assertTrue(os.path.sep in c.c)
         self.assertEqual(c.c, norm(cwd + 'a/b/c'))
+        c.c = b"${CWD}/a/b/c"
+        self.assertTrue(os.path.sep in c.c)
+        self.assertEqual(c.c, norm(cwd + 'a/b/c'))
+        c.c = ExamplePathLike("${CWD}/a/b/c")
+        self.assertTrue(os.path.sep in c.c)
+        self.assertEqual(c.c, norm(cwd + 'a/b/c'))
         c.c = None
         self.assertIs(c.c, None)
 
@@ -505,12 +633,30 @@ def norm(x):
         c.d = "/a/b/c"
         self.assertTrue(os.path.sep in c.d)
         self.assertEqual(c.d, norm('/a/b/c'))
+        c.d = b"/a/b/c"
+        self.assertTrue(os.path.sep in c.d)
+        self.assertEqual(c.d, norm('/a/b/c'))
+        c.d = ExamplePathLike("/a/b/c")
+        self.assertTrue(os.path.sep in c.d)
+        self.assertEqual(c.d, norm('/a/b/c'))
         c.d = "a/b/c"
         self.assertTrue(os.path.sep in c.d)
         self.assertEqual(c.d, norm(cwd + 'a/b/c'))
+        c.d = b"a/b/c"
+        self.assertTrue(os.path.sep in c.d)
+        self.assertEqual(c.d, norm(cwd + 'a/b/c'))
+        c.d = ExamplePathLike("a/b/c")
+        self.assertTrue(os.path.sep in c.d)
+        self.assertEqual(c.d, norm(cwd + 'a/b/c'))
         c.d = "${CWD}/a/b/c"
         self.assertTrue(os.path.sep in c.d)
         self.assertEqual(c.d, norm(cwd + 'a/b/c'))
+        c.d = b"${CWD}/a/b/c"
+        self.assertTrue(os.path.sep in c.d)
+        self.assertEqual(c.d, norm(cwd + 'a/b/c'))
+        c.d = ExamplePathLike("${CWD}/a/b/c")
+        self.assertTrue(os.path.sep in c.d)
+        self.assertEqual(c.d, norm(cwd + 'a/b/c'))
 
         c.d_base = '/my/dir'
         c.d = "/a/b/c"
@@ -527,12 +673,30 @@ def norm(x):
         c.d = "/a/b/c"
         self.assertTrue(os.path.sep in c.d)
         self.assertEqual(c.d, norm('/a/b/c'))
+        c.d = b"/a/b/c"
+        self.assertTrue(os.path.sep in c.d)
+        self.assertEqual(c.d, norm('/a/b/c'))
+        c.d = ExamplePathLike("/a/b/c")
+        self.assertTrue(os.path.sep in c.d)
+        self.assertEqual(c.d, norm('/a/b/c'))
         c.d = "a/b/c"
         self.assertTrue(os.path.sep in c.d)
         self.assertEqual(c.d, norm(cwd + 'rel/path/a/b/c'))
+        c.d = b"a/b/c"
+        self.assertTrue(os.path.sep in c.d)
+        self.assertEqual(c.d, norm(cwd + 'rel/path/a/b/c'))
+        c.d = ExamplePathLike("a/b/c")
+        self.assertTrue(os.path.sep in c.d)
+        self.assertEqual(c.d, norm(cwd + 'rel/path/a/b/c'))
         c.d = "${CWD}/a/b/c"
         self.assertTrue(os.path.sep in c.d)
         self.assertEqual(c.d, norm(cwd + 'a/b/c'))
+        c.d = b"${CWD}/a/b/c"
+        self.assertTrue(os.path.sep in c.d)
+        self.assertEqual(c.d, norm(cwd + 'a/b/c'))
+        c.d = ExamplePathLike("${CWD}/a/b/c")
+        self.assertTrue(os.path.sep in c.d)
+        self.assertEqual(c.d, norm(cwd + 'a/b/c'))
 
         try:
             Path.SuppressPathExpansion = True
@@ -540,14 +704,38 @@ def norm(x):
             self.assertTrue('/' in c.d)
             self.assertTrue('\\' not in c.d)
             self.assertEqual(c.d, '/a/b/c')
+            c.d = b"/a/b/c"
+            self.assertTrue('/' in c.d)
+            self.assertTrue('\\' not in c.d)
+            self.assertEqual(c.d, '/a/b/c')
+            c.d = ExamplePathLike("/a/b/c")
+            self.assertTrue('/' in c.d)
+            self.assertTrue('\\' not in c.d)
+            self.assertEqual(c.d, '/a/b/c')
             c.d = "a/b/c"
             self.assertTrue('/' in c.d)
             self.assertTrue('\\' not in c.d)
             self.assertEqual(c.d, 'a/b/c')
+            c.d = b"a/b/c"
+            self.assertTrue('/' in c.d)
+            self.assertTrue('\\' not in c.d)
+            self.assertEqual(c.d, 'a/b/c')
+            c.d = ExamplePathLike("a/b/c")
+            self.assertTrue('/' in c.d)
+            self.assertTrue('\\' not in c.d)
+            self.assertEqual(c.d, 'a/b/c')
             c.d = "${CWD}/a/b/c"
             self.assertTrue('/' in c.d)
             self.assertTrue('\\' not in c.d)
             self.assertEqual(c.d, "${CWD}/a/b/c")
+            c.d = b"${CWD}/a/b/c"
+            self.assertTrue('/' in c.d)
+            self.assertTrue('\\' not in c.d)
+            self.assertEqual(c.d, "${CWD}/a/b/c")
+            c.d = ExamplePathLike("${CWD}/a/b/c")
+            self.assertTrue('/' in c.d)
+            self.assertTrue('\\' not in c.d)
+            self.assertEqual(c.d, "${CWD}/a/b/c")
         finally:
             Path.SuppressPathExpansion = False
 
@@ -560,6 +748,8 @@ def norm(x):
         cwd = os.getcwd() + os.path.sep
         c = ConfigDict()
 
+        self.assertEqual(PathList().domain_name(), "PathList")
+
         c.declare('a', ConfigValue(None, PathList()))
         self.assertEqual(c.a, None)
         c.a = "/a/b/c"
@@ -582,6 +772,13 @@ def norm(x):
         self.assertEqual(len(c.a), 0)
         self.assertIs(type(c.a), list)
 
+        exc_str = r".*expected str, bytes or os.PathLike.*int"
+
+        with self.assertRaisesRegex(ValueError, exc_str):
+            c.a = 2
+        with self.assertRaisesRegex(ValueError, exc_str):
+            c.a = ["/a/b/c", 2]
+
     def test_ListOf(self):
         c = ConfigDict()
         c.declare('a', ConfigValue(domain=ListOf(int), default=None))
@@ -1473,7 +1670,7 @@ def test_parseDisplay_userdata_add_block_nonDefault(self):
         self.config.add("bar", ConfigDict(implicit=True)).add("baz", ConfigDict())
         test = _display(self.config, 'userdata')
         sys.stdout.write(test)
-        self.assertEqual(yaml_load(test), {'bar': {'baz': None}, foo: 0})
+        self.assertEqual(yaml_load(test), {'bar': {'baz': None}, 'foo': 0})
 
     @unittest.skipIf(not yaml_available, "Test requires PyYAML")
     def test_parseDisplay_userdata_add_block(self):
@@ -1901,7 +2098,6 @@ def test_generate_custom_documentation(self):
                 "generate_documentation is deprecated.",
                 LOG,
             )
-        self.maxDiff = None
         # print(test)
         self.assertEqual(test, reference)
 
@@ -1916,7 +2112,6 @@ def test_generate_custom_documentation(self):
                 )
             )
         self.assertEqual(LOG.getvalue(), "")
-        self.maxDiff = None
         # print(test)
         self.assertEqual(test, reference)
 
@@ -1962,7 +2157,6 @@ def test_generate_custom_documentation(self):
                 "generate_documentation is deprecated.",
                 LOG,
             )
-        self.maxDiff = None
         # print(test)
         self.assertEqual(test, reference)
 
@@ -2380,7 +2574,6 @@ def test_argparse_help_implicit_disable(self):
         parser = argparse.ArgumentParser(prog='tester')
         self.config.initialize_argparse(parser)
         help = parser.format_help()
-        self.maxDiff = None
         self.assertIn(
             """
   -h, --help            show this help message and exit
@@ -2909,8 +3102,6 @@ def test_declare_from(self):
             cfg2.declare_from({})
 
     def test_docstring_decorator(self):
-        self.maxDiff = None
-
         @document_kwargs_from_configdict('CONFIG')
         class ExampleClass(object):
             CONFIG = ExampleConfig()
@@ -3068,6 +3259,41 @@ def __init__(
             OUT.getvalue().replace('null', 'None'),
         )
 
+    def test_domain_name(self):
+        cfg = ConfigDict()
+
+        cfg.declare('none', ConfigValue())
+        self.assertEqual(cfg.get('none').domain_name(), '')
+
+        def fcn(val):
+            return val
+
+        cfg.declare('fcn', ConfigValue(domain=fcn))
+        self.assertEqual(cfg.get('fcn').domain_name(), 'fcn')
+
+        fcn.domain_name = 'custom fcn'
+        self.assertEqual(cfg.get('fcn').domain_name(), 'custom fcn')
+
+        class functor:
+            def __call__(self, val):
+                return val
+
+        cfg.declare('functor', ConfigValue(domain=functor()))
+        self.assertEqual(cfg.get('functor').domain_name(), 'functor')
+
+        class cfunctor:
+            def __call__(self, val):
+                return val
+
+            def domain_name(self):
+                return 'custom functor'
+
+        cfg.declare('cfunctor', ConfigValue(domain=cfunctor()))
+        self.assertEqual(cfg.get('cfunctor').domain_name(), 'custom functor')
+
+        cfg.declare('type', ConfigValue(domain=int))
+        self.assertEqual(cfg.get('type').domain_name(), 'int')
+
 
 if __name__ == "__main__":
     unittest.main()
diff --git a/pyomo/common/tests/test_dependencies.py b/pyomo/common/tests/test_dependencies.py
index 65058e01812..6aedc428244 100644
--- a/pyomo/common/tests/test_dependencies.py
+++ b/pyomo/common/tests/test_dependencies.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -45,7 +45,7 @@ def test_import_error(self):
         module_obj, module_available = attempt_import(
             '__there_is_no_module_named_this__',
             'Testing import of a non-existent module',
-            defer_check=False,
+            defer_import=False,
         )
         self.assertFalse(module_available)
         with self.assertRaisesRegex(
@@ -85,7 +85,7 @@ def test_pickle(self):
 
     def test_import_success(self):
         module_obj, module_available = attempt_import(
-            'ply', 'Testing import of ply', defer_check=False
+            'ply', 'Testing import of ply', defer_import=False
         )
         self.assertTrue(module_available)
         import ply
@@ -123,7 +123,7 @@ def test_imported_deferred_import(self):
 
     def test_min_version(self):
         mod, avail = attempt_import(
-            'pyomo.common.tests.dep_mod', minimum_version='1.0', defer_check=False
+            'pyomo.common.tests.dep_mod', minimum_version='1.0', defer_import=False
         )
         self.assertTrue(avail)
         self.assertTrue(inspect.ismodule(mod))
@@ -131,7 +131,7 @@ def test_min_version(self):
         self.assertFalse(check_min_version(mod, '2.0'))
 
         mod, avail = attempt_import(
-            'pyomo.common.tests.dep_mod', minimum_version='2.0', defer_check=False
+            'pyomo.common.tests.dep_mod', minimum_version='2.0', defer_import=False
         )
         self.assertFalse(avail)
         self.assertIs(type(mod), ModuleUnavailable)
@@ -146,7 +146,7 @@ def test_min_version(self):
             'pyomo.common.tests.dep_mod',
             error_message="Failed import",
             minimum_version='2.0',
-            defer_check=False,
+            defer_import=False,
         )
         self.assertFalse(avail)
         self.assertIs(type(mod), ModuleUnavailable)
@@ -159,10 +159,10 @@ def test_min_version(self):
 
         # Verify check_min_version works with deferred imports
 
-        mod, avail = attempt_import('pyomo.common.tests.dep_mod', defer_check=True)
+        mod, avail = attempt_import('pyomo.common.tests.dep_mod', defer_import=True)
         self.assertTrue(check_min_version(mod, '1.0'))
 
-        mod, avail = attempt_import('pyomo.common.tests.dep_mod', defer_check=True)
+        mod, avail = attempt_import('pyomo.common.tests.dep_mod', defer_import=True)
         self.assertFalse(check_min_version(mod, '2.0'))
 
         # Verify check_min_version works when called directly
@@ -174,10 +174,10 @@ def test_min_version(self):
         self.assertFalse(check_min_version(mod, '1.0'))
 
     def test_and_or(self):
-        mod0, avail0 = attempt_import('ply', defer_check=True)
-        mod1, avail1 = attempt_import('pyomo.common.tests.dep_mod', defer_check=True)
+        mod0, avail0 = attempt_import('ply', defer_import=True)
+        mod1, avail1 = attempt_import('pyomo.common.tests.dep_mod', defer_import=True)
         mod2, avail2 = attempt_import(
-            'pyomo.common.tests.dep_mod', minimum_version='2.0', defer_check=True
+            'pyomo.common.tests.dep_mod', minimum_version='2.0', defer_import=True
         )
 
         _and = avail0 & avail1
@@ -209,7 +209,7 @@ def test_and_or(self):
         _and_or = avail0 & avail1 | avail2
         self.assertTrue(_and_or)
 
-        # Verify operator prescedence
+        # Verify operator precedence
         _or_and = avail0 | avail2 & avail2
         self.assertTrue(_or_and)
         _or_and = (avail0 | avail2) & avail2
@@ -233,11 +233,11 @@ def test_callbacks(self):
         def _record_avail(module, avail):
             ans.append(avail)
 
-        mod0, avail0 = attempt_import('ply', defer_check=True, callback=_record_avail)
+        mod0, avail0 = attempt_import('ply', defer_import=True, callback=_record_avail)
         mod1, avail1 = attempt_import(
             'pyomo.common.tests.dep_mod',
             minimum_version='2.0',
-            defer_check=True,
+            defer_import=True,
             callback=_record_avail,
         )
 
@@ -250,7 +250,7 @@ def _record_avail(module, avail):
     def test_import_exceptions(self):
         mod, avail = attempt_import(
             'pyomo.common.tests.dep_mod_except',
-            defer_check=True,
+            defer_import=True,
             only_catch_importerror=True,
         )
         with self.assertRaisesRegex(ValueError, "cannot import module"):
@@ -260,7 +260,7 @@ def test_import_exceptions(self):
 
         mod, avail = attempt_import(
             'pyomo.common.tests.dep_mod_except',
-            defer_check=True,
+            defer_import=True,
             only_catch_importerror=False,
         )
         self.assertFalse(avail)
@@ -268,7 +268,7 @@ def test_import_exceptions(self):
 
         mod, avail = attempt_import(
             'pyomo.common.tests.dep_mod_except',
-            defer_check=True,
+            defer_import=True,
             catch_exceptions=(ImportError, ValueError),
         )
         self.assertFalse(avail)
@@ -280,7 +280,7 @@ def test_import_exceptions(self):
         ):
             mod, avail = attempt_import(
                 'pyomo.common.tests.dep_mod_except',
-                defer_check=True,
+                defer_import=True,
                 only_catch_importerror=True,
                 catch_exceptions=(ImportError,),
             )
@@ -288,7 +288,7 @@ def test_import_exceptions(self):
     def test_generate_warning(self):
         mod, avail = attempt_import(
             'pyomo.common.tests.dep_mod_except',
-            defer_check=True,
+            defer_import=True,
             only_catch_importerror=False,
         )
 
@@ -324,7 +324,7 @@ def test_generate_warning(self):
     def test_log_warning(self):
         mod, avail = attempt_import(
             'pyomo.common.tests.dep_mod_except',
-            defer_check=True,
+            defer_import=True,
             only_catch_importerror=False,
         )
         log = StringIO()
@@ -366,9 +366,9 @@ def test_importer(self):
 
         def _importer():
             attempted_import.append(True)
-            return attempt_import('pyomo.common.tests.dep_mod', defer_check=False)[0]
+            return attempt_import('pyomo.common.tests.dep_mod', defer_import=False)[0]
 
-        mod, avail = attempt_import('foo', importer=_importer, defer_check=True)
+        mod, avail = attempt_import('foo', importer=_importer, defer_import=True)
 
         self.assertEqual(attempted_import, [])
         self.assertIsInstance(mod, DeferredImportModule)
@@ -401,17 +401,17 @@ def test_deferred_submodules(self):
         self.assertTrue(inspect.ismodule(deps.dm))
 
         with self.assertRaisesRegex(
-            ValueError, "deferred_submodules is only valid if defer_check==True"
+            ValueError, "deferred_submodules is only valid if defer_import==True"
         ):
             mod, mod_available = attempt_import(
                 'nonexisting.module',
-                defer_check=False,
+                defer_import=False,
                 deferred_submodules={'submod': None},
             )
 
         mod, mod_available = attempt_import(
             'nonexisting.module',
-            defer_check=True,
+            defer_import=True,
             deferred_submodules={'submod.subsubmod': None},
         )
         self.assertIs(type(mod), DeferredImportModule)
@@ -427,7 +427,7 @@ def test_UnavailableClass(self):
         module_obj, module_available = attempt_import(
             '__there_is_no_module_named_this__',
             'Testing import of a non-existent module',
-            defer_check=False,
+            defer_import=False,
         )
 
         class A_Class(UnavailableClass(module_obj)):
diff --git a/pyomo/common/tests/test_deprecated.py b/pyomo/common/tests/test_deprecated.py
index 1fb4a471740..37e1ba81bb3 100644
--- a/pyomo/common/tests/test_deprecated.py
+++ b/pyomo/common/tests/test_deprecated.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -529,7 +529,10 @@ class DeprecatedClassSubclass(DeprecatedClass):
         out = StringIO()
         with LoggingIntercept(out):
 
-            class DeprecatedClassSubSubclass(DeprecatedClassSubclass):
+            class otherClass:
+                pass
+
+            class DeprecatedClassSubSubclass(DeprecatedClassSubclass, otherClass):
                 attr = 'DeprecatedClassSubSubclass'
 
         self.assertEqual(out.getvalue(), "")
diff --git a/pyomo/common/tests/test_download.py b/pyomo/common/tests/test_download.py
index 8c41edc1512..8fee0ba7e31 100644
--- a/pyomo/common/tests/test_download.py
+++ b/pyomo/common/tests/test_download.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,12 +9,14 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
+import io
 import os
 import platform
 import re
 import shutil
-import tempfile
 import subprocess
+import tarfile
+import tempfile
 
 import pyomo.common.unittest as unittest
 import pyomo.common.envvar as envvar
@@ -22,6 +24,7 @@
 from pyomo.common import DeveloperError
 from pyomo.common.fileutils import this_file
 from pyomo.common.download import FileDownloader, distro_available
+from pyomo.common.log import LoggingIntercept
 from pyomo.common.tee import capture_output
 
 
@@ -242,7 +245,7 @@ def test_get_files_requires_set_destination(self):
         ):
             f.get_gzipped_binary_file('bogus')
 
-    def test_get_test_binary_file(self):
+    def test_get_text_binary_file(self):
         tmpdir = tempfile.mkdtemp()
         try:
             f = FileDownloader()
@@ -263,3 +266,66 @@ def test_get_test_binary_file(self):
             self.assertEqual(os.path.getsize(target), len(os.linesep))
         finally:
             shutil.rmtree(tmpdir)
+
+    def test_get_tar_archive(self):
+        tmpdir = tempfile.mkdtemp()
+        try:
+            f = FileDownloader()
+
+            # Mock retrieve_url so network connections are not necessary
+            buf = io.BytesIO()
+            with tarfile.open(mode="w:gz", fileobj=buf) as TAR:
+                info = tarfile.TarInfo('b/lnk')
+                info.size = 0
+                info.type = tarfile.SYMTYPE
+                info.linkname = envvar.PYOMO_CONFIG_DIR
+                TAR.addfile(info)
+                for fname in ('a', 'b/c', 'b/d', '/root', 'b/lnk/test'):
+                    info = tarfile.TarInfo(fname)
+                    info.size = 0
+                    info.type = tarfile.REGTYPE
+                    info.mode = 0o644
+                    info.mtime = info.uid = info.gid = 0
+                    info.uname = info.gname = 'root'
+                    TAR.addfile(info)
+            f.retrieve_url = lambda url: buf.getvalue()
+
+            with self.assertRaisesRegex(
+                DeveloperError,
+                r"(?s)target file name has not been initialized "
+                r"with set_destination_filename".replace(' ', r'\s+'),
+            ):
+                f.get_tar_archive(None, 1)
+
+            _tmp = os.path.join(tmpdir, 'a_file')
+            with open(_tmp, 'w'):
+                pass
+            f.set_destination_filename(_tmp)
+            with self.assertRaisesRegex(
+                RuntimeError,
+                r"Target directory \(.*a_file\) exists, but is not a directory",
+            ):
+                f.get_tar_archive(None, 1)
+
+            f.set_destination_filename(tmpdir)
+            with LoggingIntercept() as LOG:
+                f.get_tar_archive(None, 1)
+
+            self.assertEqual(
+                LOG.getvalue().strip(),
+                """
+Skipping file (a) in tar archive due to dirOffset.
+malformed or potentially insecure filename (/root).  Skipping file.
+potentially insecure filename (lnk/test) resolves outside target directory.  Skipping file.
+""".strip(),
+            )
+            for f in ('c', 'd'):
+                fname = os.path.join(tmpdir, f)
+                self.assertTrue(os.path.exists(fname))
+                self.assertTrue(os.path.isfile(fname))
+            for f in ('lnk',):
+                fname = os.path.join(tmpdir, f)
+                self.assertTrue(os.path.exists(fname))
+                self.assertTrue(os.path.islink(fname))
+        finally:
+            shutil.rmtree(tmpdir)
diff --git a/pyomo/common/tests/test_enums.py b/pyomo/common/tests/test_enums.py
new file mode 100644
index 00000000000..80d081505e9
--- /dev/null
+++ b/pyomo/common/tests/test_enums.py
@@ -0,0 +1,97 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import enum
+
+import pyomo.common.unittest as unittest
+
+from pyomo.common.enums import ExtendedEnumType, ObjectiveSense
+
+
+class ProblemSense(enum.IntEnum, metaclass=ExtendedEnumType):
+    __base_enum__ = ObjectiveSense
+
+    unknown = 0
+
+
+class TestExtendedEnumType(unittest.TestCase):
+    def test_members(self):
+        self.assertEqual(
+            list(ProblemSense),
+            [ProblemSense.unknown, ObjectiveSense.minimize, ObjectiveSense.maximize],
+        )
+
+    def test_isinstance(self):
+        self.assertIsInstance(ProblemSense.unknown, ProblemSense)
+        self.assertIsInstance(ProblemSense.minimize, ProblemSense)
+        self.assertIsInstance(ProblemSense.maximize, ProblemSense)
+
+        self.assertTrue(ProblemSense.__instancecheck__(ProblemSense.unknown))
+        self.assertTrue(ProblemSense.__instancecheck__(ProblemSense.minimize))
+        self.assertTrue(ProblemSense.__instancecheck__(ProblemSense.maximize))
+
+    def test_getattr(self):
+        self.assertIs(ProblemSense.unknown, ProblemSense.unknown)
+        self.assertIs(ProblemSense.minimize, ObjectiveSense.minimize)
+        self.assertIs(ProblemSense.maximize, ObjectiveSense.maximize)
+
+    def test_hasattr(self):
+        self.assertTrue(hasattr(ProblemSense, 'unknown'))
+        self.assertTrue(hasattr(ProblemSense, 'minimize'))
+        self.assertTrue(hasattr(ProblemSense, 'maximize'))
+
+    def test_call(self):
+        self.assertIs(ProblemSense(0), ProblemSense.unknown)
+        self.assertIs(ProblemSense(1), ObjectiveSense.minimize)
+        self.assertIs(ProblemSense(-1), ObjectiveSense.maximize)
+
+        self.assertIs(ProblemSense('unknown'), ProblemSense.unknown)
+        self.assertIs(ProblemSense('minimize'), ObjectiveSense.minimize)
+        self.assertIs(ProblemSense('maximize'), ObjectiveSense.maximize)
+
+        with self.assertRaisesRegex(ValueError, "'foo' is not a valid ProblemSense"):
+            ProblemSense('foo')
+        with self.assertRaisesRegex(ValueError, "2 is not a valid ProblemSense"):
+            ProblemSense(2)
+
+    def test_contains(self):
+        self.assertIn(ProblemSense.unknown, ProblemSense)
+        self.assertIn(ProblemSense.minimize, ProblemSense)
+        self.assertIn(ProblemSense.maximize, ProblemSense)
+
+        self.assertNotIn(ProblemSense.unknown, ObjectiveSense)
+        self.assertIn(ProblemSense.minimize, ObjectiveSense)
+        self.assertIn(ProblemSense.maximize, ObjectiveSense)
+
+
+class TestObjectiveSense(unittest.TestCase):
+    def test_members(self):
+        self.assertEqual(
+            list(ObjectiveSense), [ObjectiveSense.minimize, ObjectiveSense.maximize]
+        )
+
+    def test_hasattr(self):
+        self.assertTrue(hasattr(ProblemSense, 'minimize'))
+        self.assertTrue(hasattr(ProblemSense, 'maximize'))
+
+    def test_call(self):
+        self.assertIs(ObjectiveSense(1), ObjectiveSense.minimize)
+        self.assertIs(ObjectiveSense(-1), ObjectiveSense.maximize)
+
+        self.assertIs(ObjectiveSense('minimize'), ObjectiveSense.minimize)
+        self.assertIs(ObjectiveSense('maximize'), ObjectiveSense.maximize)
+
+        with self.assertRaisesRegex(ValueError, "'foo' is not a valid ObjectiveSense"):
+            ObjectiveSense('foo')
+
+    def test_str(self):
+        self.assertEqual(str(ObjectiveSense.minimize), 'minimize')
+        self.assertEqual(str(ObjectiveSense.maximize), 'maximize')
diff --git a/pyomo/common/tests/test_env.py b/pyomo/common/tests/test_env.py
index d14326ddc19..93802fc40bb 100644
--- a/pyomo/common/tests/test_env.py
+++ b/pyomo/common/tests/test_env.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/tests/test_errors.py b/pyomo/common/tests/test_errors.py
index ec77643f722..67a200e84e3 100644
--- a/pyomo/common/tests/test_errors.py
+++ b/pyomo/common/tests/test_errors.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/tests/test_fileutils.py b/pyomo/common/tests/test_fileutils.py
index 63570774e5b..068360b55cb 100644
--- a/pyomo/common/tests/test_fileutils.py
+++ b/pyomo/common/tests/test_fileutils.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/tests/test_formatting.py b/pyomo/common/tests/test_formatting.py
index d502c81da5a..29db26676ab 100644
--- a/pyomo/common/tests/test_formatting.py
+++ b/pyomo/common/tests/test_formatting.py
@@ -2,7 +2,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/tests/test_gc.py b/pyomo/common/tests/test_gc.py
index b2f23102a0e..176010b8d0d 100644
--- a/pyomo/common/tests/test_gc.py
+++ b/pyomo/common/tests/test_gc.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/tests/test_log.py b/pyomo/common/tests/test_log.py
index 39fab153e98..166e1e44cdb 100644
--- a/pyomo/common/tests/test_log.py
+++ b/pyomo/common/tests/test_log.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -511,7 +511,6 @@ def test_verbatim(self):
             "\n"
             "    quote block\n"
         )
-        self.maxDiff = None
         self.assertEqual(self.stream.getvalue(), ans)
 
 
diff --git a/pyomo/common/tests/test_modeling.py b/pyomo/common/tests/test_modeling.py
index 0684d77b2e9..97bef76c2c0 100644
--- a/pyomo/common/tests/test_modeling.py
+++ b/pyomo/common/tests/test_modeling.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/tests/test_multithread.py b/pyomo/common/tests/test_multithread.py
index ae1bc48be44..fa1a46fa25f 100644
--- a/pyomo/common/tests/test_multithread.py
+++ b/pyomo/common/tests/test_multithread.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import threading
 import pyomo.common.unittest as unittest
 from pyomo.common.multithread import *
diff --git a/pyomo/common/tests/test_numeric_types.py b/pyomo/common/tests/test_numeric_types.py
new file mode 100644
index 00000000000..b7ffb5fb255
--- /dev/null
+++ b/pyomo/common/tests/test_numeric_types.py
@@ -0,0 +1,219 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import pyomo.common.numeric_types as nt
+import pyomo.common.unittest as unittest
+
+from pyomo.common.dependencies import numpy, numpy_available
+from pyomo.core.expr import LinearExpression
+from pyomo.environ import Var
+
+_type_sets = (
+    'native_types',
+    'native_numeric_types',
+    'native_logical_types',
+    'native_integer_types',
+    'native_complex_types',
+)
+
+
+class TestNativeTypes(unittest.TestCase):
+    def setUp(self):
+        bool(numpy_available)
+        for s in _type_sets:
+            setattr(self, s, set(getattr(nt, s)))
+            getattr(nt, s).clear()
+
+    def tearDown(self):
+        for s in _type_sets:
+            getattr(nt, s).clear()
+            getattr(nt, s).update(getattr(self, s))
+
+    def test_check_if_native_type(self):
+        self.assertEqual(nt.native_types, set())
+        self.assertEqual(nt.native_logical_types, set())
+        self.assertEqual(nt.native_numeric_types, set())
+        self.assertEqual(nt.native_integer_types, set())
+        self.assertEqual(nt.native_complex_types, set())
+
+        self.assertTrue(nt.check_if_native_type("a"))
+        self.assertIn(str, nt.native_types)
+        self.assertNotIn(str, nt.native_logical_types)
+        self.assertNotIn(str, nt.native_numeric_types)
+        self.assertNotIn(str, nt.native_integer_types)
+        self.assertNotIn(str, nt.native_complex_types)
+
+        self.assertTrue(nt.check_if_native_type(1))
+        self.assertIn(int, nt.native_types)
+        self.assertNotIn(int, nt.native_logical_types)
+        self.assertIn(int, nt.native_numeric_types)
+        self.assertIn(int, nt.native_integer_types)
+        self.assertNotIn(int, nt.native_complex_types)
+
+        self.assertTrue(nt.check_if_native_type(1.5))
+        self.assertIn(float, nt.native_types)
+        self.assertNotIn(float, nt.native_logical_types)
+        self.assertIn(float, nt.native_numeric_types)
+        self.assertNotIn(float, nt.native_integer_types)
+        self.assertNotIn(float, nt.native_complex_types)
+
+        self.assertTrue(nt.check_if_native_type(True))
+        self.assertIn(bool, nt.native_types)
+        self.assertIn(bool, nt.native_logical_types)
+        self.assertNotIn(bool, nt.native_numeric_types)
+        self.assertNotIn(bool, nt.native_integer_types)
+        self.assertNotIn(bool, nt.native_complex_types)
+
+        self.assertFalse(nt.check_if_native_type(slice(None, None, None)))
+        self.assertNotIn(slice, nt.native_types)
+        self.assertNotIn(slice, nt.native_logical_types)
+        self.assertNotIn(slice, nt.native_numeric_types)
+        self.assertNotIn(slice, nt.native_integer_types)
+        self.assertNotIn(slice, nt.native_complex_types)
+
+    def test_check_if_logical_type(self):
+        self.assertEqual(nt.native_types, set())
+        self.assertEqual(nt.native_logical_types, set())
+        self.assertEqual(nt.native_numeric_types, set())
+        self.assertEqual(nt.native_integer_types, set())
+        self.assertEqual(nt.native_complex_types, set())
+
+        self.assertFalse(nt.check_if_logical_type("a"))
+        self.assertNotIn(str, nt.native_types)
+        self.assertNotIn(str, nt.native_logical_types)
+        self.assertNotIn(str, nt.native_numeric_types)
+        self.assertNotIn(str, nt.native_integer_types)
+        self.assertNotIn(str, nt.native_complex_types)
+
+        self.assertFalse(nt.check_if_logical_type("a"))
+
+        self.assertTrue(nt.check_if_logical_type(True))
+        self.assertIn(bool, nt.native_types)
+        self.assertIn(bool, nt.native_logical_types)
+        self.assertNotIn(bool, nt.native_numeric_types)
+        self.assertNotIn(bool, nt.native_integer_types)
+        self.assertNotIn(bool, nt.native_complex_types)
+
+        self.assertTrue(nt.check_if_logical_type(True))
+
+        self.assertFalse(nt.check_if_logical_type(1))
+        self.assertNotIn(int, nt.native_types)
+        self.assertNotIn(int, nt.native_logical_types)
+        self.assertNotIn(int, nt.native_numeric_types)
+        self.assertNotIn(int, nt.native_integer_types)
+        self.assertNotIn(int, nt.native_complex_types)
+
+        if numpy_available:
+            self.assertTrue(nt.check_if_logical_type(numpy.bool_(1)))
+            self.assertIn(numpy.bool_, nt.native_types)
+            self.assertIn(numpy.bool_, nt.native_logical_types)
+            self.assertNotIn(numpy.bool_, nt.native_numeric_types)
+            self.assertNotIn(numpy.bool_, nt.native_integer_types)
+            self.assertNotIn(numpy.bool_, nt.native_complex_types)
+
+    def test_check_if_numeric_type(self):
+        self.assertEqual(nt.native_types, set())
+        self.assertEqual(nt.native_logical_types, set())
+        self.assertEqual(nt.native_numeric_types, set())
+        self.assertEqual(nt.native_integer_types, set())
+        self.assertEqual(nt.native_complex_types, set())
+
+        self.assertFalse(nt.check_if_numeric_type("a"))
+        self.assertFalse(nt.check_if_numeric_type("a"))
+        self.assertNotIn(str, nt.native_types)
+        self.assertNotIn(str, nt.native_logical_types)
+        self.assertNotIn(str, nt.native_numeric_types)
+        self.assertNotIn(str, nt.native_integer_types)
+        self.assertNotIn(str, nt.native_complex_types)
+
+        self.assertFalse(nt.check_if_numeric_type(True))
+        self.assertFalse(nt.check_if_numeric_type(True))
+        self.assertNotIn(bool, nt.native_types)
+        self.assertNotIn(bool, nt.native_logical_types)
+        self.assertNotIn(bool, nt.native_numeric_types)
+        self.assertNotIn(bool, nt.native_integer_types)
+        self.assertNotIn(bool, nt.native_complex_types)
+
+        self.assertTrue(nt.check_if_numeric_type(1))
+        self.assertTrue(nt.check_if_numeric_type(1))
+        self.assertIn(int, nt.native_types)
+        self.assertNotIn(int, nt.native_logical_types)
+        self.assertIn(int, nt.native_numeric_types)
+        self.assertIn(int, nt.native_integer_types)
+        self.assertNotIn(int, nt.native_complex_types)
+
+        self.assertTrue(nt.check_if_numeric_type(1.5))
+        self.assertTrue(nt.check_if_numeric_type(1.5))
+        self.assertIn(float, nt.native_types)
+        self.assertNotIn(float, nt.native_logical_types)
+        self.assertIn(float, nt.native_numeric_types)
+        self.assertNotIn(float, nt.native_integer_types)
+        self.assertNotIn(float, nt.native_complex_types)
+
+        self.assertFalse(nt.check_if_numeric_type(1j))
+        self.assertIn(complex, nt.native_types)
+        self.assertNotIn(complex, nt.native_logical_types)
+        self.assertNotIn(complex, nt.native_numeric_types)
+        self.assertNotIn(complex, nt.native_integer_types)
+        self.assertIn(complex, nt.native_complex_types)
+
+        v = Var()
+        v.construct()
+        self.assertFalse(nt.check_if_numeric_type(v))
+        self.assertNotIn(type(v), nt.native_types)
+        self.assertNotIn(type(v), nt.native_logical_types)
+        self.assertNotIn(type(v), nt.native_numeric_types)
+        self.assertNotIn(type(v), nt.native_integer_types)
+        self.assertNotIn(type(v), nt.native_complex_types)
+
+        e = LinearExpression([1])
+        self.assertFalse(nt.check_if_numeric_type(e))
+        self.assertNotIn(type(e), nt.native_types)
+        self.assertNotIn(type(e), nt.native_logical_types)
+        self.assertNotIn(type(e), nt.native_numeric_types)
+        self.assertNotIn(type(e), nt.native_integer_types)
+        self.assertNotIn(type(e), nt.native_complex_types)
+
+        if numpy_available:
+            self.assertFalse(nt.check_if_numeric_type(numpy.bool_(1)))
+            self.assertNotIn(numpy.bool_, nt.native_types)
+            self.assertNotIn(numpy.bool_, nt.native_logical_types)
+            self.assertNotIn(numpy.bool_, nt.native_numeric_types)
+            self.assertNotIn(numpy.bool_, nt.native_integer_types)
+            self.assertNotIn(numpy.bool_, nt.native_complex_types)
+
+            self.assertFalse(nt.check_if_numeric_type(numpy.array([1])))
+            self.assertNotIn(numpy.ndarray, nt.native_types)
+            self.assertNotIn(numpy.ndarray, nt.native_logical_types)
+            self.assertNotIn(numpy.ndarray, nt.native_numeric_types)
+            self.assertNotIn(numpy.ndarray, nt.native_integer_types)
+            self.assertNotIn(numpy.ndarray, nt.native_complex_types)
+
+            self.assertTrue(nt.check_if_numeric_type(numpy.float64(1)))
+            self.assertIn(numpy.float64, nt.native_types)
+            self.assertNotIn(numpy.float64, nt.native_logical_types)
+            self.assertIn(numpy.float64, nt.native_numeric_types)
+            self.assertNotIn(numpy.float64, nt.native_integer_types)
+            self.assertNotIn(numpy.float64, nt.native_complex_types)
+
+            self.assertTrue(nt.check_if_numeric_type(numpy.int64(1)))
+            self.assertIn(numpy.int64, nt.native_types)
+            self.assertNotIn(numpy.int64, nt.native_logical_types)
+            self.assertIn(numpy.int64, nt.native_numeric_types)
+            self.assertIn(numpy.int64, nt.native_integer_types)
+            self.assertNotIn(numpy.int64, nt.native_complex_types)
+
+            self.assertFalse(nt.check_if_numeric_type(numpy.complex128(1)))
+            self.assertIn(numpy.complex128, nt.native_types)
+            self.assertNotIn(numpy.complex128, nt.native_logical_types)
+            self.assertNotIn(numpy.complex128, nt.native_numeric_types)
+            self.assertNotIn(numpy.complex128, nt.native_integer_types)
+            self.assertIn(numpy.complex128, nt.native_complex_types)
diff --git a/pyomo/common/tests/test_orderedset.py b/pyomo/common/tests/test_orderedset.py
index d87bebc1e4a..8f944e66bd7 100644
--- a/pyomo/common/tests/test_orderedset.py
+++ b/pyomo/common/tests/test_orderedset.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/tests/test_plugin.py b/pyomo/common/tests/test_plugin.py
index 86d136dd9d1..54431334d5b 100644
--- a/pyomo/common/tests/test_plugin.py
+++ b/pyomo/common/tests/test_plugin.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/tests/test_sorting.py b/pyomo/common/tests/test_sorting.py
index 7a9fe5ac923..7fbefda6a19 100644
--- a/pyomo/common/tests/test_sorting.py
+++ b/pyomo/common/tests/test_sorting.py
@@ -2,7 +2,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/tests/test_tee.py b/pyomo/common/tests/test_tee.py
index 666a431631f..a5c6ee894b2 100644
--- a/pyomo/common/tests/test_tee.py
+++ b/pyomo/common/tests/test_tee.py
@@ -2,7 +2,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/tests/test_tempfile.py b/pyomo/common/tests/test_tempfile.py
index 5e75c55305a..c49aa8c6771 100644
--- a/pyomo/common/tests/test_tempfile.py
+++ b/pyomo/common/tests/test_tempfile.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/tests/test_timing.py b/pyomo/common/tests/test_timing.py
index d885359e6c6..90f4cdcd034 100644
--- a/pyomo/common/tests/test_timing.py
+++ b/pyomo/common/tests/test_timing.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -35,7 +35,7 @@
     Any,
     TransformationFactory,
 )
-from pyomo.core.base.var import _VarData
+from pyomo.core.base.var import VarData
 
 
 class _pseudo_component(Var):
@@ -62,7 +62,7 @@ def test_raw_construction_timer(self):
         )
         v = Var()
         v.construct()
-        a = ConstructionTimer(_VarData(v))
+        a = ConstructionTimer(VarData(v))
         self.assertRegex(
             str(a),
             r"ConstructionTimer object for Var ScalarVar\[NOTSET\]; "
@@ -107,7 +107,6 @@ def test_report_timing(self):
                 m.y = Var(Any, dense=False)
                 xfrm.apply_to(m)
             result = out.getvalue().strip()
-            self.maxDiff = None
             for l, r in zip(result.splitlines(), ref.splitlines()):
                 self.assertRegex(str(l.strip()), str(r.strip()))
         finally:
@@ -122,7 +121,6 @@ def test_report_timing(self):
             m.y = Var(Any, dense=False)
             xfrm.apply_to(m)
             result = os.getvalue().strip()
-            self.maxDiff = None
             for l, r in zip(result.splitlines(), ref.splitlines()):
                 self.assertRegex(str(l.strip()), str(r.strip()))
         finally:
@@ -135,7 +133,6 @@ def test_report_timing(self):
             m.y = Var(Any, dense=False)
             xfrm.apply_to(m)
             result = os.getvalue().strip()
-            self.maxDiff = None
             for l, r in zip(result.splitlines(), ref.splitlines()):
                 self.assertRegex(str(l.strip()), str(r.strip()))
             self.assertEqual(buf.getvalue().strip(), "")
@@ -172,7 +169,6 @@ def test_report_timing_context_manager(self):
                     xfrm.apply_to(m)
                 self.assertEqual(OUT.getvalue(), "")
                 result = OS.getvalue().strip()
-                self.maxDiff = None
                 for l, r in zip_longest(result.splitlines(), ref.splitlines()):
                     self.assertRegex(str(l.strip()), str(r.strip()))
             # Active reporting is False: the previous log should not have changed
diff --git a/pyomo/common/tests/test_typing.py b/pyomo/common/tests/test_typing.py
index 982462f8a8d..e65effe7f29 100644
--- a/pyomo/common/tests/test_typing.py
+++ b/pyomo/common/tests/test_typing.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/tests/test_unittest.py b/pyomo/common/tests/test_unittest.py
index e3779e6f86e..9344853b737 100644
--- a/pyomo/common/tests/test_unittest.py
+++ b/pyomo/common/tests/test_unittest.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/timing.py b/pyomo/common/timing.py
index b37570fa666..d502b38d12d 100644
--- a/pyomo/common/timing.py
+++ b/pyomo/common/timing.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/common/unittest.py b/pyomo/common/unittest.py
index 1ed26f72320..c78e003a07d 100644
--- a/pyomo/common/unittest.py
+++ b/pyomo/common/unittest.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -498,6 +498,10 @@ class TestCase(_unittest.TestCase):
 
     __doc__ += _unittest.TestCase.__doc__
 
+    # By default, we always want to spend the time to create the full
+    # diff of the test reault and the baseline
+    maxDiff = None
+
     def assertStructuredAlmostEqual(
         self,
         first,
@@ -631,7 +635,7 @@ def initialize_dependencies(self):
         cls.package_modules = {}
         packages_used = set(sum(list(cls.package_dependencies.values()), []))
         for package_ in packages_used:
-            pack, pack_avail = attempt_import(package_, defer_check=False)
+            pack, pack_avail = attempt_import(package_, defer_import=False)
             cls.package_available[package_] = pack_avail
             cls.package_modules[package_] = pack
 
@@ -779,6 +783,7 @@ def filter_fcn(self, line):
         return False
 
     def filter_file_contents(self, lines, abstol=None):
+        _numpy_scalar_re = re.compile(r'np.(int|float)\d+\(([^\)]+)\)')
         filtered = []
         deprecated = None
         for line in lines:
@@ -803,6 +808,15 @@ def filter_file_contents(self, lines, abstol=None):
             item_list = []
             items = line.strip().split()
             for i in items:
+                # Split up lists, dicts, and sets
+                while i and i[0] in '[{':
+                    item_list.append(i[0])
+                    i = i[1:]
+                tail = []
+                while i and i[-1] in ',:]}':
+                    tail.append(i[-1])
+                    i = i[:-1]
+
                 # A few substitutions to get tests passing on pypy3
                 if ".inf" in i:
                     i = i.replace(".inf", "inf")
@@ -810,9 +824,19 @@ def filter_file_contents(self, lines, abstol=None):
                     i = i.replace("null", "None")
 
                 try:
-                    item_list.append(float(i))
+                    # Numpy 2.x changed the repr for scalars.  Convert
+                    # the new scalar reprs back to the original (which
+                    # were indistinguishable from python floats/ints)
+                    np_match = _numpy_scalar_re.match(i)
+                    if np_match:
+                        item_list.append(float(np_match.group(2)))
+                    else:
+                        item_list.append(float(i))
                 except:
                     item_list.append(i)
+                if tail:
+                    tail.reverse()
+                    item_list.extend(tail)
 
             # We can get printed results objects where the baseline is
             # exactly 0 (and omitted) and the test is slightly non-zero.
@@ -820,12 +844,13 @@ def filter_file_contents(self, lines, abstol=None):
             # results objects and remote them if they are within
             # tolerance of 0
             if (
-                len(item_list) == 2
-                and item_list[0] == 'Value:'
-                and type(item_list[1]) is float
-                and abs(item_list[1]) < (abstol or 0)
-                and len(filtered[-1]) == 1
-                and filtered[-1][0][-1] == ':'
+                len(item_list) == 3
+                and item_list[0] == 'Value'
+                and item_list[1] == ':'
+                and type(item_list[2]) is float
+                and abs(item_list[2]) < (abstol or 0)
+                and len(filtered[-1]) == 2
+                and filtered[-1][1] == ':'
             ):
                 filtered.pop()
             else:
diff --git a/pyomo/contrib/__init__.py b/pyomo/contrib/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/__init__.py
+++ b/pyomo/contrib/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/ampl_function_demo/__init__.py b/pyomo/contrib/ampl_function_demo/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/ampl_function_demo/__init__.py
+++ b/pyomo/contrib/ampl_function_demo/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/ampl_function_demo/build.py b/pyomo/contrib/ampl_function_demo/build.py
index cd35064ea4e..764a613b3d7 100644
--- a/pyomo/contrib/ampl_function_demo/build.py
+++ b/pyomo/contrib/ampl_function_demo/build.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/ampl_function_demo/plugins.py b/pyomo/contrib/ampl_function_demo/plugins.py
index 230d9c4b667..5a200174c43 100644
--- a/pyomo/contrib/ampl_function_demo/plugins.py
+++ b/pyomo/contrib/ampl_function_demo/plugins.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/ampl_function_demo/src/CMakeLists.txt b/pyomo/contrib/ampl_function_demo/src/CMakeLists.txt
index ce2c1a60f82..67efc13d3c8 100644
--- a/pyomo/contrib/ampl_function_demo/src/CMakeLists.txt
+++ b/pyomo/contrib/ampl_function_demo/src/CMakeLists.txt
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/ampl_function_demo/src/FindASL.cmake b/pyomo/contrib/ampl_function_demo/src/FindASL.cmake
index f413176f1cc..8bbc048fa6e 100644
--- a/pyomo/contrib/ampl_function_demo/src/FindASL.cmake
+++ b/pyomo/contrib/ampl_function_demo/src/FindASL.cmake
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/ampl_function_demo/src/functions.c b/pyomo/contrib/ampl_function_demo/src/functions.c
index f62148c995a..e87af745aea 100644
--- a/pyomo/contrib/ampl_function_demo/src/functions.c
+++ b/pyomo/contrib/ampl_function_demo/src/functions.c
@@ -1,6 +1,6 @@
 /* ___________________________________________________________________________
  * Pyomo: Python Optimization Modeling Objects
- * Copyright (c) 2008-2022
+ * Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
  * Under the terms of Contract DE-NA0003525 with National Technology and
  * Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/ampl_function_demo/tests/__init__.py b/pyomo/contrib/ampl_function_demo/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/ampl_function_demo/tests/__init__.py
+++ b/pyomo/contrib/ampl_function_demo/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/ampl_function_demo/tests/test_ampl_function_demo.py b/pyomo/contrib/ampl_function_demo/tests/test_ampl_function_demo.py
index af52c2def9f..39890494d55 100644
--- a/pyomo/contrib/ampl_function_demo/tests/test_ampl_function_demo.py
+++ b/pyomo/contrib/ampl_function_demo/tests/test_ampl_function_demo.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/appsi/__init__.py b/pyomo/contrib/appsi/__init__.py
index df3ba212448..2f06fc89e70 100644
--- a/pyomo/contrib/appsi/__init__.py
+++ b/pyomo/contrib/appsi/__init__.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from . import base
 from . import solvers
 from . import writers
diff --git a/pyomo/contrib/appsi/base.py b/pyomo/contrib/appsi/base.py
index e6186eeedd2..6d2b5ccfcd4 100644
--- a/pyomo/contrib/appsi/base.py
+++ b/pyomo/contrib/appsi/base.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import abc
 import enum
 from typing import (
@@ -10,12 +21,12 @@
     Tuple,
     MutableMapping,
 )
-from pyomo.core.base.constraint import _GeneralConstraintData, Constraint
-from pyomo.core.base.sos import _SOSConstraintData, SOSConstraint
-from pyomo.core.base.var import _GeneralVarData, Var
-from pyomo.core.base.param import _ParamData, Param
-from pyomo.core.base.block import _BlockData, Block
-from pyomo.core.base.objective import _GeneralObjectiveData
+from pyomo.core.base.constraint import ConstraintData, Constraint
+from pyomo.core.base.sos import SOSConstraintData, SOSConstraint
+from pyomo.core.base.var import VarData, Var
+from pyomo.core.base.param import ParamData, Param
+from pyomo.core.base.block import BlockData, Block
+from pyomo.core.base.objective import ObjectiveData
 from pyomo.common.collections import ComponentMap
 from .utils.get_objective import get_objective
 from .utils.collect_vars_and_named_exprs import collect_vars_and_named_exprs
@@ -168,9 +179,7 @@ def __init__(
 
 
 class SolutionLoaderBase(abc.ABC):
-    def load_vars(
-        self, vars_to_load: Optional[Sequence[_GeneralVarData]] = None
-    ) -> NoReturn:
+    def load_vars(self, vars_to_load: Optional[Sequence[VarData]] = None) -> NoReturn:
         """
         Load the solution of the primal variables into the value attribute of the variables.
 
@@ -186,8 +195,8 @@ def load_vars(
 
     @abc.abstractmethod
     def get_primals(
-        self, vars_to_load: Optional[Sequence[_GeneralVarData]] = None
-    ) -> Mapping[_GeneralVarData, float]:
+        self, vars_to_load: Optional[Sequence[VarData]] = None
+    ) -> Mapping[VarData, float]:
         """
         Returns a ComponentMap mapping variable to var value.
 
@@ -205,8 +214,8 @@ def get_primals(
         pass
 
     def get_duals(
-        self, cons_to_load: Optional[Sequence[_GeneralConstraintData]] = None
-    ) -> Dict[_GeneralConstraintData, float]:
+        self, cons_to_load: Optional[Sequence[ConstraintData]] = None
+    ) -> Dict[ConstraintData, float]:
         """
         Returns a dictionary mapping constraint to dual value.
 
@@ -224,8 +233,8 @@ def get_duals(
         raise NotImplementedError(f'{type(self)} does not support the get_duals method')
 
     def get_slacks(
-        self, cons_to_load: Optional[Sequence[_GeneralConstraintData]] = None
-    ) -> Dict[_GeneralConstraintData, float]:
+        self, cons_to_load: Optional[Sequence[ConstraintData]] = None
+    ) -> Dict[ConstraintData, float]:
         """
         Returns a dictionary mapping constraint to slack.
 
@@ -245,8 +254,8 @@ def get_slacks(
         )
 
     def get_reduced_costs(
-        self, vars_to_load: Optional[Sequence[_GeneralVarData]] = None
-    ) -> Mapping[_GeneralVarData, float]:
+        self, vars_to_load: Optional[Sequence[VarData]] = None
+    ) -> Mapping[VarData, float]:
         """
         Returns a ComponentMap mapping variable to reduced cost.
 
@@ -292,8 +301,8 @@ def __init__(
         self._reduced_costs = reduced_costs
 
     def get_primals(
-        self, vars_to_load: Optional[Sequence[_GeneralVarData]] = None
-    ) -> Mapping[_GeneralVarData, float]:
+        self, vars_to_load: Optional[Sequence[VarData]] = None
+    ) -> Mapping[VarData, float]:
         if self._primals is None:
             raise RuntimeError(
                 'Solution loader does not currently have a valid solution. Please '
@@ -308,8 +317,8 @@ def get_primals(
             return primals
 
     def get_duals(
-        self, cons_to_load: Optional[Sequence[_GeneralConstraintData]] = None
-    ) -> Dict[_GeneralConstraintData, float]:
+        self, cons_to_load: Optional[Sequence[ConstraintData]] = None
+    ) -> Dict[ConstraintData, float]:
         if self._duals is None:
             raise RuntimeError(
                 'Solution loader does not currently have valid duals. Please '
@@ -325,8 +334,8 @@ def get_duals(
         return duals
 
     def get_slacks(
-        self, cons_to_load: Optional[Sequence[_GeneralConstraintData]] = None
-    ) -> Dict[_GeneralConstraintData, float]:
+        self, cons_to_load: Optional[Sequence[ConstraintData]] = None
+    ) -> Dict[ConstraintData, float]:
         if self._slacks is None:
             raise RuntimeError(
                 'Solution loader does not currently have valid slacks. Please '
@@ -342,8 +351,8 @@ def get_slacks(
         return slacks
 
     def get_reduced_costs(
-        self, vars_to_load: Optional[Sequence[_GeneralVarData]] = None
-    ) -> Mapping[_GeneralVarData, float]:
+        self, vars_to_load: Optional[Sequence[VarData]] = None
+    ) -> Mapping[VarData, float]:
         if self._reduced_costs is None:
             raise RuntimeError(
                 'Solution loader does not currently have valid reduced costs. Please '
@@ -610,13 +619,13 @@ def __str__(self):
             return self.name
 
     @abc.abstractmethod
-    def solve(self, model: _BlockData, timer: HierarchicalTimer = None) -> Results:
+    def solve(self, model: BlockData, timer: HierarchicalTimer = None) -> Results:
         """
         Solve a Pyomo model.
 
         Parameters
         ----------
-        model: _BlockData
+        model: BlockData
             The Pyomo model to be solved
         timer: HierarchicalTimer
             An option timer for reporting timing
@@ -697,9 +706,7 @@ class PersistentSolver(Solver):
     def is_persistent(self):
         return True
 
-    def load_vars(
-        self, vars_to_load: Optional[Sequence[_GeneralVarData]] = None
-    ) -> NoReturn:
+    def load_vars(self, vars_to_load: Optional[Sequence[VarData]] = None) -> NoReturn:
         """
         Load the solution of the primal variables into the value attribute of the variables.
 
@@ -715,13 +722,13 @@ def load_vars(
 
     @abc.abstractmethod
     def get_primals(
-        self, vars_to_load: Optional[Sequence[_GeneralVarData]] = None
-    ) -> Mapping[_GeneralVarData, float]:
+        self, vars_to_load: Optional[Sequence[VarData]] = None
+    ) -> Mapping[VarData, float]:
         pass
 
     def get_duals(
-        self, cons_to_load: Optional[Sequence[_GeneralConstraintData]] = None
-    ) -> Dict[_GeneralConstraintData, float]:
+        self, cons_to_load: Optional[Sequence[ConstraintData]] = None
+    ) -> Dict[ConstraintData, float]:
         """
         Declare sign convention in docstring here.
 
@@ -741,8 +748,8 @@ def get_duals(
         )
 
     def get_slacks(
-        self, cons_to_load: Optional[Sequence[_GeneralConstraintData]] = None
-    ) -> Dict[_GeneralConstraintData, float]:
+        self, cons_to_load: Optional[Sequence[ConstraintData]] = None
+    ) -> Dict[ConstraintData, float]:
         """
         Parameters
         ----------
@@ -760,8 +767,8 @@ def get_slacks(
         )
 
     def get_reduced_costs(
-        self, vars_to_load: Optional[Sequence[_GeneralVarData]] = None
-    ) -> Mapping[_GeneralVarData, float]:
+        self, vars_to_load: Optional[Sequence[VarData]] = None
+    ) -> Mapping[VarData, float]:
         """
         Parameters
         ----------
@@ -788,43 +795,43 @@ def set_instance(self, model):
         pass
 
     @abc.abstractmethod
-    def add_variables(self, variables: List[_GeneralVarData]):
+    def add_variables(self, variables: List[VarData]):
         pass
 
     @abc.abstractmethod
-    def add_params(self, params: List[_ParamData]):
+    def add_params(self, params: List[ParamData]):
         pass
 
     @abc.abstractmethod
-    def add_constraints(self, cons: List[_GeneralConstraintData]):
+    def add_constraints(self, cons: List[ConstraintData]):
         pass
 
     @abc.abstractmethod
-    def add_block(self, block: _BlockData):
+    def add_block(self, block: BlockData):
         pass
 
     @abc.abstractmethod
-    def remove_variables(self, variables: List[_GeneralVarData]):
+    def remove_variables(self, variables: List[VarData]):
         pass
 
     @abc.abstractmethod
-    def remove_params(self, params: List[_ParamData]):
+    def remove_params(self, params: List[ParamData]):
         pass
 
     @abc.abstractmethod
-    def remove_constraints(self, cons: List[_GeneralConstraintData]):
+    def remove_constraints(self, cons: List[ConstraintData]):
         pass
 
     @abc.abstractmethod
-    def remove_block(self, block: _BlockData):
+    def remove_block(self, block: BlockData):
         pass
 
     @abc.abstractmethod
-    def set_objective(self, obj: _GeneralObjectiveData):
+    def set_objective(self, obj: ObjectiveData):
         pass
 
     @abc.abstractmethod
-    def update_variables(self, variables: List[_GeneralVarData]):
+    def update_variables(self, variables: List[VarData]):
         pass
 
     @abc.abstractmethod
@@ -846,20 +853,20 @@ def get_primals(self, vars_to_load=None):
         return self._solver.get_primals(vars_to_load=vars_to_load)
 
     def get_duals(
-        self, cons_to_load: Optional[Sequence[_GeneralConstraintData]] = None
-    ) -> Dict[_GeneralConstraintData, float]:
+        self, cons_to_load: Optional[Sequence[ConstraintData]] = None
+    ) -> Dict[ConstraintData, float]:
         self._assert_solution_still_valid()
         return self._solver.get_duals(cons_to_load=cons_to_load)
 
     def get_slacks(
-        self, cons_to_load: Optional[Sequence[_GeneralConstraintData]] = None
-    ) -> Dict[_GeneralConstraintData, float]:
+        self, cons_to_load: Optional[Sequence[ConstraintData]] = None
+    ) -> Dict[ConstraintData, float]:
         self._assert_solution_still_valid()
         return self._solver.get_slacks(cons_to_load=cons_to_load)
 
     def get_reduced_costs(
-        self, vars_to_load: Optional[Sequence[_GeneralVarData]] = None
-    ) -> Mapping[_GeneralVarData, float]:
+        self, vars_to_load: Optional[Sequence[VarData]] = None
+    ) -> Mapping[VarData, float]:
         self._assert_solution_still_valid()
         return self._solver.get_reduced_costs(vars_to_load=vars_to_load)
 
@@ -943,10 +950,10 @@ def set_instance(self, model):
             self.set_objective(None)
 
     @abc.abstractmethod
-    def _add_variables(self, variables: List[_GeneralVarData]):
+    def _add_variables(self, variables: List[VarData]):
         pass
 
-    def add_variables(self, variables: List[_GeneralVarData]):
+    def add_variables(self, variables: List[VarData]):
         for v in variables:
             if id(v) in self._referenced_variables:
                 raise ValueError(
@@ -964,19 +971,19 @@ def add_variables(self, variables: List[_GeneralVarData]):
         self._add_variables(variables)
 
     @abc.abstractmethod
-    def _add_params(self, params: List[_ParamData]):
+    def _add_params(self, params: List[ParamData]):
         pass
 
-    def add_params(self, params: List[_ParamData]):
+    def add_params(self, params: List[ParamData]):
         for p in params:
             self._params[id(p)] = p
         self._add_params(params)
 
     @abc.abstractmethod
-    def _add_constraints(self, cons: List[_GeneralConstraintData]):
+    def _add_constraints(self, cons: List[ConstraintData]):
         pass
 
-    def _check_for_new_vars(self, variables: List[_GeneralVarData]):
+    def _check_for_new_vars(self, variables: List[VarData]):
         new_vars = dict()
         for v in variables:
             v_id = id(v)
@@ -984,7 +991,7 @@ def _check_for_new_vars(self, variables: List[_GeneralVarData]):
                 new_vars[v_id] = v
         self.add_variables(list(new_vars.values()))
 
-    def _check_to_remove_vars(self, variables: List[_GeneralVarData]):
+    def _check_to_remove_vars(self, variables: List[VarData]):
         vars_to_remove = dict()
         for v in variables:
             v_id = id(v)
@@ -993,7 +1000,7 @@ def _check_to_remove_vars(self, variables: List[_GeneralVarData]):
                 vars_to_remove[v_id] = v
         self.remove_variables(list(vars_to_remove.values()))
 
-    def add_constraints(self, cons: List[_GeneralConstraintData]):
+    def add_constraints(self, cons: List[ConstraintData]):
         all_fixed_vars = dict()
         for con in cons:
             if con in self._named_expressions:
@@ -1023,10 +1030,10 @@ def add_constraints(self, cons: List[_GeneralConstraintData]):
             v.fix()
 
     @abc.abstractmethod
-    def _add_sos_constraints(self, cons: List[_SOSConstraintData]):
+    def _add_sos_constraints(self, cons: List[SOSConstraintData]):
         pass
 
-    def add_sos_constraints(self, cons: List[_SOSConstraintData]):
+    def add_sos_constraints(self, cons: List[SOSConstraintData]):
         for con in cons:
             if con in self._vars_referenced_by_con:
                 raise ValueError(
@@ -1043,10 +1050,10 @@ def add_sos_constraints(self, cons: List[_SOSConstraintData]):
         self._add_sos_constraints(cons)
 
     @abc.abstractmethod
-    def _set_objective(self, obj: _GeneralObjectiveData):
+    def _set_objective(self, obj: ObjectiveData):
         pass
 
-    def set_objective(self, obj: _GeneralObjectiveData):
+    def set_objective(self, obj: ObjectiveData):
         if self._objective is not None:
             for v in self._vars_referenced_by_obj:
                 self._referenced_variables[id(v)][2] = None
@@ -1121,10 +1128,10 @@ def add_block(self, block):
             self.set_objective(obj)
 
     @abc.abstractmethod
-    def _remove_constraints(self, cons: List[_GeneralConstraintData]):
+    def _remove_constraints(self, cons: List[ConstraintData]):
         pass
 
-    def remove_constraints(self, cons: List[_GeneralConstraintData]):
+    def remove_constraints(self, cons: List[ConstraintData]):
         self._remove_constraints(cons)
         for con in cons:
             if con not in self._named_expressions:
@@ -1143,10 +1150,10 @@ def remove_constraints(self, cons: List[_GeneralConstraintData]):
             del self._vars_referenced_by_con[con]
 
     @abc.abstractmethod
-    def _remove_sos_constraints(self, cons: List[_SOSConstraintData]):
+    def _remove_sos_constraints(self, cons: List[SOSConstraintData]):
         pass
 
-    def remove_sos_constraints(self, cons: List[_SOSConstraintData]):
+    def remove_sos_constraints(self, cons: List[SOSConstraintData]):
         self._remove_sos_constraints(cons)
         for con in cons:
             if con not in self._vars_referenced_by_con:
@@ -1163,10 +1170,10 @@ def remove_sos_constraints(self, cons: List[_SOSConstraintData]):
             del self._vars_referenced_by_con[con]
 
     @abc.abstractmethod
-    def _remove_variables(self, variables: List[_GeneralVarData]):
+    def _remove_variables(self, variables: List[VarData]):
         pass
 
-    def remove_variables(self, variables: List[_GeneralVarData]):
+    def remove_variables(self, variables: List[VarData]):
         self._remove_variables(variables)
         for v in variables:
             v_id = id(v)
@@ -1187,10 +1194,10 @@ def remove_variables(self, variables: List[_GeneralVarData]):
             del self._vars[v_id]
 
     @abc.abstractmethod
-    def _remove_params(self, params: List[_ParamData]):
+    def _remove_params(self, params: List[ParamData]):
         pass
 
-    def remove_params(self, params: List[_ParamData]):
+    def remove_params(self, params: List[ParamData]):
         self._remove_params(params)
         for p in params:
             del self._params[id(p)]
@@ -1235,10 +1242,10 @@ def remove_block(self, block):
         )
 
     @abc.abstractmethod
-    def _update_variables(self, variables: List[_GeneralVarData]):
+    def _update_variables(self, variables: List[VarData]):
         pass
 
-    def update_variables(self, variables: List[_GeneralVarData]):
+    def update_variables(self, variables: List[VarData]):
         for v in variables:
             self._vars[id(v)] = (
                 v,
@@ -1323,12 +1330,12 @@ def update(self, timer: HierarchicalTimer = None):
             for c in self._vars_referenced_by_con.keys():
                 if c not in current_cons_dict and c not in current_sos_dict:
                     if (c.ctype is Constraint) or (
-                        c.ctype is None and isinstance(c, _GeneralConstraintData)
+                        c.ctype is None and isinstance(c, ConstraintData)
                     ):
                         old_cons.append(c)
                     else:
                         assert (c.ctype is SOSConstraint) or (
-                            c.ctype is None and isinstance(c, _SOSConstraintData)
+                            c.ctype is None and isinstance(c, SOSConstraintData)
                         )
                         old_sos.append(c)
         self.remove_constraints(old_cons)
@@ -1518,7 +1525,7 @@ def update(self, timer: HierarchicalTimer = None):
 class LegacySolverInterface(object):
     def solve(
         self,
-        model: _BlockData,
+        model: BlockData,
         tee: bool = False,
         load_solutions: bool = True,
         logfile: Optional[str] = None,
@@ -1654,7 +1661,7 @@ def license_is_valid(self) -> bool:
 
     @property
     def options(self):
-        for solver_name in ['gurobi', 'ipopt', 'cplex', 'cbc', 'highs']:
+        for solver_name in ['gurobi', 'ipopt', 'cplex', 'cbc', 'highs', 'maingo']:
             if hasattr(self, solver_name + '_options'):
                 return getattr(self, solver_name + '_options')
         raise NotImplementedError('Could not find the correct options')
@@ -1662,7 +1669,7 @@ def options(self):
     @options.setter
     def options(self, val):
         found = False
-        for solver_name in ['gurobi', 'ipopt', 'cplex', 'cbc', 'highs']:
+        for solver_name in ['gurobi', 'ipopt', 'cplex', 'cbc', 'highs', 'maingo']:
             if hasattr(self, solver_name + '_options'):
                 setattr(self, solver_name + '_options', val)
                 found = True
@@ -1685,7 +1692,7 @@ def decorator(cls):
             class LegacySolver(LegacySolverInterface, cls):
                 pass
 
-            LegacySolverFactory.register(name, doc)(LegacySolver)
+            LegacySolverFactory.register('appsi_' + name, doc)(LegacySolver)
 
             return cls
 
diff --git a/pyomo/contrib/appsi/build.py b/pyomo/contrib/appsi/build.py
index 2c8d02dd3ac..38f8cb713ca 100644
--- a/pyomo/contrib/appsi/build.py
+++ b/pyomo/contrib/appsi/build.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -16,15 +16,6 @@
 import tempfile
 
 
-def handleReadonly(function, path, excinfo):
-    excvalue = excinfo[1]
-    if excvalue.errno == errno.EACCES:
-        os.chmod(path, stat.S_IRWXU | stat.S_IRWXG | stat.S_IRWXO)  # 0777
-        function(path)
-    else:
-        raise
-
-
 def get_appsi_extension(in_setup=False, appsi_root=None):
     from pybind11.setup_helpers import Pybind11Extension
 
@@ -66,6 +57,7 @@ def build_appsi(args=[]):
     from setuptools import Distribution
     from pybind11.setup_helpers import build_ext
     import pybind11.setup_helpers
+    from pyomo.common.cmake_builder import handleReadonly
     from pyomo.common.envvar import PYOMO_CONFIG_DIR
     from pyomo.common.fileutils import this_file_dir
 
diff --git a/pyomo/contrib/appsi/cmodel/__init__.py b/pyomo/contrib/appsi/cmodel/__init__.py
index 9c276b518de..cc2aec28241 100644
--- a/pyomo/contrib/appsi/cmodel/__init__.py
+++ b/pyomo/contrib/appsi/cmodel/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/appsi/cmodel/src/cmodel_bindings.cpp b/pyomo/contrib/appsi/cmodel/src/cmodel_bindings.cpp
index db9d3112069..5a838ffd786 100644
--- a/pyomo/contrib/appsi/cmodel/src/cmodel_bindings.cpp
+++ b/pyomo/contrib/appsi/cmodel/src/cmodel_bindings.cpp
@@ -1,7 +1,7 @@
 /**___________________________________________________________________________
  *
  *  Pyomo: Python Optimization Modeling Objects
- * Copyright (c) 2008-2022
+ * Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
  * Under the terms of Contract DE-NA0003525 with National Technology and
  * Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -63,7 +63,8 @@ PYBIND11_MODULE(appsi_cmodel, m) {
   m.def("appsi_exprs_from_pyomo_exprs", &appsi_exprs_from_pyomo_exprs);
   m.def("appsi_expr_from_pyomo_expr", &appsi_expr_from_pyomo_expr);
   m.def("prep_for_repn", &prep_for_repn);
-  py::class_<PyomoExprTypes>(m, "PyomoExprTypes").def(py::init<>());
+  py::class_<PyomoExprTypes>(m, "PyomoExprTypes", py::module_local())
+      .def(py::init<>());
   py::class_<Node, std::shared_ptr<Node>>(m, "Node")
       .def("is_variable_type", &Node::is_variable_type)
       .def("is_param_type", &Node::is_param_type)
@@ -165,7 +166,7 @@ PYBIND11_MODULE(appsi_cmodel, m) {
       .def(py::init<>())
       .def("write", &LPWriter::write)
       .def("get_solve_cons", &LPWriter::get_solve_cons);
-  py::enum_<ExprType>(m, "ExprType")
+  py::enum_<ExprType>(m, "ExprType", py::module_local())
       .value("py_float", ExprType::py_float)
       .value("var", ExprType::var)
       .value("param", ExprType::param)
diff --git a/pyomo/contrib/appsi/cmodel/src/common.cpp b/pyomo/contrib/appsi/cmodel/src/common.cpp
index 255a0a3a70f..6f8002cb50e 100644
--- a/pyomo/contrib/appsi/cmodel/src/common.cpp
+++ b/pyomo/contrib/appsi/cmodel/src/common.cpp
@@ -1,3 +1,15 @@
+/**___________________________________________________________________________
+ *
+ * Pyomo: Python Optimization Modeling Objects
+ * Copyright (c) 2008-2024
+ * National Technology and Engineering Solutions of Sandia, LLC
+ * Under the terms of Contract DE-NA0003525 with National Technology and
+ * Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+ * rights in this software.
+ * This software is distributed under the 3-clause BSD License.
+ * ___________________________________________________________________________
+**/
+
 #include "common.hpp"
 
 double inf;
diff --git a/pyomo/contrib/appsi/cmodel/src/common.hpp b/pyomo/contrib/appsi/cmodel/src/common.hpp
index 36afd549116..9edc9571a4d 100644
--- a/pyomo/contrib/appsi/cmodel/src/common.hpp
+++ b/pyomo/contrib/appsi/cmodel/src/common.hpp
@@ -1,3 +1,15 @@
+/**___________________________________________________________________________
+ *
+ * Pyomo: Python Optimization Modeling Objects
+ * Copyright (c) 2008-2024
+ * National Technology and Engineering Solutions of Sandia, LLC
+ * Under the terms of Contract DE-NA0003525 with National Technology and
+ * Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+ * rights in this software.
+ * This software is distributed under the 3-clause BSD License.
+ * ___________________________________________________________________________
+**/
+
 #include <pybind11/pybind11.h>
 #include <pybind11/stl.h>
 
diff --git a/pyomo/contrib/appsi/cmodel/src/expression.cpp b/pyomo/contrib/appsi/cmodel/src/expression.cpp
index 1923d3a1894..a49d6f2e499 100644
--- a/pyomo/contrib/appsi/cmodel/src/expression.cpp
+++ b/pyomo/contrib/appsi/cmodel/src/expression.cpp
@@ -1,1970 +1,1986 @@
-#include "expression.hpp"
-
-bool Leaf::is_leaf() { return true; }
-
-bool Var::is_variable_type() { return true; }
-
-bool Param::is_param_type() { return true; }
-
-bool Constant::is_constant_type() { return true; }
-
-bool Expression::is_expression_type() { return true; }
-
-double Leaf::evaluate() { return value; }
-
-double Var::get_lb() {
-  if (fixed)
-    return value;
-  else
-    return std::max(lb->evaluate(), domain_lb);
-}
-
-double Var::get_ub() {
-  if (fixed)
-    return value;
-  else
-    return std::min(ub->evaluate(), domain_ub);
-}
-
-Domain Var::get_domain() { return domain; }
-
-bool Operator::is_operator_type() { return true; }
-
-std::vector<std::shared_ptr<Operator>> Expression::get_operators() {
-  std::vector<std::shared_ptr<Operator>> res(n_operators);
-  for (unsigned int i = 0; i < n_operators; ++i) {
-    res[i] = operators[i];
-  }
-  return res;
-}
-
-double Leaf::get_value_from_array(double *val_array) { return value; }
-
-double Expression::get_value_from_array(double *val_array) {
-  return val_array[n_operators - 1];
-}
-
-double Operator::get_value_from_array(double *val_array) {
-  return val_array[index];
-}
-
-void MultiplyOperator::evaluate(double *values) {
-  values[index] = operand1->get_value_from_array(values) *
-                  operand2->get_value_from_array(values);
-}
-
-void ExternalOperator::evaluate(double *values) {
-  // It would be nice to implement this, but it will take some more work.
-  // This would require dynamic linking to the external function.
-  throw std::runtime_error("cannot evaluate ExternalOperator yet");
-}
-
-void LinearOperator::evaluate(double *values) {
-  values[index] = constant->evaluate();
-  for (unsigned int i = 0; i < nterms; ++i) {
-    values[index] += coefficients[i]->evaluate() * variables[i]->evaluate();
-  }
-}
-
-void SumOperator::evaluate(double *values) {
-  values[index] = 0.0;
-  for (unsigned int i = 0; i < nargs; ++i) {
-    values[index] += operands[i]->get_value_from_array(values);
-  }
-}
-
-void DivideOperator::evaluate(double *values) {
-  values[index] = operand1->get_value_from_array(values) /
-                  operand2->get_value_from_array(values);
-}
-
-void PowerOperator::evaluate(double *values) {
-  values[index] = std::pow(operand1->get_value_from_array(values),
-                           operand2->get_value_from_array(values));
-}
-
-void NegationOperator::evaluate(double *values) {
-  values[index] = -operand->get_value_from_array(values);
-}
-
-void ExpOperator::evaluate(double *values) {
-  values[index] = std::exp(operand->get_value_from_array(values));
-}
-
-void LogOperator::evaluate(double *values) {
-  values[index] = std::log(operand->get_value_from_array(values));
-}
-
-void AbsOperator::evaluate(double *values) {
-  values[index] = std::fabs(operand->get_value_from_array(values));
-}
-
-void SqrtOperator::evaluate(double *values) {
-  values[index] = std::pow(operand->get_value_from_array(values), 0.5);
-}
-
-void Log10Operator::evaluate(double *values) {
-  values[index] = std::log10(operand->get_value_from_array(values));
-}
-
-void SinOperator::evaluate(double *values) {
-  values[index] = std::sin(operand->get_value_from_array(values));
-}
-
-void CosOperator::evaluate(double *values) {
-  values[index] = std::cos(operand->get_value_from_array(values));
-}
-
-void TanOperator::evaluate(double *values) {
-  values[index] = std::tan(operand->get_value_from_array(values));
-}
-
-void AsinOperator::evaluate(double *values) {
-  values[index] = std::asin(operand->get_value_from_array(values));
-}
-
-void AcosOperator::evaluate(double *values) {
-  values[index] = std::acos(operand->get_value_from_array(values));
-}
-
-void AtanOperator::evaluate(double *values) {
-  values[index] = std::atan(operand->get_value_from_array(values));
-}
-
-double Expression::evaluate() {
-  double *values = new double[n_operators];
-  for (unsigned int i = 0; i < n_operators; ++i) {
-    operators[i]->index = i;
-    operators[i]->evaluate(values);
-  }
-  double res = get_value_from_array(values);
-  delete[] values;
-  return res;
-}
-
-void UnaryOperator::identify_variables(
-    std::set<std::shared_ptr<Node>> &var_set,
-    std::shared_ptr<std::vector<std::shared_ptr<Var>>> var_vec) {
-  if (operand->is_variable_type()) {
-    if (var_set.count(operand) == 0) {
-      var_vec->push_back(std::dynamic_pointer_cast<Var>(operand));
-      var_set.insert(operand);
-    }
-  }
-}
-
-void BinaryOperator::identify_variables(
-    std::set<std::shared_ptr<Node>> &var_set,
-    std::shared_ptr<std::vector<std::shared_ptr<Var>>> var_vec) {
-  if (operand1->is_variable_type()) {
-    if (var_set.count(operand1) == 0) {
-      var_vec->push_back(std::dynamic_pointer_cast<Var>(operand1));
-      var_set.insert(operand1);
-    }
-  }
-  if (operand2->is_variable_type()) {
-    if (var_set.count(operand2) == 0) {
-      var_vec->push_back(std::dynamic_pointer_cast<Var>(operand2));
-      var_set.insert(operand2);
-    }
-  }
-}
-
-void ExternalOperator::identify_variables(
-    std::set<std::shared_ptr<Node>> &var_set,
-    std::shared_ptr<std::vector<std::shared_ptr<Var>>> var_vec) {
-  for (unsigned int i = 0; i < nargs; ++i) {
-    if (operands[i]->is_variable_type()) {
-      if (var_set.count(operands[i]) == 0) {
-        var_vec->push_back(std::dynamic_pointer_cast<Var>(operands[i]));
-        var_set.insert(operands[i]);
-      }
-    }
-  }
-}
-
-void LinearOperator::identify_variables(
-    std::set<std::shared_ptr<Node>> &var_set,
-    std::shared_ptr<std::vector<std::shared_ptr<Var>>> var_vec) {
-  for (unsigned int i = 0; i < nterms; ++i) {
-    if (var_set.count(variables[i]) == 0) {
-      var_vec->push_back(std::dynamic_pointer_cast<Var>(variables[i]));
-      var_set.insert(variables[i]);
-    }
-  }
-}
-
-void SumOperator::identify_variables(
-    std::set<std::shared_ptr<Node>> &var_set,
-    std::shared_ptr<std::vector<std::shared_ptr<Var>>> var_vec) {
-  for (unsigned int i = 0; i < nargs; ++i) {
-    if (operands[i]->is_variable_type()) {
-      if (var_set.count(operands[i]) == 0) {
-        var_vec->push_back(std::dynamic_pointer_cast<Var>(operands[i]));
-        var_set.insert(operands[i]);
-      }
-    }
-  }
-}
-
-std::shared_ptr<std::vector<std::shared_ptr<Var>>>
-Expression::identify_variables() {
-  std::set<std::shared_ptr<Node>> var_set;
-  std::shared_ptr<std::vector<std::shared_ptr<Var>>> res =
-      std::make_shared<std::vector<std::shared_ptr<Var>>>(var_set.size());
-  for (unsigned int i = 0; i < n_operators; ++i) {
-    operators[i]->identify_variables(var_set, res);
-  }
-  return res;
-}
-
-std::shared_ptr<std::vector<std::shared_ptr<Var>>> Var::identify_variables() {
-  std::shared_ptr<std::vector<std::shared_ptr<Var>>> res =
-      std::make_shared<std::vector<std::shared_ptr<Var>>>();
-  res->push_back(shared_from_this());
-  return res;
-}
-
-std::shared_ptr<std::vector<std::shared_ptr<Var>>>
-Constant::identify_variables() {
-  std::shared_ptr<std::vector<std::shared_ptr<Var>>> res =
-      std::make_shared<std::vector<std::shared_ptr<Var>>>();
-  return res;
-}
-
-std::shared_ptr<std::vector<std::shared_ptr<Var>>> Param::identify_variables() {
-  std::shared_ptr<std::vector<std::shared_ptr<Var>>> res =
-      std::make_shared<std::vector<std::shared_ptr<Var>>>();
-  return res;
-}
-
-std::shared_ptr<std::vector<std::shared_ptr<ExternalOperator>>>
-Expression::identify_external_operators() {
-  std::set<std::shared_ptr<Node>> external_set;
-  for (unsigned int i = 0; i < n_operators; ++i) {
-    if (operators[i]->is_external_operator()) {
-      external_set.insert(operators[i]);
-    }
-  }
-  std::shared_ptr<std::vector<std::shared_ptr<ExternalOperator>>> res =
-      std::make_shared<std::vector<std::shared_ptr<ExternalOperator>>>(
-          external_set.size());
-  int ndx = 0;
-  for (std::shared_ptr<Node> n : external_set) {
-    (*res)[ndx] = std::dynamic_pointer_cast<ExternalOperator>(n);
-    ndx += 1;
-  }
-  return res;
-}
-
-std::shared_ptr<std::vector<std::shared_ptr<ExternalOperator>>>
-Var::identify_external_operators() {
-  std::shared_ptr<std::vector<std::shared_ptr<ExternalOperator>>> res =
-      std::make_shared<std::vector<std::shared_ptr<ExternalOperator>>>();
-  return res;
-}
-
-std::shared_ptr<std::vector<std::shared_ptr<ExternalOperator>>>
-Constant::identify_external_operators() {
-  std::shared_ptr<std::vector<std::shared_ptr<ExternalOperator>>> res =
-      std::make_shared<std::vector<std::shared_ptr<ExternalOperator>>>();
-  return res;
-}
-
-std::shared_ptr<std::vector<std::shared_ptr<ExternalOperator>>>
-Param::identify_external_operators() {
-  std::shared_ptr<std::vector<std::shared_ptr<ExternalOperator>>> res =
-      std::make_shared<std::vector<std::shared_ptr<ExternalOperator>>>();
-  return res;
-}
-
-int Var::get_degree_from_array(int *degree_array) { return 1; }
-
-int Param::get_degree_from_array(int *degree_array) { return 0; }
-
-int Constant::get_degree_from_array(int *degree_array) { return 0; }
-
-int Expression::get_degree_from_array(int *degree_array) {
-  return degree_array[n_operators - 1];
-}
-
-int Operator::get_degree_from_array(int *degree_array) {
-  return degree_array[index];
-}
-
-void LinearOperator::propagate_degree_forward(int *degrees, double *values) {
-  degrees[index] = 1;
-}
-
-void SumOperator::propagate_degree_forward(int *degrees, double *values) {
-  int deg = 0;
-  int _deg;
-  for (unsigned int i = 0; i < nargs; ++i) {
-    _deg = operands[i]->get_degree_from_array(degrees);
-    if (_deg > deg) {
-      deg = _deg;
-    }
-  }
-  degrees[index] = deg;
-}
-
-void MultiplyOperator::propagate_degree_forward(int *degrees, double *values) {
-  degrees[index] = operand1->get_degree_from_array(degrees) +
-                   operand2->get_degree_from_array(degrees);
-}
-
-void ExternalOperator::propagate_degree_forward(int *degrees, double *values) {
-  // External functions are always considered nonlinear
-  // Anything larger than 2 is nonlinear
-  degrees[index] = 3;
-}
-
-void DivideOperator::propagate_degree_forward(int *degrees, double *values) {
-  // anything larger than 2 is nonlinear
-  degrees[index] = std::max(operand1->get_degree_from_array(degrees),
-                            3 * (operand2->get_degree_from_array(degrees)));
-}
-
-void PowerOperator::propagate_degree_forward(int *degrees, double *values) {
-  if (operand2->get_degree_from_array(degrees) != 0) {
-    degrees[index] = 3;
-  } else {
-    double val2 = operand2->get_value_from_array(values);
-    double intpart;
-    if (std::modf(val2, &intpart) == 0.0) {
-      degrees[index] = operand1->get_degree_from_array(degrees) * (int)val2;
-    } else {
-      degrees[index] = 3;
-    }
-  }
-}
-
-void NegationOperator::propagate_degree_forward(int *degrees, double *values) {
-  degrees[index] = operand->get_degree_from_array(degrees);
-}
-
-void UnaryOperator::propagate_degree_forward(int *degrees, double *values) {
-  if (operand->get_degree_from_array(degrees) == 0) {
-    degrees[index] = 0;
-  } else {
-    degrees[index] = 3;
-  }
-}
-
-std::string Var::__str__() { return name; }
-
-std::string Param::__str__() { return name; }
-
-std::string Constant::__str__() { return std::to_string(value); }
-
-std::string Expression::__str__() {
-  std::string *string_array = new std::string[n_operators];
-  std::shared_ptr<Operator> oper;
-  for (unsigned int i = 0; i < n_operators; ++i) {
-    oper = operators[i];
-    oper->index = i;
-    oper->print(string_array);
-  }
-  std::string res = string_array[n_operators - 1];
-  delete[] string_array;
-  return res;
-}
-
-std::string Leaf::get_string_from_array(std::string *string_array) {
-  return __str__();
-}
-
-std::string Expression::get_string_from_array(std::string *string_array) {
-  return string_array[n_operators - 1];
-}
-
-std::string Operator::get_string_from_array(std::string *string_array) {
-  return string_array[index];
-}
-
-void MultiplyOperator::print(std::string *string_array) {
-  string_array[index] =
-      ("(" + operand1->get_string_from_array(string_array) + "*" +
-       operand2->get_string_from_array(string_array) + ")");
-}
-
-void ExternalOperator::print(std::string *string_array) {
-  std::string res = function_name + "(";
-  for (unsigned int i = 0; i < (nargs - 1); ++i) {
-    res += operands[i]->get_string_from_array(string_array);
-    res += ", ";
-  }
-  res += operands[nargs - 1]->get_string_from_array(string_array);
-  res += ")";
-  string_array[index] = res;
-}
-
-void DivideOperator::print(std::string *string_array) {
-  string_array[index] =
-      ("(" + operand1->get_string_from_array(string_array) + "/" +
-       operand2->get_string_from_array(string_array) + ")");
-}
-
-void PowerOperator::print(std::string *string_array) {
-  string_array[index] =
-      ("(" + operand1->get_string_from_array(string_array) + "**" +
-       operand2->get_string_from_array(string_array) + ")");
-}
-
-void NegationOperator::print(std::string *string_array) {
-  string_array[index] =
-      ("(-" + operand->get_string_from_array(string_array) + ")");
-}
-
-void ExpOperator::print(std::string *string_array) {
-  string_array[index] =
-      ("exp(" + operand->get_string_from_array(string_array) + ")");
-}
-
-void LogOperator::print(std::string *string_array) {
-  string_array[index] =
-      ("log(" + operand->get_string_from_array(string_array) + ")");
-}
-
-void AbsOperator::print(std::string *string_array) {
-  string_array[index] =
-      ("abs(" + operand->get_string_from_array(string_array) + ")");
-}
-
-void SqrtOperator::print(std::string *string_array) {
-  string_array[index] =
-      ("sqrt(" + operand->get_string_from_array(string_array) + ")");
-}
-
-void Log10Operator::print(std::string *string_array) {
-  string_array[index] =
-      ("log10(" + operand->get_string_from_array(string_array) + ")");
-}
-
-void SinOperator::print(std::string *string_array) {
-  string_array[index] =
-      ("sin(" + operand->get_string_from_array(string_array) + ")");
-}
-
-void CosOperator::print(std::string *string_array) {
-  string_array[index] =
-      ("cos(" + operand->get_string_from_array(string_array) + ")");
-}
-
-void TanOperator::print(std::string *string_array) {
-  string_array[index] =
-      ("tan(" + operand->get_string_from_array(string_array) + ")");
-}
-
-void AsinOperator::print(std::string *string_array) {
-  string_array[index] =
-      ("asin(" + operand->get_string_from_array(string_array) + ")");
-}
-
-void AcosOperator::print(std::string *string_array) {
-  string_array[index] =
-      ("acos(" + operand->get_string_from_array(string_array) + ")");
-}
-
-void AtanOperator::print(std::string *string_array) {
-  string_array[index] =
-      ("atan(" + operand->get_string_from_array(string_array) + ")");
-}
-
-void LinearOperator::print(std::string *string_array) {
-  std::string res = "(" + constant->__str__();
-  for (unsigned int i = 0; i < nterms; ++i) {
-    res += " + " + coefficients[i]->__str__() + "*" + variables[i]->__str__();
-  }
-  res += ")";
-  string_array[index] = res;
-}
-
-void SumOperator::print(std::string *string_array) {
-  std::string res = "(" + operands[0]->get_string_from_array(string_array);
-  for (unsigned int i = 1; i < nargs; ++i) {
-    res += " + " + operands[i]->get_string_from_array(string_array);
-  }
-  res += ")";
-  string_array[index] = res;
-}
-
-std::shared_ptr<std::vector<std::shared_ptr<Node>>>
-Leaf::get_prefix_notation() {
-  std::shared_ptr<std::vector<std::shared_ptr<Node>>> res =
-      std::make_shared<std::vector<std::shared_ptr<Node>>>();
-  res->push_back(shared_from_this());
-  return res;
-}
-
-std::shared_ptr<std::vector<std::shared_ptr<Node>>>
-Expression::get_prefix_notation() {
-  std::shared_ptr<std::vector<std::shared_ptr<Node>>> res =
-      std::make_shared<std::vector<std::shared_ptr<Node>>>();
-  std::shared_ptr<std::vector<std::shared_ptr<Node>>> stack =
-      std::make_shared<std::vector<std::shared_ptr<Node>>>();
-  std::shared_ptr<Node> node;
-  stack->push_back(operators[n_operators - 1]);
-  while (stack->size() > 0) {
-    node = stack->back();
-    stack->pop_back();
-    res->push_back(node);
-    node->fill_prefix_notation_stack(stack);
-  }
-
-  return res;
-}
-
-void BinaryOperator::fill_prefix_notation_stack(
-    std::shared_ptr<std::vector<std::shared_ptr<Node>>> stack) {
-  stack->push_back(operand2);
-  stack->push_back(operand1);
-}
-
-void UnaryOperator::fill_prefix_notation_stack(
-    std::shared_ptr<std::vector<std::shared_ptr<Node>>> stack) {
-  stack->push_back(operand);
-}
-
-void SumOperator::fill_prefix_notation_stack(
-    std::shared_ptr<std::vector<std::shared_ptr<Node>>> stack) {
-  int ndx = nargs - 1;
-  while (ndx >= 0) {
-    stack->push_back(operands[ndx]);
-    ndx -= 1;
-  }
-}
-
-void LinearOperator::fill_prefix_notation_stack(
-    std::shared_ptr<std::vector<std::shared_ptr<Node>>> stack) {
-  ; // This is treated as a leaf in this context; write_nl_string will take care
-    // of it
-}
-
-void ExternalOperator::fill_prefix_notation_stack(
-    std::shared_ptr<std::vector<std::shared_ptr<Node>>> stack) {
-  int i = nargs - 1;
-  while (i >= 0) {
-    stack->push_back(operands[i]);
-    i -= 1;
-  }
-}
-
-void Var::write_nl_string(std::ofstream &f) { f << "v" << index << "\n"; }
-
-void Param::write_nl_string(std::ofstream &f) { f << "n" << value << "\n"; }
-
-void Constant::write_nl_string(std::ofstream &f) { f << "n" << value << "\n"; }
-
-void Expression::write_nl_string(std::ofstream &f) {
-  std::shared_ptr<std::vector<std::shared_ptr<Node>>> prefix_notation =
-      get_prefix_notation();
-  for (std::shared_ptr<Node> &node : *(prefix_notation)) {
-    node->write_nl_string(f);
-  }
-}
-
-void MultiplyOperator::write_nl_string(std::ofstream &f) { f << "o2\n"; }
-
-void ExternalOperator::write_nl_string(std::ofstream &f) {
-  f << "f" << external_function_index << " " << nargs << "\n";
-}
-
-void SumOperator::write_nl_string(std::ofstream &f) {
-  if (nargs == 2) {
-    f << "o0\n";
-  } else {
-    f << "o54\n";
-    f << nargs << "\n";
-  }
-}
-
-void LinearOperator::write_nl_string(std::ofstream &f) {
-  bool has_const =
-      (!constant->is_constant_type()) || (constant->evaluate() != 0);
-  unsigned int n_sum_args = nterms + (has_const ? 1 : 0);
-  if (n_sum_args == 2) {
-    f << "o0\n";
-  } else {
-    f << "o54\n";
-    f << n_sum_args << "\n";
-  }
-  if (has_const)
-    f << "n" << constant->evaluate() << "\n";
-  for (unsigned int ndx = 0; ndx < nterms; ++ndx) {
-    f << "o2\n";
-    f << "n" << coefficients[ndx]->evaluate() << "\n";
-    variables[ndx]->write_nl_string(f);
-  }
-}
-
-void DivideOperator::write_nl_string(std::ofstream &f) { f << "o3\n"; }
-
-void PowerOperator::write_nl_string(std::ofstream &f) { f << "o5\n"; }
-
-void NegationOperator::write_nl_string(std::ofstream &f) { f << "o16\n"; }
-
-void ExpOperator::write_nl_string(std::ofstream &f) { f << "o44\n"; }
-
-void LogOperator::write_nl_string(std::ofstream &f) { f << "o43\n"; }
-
-void AbsOperator::write_nl_string(std::ofstream &f) { f << "o15\n"; }
-
-void SqrtOperator::write_nl_string(std::ofstream &f) { f << "o39\n"; }
-
-void Log10Operator::write_nl_string(std::ofstream &f) { f << "o42\n"; }
-
-void SinOperator::write_nl_string(std::ofstream &f) { f << "o41\n"; }
-
-void CosOperator::write_nl_string(std::ofstream &f) { f << "o46\n"; }
-
-void TanOperator::write_nl_string(std::ofstream &f) { f << "o38\n"; }
-
-void AsinOperator::write_nl_string(std::ofstream &f) { f << "o51\n"; }
-
-void AcosOperator::write_nl_string(std::ofstream &f) { f << "o53\n"; }
-
-void AtanOperator::write_nl_string(std::ofstream &f) { f << "o49\n"; }
-
-bool BinaryOperator::is_binary_operator() { return true; }
-
-bool UnaryOperator::is_unary_operator() { return true; }
-
-bool LinearOperator::is_linear_operator() { return true; }
-
-bool SumOperator::is_sum_operator() { return true; }
-
-bool MultiplyOperator::is_multiply_operator() { return true; }
-
-bool DivideOperator::is_divide_operator() { return true; }
-
-bool PowerOperator::is_power_operator() { return true; }
-
-bool NegationOperator::is_negation_operator() { return true; }
-
-bool ExpOperator::is_exp_operator() { return true; }
-
-bool LogOperator::is_log_operator() { return true; }
-
-bool AbsOperator::is_abs_operator() { return true; }
-
-bool SqrtOperator::is_sqrt_operator() { return true; }
-
-bool ExternalOperator::is_external_operator() { return true; }
-
-void Leaf::fill_expression(std::shared_ptr<Operator> *oper_array,
-                           int &oper_ndx) {
-  ;
-}
-
-void Expression::fill_expression(std::shared_ptr<Operator> *oper_array,
-                                 int &oper_ndx) {
-  throw std::runtime_error("This should not happen");
-}
-
-void BinaryOperator::fill_expression(std::shared_ptr<Operator> *oper_array,
-                                     int &oper_ndx) {
-  oper_ndx -= 1;
-  oper_array[oper_ndx] = shared_from_this();
-  // The order does not actually matter here. It
-  // will just be easier to debug this way.
-  operand2->fill_expression(oper_array, oper_ndx);
-  operand1->fill_expression(oper_array, oper_ndx);
-}
-
-void UnaryOperator::fill_expression(std::shared_ptr<Operator> *oper_array,
-                                    int &oper_ndx) {
-  oper_ndx -= 1;
-  oper_array[oper_ndx] = shared_from_this();
-  operand->fill_expression(oper_array, oper_ndx);
-}
-
-void LinearOperator::fill_expression(std::shared_ptr<Operator> *oper_array,
-                                     int &oper_ndx) {
-  oper_ndx -= 1;
-  oper_array[oper_ndx] = shared_from_this();
-}
-
-void SumOperator::fill_expression(std::shared_ptr<Operator> *oper_array,
-                                  int &oper_ndx) {
-  oper_ndx -= 1;
-  oper_array[oper_ndx] = shared_from_this();
-  // The order does not actually matter here. It
-  // will just be easier to debug this way.
-  int arg_ndx = nargs - 1;
-  while (arg_ndx >= 0) {
-    operands[arg_ndx]->fill_expression(oper_array, oper_ndx);
-    arg_ndx -= 1;
-  }
-}
-
-void ExternalOperator::fill_expression(std::shared_ptr<Operator> *oper_array,
-                                       int &oper_ndx) {
-  oper_ndx -= 1;
-  oper_array[oper_ndx] = shared_from_this();
-  // The order does not actually matter here. It
-  // will just be easier to debug this way.
-  int arg_ndx = nargs - 1;
-  while (arg_ndx >= 0) {
-    operands[arg_ndx]->fill_expression(oper_array, oper_ndx);
-    arg_ndx -= 1;
-  }
-}
-
-double Leaf::get_lb_from_array(double *lbs) { return value; }
-
-double Leaf::get_ub_from_array(double *ubs) { return value; }
-
-double Var::get_lb_from_array(double *lbs) { return get_lb(); }
-
-double Var::get_ub_from_array(double *ubs) { return get_ub(); }
-
-double Expression::get_lb_from_array(double *lbs) {
-  return lbs[n_operators - 1];
-}
-
-double Expression::get_ub_from_array(double *ubs) {
-  return ubs[n_operators - 1];
-}
-
-double Operator::get_lb_from_array(double *lbs) { return lbs[index]; }
-
-double Operator::get_ub_from_array(double *ubs) { return ubs[index]; }
-
-void Leaf::set_bounds_in_array(double new_lb, double new_ub, double *lbs,
-                               double *ubs, double feasibility_tol,
-                               double integer_tol, double improvement_tol,
-                               std::set<std::shared_ptr<Var>> &improved_vars) {
-  if (new_lb < value - feasibility_tol || new_lb > value + feasibility_tol) {
-    throw InfeasibleConstraintException(
-        "Infeasible constraint; bounds computed on parameter or constant "
-        "disagree with the value of the parameter or constant\n  value: " +
-        std::to_string(value) + "\n  computed LB: " + std::to_string(new_lb) +
-        "\n computed UB: " + std::to_string(new_ub));
-  }
-
-  if (new_ub < value - feasibility_tol || new_ub > value + feasibility_tol) {
-    throw InfeasibleConstraintException(
-        "Infeasible constraint; bounds computed on parameter or constant "
-        "disagree with the value of the parameter or constant\n  value: " +
-        std::to_string(value) + "\n  computed LB: " + std::to_string(new_lb) +
-        "\n computed UB: " + std::to_string(new_ub));
-  }
-}
-
-void Var::set_bounds_in_array(double new_lb, double new_ub, double *lbs,
-                              double *ubs, double feasibility_tol,
-                              double integer_tol, double improvement_tol,
-                              std::set<std::shared_ptr<Var>> &improved_vars) {
-  if (new_lb > new_ub) {
-    if (new_lb - feasibility_tol > new_ub)
-      throw InfeasibleConstraintException(
-          "Infeasible constraint; The computed lower bound for a variable is "
-          "larger than the computed upper bound.\n  computed LB: " +
-          std::to_string(new_lb) +
-          "\n  computed UB: " + std::to_string(new_ub));
-    else {
-      new_lb -= feasibility_tol;
-      new_ub += feasibility_tol;
-    }
-  }
-  if (new_lb >= inf)
-    throw InfeasibleConstraintException(
-        "Infeasible constraint; The compute lower bound for " + name +
-        " is inf");
-  if (new_ub <= -inf)
-    throw InfeasibleConstraintException(
-        "Infeasible constraint; The computed upper bound for " + name +
-        " is -inf");
-
-  if (domain == integers || domain == binary) {
-    if (new_lb > -inf) {
-      double lb_floor = floor(new_lb);
-      double lb_ceil = ceil(new_lb - integer_tol);
-      if (lb_floor > lb_ceil)
-        new_lb = lb_floor;
-      else
-        new_lb = lb_ceil;
-    }
-    if (new_ub < inf) {
-      double ub_ceil = ceil(new_ub);
-      double ub_floor = floor(new_ub + integer_tol);
-      if (ub_ceil < ub_floor)
-        new_ub = ub_ceil;
-      else
-        new_ub = ub_floor;
-    }
-  }
-
-  double current_lb = get_lb();
-  double current_ub = get_ub();
-
-  if (new_lb > current_lb + improvement_tol ||
-      new_ub < current_ub - improvement_tol)
-    improved_vars.insert(shared_from_this());
-
-  if (new_lb > current_lb) {
-    if (lb->is_leaf())
-      std::dynamic_pointer_cast<Leaf>(lb)->value = new_lb;
-    else
-      throw py::value_error(
-          "variable bounds cannot be expressions when performing FBBT");
-  }
-
-  if (new_ub < current_ub) {
-    if (ub->is_leaf())
-      std::dynamic_pointer_cast<Leaf>(ub)->value = new_ub;
-    else
-      throw py::value_error(
-          "variable bounds cannot be expressions when performing FBBT");
-  }
-}
-
-void Expression::set_bounds_in_array(
-    double new_lb, double new_ub, double *lbs, double *ubs,
-    double feasibility_tol, double integer_tol, double improvement_tol,
-    std::set<std::shared_ptr<Var>> &improved_vars) {
-  lbs[n_operators - 1] = new_lb;
-  ubs[n_operators - 1] = new_ub;
-}
-
-void Operator::set_bounds_in_array(
-    double new_lb, double new_ub, double *lbs, double *ubs,
-    double feasibility_tol, double integer_tol, double improvement_tol,
-    std::set<std::shared_ptr<Var>> &improved_vars) {
-  lbs[index] = new_lb;
-  ubs[index] = new_ub;
-}
-
-void Expression::propagate_bounds_forward(double *lbs, double *ubs,
-                                          double feasibility_tol,
-                                          double integer_tol) {
-  for (unsigned int ndx = 0; ndx < n_operators; ++ndx) {
-    operators[ndx]->index = ndx;
-    operators[ndx]->propagate_bounds_forward(lbs, ubs, feasibility_tol,
-                                             integer_tol);
-  }
-}
-
-void Expression::propagate_bounds_backward(
-    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
-  int ndx = n_operators - 1;
-  while (ndx >= 0) {
-    operators[ndx]->propagate_bounds_backward(
-        lbs, ubs, feasibility_tol, integer_tol, improvement_tol, improved_vars);
-    ndx -= 1;
-  }
-}
-
-void Operator::propagate_bounds_forward(double *lbs, double *ubs,
-                                        double feasibility_tol,
-                                        double integer_tol) {
-  lbs[index] = -inf;
-  ubs[index] = inf;
-}
-
-void Operator::propagate_bounds_backward(
-    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
-  ;
-}
-
-void MultiplyOperator::propagate_bounds_forward(double *lbs, double *ubs,
-                                                double feasibility_tol,
-                                                double integer_tol) {
-  if (operand1 == operand2) {
-    interval_power(operand1->get_lb_from_array(lbs),
-                   operand1->get_ub_from_array(ubs), 2, 2, &lbs[index],
-                   &ubs[index], feasibility_tol);
-  } else {
-    interval_mul(operand1->get_lb_from_array(lbs),
-                 operand1->get_ub_from_array(ubs),
-                 operand2->get_lb_from_array(lbs),
-                 operand2->get_ub_from_array(ubs), &lbs[index], &ubs[index]);
-  }
-}
-
-void MultiplyOperator::propagate_bounds_backward(
-    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
-  double xl = operand1->get_lb_from_array(lbs);
-  double xu = operand1->get_ub_from_array(ubs);
-  double yl = operand2->get_lb_from_array(lbs);
-  double yu = operand2->get_ub_from_array(ubs);
-  double lb = get_lb_from_array(lbs);
-  double ub = get_ub_from_array(ubs);
-
-  double new_xl, new_xu, new_yl, new_yu;
-
-  if (operand1 == operand2) {
-    _inverse_power1(lb, ub, 2, 2, xl, xu, &new_xl, &new_xu, feasibility_tol);
-    new_yl = new_xl;
-    new_yu = new_xu;
-  } else {
-    interval_div(lb, ub, yl, yu, &new_xl, &new_xu, feasibility_tol);
-    interval_div(lb, ub, xl, xu, &new_yl, &new_yu, feasibility_tol);
-  }
-
-  if (new_xl > xl)
-    xl = new_xl;
-  if (new_xu < xu)
-    xu = new_xu;
-  operand1->set_bounds_in_array(xl, xu, lbs, ubs, feasibility_tol, integer_tol,
-                                improvement_tol, improved_vars);
-
-  if (new_yl > yl)
-    yl = new_yl;
-  if (new_yu < yu)
-    yu = new_yu;
-  operand2->set_bounds_in_array(yl, yu, lbs, ubs, feasibility_tol, integer_tol,
-                                improvement_tol, improved_vars);
-}
-
-void SumOperator::propagate_bounds_forward(double *lbs, double *ubs,
-                                           double feasibility_tol,
-                                           double integer_tol) {
-  double lb = operands[0]->get_lb_from_array(lbs);
-  double ub = operands[0]->get_ub_from_array(ubs);
-  double tmp_lb;
-  double tmp_ub;
-
-  for (unsigned int ndx = 1; ndx < nargs; ++ndx) {
-    interval_add(lb, ub, operands[ndx]->get_lb_from_array(lbs),
-                 operands[ndx]->get_ub_from_array(ubs), &tmp_lb, &tmp_ub);
-    lb = tmp_lb;
-    ub = tmp_ub;
-  }
-
-  lbs[index] = lb;
-  ubs[index] = ub;
-}
-
-void SumOperator::propagate_bounds_backward(
-    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
-  double *accumulated_lbs = new double[nargs];
-  double *accumulated_ubs = new double[nargs];
-
-  accumulated_lbs[0] = operands[0]->get_lb_from_array(lbs);
-  accumulated_ubs[0] = operands[0]->get_ub_from_array(ubs);
-  for (unsigned int ndx = 1; ndx < nargs; ++ndx) {
-    interval_add(accumulated_lbs[ndx - 1], accumulated_ubs[ndx - 1],
-                 operands[ndx]->get_lb_from_array(lbs),
-                 operands[ndx]->get_ub_from_array(ubs), &accumulated_lbs[ndx],
-                 &accumulated_ubs[ndx]);
-  }
-
-  double new_sum_lb = get_lb_from_array(lbs);
-  double new_sum_ub = get_ub_from_array(ubs);
-
-  if (new_sum_lb > accumulated_lbs[nargs - 1])
-    accumulated_lbs[nargs - 1] = new_sum_lb;
-  if (new_sum_ub < accumulated_ubs[nargs - 1])
-    accumulated_ubs[nargs - 1] = new_sum_ub;
-
-  double lb0, ub0, lb1, ub1, lb2, ub2, _lb1, _ub1, _lb2, _ub2;
-
-  int ndx = nargs - 1;
-  while (ndx >= 1) {
-    lb0 = accumulated_lbs[ndx];
-    ub0 = accumulated_ubs[ndx];
-    lb1 = accumulated_lbs[ndx - 1];
-    ub1 = accumulated_ubs[ndx - 1];
-    lb2 = operands[ndx]->get_lb_from_array(lbs);
-    ub2 = operands[ndx]->get_ub_from_array(ubs);
-    interval_sub(lb0, ub0, lb2, ub2, &_lb1, &_ub1);
-    interval_sub(lb0, ub0, lb1, ub1, &_lb2, &_ub2);
-    if (_lb1 > lb1)
-      lb1 = _lb1;
-    if (_ub1 < ub1)
-      ub1 = _ub1;
-    if (_lb2 > lb2)
-      lb2 = _lb2;
-    if (_ub2 < ub2)
-      ub2 = _ub2;
-    accumulated_lbs[ndx - 1] = lb1;
-    accumulated_ubs[ndx - 1] = ub1;
-    operands[ndx]->set_bounds_in_array(lb2, ub2, lbs, ubs, feasibility_tol,
-                                       integer_tol, improvement_tol,
-                                       improved_vars);
-    ndx -= 1;
-  }
-
-  // take care of ndx = 0
-  lb1 = operands[0]->get_lb_from_array(lbs);
-  ub1 = operands[0]->get_ub_from_array(ubs);
-  _lb1 = accumulated_lbs[0];
-  _ub1 = accumulated_ubs[0];
-  if (_lb1 > lb1)
-    lb1 = _lb1;
-  if (_ub1 < ub1)
-    ub1 = _ub1;
-  operands[0]->set_bounds_in_array(lb1, ub1, lbs, ubs, feasibility_tol,
-                                   integer_tol, improvement_tol, improved_vars);
-
-  delete[] accumulated_lbs;
-  delete[] accumulated_ubs;
-}
-
-void LinearOperator::propagate_bounds_forward(double *lbs, double *ubs,
-                                              double feasibility_tol,
-                                              double integer_tol) {
-  double lb = constant->evaluate();
-  double ub = lb;
-  double tmp_lb;
-  double tmp_ub;
-  double coef;
-
-  for (unsigned int ndx = 0; ndx < nterms; ++ndx) {
-    coef = coefficients[ndx]->evaluate();
-    interval_mul(coef, coef, variables[ndx]->get_lb(), variables[ndx]->get_ub(),
-                 &tmp_lb, &tmp_ub);
-    interval_add(lb, ub, tmp_lb, tmp_ub, &lb, &ub);
-  }
-
-  lbs[index] = lb;
-  ubs[index] = ub;
-}
-
-void LinearOperator::propagate_bounds_backward(
-    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
-  double *accumulated_lbs = new double[nterms + 1];
-  double *accumulated_ubs = new double[nterms + 1];
-
-  double coef;
-
-  accumulated_lbs[0] = constant->evaluate();
-  accumulated_ubs[0] = constant->evaluate();
-  for (unsigned int ndx = 0; ndx < nterms; ++ndx) {
-    coef = coefficients[ndx]->evaluate();
-    interval_mul(coef, coef, variables[ndx]->get_lb(), variables[ndx]->get_ub(),
-                 &accumulated_lbs[ndx + 1], &accumulated_ubs[ndx + 1]);
-    interval_add(accumulated_lbs[ndx], accumulated_ubs[ndx],
-                 accumulated_lbs[ndx + 1], accumulated_ubs[ndx + 1],
-                 &accumulated_lbs[ndx + 1], &accumulated_ubs[ndx + 1]);
-  }
-
-  double new_sum_lb = get_lb_from_array(lbs);
-  double new_sum_ub = get_ub_from_array(ubs);
-
-  if (new_sum_lb > accumulated_lbs[nterms])
-    accumulated_lbs[nterms] = new_sum_lb;
-  if (new_sum_ub < accumulated_ubs[nterms])
-    accumulated_ubs[nterms] = new_sum_ub;
-
-  double lb0, ub0, lb1, ub1, lb2, ub2, _lb1, _ub1, _lb2, _ub2, new_v_lb,
-      new_v_ub;
-
-  int ndx = nterms - 1;
-  while (ndx >= 0) {
-    lb0 = accumulated_lbs[ndx + 1];
-    ub0 = accumulated_ubs[ndx + 1];
-    lb1 = accumulated_lbs[ndx];
-    ub1 = accumulated_ubs[ndx];
-    coef = coefficients[ndx]->evaluate();
-    interval_mul(coef, coef, variables[ndx]->get_lb(), variables[ndx]->get_ub(),
-                 &lb2, &ub2);
-    interval_sub(lb0, ub0, lb2, ub2, &_lb1, &_ub1);
-    interval_sub(lb0, ub0, lb1, ub1, &_lb2, &_ub2);
-    if (_lb1 > lb1)
-      lb1 = _lb1;
-    if (_ub1 < ub1)
-      ub1 = _ub1;
-    if (_lb2 > lb2)
-      lb2 = _lb2;
-    if (_ub2 < ub2)
-      ub2 = _ub2;
-    accumulated_lbs[ndx] = lb1;
-    accumulated_ubs[ndx] = ub1;
-    interval_div(lb2, ub2, coef, coef, &new_v_lb, &new_v_ub, feasibility_tol);
-    variables[ndx]->set_bounds_in_array(new_v_lb, new_v_ub, lbs, ubs,
-                                        feasibility_tol, integer_tol,
-                                        improvement_tol, improved_vars);
-    ndx -= 1;
-  }
-
-  delete[] accumulated_lbs;
-  delete[] accumulated_ubs;
-}
-
-void DivideOperator::propagate_bounds_forward(double *lbs, double *ubs,
-                                              double feasibility_tol,
-                                              double integer_tol) {
-  interval_div(
-      operand1->get_lb_from_array(lbs), operand1->get_ub_from_array(ubs),
-      operand2->get_lb_from_array(lbs), operand2->get_ub_from_array(ubs),
-      &lbs[index], &ubs[index], feasibility_tol);
-}
-
-void DivideOperator::propagate_bounds_backward(
-    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
-  double xl = operand1->get_lb_from_array(lbs);
-  double xu = operand1->get_ub_from_array(ubs);
-  double yl = operand2->get_lb_from_array(lbs);
-  double yu = operand2->get_ub_from_array(ubs);
-  double lb = get_lb_from_array(lbs);
-  double ub = get_ub_from_array(ubs);
-
-  double new_xl;
-  double new_xu;
-  double new_yl;
-  double new_yu;
-
-  interval_mul(lb, ub, yl, yu, &new_xl, &new_xu);
-  interval_div(xl, xu, lb, ub, &new_yl, &new_yu, feasibility_tol);
-
-  if (new_xl > xl)
-    xl = new_xl;
-  if (new_xu < xu)
-    xu = new_xu;
-  operand1->set_bounds_in_array(xl, xu, lbs, ubs, feasibility_tol, integer_tol,
-                                improvement_tol, improved_vars);
-
-  if (new_yl > yl)
-    yl = new_yl;
-  if (new_yu < yu)
-    yu = new_yu;
-  operand2->set_bounds_in_array(yl, yu, lbs, ubs, feasibility_tol, integer_tol,
-                                improvement_tol, improved_vars);
-}
-
-void NegationOperator::propagate_bounds_forward(double *lbs, double *ubs,
-                                                double feasibility_tol,
-                                                double integer_tol) {
-  interval_sub(0, 0, operand->get_lb_from_array(lbs),
-               operand->get_ub_from_array(ubs), &lbs[index], &ubs[index]);
-}
-
-void NegationOperator::propagate_bounds_backward(
-    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
-  double xl = operand->get_lb_from_array(lbs);
-  double xu = operand->get_ub_from_array(ubs);
-  double lb = get_lb_from_array(lbs);
-  double ub = get_ub_from_array(ubs);
-
-  double new_xl;
-  double new_xu;
-
-  interval_sub(0, 0, lb, ub, &new_xl, &new_xu);
-
-  if (new_xl > xl)
-    xl = new_xl;
-  if (new_xu < xu)
-    xu = new_xu;
-  operand->set_bounds_in_array(xl, xu, lbs, ubs, feasibility_tol, integer_tol,
-                               improvement_tol, improved_vars);
-}
-
-void PowerOperator::propagate_bounds_forward(double *lbs, double *ubs,
-                                             double feasibility_tol,
-                                             double integer_tol) {
-  interval_power(
-      operand1->get_lb_from_array(lbs), operand1->get_ub_from_array(ubs),
-      operand2->get_lb_from_array(lbs), operand2->get_ub_from_array(ubs),
-      &lbs[index], &ubs[index], feasibility_tol);
-}
-
-void PowerOperator::propagate_bounds_backward(
-    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
-  double xl = operand1->get_lb_from_array(lbs);
-  double xu = operand1->get_ub_from_array(ubs);
-  double yl = operand2->get_lb_from_array(lbs);
-  double yu = operand2->get_ub_from_array(ubs);
-  double lb = get_lb_from_array(lbs);
-  double ub = get_ub_from_array(ubs);
-
-  double new_xl, new_xu, new_yl, new_yu;
-  _inverse_power1(lb, ub, yl, yu, xl, xu, &new_xl, &new_xu, feasibility_tol);
-  if (yl != yu)
-    _inverse_power2(lb, ub, xl, xu, &new_yl, &new_yu, feasibility_tol);
-  else {
-    new_yl = yl;
-    new_yu = yu;
-  }
-
-  if (new_xl > xl)
-    xl = new_xl;
-  if (new_xu < xu)
-    xu = new_xu;
-  operand1->set_bounds_in_array(xl, xu, lbs, ubs, feasibility_tol, integer_tol,
-                                improvement_tol, improved_vars);
-
-  if (new_yl > yl)
-    yl = new_yl;
-  if (new_yu < yu)
-    yu = new_yu;
-  operand2->set_bounds_in_array(yl, yu, lbs, ubs, feasibility_tol, integer_tol,
-                                improvement_tol, improved_vars);
-}
-
-void SqrtOperator::propagate_bounds_forward(double *lbs, double *ubs,
-                                            double feasibility_tol,
-                                            double integer_tol) {
-  interval_power(operand->get_lb_from_array(lbs),
-                 operand->get_ub_from_array(ubs), 0.5, 0.5, &lbs[index],
-                 &ubs[index], feasibility_tol);
-}
-
-void SqrtOperator::propagate_bounds_backward(
-    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
-  double xl = operand->get_lb_from_array(lbs);
-  double xu = operand->get_ub_from_array(ubs);
-  double yl = 0.5;
-  double yu = 0.5;
-  double lb = get_lb_from_array(lbs);
-  double ub = get_ub_from_array(ubs);
-
-  double new_xl, new_xu;
-  _inverse_power1(lb, ub, yl, yu, xl, xu, &new_xl, &new_xu, feasibility_tol);
-
-  if (new_xl > xl)
-    xl = new_xl;
-  if (new_xu < xu)
-    xu = new_xu;
-  operand->set_bounds_in_array(xl, xu, lbs, ubs, feasibility_tol, integer_tol,
-                               improvement_tol, improved_vars);
-}
-
-void ExpOperator::propagate_bounds_forward(double *lbs, double *ubs,
-                                           double feasibility_tol,
-                                           double integer_tol) {
-  interval_exp(operand->get_lb_from_array(lbs), operand->get_ub_from_array(ubs),
-               &lbs[index], &ubs[index]);
-}
-
-void ExpOperator::propagate_bounds_backward(
-    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
-  double xl = operand->get_lb_from_array(lbs);
-  double xu = operand->get_ub_from_array(ubs);
-  double lb = get_lb_from_array(lbs);
-  double ub = get_ub_from_array(ubs);
-
-  double new_xl, new_xu;
-  interval_log(lb, ub, &new_xl, &new_xu);
-
-  if (new_xl > xl)
-    xl = new_xl;
-  if (new_xu < xu)
-    xu = new_xu;
-  operand->set_bounds_in_array(xl, xu, lbs, ubs, feasibility_tol, integer_tol,
-                               improvement_tol, improved_vars);
-}
-
-void LogOperator::propagate_bounds_forward(double *lbs, double *ubs,
-                                           double feasibility_tol,
-                                           double integer_tol) {
-  interval_log(operand->get_lb_from_array(lbs), operand->get_ub_from_array(ubs),
-               &lbs[index], &ubs[index]);
-}
-
-void LogOperator::propagate_bounds_backward(
-    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
-  double xl = operand->get_lb_from_array(lbs);
-  double xu = operand->get_ub_from_array(ubs);
-  double lb = get_lb_from_array(lbs);
-  double ub = get_ub_from_array(ubs);
-
-  double new_xl, new_xu;
-  interval_exp(lb, ub, &new_xl, &new_xu);
-
-  if (new_xl > xl)
-    xl = new_xl;
-  if (new_xu < xu)
-    xu = new_xu;
-  operand->set_bounds_in_array(xl, xu, lbs, ubs, feasibility_tol, integer_tol,
-                               improvement_tol, improved_vars);
-}
-
-void AbsOperator::propagate_bounds_forward(double *lbs, double *ubs,
-                                           double feasibility_tol,
-                                           double integer_tol) {
-  interval_abs(operand->get_lb_from_array(lbs), operand->get_ub_from_array(ubs),
-               &lbs[index], &ubs[index]);
-}
-
-void AbsOperator::propagate_bounds_backward(
-    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
-  double xl = operand->get_lb_from_array(lbs);
-  double xu = operand->get_ub_from_array(ubs);
-  double lb = get_lb_from_array(lbs);
-  double ub = get_ub_from_array(ubs);
-
-  double new_xl, new_xu;
-  _inverse_abs(lb, ub, &new_xl, &new_xu);
-
-  if (new_xl > xl)
-    xl = new_xl;
-  if (new_xu < xu)
-    xu = new_xu;
-  operand->set_bounds_in_array(xl, xu, lbs, ubs, feasibility_tol, integer_tol,
-                               improvement_tol, improved_vars);
-}
-
-void Log10Operator::propagate_bounds_forward(double *lbs, double *ubs,
-                                             double feasibility_tol,
-                                             double integer_tol) {
-  interval_log10(operand->get_lb_from_array(lbs),
-                 operand->get_ub_from_array(ubs), &lbs[index], &ubs[index]);
-}
-
-void Log10Operator::propagate_bounds_backward(
-    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
-  double xl = operand->get_lb_from_array(lbs);
-  double xu = operand->get_ub_from_array(ubs);
-  double lb = get_lb_from_array(lbs);
-  double ub = get_ub_from_array(ubs);
-
-  double new_xl, new_xu;
-  interval_power(10, 10, lb, ub, &new_xl, &new_xu, feasibility_tol);
-
-  if (new_xl > xl)
-    xl = new_xl;
-  if (new_xu < xu)
-    xu = new_xu;
-  operand->set_bounds_in_array(xl, xu, lbs, ubs, feasibility_tol, integer_tol,
-                               improvement_tol, improved_vars);
-}
-
-void SinOperator::propagate_bounds_forward(double *lbs, double *ubs,
-                                           double feasibility_tol,
-                                           double integer_tol) {
-  interval_sin(operand->get_lb_from_array(lbs), operand->get_ub_from_array(ubs),
-               &lbs[index], &ubs[index]);
-}
-
-void SinOperator::propagate_bounds_backward(
-    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
-  double xl = operand->get_lb_from_array(lbs);
-  double xu = operand->get_ub_from_array(ubs);
-  double lb = get_lb_from_array(lbs);
-  double ub = get_ub_from_array(ubs);
-
-  double new_xl, new_xu;
-  interval_asin(lb, ub, xl, xu, &new_xl, &new_xu, feasibility_tol);
-
-  if (new_xl > xl)
-    xl = new_xl;
-  if (new_xu < xu)
-    xu = new_xu;
-  operand->set_bounds_in_array(xl, xu, lbs, ubs, feasibility_tol, integer_tol,
-                               improvement_tol, improved_vars);
-}
-
-void CosOperator::propagate_bounds_forward(double *lbs, double *ubs,
-                                           double feasibility_tol,
-                                           double integer_tol) {
-  interval_cos(operand->get_lb_from_array(lbs), operand->get_ub_from_array(ubs),
-               &lbs[index], &ubs[index]);
-}
-
-void CosOperator::propagate_bounds_backward(
-    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
-  double xl = operand->get_lb_from_array(lbs);
-  double xu = operand->get_ub_from_array(ubs);
-  double lb = get_lb_from_array(lbs);
-  double ub = get_ub_from_array(ubs);
-
-  double new_xl, new_xu;
-  interval_acos(lb, ub, xl, xu, &new_xl, &new_xu, feasibility_tol);
-
-  if (new_xl > xl)
-    xl = new_xl;
-  if (new_xu < xu)
-    xu = new_xu;
-  operand->set_bounds_in_array(xl, xu, lbs, ubs, feasibility_tol, integer_tol,
-                               improvement_tol, improved_vars);
-}
-
-void TanOperator::propagate_bounds_forward(double *lbs, double *ubs,
-                                           double feasibility_tol,
-                                           double integer_tol) {
-  interval_tan(operand->get_lb_from_array(lbs), operand->get_ub_from_array(ubs),
-               &lbs[index], &ubs[index]);
-}
-
-void TanOperator::propagate_bounds_backward(
-    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
-  double xl = operand->get_lb_from_array(lbs);
-  double xu = operand->get_ub_from_array(ubs);
-  double lb = get_lb_from_array(lbs);
-  double ub = get_ub_from_array(ubs);
-
-  double new_xl, new_xu;
-  interval_atan(lb, ub, xl, xu, &new_xl, &new_xu);
-
-  if (new_xl > xl)
-    xl = new_xl;
-  if (new_xu < xu)
-    xu = new_xu;
-  operand->set_bounds_in_array(xl, xu, lbs, ubs, feasibility_tol, integer_tol,
-                               improvement_tol, improved_vars);
-}
-
-void AsinOperator::propagate_bounds_forward(double *lbs, double *ubs,
-                                            double feasibility_tol,
-                                            double integer_tol) {
-  interval_asin(operand->get_lb_from_array(lbs),
-                operand->get_ub_from_array(ubs), -inf, inf, &lbs[index],
-                &ubs[index], feasibility_tol);
-}
-
-void AsinOperator::propagate_bounds_backward(
-    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
-  double xl = operand->get_lb_from_array(lbs);
-  double xu = operand->get_ub_from_array(ubs);
-  double lb = get_lb_from_array(lbs);
-  double ub = get_ub_from_array(ubs);
-
-  double new_xl, new_xu;
-  interval_sin(lb, ub, &new_xl, &new_xu);
-
-  if (new_xl > xl)
-    xl = new_xl;
-  if (new_xu < xu)
-    xu = new_xu;
-  operand->set_bounds_in_array(xl, xu, lbs, ubs, feasibility_tol, integer_tol,
-                               improvement_tol, improved_vars);
-}
-
-void AcosOperator::propagate_bounds_forward(double *lbs, double *ubs,
-                                            double feasibility_tol,
-                                            double integer_tol) {
-  interval_acos(operand->get_lb_from_array(lbs),
-                operand->get_ub_from_array(ubs), -inf, inf, &lbs[index],
-                &ubs[index], feasibility_tol);
-}
-
-void AcosOperator::propagate_bounds_backward(
-    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
-  double xl = operand->get_lb_from_array(lbs);
-  double xu = operand->get_ub_from_array(ubs);
-  double lb = get_lb_from_array(lbs);
-  double ub = get_ub_from_array(ubs);
-
-  double new_xl, new_xu;
-  interval_cos(lb, ub, &new_xl, &new_xu);
-
-  if (new_xl > xl)
-    xl = new_xl;
-  if (new_xu < xu)
-    xu = new_xu;
-  operand->set_bounds_in_array(xl, xu, lbs, ubs, feasibility_tol, integer_tol,
-                               improvement_tol, improved_vars);
-}
-
-void AtanOperator::propagate_bounds_forward(double *lbs, double *ubs,
-                                            double feasibility_tol,
-                                            double integer_tol) {
-  interval_atan(operand->get_lb_from_array(lbs),
-                operand->get_ub_from_array(ubs), -inf, inf, &lbs[index],
-                &ubs[index]);
-}
-
-void AtanOperator::propagate_bounds_backward(
-    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
-  double xl = operand->get_lb_from_array(lbs);
-  double xu = operand->get_ub_from_array(ubs);
-  double lb = get_lb_from_array(lbs);
-  double ub = get_ub_from_array(ubs);
-
-  double new_xl, new_xu;
-  interval_tan(lb, ub, &new_xl, &new_xu);
-
-  if (new_xl > xl)
-    xl = new_xl;
-  if (new_xu < xu)
-    xu = new_xu;
-  operand->set_bounds_in_array(xl, xu, lbs, ubs, feasibility_tol, integer_tol,
-                               improvement_tol, improved_vars);
-}
-
-std::vector<std::shared_ptr<Var>> create_vars(int n_vars) {
-  std::vector<std::shared_ptr<Var>> res;
-  for (int i = 0; i < n_vars; ++i) {
-    res.push_back(std::make_shared<Var>());
-  }
-  return res;
-}
-
-std::vector<std::shared_ptr<Param>> create_params(int n_params) {
-  std::vector<std::shared_ptr<Param>> res;
-  for (int i = 0; i < n_params; ++i) {
-    res.push_back(std::make_shared<Param>());
-  }
-  return res;
-}
-
-std::vector<std::shared_ptr<Constant>> create_constants(int n_constants) {
-  std::vector<std::shared_ptr<Constant>> res;
-  for (int i = 0; i < n_constants; ++i) {
-    res.push_back(std::make_shared<Constant>());
-  }
-  return res;
-}
-
-std::shared_ptr<Node>
-appsi_operator_from_pyomo_expr(py::handle expr, py::handle var_map,
-                               py::handle param_map,
-                               PyomoExprTypes &expr_types) {
-  std::shared_ptr<Node> res;
-  ExprType tmp_type =
-      expr_types.expr_type_map[py::type::of(expr)].cast<ExprType>();
-
-  switch (tmp_type) {
-  case py_float: {
-    res = std::make_shared<Constant>(expr.cast<double>());
-    break;
-  }
-  case var: {
-    res = var_map[expr_types.id(expr)].cast<std::shared_ptr<Node>>();
-    break;
-  }
-  case param: {
-    res = param_map[expr_types.id(expr)].cast<std::shared_ptr<Node>>();
-    break;
-  }
-  case product: {
-    res = std::make_shared<MultiplyOperator>();
-    break;
-  }
-  case sum: {
-    res = std::make_shared<SumOperator>(expr.attr("nargs")().cast<int>());
-    break;
-  }
-  case negation: {
-    res = std::make_shared<NegationOperator>();
-    break;
-  }
-  case external_func: {
-    res = std::make_shared<ExternalOperator>(expr.attr("nargs")().cast<int>());
-    std::shared_ptr<ExternalOperator> oper =
-        std::dynamic_pointer_cast<ExternalOperator>(res);
-    oper->function_name =
-        expr.attr("_fcn").attr("_function").cast<std::string>();
-    break;
-  }
-  case power: {
-    res = std::make_shared<PowerOperator>();
-    break;
-  }
-  case division: {
-    res = std::make_shared<DivideOperator>();
-    break;
-  }
-  case unary_func: {
-    std::string function_name = expr.attr("getname")().cast<std::string>();
-    if (function_name == "exp")
-      res = std::make_shared<ExpOperator>();
-    else if (function_name == "log")
-      res = std::make_shared<LogOperator>();
-    else if (function_name == "log10")
-      res = std::make_shared<Log10Operator>();
-    else if (function_name == "sin")
-      res = std::make_shared<SinOperator>();
-    else if (function_name == "cos")
-      res = std::make_shared<CosOperator>();
-    else if (function_name == "tan")
-      res = std::make_shared<TanOperator>();
-    else if (function_name == "asin")
-      res = std::make_shared<AsinOperator>();
-    else if (function_name == "acos")
-      res = std::make_shared<AcosOperator>();
-    else if (function_name == "atan")
-      res = std::make_shared<AtanOperator>();
-    else if (function_name == "sqrt")
-      res = std::make_shared<SqrtOperator>();
-    else
-      throw py::value_error("Unrecognized expression type: " + function_name);
-    break;
-  }
-  case linear: {
-    res = std::make_shared<LinearOperator>(
-        expr_types.len(expr.attr("linear_vars")).cast<int>());
-    break;
-  }
-  case named_expr: {
-    res = appsi_operator_from_pyomo_expr(expr.attr("expr"), var_map, param_map,
-                                         expr_types);
-    break;
-  }
-  case numeric_constant: {
-    res = std::make_shared<Constant>(expr.attr("value").cast<double>());
-    break;
-  }
-  case pyomo_unit: {
-    res = std::make_shared<Constant>(1.0);
-    break;
-  }
-  case unary_abs: {
-    res = std::make_shared<AbsOperator>();
-    break;
-  }
-  default: {
-    throw py::value_error("Unrecognized expression type: " +
-                          expr_types.builtins.attr("str")(py::type::of(expr))
-                              .cast<std::string>());
-    break;
-  }
-  }
-  return res;
-}
-
-void prep_for_repn_helper(py::handle expr, py::handle named_exprs,
-                          py::handle variables, py::handle fixed_vars,
-                          py::handle external_funcs,
-                          PyomoExprTypes &expr_types) {
-  ExprType tmp_type =
-      expr_types.expr_type_map[py::type::of(expr)].cast<ExprType>();
-
-  switch (tmp_type) {
-  case py_float: {
-    break;
-  }
-  case var: {
-    variables[expr_types.id(expr)] = expr;
-    if (expr.attr("fixed").cast<bool>()) {
-      fixed_vars[expr_types.id(expr)] = expr;
-    }
-    break;
-  }
-  case param: {
-    break;
-  }
-  case product: {
-    py::tuple args = expr.attr("_args_");
-    for (py::handle arg : args) {
-      prep_for_repn_helper(arg, named_exprs, variables, fixed_vars,
-                           external_funcs, expr_types);
-    }
-    break;
-  }
-  case sum: {
-    py::tuple args = expr.attr("args");
-    for (py::handle arg : args) {
-      prep_for_repn_helper(arg, named_exprs, variables, fixed_vars,
-                           external_funcs, expr_types);
-    }
-    break;
-  }
-  case negation: {
-    py::tuple args = expr.attr("_args_");
-    for (py::handle arg : args) {
-      prep_for_repn_helper(arg, named_exprs, variables, fixed_vars,
-                           external_funcs, expr_types);
-    }
-    break;
-  }
-  case external_func: {
-    external_funcs[expr_types.id(expr)] = expr;
-    py::tuple args = expr.attr("args");
-    for (py::handle arg : args) {
-      prep_for_repn_helper(arg, named_exprs, variables, fixed_vars,
-                           external_funcs, expr_types);
-    }
-    break;
-  }
-  case power: {
-    py::tuple args = expr.attr("_args_");
-    for (py::handle arg : args) {
-      prep_for_repn_helper(arg, named_exprs, variables, fixed_vars,
-                           external_funcs, expr_types);
-    }
-    break;
-  }
-  case division: {
-    py::tuple args = expr.attr("_args_");
-    for (py::handle arg : args) {
-      prep_for_repn_helper(arg, named_exprs, variables, fixed_vars,
-                           external_funcs, expr_types);
-    }
-    break;
-  }
-  case unary_func: {
-    py::tuple args = expr.attr("_args_");
-    for (py::handle arg : args) {
-      prep_for_repn_helper(arg, named_exprs, variables, fixed_vars,
-                           external_funcs, expr_types);
-    }
-    break;
-  }
-  case linear: {
-    py::list linear_vars = expr.attr("linear_vars");
-    py::list linear_coefs = expr.attr("linear_coefs");
-    for (py::handle arg : linear_vars) {
-      prep_for_repn_helper(arg, named_exprs, variables, fixed_vars,
-                           external_funcs, expr_types);
-    }
-    for (py::handle arg : linear_coefs) {
-      prep_for_repn_helper(arg, named_exprs, variables, fixed_vars,
-                           external_funcs, expr_types);
-    }
-    prep_for_repn_helper(expr.attr("constant"), named_exprs, variables,
-                         fixed_vars, external_funcs, expr_types);
-    break;
-  }
-  case named_expr: {
-    named_exprs[expr_types.id(expr)] = expr;
-    prep_for_repn_helper(expr.attr("expr"), named_exprs, variables, fixed_vars,
-                         external_funcs, expr_types);
-    break;
-  }
-  case numeric_constant: {
-    break;
-  }
-  case pyomo_unit: {
-    break;
-  }
-  case unary_abs: {
-    py::tuple args = expr.attr("_args_");
-    for (py::handle arg : args) {
-      prep_for_repn_helper(arg, named_exprs, variables, fixed_vars,
-                           external_funcs, expr_types);
-    }
-    break;
-  }
-  default: {
-    if (expr_types.builtins.attr("hasattr")(expr, "is_constant").cast<bool>()) {
-      if (expr.attr("is_constant")().cast<bool>())
-        break;
-    }
-    throw py::value_error("Unrecognized expression type: " +
-                          expr_types.builtins.attr("str")(py::type::of(expr))
-                              .cast<std::string>());
-    break;
-  }
-  }
-}
-
-py::tuple prep_for_repn(py::handle expr, PyomoExprTypes &expr_types) {
-  py::dict named_exprs;
-  py::dict variables;
-  py::dict fixed_vars;
-  py::dict external_funcs;
-
-  prep_for_repn_helper(expr, named_exprs, variables, fixed_vars, external_funcs,
-                       expr_types);
-
-  py::list named_expr_list = named_exprs.attr("values")();
-  py::list variable_list = variables.attr("values")();
-  py::list fixed_var_list = fixed_vars.attr("values")();
-  py::list external_func_list = external_funcs.attr("values")();
-
-  py::tuple res = py::make_tuple(named_expr_list, variable_list, fixed_var_list,
-                                 external_func_list);
-  return res;
-}
-
-int build_expression_tree(py::handle pyomo_expr,
-                          std::shared_ptr<Node> appsi_expr, py::handle var_map,
-                          py::handle param_map, PyomoExprTypes &expr_types) {
-  int num_nodes = 0;
-
-  if (expr_types.expr_type_map[py::type::of(pyomo_expr)].cast<ExprType>() ==
-      named_expr)
-    pyomo_expr = pyomo_expr.attr("expr");
-
-  if (appsi_expr->is_leaf()) {
-    ;
-  } else if (appsi_expr->is_binary_operator()) {
-    num_nodes += 1;
-    std::shared_ptr<BinaryOperator> oper =
-        std::dynamic_pointer_cast<BinaryOperator>(appsi_expr);
-    py::list pyomo_args = pyomo_expr.attr("args");
-    oper->operand1 = appsi_operator_from_pyomo_expr(pyomo_args[0], var_map,
-                                                    param_map, expr_types);
-    oper->operand2 = appsi_operator_from_pyomo_expr(pyomo_args[1], var_map,
-                                                    param_map, expr_types);
-    num_nodes += build_expression_tree(pyomo_args[0], oper->operand1, var_map,
-                                       param_map, expr_types);
-    num_nodes += build_expression_tree(pyomo_args[1], oper->operand2, var_map,
-                                       param_map, expr_types);
-  } else if (appsi_expr->is_unary_operator()) {
-    num_nodes += 1;
-    std::shared_ptr<UnaryOperator> oper =
-        std::dynamic_pointer_cast<UnaryOperator>(appsi_expr);
-    py::list pyomo_args = pyomo_expr.attr("args");
-    oper->operand = appsi_operator_from_pyomo_expr(pyomo_args[0], var_map,
-                                                   param_map, expr_types);
-    num_nodes += build_expression_tree(pyomo_args[0], oper->operand, var_map,
-                                       param_map, expr_types);
-  } else if (appsi_expr->is_sum_operator()) {
-    num_nodes += 1;
-    std::shared_ptr<SumOperator> oper =
-        std::dynamic_pointer_cast<SumOperator>(appsi_expr);
-    py::list pyomo_args = pyomo_expr.attr("args");
-    for (unsigned int arg_ndx = 0; arg_ndx < oper->nargs; ++arg_ndx) {
-      oper->operands[arg_ndx] = appsi_operator_from_pyomo_expr(
-          pyomo_args[arg_ndx], var_map, param_map, expr_types);
-      num_nodes +=
-          build_expression_tree(pyomo_args[arg_ndx], oper->operands[arg_ndx],
-                                var_map, param_map, expr_types);
-    }
-  } else if (appsi_expr->is_linear_operator()) {
-    num_nodes += 1;
-    std::shared_ptr<LinearOperator> oper =
-        std::dynamic_pointer_cast<LinearOperator>(appsi_expr);
-    oper->constant = appsi_expr_from_pyomo_expr(pyomo_expr.attr("constant"),
-                                                var_map, param_map, expr_types);
-    py::list pyomo_vars = pyomo_expr.attr("linear_vars");
-    py::list pyomo_coefs = pyomo_expr.attr("linear_coefs");
-    for (unsigned int arg_ndx = 0; arg_ndx < oper->nterms; ++arg_ndx) {
-      oper->variables[arg_ndx] = var_map[expr_types.id(pyomo_vars[arg_ndx])]
-                                     .cast<std::shared_ptr<Var>>();
-      oper->coefficients[arg_ndx] = appsi_expr_from_pyomo_expr(
-          pyomo_coefs[arg_ndx], var_map, param_map, expr_types);
-    }
-  } else if (appsi_expr->is_external_operator()) {
-    num_nodes += 1;
-    std::shared_ptr<ExternalOperator> oper =
-        std::dynamic_pointer_cast<ExternalOperator>(appsi_expr);
-    py::list pyomo_args = pyomo_expr.attr("args");
-    for (unsigned int arg_ndx = 0; arg_ndx < oper->nargs; ++arg_ndx) {
-      oper->operands[arg_ndx] = appsi_operator_from_pyomo_expr(
-          pyomo_args[arg_ndx], var_map, param_map, expr_types);
-      num_nodes +=
-          build_expression_tree(pyomo_args[arg_ndx], oper->operands[arg_ndx],
-                                var_map, param_map, expr_types);
-    }
-  } else {
-    throw py::value_error(
-        "Unrecognized expression type: " +
-        expr_types.builtins.attr("str")(py::type::of(pyomo_expr))
-            .cast<std::string>());
-  }
-  return num_nodes;
-}
-
-std::shared_ptr<ExpressionBase>
-appsi_expr_from_pyomo_expr(py::handle expr, py::handle var_map,
-                           py::handle param_map, PyomoExprTypes &expr_types) {
-  std::shared_ptr<Node> node =
-      appsi_operator_from_pyomo_expr(expr, var_map, param_map, expr_types);
-  int num_nodes =
-      build_expression_tree(expr, node, var_map, param_map, expr_types);
-  if (num_nodes == 0) {
-    return std::dynamic_pointer_cast<ExpressionBase>(node);
-  } else {
-    std::shared_ptr<Expression> res = std::make_shared<Expression>(num_nodes);
-    node->fill_expression(res->operators, num_nodes);
-    return res;
-  }
-}
-
-std::vector<std::shared_ptr<ExpressionBase>>
-appsi_exprs_from_pyomo_exprs(py::list expr_list, py::dict var_map,
-                             py::dict param_map) {
-  PyomoExprTypes expr_types = PyomoExprTypes();
-  int num_exprs = expr_types.builtins.attr("len")(expr_list).cast<int>();
-  std::vector<std::shared_ptr<ExpressionBase>> res(num_exprs);
-
-  int ndx = 0;
-  for (py::handle expr : expr_list) {
-    res[ndx] = appsi_expr_from_pyomo_expr(expr, var_map, param_map, expr_types);
-    ndx += 1;
-  }
-  return res;
-}
-
-void process_pyomo_vars(PyomoExprTypes &expr_types, py::list pyomo_vars,
-                        py::dict var_map, py::dict param_map,
-                        py::dict var_attrs, py::dict rev_var_map,
-                        py::bool_ _set_name, py::handle symbol_map,
-                        py::handle labeler, py::bool_ _update) {
-  py::tuple v_attrs;
-  std::shared_ptr<Var> cv;
-  py::handle v_lb;
-  py::handle v_ub;
-  py::handle v_val;
-  py::tuple domain_interval;
-  py::handle interval_lb;
-  py::handle interval_ub;
-  py::handle interval_step;
-  bool v_fixed;
-  bool set_name = _set_name.cast<bool>();
-  bool update = _update.cast<bool>();
-  double domain_step;
-
-  for (py::handle v : pyomo_vars) {
-    v_attrs = var_attrs[expr_types.id(v)];
-    v_lb = v_attrs[1];
-    v_ub = v_attrs[2];
-    v_fixed = v_attrs[3].cast<bool>();
-    domain_interval = v_attrs[4];
-    v_val = v_attrs[5];
-
-    interval_lb = domain_interval[0];
-    interval_ub = domain_interval[1];
-    interval_step = domain_interval[2];
-    domain_step = interval_step.cast<double>();
-
-    if (update) {
-      cv = var_map[expr_types.id(v)].cast<std::shared_ptr<Var>>();
-    } else {
-      cv = std::make_shared<Var>();
-    }
-
-    if (!(v_lb.is(py::none()))) {
-      cv->lb = appsi_expr_from_pyomo_expr(v_lb, var_map, param_map, expr_types);
-    } else {
-      cv->lb = std::make_shared<Constant>(-inf);
-    }
-    if (!(v_ub.is(py::none()))) {
-      cv->ub = appsi_expr_from_pyomo_expr(v_ub, var_map, param_map, expr_types);
-    } else {
-      cv->ub = std::make_shared<Constant>(inf);
-    }
-
-    if (!(v_val.is(py::none()))) {
-      cv->value = v_val.cast<double>();
-    }
-
-    if (v_fixed) {
-      cv->fixed = true;
-    } else {
-      cv->fixed = false;
-    }
-
-    if (set_name && !update) {
-      cv->name = symbol_map.attr("getSymbol")(v, labeler).cast<std::string>();
-    }
-
-    if (interval_lb.is(py::none()))
-      cv->domain_lb = -inf;
-    else
-      cv->domain_lb = interval_lb.cast<double>();
-    if (interval_ub.is(py::none()))
-      cv->domain_ub = inf;
-    else
-      cv->domain_ub = interval_ub.cast<double>();
-    if (domain_step == 0)
-      cv->domain = continuous;
-    else if (domain_step == 1) {
-      if ((cv->domain_lb == 0) && (cv->domain_ub == 1))
-        cv->domain = binary;
-      else
-        cv->domain = integers;
-    } else
-      throw py::value_error("Unrecognized domain step");
-
-    if (!update) {
-      var_map[expr_types.id(v)] = py::cast(cv);
-      rev_var_map[py::cast(cv)] = v;
-    }
-  }
-}
+/**___________________________________________________________________________
+ *
+ * Pyomo: Python Optimization Modeling Objects
+ * Copyright (c) 2008-2024
+ * National Technology and Engineering Solutions of Sandia, LLC
+ * Under the terms of Contract DE-NA0003525 with National Technology and
+ * Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+ * rights in this software.
+ * This software is distributed under the 3-clause BSD License.
+ * ___________________________________________________________________________
+**/
+
+#include "expression.hpp"
+
+bool Leaf::is_leaf() { return true; }
+
+bool Var::is_variable_type() { return true; }
+
+bool Param::is_param_type() { return true; }
+
+bool Constant::is_constant_type() { return true; }
+
+bool Expression::is_expression_type() { return true; }
+
+double Leaf::evaluate() { return value; }
+
+double Var::get_lb() {
+  if (fixed)
+    return value;
+  else
+    return std::max(lb->evaluate(), domain_lb);
+}
+
+double Var::get_ub() {
+  if (fixed)
+    return value;
+  else
+    return std::min(ub->evaluate(), domain_ub);
+}
+
+Domain Var::get_domain() { return domain; }
+
+bool Operator::is_operator_type() { return true; }
+
+std::vector<std::shared_ptr<Operator>> Expression::get_operators() {
+  std::vector<std::shared_ptr<Operator>> res(n_operators);
+  for (unsigned int i = 0; i < n_operators; ++i) {
+    res[i] = operators[i];
+  }
+  return res;
+}
+
+double Leaf::get_value_from_array(double *val_array) { return value; }
+
+double Expression::get_value_from_array(double *val_array) {
+  return val_array[n_operators - 1];
+}
+
+double Operator::get_value_from_array(double *val_array) {
+  return val_array[index];
+}
+
+void MultiplyOperator::evaluate(double *values) {
+  values[index] = operand1->get_value_from_array(values) *
+                  operand2->get_value_from_array(values);
+}
+
+void ExternalOperator::evaluate(double *values) {
+  // It would be nice to implement this, but it will take some more work.
+  // This would require dynamic linking to the external function.
+  throw std::runtime_error("cannot evaluate ExternalOperator yet");
+}
+
+void LinearOperator::evaluate(double *values) {
+  values[index] = constant->evaluate();
+  for (unsigned int i = 0; i < nterms; ++i) {
+    values[index] += coefficients[i]->evaluate() * variables[i]->evaluate();
+  }
+}
+
+void SumOperator::evaluate(double *values) {
+  values[index] = 0.0;
+  for (unsigned int i = 0; i < nargs; ++i) {
+    values[index] += operands[i]->get_value_from_array(values);
+  }
+}
+
+void DivideOperator::evaluate(double *values) {
+  values[index] = operand1->get_value_from_array(values) /
+                  operand2->get_value_from_array(values);
+}
+
+void PowerOperator::evaluate(double *values) {
+  values[index] = std::pow(operand1->get_value_from_array(values),
+                           operand2->get_value_from_array(values));
+}
+
+void NegationOperator::evaluate(double *values) {
+  values[index] = -operand->get_value_from_array(values);
+}
+
+void ExpOperator::evaluate(double *values) {
+  values[index] = std::exp(operand->get_value_from_array(values));
+}
+
+void LogOperator::evaluate(double *values) {
+  values[index] = std::log(operand->get_value_from_array(values));
+}
+
+void AbsOperator::evaluate(double *values) {
+  values[index] = std::fabs(operand->get_value_from_array(values));
+}
+
+void SqrtOperator::evaluate(double *values) {
+  values[index] = std::pow(operand->get_value_from_array(values), 0.5);
+}
+
+void Log10Operator::evaluate(double *values) {
+  values[index] = std::log10(operand->get_value_from_array(values));
+}
+
+void SinOperator::evaluate(double *values) {
+  values[index] = std::sin(operand->get_value_from_array(values));
+}
+
+void CosOperator::evaluate(double *values) {
+  values[index] = std::cos(operand->get_value_from_array(values));
+}
+
+void TanOperator::evaluate(double *values) {
+  values[index] = std::tan(operand->get_value_from_array(values));
+}
+
+void AsinOperator::evaluate(double *values) {
+  values[index] = std::asin(operand->get_value_from_array(values));
+}
+
+void AcosOperator::evaluate(double *values) {
+  values[index] = std::acos(operand->get_value_from_array(values));
+}
+
+void AtanOperator::evaluate(double *values) {
+  values[index] = std::atan(operand->get_value_from_array(values));
+}
+
+double Expression::evaluate() {
+  double *values = new double[n_operators];
+  for (unsigned int i = 0; i < n_operators; ++i) {
+    operators[i]->index = i;
+    operators[i]->evaluate(values);
+  }
+  double res = get_value_from_array(values);
+  delete[] values;
+  return res;
+}
+
+void UnaryOperator::identify_variables(
+    std::set<std::shared_ptr<Node>> &var_set,
+    std::shared_ptr<std::vector<std::shared_ptr<Var>>> var_vec) {
+  if (operand->is_variable_type()) {
+    if (var_set.count(operand) == 0) {
+      var_vec->push_back(std::dynamic_pointer_cast<Var>(operand));
+      var_set.insert(operand);
+    }
+  }
+}
+
+void BinaryOperator::identify_variables(
+    std::set<std::shared_ptr<Node>> &var_set,
+    std::shared_ptr<std::vector<std::shared_ptr<Var>>> var_vec) {
+  if (operand1->is_variable_type()) {
+    if (var_set.count(operand1) == 0) {
+      var_vec->push_back(std::dynamic_pointer_cast<Var>(operand1));
+      var_set.insert(operand1);
+    }
+  }
+  if (operand2->is_variable_type()) {
+    if (var_set.count(operand2) == 0) {
+      var_vec->push_back(std::dynamic_pointer_cast<Var>(operand2));
+      var_set.insert(operand2);
+    }
+  }
+}
+
+void ExternalOperator::identify_variables(
+    std::set<std::shared_ptr<Node>> &var_set,
+    std::shared_ptr<std::vector<std::shared_ptr<Var>>> var_vec) {
+  for (unsigned int i = 0; i < nargs; ++i) {
+    if (operands[i]->is_variable_type()) {
+      if (var_set.count(operands[i]) == 0) {
+        var_vec->push_back(std::dynamic_pointer_cast<Var>(operands[i]));
+        var_set.insert(operands[i]);
+      }
+    }
+  }
+}
+
+void LinearOperator::identify_variables(
+    std::set<std::shared_ptr<Node>> &var_set,
+    std::shared_ptr<std::vector<std::shared_ptr<Var>>> var_vec) {
+  for (unsigned int i = 0; i < nterms; ++i) {
+    if (var_set.count(variables[i]) == 0) {
+      var_vec->push_back(std::dynamic_pointer_cast<Var>(variables[i]));
+      var_set.insert(variables[i]);
+    }
+  }
+}
+
+void SumOperator::identify_variables(
+    std::set<std::shared_ptr<Node>> &var_set,
+    std::shared_ptr<std::vector<std::shared_ptr<Var>>> var_vec) {
+  for (unsigned int i = 0; i < nargs; ++i) {
+    if (operands[i]->is_variable_type()) {
+      if (var_set.count(operands[i]) == 0) {
+        var_vec->push_back(std::dynamic_pointer_cast<Var>(operands[i]));
+        var_set.insert(operands[i]);
+      }
+    }
+  }
+}
+
+std::shared_ptr<std::vector<std::shared_ptr<Var>>>
+Expression::identify_variables() {
+  std::set<std::shared_ptr<Node>> var_set;
+  std::shared_ptr<std::vector<std::shared_ptr<Var>>> res =
+      std::make_shared<std::vector<std::shared_ptr<Var>>>(var_set.size());
+  for (unsigned int i = 0; i < n_operators; ++i) {
+    operators[i]->identify_variables(var_set, res);
+  }
+  return res;
+}
+
+std::shared_ptr<std::vector<std::shared_ptr<Var>>> Var::identify_variables() {
+  std::shared_ptr<std::vector<std::shared_ptr<Var>>> res =
+      std::make_shared<std::vector<std::shared_ptr<Var>>>();
+  res->push_back(shared_from_this());
+  return res;
+}
+
+std::shared_ptr<std::vector<std::shared_ptr<Var>>>
+Constant::identify_variables() {
+  std::shared_ptr<std::vector<std::shared_ptr<Var>>> res =
+      std::make_shared<std::vector<std::shared_ptr<Var>>>();
+  return res;
+}
+
+std::shared_ptr<std::vector<std::shared_ptr<Var>>> Param::identify_variables() {
+  std::shared_ptr<std::vector<std::shared_ptr<Var>>> res =
+      std::make_shared<std::vector<std::shared_ptr<Var>>>();
+  return res;
+}
+
+std::shared_ptr<std::vector<std::shared_ptr<ExternalOperator>>>
+Expression::identify_external_operators() {
+  std::set<std::shared_ptr<Node>> external_set;
+  for (unsigned int i = 0; i < n_operators; ++i) {
+    if (operators[i]->is_external_operator()) {
+      external_set.insert(operators[i]);
+    }
+  }
+  std::shared_ptr<std::vector<std::shared_ptr<ExternalOperator>>> res =
+      std::make_shared<std::vector<std::shared_ptr<ExternalOperator>>>(
+          external_set.size());
+  int ndx = 0;
+  for (std::shared_ptr<Node> n : external_set) {
+    (*res)[ndx] = std::dynamic_pointer_cast<ExternalOperator>(n);
+    ndx += 1;
+  }
+  return res;
+}
+
+std::shared_ptr<std::vector<std::shared_ptr<ExternalOperator>>>
+Var::identify_external_operators() {
+  std::shared_ptr<std::vector<std::shared_ptr<ExternalOperator>>> res =
+      std::make_shared<std::vector<std::shared_ptr<ExternalOperator>>>();
+  return res;
+}
+
+std::shared_ptr<std::vector<std::shared_ptr<ExternalOperator>>>
+Constant::identify_external_operators() {
+  std::shared_ptr<std::vector<std::shared_ptr<ExternalOperator>>> res =
+      std::make_shared<std::vector<std::shared_ptr<ExternalOperator>>>();
+  return res;
+}
+
+std::shared_ptr<std::vector<std::shared_ptr<ExternalOperator>>>
+Param::identify_external_operators() {
+  std::shared_ptr<std::vector<std::shared_ptr<ExternalOperator>>> res =
+      std::make_shared<std::vector<std::shared_ptr<ExternalOperator>>>();
+  return res;
+}
+
+int Var::get_degree_from_array(int *degree_array) { return 1; }
+
+int Param::get_degree_from_array(int *degree_array) { return 0; }
+
+int Constant::get_degree_from_array(int *degree_array) { return 0; }
+
+int Expression::get_degree_from_array(int *degree_array) {
+  return degree_array[n_operators - 1];
+}
+
+int Operator::get_degree_from_array(int *degree_array) {
+  return degree_array[index];
+}
+
+void LinearOperator::propagate_degree_forward(int *degrees, double *values) {
+  degrees[index] = 1;
+}
+
+void SumOperator::propagate_degree_forward(int *degrees, double *values) {
+  int deg = 0;
+  int _deg;
+  for (unsigned int i = 0; i < nargs; ++i) {
+    _deg = operands[i]->get_degree_from_array(degrees);
+    if (_deg > deg) {
+      deg = _deg;
+    }
+  }
+  degrees[index] = deg;
+}
+
+void MultiplyOperator::propagate_degree_forward(int *degrees, double *values) {
+  degrees[index] = operand1->get_degree_from_array(degrees) +
+                   operand2->get_degree_from_array(degrees);
+}
+
+void ExternalOperator::propagate_degree_forward(int *degrees, double *values) {
+  // External functions are always considered nonlinear
+  // Anything larger than 2 is nonlinear
+  degrees[index] = 3;
+}
+
+void DivideOperator::propagate_degree_forward(int *degrees, double *values) {
+  // anything larger than 2 is nonlinear
+  degrees[index] = std::max(operand1->get_degree_from_array(degrees),
+                            3 * (operand2->get_degree_from_array(degrees)));
+}
+
+void PowerOperator::propagate_degree_forward(int *degrees, double *values) {
+  if (operand2->get_degree_from_array(degrees) != 0) {
+    degrees[index] = 3;
+  } else {
+    double val2 = operand2->get_value_from_array(values);
+    double intpart;
+    if (std::modf(val2, &intpart) == 0.0) {
+      degrees[index] = operand1->get_degree_from_array(degrees) * (int)val2;
+    } else {
+      degrees[index] = 3;
+    }
+  }
+}
+
+void NegationOperator::propagate_degree_forward(int *degrees, double *values) {
+  degrees[index] = operand->get_degree_from_array(degrees);
+}
+
+void UnaryOperator::propagate_degree_forward(int *degrees, double *values) {
+  if (operand->get_degree_from_array(degrees) == 0) {
+    degrees[index] = 0;
+  } else {
+    degrees[index] = 3;
+  }
+}
+
+std::string Var::__str__() { return name; }
+
+std::string Param::__str__() { return name; }
+
+std::string Constant::__str__() { return std::to_string(value); }
+
+std::string Expression::__str__() {
+  std::string *string_array = new std::string[n_operators];
+  std::shared_ptr<Operator> oper;
+  for (unsigned int i = 0; i < n_operators; ++i) {
+    oper = operators[i];
+    oper->index = i;
+    oper->print(string_array);
+  }
+  std::string res = string_array[n_operators - 1];
+  delete[] string_array;
+  return res;
+}
+
+std::string Leaf::get_string_from_array(std::string *string_array) {
+  return __str__();
+}
+
+std::string Expression::get_string_from_array(std::string *string_array) {
+  return string_array[n_operators - 1];
+}
+
+std::string Operator::get_string_from_array(std::string *string_array) {
+  return string_array[index];
+}
+
+void MultiplyOperator::print(std::string *string_array) {
+  string_array[index] =
+      ("(" + operand1->get_string_from_array(string_array) + "*" +
+       operand2->get_string_from_array(string_array) + ")");
+}
+
+void ExternalOperator::print(std::string *string_array) {
+  std::string res = function_name + "(";
+  for (unsigned int i = 0; i < (nargs - 1); ++i) {
+    res += operands[i]->get_string_from_array(string_array);
+    res += ", ";
+  }
+  res += operands[nargs - 1]->get_string_from_array(string_array);
+  res += ")";
+  string_array[index] = res;
+}
+
+void DivideOperator::print(std::string *string_array) {
+  string_array[index] =
+      ("(" + operand1->get_string_from_array(string_array) + "/" +
+       operand2->get_string_from_array(string_array) + ")");
+}
+
+void PowerOperator::print(std::string *string_array) {
+  string_array[index] =
+      ("(" + operand1->get_string_from_array(string_array) + "**" +
+       operand2->get_string_from_array(string_array) + ")");
+}
+
+void NegationOperator::print(std::string *string_array) {
+  string_array[index] =
+      ("(-" + operand->get_string_from_array(string_array) + ")");
+}
+
+void ExpOperator::print(std::string *string_array) {
+  string_array[index] =
+      ("exp(" + operand->get_string_from_array(string_array) + ")");
+}
+
+void LogOperator::print(std::string *string_array) {
+  string_array[index] =
+      ("log(" + operand->get_string_from_array(string_array) + ")");
+}
+
+void AbsOperator::print(std::string *string_array) {
+  string_array[index] =
+      ("abs(" + operand->get_string_from_array(string_array) + ")");
+}
+
+void SqrtOperator::print(std::string *string_array) {
+  string_array[index] =
+      ("sqrt(" + operand->get_string_from_array(string_array) + ")");
+}
+
+void Log10Operator::print(std::string *string_array) {
+  string_array[index] =
+      ("log10(" + operand->get_string_from_array(string_array) + ")");
+}
+
+void SinOperator::print(std::string *string_array) {
+  string_array[index] =
+      ("sin(" + operand->get_string_from_array(string_array) + ")");
+}
+
+void CosOperator::print(std::string *string_array) {
+  string_array[index] =
+      ("cos(" + operand->get_string_from_array(string_array) + ")");
+}
+
+void TanOperator::print(std::string *string_array) {
+  string_array[index] =
+      ("tan(" + operand->get_string_from_array(string_array) + ")");
+}
+
+void AsinOperator::print(std::string *string_array) {
+  string_array[index] =
+      ("asin(" + operand->get_string_from_array(string_array) + ")");
+}
+
+void AcosOperator::print(std::string *string_array) {
+  string_array[index] =
+      ("acos(" + operand->get_string_from_array(string_array) + ")");
+}
+
+void AtanOperator::print(std::string *string_array) {
+  string_array[index] =
+      ("atan(" + operand->get_string_from_array(string_array) + ")");
+}
+
+void LinearOperator::print(std::string *string_array) {
+  std::string res = "(" + constant->__str__();
+  for (unsigned int i = 0; i < nterms; ++i) {
+    res += " + " + coefficients[i]->__str__() + "*" + variables[i]->__str__();
+  }
+  res += ")";
+  string_array[index] = res;
+}
+
+void SumOperator::print(std::string *string_array) {
+  std::string res = "(" + operands[0]->get_string_from_array(string_array);
+  for (unsigned int i = 1; i < nargs; ++i) {
+    res += " + " + operands[i]->get_string_from_array(string_array);
+  }
+  res += ")";
+  string_array[index] = res;
+}
+
+std::shared_ptr<std::vector<std::shared_ptr<Node>>>
+Leaf::get_prefix_notation() {
+  std::shared_ptr<std::vector<std::shared_ptr<Node>>> res =
+      std::make_shared<std::vector<std::shared_ptr<Node>>>();
+  res->push_back(shared_from_this());
+  return res;
+}
+
+std::shared_ptr<std::vector<std::shared_ptr<Node>>>
+Expression::get_prefix_notation() {
+  std::shared_ptr<std::vector<std::shared_ptr<Node>>> res =
+      std::make_shared<std::vector<std::shared_ptr<Node>>>();
+  std::shared_ptr<std::vector<std::shared_ptr<Node>>> stack =
+      std::make_shared<std::vector<std::shared_ptr<Node>>>();
+  std::shared_ptr<Node> node;
+  stack->push_back(operators[n_operators - 1]);
+  while (stack->size() > 0) {
+    node = stack->back();
+    stack->pop_back();
+    res->push_back(node);
+    node->fill_prefix_notation_stack(stack);
+  }
+
+  return res;
+}
+
+void BinaryOperator::fill_prefix_notation_stack(
+    std::shared_ptr<std::vector<std::shared_ptr<Node>>> stack) {
+  stack->push_back(operand2);
+  stack->push_back(operand1);
+}
+
+void UnaryOperator::fill_prefix_notation_stack(
+    std::shared_ptr<std::vector<std::shared_ptr<Node>>> stack) {
+  stack->push_back(operand);
+}
+
+void SumOperator::fill_prefix_notation_stack(
+    std::shared_ptr<std::vector<std::shared_ptr<Node>>> stack) {
+  int ndx = nargs - 1;
+  while (ndx >= 0) {
+    stack->push_back(operands[ndx]);
+    ndx -= 1;
+  }
+}
+
+void LinearOperator::fill_prefix_notation_stack(
+    std::shared_ptr<std::vector<std::shared_ptr<Node>>> stack) {
+  ; // This is treated as a leaf in this context; write_nl_string will take care
+    // of it
+}
+
+void ExternalOperator::fill_prefix_notation_stack(
+    std::shared_ptr<std::vector<std::shared_ptr<Node>>> stack) {
+  int i = nargs - 1;
+  while (i >= 0) {
+    stack->push_back(operands[i]);
+    i -= 1;
+  }
+}
+
+void Var::write_nl_string(std::ofstream &f) { f << "v" << index << "\n"; }
+
+void Param::write_nl_string(std::ofstream &f) { f << "n" << value << "\n"; }
+
+void Constant::write_nl_string(std::ofstream &f) { f << "n" << value << "\n"; }
+
+void Expression::write_nl_string(std::ofstream &f) {
+  std::shared_ptr<std::vector<std::shared_ptr<Node>>> prefix_notation =
+      get_prefix_notation();
+  for (std::shared_ptr<Node> &node : *(prefix_notation)) {
+    node->write_nl_string(f);
+  }
+}
+
+void MultiplyOperator::write_nl_string(std::ofstream &f) { f << "o2\n"; }
+
+void ExternalOperator::write_nl_string(std::ofstream &f) {
+  f << "f" << external_function_index << " " << nargs << "\n";
+}
+
+void SumOperator::write_nl_string(std::ofstream &f) {
+  if (nargs == 2) {
+    f << "o0\n";
+  } else {
+    f << "o54\n";
+    f << nargs << "\n";
+  }
+}
+
+void LinearOperator::write_nl_string(std::ofstream &f) {
+  bool has_const =
+      (!constant->is_constant_type()) || (constant->evaluate() != 0);
+  unsigned int n_sum_args = nterms + (has_const ? 1 : 0);
+  if (n_sum_args == 2) {
+    f << "o0\n";
+  } else {
+    f << "o54\n";
+    f << n_sum_args << "\n";
+  }
+  if (has_const)
+    f << "n" << constant->evaluate() << "\n";
+  for (unsigned int ndx = 0; ndx < nterms; ++ndx) {
+    f << "o2\n";
+    f << "n" << coefficients[ndx]->evaluate() << "\n";
+    variables[ndx]->write_nl_string(f);
+  }
+}
+
+void DivideOperator::write_nl_string(std::ofstream &f) { f << "o3\n"; }
+
+void PowerOperator::write_nl_string(std::ofstream &f) { f << "o5\n"; }
+
+void NegationOperator::write_nl_string(std::ofstream &f) { f << "o16\n"; }
+
+void ExpOperator::write_nl_string(std::ofstream &f) { f << "o44\n"; }
+
+void LogOperator::write_nl_string(std::ofstream &f) { f << "o43\n"; }
+
+void AbsOperator::write_nl_string(std::ofstream &f) { f << "o15\n"; }
+
+void SqrtOperator::write_nl_string(std::ofstream &f) { f << "o39\n"; }
+
+void Log10Operator::write_nl_string(std::ofstream &f) { f << "o42\n"; }
+
+void SinOperator::write_nl_string(std::ofstream &f) { f << "o41\n"; }
+
+void CosOperator::write_nl_string(std::ofstream &f) { f << "o46\n"; }
+
+void TanOperator::write_nl_string(std::ofstream &f) { f << "o38\n"; }
+
+void AsinOperator::write_nl_string(std::ofstream &f) { f << "o51\n"; }
+
+void AcosOperator::write_nl_string(std::ofstream &f) { f << "o53\n"; }
+
+void AtanOperator::write_nl_string(std::ofstream &f) { f << "o49\n"; }
+
+bool BinaryOperator::is_binary_operator() { return true; }
+
+bool UnaryOperator::is_unary_operator() { return true; }
+
+bool LinearOperator::is_linear_operator() { return true; }
+
+bool SumOperator::is_sum_operator() { return true; }
+
+bool MultiplyOperator::is_multiply_operator() { return true; }
+
+bool DivideOperator::is_divide_operator() { return true; }
+
+bool PowerOperator::is_power_operator() { return true; }
+
+bool NegationOperator::is_negation_operator() { return true; }
+
+bool ExpOperator::is_exp_operator() { return true; }
+
+bool LogOperator::is_log_operator() { return true; }
+
+bool AbsOperator::is_abs_operator() { return true; }
+
+bool SqrtOperator::is_sqrt_operator() { return true; }
+
+bool ExternalOperator::is_external_operator() { return true; }
+
+void Leaf::fill_expression(std::shared_ptr<Operator> *oper_array,
+                           int &oper_ndx) {
+  ;
+}
+
+void Expression::fill_expression(std::shared_ptr<Operator> *oper_array,
+                                 int &oper_ndx) {
+  throw std::runtime_error("This should not happen");
+}
+
+void BinaryOperator::fill_expression(std::shared_ptr<Operator> *oper_array,
+                                     int &oper_ndx) {
+  oper_ndx -= 1;
+  oper_array[oper_ndx] = shared_from_this();
+  // The order does not actually matter here. It
+  // will just be easier to debug this way.
+  operand2->fill_expression(oper_array, oper_ndx);
+  operand1->fill_expression(oper_array, oper_ndx);
+}
+
+void UnaryOperator::fill_expression(std::shared_ptr<Operator> *oper_array,
+                                    int &oper_ndx) {
+  oper_ndx -= 1;
+  oper_array[oper_ndx] = shared_from_this();
+  operand->fill_expression(oper_array, oper_ndx);
+}
+
+void LinearOperator::fill_expression(std::shared_ptr<Operator> *oper_array,
+                                     int &oper_ndx) {
+  oper_ndx -= 1;
+  oper_array[oper_ndx] = shared_from_this();
+}
+
+void SumOperator::fill_expression(std::shared_ptr<Operator> *oper_array,
+                                  int &oper_ndx) {
+  oper_ndx -= 1;
+  oper_array[oper_ndx] = shared_from_this();
+  // The order does not actually matter here. It
+  // will just be easier to debug this way.
+  int arg_ndx = nargs - 1;
+  while (arg_ndx >= 0) {
+    operands[arg_ndx]->fill_expression(oper_array, oper_ndx);
+    arg_ndx -= 1;
+  }
+}
+
+void ExternalOperator::fill_expression(std::shared_ptr<Operator> *oper_array,
+                                       int &oper_ndx) {
+  oper_ndx -= 1;
+  oper_array[oper_ndx] = shared_from_this();
+  // The order does not actually matter here. It
+  // will just be easier to debug this way.
+  int arg_ndx = nargs - 1;
+  while (arg_ndx >= 0) {
+    operands[arg_ndx]->fill_expression(oper_array, oper_ndx);
+    arg_ndx -= 1;
+  }
+}
+
+double Leaf::get_lb_from_array(double *lbs) { return value; }
+
+double Leaf::get_ub_from_array(double *ubs) { return value; }
+
+double Var::get_lb_from_array(double *lbs) { return get_lb(); }
+
+double Var::get_ub_from_array(double *ubs) { return get_ub(); }
+
+double Expression::get_lb_from_array(double *lbs) {
+  return lbs[n_operators - 1];
+}
+
+double Expression::get_ub_from_array(double *ubs) {
+  return ubs[n_operators - 1];
+}
+
+double Operator::get_lb_from_array(double *lbs) { return lbs[index]; }
+
+double Operator::get_ub_from_array(double *ubs) { return ubs[index]; }
+
+void Leaf::set_bounds_in_array(double new_lb, double new_ub, double *lbs,
+                               double *ubs, double feasibility_tol,
+                               double integer_tol, double improvement_tol,
+                               std::set<std::shared_ptr<Var>> &improved_vars) {
+  if (new_lb < value - feasibility_tol || new_lb > value + feasibility_tol) {
+    throw InfeasibleConstraintException(
+        "Infeasible constraint; bounds computed on parameter or constant "
+        "disagree with the value of the parameter or constant\n  value: " +
+        std::to_string(value) + "\n  computed LB: " + std::to_string(new_lb) +
+        "\n computed UB: " + std::to_string(new_ub));
+  }
+
+  if (new_ub < value - feasibility_tol || new_ub > value + feasibility_tol) {
+    throw InfeasibleConstraintException(
+        "Infeasible constraint; bounds computed on parameter or constant "
+        "disagree with the value of the parameter or constant\n  value: " +
+        std::to_string(value) + "\n  computed LB: " + std::to_string(new_lb) +
+        "\n computed UB: " + std::to_string(new_ub));
+  }
+}
+
+void Var::set_bounds_in_array(double new_lb, double new_ub, double *lbs,
+                              double *ubs, double feasibility_tol,
+                              double integer_tol, double improvement_tol,
+                              std::set<std::shared_ptr<Var>> &improved_vars) {
+  if (new_lb > new_ub) {
+    if (new_lb - feasibility_tol > new_ub)
+      throw InfeasibleConstraintException(
+          "Infeasible constraint; The computed lower bound for a variable is "
+          "larger than the computed upper bound.\n  computed LB: " +
+          std::to_string(new_lb) +
+          "\n  computed UB: " + std::to_string(new_ub));
+    else {
+      new_lb -= feasibility_tol;
+      new_ub += feasibility_tol;
+    }
+  }
+  if (new_lb >= inf)
+    throw InfeasibleConstraintException(
+        "Infeasible constraint; The compute lower bound for " + name +
+        " is inf");
+  if (new_ub <= -inf)
+    throw InfeasibleConstraintException(
+        "Infeasible constraint; The computed upper bound for " + name +
+        " is -inf");
+
+  if (domain == integers || domain == binary) {
+    if (new_lb > -inf) {
+      double lb_floor = floor(new_lb);
+      double lb_ceil = ceil(new_lb - integer_tol);
+      if (lb_floor > lb_ceil)
+        new_lb = lb_floor;
+      else
+        new_lb = lb_ceil;
+    }
+    if (new_ub < inf) {
+      double ub_ceil = ceil(new_ub);
+      double ub_floor = floor(new_ub + integer_tol);
+      if (ub_ceil < ub_floor)
+        new_ub = ub_ceil;
+      else
+        new_ub = ub_floor;
+    }
+  }
+
+  double current_lb = get_lb();
+  double current_ub = get_ub();
+
+  if (new_lb > current_lb + improvement_tol ||
+      new_ub < current_ub - improvement_tol)
+    improved_vars.insert(shared_from_this());
+
+  if (new_lb > current_lb) {
+    if (lb->is_leaf())
+      std::dynamic_pointer_cast<Leaf>(lb)->value = new_lb;
+    else
+      throw py::value_error(
+          "variable bounds cannot be expressions when performing FBBT");
+  }
+
+  if (new_ub < current_ub) {
+    if (ub->is_leaf())
+      std::dynamic_pointer_cast<Leaf>(ub)->value = new_ub;
+    else
+      throw py::value_error(
+          "variable bounds cannot be expressions when performing FBBT");
+  }
+}
+
+void Expression::set_bounds_in_array(
+    double new_lb, double new_ub, double *lbs, double *ubs,
+    double feasibility_tol, double integer_tol, double improvement_tol,
+    std::set<std::shared_ptr<Var>> &improved_vars) {
+  lbs[n_operators - 1] = new_lb;
+  ubs[n_operators - 1] = new_ub;
+}
+
+void Operator::set_bounds_in_array(
+    double new_lb, double new_ub, double *lbs, double *ubs,
+    double feasibility_tol, double integer_tol, double improvement_tol,
+    std::set<std::shared_ptr<Var>> &improved_vars) {
+  lbs[index] = new_lb;
+  ubs[index] = new_ub;
+}
+
+void Expression::propagate_bounds_forward(double *lbs, double *ubs,
+                                          double feasibility_tol,
+                                          double integer_tol) {
+  for (unsigned int ndx = 0; ndx < n_operators; ++ndx) {
+    operators[ndx]->index = ndx;
+    operators[ndx]->propagate_bounds_forward(lbs, ubs, feasibility_tol,
+                                             integer_tol);
+  }
+}
+
+void Expression::propagate_bounds_backward(
+    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
+  int ndx = n_operators - 1;
+  while (ndx >= 0) {
+    operators[ndx]->propagate_bounds_backward(
+        lbs, ubs, feasibility_tol, integer_tol, improvement_tol, improved_vars);
+    ndx -= 1;
+  }
+}
+
+void Operator::propagate_bounds_forward(double *lbs, double *ubs,
+                                        double feasibility_tol,
+                                        double integer_tol) {
+  lbs[index] = -inf;
+  ubs[index] = inf;
+}
+
+void Operator::propagate_bounds_backward(
+    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
+  ;
+}
+
+void MultiplyOperator::propagate_bounds_forward(double *lbs, double *ubs,
+                                                double feasibility_tol,
+                                                double integer_tol) {
+  if (operand1 == operand2) {
+    interval_power(operand1->get_lb_from_array(lbs),
+                   operand1->get_ub_from_array(ubs), 2, 2, &lbs[index],
+                   &ubs[index], feasibility_tol);
+  } else {
+    interval_mul(operand1->get_lb_from_array(lbs),
+                 operand1->get_ub_from_array(ubs),
+                 operand2->get_lb_from_array(lbs),
+                 operand2->get_ub_from_array(ubs), &lbs[index], &ubs[index]);
+  }
+}
+
+void MultiplyOperator::propagate_bounds_backward(
+    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
+  double xl = operand1->get_lb_from_array(lbs);
+  double xu = operand1->get_ub_from_array(ubs);
+  double yl = operand2->get_lb_from_array(lbs);
+  double yu = operand2->get_ub_from_array(ubs);
+  double lb = get_lb_from_array(lbs);
+  double ub = get_ub_from_array(ubs);
+
+  double new_xl, new_xu, new_yl, new_yu;
+
+  if (operand1 == operand2) {
+    _inverse_power1(lb, ub, 2, 2, xl, xu, &new_xl, &new_xu, feasibility_tol);
+    new_yl = new_xl;
+    new_yu = new_xu;
+  } else {
+    interval_div(lb, ub, yl, yu, &new_xl, &new_xu, feasibility_tol);
+    interval_div(lb, ub, xl, xu, &new_yl, &new_yu, feasibility_tol);
+  }
+
+  if (new_xl > xl)
+    xl = new_xl;
+  if (new_xu < xu)
+    xu = new_xu;
+  operand1->set_bounds_in_array(xl, xu, lbs, ubs, feasibility_tol, integer_tol,
+                                improvement_tol, improved_vars);
+
+  if (new_yl > yl)
+    yl = new_yl;
+  if (new_yu < yu)
+    yu = new_yu;
+  operand2->set_bounds_in_array(yl, yu, lbs, ubs, feasibility_tol, integer_tol,
+                                improvement_tol, improved_vars);
+}
+
+void SumOperator::propagate_bounds_forward(double *lbs, double *ubs,
+                                           double feasibility_tol,
+                                           double integer_tol) {
+  double lb = operands[0]->get_lb_from_array(lbs);
+  double ub = operands[0]->get_ub_from_array(ubs);
+  double tmp_lb;
+  double tmp_ub;
+
+  for (unsigned int ndx = 1; ndx < nargs; ++ndx) {
+    interval_add(lb, ub, operands[ndx]->get_lb_from_array(lbs),
+                 operands[ndx]->get_ub_from_array(ubs), &tmp_lb, &tmp_ub);
+    lb = tmp_lb;
+    ub = tmp_ub;
+  }
+
+  lbs[index] = lb;
+  ubs[index] = ub;
+}
+
+void SumOperator::propagate_bounds_backward(
+    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
+  double *accumulated_lbs = new double[nargs];
+  double *accumulated_ubs = new double[nargs];
+
+  accumulated_lbs[0] = operands[0]->get_lb_from_array(lbs);
+  accumulated_ubs[0] = operands[0]->get_ub_from_array(ubs);
+  for (unsigned int ndx = 1; ndx < nargs; ++ndx) {
+    interval_add(accumulated_lbs[ndx - 1], accumulated_ubs[ndx - 1],
+                 operands[ndx]->get_lb_from_array(lbs),
+                 operands[ndx]->get_ub_from_array(ubs), &accumulated_lbs[ndx],
+                 &accumulated_ubs[ndx]);
+  }
+
+  double new_sum_lb = get_lb_from_array(lbs);
+  double new_sum_ub = get_ub_from_array(ubs);
+
+  if (new_sum_lb > accumulated_lbs[nargs - 1])
+    accumulated_lbs[nargs - 1] = new_sum_lb;
+  if (new_sum_ub < accumulated_ubs[nargs - 1])
+    accumulated_ubs[nargs - 1] = new_sum_ub;
+
+  double lb0, ub0, lb1, ub1, lb2, ub2, _lb1, _ub1, _lb2, _ub2;
+
+  int ndx = nargs - 1;
+  while (ndx >= 1) {
+    lb0 = accumulated_lbs[ndx];
+    ub0 = accumulated_ubs[ndx];
+    lb1 = accumulated_lbs[ndx - 1];
+    ub1 = accumulated_ubs[ndx - 1];
+    lb2 = operands[ndx]->get_lb_from_array(lbs);
+    ub2 = operands[ndx]->get_ub_from_array(ubs);
+    interval_sub(lb0, ub0, lb2, ub2, &_lb1, &_ub1);
+    interval_sub(lb0, ub0, lb1, ub1, &_lb2, &_ub2);
+    if (_lb1 > lb1)
+      lb1 = _lb1;
+    if (_ub1 < ub1)
+      ub1 = _ub1;
+    if (_lb2 > lb2)
+      lb2 = _lb2;
+    if (_ub2 < ub2)
+      ub2 = _ub2;
+    accumulated_lbs[ndx - 1] = lb1;
+    accumulated_ubs[ndx - 1] = ub1;
+    operands[ndx]->set_bounds_in_array(lb2, ub2, lbs, ubs, feasibility_tol,
+                                       integer_tol, improvement_tol,
+                                       improved_vars);
+    ndx -= 1;
+  }
+
+  // take care of ndx = 0
+  lb1 = operands[0]->get_lb_from_array(lbs);
+  ub1 = operands[0]->get_ub_from_array(ubs);
+  _lb1 = accumulated_lbs[0];
+  _ub1 = accumulated_ubs[0];
+  if (_lb1 > lb1)
+    lb1 = _lb1;
+  if (_ub1 < ub1)
+    ub1 = _ub1;
+  operands[0]->set_bounds_in_array(lb1, ub1, lbs, ubs, feasibility_tol,
+                                   integer_tol, improvement_tol, improved_vars);
+
+  delete[] accumulated_lbs;
+  delete[] accumulated_ubs;
+}
+
+void LinearOperator::propagate_bounds_forward(double *lbs, double *ubs,
+                                              double feasibility_tol,
+                                              double integer_tol) {
+  double lb = constant->evaluate();
+  double ub = lb;
+  double tmp_lb;
+  double tmp_ub;
+  double coef;
+
+  for (unsigned int ndx = 0; ndx < nterms; ++ndx) {
+    coef = coefficients[ndx]->evaluate();
+    interval_mul(coef, coef, variables[ndx]->get_lb(), variables[ndx]->get_ub(),
+                 &tmp_lb, &tmp_ub);
+    interval_add(lb, ub, tmp_lb, tmp_ub, &lb, &ub);
+  }
+
+  lbs[index] = lb;
+  ubs[index] = ub;
+}
+
+void LinearOperator::propagate_bounds_backward(
+    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
+  double *accumulated_lbs = new double[nterms + 1];
+  double *accumulated_ubs = new double[nterms + 1];
+
+  double coef;
+
+  accumulated_lbs[0] = constant->evaluate();
+  accumulated_ubs[0] = constant->evaluate();
+  for (unsigned int ndx = 0; ndx < nterms; ++ndx) {
+    coef = coefficients[ndx]->evaluate();
+    interval_mul(coef, coef, variables[ndx]->get_lb(), variables[ndx]->get_ub(),
+                 &accumulated_lbs[ndx + 1], &accumulated_ubs[ndx + 1]);
+    interval_add(accumulated_lbs[ndx], accumulated_ubs[ndx],
+                 accumulated_lbs[ndx + 1], accumulated_ubs[ndx + 1],
+                 &accumulated_lbs[ndx + 1], &accumulated_ubs[ndx + 1]);
+  }
+
+  double new_sum_lb = get_lb_from_array(lbs);
+  double new_sum_ub = get_ub_from_array(ubs);
+
+  if (new_sum_lb > accumulated_lbs[nterms])
+    accumulated_lbs[nterms] = new_sum_lb;
+  if (new_sum_ub < accumulated_ubs[nterms])
+    accumulated_ubs[nterms] = new_sum_ub;
+
+  double lb0, ub0, lb1, ub1, lb2, ub2, _lb1, _ub1, _lb2, _ub2, new_v_lb,
+      new_v_ub;
+
+  int ndx = nterms - 1;
+  while (ndx >= 0) {
+    lb0 = accumulated_lbs[ndx + 1];
+    ub0 = accumulated_ubs[ndx + 1];
+    lb1 = accumulated_lbs[ndx];
+    ub1 = accumulated_ubs[ndx];
+    coef = coefficients[ndx]->evaluate();
+    interval_mul(coef, coef, variables[ndx]->get_lb(), variables[ndx]->get_ub(),
+                 &lb2, &ub2);
+    interval_sub(lb0, ub0, lb2, ub2, &_lb1, &_ub1);
+    interval_sub(lb0, ub0, lb1, ub1, &_lb2, &_ub2);
+    if (_lb1 > lb1)
+      lb1 = _lb1;
+    if (_ub1 < ub1)
+      ub1 = _ub1;
+    if (_lb2 > lb2)
+      lb2 = _lb2;
+    if (_ub2 < ub2)
+      ub2 = _ub2;
+    accumulated_lbs[ndx] = lb1;
+    accumulated_ubs[ndx] = ub1;
+    interval_div(lb2, ub2, coef, coef, &new_v_lb, &new_v_ub, feasibility_tol);
+    variables[ndx]->set_bounds_in_array(new_v_lb, new_v_ub, lbs, ubs,
+                                        feasibility_tol, integer_tol,
+                                        improvement_tol, improved_vars);
+    ndx -= 1;
+  }
+
+  delete[] accumulated_lbs;
+  delete[] accumulated_ubs;
+}
+
+void DivideOperator::propagate_bounds_forward(double *lbs, double *ubs,
+                                              double feasibility_tol,
+                                              double integer_tol) {
+  interval_div(
+      operand1->get_lb_from_array(lbs), operand1->get_ub_from_array(ubs),
+      operand2->get_lb_from_array(lbs), operand2->get_ub_from_array(ubs),
+      &lbs[index], &ubs[index], feasibility_tol);
+}
+
+void DivideOperator::propagate_bounds_backward(
+    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
+  double xl = operand1->get_lb_from_array(lbs);
+  double xu = operand1->get_ub_from_array(ubs);
+  double yl = operand2->get_lb_from_array(lbs);
+  double yu = operand2->get_ub_from_array(ubs);
+  double lb = get_lb_from_array(lbs);
+  double ub = get_ub_from_array(ubs);
+
+  double new_xl;
+  double new_xu;
+  double new_yl;
+  double new_yu;
+
+  interval_mul(lb, ub, yl, yu, &new_xl, &new_xu);
+  interval_div(xl, xu, lb, ub, &new_yl, &new_yu, feasibility_tol);
+
+  if (new_xl > xl)
+    xl = new_xl;
+  if (new_xu < xu)
+    xu = new_xu;
+  operand1->set_bounds_in_array(xl, xu, lbs, ubs, feasibility_tol, integer_tol,
+                                improvement_tol, improved_vars);
+
+  if (new_yl > yl)
+    yl = new_yl;
+  if (new_yu < yu)
+    yu = new_yu;
+  operand2->set_bounds_in_array(yl, yu, lbs, ubs, feasibility_tol, integer_tol,
+                                improvement_tol, improved_vars);
+}
+
+void NegationOperator::propagate_bounds_forward(double *lbs, double *ubs,
+                                                double feasibility_tol,
+                                                double integer_tol) {
+  interval_sub(0, 0, operand->get_lb_from_array(lbs),
+               operand->get_ub_from_array(ubs), &lbs[index], &ubs[index]);
+}
+
+void NegationOperator::propagate_bounds_backward(
+    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
+  double xl = operand->get_lb_from_array(lbs);
+  double xu = operand->get_ub_from_array(ubs);
+  double lb = get_lb_from_array(lbs);
+  double ub = get_ub_from_array(ubs);
+
+  double new_xl;
+  double new_xu;
+
+  interval_sub(0, 0, lb, ub, &new_xl, &new_xu);
+
+  if (new_xl > xl)
+    xl = new_xl;
+  if (new_xu < xu)
+    xu = new_xu;
+  operand->set_bounds_in_array(xl, xu, lbs, ubs, feasibility_tol, integer_tol,
+                               improvement_tol, improved_vars);
+}
+
+void PowerOperator::propagate_bounds_forward(double *lbs, double *ubs,
+                                             double feasibility_tol,
+                                             double integer_tol) {
+  interval_power(
+      operand1->get_lb_from_array(lbs), operand1->get_ub_from_array(ubs),
+      operand2->get_lb_from_array(lbs), operand2->get_ub_from_array(ubs),
+      &lbs[index], &ubs[index], feasibility_tol);
+}
+
+void PowerOperator::propagate_bounds_backward(
+    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
+  double xl = operand1->get_lb_from_array(lbs);
+  double xu = operand1->get_ub_from_array(ubs);
+  double yl = operand2->get_lb_from_array(lbs);
+  double yu = operand2->get_ub_from_array(ubs);
+  double lb = get_lb_from_array(lbs);
+  double ub = get_ub_from_array(ubs);
+
+  double new_xl, new_xu, new_yl, new_yu;
+  _inverse_power1(lb, ub, yl, yu, xl, xu, &new_xl, &new_xu, feasibility_tol);
+  if (yl != yu)
+    _inverse_power2(lb, ub, xl, xu, &new_yl, &new_yu, feasibility_tol);
+  else {
+    new_yl = yl;
+    new_yu = yu;
+  }
+
+  if (new_xl > xl)
+    xl = new_xl;
+  if (new_xu < xu)
+    xu = new_xu;
+  operand1->set_bounds_in_array(xl, xu, lbs, ubs, feasibility_tol, integer_tol,
+                                improvement_tol, improved_vars);
+
+  if (new_yl > yl)
+    yl = new_yl;
+  if (new_yu < yu)
+    yu = new_yu;
+  operand2->set_bounds_in_array(yl, yu, lbs, ubs, feasibility_tol, integer_tol,
+                                improvement_tol, improved_vars);
+}
+
+void SqrtOperator::propagate_bounds_forward(double *lbs, double *ubs,
+                                            double feasibility_tol,
+                                            double integer_tol) {
+  interval_power(operand->get_lb_from_array(lbs),
+                 operand->get_ub_from_array(ubs), 0.5, 0.5, &lbs[index],
+                 &ubs[index], feasibility_tol);
+}
+
+void SqrtOperator::propagate_bounds_backward(
+    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
+  double xl = operand->get_lb_from_array(lbs);
+  double xu = operand->get_ub_from_array(ubs);
+  double yl = 0.5;
+  double yu = 0.5;
+  double lb = get_lb_from_array(lbs);
+  double ub = get_ub_from_array(ubs);
+
+  double new_xl, new_xu;
+  _inverse_power1(lb, ub, yl, yu, xl, xu, &new_xl, &new_xu, feasibility_tol);
+
+  if (new_xl > xl)
+    xl = new_xl;
+  if (new_xu < xu)
+    xu = new_xu;
+  operand->set_bounds_in_array(xl, xu, lbs, ubs, feasibility_tol, integer_tol,
+                               improvement_tol, improved_vars);
+}
+
+void ExpOperator::propagate_bounds_forward(double *lbs, double *ubs,
+                                           double feasibility_tol,
+                                           double integer_tol) {
+  interval_exp(operand->get_lb_from_array(lbs), operand->get_ub_from_array(ubs),
+               &lbs[index], &ubs[index]);
+}
+
+void ExpOperator::propagate_bounds_backward(
+    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
+  double xl = operand->get_lb_from_array(lbs);
+  double xu = operand->get_ub_from_array(ubs);
+  double lb = get_lb_from_array(lbs);
+  double ub = get_ub_from_array(ubs);
+
+  double new_xl, new_xu;
+  interval_log(lb, ub, &new_xl, &new_xu);
+
+  if (new_xl > xl)
+    xl = new_xl;
+  if (new_xu < xu)
+    xu = new_xu;
+  operand->set_bounds_in_array(xl, xu, lbs, ubs, feasibility_tol, integer_tol,
+                               improvement_tol, improved_vars);
+}
+
+void LogOperator::propagate_bounds_forward(double *lbs, double *ubs,
+                                           double feasibility_tol,
+                                           double integer_tol) {
+  interval_log(operand->get_lb_from_array(lbs), operand->get_ub_from_array(ubs),
+               &lbs[index], &ubs[index]);
+}
+
+void LogOperator::propagate_bounds_backward(
+    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
+  double xl = operand->get_lb_from_array(lbs);
+  double xu = operand->get_ub_from_array(ubs);
+  double lb = get_lb_from_array(lbs);
+  double ub = get_ub_from_array(ubs);
+
+  double new_xl, new_xu;
+  interval_exp(lb, ub, &new_xl, &new_xu);
+
+  if (new_xl > xl)
+    xl = new_xl;
+  if (new_xu < xu)
+    xu = new_xu;
+  operand->set_bounds_in_array(xl, xu, lbs, ubs, feasibility_tol, integer_tol,
+                               improvement_tol, improved_vars);
+}
+
+void AbsOperator::propagate_bounds_forward(double *lbs, double *ubs,
+                                           double feasibility_tol,
+                                           double integer_tol) {
+  interval_abs(operand->get_lb_from_array(lbs), operand->get_ub_from_array(ubs),
+               &lbs[index], &ubs[index]);
+}
+
+void AbsOperator::propagate_bounds_backward(
+    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
+  double xl = operand->get_lb_from_array(lbs);
+  double xu = operand->get_ub_from_array(ubs);
+  double lb = get_lb_from_array(lbs);
+  double ub = get_ub_from_array(ubs);
+
+  double new_xl, new_xu;
+  _inverse_abs(lb, ub, &new_xl, &new_xu);
+
+  if (new_xl > xl)
+    xl = new_xl;
+  if (new_xu < xu)
+    xu = new_xu;
+  operand->set_bounds_in_array(xl, xu, lbs, ubs, feasibility_tol, integer_tol,
+                               improvement_tol, improved_vars);
+}
+
+void Log10Operator::propagate_bounds_forward(double *lbs, double *ubs,
+                                             double feasibility_tol,
+                                             double integer_tol) {
+  interval_log10(operand->get_lb_from_array(lbs),
+                 operand->get_ub_from_array(ubs), &lbs[index], &ubs[index]);
+}
+
+void Log10Operator::propagate_bounds_backward(
+    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
+  double xl = operand->get_lb_from_array(lbs);
+  double xu = operand->get_ub_from_array(ubs);
+  double lb = get_lb_from_array(lbs);
+  double ub = get_ub_from_array(ubs);
+
+  double new_xl, new_xu;
+  interval_power(10, 10, lb, ub, &new_xl, &new_xu, feasibility_tol);
+
+  if (new_xl > xl)
+    xl = new_xl;
+  if (new_xu < xu)
+    xu = new_xu;
+  operand->set_bounds_in_array(xl, xu, lbs, ubs, feasibility_tol, integer_tol,
+                               improvement_tol, improved_vars);
+}
+
+void SinOperator::propagate_bounds_forward(double *lbs, double *ubs,
+                                           double feasibility_tol,
+                                           double integer_tol) {
+  interval_sin(operand->get_lb_from_array(lbs), operand->get_ub_from_array(ubs),
+               &lbs[index], &ubs[index]);
+}
+
+void SinOperator::propagate_bounds_backward(
+    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
+  double xl = operand->get_lb_from_array(lbs);
+  double xu = operand->get_ub_from_array(ubs);
+  double lb = get_lb_from_array(lbs);
+  double ub = get_ub_from_array(ubs);
+
+  double new_xl, new_xu;
+  interval_asin(lb, ub, xl, xu, &new_xl, &new_xu, feasibility_tol);
+
+  if (new_xl > xl)
+    xl = new_xl;
+  if (new_xu < xu)
+    xu = new_xu;
+  operand->set_bounds_in_array(xl, xu, lbs, ubs, feasibility_tol, integer_tol,
+                               improvement_tol, improved_vars);
+}
+
+void CosOperator::propagate_bounds_forward(double *lbs, double *ubs,
+                                           double feasibility_tol,
+                                           double integer_tol) {
+  interval_cos(operand->get_lb_from_array(lbs), operand->get_ub_from_array(ubs),
+               &lbs[index], &ubs[index]);
+}
+
+void CosOperator::propagate_bounds_backward(
+    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
+  double xl = operand->get_lb_from_array(lbs);
+  double xu = operand->get_ub_from_array(ubs);
+  double lb = get_lb_from_array(lbs);
+  double ub = get_ub_from_array(ubs);
+
+  double new_xl, new_xu;
+  interval_acos(lb, ub, xl, xu, &new_xl, &new_xu, feasibility_tol);
+
+  if (new_xl > xl)
+    xl = new_xl;
+  if (new_xu < xu)
+    xu = new_xu;
+  operand->set_bounds_in_array(xl, xu, lbs, ubs, feasibility_tol, integer_tol,
+                               improvement_tol, improved_vars);
+}
+
+void TanOperator::propagate_bounds_forward(double *lbs, double *ubs,
+                                           double feasibility_tol,
+                                           double integer_tol) {
+  interval_tan(operand->get_lb_from_array(lbs), operand->get_ub_from_array(ubs),
+               &lbs[index], &ubs[index]);
+}
+
+void TanOperator::propagate_bounds_backward(
+    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
+  double xl = operand->get_lb_from_array(lbs);
+  double xu = operand->get_ub_from_array(ubs);
+  double lb = get_lb_from_array(lbs);
+  double ub = get_ub_from_array(ubs);
+
+  double new_xl, new_xu;
+  interval_atan(lb, ub, xl, xu, &new_xl, &new_xu);
+
+  if (new_xl > xl)
+    xl = new_xl;
+  if (new_xu < xu)
+    xu = new_xu;
+  operand->set_bounds_in_array(xl, xu, lbs, ubs, feasibility_tol, integer_tol,
+                               improvement_tol, improved_vars);
+}
+
+void AsinOperator::propagate_bounds_forward(double *lbs, double *ubs,
+                                            double feasibility_tol,
+                                            double integer_tol) {
+  interval_asin(operand->get_lb_from_array(lbs),
+                operand->get_ub_from_array(ubs), -inf, inf, &lbs[index],
+                &ubs[index], feasibility_tol);
+}
+
+void AsinOperator::propagate_bounds_backward(
+    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
+  double xl = operand->get_lb_from_array(lbs);
+  double xu = operand->get_ub_from_array(ubs);
+  double lb = get_lb_from_array(lbs);
+  double ub = get_ub_from_array(ubs);
+
+  double new_xl, new_xu;
+  interval_sin(lb, ub, &new_xl, &new_xu);
+
+  if (new_xl > xl)
+    xl = new_xl;
+  if (new_xu < xu)
+    xu = new_xu;
+  operand->set_bounds_in_array(xl, xu, lbs, ubs, feasibility_tol, integer_tol,
+                               improvement_tol, improved_vars);
+}
+
+void AcosOperator::propagate_bounds_forward(double *lbs, double *ubs,
+                                            double feasibility_tol,
+                                            double integer_tol) {
+  interval_acos(operand->get_lb_from_array(lbs),
+                operand->get_ub_from_array(ubs), -inf, inf, &lbs[index],
+                &ubs[index], feasibility_tol);
+}
+
+void AcosOperator::propagate_bounds_backward(
+    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
+  double xl = operand->get_lb_from_array(lbs);
+  double xu = operand->get_ub_from_array(ubs);
+  double lb = get_lb_from_array(lbs);
+  double ub = get_ub_from_array(ubs);
+
+  double new_xl, new_xu;
+  interval_cos(lb, ub, &new_xl, &new_xu);
+
+  if (new_xl > xl)
+    xl = new_xl;
+  if (new_xu < xu)
+    xu = new_xu;
+  operand->set_bounds_in_array(xl, xu, lbs, ubs, feasibility_tol, integer_tol,
+                               improvement_tol, improved_vars);
+}
+
+void AtanOperator::propagate_bounds_forward(double *lbs, double *ubs,
+                                            double feasibility_tol,
+                                            double integer_tol) {
+  interval_atan(operand->get_lb_from_array(lbs),
+                operand->get_ub_from_array(ubs), -inf, inf, &lbs[index],
+                &ubs[index]);
+}
+
+void AtanOperator::propagate_bounds_backward(
+    double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+    double improvement_tol, std::set<std::shared_ptr<Var>> &improved_vars) {
+  double xl = operand->get_lb_from_array(lbs);
+  double xu = operand->get_ub_from_array(ubs);
+  double lb = get_lb_from_array(lbs);
+  double ub = get_ub_from_array(ubs);
+
+  double new_xl, new_xu;
+  interval_tan(lb, ub, &new_xl, &new_xu);
+
+  if (new_xl > xl)
+    xl = new_xl;
+  if (new_xu < xu)
+    xu = new_xu;
+  operand->set_bounds_in_array(xl, xu, lbs, ubs, feasibility_tol, integer_tol,
+                               improvement_tol, improved_vars);
+}
+
+std::vector<std::shared_ptr<Var>> create_vars(int n_vars) {
+  std::vector<std::shared_ptr<Var>> res;
+  for (int i = 0; i < n_vars; ++i) {
+    res.push_back(std::make_shared<Var>());
+  }
+  return res;
+}
+
+std::vector<std::shared_ptr<Param>> create_params(int n_params) {
+  std::vector<std::shared_ptr<Param>> res;
+  for (int i = 0; i < n_params; ++i) {
+    res.push_back(std::make_shared<Param>());
+  }
+  return res;
+}
+
+std::vector<std::shared_ptr<Constant>> create_constants(int n_constants) {
+  std::vector<std::shared_ptr<Constant>> res;
+  for (int i = 0; i < n_constants; ++i) {
+    res.push_back(std::make_shared<Constant>());
+  }
+  return res;
+}
+
+std::shared_ptr<Node>
+appsi_operator_from_pyomo_expr(py::handle expr, py::handle var_map,
+                               py::handle param_map,
+                               PyomoExprTypes &expr_types) {
+  std::shared_ptr<Node> res;
+  ExprType tmp_type =
+      expr_types.expr_type_map[py::type::of(expr)].cast<ExprType>();
+
+  switch (tmp_type) {
+  case py_float: {
+    res = std::make_shared<Constant>(expr.cast<double>());
+    break;
+  }
+  case var: {
+    res = var_map[expr_types.id(expr)].cast<std::shared_ptr<Node>>();
+    break;
+  }
+  case param: {
+    if (expr.attr("parent_component")().attr("mutable").cast<bool>())
+        res = param_map[expr_types.id(expr)].cast<std::shared_ptr<Node>>();
+    else
+        res = std::make_shared<Constant>(expr.attr("value").cast<double>());
+    break;
+  }
+  case product: {
+    res = std::make_shared<MultiplyOperator>();
+    break;
+  }
+  case sum: {
+    res = std::make_shared<SumOperator>(expr.attr("nargs")().cast<int>());
+    break;
+  }
+  case negation: {
+    res = std::make_shared<NegationOperator>();
+    break;
+  }
+  case external_func: {
+    res = std::make_shared<ExternalOperator>(expr.attr("nargs")().cast<int>());
+    std::shared_ptr<ExternalOperator> oper =
+        std::dynamic_pointer_cast<ExternalOperator>(res);
+    oper->function_name =
+        expr.attr("_fcn").attr("_function").cast<std::string>();
+    break;
+  }
+  case power: {
+    res = std::make_shared<PowerOperator>();
+    break;
+  }
+  case division: {
+    res = std::make_shared<DivideOperator>();
+    break;
+  }
+  case unary_func: {
+    std::string function_name = expr.attr("getname")().cast<std::string>();
+    if (function_name == "exp")
+      res = std::make_shared<ExpOperator>();
+    else if (function_name == "log")
+      res = std::make_shared<LogOperator>();
+    else if (function_name == "log10")
+      res = std::make_shared<Log10Operator>();
+    else if (function_name == "sin")
+      res = std::make_shared<SinOperator>();
+    else if (function_name == "cos")
+      res = std::make_shared<CosOperator>();
+    else if (function_name == "tan")
+      res = std::make_shared<TanOperator>();
+    else if (function_name == "asin")
+      res = std::make_shared<AsinOperator>();
+    else if (function_name == "acos")
+      res = std::make_shared<AcosOperator>();
+    else if (function_name == "atan")
+      res = std::make_shared<AtanOperator>();
+    else if (function_name == "sqrt")
+      res = std::make_shared<SqrtOperator>();
+    else
+      throw py::value_error("Unrecognized expression type: " + function_name);
+    break;
+  }
+  case linear: {
+    res = std::make_shared<LinearOperator>(
+        expr_types.len(expr.attr("linear_vars")).cast<int>());
+    break;
+  }
+  case named_expr: {
+    res = appsi_operator_from_pyomo_expr(expr.attr("expr"), var_map, param_map,
+                                         expr_types);
+    break;
+  }
+  case numeric_constant: {
+    res = std::make_shared<Constant>(expr.attr("value").cast<double>());
+    break;
+  }
+  case pyomo_unit: {
+    res = std::make_shared<Constant>(1.0);
+    break;
+  }
+  case unary_abs: {
+    res = std::make_shared<AbsOperator>();
+    break;
+  }
+  default: {
+    throw py::value_error("Unrecognized expression type: " +
+                          expr_types.builtins.attr("str")(py::type::of(expr))
+                              .cast<std::string>());
+    break;
+  }
+  }
+  return res;
+}
+
+void prep_for_repn_helper(py::handle expr, py::handle named_exprs,
+                          py::handle variables, py::handle fixed_vars,
+                          py::handle external_funcs,
+                          PyomoExprTypes &expr_types) {
+  ExprType tmp_type =
+      expr_types.expr_type_map[py::type::of(expr)].cast<ExprType>();
+
+  switch (tmp_type) {
+  case py_float: {
+    break;
+  }
+  case var: {
+    variables[expr_types.id(expr)] = expr;
+    if (expr.attr("fixed").cast<bool>()) {
+      fixed_vars[expr_types.id(expr)] = expr;
+    }
+    break;
+  }
+  case param: {
+    break;
+  }
+  case product: {
+    py::tuple args = expr.attr("_args_");
+    for (py::handle arg : args) {
+      prep_for_repn_helper(arg, named_exprs, variables, fixed_vars,
+                           external_funcs, expr_types);
+    }
+    break;
+  }
+  case sum: {
+    py::tuple args = expr.attr("args");
+    for (py::handle arg : args) {
+      prep_for_repn_helper(arg, named_exprs, variables, fixed_vars,
+                           external_funcs, expr_types);
+    }
+    break;
+  }
+  case negation: {
+    py::tuple args = expr.attr("_args_");
+    for (py::handle arg : args) {
+      prep_for_repn_helper(arg, named_exprs, variables, fixed_vars,
+                           external_funcs, expr_types);
+    }
+    break;
+  }
+  case external_func: {
+    external_funcs[expr_types.id(expr)] = expr;
+    py::tuple args = expr.attr("args");
+    for (py::handle arg : args) {
+      prep_for_repn_helper(arg, named_exprs, variables, fixed_vars,
+                           external_funcs, expr_types);
+    }
+    break;
+  }
+  case power: {
+    py::tuple args = expr.attr("_args_");
+    for (py::handle arg : args) {
+      prep_for_repn_helper(arg, named_exprs, variables, fixed_vars,
+                           external_funcs, expr_types);
+    }
+    break;
+  }
+  case division: {
+    py::tuple args = expr.attr("_args_");
+    for (py::handle arg : args) {
+      prep_for_repn_helper(arg, named_exprs, variables, fixed_vars,
+                           external_funcs, expr_types);
+    }
+    break;
+  }
+  case unary_func: {
+    py::tuple args = expr.attr("_args_");
+    for (py::handle arg : args) {
+      prep_for_repn_helper(arg, named_exprs, variables, fixed_vars,
+                           external_funcs, expr_types);
+    }
+    break;
+  }
+  case linear: {
+    py::list linear_vars = expr.attr("linear_vars");
+    py::list linear_coefs = expr.attr("linear_coefs");
+    for (py::handle arg : linear_vars) {
+      prep_for_repn_helper(arg, named_exprs, variables, fixed_vars,
+                           external_funcs, expr_types);
+    }
+    for (py::handle arg : linear_coefs) {
+      prep_for_repn_helper(arg, named_exprs, variables, fixed_vars,
+                           external_funcs, expr_types);
+    }
+    prep_for_repn_helper(expr.attr("constant"), named_exprs, variables,
+                         fixed_vars, external_funcs, expr_types);
+    break;
+  }
+  case named_expr: {
+    named_exprs[expr_types.id(expr)] = expr;
+    prep_for_repn_helper(expr.attr("expr"), named_exprs, variables, fixed_vars,
+                         external_funcs, expr_types);
+    break;
+  }
+  case numeric_constant: {
+    break;
+  }
+  case pyomo_unit: {
+    break;
+  }
+  case unary_abs: {
+    py::tuple args = expr.attr("_args_");
+    for (py::handle arg : args) {
+      prep_for_repn_helper(arg, named_exprs, variables, fixed_vars,
+                           external_funcs, expr_types);
+    }
+    break;
+  }
+  default: {
+    if (expr_types.builtins.attr("hasattr")(expr, "is_constant").cast<bool>()) {
+      if (expr.attr("is_constant")().cast<bool>())
+        break;
+    }
+    throw py::value_error("Unrecognized expression type: " +
+                          expr_types.builtins.attr("str")(py::type::of(expr))
+                              .cast<std::string>());
+    break;
+  }
+  }
+}
+
+py::tuple prep_for_repn(py::handle expr, PyomoExprTypes &expr_types) {
+  py::dict named_exprs;
+  py::dict variables;
+  py::dict fixed_vars;
+  py::dict external_funcs;
+
+  prep_for_repn_helper(expr, named_exprs, variables, fixed_vars, external_funcs,
+                       expr_types);
+
+  py::list named_expr_list = named_exprs.attr("values")();
+  py::list variable_list = variables.attr("values")();
+  py::list fixed_var_list = fixed_vars.attr("values")();
+  py::list external_func_list = external_funcs.attr("values")();
+
+  py::tuple res = py::make_tuple(named_expr_list, variable_list, fixed_var_list,
+                                 external_func_list);
+  return res;
+}
+
+int build_expression_tree(py::handle pyomo_expr,
+                          std::shared_ptr<Node> appsi_expr, py::handle var_map,
+                          py::handle param_map, PyomoExprTypes &expr_types) {
+  int num_nodes = 0;
+
+  if (expr_types.expr_type_map[py::type::of(pyomo_expr)].cast<ExprType>() ==
+      named_expr)
+    return build_expression_tree(pyomo_expr.attr("expr"), appsi_expr, var_map,
+                                 param_map, expr_types);
+
+  if (appsi_expr->is_leaf()) {
+    ;
+  } else if (appsi_expr->is_binary_operator()) {
+    num_nodes += 1;
+    std::shared_ptr<BinaryOperator> oper =
+        std::dynamic_pointer_cast<BinaryOperator>(appsi_expr);
+    py::list pyomo_args = pyomo_expr.attr("args");
+    oper->operand1 = appsi_operator_from_pyomo_expr(pyomo_args[0], var_map,
+                                                    param_map, expr_types);
+    oper->operand2 = appsi_operator_from_pyomo_expr(pyomo_args[1], var_map,
+                                                    param_map, expr_types);
+    num_nodes += build_expression_tree(pyomo_args[0], oper->operand1, var_map,
+                                       param_map, expr_types);
+    num_nodes += build_expression_tree(pyomo_args[1], oper->operand2, var_map,
+                                       param_map, expr_types);
+  } else if (appsi_expr->is_unary_operator()) {
+    num_nodes += 1;
+    std::shared_ptr<UnaryOperator> oper =
+        std::dynamic_pointer_cast<UnaryOperator>(appsi_expr);
+    py::list pyomo_args = pyomo_expr.attr("args");
+    oper->operand = appsi_operator_from_pyomo_expr(pyomo_args[0], var_map,
+                                                   param_map, expr_types);
+    num_nodes += build_expression_tree(pyomo_args[0], oper->operand, var_map,
+                                       param_map, expr_types);
+  } else if (appsi_expr->is_sum_operator()) {
+    num_nodes += 1;
+    std::shared_ptr<SumOperator> oper =
+        std::dynamic_pointer_cast<SumOperator>(appsi_expr);
+    py::list pyomo_args = pyomo_expr.attr("args");
+    for (unsigned int arg_ndx = 0; arg_ndx < oper->nargs; ++arg_ndx) {
+      oper->operands[arg_ndx] = appsi_operator_from_pyomo_expr(
+          pyomo_args[arg_ndx], var_map, param_map, expr_types);
+      num_nodes +=
+          build_expression_tree(pyomo_args[arg_ndx], oper->operands[arg_ndx],
+                                var_map, param_map, expr_types);
+    }
+  } else if (appsi_expr->is_linear_operator()) {
+    num_nodes += 1;
+    std::shared_ptr<LinearOperator> oper =
+        std::dynamic_pointer_cast<LinearOperator>(appsi_expr);
+    oper->constant = appsi_expr_from_pyomo_expr(pyomo_expr.attr("constant"),
+                                                var_map, param_map, expr_types);
+    py::list pyomo_vars = pyomo_expr.attr("linear_vars");
+    py::list pyomo_coefs = pyomo_expr.attr("linear_coefs");
+    for (unsigned int arg_ndx = 0; arg_ndx < oper->nterms; ++arg_ndx) {
+      oper->variables[arg_ndx] = var_map[expr_types.id(pyomo_vars[arg_ndx])]
+                                     .cast<std::shared_ptr<Var>>();
+      oper->coefficients[arg_ndx] = appsi_expr_from_pyomo_expr(
+          pyomo_coefs[arg_ndx], var_map, param_map, expr_types);
+    }
+  } else if (appsi_expr->is_external_operator()) {
+    num_nodes += 1;
+    std::shared_ptr<ExternalOperator> oper =
+        std::dynamic_pointer_cast<ExternalOperator>(appsi_expr);
+    py::list pyomo_args = pyomo_expr.attr("args");
+    for (unsigned int arg_ndx = 0; arg_ndx < oper->nargs; ++arg_ndx) {
+      oper->operands[arg_ndx] = appsi_operator_from_pyomo_expr(
+          pyomo_args[arg_ndx], var_map, param_map, expr_types);
+      num_nodes +=
+          build_expression_tree(pyomo_args[arg_ndx], oper->operands[arg_ndx],
+                                var_map, param_map, expr_types);
+    }
+  } else {
+    throw py::value_error(
+        "Unrecognized expression type: " +
+        expr_types.builtins.attr("str")(py::type::of(pyomo_expr))
+            .cast<std::string>());
+  }
+  return num_nodes;
+}
+
+std::shared_ptr<ExpressionBase>
+appsi_expr_from_pyomo_expr(py::handle expr, py::handle var_map,
+                           py::handle param_map, PyomoExprTypes &expr_types) {
+  std::shared_ptr<Node> node =
+      appsi_operator_from_pyomo_expr(expr, var_map, param_map, expr_types);
+  int num_nodes =
+      build_expression_tree(expr, node, var_map, param_map, expr_types);
+  if (num_nodes == 0) {
+    return std::dynamic_pointer_cast<ExpressionBase>(node);
+  } else {
+    std::shared_ptr<Expression> res = std::make_shared<Expression>(num_nodes);
+    node->fill_expression(res->operators, num_nodes);
+    return res;
+  }
+}
+
+std::vector<std::shared_ptr<ExpressionBase>>
+appsi_exprs_from_pyomo_exprs(py::list expr_list, py::dict var_map,
+                             py::dict param_map) {
+  PyomoExprTypes expr_types = PyomoExprTypes();
+  int num_exprs = expr_types.builtins.attr("len")(expr_list).cast<int>();
+  std::vector<std::shared_ptr<ExpressionBase>> res(num_exprs);
+
+  int ndx = 0;
+  for (py::handle expr : expr_list) {
+    res[ndx] = appsi_expr_from_pyomo_expr(expr, var_map, param_map, expr_types);
+    ndx += 1;
+  }
+  return res;
+}
+
+void process_pyomo_vars(PyomoExprTypes &expr_types, py::list pyomo_vars,
+                        py::dict var_map, py::dict param_map,
+                        py::dict var_attrs, py::dict rev_var_map,
+                        py::bool_ _set_name, py::handle symbol_map,
+                        py::handle labeler, py::bool_ _update) {
+  py::tuple v_attrs;
+  std::shared_ptr<Var> cv;
+  py::handle v_lb;
+  py::handle v_ub;
+  py::handle v_val;
+  py::tuple domain_interval;
+  py::handle interval_lb;
+  py::handle interval_ub;
+  py::handle interval_step;
+  bool v_fixed;
+  bool set_name = _set_name.cast<bool>();
+  bool update = _update.cast<bool>();
+  double domain_step;
+
+  for (py::handle v : pyomo_vars) {
+    v_attrs = var_attrs[expr_types.id(v)];
+    v_lb = v_attrs[1];
+    v_ub = v_attrs[2];
+    v_fixed = v_attrs[3].cast<bool>();
+    domain_interval = v_attrs[4];
+    v_val = v_attrs[5];
+
+    interval_lb = domain_interval[0];
+    interval_ub = domain_interval[1];
+    interval_step = domain_interval[2];
+    domain_step = interval_step.cast<double>();
+
+    if (update) {
+      cv = var_map[expr_types.id(v)].cast<std::shared_ptr<Var>>();
+    } else {
+      cv = std::make_shared<Var>();
+    }
+
+    if (!(v_lb.is(py::none()))) {
+      cv->lb = appsi_expr_from_pyomo_expr(v_lb, var_map, param_map, expr_types);
+    } else {
+      cv->lb = std::make_shared<Constant>(-inf);
+    }
+    if (!(v_ub.is(py::none()))) {
+      cv->ub = appsi_expr_from_pyomo_expr(v_ub, var_map, param_map, expr_types);
+    } else {
+      cv->ub = std::make_shared<Constant>(inf);
+    }
+
+    if (!(v_val.is(py::none()))) {
+      cv->value = v_val.cast<double>();
+    }
+
+    if (v_fixed) {
+      cv->fixed = true;
+    } else {
+      cv->fixed = false;
+    }
+
+    if (set_name && !update) {
+      cv->name = symbol_map.attr("getSymbol")(v, labeler).cast<std::string>();
+    }
+
+    if (interval_lb.is(py::none()))
+      cv->domain_lb = -inf;
+    else
+      cv->domain_lb = interval_lb.cast<double>();
+    if (interval_ub.is(py::none()))
+      cv->domain_ub = inf;
+    else
+      cv->domain_ub = interval_ub.cast<double>();
+    if (domain_step == 0)
+      cv->domain = continuous;
+    else if (domain_step == 1) {
+      if ((cv->domain_lb == 0) && (cv->domain_ub == 1))
+        cv->domain = binary;
+      else
+        cv->domain = integers;
+    } else
+      throw py::value_error("Unrecognized domain step");
+
+    if (!update) {
+      var_map[expr_types.id(v)] = py::cast(cv);
+      rev_var_map[py::cast(cv)] = v;
+    }
+  }
+}
diff --git a/pyomo/contrib/appsi/cmodel/src/expression.hpp b/pyomo/contrib/appsi/cmodel/src/expression.hpp
index 9a991102a90..e91ca0af3b3 100644
--- a/pyomo/contrib/appsi/cmodel/src/expression.hpp
+++ b/pyomo/contrib/appsi/cmodel/src/expression.hpp
@@ -1,788 +1,800 @@
-#ifndef EXPRESSION_HEADER
-#define EXPRESSION_HEADER
-
-#include "interval.hpp"
-#include <mutex>
-
-class Node;
-class ExpressionBase;
-class Leaf;
-class Var;
-class Constant;
-class Param;
-class Expression;
-class Operator;
-class BinaryOperator;
-class UnaryOperator;
-class LinearOperator;
-class SumOperator;
-class MultiplyOperator;
-class DivideOperator;
-class PowerOperator;
-class NegationOperator;
-class ExpOperator;
-class LogOperator;
-class AbsOperator;
-class ExternalOperator;
-class PyomoExprTypes;
-
-extern double inf;
-
-class Node : public std::enable_shared_from_this<Node> {
-public:
-  Node() = default;
-  virtual ~Node() = default;
-  virtual bool is_variable_type() { return false; }
-  virtual bool is_param_type() { return false; }
-  virtual bool is_expression_type() { return false; }
-  virtual bool is_operator_type() { return false; }
-  virtual bool is_constant_type() { return false; }
-  virtual bool is_leaf() { return false; }
-  virtual bool is_binary_operator() { return false; }
-  virtual bool is_unary_operator() { return false; }
-  virtual bool is_linear_operator() { return false; }
-  virtual bool is_sum_operator() { return false; }
-  virtual bool is_multiply_operator() { return false; }
-  virtual bool is_divide_operator() { return false; }
-  virtual bool is_power_operator() { return false; }
-  virtual bool is_negation_operator() { return false; }
-  virtual bool is_exp_operator() { return false; }
-  virtual bool is_log_operator() { return false; }
-  virtual bool is_abs_operator() { return false; }
-  virtual bool is_sqrt_operator() { return false; }
-  virtual bool is_external_operator() { return false; }
-  virtual double get_value_from_array(double *) = 0;
-  virtual int get_degree_from_array(int *) = 0;
-  virtual std::string get_string_from_array(std::string *) = 0;
-  virtual void fill_prefix_notation_stack(
-      std::shared_ptr<std::vector<std::shared_ptr<Node>>> stack) = 0;
-  virtual void write_nl_string(std::ofstream &) = 0;
-  virtual void fill_expression(std::shared_ptr<Operator> *oper_array,
-                               int &oper_ndx) = 0;
-  virtual double get_lb_from_array(double *lbs) = 0;
-  virtual double get_ub_from_array(double *ubs) = 0;
-  virtual void
-  set_bounds_in_array(double new_lb, double new_ub, double *lbs, double *ubs,
-                      double feasibility_tol, double integer_tol,
-                      double improvement_tol,
-                      std::set<std::shared_ptr<Var>> &improved_vars) = 0;
-};
-
-class ExpressionBase : public Node {
-public:
-  ExpressionBase() = default;
-  virtual double evaluate() = 0;
-  virtual std::string __str__() = 0;
-  virtual std::shared_ptr<std::vector<std::shared_ptr<Var>>>
-  identify_variables() = 0;
-  virtual std::shared_ptr<std::vector<std::shared_ptr<ExternalOperator>>>
-  identify_external_operators() = 0;
-  virtual std::shared_ptr<std::vector<std::shared_ptr<Node>>>
-  get_prefix_notation() = 0;
-  std::shared_ptr<ExpressionBase> shared_from_this() {
-    return std::static_pointer_cast<ExpressionBase>(Node::shared_from_this());
-  }
-  void fill_prefix_notation_stack(
-      std::shared_ptr<std::vector<std::shared_ptr<Node>>> stack) override {
-    ;
-  }
-};
-
-class Leaf : public ExpressionBase {
-public:
-  Leaf() = default;
-  Leaf(double value) : value(value) {}
-  virtual ~Leaf() = default;
-  double value = 0.0;
-  bool is_leaf() override;
-  double evaluate() override;
-  double get_value_from_array(double *) override;
-  std::string get_string_from_array(std::string *) override;
-  std::shared_ptr<std::vector<std::shared_ptr<Node>>>
-  get_prefix_notation() override;
-  void fill_expression(std::shared_ptr<Operator> *oper_array,
-                       int &oper_ndx) override;
-  double get_lb_from_array(double *lbs) override;
-  double get_ub_from_array(double *ubs) override;
-  void
-  set_bounds_in_array(double new_lb, double new_ub, double *lbs, double *ubs,
-                      double feasibility_tol, double integer_tol,
-                      double improvement_tol,
-                      std::set<std::shared_ptr<Var>> &improved_vars) override;
-};
-
-class Constant : public Leaf {
-public:
-  Constant() = default;
-  Constant(double value) : Leaf(value) {}
-  bool is_constant_type() override;
-  std::string __str__() override;
-  int get_degree_from_array(int *) override;
-  std::shared_ptr<std::vector<std::shared_ptr<Var>>>
-  identify_variables() override;
-  std::shared_ptr<std::vector<std::shared_ptr<ExternalOperator>>>
-  identify_external_operators() override;
-  void write_nl_string(std::ofstream &) override;
-};
-
-enum Domain { continuous, binary, integers };
-
-class Var : public Leaf {
-public:
-  Var() = default;
-  Var(double val) : Leaf(val) {}
-  Var(std::string _name) : name(_name) {}
-  Var(std::string _name, double val) : Leaf(val), name(_name) {}
-  std::string name = "v";
-  std::string __str__() override;
-  std::shared_ptr<ExpressionBase> lb;
-  std::shared_ptr<ExpressionBase> ub;
-  int index = -1;
-  bool fixed = false;
-  double domain_lb = -inf;
-  double domain_ub = inf;
-  Domain domain = continuous;
-  bool is_variable_type() override;
-  int get_degree_from_array(int *) override;
-  std::shared_ptr<std::vector<std::shared_ptr<Var>>>
-  identify_variables() override;
-  std::shared_ptr<std::vector<std::shared_ptr<ExternalOperator>>>
-  identify_external_operators() override;
-  void write_nl_string(std::ofstream &) override;
-  std::shared_ptr<Var> shared_from_this() {
-    return std::static_pointer_cast<Var>(Node::shared_from_this());
-  }
-  double get_lb();
-  double get_ub();
-  Domain get_domain();
-  double get_lb_from_array(double *lbs) override;
-  double get_ub_from_array(double *ubs) override;
-  void
-  set_bounds_in_array(double new_lb, double new_ub, double *lbs, double *ubs,
-                      double feasibility_tol, double integer_tol,
-                      double improvement_tol,
-                      std::set<std::shared_ptr<Var>> &improved_vars) override;
-};
-
-class Param : public Leaf {
-public:
-  Param() = default;
-  Param(double val) : Leaf(val) {}
-  Param(std::string _name) : name(_name) {}
-  Param(std::string _name, double val) : Leaf(val), name(_name) {}
-  std::string name = "p";
-  std::string __str__() override;
-  bool is_param_type() override;
-  int get_degree_from_array(int *) override;
-  std::shared_ptr<std::vector<std::shared_ptr<Var>>>
-  identify_variables() override;
-  std::shared_ptr<std::vector<std::shared_ptr<ExternalOperator>>>
-  identify_external_operators() override;
-  void write_nl_string(std::ofstream &) override;
-};
-
-class Expression : public ExpressionBase {
-public:
-  Expression(int _n_operators) : ExpressionBase() {
-    operators = new std::shared_ptr<Operator>[_n_operators];
-    n_operators = _n_operators;
-  }
-  ~Expression() { delete[] operators; }
-  std::string __str__() override;
-  bool is_expression_type() override;
-  double evaluate() override;
-  double get_value_from_array(double *) override;
-  int get_degree_from_array(int *) override;
-  std::shared_ptr<std::vector<std::shared_ptr<Var>>>
-  identify_variables() override;
-  std::shared_ptr<std::vector<std::shared_ptr<ExternalOperator>>>
-  identify_external_operators() override;
-  std::string get_string_from_array(std::string *) override;
-  std::shared_ptr<std::vector<std::shared_ptr<Node>>>
-  get_prefix_notation() override;
-  void write_nl_string(std::ofstream &) override;
-  std::vector<std::shared_ptr<Operator>> get_operators();
-  std::shared_ptr<Operator> *operators;
-  unsigned int n_operators;
-  void fill_expression(std::shared_ptr<Operator> *oper_array,
-                       int &oper_ndx) override;
-  void propagate_bounds_forward(double *lbs, double *ubs,
-                                double feasibility_tol, double integer_tol);
-  void propagate_bounds_backward(double *lbs, double *ubs,
-                                 double feasibility_tol, double integer_tol,
-                                 double improvement_tol,
-                                 std::set<std::shared_ptr<Var>> &improved_vars);
-  double get_lb_from_array(double *lbs) override;
-  double get_ub_from_array(double *ubs) override;
-  void
-  set_bounds_in_array(double new_lb, double new_ub, double *lbs, double *ubs,
-                      double feasibility_tol, double integer_tol,
-                      double improvement_tol,
-                      std::set<std::shared_ptr<Var>> &improved_vars) override;
-};
-
-class Operator : public Node {
-public:
-  Operator() = default;
-  int index = 0;
-  virtual void evaluate(double *values) = 0;
-  virtual void propagate_degree_forward(int *degrees, double *values) = 0;
-  virtual void
-  identify_variables(std::set<std::shared_ptr<Node>> &,
-                     std::shared_ptr<std::vector<std::shared_ptr<Var>>>) = 0;
-  std::shared_ptr<Operator> shared_from_this() {
-    return std::static_pointer_cast<Operator>(Node::shared_from_this());
-  }
-  bool is_operator_type() override;
-  double get_value_from_array(double *) override;
-  int get_degree_from_array(int *) override;
-  std::string get_string_from_array(std::string *) override;
-  virtual void print(std::string *) = 0;
-  virtual std::string name() = 0;
-  virtual void propagate_bounds_forward(double *lbs, double *ubs,
-                                        double feasibility_tol,
-                                        double integer_tol);
-  virtual void
-  propagate_bounds_backward(double *lbs, double *ubs, double feasibility_tol,
-                            double integer_tol, double improvement_tol,
-                            std::set<std::shared_ptr<Var>> &improved_vars);
-  double get_lb_from_array(double *lbs) override;
-  double get_ub_from_array(double *ubs) override;
-  void
-  set_bounds_in_array(double new_lb, double new_ub, double *lbs, double *ubs,
-                      double feasibility_tol, double integer_tol,
-                      double improvement_tol,
-                      std::set<std::shared_ptr<Var>> &improved_vars) override;
-};
-
-class BinaryOperator : public Operator {
-public:
-  BinaryOperator() = default;
-  virtual ~BinaryOperator() = default;
-  void identify_variables(
-      std::set<std::shared_ptr<Node>> &,
-      std::shared_ptr<std::vector<std::shared_ptr<Var>>>) override;
-  std::shared_ptr<Node> operand1;
-  std::shared_ptr<Node> operand2;
-  void fill_prefix_notation_stack(
-      std::shared_ptr<std::vector<std::shared_ptr<Node>>> stack) override;
-  bool is_binary_operator() override;
-  void fill_expression(std::shared_ptr<Operator> *oper_array,
-                       int &oper_ndx) override;
-};
-
-class UnaryOperator : public Operator {
-public:
-  UnaryOperator() = default;
-  virtual ~UnaryOperator() = default;
-  void identify_variables(
-      std::set<std::shared_ptr<Node>> &,
-      std::shared_ptr<std::vector<std::shared_ptr<Var>>>) override;
-  std::shared_ptr<Node> operand;
-  void fill_prefix_notation_stack(
-      std::shared_ptr<std::vector<std::shared_ptr<Node>>> stack) override;
-  bool is_unary_operator() override;
-  void propagate_degree_forward(int *degrees, double *values) override;
-  void fill_expression(std::shared_ptr<Operator> *oper_array,
-                       int &oper_ndx) override;
-};
-
-class LinearOperator : public Operator {
-public:
-  LinearOperator(int _nterms) {
-    variables = new std::shared_ptr<Var>[_nterms];
-    coefficients = new std::shared_ptr<ExpressionBase>[_nterms];
-    nterms = _nterms;
-  }
-  ~LinearOperator() {
-    delete[] variables;
-    delete[] coefficients;
-  }
-  void identify_variables(
-      std::set<std::shared_ptr<Node>> &,
-      std::shared_ptr<std::vector<std::shared_ptr<Var>>>) override;
-  std::shared_ptr<Var> *variables;
-  std::shared_ptr<ExpressionBase> *coefficients;
-  std::shared_ptr<ExpressionBase> constant = std::make_shared<Constant>(0);
-  void evaluate(double *values) override;
-  void propagate_degree_forward(int *degrees, double *values) override;
-  void print(std::string *) override;
-  std::string name() override { return "LinearOperator"; };
-  void write_nl_string(std::ofstream &) override;
-  void fill_prefix_notation_stack(
-      std::shared_ptr<std::vector<std::shared_ptr<Node>>> stack) override;
-  bool is_linear_operator() override;
-  unsigned int nterms;
-  void fill_expression(std::shared_ptr<Operator> *oper_array,
-                       int &oper_ndx) override;
-  void propagate_bounds_forward(double *lbs, double *ubs,
-                                double feasibility_tol,
-                                double integer_tol) override;
-  void propagate_bounds_backward(
-      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-      double improvement_tol,
-      std::set<std::shared_ptr<Var>> &improved_vars) override;
-};
-
-class SumOperator : public Operator {
-public:
-  SumOperator(int _nargs) {
-    operands = new std::shared_ptr<Node>[_nargs];
-    nargs = _nargs;
-  }
-  ~SumOperator() { delete[] operands; }
-  void identify_variables(
-      std::set<std::shared_ptr<Node>> &,
-      std::shared_ptr<std::vector<std::shared_ptr<Var>>>) override;
-  void evaluate(double *values) override;
-  void propagate_degree_forward(int *degrees, double *values) override;
-  void print(std::string *) override;
-  std::string name() override { return "SumOperator"; };
-  void write_nl_string(std::ofstream &) override;
-  void fill_prefix_notation_stack(
-      std::shared_ptr<std::vector<std::shared_ptr<Node>>> stack) override;
-  bool is_sum_operator() override;
-  std::shared_ptr<Node> *operands;
-  unsigned int nargs;
-  void fill_expression(std::shared_ptr<Operator> *oper_array,
-                       int &oper_ndx) override;
-  void propagate_bounds_forward(double *lbs, double *ubs,
-                                double feasibility_tol,
-                                double integer_tol) override;
-  void propagate_bounds_backward(
-      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-      double improvement_tol,
-      std::set<std::shared_ptr<Var>> &improved_vars) override;
-};
-
-class MultiplyOperator : public BinaryOperator {
-public:
-  MultiplyOperator() = default;
-  void evaluate(double *values) override;
-  void propagate_degree_forward(int *degrees, double *values) override;
-  void print(std::string *) override;
-  std::string name() override { return "MultiplyOperator"; };
-  void write_nl_string(std::ofstream &) override;
-  bool is_multiply_operator() override;
-  void propagate_bounds_forward(double *lbs, double *ubs,
-                                double feasibility_tol,
-                                double integer_tol) override;
-  void propagate_bounds_backward(
-      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-      double improvement_tol,
-      std::set<std::shared_ptr<Var>> &improved_vars) override;
-};
-
-class ExternalOperator : public Operator {
-public:
-  ExternalOperator(int _nargs) {
-    operands = new std::shared_ptr<Node>[_nargs];
-    nargs = _nargs;
-  }
-  ~ExternalOperator() { delete[] operands; }
-  void evaluate(double *values) override;
-  void propagate_degree_forward(int *degrees, double *values) override;
-  void print(std::string *) override;
-  std::string name() override { return "ExternalOperator"; };
-  void write_nl_string(std::ofstream &) override;
-  void fill_prefix_notation_stack(
-      std::shared_ptr<std::vector<std::shared_ptr<Node>>> stack) override;
-  void identify_variables(
-      std::set<std::shared_ptr<Node>> &,
-      std::shared_ptr<std::vector<std::shared_ptr<Var>>>) override;
-  bool is_external_operator() override;
-  std::string function_name;
-  int external_function_index = -1;
-  std::shared_ptr<Node> *operands;
-  unsigned int nargs;
-  void fill_expression(std::shared_ptr<Operator> *oper_array,
-                       int &oper_ndx) override;
-};
-
-class DivideOperator : public BinaryOperator {
-public:
-  DivideOperator() = default;
-  void evaluate(double *values) override;
-  void propagate_degree_forward(int *degrees, double *values) override;
-  void print(std::string *) override;
-  std::string name() override { return "DivideOperator"; };
-  void write_nl_string(std::ofstream &) override;
-  bool is_divide_operator() override;
-  void propagate_bounds_forward(double *lbs, double *ubs,
-                                double feasibility_tol,
-                                double integer_tol) override;
-  void propagate_bounds_backward(
-      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-      double improvement_tol,
-      std::set<std::shared_ptr<Var>> &improved_vars) override;
-};
-
-class PowerOperator : public BinaryOperator {
-public:
-  PowerOperator() = default;
-  void evaluate(double *values) override;
-  void propagate_degree_forward(int *degrees, double *values) override;
-  void print(std::string *) override;
-  std::string name() override { return "PowerOperator"; };
-  void write_nl_string(std::ofstream &) override;
-  bool is_power_operator() override;
-  void propagate_bounds_forward(double *lbs, double *ubs,
-                                double feasibility_tol,
-                                double integer_tol) override;
-  void propagate_bounds_backward(
-      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-      double improvement_tol,
-      std::set<std::shared_ptr<Var>> &improved_vars) override;
-};
-
-class NegationOperator : public UnaryOperator {
-public:
-  NegationOperator() = default;
-  void evaluate(double *values) override;
-  void propagate_degree_forward(int *degrees, double *values) override;
-  void print(std::string *) override;
-  std::string name() override { return "NegationOperator"; };
-  void write_nl_string(std::ofstream &) override;
-  bool is_negation_operator() override;
-  void propagate_bounds_forward(double *lbs, double *ubs,
-                                double feasibility_tol,
-                                double integer_tol) override;
-  void propagate_bounds_backward(
-      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-      double improvement_tol,
-      std::set<std::shared_ptr<Var>> &improved_vars) override;
-};
-
-class ExpOperator : public UnaryOperator {
-public:
-  ExpOperator() = default;
-  void evaluate(double *values) override;
-  void print(std::string *) override;
-  std::string name() override { return "ExpOperator"; };
-  void write_nl_string(std::ofstream &) override;
-  bool is_exp_operator() override;
-  void propagate_bounds_forward(double *lbs, double *ubs,
-                                double feasibility_tol,
-                                double integer_tol) override;
-  void propagate_bounds_backward(
-      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-      double improvement_tol,
-      std::set<std::shared_ptr<Var>> &improved_vars) override;
-};
-
-class LogOperator : public UnaryOperator {
-public:
-  LogOperator() = default;
-  void evaluate(double *values) override;
-  void print(std::string *) override;
-  std::string name() override { return "LogOperator"; };
-  void write_nl_string(std::ofstream &) override;
-  bool is_log_operator() override;
-  void propagate_bounds_forward(double *lbs, double *ubs,
-                                double feasibility_tol,
-                                double integer_tol) override;
-  void propagate_bounds_backward(
-      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-      double improvement_tol,
-      std::set<std::shared_ptr<Var>> &improved_vars) override;
-};
-
-class AbsOperator : public UnaryOperator {
-public:
-  AbsOperator() = default;
-  void evaluate(double *values) override;
-  void print(std::string *) override;
-  std::string name() override { return "AbsOperator"; };
-  void write_nl_string(std::ofstream &) override;
-  bool is_abs_operator() override;
-  void propagate_bounds_forward(double *lbs, double *ubs,
-                                double feasibility_tol,
-                                double integer_tol) override;
-  void propagate_bounds_backward(
-      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-      double improvement_tol,
-      std::set<std::shared_ptr<Var>> &improved_vars) override;
-};
-
-class SqrtOperator : public UnaryOperator {
-public:
-  SqrtOperator() = default;
-  void evaluate(double *values) override;
-  void print(std::string *) override;
-  std::string name() override { return "SqrtOperator"; };
-  void write_nl_string(std::ofstream &) override;
-  bool is_sqrt_operator() override;
-  void propagate_bounds_forward(double *lbs, double *ubs,
-                                double feasibility_tol,
-                                double integer_tol) override;
-  void propagate_bounds_backward(
-      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-      double improvement_tol,
-      std::set<std::shared_ptr<Var>> &improved_vars) override;
-};
-
-class Log10Operator : public UnaryOperator {
-public:
-  Log10Operator() = default;
-  void evaluate(double *values) override;
-  void print(std::string *) override;
-  std::string name() override { return "Log10Operator"; };
-  void write_nl_string(std::ofstream &) override;
-  void propagate_bounds_forward(double *lbs, double *ubs,
-                                double feasibility_tol,
-                                double integer_tol) override;
-  void propagate_bounds_backward(
-      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-      double improvement_tol,
-      std::set<std::shared_ptr<Var>> &improved_vars) override;
-};
-
-class SinOperator : public UnaryOperator {
-public:
-  SinOperator() = default;
-  void evaluate(double *values) override;
-  void print(std::string *) override;
-  std::string name() override { return "SinOperator"; };
-  void write_nl_string(std::ofstream &) override;
-  void propagate_bounds_forward(double *lbs, double *ubs,
-                                double feasibility_tol,
-                                double integer_tol) override;
-  void propagate_bounds_backward(
-      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-      double improvement_tol,
-      std::set<std::shared_ptr<Var>> &improved_vars) override;
-};
-
-class CosOperator : public UnaryOperator {
-public:
-  CosOperator() = default;
-  void evaluate(double *values) override;
-  void print(std::string *) override;
-  std::string name() override { return "CosOperator"; };
-  void write_nl_string(std::ofstream &) override;
-  void propagate_bounds_forward(double *lbs, double *ubs,
-                                double feasibility_tol,
-                                double integer_tol) override;
-  void propagate_bounds_backward(
-      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-      double improvement_tol,
-      std::set<std::shared_ptr<Var>> &improved_vars) override;
-};
-
-class TanOperator : public UnaryOperator {
-public:
-  TanOperator() = default;
-  void evaluate(double *values) override;
-  void print(std::string *) override;
-  std::string name() override { return "TanOperator"; };
-  void write_nl_string(std::ofstream &) override;
-  void propagate_bounds_forward(double *lbs, double *ubs,
-                                double feasibility_tol,
-                                double integer_tol) override;
-  void propagate_bounds_backward(
-      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-      double improvement_tol,
-      std::set<std::shared_ptr<Var>> &improved_vars) override;
-};
-
-class AsinOperator : public UnaryOperator {
-public:
-  AsinOperator() = default;
-  void evaluate(double *values) override;
-  void print(std::string *) override;
-  std::string name() override { return "AsinOperator"; };
-  void write_nl_string(std::ofstream &) override;
-  void propagate_bounds_forward(double *lbs, double *ubs,
-                                double feasibility_tol,
-                                double integer_tol) override;
-  void propagate_bounds_backward(
-      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-      double improvement_tol,
-      std::set<std::shared_ptr<Var>> &improved_vars) override;
-};
-
-class AcosOperator : public UnaryOperator {
-public:
-  AcosOperator() = default;
-  void evaluate(double *values) override;
-  void print(std::string *) override;
-  std::string name() override { return "AcosOperator"; };
-  void write_nl_string(std::ofstream &) override;
-  void propagate_bounds_forward(double *lbs, double *ubs,
-                                double feasibility_tol,
-                                double integer_tol) override;
-  void propagate_bounds_backward(
-      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-      double improvement_tol,
-      std::set<std::shared_ptr<Var>> &improved_vars) override;
-};
-
-class AtanOperator : public UnaryOperator {
-public:
-  AtanOperator() = default;
-  void evaluate(double *values) override;
-  void print(std::string *) override;
-  std::string name() override { return "AtanOperator"; };
-  void write_nl_string(std::ofstream &) override;
-  void propagate_bounds_forward(double *lbs, double *ubs,
-                                double feasibility_tol,
-                                double integer_tol) override;
-  void propagate_bounds_backward(
-      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
-      double improvement_tol,
-      std::set<std::shared_ptr<Var>> &improved_vars) override;
-};
-
-enum ExprType {
-  py_float = 0,
-  var = 1,
-  param = 2,
-  product = 3,
-  sum = 4,
-  negation = 5,
-  external_func = 6,
-  power = 7,
-  division = 8,
-  unary_func = 9,
-  linear = 10,
-  named_expr = 11,
-  numeric_constant = 12,
-  pyomo_unit = 13,
-  unary_abs = 14
-};
-
-class PyomoExprTypes {
-public:
-  PyomoExprTypes() {
-    expr_type_map[int_] = py_float;
-    expr_type_map[float_] = py_float;
-    expr_type_map[np_int16] = py_float;
-    expr_type_map[np_int32] = py_float;
-    expr_type_map[np_int64] = py_float;
-    expr_type_map[np_longlong] = py_float;
-    expr_type_map[np_uint16] = py_float;
-    expr_type_map[np_uint32] = py_float;
-    expr_type_map[np_uint64] = py_float;
-    expr_type_map[np_ulonglong] = py_float;
-    expr_type_map[np_float16] = py_float;
-    expr_type_map[np_float32] = py_float;
-    expr_type_map[np_float64] = py_float;
-    expr_type_map[ScalarVar] = var;
-    expr_type_map[_GeneralVarData] = var;
-    expr_type_map[AutoLinkedBinaryVar] = var;
-    expr_type_map[ScalarParam] = param;
-    expr_type_map[_ParamData] = param;
-    expr_type_map[MonomialTermExpression] = product;
-    expr_type_map[ProductExpression] = product;
-    expr_type_map[NPV_ProductExpression] = product;
-    expr_type_map[SumExpression] = sum;
-    expr_type_map[NPV_SumExpression] = sum;
-    expr_type_map[NegationExpression] = negation;
-    expr_type_map[NPV_NegationExpression] = negation;
-    expr_type_map[ExternalFunctionExpression] = external_func;
-    expr_type_map[NPV_ExternalFunctionExpression] = external_func;
-    expr_type_map[PowExpression] = power;
-    expr_type_map[NPV_PowExpression] = power;
-    expr_type_map[DivisionExpression] = division;
-    expr_type_map[NPV_DivisionExpression] = division;
-    expr_type_map[UnaryFunctionExpression] = unary_func;
-    expr_type_map[NPV_UnaryFunctionExpression] = unary_func;
-    expr_type_map[LinearExpression] = linear;
-    expr_type_map[_GeneralExpressionData] = named_expr;
-    expr_type_map[ScalarExpression] = named_expr;
-    expr_type_map[Integral] = named_expr;
-    expr_type_map[ScalarIntegral] = named_expr;
-    expr_type_map[NumericConstant] = numeric_constant;
-    expr_type_map[_PyomoUnit] = pyomo_unit;
-    expr_type_map[AbsExpression] = unary_abs;
-    expr_type_map[NPV_AbsExpression] = unary_abs;
-  }
-  ~PyomoExprTypes() = default;
-  py::int_ ione = 1;
-  py::float_ fone = 1.0;
-  py::type int_ = py::type::of(ione);
-  py::type float_ = py::type::of(fone);
-  py::object np = py::module_::import("numpy");
-  py::type np_int16 = np.attr("int16");
-  py::type np_int32 = np.attr("int32");
-  py::type np_int64 = np.attr("int64");
-  py::type np_longlong = np.attr("longlong");
-  py::type np_uint16 = np.attr("uint16");
-  py::type np_uint32 = np.attr("uint32");
-  py::type np_uint64 = np.attr("uint64");
-  py::type np_ulonglong = np.attr("ulonglong");
-  py::type np_float16 = np.attr("float16");
-  py::type np_float32 = np.attr("float32");
-  py::type np_float64 = np.attr("float64");
-  py::object ScalarParam =
-      py::module_::import("pyomo.core.base.param").attr("ScalarParam");
-  py::object _ParamData =
-      py::module_::import("pyomo.core.base.param").attr("_ParamData");
-  py::object ScalarVar =
-      py::module_::import("pyomo.core.base.var").attr("ScalarVar");
-  py::object _GeneralVarData =
-      py::module_::import("pyomo.core.base.var").attr("_GeneralVarData");
-  py::object AutoLinkedBinaryVar =
-      py::module_::import("pyomo.gdp.disjunct").attr("AutoLinkedBinaryVar");
-  py::object numeric_expr = py::module_::import("pyomo.core.expr.numeric_expr");
-  py::object NegationExpression = numeric_expr.attr("NegationExpression");
-  py::object NPV_NegationExpression =
-      numeric_expr.attr("NPV_NegationExpression");
-  py::object ExternalFunctionExpression =
-      numeric_expr.attr("ExternalFunctionExpression");
-  py::object NPV_ExternalFunctionExpression =
-      numeric_expr.attr("NPV_ExternalFunctionExpression");
-  py::object PowExpression = numeric_expr.attr("PowExpression");
-  py::object NPV_PowExpression = numeric_expr.attr("NPV_PowExpression");
-  py::object ProductExpression = numeric_expr.attr("ProductExpression");
-  py::object NPV_ProductExpression = numeric_expr.attr("NPV_ProductExpression");
-  py::object MonomialTermExpression =
-      numeric_expr.attr("MonomialTermExpression");
-  py::object DivisionExpression = numeric_expr.attr("DivisionExpression");
-  py::object NPV_DivisionExpression =
-      numeric_expr.attr("NPV_DivisionExpression");
-  py::object SumExpression = numeric_expr.attr("SumExpression");
-  py::object NPV_SumExpression = numeric_expr.attr("NPV_SumExpression");
-  py::object UnaryFunctionExpression =
-      numeric_expr.attr("UnaryFunctionExpression");
-  py::object AbsExpression = numeric_expr.attr("AbsExpression");
-  py::object NPV_AbsExpression = numeric_expr.attr("NPV_AbsExpression");
-  py::object NPV_UnaryFunctionExpression =
-      numeric_expr.attr("NPV_UnaryFunctionExpression");
-  py::object LinearExpression = numeric_expr.attr("LinearExpression");
-  py::object NumericConstant =
-      py::module_::import("pyomo.core.expr.numvalue").attr("NumericConstant");
-  py::object expr_module = py::module_::import("pyomo.core.base.expression");
-  py::object _GeneralExpressionData =
-      expr_module.attr("_GeneralExpressionData");
-  py::object ScalarExpression = expr_module.attr("ScalarExpression");
-  py::object ScalarIntegral =
-      py::module_::import("pyomo.dae.integral").attr("ScalarIntegral");
-  py::object Integral =
-      py::module_::import("pyomo.dae.integral").attr("Integral");
-  py::object _PyomoUnit =
-      py::module_::import("pyomo.core.base.units_container").attr("_PyomoUnit");
-  py::object builtins = py::module_::import("builtins");
-  py::object id = builtins.attr("id");
-  py::object len = builtins.attr("len");
-  py::dict expr_type_map;
-};
-
-std::vector<std::shared_ptr<Var>> create_vars(int n_vars);
-std::vector<std::shared_ptr<Param>> create_params(int n_params);
-std::vector<std::shared_ptr<Constant>> create_constants(int n_constants);
-std::shared_ptr<ExpressionBase>
-appsi_expr_from_pyomo_expr(py::handle expr, py::handle var_map,
-                           py::handle param_map, PyomoExprTypes &expr_types);
-std::vector<std::shared_ptr<ExpressionBase>>
-appsi_exprs_from_pyomo_exprs(py::list expr_list, py::dict var_map,
-                             py::dict param_map);
-py::tuple prep_for_repn(py::handle expr, PyomoExprTypes &expr_types);
-
-void process_pyomo_vars(PyomoExprTypes &expr_types, py::list pyomo_vars,
-                        py::dict var_map, py::dict param_map,
-                        py::dict var_attrs, py::dict rev_var_map,
-                        py::bool_ _set_name, py::handle symbol_map,
-                        py::handle labeler, py::bool_ _update);
-
-#endif
+/**___________________________________________________________________________
+ *
+ * Pyomo: Python Optimization Modeling Objects
+ * Copyright (c) 2008-2024
+ * National Technology and Engineering Solutions of Sandia, LLC
+ * Under the terms of Contract DE-NA0003525 with National Technology and
+ * Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+ * rights in this software.
+ * This software is distributed under the 3-clause BSD License.
+ * ___________________________________________________________________________
+**/
+
+#ifndef EXPRESSION_HEADER
+#define EXPRESSION_HEADER
+
+#include "interval.hpp"
+#include <mutex>
+
+class Node;
+class ExpressionBase;
+class Leaf;
+class Var;
+class Constant;
+class Param;
+class Expression;
+class Operator;
+class BinaryOperator;
+class UnaryOperator;
+class LinearOperator;
+class SumOperator;
+class MultiplyOperator;
+class DivideOperator;
+class PowerOperator;
+class NegationOperator;
+class ExpOperator;
+class LogOperator;
+class AbsOperator;
+class ExternalOperator;
+class PyomoExprTypes;
+
+extern double inf;
+
+class Node : public std::enable_shared_from_this<Node> {
+public:
+  Node() = default;
+  virtual ~Node() = default;
+  virtual bool is_variable_type() { return false; }
+  virtual bool is_param_type() { return false; }
+  virtual bool is_expression_type() { return false; }
+  virtual bool is_operator_type() { return false; }
+  virtual bool is_constant_type() { return false; }
+  virtual bool is_leaf() { return false; }
+  virtual bool is_binary_operator() { return false; }
+  virtual bool is_unary_operator() { return false; }
+  virtual bool is_linear_operator() { return false; }
+  virtual bool is_sum_operator() { return false; }
+  virtual bool is_multiply_operator() { return false; }
+  virtual bool is_divide_operator() { return false; }
+  virtual bool is_power_operator() { return false; }
+  virtual bool is_negation_operator() { return false; }
+  virtual bool is_exp_operator() { return false; }
+  virtual bool is_log_operator() { return false; }
+  virtual bool is_abs_operator() { return false; }
+  virtual bool is_sqrt_operator() { return false; }
+  virtual bool is_external_operator() { return false; }
+  virtual double get_value_from_array(double *) = 0;
+  virtual int get_degree_from_array(int *) = 0;
+  virtual std::string get_string_from_array(std::string *) = 0;
+  virtual void fill_prefix_notation_stack(
+      std::shared_ptr<std::vector<std::shared_ptr<Node>>> stack) = 0;
+  virtual void write_nl_string(std::ofstream &) = 0;
+  virtual void fill_expression(std::shared_ptr<Operator> *oper_array,
+                               int &oper_ndx) = 0;
+  virtual double get_lb_from_array(double *lbs) = 0;
+  virtual double get_ub_from_array(double *ubs) = 0;
+  virtual void
+  set_bounds_in_array(double new_lb, double new_ub, double *lbs, double *ubs,
+                      double feasibility_tol, double integer_tol,
+                      double improvement_tol,
+                      std::set<std::shared_ptr<Var>> &improved_vars) = 0;
+};
+
+class ExpressionBase : public Node {
+public:
+  ExpressionBase() = default;
+  virtual double evaluate() = 0;
+  virtual std::string __str__() = 0;
+  virtual std::shared_ptr<std::vector<std::shared_ptr<Var>>>
+  identify_variables() = 0;
+  virtual std::shared_ptr<std::vector<std::shared_ptr<ExternalOperator>>>
+  identify_external_operators() = 0;
+  virtual std::shared_ptr<std::vector<std::shared_ptr<Node>>>
+  get_prefix_notation() = 0;
+  std::shared_ptr<ExpressionBase> shared_from_this() {
+    return std::static_pointer_cast<ExpressionBase>(Node::shared_from_this());
+  }
+  void fill_prefix_notation_stack(
+      std::shared_ptr<std::vector<std::shared_ptr<Node>>> stack) override {
+    ;
+  }
+};
+
+class Leaf : public ExpressionBase {
+public:
+  Leaf() = default;
+  Leaf(double value) : value(value) {}
+  virtual ~Leaf() = default;
+  double value = 0.0;
+  bool is_leaf() override;
+  double evaluate() override;
+  double get_value_from_array(double *) override;
+  std::string get_string_from_array(std::string *) override;
+  std::shared_ptr<std::vector<std::shared_ptr<Node>>>
+  get_prefix_notation() override;
+  void fill_expression(std::shared_ptr<Operator> *oper_array,
+                       int &oper_ndx) override;
+  double get_lb_from_array(double *lbs) override;
+  double get_ub_from_array(double *ubs) override;
+  void
+  set_bounds_in_array(double new_lb, double new_ub, double *lbs, double *ubs,
+                      double feasibility_tol, double integer_tol,
+                      double improvement_tol,
+                      std::set<std::shared_ptr<Var>> &improved_vars) override;
+};
+
+class Constant : public Leaf {
+public:
+  Constant() = default;
+  Constant(double value) : Leaf(value) {}
+  bool is_constant_type() override;
+  std::string __str__() override;
+  int get_degree_from_array(int *) override;
+  std::shared_ptr<std::vector<std::shared_ptr<Var>>>
+  identify_variables() override;
+  std::shared_ptr<std::vector<std::shared_ptr<ExternalOperator>>>
+  identify_external_operators() override;
+  void write_nl_string(std::ofstream &) override;
+};
+
+enum Domain { continuous, binary, integers };
+
+class Var : public Leaf {
+public:
+  Var() = default;
+  Var(double val) : Leaf(val) {}
+  Var(std::string _name) : name(_name) {}
+  Var(std::string _name, double val) : Leaf(val), name(_name) {}
+  std::string name = "v";
+  std::string __str__() override;
+  std::shared_ptr<ExpressionBase> lb;
+  std::shared_ptr<ExpressionBase> ub;
+  int index = -1;
+  bool fixed = false;
+  double domain_lb = -inf;
+  double domain_ub = inf;
+  Domain domain = continuous;
+  bool is_variable_type() override;
+  int get_degree_from_array(int *) override;
+  std::shared_ptr<std::vector<std::shared_ptr<Var>>>
+  identify_variables() override;
+  std::shared_ptr<std::vector<std::shared_ptr<ExternalOperator>>>
+  identify_external_operators() override;
+  void write_nl_string(std::ofstream &) override;
+  std::shared_ptr<Var> shared_from_this() {
+    return std::static_pointer_cast<Var>(Node::shared_from_this());
+  }
+  double get_lb();
+  double get_ub();
+  Domain get_domain();
+  double get_lb_from_array(double *lbs) override;
+  double get_ub_from_array(double *ubs) override;
+  void
+  set_bounds_in_array(double new_lb, double new_ub, double *lbs, double *ubs,
+                      double feasibility_tol, double integer_tol,
+                      double improvement_tol,
+                      std::set<std::shared_ptr<Var>> &improved_vars) override;
+};
+
+class Param : public Leaf {
+public:
+  Param() = default;
+  Param(double val) : Leaf(val) {}
+  Param(std::string _name) : name(_name) {}
+  Param(std::string _name, double val) : Leaf(val), name(_name) {}
+  std::string name = "p";
+  std::string __str__() override;
+  bool is_param_type() override;
+  int get_degree_from_array(int *) override;
+  std::shared_ptr<std::vector<std::shared_ptr<Var>>>
+  identify_variables() override;
+  std::shared_ptr<std::vector<std::shared_ptr<ExternalOperator>>>
+  identify_external_operators() override;
+  void write_nl_string(std::ofstream &) override;
+};
+
+class Expression : public ExpressionBase {
+public:
+  Expression(int _n_operators) : ExpressionBase() {
+    operators = new std::shared_ptr<Operator>[_n_operators];
+    n_operators = _n_operators;
+  }
+  ~Expression() { delete[] operators; }
+  std::string __str__() override;
+  bool is_expression_type() override;
+  double evaluate() override;
+  double get_value_from_array(double *) override;
+  int get_degree_from_array(int *) override;
+  std::shared_ptr<std::vector<std::shared_ptr<Var>>>
+  identify_variables() override;
+  std::shared_ptr<std::vector<std::shared_ptr<ExternalOperator>>>
+  identify_external_operators() override;
+  std::string get_string_from_array(std::string *) override;
+  std::shared_ptr<std::vector<std::shared_ptr<Node>>>
+  get_prefix_notation() override;
+  void write_nl_string(std::ofstream &) override;
+  std::vector<std::shared_ptr<Operator>> get_operators();
+  std::shared_ptr<Operator> *operators;
+  unsigned int n_operators;
+  void fill_expression(std::shared_ptr<Operator> *oper_array,
+                       int &oper_ndx) override;
+  void propagate_bounds_forward(double *lbs, double *ubs,
+                                double feasibility_tol, double integer_tol);
+  void propagate_bounds_backward(double *lbs, double *ubs,
+                                 double feasibility_tol, double integer_tol,
+                                 double improvement_tol,
+                                 std::set<std::shared_ptr<Var>> &improved_vars);
+  double get_lb_from_array(double *lbs) override;
+  double get_ub_from_array(double *ubs) override;
+  void
+  set_bounds_in_array(double new_lb, double new_ub, double *lbs, double *ubs,
+                      double feasibility_tol, double integer_tol,
+                      double improvement_tol,
+                      std::set<std::shared_ptr<Var>> &improved_vars) override;
+};
+
+class Operator : public Node {
+public:
+  Operator() = default;
+  int index = 0;
+  virtual void evaluate(double *values) = 0;
+  virtual void propagate_degree_forward(int *degrees, double *values) = 0;
+  virtual void
+  identify_variables(std::set<std::shared_ptr<Node>> &,
+                     std::shared_ptr<std::vector<std::shared_ptr<Var>>>) = 0;
+  std::shared_ptr<Operator> shared_from_this() {
+    return std::static_pointer_cast<Operator>(Node::shared_from_this());
+  }
+  bool is_operator_type() override;
+  double get_value_from_array(double *) override;
+  int get_degree_from_array(int *) override;
+  std::string get_string_from_array(std::string *) override;
+  virtual void print(std::string *) = 0;
+  virtual std::string name() = 0;
+  virtual void propagate_bounds_forward(double *lbs, double *ubs,
+                                        double feasibility_tol,
+                                        double integer_tol);
+  virtual void
+  propagate_bounds_backward(double *lbs, double *ubs, double feasibility_tol,
+                            double integer_tol, double improvement_tol,
+                            std::set<std::shared_ptr<Var>> &improved_vars);
+  double get_lb_from_array(double *lbs) override;
+  double get_ub_from_array(double *ubs) override;
+  void
+  set_bounds_in_array(double new_lb, double new_ub, double *lbs, double *ubs,
+                      double feasibility_tol, double integer_tol,
+                      double improvement_tol,
+                      std::set<std::shared_ptr<Var>> &improved_vars) override;
+};
+
+class BinaryOperator : public Operator {
+public:
+  BinaryOperator() = default;
+  virtual ~BinaryOperator() = default;
+  void identify_variables(
+      std::set<std::shared_ptr<Node>> &,
+      std::shared_ptr<std::vector<std::shared_ptr<Var>>>) override;
+  std::shared_ptr<Node> operand1;
+  std::shared_ptr<Node> operand2;
+  void fill_prefix_notation_stack(
+      std::shared_ptr<std::vector<std::shared_ptr<Node>>> stack) override;
+  bool is_binary_operator() override;
+  void fill_expression(std::shared_ptr<Operator> *oper_array,
+                       int &oper_ndx) override;
+};
+
+class UnaryOperator : public Operator {
+public:
+  UnaryOperator() = default;
+  virtual ~UnaryOperator() = default;
+  void identify_variables(
+      std::set<std::shared_ptr<Node>> &,
+      std::shared_ptr<std::vector<std::shared_ptr<Var>>>) override;
+  std::shared_ptr<Node> operand;
+  void fill_prefix_notation_stack(
+      std::shared_ptr<std::vector<std::shared_ptr<Node>>> stack) override;
+  bool is_unary_operator() override;
+  void propagate_degree_forward(int *degrees, double *values) override;
+  void fill_expression(std::shared_ptr<Operator> *oper_array,
+                       int &oper_ndx) override;
+};
+
+class LinearOperator : public Operator {
+public:
+  LinearOperator(int _nterms) {
+    variables = new std::shared_ptr<Var>[_nterms];
+    coefficients = new std::shared_ptr<ExpressionBase>[_nterms];
+    nterms = _nterms;
+  }
+  ~LinearOperator() {
+    delete[] variables;
+    delete[] coefficients;
+  }
+  void identify_variables(
+      std::set<std::shared_ptr<Node>> &,
+      std::shared_ptr<std::vector<std::shared_ptr<Var>>>) override;
+  std::shared_ptr<Var> *variables;
+  std::shared_ptr<ExpressionBase> *coefficients;
+  std::shared_ptr<ExpressionBase> constant = std::make_shared<Constant>(0);
+  void evaluate(double *values) override;
+  void propagate_degree_forward(int *degrees, double *values) override;
+  void print(std::string *) override;
+  std::string name() override { return "LinearOperator"; };
+  void write_nl_string(std::ofstream &) override;
+  void fill_prefix_notation_stack(
+      std::shared_ptr<std::vector<std::shared_ptr<Node>>> stack) override;
+  bool is_linear_operator() override;
+  unsigned int nterms;
+  void fill_expression(std::shared_ptr<Operator> *oper_array,
+                       int &oper_ndx) override;
+  void propagate_bounds_forward(double *lbs, double *ubs,
+                                double feasibility_tol,
+                                double integer_tol) override;
+  void propagate_bounds_backward(
+      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+      double improvement_tol,
+      std::set<std::shared_ptr<Var>> &improved_vars) override;
+};
+
+class SumOperator : public Operator {
+public:
+  SumOperator(int _nargs) {
+    operands = new std::shared_ptr<Node>[_nargs];
+    nargs = _nargs;
+  }
+  ~SumOperator() { delete[] operands; }
+  void identify_variables(
+      std::set<std::shared_ptr<Node>> &,
+      std::shared_ptr<std::vector<std::shared_ptr<Var>>>) override;
+  void evaluate(double *values) override;
+  void propagate_degree_forward(int *degrees, double *values) override;
+  void print(std::string *) override;
+  std::string name() override { return "SumOperator"; };
+  void write_nl_string(std::ofstream &) override;
+  void fill_prefix_notation_stack(
+      std::shared_ptr<std::vector<std::shared_ptr<Node>>> stack) override;
+  bool is_sum_operator() override;
+  std::shared_ptr<Node> *operands;
+  unsigned int nargs;
+  void fill_expression(std::shared_ptr<Operator> *oper_array,
+                       int &oper_ndx) override;
+  void propagate_bounds_forward(double *lbs, double *ubs,
+                                double feasibility_tol,
+                                double integer_tol) override;
+  void propagate_bounds_backward(
+      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+      double improvement_tol,
+      std::set<std::shared_ptr<Var>> &improved_vars) override;
+};
+
+class MultiplyOperator : public BinaryOperator {
+public:
+  MultiplyOperator() = default;
+  void evaluate(double *values) override;
+  void propagate_degree_forward(int *degrees, double *values) override;
+  void print(std::string *) override;
+  std::string name() override { return "MultiplyOperator"; };
+  void write_nl_string(std::ofstream &) override;
+  bool is_multiply_operator() override;
+  void propagate_bounds_forward(double *lbs, double *ubs,
+                                double feasibility_tol,
+                                double integer_tol) override;
+  void propagate_bounds_backward(
+      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+      double improvement_tol,
+      std::set<std::shared_ptr<Var>> &improved_vars) override;
+};
+
+class ExternalOperator : public Operator {
+public:
+  ExternalOperator(int _nargs) {
+    operands = new std::shared_ptr<Node>[_nargs];
+    nargs = _nargs;
+  }
+  ~ExternalOperator() { delete[] operands; }
+  void evaluate(double *values) override;
+  void propagate_degree_forward(int *degrees, double *values) override;
+  void print(std::string *) override;
+  std::string name() override { return "ExternalOperator"; };
+  void write_nl_string(std::ofstream &) override;
+  void fill_prefix_notation_stack(
+      std::shared_ptr<std::vector<std::shared_ptr<Node>>> stack) override;
+  void identify_variables(
+      std::set<std::shared_ptr<Node>> &,
+      std::shared_ptr<std::vector<std::shared_ptr<Var>>>) override;
+  bool is_external_operator() override;
+  std::string function_name;
+  int external_function_index = -1;
+  std::shared_ptr<Node> *operands;
+  unsigned int nargs;
+  void fill_expression(std::shared_ptr<Operator> *oper_array,
+                       int &oper_ndx) override;
+};
+
+class DivideOperator : public BinaryOperator {
+public:
+  DivideOperator() = default;
+  void evaluate(double *values) override;
+  void propagate_degree_forward(int *degrees, double *values) override;
+  void print(std::string *) override;
+  std::string name() override { return "DivideOperator"; };
+  void write_nl_string(std::ofstream &) override;
+  bool is_divide_operator() override;
+  void propagate_bounds_forward(double *lbs, double *ubs,
+                                double feasibility_tol,
+                                double integer_tol) override;
+  void propagate_bounds_backward(
+      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+      double improvement_tol,
+      std::set<std::shared_ptr<Var>> &improved_vars) override;
+};
+
+class PowerOperator : public BinaryOperator {
+public:
+  PowerOperator() = default;
+  void evaluate(double *values) override;
+  void propagate_degree_forward(int *degrees, double *values) override;
+  void print(std::string *) override;
+  std::string name() override { return "PowerOperator"; };
+  void write_nl_string(std::ofstream &) override;
+  bool is_power_operator() override;
+  void propagate_bounds_forward(double *lbs, double *ubs,
+                                double feasibility_tol,
+                                double integer_tol) override;
+  void propagate_bounds_backward(
+      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+      double improvement_tol,
+      std::set<std::shared_ptr<Var>> &improved_vars) override;
+};
+
+class NegationOperator : public UnaryOperator {
+public:
+  NegationOperator() = default;
+  void evaluate(double *values) override;
+  void propagate_degree_forward(int *degrees, double *values) override;
+  void print(std::string *) override;
+  std::string name() override { return "NegationOperator"; };
+  void write_nl_string(std::ofstream &) override;
+  bool is_negation_operator() override;
+  void propagate_bounds_forward(double *lbs, double *ubs,
+                                double feasibility_tol,
+                                double integer_tol) override;
+  void propagate_bounds_backward(
+      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+      double improvement_tol,
+      std::set<std::shared_ptr<Var>> &improved_vars) override;
+};
+
+class ExpOperator : public UnaryOperator {
+public:
+  ExpOperator() = default;
+  void evaluate(double *values) override;
+  void print(std::string *) override;
+  std::string name() override { return "ExpOperator"; };
+  void write_nl_string(std::ofstream &) override;
+  bool is_exp_operator() override;
+  void propagate_bounds_forward(double *lbs, double *ubs,
+                                double feasibility_tol,
+                                double integer_tol) override;
+  void propagate_bounds_backward(
+      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+      double improvement_tol,
+      std::set<std::shared_ptr<Var>> &improved_vars) override;
+};
+
+class LogOperator : public UnaryOperator {
+public:
+  LogOperator() = default;
+  void evaluate(double *values) override;
+  void print(std::string *) override;
+  std::string name() override { return "LogOperator"; };
+  void write_nl_string(std::ofstream &) override;
+  bool is_log_operator() override;
+  void propagate_bounds_forward(double *lbs, double *ubs,
+                                double feasibility_tol,
+                                double integer_tol) override;
+  void propagate_bounds_backward(
+      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+      double improvement_tol,
+      std::set<std::shared_ptr<Var>> &improved_vars) override;
+};
+
+class AbsOperator : public UnaryOperator {
+public:
+  AbsOperator() = default;
+  void evaluate(double *values) override;
+  void print(std::string *) override;
+  std::string name() override { return "AbsOperator"; };
+  void write_nl_string(std::ofstream &) override;
+  bool is_abs_operator() override;
+  void propagate_bounds_forward(double *lbs, double *ubs,
+                                double feasibility_tol,
+                                double integer_tol) override;
+  void propagate_bounds_backward(
+      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+      double improvement_tol,
+      std::set<std::shared_ptr<Var>> &improved_vars) override;
+};
+
+class SqrtOperator : public UnaryOperator {
+public:
+  SqrtOperator() = default;
+  void evaluate(double *values) override;
+  void print(std::string *) override;
+  std::string name() override { return "SqrtOperator"; };
+  void write_nl_string(std::ofstream &) override;
+  bool is_sqrt_operator() override;
+  void propagate_bounds_forward(double *lbs, double *ubs,
+                                double feasibility_tol,
+                                double integer_tol) override;
+  void propagate_bounds_backward(
+      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+      double improvement_tol,
+      std::set<std::shared_ptr<Var>> &improved_vars) override;
+};
+
+class Log10Operator : public UnaryOperator {
+public:
+  Log10Operator() = default;
+  void evaluate(double *values) override;
+  void print(std::string *) override;
+  std::string name() override { return "Log10Operator"; };
+  void write_nl_string(std::ofstream &) override;
+  void propagate_bounds_forward(double *lbs, double *ubs,
+                                double feasibility_tol,
+                                double integer_tol) override;
+  void propagate_bounds_backward(
+      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+      double improvement_tol,
+      std::set<std::shared_ptr<Var>> &improved_vars) override;
+};
+
+class SinOperator : public UnaryOperator {
+public:
+  SinOperator() = default;
+  void evaluate(double *values) override;
+  void print(std::string *) override;
+  std::string name() override { return "SinOperator"; };
+  void write_nl_string(std::ofstream &) override;
+  void propagate_bounds_forward(double *lbs, double *ubs,
+                                double feasibility_tol,
+                                double integer_tol) override;
+  void propagate_bounds_backward(
+      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+      double improvement_tol,
+      std::set<std::shared_ptr<Var>> &improved_vars) override;
+};
+
+class CosOperator : public UnaryOperator {
+public:
+  CosOperator() = default;
+  void evaluate(double *values) override;
+  void print(std::string *) override;
+  std::string name() override { return "CosOperator"; };
+  void write_nl_string(std::ofstream &) override;
+  void propagate_bounds_forward(double *lbs, double *ubs,
+                                double feasibility_tol,
+                                double integer_tol) override;
+  void propagate_bounds_backward(
+      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+      double improvement_tol,
+      std::set<std::shared_ptr<Var>> &improved_vars) override;
+};
+
+class TanOperator : public UnaryOperator {
+public:
+  TanOperator() = default;
+  void evaluate(double *values) override;
+  void print(std::string *) override;
+  std::string name() override { return "TanOperator"; };
+  void write_nl_string(std::ofstream &) override;
+  void propagate_bounds_forward(double *lbs, double *ubs,
+                                double feasibility_tol,
+                                double integer_tol) override;
+  void propagate_bounds_backward(
+      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+      double improvement_tol,
+      std::set<std::shared_ptr<Var>> &improved_vars) override;
+};
+
+class AsinOperator : public UnaryOperator {
+public:
+  AsinOperator() = default;
+  void evaluate(double *values) override;
+  void print(std::string *) override;
+  std::string name() override { return "AsinOperator"; };
+  void write_nl_string(std::ofstream &) override;
+  void propagate_bounds_forward(double *lbs, double *ubs,
+                                double feasibility_tol,
+                                double integer_tol) override;
+  void propagate_bounds_backward(
+      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+      double improvement_tol,
+      std::set<std::shared_ptr<Var>> &improved_vars) override;
+};
+
+class AcosOperator : public UnaryOperator {
+public:
+  AcosOperator() = default;
+  void evaluate(double *values) override;
+  void print(std::string *) override;
+  std::string name() override { return "AcosOperator"; };
+  void write_nl_string(std::ofstream &) override;
+  void propagate_bounds_forward(double *lbs, double *ubs,
+                                double feasibility_tol,
+                                double integer_tol) override;
+  void propagate_bounds_backward(
+      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+      double improvement_tol,
+      std::set<std::shared_ptr<Var>> &improved_vars) override;
+};
+
+class AtanOperator : public UnaryOperator {
+public:
+  AtanOperator() = default;
+  void evaluate(double *values) override;
+  void print(std::string *) override;
+  std::string name() override { return "AtanOperator"; };
+  void write_nl_string(std::ofstream &) override;
+  void propagate_bounds_forward(double *lbs, double *ubs,
+                                double feasibility_tol,
+                                double integer_tol) override;
+  void propagate_bounds_backward(
+      double *lbs, double *ubs, double feasibility_tol, double integer_tol,
+      double improvement_tol,
+      std::set<std::shared_ptr<Var>> &improved_vars) override;
+};
+
+enum ExprType {
+  py_float = 0,
+  var = 1,
+  param = 2,
+  product = 3,
+  sum = 4,
+  negation = 5,
+  external_func = 6,
+  power = 7,
+  division = 8,
+  unary_func = 9,
+  linear = 10,
+  named_expr = 11,
+  numeric_constant = 12,
+  pyomo_unit = 13,
+  unary_abs = 14
+};
+
+class PyomoExprTypes {
+public:
+  PyomoExprTypes() {
+    expr_type_map[int_] = py_float;
+    expr_type_map[float_] = py_float;
+    expr_type_map[np_int16] = py_float;
+    expr_type_map[np_int32] = py_float;
+    expr_type_map[np_int64] = py_float;
+    expr_type_map[np_longlong] = py_float;
+    expr_type_map[np_uint16] = py_float;
+    expr_type_map[np_uint32] = py_float;
+    expr_type_map[np_uint64] = py_float;
+    expr_type_map[np_ulonglong] = py_float;
+    expr_type_map[np_float16] = py_float;
+    expr_type_map[np_float32] = py_float;
+    expr_type_map[np_float64] = py_float;
+    expr_type_map[ScalarVar] = var;
+    expr_type_map[VarData] = var;
+    expr_type_map[AutoLinkedBinaryVar] = var;
+    expr_type_map[ScalarParam] = param;
+    expr_type_map[ParamData] = param;
+    expr_type_map[MonomialTermExpression] = product;
+    expr_type_map[ProductExpression] = product;
+    expr_type_map[NPV_ProductExpression] = product;
+    expr_type_map[SumExpression] = sum;
+    expr_type_map[NPV_SumExpression] = sum;
+    expr_type_map[NegationExpression] = negation;
+    expr_type_map[NPV_NegationExpression] = negation;
+    expr_type_map[ExternalFunctionExpression] = external_func;
+    expr_type_map[NPV_ExternalFunctionExpression] = external_func;
+    expr_type_map[PowExpression] = power;
+    expr_type_map[NPV_PowExpression] = power;
+    expr_type_map[DivisionExpression] = division;
+    expr_type_map[NPV_DivisionExpression] = division;
+    expr_type_map[UnaryFunctionExpression] = unary_func;
+    expr_type_map[NPV_UnaryFunctionExpression] = unary_func;
+    expr_type_map[LinearExpression] = linear;
+    expr_type_map[ExpressionData] = named_expr;
+    expr_type_map[ScalarExpression] = named_expr;
+    expr_type_map[Integral] = named_expr;
+    expr_type_map[ScalarIntegral] = named_expr;
+    expr_type_map[NumericConstant] = numeric_constant;
+    expr_type_map[_PyomoUnit] = pyomo_unit;
+    expr_type_map[AbsExpression] = unary_abs;
+    expr_type_map[NPV_AbsExpression] = unary_abs;
+  }
+  ~PyomoExprTypes() = default;
+  py::int_ ione = 1;
+  py::float_ fone = 1.0;
+  py::type int_ = py::type::of(ione);
+  py::type float_ = py::type::of(fone);
+  py::object np = py::module_::import("numpy");
+  py::type np_int16 = np.attr("int16");
+  py::type np_int32 = np.attr("int32");
+  py::type np_int64 = np.attr("int64");
+  py::type np_longlong = np.attr("longlong");
+  py::type np_uint16 = np.attr("uint16");
+  py::type np_uint32 = np.attr("uint32");
+  py::type np_uint64 = np.attr("uint64");
+  py::type np_ulonglong = np.attr("ulonglong");
+  py::type np_float16 = np.attr("float16");
+  py::type np_float32 = np.attr("float32");
+  py::type np_float64 = np.attr("float64");
+  py::object ScalarParam =
+      py::module_::import("pyomo.core.base.param").attr("ScalarParam");
+  py::object ParamData =
+      py::module_::import("pyomo.core.base.param").attr("ParamData");
+  py::object ScalarVar =
+      py::module_::import("pyomo.core.base.var").attr("ScalarVar");
+  py::object VarData =
+      py::module_::import("pyomo.core.base.var").attr("VarData");
+  py::object AutoLinkedBinaryVar =
+      py::module_::import("pyomo.gdp.disjunct").attr("AutoLinkedBinaryVar");
+  py::object numeric_expr = py::module_::import("pyomo.core.expr.numeric_expr");
+  py::object NegationExpression = numeric_expr.attr("NegationExpression");
+  py::object NPV_NegationExpression =
+      numeric_expr.attr("NPV_NegationExpression");
+  py::object ExternalFunctionExpression =
+      numeric_expr.attr("ExternalFunctionExpression");
+  py::object NPV_ExternalFunctionExpression =
+      numeric_expr.attr("NPV_ExternalFunctionExpression");
+  py::object PowExpression = numeric_expr.attr("PowExpression");
+  py::object NPV_PowExpression = numeric_expr.attr("NPV_PowExpression");
+  py::object ProductExpression = numeric_expr.attr("ProductExpression");
+  py::object NPV_ProductExpression = numeric_expr.attr("NPV_ProductExpression");
+  py::object MonomialTermExpression =
+      numeric_expr.attr("MonomialTermExpression");
+  py::object DivisionExpression = numeric_expr.attr("DivisionExpression");
+  py::object NPV_DivisionExpression =
+      numeric_expr.attr("NPV_DivisionExpression");
+  py::object SumExpression = numeric_expr.attr("SumExpression");
+  py::object NPV_SumExpression = numeric_expr.attr("NPV_SumExpression");
+  py::object UnaryFunctionExpression =
+      numeric_expr.attr("UnaryFunctionExpression");
+  py::object AbsExpression = numeric_expr.attr("AbsExpression");
+  py::object NPV_AbsExpression = numeric_expr.attr("NPV_AbsExpression");
+  py::object NPV_UnaryFunctionExpression =
+      numeric_expr.attr("NPV_UnaryFunctionExpression");
+  py::object LinearExpression = numeric_expr.attr("LinearExpression");
+  py::object NumericConstant =
+      py::module_::import("pyomo.core.expr.numvalue").attr("NumericConstant");
+  py::object expr_module = py::module_::import("pyomo.core.base.expression");
+  py::object ExpressionData =
+      expr_module.attr("ExpressionData");
+  py::object ScalarExpression = expr_module.attr("ScalarExpression");
+  py::object ScalarIntegral =
+      py::module_::import("pyomo.dae.integral").attr("ScalarIntegral");
+  py::object Integral =
+      py::module_::import("pyomo.dae.integral").attr("Integral");
+  py::object _PyomoUnit =
+      py::module_::import("pyomo.core.base.units_container").attr("_PyomoUnit");
+  py::object builtins = py::module_::import("builtins");
+  py::object id = builtins.attr("id");
+  py::object len = builtins.attr("len");
+  py::dict expr_type_map;
+};
+
+std::vector<std::shared_ptr<Var>> create_vars(int n_vars);
+std::vector<std::shared_ptr<Param>> create_params(int n_params);
+std::vector<std::shared_ptr<Constant>> create_constants(int n_constants);
+std::shared_ptr<ExpressionBase>
+appsi_expr_from_pyomo_expr(py::handle expr, py::handle var_map,
+                           py::handle param_map, PyomoExprTypes &expr_types);
+std::vector<std::shared_ptr<ExpressionBase>>
+appsi_exprs_from_pyomo_exprs(py::list expr_list, py::dict var_map,
+                             py::dict param_map);
+py::tuple prep_for_repn(py::handle expr, PyomoExprTypes &expr_types);
+
+void process_pyomo_vars(PyomoExprTypes &expr_types, py::list pyomo_vars,
+                        py::dict var_map, py::dict param_map,
+                        py::dict var_attrs, py::dict rev_var_map,
+                        py::bool_ _set_name, py::handle symbol_map,
+                        py::handle labeler, py::bool_ _update);
+
+#endif
diff --git a/pyomo/contrib/appsi/cmodel/src/fbbt_model.cpp b/pyomo/contrib/appsi/cmodel/src/fbbt_model.cpp
index 2e490659fab..bd8d7dbf854 100644
--- a/pyomo/contrib/appsi/cmodel/src/fbbt_model.cpp
+++ b/pyomo/contrib/appsi/cmodel/src/fbbt_model.cpp
@@ -1,3 +1,15 @@
+/**___________________________________________________________________________
+ *
+ * Pyomo: Python Optimization Modeling Objects
+ * Copyright (c) 2008-2024
+ * National Technology and Engineering Solutions of Sandia, LLC
+ * Under the terms of Contract DE-NA0003525 with National Technology and
+ * Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+ * rights in this software.
+ * This software is distributed under the 3-clause BSD License.
+ * ___________________________________________________________________________
+**/
+
 #include "fbbt_model.hpp"
 
 FBBTObjective::FBBTObjective(std::shared_ptr<ExpressionBase> _expr)
diff --git a/pyomo/contrib/appsi/cmodel/src/fbbt_model.hpp b/pyomo/contrib/appsi/cmodel/src/fbbt_model.hpp
index 3d1c3a76caa..ca1980a797b 100644
--- a/pyomo/contrib/appsi/cmodel/src/fbbt_model.hpp
+++ b/pyomo/contrib/appsi/cmodel/src/fbbt_model.hpp
@@ -1,3 +1,15 @@
+/**___________________________________________________________________________
+ *
+ * Pyomo: Python Optimization Modeling Objects
+ * Copyright (c) 2008-2024
+ * National Technology and Engineering Solutions of Sandia, LLC
+ * Under the terms of Contract DE-NA0003525 with National Technology and
+ * Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+ * rights in this software.
+ * This software is distributed under the 3-clause BSD License.
+ * ___________________________________________________________________________
+**/
+
 #include "model_base.hpp"
 
 class FBBTConstraint;
diff --git a/pyomo/contrib/appsi/cmodel/src/interval.cpp b/pyomo/contrib/appsi/cmodel/src/interval.cpp
index f0a1aa2c2bb..1d9b3a6f82e 100644
--- a/pyomo/contrib/appsi/cmodel/src/interval.cpp
+++ b/pyomo/contrib/appsi/cmodel/src/interval.cpp
@@ -1,3 +1,15 @@
+/**___________________________________________________________________________
+ *
+ * Pyomo: Python Optimization Modeling Objects
+ * Copyright (c) 2008-2024
+ * National Technology and Engineering Solutions of Sandia, LLC
+ * Under the terms of Contract DE-NA0003525 with National Technology and
+ * Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+ * rights in this software.
+ * This software is distributed under the 3-clause BSD License.
+ * ___________________________________________________________________________
+**/
+
 #include "interval.hpp"
 
 bool _is_inf(double x) {
diff --git a/pyomo/contrib/appsi/cmodel/src/interval.hpp b/pyomo/contrib/appsi/cmodel/src/interval.hpp
index c35438887dd..a57f107f8db 100644
--- a/pyomo/contrib/appsi/cmodel/src/interval.hpp
+++ b/pyomo/contrib/appsi/cmodel/src/interval.hpp
@@ -1,3 +1,15 @@
+/**___________________________________________________________________________
+ *
+ * Pyomo: Python Optimization Modeling Objects
+ * Copyright (c) 2008-2024
+ * National Technology and Engineering Solutions of Sandia, LLC
+ * Under the terms of Contract DE-NA0003525 with National Technology and
+ * Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+ * rights in this software.
+ * This software is distributed under the 3-clause BSD License.
+ * ___________________________________________________________________________
+**/
+
 #ifndef INTERVAL_HEADER
 #define INTERVAL_HEADER
 
diff --git a/pyomo/contrib/appsi/cmodel/src/lp_writer.cpp b/pyomo/contrib/appsi/cmodel/src/lp_writer.cpp
index 1ce421b7c97..68baf2b8ae8 100644
--- a/pyomo/contrib/appsi/cmodel/src/lp_writer.cpp
+++ b/pyomo/contrib/appsi/cmodel/src/lp_writer.cpp
@@ -1,3 +1,15 @@
+/**___________________________________________________________________________
+ *
+ * Pyomo: Python Optimization Modeling Objects
+ * Copyright (c) 2008-2024
+ * National Technology and Engineering Solutions of Sandia, LLC
+ * Under the terms of Contract DE-NA0003525 with National Technology and
+ * Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+ * rights in this software.
+ * This software is distributed under the 3-clause BSD License.
+ * ___________________________________________________________________________
+**/
+
 #include "lp_writer.hpp"
 
 void write_expr(std::ofstream &f, std::shared_ptr<LPBase> obj,
diff --git a/pyomo/contrib/appsi/cmodel/src/lp_writer.hpp b/pyomo/contrib/appsi/cmodel/src/lp_writer.hpp
index ee4ad77500a..0b2e2882510 100644
--- a/pyomo/contrib/appsi/cmodel/src/lp_writer.hpp
+++ b/pyomo/contrib/appsi/cmodel/src/lp_writer.hpp
@@ -1,3 +1,15 @@
+/**___________________________________________________________________________
+ *
+ * Pyomo: Python Optimization Modeling Objects
+ * Copyright (c) 2008-2024
+ * National Technology and Engineering Solutions of Sandia, LLC
+ * Under the terms of Contract DE-NA0003525 with National Technology and
+ * Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+ * rights in this software.
+ * This software is distributed under the 3-clause BSD License.
+ * ___________________________________________________________________________
+**/
+
 #include "model_base.hpp"
 
 class LPBase;
diff --git a/pyomo/contrib/appsi/cmodel/src/model_base.cpp b/pyomo/contrib/appsi/cmodel/src/model_base.cpp
index ab0b25d8e0d..b0ae4013b32 100644
--- a/pyomo/contrib/appsi/cmodel/src/model_base.cpp
+++ b/pyomo/contrib/appsi/cmodel/src/model_base.cpp
@@ -1,3 +1,15 @@
+/**___________________________________________________________________________
+ *
+ * Pyomo: Python Optimization Modeling Objects
+ * Copyright (c) 2008-2024
+ * National Technology and Engineering Solutions of Sandia, LLC
+ * Under the terms of Contract DE-NA0003525 with National Technology and
+ * Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+ * rights in this software.
+ * This software is distributed under the 3-clause BSD License.
+ * ___________________________________________________________________________
+**/
+
 #include "model_base.hpp"
 
 bool constraint_sorter(std::shared_ptr<Constraint> c1,
diff --git a/pyomo/contrib/appsi/cmodel/src/model_base.hpp b/pyomo/contrib/appsi/cmodel/src/model_base.hpp
index bc61bc053de..a47f1d14a0b 100644
--- a/pyomo/contrib/appsi/cmodel/src/model_base.hpp
+++ b/pyomo/contrib/appsi/cmodel/src/model_base.hpp
@@ -1,3 +1,15 @@
+/**___________________________________________________________________________
+ *
+ * Pyomo: Python Optimization Modeling Objects
+ * Copyright (c) 2008-2024
+ * National Technology and Engineering Solutions of Sandia, LLC
+ * Under the terms of Contract DE-NA0003525 with National Technology and
+ * Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+ * rights in this software.
+ * This software is distributed under the 3-clause BSD License.
+ * ___________________________________________________________________________
+**/
+
 #ifndef MODEL_HEADER
 #define MODEL_HEADER
 
diff --git a/pyomo/contrib/appsi/cmodel/src/nl_writer.cpp b/pyomo/contrib/appsi/cmodel/src/nl_writer.cpp
index dc7004abc16..8de6cc74ab4 100644
--- a/pyomo/contrib/appsi/cmodel/src/nl_writer.cpp
+++ b/pyomo/contrib/appsi/cmodel/src/nl_writer.cpp
@@ -1,3 +1,15 @@
+/**___________________________________________________________________________
+ *
+ * Pyomo: Python Optimization Modeling Objects
+ * Copyright (c) 2008-2024
+ * National Technology and Engineering Solutions of Sandia, LLC
+ * Under the terms of Contract DE-NA0003525 with National Technology and
+ * Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+ * rights in this software.
+ * This software is distributed under the 3-clause BSD License.
+ * ___________________________________________________________________________
+**/
+
 #include "nl_writer.hpp"
 
 NLBase::NLBase(
diff --git a/pyomo/contrib/appsi/cmodel/src/nl_writer.hpp b/pyomo/contrib/appsi/cmodel/src/nl_writer.hpp
index 40e4c9b1222..b7439875301 100644
--- a/pyomo/contrib/appsi/cmodel/src/nl_writer.hpp
+++ b/pyomo/contrib/appsi/cmodel/src/nl_writer.hpp
@@ -1,3 +1,15 @@
+/**___________________________________________________________________________
+ *
+ * Pyomo: Python Optimization Modeling Objects
+ * Copyright (c) 2008-2024
+ * National Technology and Engineering Solutions of Sandia, LLC
+ * Under the terms of Contract DE-NA0003525 with National Technology and
+ * Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+ * rights in this software.
+ * This software is distributed under the 3-clause BSD License.
+ * ___________________________________________________________________________
+**/
+
 #include "model_base.hpp"
 
 class NLBase;
diff --git a/pyomo/contrib/appsi/cmodel/tests/__init__.py b/pyomo/contrib/appsi/cmodel/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/appsi/cmodel/tests/__init__.py
+++ b/pyomo/contrib/appsi/cmodel/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/appsi/cmodel/tests/test_import.py b/pyomo/contrib/appsi/cmodel/tests/test_import.py
index f4647c216ba..76eda902ac0 100644
--- a/pyomo/contrib/appsi/cmodel/tests/test_import.py
+++ b/pyomo/contrib/appsi/cmodel/tests/test_import.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.common import unittest
 from pyomo.common.fileutils import find_library, this_file_dir
 import os
diff --git a/pyomo/contrib/appsi/examples/__init__.py b/pyomo/contrib/appsi/examples/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/appsi/examples/__init__.py
+++ b/pyomo/contrib/appsi/examples/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/appsi/examples/getting_started.py b/pyomo/contrib/appsi/examples/getting_started.py
index de22d28e0a4..6bc42d1d377 100644
--- a/pyomo/contrib/appsi/examples/getting_started.py
+++ b/pyomo/contrib/appsi/examples/getting_started.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pe
 from pyomo.contrib import appsi
 from pyomo.common.timing import HierarchicalTimer
diff --git a/pyomo/contrib/appsi/examples/tests/__init__.py b/pyomo/contrib/appsi/examples/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/appsi/examples/tests/__init__.py
+++ b/pyomo/contrib/appsi/examples/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/appsi/examples/tests/test_examples.py b/pyomo/contrib/appsi/examples/tests/test_examples.py
index d2c88224a7d..a7608d36b98 100644
--- a/pyomo/contrib/appsi/examples/tests/test_examples.py
+++ b/pyomo/contrib/appsi/examples/tests/test_examples.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.contrib.appsi.examples import getting_started
 import pyomo.common.unittest as unittest
 import pyomo.environ as pe
diff --git a/pyomo/contrib/appsi/fbbt.py b/pyomo/contrib/appsi/fbbt.py
index 92a0e0c8cbc..8e0c74b00e9 100644
--- a/pyomo/contrib/appsi/fbbt.py
+++ b/pyomo/contrib/appsi/fbbt.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.contrib.appsi.base import PersistentBase
 from pyomo.common.config import (
     ConfigDict,
@@ -7,12 +18,12 @@
 )
 from .cmodel import cmodel, cmodel_available
 from typing import List, Optional
-from pyomo.core.base.var import _GeneralVarData
-from pyomo.core.base.param import _ParamData
-from pyomo.core.base.constraint import _GeneralConstraintData
-from pyomo.core.base.sos import _SOSConstraintData
-from pyomo.core.base.objective import _GeneralObjectiveData, minimize, maximize
-from pyomo.core.base.block import _BlockData
+from pyomo.core.base.var import VarData
+from pyomo.core.base.param import ParamData
+from pyomo.core.base.constraint import ConstraintData
+from pyomo.core.base.sos import SOSConstraintData
+from pyomo.core.base.objective import ObjectiveData, minimize, maximize
+from pyomo.core.base.block import BlockData
 from pyomo.core.base import SymbolMap, TextLabeler
 from pyomo.common.errors import InfeasibleConstraintException
 
@@ -110,7 +121,7 @@ def set_instance(self, model, symbolic_solver_labels: Optional[bool] = None):
         if self._objective is None:
             self.set_objective(None)
 
-    def _add_variables(self, variables: List[_GeneralVarData]):
+    def _add_variables(self, variables: List[VarData]):
         if self._symbolic_solver_labels:
             set_name = True
             symbol_map = self._symbol_map
@@ -132,7 +143,7 @@ def _add_variables(self, variables: List[_GeneralVarData]):
             False,
         )
 
-    def _add_params(self, params: List[_ParamData]):
+    def _add_params(self, params: List[ParamData]):
         cparams = cmodel.create_params(len(params))
         for ndx, p in enumerate(params):
             cp = cparams[ndx]
@@ -143,7 +154,7 @@ def _add_params(self, params: List[_ParamData]):
                 cp = cparams[ndx]
                 cp.name = self._symbol_map.getSymbol(p, self._param_labeler)
 
-    def _add_constraints(self, cons: List[_GeneralConstraintData]):
+    def _add_constraints(self, cons: List[ConstraintData]):
         cmodel.process_fbbt_constraints(
             self._cmodel,
             self._pyomo_expr_types,
@@ -158,13 +169,13 @@ def _add_constraints(self, cons: List[_GeneralConstraintData]):
             for c, cc in self._con_map.items():
                 cc.name = self._symbol_map.getSymbol(c, self._con_labeler)
 
-    def _add_sos_constraints(self, cons: List[_SOSConstraintData]):
+    def _add_sos_constraints(self, cons: List[SOSConstraintData]):
         if len(cons) != 0:
             raise NotImplementedError(
                 'IntervalTightener does not support SOS constraints'
             )
 
-    def _remove_constraints(self, cons: List[_GeneralConstraintData]):
+    def _remove_constraints(self, cons: List[ConstraintData]):
         if self._symbolic_solver_labels:
             for c in cons:
                 self._symbol_map.removeSymbol(c)
@@ -173,13 +184,13 @@ def _remove_constraints(self, cons: List[_GeneralConstraintData]):
             self._cmodel.remove_constraint(cc)
             del self._rcon_map[cc]
 
-    def _remove_sos_constraints(self, cons: List[_SOSConstraintData]):
+    def _remove_sos_constraints(self, cons: List[SOSConstraintData]):
         if len(cons) != 0:
             raise NotImplementedError(
                 'IntervalTightener does not support SOS constraints'
             )
 
-    def _remove_variables(self, variables: List[_GeneralVarData]):
+    def _remove_variables(self, variables: List[VarData]):
         if self._symbolic_solver_labels:
             for v in variables:
                 self._symbol_map.removeSymbol(v)
@@ -187,14 +198,14 @@ def _remove_variables(self, variables: List[_GeneralVarData]):
             cvar = self._var_map.pop(id(v))
             del self._rvar_map[cvar]
 
-    def _remove_params(self, params: List[_ParamData]):
+    def _remove_params(self, params: List[ParamData]):
         if self._symbolic_solver_labels:
             for p in params:
                 self._symbol_map.removeSymbol(p)
         for p in params:
             del self._param_map[id(p)]
 
-    def _update_variables(self, variables: List[_GeneralVarData]):
+    def _update_variables(self, variables: List[VarData]):
         cmodel.process_pyomo_vars(
             self._pyomo_expr_types,
             variables,
@@ -213,13 +224,13 @@ def update_params(self):
             cp = self._param_map[p_id]
             cp.value = p.value
 
-    def set_objective(self, obj: _GeneralObjectiveData):
+    def set_objective(self, obj: ObjectiveData):
         if self._symbolic_solver_labels:
             if self._objective is not None:
                 self._symbol_map.removeSymbol(self._objective)
         super().set_objective(obj)
 
-    def _set_objective(self, obj: _GeneralObjectiveData):
+    def _set_objective(self, obj: ObjectiveData):
         if obj is None:
             ce = cmodel.Constant(0)
             sense = 0
@@ -264,7 +275,7 @@ def _deactivate_satisfied_cons(self):
             c.deactivate()
 
     def perform_fbbt(
-        self, model: _BlockData, symbolic_solver_labels: Optional[bool] = None
+        self, model: BlockData, symbolic_solver_labels: Optional[bool] = None
     ):
         if model is not self._model:
             self.set_instance(model, symbolic_solver_labels=symbolic_solver_labels)
@@ -293,7 +304,7 @@ def perform_fbbt(
             self._deactivate_satisfied_cons()
         return n_iter
 
-    def perform_fbbt_with_seed(self, model: _BlockData, seed_var: _GeneralVarData):
+    def perform_fbbt_with_seed(self, model: BlockData, seed_var: VarData):
         if model is not self._model:
             self.set_instance(model)
         else:
diff --git a/pyomo/contrib/appsi/plugins.py b/pyomo/contrib/appsi/plugins.py
index 5333158239e..3e1b639ce3b 100644
--- a/pyomo/contrib/appsi/plugins.py
+++ b/pyomo/contrib/appsi/plugins.py
@@ -1,23 +1,35 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.common.extensions import ExtensionBuilderFactory
 from .base import SolverFactory
-from .solvers import Gurobi, Ipopt, Cbc, Cplex, Highs
+from .solvers import Gurobi, Ipopt, Cbc, Cplex, Highs, MAiNGO
 from .build import AppsiBuilder
 
 
 def load():
     ExtensionBuilderFactory.register('appsi')(AppsiBuilder)
     SolverFactory.register(
-        name='appsi_gurobi', doc='Automated persistent interface to Gurobi'
+        name='gurobi', doc='Automated persistent interface to Gurobi'
     )(Gurobi)
+    SolverFactory.register(name='cplex', doc='Automated persistent interface to Cplex')(
+        Cplex
+    )
+    SolverFactory.register(name='ipopt', doc='Automated persistent interface to Ipopt')(
+        Ipopt
+    )
+    SolverFactory.register(name='cbc', doc='Automated persistent interface to Cbc')(Cbc)
+    SolverFactory.register(name='highs', doc='Automated persistent interface to Highs')(
+        Highs
+    )
     SolverFactory.register(
-        name='appsi_cplex', doc='Automated persistent interface to Cplex'
-    )(Cplex)
-    SolverFactory.register(
-        name='appsi_ipopt', doc='Automated persistent interface to Ipopt'
-    )(Ipopt)
-    SolverFactory.register(
-        name='appsi_cbc', doc='Automated persistent interface to Cbc'
-    )(Cbc)
-    SolverFactory.register(
-        name='appsi_highs', doc='Automated persistent interface to Highs'
-    )(Highs)
+        name='maingo', doc='Automated persistent interface to MAiNGO'
+    )(MAiNGO)
diff --git a/pyomo/contrib/appsi/solvers/__init__.py b/pyomo/contrib/appsi/solvers/__init__.py
index 20755d1eb07..352571b98f8 100644
--- a/pyomo/contrib/appsi/solvers/__init__.py
+++ b/pyomo/contrib/appsi/solvers/__init__.py
@@ -1,6 +1,18 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from .gurobi import Gurobi, GurobiResults
 from .ipopt import Ipopt
 from .cbc import Cbc
 from .cplex import Cplex
 from .highs import Highs
 from .wntr import Wntr, WntrResults
+from .maingo import MAiNGO
diff --git a/pyomo/contrib/appsi/solvers/cbc.py b/pyomo/contrib/appsi/solvers/cbc.py
index a3aae2a9213..08833e747e2 100644
--- a/pyomo/contrib/appsi/solvers/cbc.py
+++ b/pyomo/contrib/appsi/solvers/cbc.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.common.tempfiles import TempfileManager
 from pyomo.common.fileutils import Executable
 from pyomo.contrib.appsi.base import (
@@ -15,11 +26,11 @@
 import math
 from pyomo.common.collections import ComponentMap
 from typing import Optional, Sequence, NoReturn, List, Mapping
-from pyomo.core.base.var import _GeneralVarData
-from pyomo.core.base.constraint import _GeneralConstraintData
-from pyomo.core.base.block import _BlockData
-from pyomo.core.base.param import _ParamData
-from pyomo.core.base.objective import _GeneralObjectiveData
+from pyomo.core.base.var import VarData
+from pyomo.core.base.constraint import ConstraintData
+from pyomo.core.base.block import BlockData
+from pyomo.core.base.param import ParamData
+from pyomo.core.base.objective import ObjectiveData
 from pyomo.common.timing import HierarchicalTimer
 from pyomo.common.tee import TeeStream
 import sys
@@ -153,34 +164,34 @@ def symbol_map(self):
     def set_instance(self, model):
         self._writer.set_instance(model)
 
-    def add_variables(self, variables: List[_GeneralVarData]):
+    def add_variables(self, variables: List[VarData]):
         self._writer.add_variables(variables)
 
-    def add_params(self, params: List[_ParamData]):
+    def add_params(self, params: List[ParamData]):
         self._writer.add_params(params)
 
-    def add_constraints(self, cons: List[_GeneralConstraintData]):
+    def add_constraints(self, cons: List[ConstraintData]):
         self._writer.add_constraints(cons)
 
-    def add_block(self, block: _BlockData):
+    def add_block(self, block: BlockData):
         self._writer.add_block(block)
 
-    def remove_variables(self, variables: List[_GeneralVarData]):
+    def remove_variables(self, variables: List[VarData]):
         self._writer.remove_variables(variables)
 
-    def remove_params(self, params: List[_ParamData]):
+    def remove_params(self, params: List[ParamData]):
         self._writer.remove_params(params)
 
-    def remove_constraints(self, cons: List[_GeneralConstraintData]):
+    def remove_constraints(self, cons: List[ConstraintData]):
         self._writer.remove_constraints(cons)
 
-    def remove_block(self, block: _BlockData):
+    def remove_block(self, block: BlockData):
         self._writer.remove_block(block)
 
-    def set_objective(self, obj: _GeneralObjectiveData):
+    def set_objective(self, obj: ObjectiveData):
         self._writer.set_objective(obj)
 
-    def update_variables(self, variables: List[_GeneralVarData]):
+    def update_variables(self, variables: List[VarData]):
         self._writer.update_variables(variables)
 
     def update_params(self):
@@ -400,9 +411,11 @@ def _check_and_escape_options():
         if cp.returncode != 0:
             if self.config.load_solution:
                 raise RuntimeError(
-                    'A feasible solution was not found, so no solution can be loaded.'
-                    'Please set opt.config.load_solution=False and check '
-                    'results.termination_condition and '
+                    'A feasible solution was not found, so no solution can be loaded. '
+                    'If using the appsi.solvers.Cbc interface, you can '
+                    'set opt.config.load_solution=False. If using the environ.SolverFactory '
+                    'interface, you can set opt.solve(model, load_solutions = False). '
+                    'Then you can check results.termination_condition and '
                     'results.best_feasible_objective before loading a solution.'
                 )
             results = Results()
@@ -427,8 +440,8 @@ def _check_and_escape_options():
         return results
 
     def get_primals(
-        self, vars_to_load: Optional[Sequence[_GeneralVarData]] = None
-    ) -> Mapping[_GeneralVarData, float]:
+        self, vars_to_load: Optional[Sequence[VarData]] = None
+    ) -> Mapping[VarData, float]:
         if (
             self._last_results_object is None
             or self._last_results_object.best_feasible_objective is None
@@ -464,8 +477,8 @@ def get_duals(self, cons_to_load=None):
             return {c: self._dual_sol[c] for c in cons_to_load}
 
     def get_reduced_costs(
-        self, vars_to_load: Optional[Sequence[_GeneralVarData]] = None
-    ) -> Mapping[_GeneralVarData, float]:
+        self, vars_to_load: Optional[Sequence[VarData]] = None
+    ) -> Mapping[VarData, float]:
         if (
             self._last_results_object is None
             or self._last_results_object.termination_condition
diff --git a/pyomo/contrib/appsi/solvers/cplex.py b/pyomo/contrib/appsi/solvers/cplex.py
index f03bee6ecc5..10de981ce7d 100644
--- a/pyomo/contrib/appsi/solvers/cplex.py
+++ b/pyomo/contrib/appsi/solvers/cplex.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.common.tempfiles import TempfileManager
 from pyomo.contrib.appsi.base import (
     PersistentSolver,
@@ -11,11 +22,11 @@
 import math
 from pyomo.common.collections import ComponentMap
 from typing import Optional, Sequence, NoReturn, List, Mapping, Dict
-from pyomo.core.base.var import _GeneralVarData
-from pyomo.core.base.constraint import _GeneralConstraintData
-from pyomo.core.base.block import _BlockData
-from pyomo.core.base.param import _ParamData
-from pyomo.core.base.objective import _GeneralObjectiveData
+from pyomo.core.base.var import VarData
+from pyomo.core.base.constraint import ConstraintData
+from pyomo.core.base.block import BlockData
+from pyomo.core.base.param import ParamData
+from pyomo.core.base.objective import ObjectiveData
 from pyomo.common.timing import HierarchicalTimer
 import sys
 import time
@@ -168,34 +179,34 @@ def update_config(self):
     def set_instance(self, model):
         self._writer.set_instance(model)
 
-    def add_variables(self, variables: List[_GeneralVarData]):
+    def add_variables(self, variables: List[VarData]):
         self._writer.add_variables(variables)
 
-    def add_params(self, params: List[_ParamData]):
+    def add_params(self, params: List[ParamData]):
         self._writer.add_params(params)
 
-    def add_constraints(self, cons: List[_GeneralConstraintData]):
+    def add_constraints(self, cons: List[ConstraintData]):
         self._writer.add_constraints(cons)
 
-    def add_block(self, block: _BlockData):
+    def add_block(self, block: BlockData):
         self._writer.add_block(block)
 
-    def remove_variables(self, variables: List[_GeneralVarData]):
+    def remove_variables(self, variables: List[VarData]):
         self._writer.remove_variables(variables)
 
-    def remove_params(self, params: List[_ParamData]):
+    def remove_params(self, params: List[ParamData]):
         self._writer.remove_params(params)
 
-    def remove_constraints(self, cons: List[_GeneralConstraintData]):
+    def remove_constraints(self, cons: List[ConstraintData]):
         self._writer.remove_constraints(cons)
 
-    def remove_block(self, block: _BlockData):
+    def remove_block(self, block: BlockData):
         self._writer.remove_block(block)
 
-    def set_objective(self, obj: _GeneralObjectiveData):
+    def set_objective(self, obj: ObjectiveData):
         self._writer.set_objective(obj)
 
-    def update_variables(self, variables: List[_GeneralVarData]):
+    def update_variables(self, variables: List[VarData]):
         self._writer.update_variables(variables)
 
     def update_params(self):
@@ -330,9 +341,11 @@ def _postsolve(self, timer: HierarchicalTimer, solve_time):
         if config.load_solution:
             if cpxprob.solution.get_solution_type() == cpxprob.solution.type.none:
                 raise RuntimeError(
-                    'A feasible solution was not found, so no solution can be loades. '
-                    'Please set opt.config.load_solution=False and check '
-                    'results.termination_condition and '
+                    'A feasible solution was not found, so no solution can be loaded. '
+                    'If using the appsi.solvers.Cplex interface, you can '
+                    'set opt.config.load_solution=False. If using the environ.SolverFactory '
+                    'interface, you can set opt.solve(model, load_solutions = False). '
+                    'Then you can check results.termination_condition and '
                     'results.best_feasible_objective before loading a solution.'
                 )
             else:
@@ -349,8 +362,8 @@ def _postsolve(self, timer: HierarchicalTimer, solve_time):
         return results
 
     def get_primals(
-        self, vars_to_load: Optional[Sequence[_GeneralVarData]] = None
-    ) -> Mapping[_GeneralVarData, float]:
+        self, vars_to_load: Optional[Sequence[VarData]] = None
+    ) -> Mapping[VarData, float]:
         if (
             self._cplex_model.solution.get_solution_type()
             == self._cplex_model.solution.type.none
@@ -376,8 +389,8 @@ def get_primals(
         return res
 
     def get_duals(
-        self, cons_to_load: Optional[Sequence[_GeneralConstraintData]] = None
-    ) -> Dict[_GeneralConstraintData, float]:
+        self, cons_to_load: Optional[Sequence[ConstraintData]] = None
+    ) -> Dict[ConstraintData, float]:
         if (
             self._cplex_model.solution.get_solution_type()
             == self._cplex_model.solution.type.none
@@ -427,8 +440,8 @@ def get_duals(
         return res
 
     def get_reduced_costs(
-        self, vars_to_load: Optional[Sequence[_GeneralVarData]] = None
-    ) -> Mapping[_GeneralVarData, float]:
+        self, vars_to_load: Optional[Sequence[VarData]] = None
+    ) -> Mapping[VarData, float]:
         if (
             self._cplex_model.solution.get_solution_type()
             == self._cplex_model.solution.type.none
diff --git a/pyomo/contrib/appsi/solvers/gurobi.py b/pyomo/contrib/appsi/solvers/gurobi.py
index a173c69abc6..2719ecc2a00 100644
--- a/pyomo/contrib/appsi/solvers/gurobi.py
+++ b/pyomo/contrib/appsi/solvers/gurobi.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from collections.abc import Iterable
 import logging
 import math
@@ -12,10 +23,10 @@
 from pyomo.common.config import ConfigValue, NonNegativeInt
 from pyomo.core.kernel.objective import minimize, maximize
 from pyomo.core.base import SymbolMap, NumericLabeler, TextLabeler
-from pyomo.core.base.var import Var, _GeneralVarData
-from pyomo.core.base.constraint import _GeneralConstraintData
-from pyomo.core.base.sos import _SOSConstraintData
-from pyomo.core.base.param import _ParamData
+from pyomo.core.base.var import Var, VarData
+from pyomo.core.base.constraint import ConstraintData
+from pyomo.core.base.sos import SOSConstraintData
+from pyomo.core.base.param import ParamData
 from pyomo.core.expr.numvalue import value, is_constant, is_fixed, native_numeric_types
 from pyomo.repn import generate_standard_repn
 from pyomo.core.expr.numeric_expr import NPV_MaxExpression, NPV_MinExpression
@@ -447,7 +458,7 @@ def _process_domain_and_bounds(
 
         return lb, ub, vtype
 
-    def _add_variables(self, variables: List[_GeneralVarData]):
+    def _add_variables(self, variables: List[VarData]):
         var_names = list()
         vtypes = list()
         lbs = list()
@@ -478,7 +489,7 @@ def _add_variables(self, variables: List[_GeneralVarData]):
         self._vars_added_since_update.update(variables)
         self._needs_updated = True
 
-    def _add_params(self, params: List[_ParamData]):
+    def _add_params(self, params: List[ParamData]):
         pass
 
     def _reinit(self):
@@ -568,7 +579,7 @@ def _get_expr_from_pyomo_expr(self, expr):
             mutable_quadratic_coefficients,
         )
 
-    def _add_constraints(self, cons: List[_GeneralConstraintData]):
+    def _add_constraints(self, cons: List[ConstraintData]):
         for con in cons:
             conname = self._symbol_map.getSymbol(con, self._labeler)
             (
@@ -698,7 +709,7 @@ def _add_constraints(self, cons: List[_GeneralConstraintData]):
         self._constraints_added_since_update.update(cons)
         self._needs_updated = True
 
-    def _add_sos_constraints(self, cons: List[_SOSConstraintData]):
+    def _add_sos_constraints(self, cons: List[SOSConstraintData]):
         for con in cons:
             conname = self._symbol_map.getSymbol(con, self._labeler)
             level = con.level
@@ -724,7 +735,7 @@ def _add_sos_constraints(self, cons: List[_SOSConstraintData]):
         self._constraints_added_since_update.update(cons)
         self._needs_updated = True
 
-    def _remove_constraints(self, cons: List[_GeneralConstraintData]):
+    def _remove_constraints(self, cons: List[ConstraintData]):
         for con in cons:
             if con in self._constraints_added_since_update:
                 self._update_gurobi_model()
@@ -738,7 +749,7 @@ def _remove_constraints(self, cons: List[_GeneralConstraintData]):
             self._mutable_quadratic_helpers.pop(con, None)
         self._needs_updated = True
 
-    def _remove_sos_constraints(self, cons: List[_SOSConstraintData]):
+    def _remove_sos_constraints(self, cons: List[SOSConstraintData]):
         for con in cons:
             if con in self._constraints_added_since_update:
                 self._update_gurobi_model()
@@ -748,7 +759,7 @@ def _remove_sos_constraints(self, cons: List[_SOSConstraintData]):
             del self._pyomo_sos_to_solver_sos_map[con]
         self._needs_updated = True
 
-    def _remove_variables(self, variables: List[_GeneralVarData]):
+    def _remove_variables(self, variables: List[VarData]):
         for var in variables:
             v_id = id(var)
             if var in self._vars_added_since_update:
@@ -760,10 +771,10 @@ def _remove_variables(self, variables: List[_GeneralVarData]):
             self._mutable_bounds.pop(v_id, None)
         self._needs_updated = True
 
-    def _remove_params(self, params: List[_ParamData]):
+    def _remove_params(self, params: List[ParamData]):
         pass
 
-    def _update_variables(self, variables: List[_GeneralVarData]):
+    def _update_variables(self, variables: List[VarData]):
         for var in variables:
             var_id = id(var)
             if var_id not in self._pyomo_var_to_solver_var_map:
@@ -935,9 +946,11 @@ def _postsolve(self, timer: HierarchicalTimer):
                 self.load_vars()
             else:
                 raise RuntimeError(
-                    'A feasible solution was not found, so no solution can be loaded.'
-                    'Please set opt.config.load_solution=False and check '
-                    'results.termination_condition and '
+                    'A feasible solution was not found, so no solution can be loaded. '
+                    'If using the appsi.solvers.Gurobi interface, you can '
+                    'set opt.config.load_solution=False. If using the environ.SolverFactory '
+                    'interface, you can set opt.solve(model, load_solutions = False). '
+                    'Then you can check results.termination_condition and '
                     'results.best_feasible_objective before loading a solution.'
                 )
         timer.stop('load solution')
@@ -1182,7 +1195,7 @@ def set_linear_constraint_attr(self, con, attr, val):
 
         Parameters
         ----------
-        con: pyomo.core.base.constraint._GeneralConstraintData
+        con: pyomo.core.base.constraint.ConstraintData
             The pyomo constraint for which the corresponding gurobi constraint attribute
             should be modified.
         attr: str
@@ -1208,7 +1221,7 @@ def set_var_attr(self, var, attr, val):
 
         Parameters
         ----------
-        var: pyomo.core.base.var._GeneralVarData
+        var: pyomo.core.base.var.VarData
             The pyomo var for which the corresponding gurobi var attribute
             should be modified.
         attr: str
@@ -1243,7 +1256,7 @@ def get_var_attr(self, var, attr):
 
         Parameters
         ----------
-        var: pyomo.core.base.var._GeneralVarData
+        var: pyomo.core.base.var.VarData
             The pyomo var for which the corresponding gurobi var attribute
             should be retrieved.
         attr: str
@@ -1259,7 +1272,7 @@ def get_linear_constraint_attr(self, con, attr):
 
         Parameters
         ----------
-        con: pyomo.core.base.constraint._GeneralConstraintData
+        con: pyomo.core.base.constraint.ConstraintData
             The pyomo constraint for which the corresponding gurobi constraint attribute
             should be retrieved.
         attr: str
@@ -1275,7 +1288,7 @@ def get_sos_attr(self, con, attr):
 
         Parameters
         ----------
-        con: pyomo.core.base.sos._SOSConstraintData
+        con: pyomo.core.base.sos.SOSConstraintData
             The pyomo SOS constraint for which the corresponding gurobi SOS constraint attribute
             should be retrieved.
         attr: str
@@ -1291,7 +1304,7 @@ def get_quadratic_constraint_attr(self, con, attr):
 
         Parameters
         ----------
-        con: pyomo.core.base.constraint._GeneralConstraintData
+        con: pyomo.core.base.constraint.ConstraintData
             The pyomo constraint for which the corresponding gurobi constraint attribute
             should be retrieved.
         attr: str
@@ -1412,7 +1425,7 @@ def cbCut(self, con):
 
         Parameters
         ----------
-        con: pyomo.core.base.constraint._GeneralConstraintData
+        con: pyomo.core.base.constraint.ConstraintData
             The cut to add
         """
         if not con.active:
@@ -1497,7 +1510,7 @@ def cbLazy(self, con):
         """
         Parameters
         ----------
-        con: pyomo.core.base.constraint._GeneralConstraintData
+        con: pyomo.core.base.constraint.ConstraintData
             The lazy constraint to add
         """
         if not con.active:
diff --git a/pyomo/contrib/appsi/solvers/highs.py b/pyomo/contrib/appsi/solvers/highs.py
index 3d498f9388e..57a7b1eac72 100644
--- a/pyomo/contrib/appsi/solvers/highs.py
+++ b/pyomo/contrib/appsi/solvers/highs.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import logging
 from typing import List, Dict, Optional
 from pyomo.common.collections import ComponentMap
@@ -9,10 +20,10 @@
 from pyomo.common.log import LogStream
 from pyomo.core.kernel.objective import minimize, maximize
 from pyomo.core.base import SymbolMap
-from pyomo.core.base.var import _GeneralVarData
-from pyomo.core.base.constraint import _GeneralConstraintData
-from pyomo.core.base.sos import _SOSConstraintData
-from pyomo.core.base.param import _ParamData
+from pyomo.core.base.var import VarData
+from pyomo.core.base.constraint import ConstraintData
+from pyomo.core.base.sos import SOSConstraintData
+from pyomo.core.base.param import ParamData
 from pyomo.core.expr.numvalue import value, is_constant
 from pyomo.repn import generate_standard_repn
 from pyomo.core.expr.numeric_expr import NPV_MaxExpression, NPV_MinExpression
@@ -165,11 +176,19 @@ def available(self):
             return self.Availability.NotFound
 
     def version(self):
-        version = (
-            highspy.HIGHS_VERSION_MAJOR,
-            highspy.HIGHS_VERSION_MINOR,
-            highspy.HIGHS_VERSION_PATCH,
-        )
+        try:
+            version = (
+                highspy.HIGHS_VERSION_MAJOR,
+                highspy.HIGHS_VERSION_MINOR,
+                highspy.HIGHS_VERSION_PATCH,
+            )
+        except AttributeError:
+            # Older versions of Highs do not have the above attributes
+            # and the solver version can only be obtained by making
+            # an instance of the solver class.
+            tmp = highspy.Highs()
+            version = (tmp.versionMajor(), tmp.versionMinor(), tmp.versionPatch())
+
         return version
 
     @property
@@ -297,7 +316,7 @@ def _process_domain_and_bounds(self, var_id):
 
         return lb, ub, vtype
 
-    def _add_variables(self, variables: List[_GeneralVarData]):
+    def _add_variables(self, variables: List[VarData]):
         self._sol = None
         if self._last_results_object is not None:
             self._last_results_object.solution_loader.invalidate()
@@ -324,7 +343,7 @@ def _add_variables(self, variables: List[_GeneralVarData]):
             len(vtypes), np.array(indices), np.array(vtypes)
         )
 
-    def _add_params(self, params: List[_ParamData]):
+    def _add_params(self, params: List[ParamData]):
         pass
 
     def _reinit(self):
@@ -365,7 +384,7 @@ def set_instance(self, model):
                 if self._objective is None:
                     self.set_objective(None)
 
-    def _add_constraints(self, cons: List[_GeneralConstraintData]):
+    def _add_constraints(self, cons: List[ConstraintData]):
         self._sol = None
         if self._last_results_object is not None:
             self._last_results_object.solution_loader.invalidate()
@@ -445,13 +464,13 @@ def _add_constraints(self, cons: List[_GeneralConstraintData]):
             np.array(coef_values, dtype=np.double),
         )
 
-    def _add_sos_constraints(self, cons: List[_SOSConstraintData]):
+    def _add_sos_constraints(self, cons: List[SOSConstraintData]):
         if cons:
             raise NotImplementedError(
                 'Highs interface does not support SOS constraints'
             )
 
-    def _remove_constraints(self, cons: List[_GeneralConstraintData]):
+    def _remove_constraints(self, cons: List[ConstraintData]):
         self._sol = None
         if self._last_results_object is not None:
             self._last_results_object.solution_loader.invalidate()
@@ -462,7 +481,7 @@ def _remove_constraints(self, cons: List[_GeneralConstraintData]):
             indices_to_remove.append(con_ndx)
             self._mutable_helpers.pop(con, None)
         self._solver_model.deleteRows(
-            len(indices_to_remove), np.array(indices_to_remove)
+            len(indices_to_remove), np.sort(np.array(indices_to_remove))
         )
         con_ndx = 0
         new_con_map = dict()
@@ -476,13 +495,13 @@ def _remove_constraints(self, cons: List[_GeneralConstraintData]):
             {v: k for k, v in self._pyomo_con_to_solver_con_map.items()}
         )
 
-    def _remove_sos_constraints(self, cons: List[_SOSConstraintData]):
+    def _remove_sos_constraints(self, cons: List[SOSConstraintData]):
         if cons:
             raise NotImplementedError(
                 'Highs interface does not support SOS constraints'
             )
 
-    def _remove_variables(self, variables: List[_GeneralVarData]):
+    def _remove_variables(self, variables: List[VarData]):
         self._sol = None
         if self._last_results_object is not None:
             self._last_results_object.solution_loader.invalidate()
@@ -504,10 +523,10 @@ def _remove_variables(self, variables: List[_GeneralVarData]):
         self._pyomo_var_to_solver_var_map.clear()
         self._pyomo_var_to_solver_var_map.update(new_var_map)
 
-    def _remove_params(self, params: List[_ParamData]):
+    def _remove_params(self, params: List[ParamData]):
         pass
 
-    def _update_variables(self, variables: List[_GeneralVarData]):
+    def _update_variables(self, variables: List[VarData]):
         self._sol = None
         if self._last_results_object is not None:
             self._last_results_object.solution_loader.invalidate()
@@ -669,9 +688,11 @@ def _postsolve(self, timer: HierarchicalTimer):
                 self.load_vars()
             else:
                 raise RuntimeError(
-                    'A feasible solution was not found, so no solution can be loaded.'
-                    'Please set opt.config.load_solution=False and check '
-                    'results.termination_condition and '
+                    'A feasible solution was not found, so no solution can be loaded. '
+                    'If using the appsi.solvers.Highs interface, you can '
+                    'set opt.config.load_solution=False. If using the environ.SolverFactory '
+                    'interface, you can set opt.solve(model, load_solutions = False). '
+                    'Then you can check results.termination_condition and '
                     'results.best_feasible_objective before loading a solution.'
                 )
         timer.stop('load solution')
diff --git a/pyomo/contrib/appsi/solvers/ipopt.py b/pyomo/contrib/appsi/solvers/ipopt.py
index d38a836a2ac..76cd204e36d 100644
--- a/pyomo/contrib/appsi/solvers/ipopt.py
+++ b/pyomo/contrib/appsi/solvers/ipopt.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.common.tempfiles import TempfileManager
 from pyomo.common.fileutils import Executable
 from pyomo.contrib.appsi.base import (
@@ -17,11 +28,11 @@
 from pyomo.core.expr.numvalue import value
 from pyomo.core.expr.visitor import replace_expressions
 from typing import Optional, Sequence, NoReturn, List, Mapping
-from pyomo.core.base.var import _GeneralVarData
-from pyomo.core.base.constraint import _GeneralConstraintData
-from pyomo.core.base.block import _BlockData
-from pyomo.core.base.param import _ParamData
-from pyomo.core.base.objective import _GeneralObjectiveData
+from pyomo.core.base.var import VarData
+from pyomo.core.base.constraint import ConstraintData
+from pyomo.core.base.block import BlockData
+from pyomo.core.base.param import ParamData
+from pyomo.core.base.objective import ObjectiveData
 from pyomo.common.timing import HierarchicalTimer
 from pyomo.common.tee import TeeStream
 import sys
@@ -136,6 +147,7 @@ def __init__(self, only_child_vars=False):
         self._primal_sol = ComponentMap()
         self._reduced_costs = ComponentMap()
         self._last_results_object: Optional[Results] = None
+        self._version_timeout = 2
 
     def available(self):
         if self.config.executable.path() is None:
@@ -147,7 +159,7 @@ def available(self):
     def version(self):
         results = subprocess.run(
             [str(self.config.executable), '--version'],
-            timeout=1,
+            timeout=self._version_timeout,
             stdout=subprocess.PIPE,
             stderr=subprocess.STDOUT,
             universal_newlines=True,
@@ -216,34 +228,34 @@ def set_instance(self, model):
         self._writer.config.symbolic_solver_labels = self.config.symbolic_solver_labels
         self._writer.set_instance(model)
 
-    def add_variables(self, variables: List[_GeneralVarData]):
+    def add_variables(self, variables: List[VarData]):
         self._writer.add_variables(variables)
 
-    def add_params(self, params: List[_ParamData]):
+    def add_params(self, params: List[ParamData]):
         self._writer.add_params(params)
 
-    def add_constraints(self, cons: List[_GeneralConstraintData]):
+    def add_constraints(self, cons: List[ConstraintData]):
         self._writer.add_constraints(cons)
 
-    def add_block(self, block: _BlockData):
+    def add_block(self, block: BlockData):
         self._writer.add_block(block)
 
-    def remove_variables(self, variables: List[_GeneralVarData]):
+    def remove_variables(self, variables: List[VarData]):
         self._writer.remove_variables(variables)
 
-    def remove_params(self, params: List[_ParamData]):
+    def remove_params(self, params: List[ParamData]):
         self._writer.remove_params(params)
 
-    def remove_constraints(self, cons: List[_GeneralConstraintData]):
+    def remove_constraints(self, cons: List[ConstraintData]):
         self._writer.remove_constraints(cons)
 
-    def remove_block(self, block: _BlockData):
+    def remove_block(self, block: BlockData):
         self._writer.remove_block(block)
 
-    def set_objective(self, obj: _GeneralObjectiveData):
+    def set_objective(self, obj: ObjectiveData):
         self._writer.set_objective(obj)
 
-    def update_variables(self, variables: List[_GeneralVarData]):
+    def update_variables(self, variables: List[VarData]):
         self._writer.update_variables(variables)
 
     def update_params(self):
@@ -410,9 +422,11 @@ def _parse_sol(self):
                 results.best_feasible_objective = value(obj_expr_evaluated)
         elif self.config.load_solution:
             raise RuntimeError(
-                'A feasible solution was not found, so no solution can be loaded.'
-                'Please set opt.config.load_solution=False and check '
-                'results.termination_condition and '
+                'A feasible solution was not found, so no solution can be loaded. '
+                'If using the appsi.solvers.Ipopt interface, you can '
+                'set opt.config.load_solution=False. If using the environ.SolverFactory '
+                'interface, you can set opt.solve(model, load_solutions = False). '
+                'Then you can check results.termination_condition and '
                 'results.best_feasible_objective before loading a solution.'
             )
 
@@ -500,8 +514,8 @@ def _apply_solver(self, timer: HierarchicalTimer):
         return results
 
     def get_primals(
-        self, vars_to_load: Optional[Sequence[_GeneralVarData]] = None
-    ) -> Mapping[_GeneralVarData, float]:
+        self, vars_to_load: Optional[Sequence[VarData]] = None
+    ) -> Mapping[VarData, float]:
         if (
             self._last_results_object is None
             or self._last_results_object.best_feasible_objective is None
@@ -520,9 +534,7 @@ def get_primals(
                 res[v] = self._primal_sol[v]
         return res
 
-    def get_duals(
-        self, cons_to_load: Optional[Sequence[_GeneralConstraintData]] = None
-    ):
+    def get_duals(self, cons_to_load: Optional[Sequence[ConstraintData]] = None):
         if (
             self._last_results_object is None
             or self._last_results_object.termination_condition
@@ -539,8 +551,8 @@ def get_duals(
             return {c: self._dual_sol[c] for c in cons_to_load}
 
     def get_reduced_costs(
-        self, vars_to_load: Optional[Sequence[_GeneralVarData]] = None
-    ) -> Mapping[_GeneralVarData, float]:
+        self, vars_to_load: Optional[Sequence[VarData]] = None
+    ) -> Mapping[VarData, float]:
         if (
             self._last_results_object is None
             or self._last_results_object.termination_condition
diff --git a/pyomo/contrib/appsi/solvers/maingo.py b/pyomo/contrib/appsi/solvers/maingo.py
new file mode 100644
index 00000000000..c5860b42ce7
--- /dev/null
+++ b/pyomo/contrib/appsi/solvers/maingo.py
@@ -0,0 +1,550 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+from collections import namedtuple
+import logging
+import math
+import sys
+from typing import Optional, List, Dict
+
+from pyomo.contrib.appsi.base import (
+    PersistentSolver,
+    Results,
+    TerminationCondition,
+    MIPSolverConfig,
+    PersistentBase,
+    PersistentSolutionLoader,
+)
+from pyomo.contrib.appsi.cmodel import cmodel, cmodel_available
+from pyomo.common.collections import ComponentMap
+from pyomo.common.config import (
+    ConfigValue,
+    ConfigDict,
+    NonNegativeInt,
+    NonNegativeFloat,
+)
+from pyomo.common.dependencies import attempt_import
+from pyomo.common.errors import PyomoException
+from pyomo.common.log import LogStream
+from pyomo.common.tee import capture_output, TeeStream
+from pyomo.common.timing import HierarchicalTimer
+from pyomo.core.base import SymbolMap, NumericLabeler, TextLabeler
+from pyomo.core.base.constraint import _GeneralConstraintData
+from pyomo.core.base.expression import ScalarExpression
+from pyomo.core.base.param import _ParamData
+from pyomo.core.base.sos import _SOSConstraintData
+from pyomo.core.base.var import Var, ScalarVar, _GeneralVarData
+import pyomo.core.expr.expr_common as common
+import pyomo.core.expr as EXPR
+from pyomo.core.expr.numvalue import (
+    value,
+    is_constant,
+    is_fixed,
+    native_numeric_types,
+    native_types,
+    nonpyomo_leaf_types,
+)
+from pyomo.core.kernel.objective import minimize, maximize
+from pyomo.core.staleflag import StaleFlagManager
+from pyomo.repn.util import valid_expr_ctypes_minlp
+
+
+logger = logging.getLogger(__name__)
+MaingoVar = namedtuple("MaingoVar", "type name lb ub init")
+maingopy, maingopy_available = attempt_import("maingopy")
+# Note that importing maingo_solvermodel will trigger the import of
+# maingopy, so we defer that import using attempt_import (which will
+# always succeed, even if maingopy is not available)
+maingo_solvermodel = attempt_import("pyomo.contrib.appsi.solvers.maingo_solvermodel")[0]
+
+
+class MAiNGOConfig(MIPSolverConfig):
+    def __init__(
+        self,
+        description=None,
+        doc=None,
+        implicit=False,
+        implicit_domain=None,
+        visibility=0,
+    ):
+        super(MAiNGOConfig, self).__init__(
+            description=description,
+            doc=doc,
+            implicit=implicit,
+            implicit_domain=implicit_domain,
+            visibility=visibility,
+        )
+        self.tolerances: ConfigDict = self.declare(
+            'tolerances', ConfigDict(implicit=True)
+        )
+
+        self.tolerances.epsilonA: Optional[float] = self.tolerances.declare(
+            'epsilonA',
+            ConfigValue(
+                domain=NonNegativeFloat,
+                default=1e-5,
+                description="Absolute optimality tolerance",
+            ),
+        )
+        self.tolerances.epsilonR: Optional[float] = self.tolerances.declare(
+            'epsilonR',
+            ConfigValue(
+                domain=NonNegativeFloat,
+                default=1e-5,
+                description="Relative optimality tolerance",
+            ),
+        )
+        self.tolerances.deltaEq: Optional[float] = self.tolerances.declare(
+            'deltaEq',
+            ConfigValue(
+                domain=NonNegativeFloat, default=1e-6, description="Equality tolerance"
+            ),
+        )
+
+        self.tolerances.deltaIneq: Optional[float] = self.tolerances.declare(
+            'deltaIneq',
+            ConfigValue(
+                domain=NonNegativeFloat,
+                default=1e-6,
+                description="Inequality tolerance",
+            ),
+        )
+        self.declare("logfile", ConfigValue(domain=str, default=""))
+        self.declare("solver_output_logger", ConfigValue(default=logger))
+        self.declare(
+            "log_level", ConfigValue(domain=NonNegativeInt, default=logging.INFO)
+        )
+
+
+class MAiNGOSolutionLoader(PersistentSolutionLoader):
+    def load_vars(self, vars_to_load=None):
+        self._assert_solution_still_valid()
+        self._solver.load_vars(vars_to_load=vars_to_load)
+
+    def get_primals(self, vars_to_load=None):
+        self._assert_solution_still_valid()
+        return self._solver.get_primals(vars_to_load=vars_to_load)
+
+
+class MAiNGOResults(Results):
+    def __init__(self, solver):
+        super(MAiNGOResults, self).__init__()
+        self.wallclock_time = None
+        self.cpu_time = None
+        self.globally_optimal = None
+        self.solution_loader = MAiNGOSolutionLoader(solver=solver)
+
+
+class MAiNGO(PersistentBase, PersistentSolver):
+    """
+    Interface to MAiNGO
+    """
+
+    _available = None
+
+    def __init__(self, only_child_vars=False):
+        super(MAiNGO, self).__init__(only_child_vars=only_child_vars)
+        self._config = MAiNGOConfig()
+        self._solver_options = dict()
+        self._solver_model = None
+        self._mymaingo = None
+        self._symbol_map = SymbolMap()
+        self._labeler = None
+        self._maingo_vars = []
+        self._objective = None
+        self._cons = []
+        self._pyomo_var_to_solver_var_id_map = dict()
+        self._last_results_object: Optional[MAiNGOResults] = None
+
+    def available(self):
+        if self._available is None:
+            if maingopy_available:
+                MAiNGO._available = True
+            else:
+                MAiNGO._available = MAiNGO.Availability.NotFound
+        return self._available
+
+    def version(self):
+        import pkg_resources
+
+        version = pkg_resources.get_distribution('maingopy').version
+
+        return tuple(int(k) for k in version.split('.'))
+
+    @property
+    def config(self) -> MAiNGOConfig:
+        return self._config
+
+    @config.setter
+    def config(self, val: MAiNGOConfig):
+        self._config = val
+
+    @property
+    def maingo_options(self):
+        """
+        A dictionary mapping solver options to values for those options. These
+        are solver specific.
+
+        Returns
+        -------
+        dict
+            A dictionary mapping solver options to values for those options
+        """
+        return self._solver_options
+
+    @maingo_options.setter
+    def maingo_options(self, val: Dict):
+        self._solver_options = val
+
+    @property
+    def symbol_map(self):
+        return self._symbol_map
+
+    def _solve(self, timer: HierarchicalTimer):
+        ostreams = [
+            LogStream(
+                level=self.config.log_level, logger=self.config.solver_output_logger
+            )
+        ]
+        if self.config.stream_solver:
+            ostreams.append(sys.stdout)
+
+        with TeeStream(*ostreams) as t:
+            with capture_output(output=t.STDOUT, capture_fd=False):
+                config = self.config
+                options = self.maingo_options
+
+                self._mymaingo = maingopy.MAiNGO(self._solver_model)
+
+                self._mymaingo.set_option("loggingDestination", 2)
+                self._mymaingo.set_log_file_name(config.logfile)
+                self._mymaingo.set_option("epsilonA", config.tolerances.epsilonA)
+                self._mymaingo.set_option("epsilonR", config.tolerances.epsilonR)
+                self._mymaingo.set_option("deltaEq", config.tolerances.deltaEq)
+                self._mymaingo.set_option("deltaIneq", config.tolerances.deltaIneq)
+
+                if config.time_limit is not None:
+                    self._mymaingo.set_option("maxTime", config.time_limit)
+                if config.mip_gap is not None:
+                    self._mymaingo.set_option("epsilonR", config.mip_gap)
+                for key, option in options.items():
+                    self._mymaingo.set_option(key, option)
+
+                timer.start("MAiNGO solve")
+                self._mymaingo.solve()
+                timer.stop("MAiNGO solve")
+
+        return self._postsolve(timer)
+
+    def solve(self, model, timer: HierarchicalTimer = None):
+        StaleFlagManager.mark_all_as_stale()
+
+        if self._last_results_object is not None:
+            self._last_results_object.solution_loader.invalidate()
+        if timer is None:
+            timer = HierarchicalTimer()
+        if model is not self._model:
+            timer.start("set_instance")
+            self.set_instance(model)
+            timer.stop("set_instance")
+        else:
+            timer.start("Update")
+            self.update(timer=timer)
+            timer.stop("Update")
+        res = self._solve(timer)
+        self._last_results_object = res
+        if self.config.report_timing:
+            logger.info("\n" + str(timer))
+        return res
+
+    def _process_domain_and_bounds(self, var):
+        _v, _lb, _ub, _fixed, _domain_interval, _value = self._vars[id(var)]
+        lb, ub, step = _domain_interval
+
+        if _fixed:
+            lb = _value
+            ub = _value
+        else:
+            if lb is None and _lb is None:
+                logger.warning(
+                    "No lower bound for variable "
+                    + var.getname()
+                    + " set. Using -1e10 instead. Please consider setting a valid lower bound."
+                )
+            if ub is None and _ub is None:
+                logger.warning(
+                    "No upper bound for variable "
+                    + var.getname()
+                    + " set. Using +1e10 instead. Please consider setting a valid upper bound."
+                )
+
+            if _lb is None:
+                _lb = -1e10
+            if _ub is None:
+                _ub = 1e10
+            if lb is None:
+                lb = -1e10
+            if ub is None:
+                ub = 1e10
+
+            lb = max(value(_lb), lb)
+            ub = min(value(_ub), ub)
+
+        if step == 0:
+            vtype = maingopy.VT_CONTINUOUS
+        elif step == 1:
+            if lb == 0 and ub == 1:
+                vtype = maingopy.VT_BINARY
+            else:
+                vtype = maingopy.VT_INTEGER
+        else:
+            raise ValueError(
+                f"Unrecognized domain step: {step} (should be either 0 or 1)"
+            )
+
+        return lb, ub, vtype
+
+    def _add_variables(self, variables: List[_GeneralVarData]):
+        for var in variables:
+            varname = self._symbol_map.getSymbol(var, self._labeler)
+            lb, ub, vtype = self._process_domain_and_bounds(var)
+            self._maingo_vars.append(
+                MaingoVar(name=varname, type=vtype, lb=lb, ub=ub, init=var.value)
+            )
+            self._pyomo_var_to_solver_var_id_map[id(var)] = len(self._maingo_vars) - 1
+
+    def _add_params(self, params: List[_ParamData]):
+        pass
+
+    def _reinit(self):
+        saved_config = self.config
+        saved_options = self.maingo_options
+        saved_update_config = self.update_config
+        self.__init__(only_child_vars=self._only_child_vars)
+        self.config = saved_config
+        self.maingo_options = saved_options
+        self.update_config = saved_update_config
+
+    def set_instance(self, model):
+        if self._last_results_object is not None:
+            self._last_results_object.solution_loader.invalidate()
+        if not self.available():
+            c = self.__class__
+            raise PyomoException(
+                f"Solver {c.__module__}.{c.__qualname__} is not available "
+                f"({self.available()})."
+            )
+        self._reinit()
+        self._model = model
+        if self.use_extensions and cmodel_available:
+            self._expr_types = cmodel.PyomoExprTypes()
+
+        if self.config.symbolic_solver_labels:
+            self._labeler = TextLabeler()
+        else:
+            self._labeler = NumericLabeler("x")
+
+        self.add_block(model)
+
+        self._solver_model = maingo_solvermodel.SolverModel(
+            var_list=self._maingo_vars,
+            con_list=self._cons,
+            objective=self._objective,
+            idmap=self._pyomo_var_to_solver_var_id_map,
+            logger=logger,
+        )
+
+    def _add_constraints(self, cons: List[_GeneralConstraintData]):
+        self._cons += cons
+
+    def _add_sos_constraints(self, cons: List[_SOSConstraintData]):
+        if len(cons) >= 1:
+            raise NotImplementedError(
+                "MAiNGO does not currently support SOS constraints."
+            )
+        pass
+
+    def _remove_constraints(self, cons: List[_GeneralConstraintData]):
+        for con in cons:
+            self._cons.remove(con)
+
+    def _remove_sos_constraints(self, cons: List[_SOSConstraintData]):
+        if len(cons) >= 1:
+            raise NotImplementedError(
+                "MAiNGO does not currently support SOS constraints."
+            )
+        pass
+
+    def _remove_variables(self, variables: List[_GeneralVarData]):
+        removed_maingo_vars = []
+        for var in variables:
+            varname = self._symbol_map.getSymbol(var, self._labeler)
+            del self._maingo_vars[self._pyomo_var_to_solver_var_id_map[id(var)]]
+            removed_maingo_vars += [self._pyomo_var_to_solver_var_id_map[id(var)]]
+            del self._pyomo_var_to_solver_var_id_map[id(var)]
+
+        # Update _pyomo_var_to_solver_var_id_map to account for removed variables
+        for pyomo_var, maingo_var_id in self._pyomo_var_to_solver_var_id_map.items():
+            num_removed = 0
+            for removed_var in removed_maingo_vars:
+                if removed_var <= maingo_var_id:
+                    num_removed += 1
+            self._pyomo_var_to_solver_var_id_map[pyomo_var] = (
+                maingo_var_id - num_removed
+            )
+
+    def _remove_params(self, params: List[_ParamData]):
+        pass
+
+    def _update_variables(self, variables: List[_GeneralVarData]):
+        for var in variables:
+            if id(var) not in self._pyomo_var_to_solver_var_id_map:
+                raise ValueError(
+                    'The Var provided to update_var needs to be added first: {0}'.format(
+                        var
+                    )
+                )
+            lb, ub, vtype = self._process_domain_and_bounds(var)
+            self._maingo_vars[self._pyomo_var_to_solver_var_id_map[id(var)]] = (
+                MaingoVar(name=var.name, type=vtype, lb=lb, ub=ub, init=var.value)
+            )
+
+    def update_params(self):
+        vars = [var[0] for var in self._vars.values()]
+        self._update_variables(vars)
+
+    def _set_objective(self, obj):
+
+        if not obj.sense in {minimize, maximize}:
+            raise ValueError("Objective sense is not recognized: {0}".format(obj.sense))
+        self._objective = obj
+
+    def _postsolve(self, timer: HierarchicalTimer):
+        config = self.config
+
+        mprob = self._mymaingo
+        status = mprob.get_status()
+        results = MAiNGOResults(solver=self)
+        results.wallclock_time = mprob.get_wallclock_solution_time()
+        results.cpu_time = mprob.get_cpu_solution_time()
+
+        if status in {maingopy.GLOBALLY_OPTIMAL, maingopy.FEASIBLE_POINT}:
+            results.termination_condition = TerminationCondition.optimal
+            results.globally_optimal = True
+            if status == maingopy.FEASIBLE_POINT:
+                results.globally_optimal = False
+                logger.warning(
+                    "MAiNGO found a feasible solution but did not prove its global optimality."
+                )
+        elif status == maingopy.INFEASIBLE:
+            results.termination_condition = TerminationCondition.infeasible
+        else:
+            results.termination_condition = TerminationCondition.unknown
+
+        results.best_feasible_objective = None
+        results.best_objective_bound = None
+        if self._objective is not None:
+            try:
+                if self._objective.sense == maximize:
+                    results.best_feasible_objective = -mprob.get_objective_value()
+                else:
+                    results.best_feasible_objective = mprob.get_objective_value()
+            except:
+                results.best_feasible_objective = None
+            try:
+                if self._objective.sense == maximize:
+                    results.best_objective_bound = -mprob.get_final_LBD()
+                else:
+                    results.best_objective_bound = mprob.get_final_LBD()
+            except:
+                if self._objective.sense == maximize:
+                    results.best_objective_bound = math.inf
+                else:
+                    results.best_objective_bound = -math.inf
+
+            if results.best_feasible_objective is not None and not math.isfinite(
+                results.best_feasible_objective
+            ):
+                results.best_feasible_objective = None
+
+        timer.start("load solution")
+        if config.load_solution:
+            if results.termination_condition is TerminationCondition.optimal:
+                if not results.globally_optimal:
+                    logger.warning(
+                        "Loading a feasible but suboptimal solution. "
+                        "Please set load_solution=False and check "
+                        "results.termination_condition and "
+                        "results.found_feasible_solution() before loading a solution."
+                    )
+                self.load_vars()
+            else:
+                raise RuntimeError(
+                    "A feasible solution was not found, so no solution can be loaded."
+                    "Please set opt.config.load_solution=False and check "
+                    "results.termination_condition and "
+                    "results.best_feasible_objective before loading a solution."
+                )
+        timer.stop("load solution")
+
+        return results
+
+    def load_vars(self, vars_to_load=None):
+        for v, val in self.get_primals(vars_to_load=vars_to_load).items():
+            v.set_value(val, skip_validation=True)
+        StaleFlagManager.mark_all_as_stale(delayed=True)
+
+    def get_primals(self, vars_to_load=None):
+        if not self._mymaingo.get_status() in {
+            maingopy.GLOBALLY_OPTIMAL,
+            maingopy.FEASIBLE_POINT,
+        }:
+            raise RuntimeError(
+                "Solver does not currently have a valid solution."
+                "Please check the termination condition."
+            )
+
+        var_id_map = self._pyomo_var_to_solver_var_id_map
+        ref_vars = self._referenced_variables
+        if vars_to_load is None:
+            vars_to_load = var_id_map.keys()
+        else:
+            vars_to_load = [id(v) for v in vars_to_load]
+
+        maingo_var_ids_to_load = [
+            var_id_map[pyomo_var_id] for pyomo_var_id in vars_to_load
+        ]
+
+        solution_point = self._mymaingo.get_solution_point()
+        vals = [solution_point[var_id] for var_id in maingo_var_ids_to_load]
+
+        res = ComponentMap()
+        for var_id, val in zip(vars_to_load, vals):
+            using_cons, using_sos, using_obj = ref_vars[var_id]
+            if using_cons or using_sos or (using_obj is not None):
+                res[self._vars[var_id][0]] = val
+        return res
+
+    def get_reduced_costs(self, vars_to_load=None):
+        raise ValueError("MAiNGO does not support returning Reduced Costs")
+
+    def get_duals(self, cons_to_load=None):
+        raise ValueError("MAiNGO does not support returning Duals")
+
+    def update(self, timer: HierarchicalTimer = None):
+        super(MAiNGO, self).update(timer=timer)
+        self._solver_model = maingo_solvermodel.SolverModel(
+            var_list=self._maingo_vars,
+            con_list=self._cons,
+            objective=self._objective,
+            idmap=self._pyomo_var_to_solver_var_id_map,
+            logger=logger,
+        )
diff --git a/pyomo/contrib/appsi/solvers/maingo_solvermodel.py b/pyomo/contrib/appsi/solvers/maingo_solvermodel.py
new file mode 100644
index 00000000000..b12a386284c
--- /dev/null
+++ b/pyomo/contrib/appsi/solvers/maingo_solvermodel.py
@@ -0,0 +1,283 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import math
+
+from pyomo.common.dependencies import attempt_import
+from pyomo.core.base.var import ScalarVar
+from pyomo.core.base.expression import ScalarExpression
+import pyomo.core.expr.expr_common as common
+import pyomo.core.expr as EXPR
+from pyomo.core.expr.numvalue import (
+    value,
+    is_constant,
+    is_fixed,
+    native_numeric_types,
+    native_types,
+    nonpyomo_leaf_types,
+)
+from pyomo.core.kernel.objective import minimize, maximize
+from pyomo.repn.util import valid_expr_ctypes_minlp
+
+
+maingopy, maingopy_available = attempt_import("maingopy")
+
+_plusMinusOne = {1, -1}
+
+LEFT_TO_RIGHT = common.OperatorAssociativity.LEFT_TO_RIGHT
+RIGHT_TO_LEFT = common.OperatorAssociativity.RIGHT_TO_LEFT
+
+
+class ToMAiNGOVisitor(EXPR.ExpressionValueVisitor):
+    def __init__(self, variables, idmap):
+        super(ToMAiNGOVisitor, self).__init__()
+        self.variables = variables
+        self.idmap = idmap
+        self._pyomo_func_to_maingo_func = {
+            "log": maingopy.log,
+            "log10": ToMAiNGOVisitor.maingo_log10,
+            "sin": maingopy.sin,
+            "cos": maingopy.cos,
+            "tan": maingopy.tan,
+            "cosh": maingopy.cosh,
+            "sinh": maingopy.sinh,
+            "tanh": maingopy.tanh,
+            "asin": maingopy.asin,
+            "acos": maingopy.acos,
+            "atan": maingopy.atan,
+            "exp": maingopy.exp,
+            "sqrt": maingopy.sqrt,
+            "asinh": ToMAiNGOVisitor.maingo_asinh,
+            "acosh": ToMAiNGOVisitor.maingo_acosh,
+            "atanh": ToMAiNGOVisitor.maingo_atanh,
+        }
+
+    @classmethod
+    def maingo_log10(cls, x):
+        return maingopy.log(x) / math.log(10)
+
+    @classmethod
+    def maingo_asinh(cls, x):
+        return maingopy.log(x + maingopy.sqrt(maingopy.pow(x, 2) + 1))
+
+    @classmethod
+    def maingo_acosh(cls, x):
+        return maingopy.log(x + maingopy.sqrt(maingopy.pow(x, 2) - 1))
+
+    @classmethod
+    def maingo_atanh(cls, x):
+        return 0.5 * maingopy.log(x + 1) - 0.5 * maingopy.log(1 - x)
+
+    def visit(self, node, values):
+        """Visit nodes that have been expanded"""
+        for i, val in enumerate(values):
+            arg = node._args_[i]
+
+            if arg is None:
+                values[i] = "Undefined"
+            elif arg.__class__ in native_numeric_types:
+                pass
+            elif arg.__class__ in nonpyomo_leaf_types:
+                values[i] = val
+            else:
+                parens = False
+                if arg.is_expression_type() and node.PRECEDENCE is not None:
+                    if arg.PRECEDENCE is None:
+                        pass
+                    elif node.PRECEDENCE < arg.PRECEDENCE:
+                        parens = True
+                    elif node.PRECEDENCE == arg.PRECEDENCE:
+                        if i == 0:
+                            parens = node.ASSOCIATIVITY != LEFT_TO_RIGHT
+                        elif i == len(node._args_) - 1:
+                            parens = node.ASSOCIATIVITY != RIGHT_TO_LEFT
+                        else:
+                            parens = True
+                if parens:
+                    values[i] = val
+
+        if node.__class__ in EXPR.NPV_expression_types:
+            return value(node)
+
+        if node.__class__ in {EXPR.ProductExpression, EXPR.MonomialTermExpression}:
+            return values[0] * values[1]
+
+        if node.__class__ in {EXPR.SumExpression}:
+            return sum(values)
+
+        if node.__class__ in {EXPR.PowExpression}:
+            return maingopy.pow(values[0], values[1])
+
+        if node.__class__ in {EXPR.DivisionExpression}:
+            return values[0] / values[1]
+
+        if node.__class__ in {EXPR.NegationExpression}:
+            return -values[0]
+
+        if node.__class__ in {EXPR.AbsExpression}:
+            return maingopy.abs(values[0])
+
+        if node.__class__ in {EXPR.UnaryFunctionExpression}:
+            pyomo_func = node.getname()
+            maingo_func = self._pyomo_func_to_maingo_func[pyomo_func]
+            return maingo_func(values[0])
+
+        if node.__class__ in {ScalarExpression}:
+            return values[0]
+
+        raise ValueError(f"Unknown function expression encountered: {node.getname()}")
+
+    def visiting_potential_leaf(self, node):
+        """
+        Visiting a potential leaf.
+
+        Return True if the node is not expanded.
+        """
+        if node.__class__ in native_types:
+            return True, node
+
+        if node.is_expression_type():
+            if node.__class__ is EXPR.MonomialTermExpression:
+                return True, self._monomial_to_maingo(node)
+            if node.__class__ is EXPR.LinearExpression:
+                return True, self._linear_to_maingo(node)
+            return False, None
+
+        if node.is_component_type():
+            if node.ctype not in valid_expr_ctypes_minlp:
+                # Make sure all components in active constraints
+                # are basic ctypes we know how to deal with.
+                raise RuntimeError(
+                    "Unallowable component '%s' of type %s found in an active "
+                    "constraint or objective.\nMAiNGO cannot export "
+                    "expressions with this component type."
+                    % (node.name, node.ctype.__name__)
+                )
+
+        if node.is_fixed():
+            return True, node()
+        else:
+            assert node.is_variable_type()
+            maingo_var_id = self.idmap[id(node)]
+            maingo_var = self.variables[maingo_var_id]
+            return True, maingo_var
+
+    def _monomial_to_maingo(self, node):
+        const, var = node.args
+        if const.__class__ not in native_types:
+            const = value(const)
+        if var.is_fixed():
+            return const * var.value
+        if not const:
+            return 0
+        maingo_var = self._var_to_maingo(var)
+        if const in _plusMinusOne:
+            if const < 0:
+                return -maingo_var
+            else:
+                return maingo_var
+        return const * maingo_var
+
+    def _var_to_maingo(self, var):
+        maingo_var_id = self.idmap[id(var)]
+        maingo_var = self.variables[maingo_var_id]
+        return maingo_var
+
+    def _linear_to_maingo(self, node):
+        values = [
+            (
+                self._monomial_to_maingo(arg)
+                if (arg.__class__ is EXPR.MonomialTermExpression)
+                else (
+                    value(arg)
+                    if arg.__class__ in native_numeric_types
+                    else (
+                        self._var_to_maingo(arg)
+                        if arg.is_variable_type()
+                        else value(arg)
+                    )
+                )
+            )
+            for arg in node.args
+        ]
+        return sum(values)
+
+
+class SolverModel(maingopy.MAiNGOmodel if maingopy_available else object):
+    def __init__(self, var_list, objective, con_list, idmap, logger):
+        maingopy.MAiNGOmodel.__init__(self)
+        self._var_list = var_list
+        self._con_list = con_list
+        self._objective = objective
+        self._idmap = idmap
+        self._logger = logger
+        self._no_objective = False
+
+        if self._objective is None:
+            self._logger.warning("No objective given, setting a dummy objective of 1.")
+            self._no_objective = True
+
+    def build_maingo_objective(self, obj, visitor):
+        if self._no_objective:
+            return visitor.variables[-1]
+        maingo_obj = visitor.dfs_postorder_stack(obj.expr)
+        if obj.sense == maximize:
+            return -1 * maingo_obj
+        return maingo_obj
+
+    def build_maingo_constraints(self, cons, visitor):
+        eqs = []
+        ineqs = []
+        for con in cons:
+            if con.equality:
+                eqs += [visitor.dfs_postorder_stack(con.body - con.lower)]
+            elif con.has_ub() and con.has_lb():
+                ineqs += [visitor.dfs_postorder_stack(con.body - con.upper)]
+                ineqs += [visitor.dfs_postorder_stack(con.lower - con.body)]
+            elif con.has_ub():
+                ineqs += [visitor.dfs_postorder_stack(con.body - con.upper)]
+            elif con.has_lb():
+                ineqs += [visitor.dfs_postorder_stack(con.lower - con.body)]
+            else:
+                raise ValueError(
+                    "Constraint does not have a lower "
+                    "or an upper bound: {0} \n".format(con)
+                )
+        return eqs, ineqs
+
+    def get_variables(self):
+        vars = [
+            maingopy.OptimizationVariable(
+                maingopy.Bounds(var.lb, var.ub), var.type, var.name
+            )
+            for var in self._var_list
+        ]
+        if self._no_objective:
+            vars += [maingopy.OptimizationVariable(maingopy.Bounds(1, 1), "dummy_obj")]
+        return vars
+
+    def get_initial_point(self):
+        initial = [
+            var.init if not var.init is None else (var.lb + var.ub) / 2.0
+            for var in self._var_list
+        ]
+        if self._no_objective:
+            initial += [1]
+        return initial
+
+    def evaluate(self, maingo_vars):
+        visitor = ToMAiNGOVisitor(maingo_vars, self._idmap)
+        result = maingopy.EvaluationContainer()
+        result.objective = self.build_maingo_objective(self._objective, visitor)
+        eqs, ineqs = self.build_maingo_constraints(self._con_list, visitor)
+        result.eq = eqs
+        result.ineq = ineqs
+        return result
diff --git a/pyomo/contrib/appsi/solvers/tests/__init__.py b/pyomo/contrib/appsi/solvers/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/appsi/solvers/tests/__init__.py
+++ b/pyomo/contrib/appsi/solvers/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/appsi/solvers/tests/test_gurobi_persistent.py b/pyomo/contrib/appsi/solvers/tests/test_gurobi_persistent.py
index b032f5c827e..2f674a2eb6a 100644
--- a/pyomo/contrib/appsi/solvers/tests/test_gurobi_persistent.py
+++ b/pyomo/contrib/appsi/solvers/tests/test_gurobi_persistent.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.common.errors import PyomoException
 import pyomo.common.unittest as unittest
 import pyomo.environ as pe
diff --git a/pyomo/contrib/appsi/solvers/tests/test_highs_persistent.py b/pyomo/contrib/appsi/solvers/tests/test_highs_persistent.py
index 6451db18087..4d8251e0de9 100644
--- a/pyomo/contrib/appsi/solvers/tests/test_highs_persistent.py
+++ b/pyomo/contrib/appsi/solvers/tests/test_highs_persistent.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import subprocess
 import sys
 
@@ -69,6 +80,43 @@ def test_mutable_params_with_remove_vars(self):
         res = opt.solve(m)
         self.assertAlmostEqual(res.best_feasible_objective, -9)
 
+    def test_fix_and_unfix(self):
+        # Tests issue https://github.com/Pyomo/pyomo/issues/3127
+
+        m = pe.ConcreteModel()
+        m.x = pe.Var(domain=pe.Binary)
+        m.y = pe.Var(domain=pe.Binary)
+        m.fx = pe.Var(domain=pe.NonNegativeReals)
+        m.fy = pe.Var(domain=pe.NonNegativeReals)
+        m.c1 = pe.Constraint(expr=m.fx <= m.x)
+        m.c2 = pe.Constraint(expr=m.fy <= m.y)
+        m.c3 = pe.Constraint(expr=m.x + m.y <= 1)
+
+        m.obj = pe.Objective(expr=m.fx * 0.5 + m.fy * 0.4, sense=pe.maximize)
+
+        opt = Highs()
+
+        # solution 1 has m.x == 1 and m.y == 0
+        r = opt.solve(m)
+        self.assertAlmostEqual(m.fx.value, 1, places=5)
+        self.assertAlmostEqual(m.fy.value, 0, places=5)
+        self.assertAlmostEqual(r.best_feasible_objective, 0.5, places=5)
+
+        # solution 2 has m.x == 0 and m.y == 1
+        m.y.fix(1)
+        r = opt.solve(m)
+        self.assertAlmostEqual(m.fx.value, 0, places=5)
+        self.assertAlmostEqual(m.fy.value, 1, places=5)
+        self.assertAlmostEqual(r.best_feasible_objective, 0.4, places=5)
+
+        # solution 3 should be equal solution 1
+        m.y.unfix()
+        m.x.fix(1)
+        r = opt.solve(m)
+        self.assertAlmostEqual(m.fx.value, 1, places=5)
+        self.assertAlmostEqual(m.fy.value, 0, places=5)
+        self.assertAlmostEqual(r.best_feasible_objective, 0.5, places=5)
+
     def test_capture_highs_output(self):
         # tests issue #3003
         #
diff --git a/pyomo/contrib/appsi/solvers/tests/test_ipopt_persistent.py b/pyomo/contrib/appsi/solvers/tests/test_ipopt_persistent.py
index 6b86deaa535..8e6473a6b01 100644
--- a/pyomo/contrib/appsi/solvers/tests/test_ipopt_persistent.py
+++ b/pyomo/contrib/appsi/solvers/tests/test_ipopt_persistent.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pe
 import pyomo.common.unittest as unittest
 from pyomo.contrib.appsi.cmodel import cmodel_available
diff --git a/pyomo/contrib/appsi/solvers/tests/test_persistent_solvers.py b/pyomo/contrib/appsi/solvers/tests/test_persistent_solvers.py
index 33f6877aaf8..67088297cf4 100644
--- a/pyomo/contrib/appsi/solvers/tests/test_persistent_solvers.py
+++ b/pyomo/contrib/appsi/solvers/tests/test_persistent_solvers.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pe
 from pyomo.common.dependencies import attempt_import
 import pyomo.common.unittest as unittest
@@ -6,7 +17,7 @@
 parameterized = parameterized.parameterized
 from pyomo.contrib.appsi.base import TerminationCondition, Results, PersistentSolver
 from pyomo.contrib.appsi.cmodel import cmodel_available
-from pyomo.contrib.appsi.solvers import Gurobi, Ipopt, Cplex, Cbc, Highs
+from pyomo.contrib.appsi.solvers import Gurobi, Ipopt, Cplex, Cbc, Highs, MAiNGO
 from typing import Type
 from pyomo.core.expr.numeric_expr import LinearExpression
 import os
@@ -25,11 +36,23 @@
     ('cplex', Cplex),
     ('cbc', Cbc),
     ('highs', Highs),
+    ('maingo', MAiNGO),
+]
+mip_solvers = [
+    ('gurobi', Gurobi),
+    ('cplex', Cplex),
+    ('cbc', Cbc),
+    ('highs', Highs),
+    ('maingo', MAiNGO),
+]
+nlp_solvers = [('ipopt', Ipopt), ('maingo', MAiNGO)]
+qcp_solvers = [
+    ('gurobi', Gurobi),
+    ('ipopt', Ipopt),
+    ('cplex', Cplex),
+    ('maingo', MAiNGO),
 ]
-mip_solvers = [('gurobi', Gurobi), ('cplex', Cplex), ('cbc', Cbc), ('highs', Highs)]
-nlp_solvers = [('ipopt', Ipopt)]
-qcp_solvers = [('gurobi', Gurobi), ('ipopt', Ipopt), ('cplex', Cplex)]
-miqcqp_solvers = [('gurobi', Gurobi), ('cplex', Cplex)]
+miqcqp_solvers = [('gurobi', Gurobi), ('cplex', Cplex), ('maingo', MAiNGO)]
 only_child_vars_options = [True, False]
 
 
@@ -161,14 +184,16 @@ def test_range_constraint(
         res = opt.solve(m)
         self.assertEqual(res.termination_condition, TerminationCondition.optimal)
         self.assertAlmostEqual(m.x.value, -1)
-        duals = opt.get_duals()
-        self.assertAlmostEqual(duals[m.c], 1)
+        if opt_class != MAiNGO:
+            duals = opt.get_duals()
+            self.assertAlmostEqual(duals[m.c], 1)
         m.obj.sense = pe.maximize
         res = opt.solve(m)
         self.assertEqual(res.termination_condition, TerminationCondition.optimal)
         self.assertAlmostEqual(m.x.value, 1)
-        duals = opt.get_duals()
-        self.assertAlmostEqual(duals[m.c], 1)
+        if opt_class != MAiNGO:
+            duals = opt.get_duals()
+            self.assertAlmostEqual(duals[m.c], 1)
 
     @parameterized.expand(input=_load_tests(all_solvers, only_child_vars_options))
     def test_reduced_costs(
@@ -185,9 +210,10 @@ def test_reduced_costs(
         self.assertEqual(res.termination_condition, TerminationCondition.optimal)
         self.assertAlmostEqual(m.x.value, -1)
         self.assertAlmostEqual(m.y.value, -2)
-        rc = opt.get_reduced_costs()
-        self.assertAlmostEqual(rc[m.x], 3)
-        self.assertAlmostEqual(rc[m.y], 4)
+        if opt_class != MAiNGO:
+            rc = opt.get_reduced_costs()
+            self.assertAlmostEqual(rc[m.x], 3)
+            self.assertAlmostEqual(rc[m.y], 4)
 
     @parameterized.expand(input=_load_tests(all_solvers, only_child_vars_options))
     def test_reduced_costs2(
@@ -202,14 +228,16 @@ def test_reduced_costs2(
         res = opt.solve(m)
         self.assertEqual(res.termination_condition, TerminationCondition.optimal)
         self.assertAlmostEqual(m.x.value, -1)
-        rc = opt.get_reduced_costs()
-        self.assertAlmostEqual(rc[m.x], 1)
+        if opt_class != MAiNGO:
+            rc = opt.get_reduced_costs()
+            self.assertAlmostEqual(rc[m.x], 1)
         m.obj.sense = pe.maximize
         res = opt.solve(m)
         self.assertEqual(res.termination_condition, TerminationCondition.optimal)
         self.assertAlmostEqual(m.x.value, 1)
-        rc = opt.get_reduced_costs()
-        self.assertAlmostEqual(rc[m.x], 1)
+        if opt_class != MAiNGO:
+            rc = opt.get_reduced_costs()
+            self.assertAlmostEqual(rc[m.x], 1)
 
     @parameterized.expand(input=_load_tests(all_solvers, only_child_vars_options))
     def test_param_changes(
@@ -241,9 +269,10 @@ def test_param_changes(
             self.assertAlmostEqual(m.y.value, a1 * (b2 - b1) / (a1 - a2) + b1)
             self.assertAlmostEqual(res.best_feasible_objective, m.y.value)
             self.assertTrue(res.best_objective_bound <= m.y.value)
-            duals = opt.get_duals()
-            self.assertAlmostEqual(duals[m.c1], (1 + a1 / (a2 - a1)))
-            self.assertAlmostEqual(duals[m.c2], a1 / (a2 - a1))
+            if opt_class != MAiNGO:
+                duals = opt.get_duals()
+                self.assertAlmostEqual(duals[m.c1], (1 + a1 / (a2 - a1)))
+                self.assertAlmostEqual(duals[m.c2], a1 / (a2 - a1))
 
     @parameterized.expand(input=_load_tests(all_solvers, only_child_vars_options))
     def test_immutable_param(
@@ -279,9 +308,10 @@ def test_immutable_param(
             self.assertAlmostEqual(m.y.value, a1 * (b2 - b1) / (a1 - a2) + b1)
             self.assertAlmostEqual(res.best_feasible_objective, m.y.value)
             self.assertTrue(res.best_objective_bound <= m.y.value)
-            duals = opt.get_duals()
-            self.assertAlmostEqual(duals[m.c1], (1 + a1 / (a2 - a1)))
-            self.assertAlmostEqual(duals[m.c2], a1 / (a2 - a1))
+            if opt_class != MAiNGO:
+                duals = opt.get_duals()
+                self.assertAlmostEqual(duals[m.c1], (1 + a1 / (a2 - a1)))
+                self.assertAlmostEqual(duals[m.c2], a1 / (a2 - a1))
 
     @parameterized.expand(input=_load_tests(all_solvers, only_child_vars_options))
     def test_equality(
@@ -313,9 +343,10 @@ def test_equality(
             self.assertAlmostEqual(m.y.value, a1 * (b2 - b1) / (a1 - a2) + b1)
             self.assertAlmostEqual(res.best_feasible_objective, m.y.value)
             self.assertTrue(res.best_objective_bound <= m.y.value)
-            duals = opt.get_duals()
-            self.assertAlmostEqual(duals[m.c1], (1 + a1 / (a2 - a1)))
-            self.assertAlmostEqual(duals[m.c2], -a1 / (a2 - a1))
+            if opt_class != MAiNGO:
+                duals = opt.get_duals()
+                self.assertAlmostEqual(duals[m.c1], (1 + a1 / (a2 - a1)))
+                self.assertAlmostEqual(duals[m.c2], -a1 / (a2 - a1))
 
     @parameterized.expand(input=_load_tests(all_solvers, only_child_vars_options))
     def test_linear_expression(
@@ -383,9 +414,10 @@ def test_no_objective(
             self.assertAlmostEqual(m.y.value, a1 * (b2 - b1) / (a1 - a2) + b1)
             self.assertEqual(res.best_feasible_objective, None)
             self.assertEqual(res.best_objective_bound, None)
-            duals = opt.get_duals()
-            self.assertAlmostEqual(duals[m.c1], 0)
-            self.assertAlmostEqual(duals[m.c2], 0)
+            if opt_class != MAiNGO:
+                duals = opt.get_duals()
+                self.assertAlmostEqual(duals[m.c1], 0)
+                self.assertAlmostEqual(duals[m.c2], 0)
 
     @parameterized.expand(input=_load_tests(all_solvers, only_child_vars_options))
     def test_add_remove_cons(
@@ -412,9 +444,10 @@ def test_add_remove_cons(
         self.assertAlmostEqual(m.y.value, a1 * (b2 - b1) / (a1 - a2) + b1)
         self.assertAlmostEqual(res.best_feasible_objective, m.y.value)
         self.assertTrue(res.best_objective_bound <= m.y.value)
-        duals = opt.get_duals()
-        self.assertAlmostEqual(duals[m.c1], -(1 + a1 / (a2 - a1)))
-        self.assertAlmostEqual(duals[m.c2], a1 / (a2 - a1))
+        if opt_class != MAiNGO:
+            duals = opt.get_duals()
+            self.assertAlmostEqual(duals[m.c1], -(1 + a1 / (a2 - a1)))
+            self.assertAlmostEqual(duals[m.c2], a1 / (a2 - a1))
 
         m.c3 = pe.Constraint(expr=m.y >= a3 * m.x + b3)
         res = opt.solve(m)
@@ -423,10 +456,11 @@ def test_add_remove_cons(
         self.assertAlmostEqual(m.y.value, a1 * (b3 - b1) / (a1 - a3) + b1)
         self.assertAlmostEqual(res.best_feasible_objective, m.y.value)
         self.assertTrue(res.best_objective_bound <= m.y.value)
-        duals = opt.get_duals()
-        self.assertAlmostEqual(duals[m.c1], -(1 + a1 / (a3 - a1)))
-        self.assertAlmostEqual(duals[m.c2], 0)
-        self.assertAlmostEqual(duals[m.c3], a1 / (a3 - a1))
+        if opt_class != MAiNGO:
+            duals = opt.get_duals()
+            self.assertAlmostEqual(duals[m.c1], -(1 + a1 / (a3 - a1)))
+            self.assertAlmostEqual(duals[m.c2], 0)
+            self.assertAlmostEqual(duals[m.c3], a1 / (a3 - a1))
 
         del m.c3
         res = opt.solve(m)
@@ -435,9 +469,10 @@ def test_add_remove_cons(
         self.assertAlmostEqual(m.y.value, a1 * (b2 - b1) / (a1 - a2) + b1)
         self.assertAlmostEqual(res.best_feasible_objective, m.y.value)
         self.assertTrue(res.best_objective_bound <= m.y.value)
-        duals = opt.get_duals()
-        self.assertAlmostEqual(duals[m.c1], -(1 + a1 / (a2 - a1)))
-        self.assertAlmostEqual(duals[m.c2], a1 / (a2 - a1))
+        if opt_class != MAiNGO:
+            duals = opt.get_duals()
+            self.assertAlmostEqual(duals[m.c1], -(1 + a1 / (a2 - a1)))
+            self.assertAlmostEqual(duals[m.c2], a1 / (a2 - a1))
 
     @parameterized.expand(input=_load_tests(all_solvers, only_child_vars_options))
     def test_results_infeasible(
@@ -476,14 +511,15 @@ def test_results_infeasible(
             RuntimeError, '.*does not currently have a valid solution.*'
         ):
             res.solution_loader.load_vars()
-        with self.assertRaisesRegex(
-            RuntimeError, '.*does not currently have valid duals.*'
-        ):
-            res.solution_loader.get_duals()
-        with self.assertRaisesRegex(
-            RuntimeError, '.*does not currently have valid reduced costs.*'
-        ):
-            res.solution_loader.get_reduced_costs()
+        if opt_class != MAiNGO:
+            with self.assertRaisesRegex(
+                RuntimeError, '.*does not currently have valid duals.*'
+            ):
+                res.solution_loader.get_duals()
+            with self.assertRaisesRegex(
+                RuntimeError, '.*does not currently have valid reduced costs.*'
+            ):
+                res.solution_loader.get_reduced_costs()
 
     @parameterized.expand(input=_load_tests(all_solvers, only_child_vars_options))
     def test_duals(self, name: str, opt_class: Type[PersistentSolver], only_child_vars):
@@ -500,13 +536,14 @@ def test_duals(self, name: str, opt_class: Type[PersistentSolver], only_child_va
         res = opt.solve(m)
         self.assertAlmostEqual(m.x.value, 1)
         self.assertAlmostEqual(m.y.value, 1)
-        duals = opt.get_duals()
-        self.assertAlmostEqual(duals[m.c1], 0.5)
-        self.assertAlmostEqual(duals[m.c2], 0.5)
+        if opt_class != MAiNGO:
+            duals = opt.get_duals()
+            self.assertAlmostEqual(duals[m.c1], 0.5)
+            self.assertAlmostEqual(duals[m.c2], 0.5)
 
-        duals = opt.get_duals(cons_to_load=[m.c1])
-        self.assertAlmostEqual(duals[m.c1], 0.5)
-        self.assertNotIn(m.c2, duals)
+            duals = opt.get_duals(cons_to_load=[m.c1])
+            self.assertAlmostEqual(duals[m.c1], 0.5)
+            self.assertNotIn(m.c2, duals)
 
     @parameterized.expand(input=_load_tests(qcp_solvers, only_child_vars_options))
     def test_mutable_quadratic_coefficient(
@@ -661,7 +698,7 @@ def test_fixed_vars_4(
     ):
         opt: PersistentSolver = opt_class(only_child_vars=only_child_vars)
         opt.update_config.treat_fixed_vars_as_params = True
-        if not opt.available():
+        if not opt.available() or opt_class == MAiNGO:
             raise unittest.SkipTest
         m = pe.ConcreteModel()
         m.x = pe.Var()
@@ -754,17 +791,19 @@ def test_mutable_param_with_range(
                 self.assertAlmostEqual(m.y.value, a1 * (b2 - b1) / (a1 - a2) + b1, 6)
                 self.assertAlmostEqual(res.best_feasible_objective, m.y.value, 6)
                 self.assertTrue(res.best_objective_bound <= m.y.value + 1e-12)
-                duals = opt.get_duals()
-                self.assertAlmostEqual(duals[m.con1], (1 + a1 / (a2 - a1)), 6)
-                self.assertAlmostEqual(duals[m.con2], -a1 / (a2 - a1), 6)
+                if opt_class != MAiNGO:
+                    duals = opt.get_duals()
+                    self.assertAlmostEqual(duals[m.con1], (1 + a1 / (a2 - a1)), 6)
+                    self.assertAlmostEqual(duals[m.con2], -a1 / (a2 - a1), 6)
             else:
                 self.assertAlmostEqual(m.x.value, (c2 - c1) / (a1 - a2), 6)
                 self.assertAlmostEqual(m.y.value, a1 * (c2 - c1) / (a1 - a2) + c1, 6)
                 self.assertAlmostEqual(res.best_feasible_objective, m.y.value, 6)
                 self.assertTrue(res.best_objective_bound >= m.y.value - 1e-12)
-                duals = opt.get_duals()
-                self.assertAlmostEqual(duals[m.con1], (1 + a1 / (a2 - a1)), 6)
-                self.assertAlmostEqual(duals[m.con2], -a1 / (a2 - a1), 6)
+                if opt_class != MAiNGO:
+                    duals = opt.get_duals()
+                    self.assertAlmostEqual(duals[m.con1], (1 + a1 / (a2 - a1)), 6)
+                    self.assertAlmostEqual(duals[m.con2], -a1 / (a2 - a1), 6)
 
     @parameterized.expand(input=_load_tests(all_solvers, only_child_vars_options))
     def test_add_and_remove_vars(
@@ -826,13 +865,13 @@ def test_exp(self, name: str, opt_class: Type[PersistentSolver], only_child_vars
         m.obj = pe.Objective(expr=m.x**2 + m.y**2)
         m.c1 = pe.Constraint(expr=m.y >= pe.exp(m.x))
         res = opt.solve(m)
-        self.assertAlmostEqual(m.x.value, -0.42630274815985264)
-        self.assertAlmostEqual(m.y.value, 0.6529186341994245)
+        self.assertAlmostEqual(m.x.value, -0.42630274815985264, 6)
+        self.assertAlmostEqual(m.y.value, 0.6529186341994245, 6)
 
     @parameterized.expand(input=_load_tests(nlp_solvers, only_child_vars_options))
     def test_log(self, name: str, opt_class: Type[PersistentSolver], only_child_vars):
         opt = opt_class(only_child_vars=only_child_vars)
-        if not opt.available():
+        if not opt.available() or opt_class == MAiNGO:
             raise unittest.SkipTest
         m = pe.ConcreteModel()
         m.x = pe.Var(initialize=1)
@@ -907,6 +946,27 @@ def test_bounds_with_params(
         res = opt.solve(m)
         self.assertAlmostEqual(m.y.value, 3)
 
+    @parameterized.expand(input=_load_tests(all_solvers, only_child_vars_options))
+    def test_bounds_with_immutable_params(
+        self, name: str, opt_class: Type[PersistentSolver], only_child_vars
+    ):
+        # this test is for issue #2574
+        opt: PersistentSolver = opt_class(only_child_vars=only_child_vars)
+        if not opt.available():
+            raise unittest.SkipTest
+        m = pe.ConcreteModel()
+        m.p = pe.Param(mutable=False, initialize=1)
+        m.q = pe.Param([1, 2], mutable=False, initialize=10)
+        m.y = pe.Var()
+        m.y.setlb(m.p)
+        m.y.setub(m.q[1])
+        m.obj = pe.Objective(expr=m.y)
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.y.value, 1)
+        m.y.setlb(m.q[2])
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.y.value, 10)
+
     @parameterized.expand(input=_load_tests(all_solvers, only_child_vars_options))
     def test_solution_loader(
         self, name: str, opt_class: Type[PersistentSolver], only_child_vars
@@ -941,31 +1001,32 @@ def test_solution_loader(
         self.assertNotIn(m.x, primals)
         self.assertIn(m.y, primals)
         self.assertAlmostEqual(primals[m.y], 1)
-        reduced_costs = res.solution_loader.get_reduced_costs()
-        self.assertIn(m.x, reduced_costs)
-        self.assertIn(m.y, reduced_costs)
-        self.assertAlmostEqual(reduced_costs[m.x], 1)
-        self.assertAlmostEqual(reduced_costs[m.y], 0)
-        reduced_costs = res.solution_loader.get_reduced_costs([m.y])
-        self.assertNotIn(m.x, reduced_costs)
-        self.assertIn(m.y, reduced_costs)
-        self.assertAlmostEqual(reduced_costs[m.y], 0)
-        duals = res.solution_loader.get_duals()
-        self.assertIn(m.c1, duals)
-        self.assertIn(m.c2, duals)
-        self.assertAlmostEqual(duals[m.c1], 1)
-        self.assertAlmostEqual(duals[m.c2], 0)
-        duals = res.solution_loader.get_duals([m.c1])
-        self.assertNotIn(m.c2, duals)
-        self.assertIn(m.c1, duals)
-        self.assertAlmostEqual(duals[m.c1], 1)
+        if opt_class != MAiNGO:
+            reduced_costs = res.solution_loader.get_reduced_costs()
+            self.assertIn(m.x, reduced_costs)
+            self.assertIn(m.y, reduced_costs)
+            self.assertAlmostEqual(reduced_costs[m.x], 1)
+            self.assertAlmostEqual(reduced_costs[m.y], 0)
+            reduced_costs = res.solution_loader.get_reduced_costs([m.y])
+            self.assertNotIn(m.x, reduced_costs)
+            self.assertIn(m.y, reduced_costs)
+            self.assertAlmostEqual(reduced_costs[m.y], 0)
+            duals = res.solution_loader.get_duals()
+            self.assertIn(m.c1, duals)
+            self.assertIn(m.c2, duals)
+            self.assertAlmostEqual(duals[m.c1], 1)
+            self.assertAlmostEqual(duals[m.c2], 0)
+            duals = res.solution_loader.get_duals([m.c1])
+            self.assertNotIn(m.c2, duals)
+            self.assertIn(m.c1, duals)
+            self.assertAlmostEqual(duals[m.c1], 1)
 
     @parameterized.expand(input=_load_tests(all_solvers, only_child_vars_options))
     def test_time_limit(
         self, name: str, opt_class: Type[PersistentSolver], only_child_vars
     ):
         opt: PersistentSolver = opt_class(only_child_vars=only_child_vars)
-        if not opt.available():
+        if not opt.available() or opt_class == MAiNGO:
             raise unittest.SkipTest
         from sys import platform
 
@@ -1046,13 +1107,14 @@ def test_objective_changes(
         m.obj.sense = pe.maximize
         opt.config.load_solution = False
         res = opt.solve(m)
-        self.assertIn(
-            res.termination_condition,
-            {
-                TerminationCondition.unbounded,
-                TerminationCondition.infeasibleOrUnbounded,
-            },
-        )
+        if opt_class != MAiNGO:
+            self.assertIn(
+                res.termination_condition,
+                {
+                    TerminationCondition.unbounded,
+                    TerminationCondition.infeasibleOrUnbounded,
+                },
+            )
         m.obj.sense = pe.minimize
         opt.config.load_solution = True
         m.obj = pe.Objective(expr=m.x * m.y)
@@ -1149,19 +1211,19 @@ def test_fixed_binaries(
         m.c = pe.Constraint(expr=m.y >= m.x)
         m.x.fix(0)
         res = opt.solve(m)
-        self.assertAlmostEqual(res.best_feasible_objective, 0)
+        self.assertAlmostEqual(res.best_feasible_objective, 0, 5)
         m.x.fix(1)
         res = opt.solve(m)
-        self.assertAlmostEqual(res.best_feasible_objective, 1)
+        self.assertAlmostEqual(res.best_feasible_objective, 1, 5)
 
         opt: PersistentSolver = opt_class(only_child_vars=only_child_vars)
         opt.update_config.treat_fixed_vars_as_params = False
         m.x.fix(0)
         res = opt.solve(m)
-        self.assertAlmostEqual(res.best_feasible_objective, 0)
+        self.assertAlmostEqual(res.best_feasible_objective, 0, 5)
         m.x.fix(1)
         res = opt.solve(m)
-        self.assertAlmostEqual(res.best_feasible_objective, 1)
+        self.assertAlmostEqual(res.best_feasible_objective, 1, 5)
 
     @parameterized.expand(input=_load_tests(mip_solvers, only_child_vars_options))
     def test_with_gdp(
@@ -1185,16 +1247,16 @@ def test_with_gdp(
         pe.TransformationFactory("gdp.bigm").apply_to(m)
 
         res = opt.solve(m)
-        self.assertAlmostEqual(res.best_feasible_objective, 1)
-        self.assertAlmostEqual(m.x.value, 0)
-        self.assertAlmostEqual(m.y.value, 1)
+        self.assertAlmostEqual(res.best_feasible_objective, 1, 6)
+        self.assertAlmostEqual(m.x.value, 0, 6)
+        self.assertAlmostEqual(m.y.value, 1, 6)
 
         opt: PersistentSolver = opt_class(only_child_vars=only_child_vars)
         opt.use_extensions = True
         res = opt.solve(m)
-        self.assertAlmostEqual(res.best_feasible_objective, 1)
-        self.assertAlmostEqual(m.x.value, 0)
-        self.assertAlmostEqual(m.y.value, 1)
+        self.assertAlmostEqual(res.best_feasible_objective, 1, 6)
+        self.assertAlmostEqual(m.x.value, 0, 6)
+        self.assertAlmostEqual(m.y.value, 1, 6)
 
     @parameterized.expand(input=all_solvers)
     def test_variables_elsewhere(self, name: str, opt_class: Type[PersistentSolver]):
@@ -1327,7 +1389,8 @@ def test_param_updates(self, name: str, opt_class: Type[PersistentSolver]):
         m.obj = pe.Objective(expr=m.y)
         m.c1 = pe.Constraint(expr=(0, m.y - m.a1 * m.x - m.b1, None))
         m.c2 = pe.Constraint(expr=(None, -m.y + m.a2 * m.x + m.b2, 0))
-        m.dual = pe.Suffix(direction=pe.Suffix.IMPORT)
+        if opt_class != MAiNGO:
+            m.dual = pe.Suffix(direction=pe.Suffix.IMPORT)
 
         params_to_test = [(1, -1, 2, 1), (1, -2, 2, 1), (1, -1, 3, 1)]
         for a1, a2, b1, b2 in params_to_test:
@@ -1339,8 +1402,9 @@ def test_param_updates(self, name: str, opt_class: Type[PersistentSolver]):
             pe.assert_optimal_termination(res)
             self.assertAlmostEqual(m.x.value, (b2 - b1) / (a1 - a2))
             self.assertAlmostEqual(m.y.value, a1 * (b2 - b1) / (a1 - a2) + b1)
-            self.assertAlmostEqual(m.dual[m.c1], (1 + a1 / (a2 - a1)))
-            self.assertAlmostEqual(m.dual[m.c2], a1 / (a2 - a1))
+            if opt_class != MAiNGO:
+                self.assertAlmostEqual(m.dual[m.c1], (1 + a1 / (a2 - a1)))
+                self.assertAlmostEqual(m.dual[m.c2], a1 / (a2 - a1))
 
     @parameterized.expand(input=all_solvers)
     def test_load_solutions(self, name: str, opt_class: Type[PersistentSolver]):
@@ -1351,11 +1415,14 @@ def test_load_solutions(self, name: str, opt_class: Type[PersistentSolver]):
         m.x = pe.Var()
         m.obj = pe.Objective(expr=m.x)
         m.c = pe.Constraint(expr=(-1, m.x, 1))
-        m.dual = pe.Suffix(direction=pe.Suffix.IMPORT)
+        if opt_class != MAiNGO:
+            m.dual = pe.Suffix(direction=pe.Suffix.IMPORT)
         res = opt.solve(m, load_solutions=False)
         pe.assert_optimal_termination(res)
         self.assertIsNone(m.x.value)
-        self.assertNotIn(m.c, m.dual)
+        if opt_class != MAiNGO:
+            self.assertNotIn(m.c, m.dual)
         m.solutions.load_from(res)
         self.assertAlmostEqual(m.x.value, -1)
-        self.assertAlmostEqual(m.dual[m.c], 1)
+        if opt_class != MAiNGO:
+            self.assertAlmostEqual(m.dual[m.c], 1)
diff --git a/pyomo/contrib/appsi/solvers/tests/test_wntr_persistent.py b/pyomo/contrib/appsi/solvers/tests/test_wntr_persistent.py
index d250923f104..6fb25bfb529 100644
--- a/pyomo/contrib/appsi/solvers/tests/test_wntr_persistent.py
+++ b/pyomo/contrib/appsi/solvers/tests/test_wntr_persistent.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pe
 import pyomo.common.unittest as unittest
 from pyomo.contrib.appsi.base import TerminationCondition, Results, PersistentSolver
diff --git a/pyomo/contrib/appsi/solvers/wntr.py b/pyomo/contrib/appsi/solvers/wntr.py
index 0a358c6aedf..0a66cc640e5 100644
--- a/pyomo/contrib/appsi/solvers/wntr.py
+++ b/pyomo/contrib/appsi/solvers/wntr.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.contrib.appsi.base import (
     PersistentBase,
     PersistentSolver,
@@ -28,10 +39,10 @@
 from pyomo.common.collections import ComponentMap
 from pyomo.core.expr.numvalue import native_numeric_types
 from typing import Dict, Optional, List
-from pyomo.core.base.block import _BlockData
-from pyomo.core.base.var import _GeneralVarData
-from pyomo.core.base.param import _ParamData
-from pyomo.core.base.constraint import _GeneralConstraintData
+from pyomo.core.base.block import BlockData
+from pyomo.core.base.var import VarData
+from pyomo.core.base.param import ParamData
+from pyomo.core.base.constraint import ConstraintData
 from pyomo.common.timing import HierarchicalTimer
 from pyomo.core.base import SymbolMap, NumericLabeler, TextLabeler
 from pyomo.common.dependencies import attempt_import
@@ -158,14 +169,16 @@ def _solve(self, timer: HierarchicalTimer):
                 timer.stop('load solution')
             else:
                 raise RuntimeError(
-                    'A feasible solution was not found, so no solution can be loaded.'
-                    'Please set opt.config.load_solution=False and check '
-                    'results.termination_condition and '
+                    'A feasible solution was not found, so no solution can be loaded. '
+                    'If using the appsi.solvers.Wntr interface, you can '
+                    'set opt.config.load_solution=False. If using the environ.SolverFactory '
+                    'interface, you can set opt.solve(model, load_solutions = False). '
+                    'Then you can check results.termination_condition and '
                     'results.best_feasible_objective before loading a solution.'
                 )
         return results
 
-    def solve(self, model: _BlockData, timer: HierarchicalTimer = None) -> Results:
+    def solve(self, model: BlockData, timer: HierarchicalTimer = None) -> Results:
         StaleFlagManager.mark_all_as_stale()
         if self._last_results_object is not None:
             self._last_results_object.solution_loader.invalidate()
@@ -226,7 +239,7 @@ def set_instance(self, model):
 
         self.add_block(model)
 
-    def _add_variables(self, variables: List[_GeneralVarData]):
+    def _add_variables(self, variables: List[VarData]):
         aml = wntr.sim.aml.aml
         for var in variables:
             varname = self._symbol_map.getSymbol(var, self._labeler)
@@ -257,7 +270,7 @@ def _add_variables(self, variables: List[_GeneralVarData]):
                 )
             self._needs_updated = True
 
-    def _add_params(self, params: List[_ParamData]):
+    def _add_params(self, params: List[ParamData]):
         aml = wntr.sim.aml.aml
         for p in params:
             pname = self._symbol_map.getSymbol(p, self._labeler)
@@ -265,7 +278,7 @@ def _add_params(self, params: List[_ParamData]):
             setattr(self._solver_model, pname, wntr_p)
             self._pyomo_param_to_solver_param_map[id(p)] = wntr_p
 
-    def _add_constraints(self, cons: List[_GeneralConstraintData]):
+    def _add_constraints(self, cons: List[ConstraintData]):
         aml = wntr.sim.aml.aml
         for con in cons:
             if not con.equality:
@@ -281,7 +294,7 @@ def _add_constraints(self, cons: List[_GeneralConstraintData]):
             self._pyomo_con_to_solver_con_map[con] = wntr_con
             self._needs_updated = True
 
-    def _remove_constraints(self, cons: List[_GeneralConstraintData]):
+    def _remove_constraints(self, cons: List[ConstraintData]):
         for con in cons:
             solver_con = self._pyomo_con_to_solver_con_map[con]
             delattr(self._solver_model, solver_con.name)
@@ -289,7 +302,7 @@ def _remove_constraints(self, cons: List[_GeneralConstraintData]):
             del self._pyomo_con_to_solver_con_map[con]
             self._needs_updated = True
 
-    def _remove_variables(self, variables: List[_GeneralVarData]):
+    def _remove_variables(self, variables: List[VarData]):
         for var in variables:
             v_id = id(var)
             solver_var = self._pyomo_var_to_solver_var_map[v_id]
@@ -301,7 +314,7 @@ def _remove_variables(self, variables: List[_GeneralVarData]):
                 del self._solver_model._wntr_fixed_var_cons[v_id]
             self._needs_updated = True
 
-    def _remove_params(self, params: List[_ParamData]):
+    def _remove_params(self, params: List[ParamData]):
         for p in params:
             p_id = id(p)
             solver_param = self._pyomo_param_to_solver_param_map[p_id]
@@ -309,7 +322,7 @@ def _remove_params(self, params: List[_ParamData]):
             self._symbol_map.removeSymbol(p)
             del self._pyomo_param_to_solver_param_map[p_id]
 
-    def _update_variables(self, variables: List[_GeneralVarData]):
+    def _update_variables(self, variables: List[VarData]):
         aml = wntr.sim.aml.aml
         for var in variables:
             v_id = id(var)
diff --git a/pyomo/contrib/appsi/tests/__init__.py b/pyomo/contrib/appsi/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/appsi/tests/__init__.py
+++ b/pyomo/contrib/appsi/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/appsi/tests/test_base.py b/pyomo/contrib/appsi/tests/test_base.py
index 0d67ca4d01a..e537cc0f219 100644
--- a/pyomo/contrib/appsi/tests/test_base.py
+++ b/pyomo/contrib/appsi/tests/test_base.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.common import unittest
 from pyomo.contrib import appsi
 import pyomo.environ as pe
diff --git a/pyomo/contrib/appsi/tests/test_fbbt.py b/pyomo/contrib/appsi/tests/test_fbbt.py
index f92960769cf..97af611c572 100644
--- a/pyomo/contrib/appsi/tests/test_fbbt.py
+++ b/pyomo/contrib/appsi/tests/test_fbbt.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.common import unittest
 import pyomo.environ as pyo
 from pyomo.contrib import appsi
@@ -140,3 +151,16 @@ def test_named_exprs(self):
         for x in m.x.values():
             self.assertAlmostEqual(x.lb, 0)
             self.assertAlmostEqual(x.ub, 0)
+
+    def test_named_exprs_nest(self):
+        # test for issue #3184
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.e = pe.Expression(expr=m.x + 1)
+        m.f = pe.Expression(expr=m.e)
+        m.c = pe.Constraint(expr=(0, m.f, 0))
+        it = appsi.fbbt.IntervalTightener()
+        it.perform_fbbt(m)
+        for x in m.x.values():
+            self.assertAlmostEqual(x.lb, -1)
+            self.assertAlmostEqual(x.ub, -1)
diff --git a/pyomo/contrib/appsi/tests/test_interval.py b/pyomo/contrib/appsi/tests/test_interval.py
index 7963cc31665..2184f69621a 100644
--- a/pyomo/contrib/appsi/tests/test_interval.py
+++ b/pyomo/contrib/appsi/tests/test_interval.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.contrib.appsi.cmodel import cmodel, cmodel_available
 import pyomo.common.unittest as unittest
 import math
diff --git a/pyomo/contrib/appsi/utils/__init__.py b/pyomo/contrib/appsi/utils/__init__.py
index f665736fd4a..e1278431835 100644
--- a/pyomo/contrib/appsi/utils/__init__.py
+++ b/pyomo/contrib/appsi/utils/__init__.py
@@ -1,2 +1,13 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from .get_objective import get_objective
 from .collect_vars_and_named_exprs import collect_vars_and_named_exprs
diff --git a/pyomo/contrib/appsi/utils/collect_vars_and_named_exprs.py b/pyomo/contrib/appsi/utils/collect_vars_and_named_exprs.py
index 9027080f08c..4e117b04094 100644
--- a/pyomo/contrib/appsi/utils/collect_vars_and_named_exprs.py
+++ b/pyomo/contrib/appsi/utils/collect_vars_and_named_exprs.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.core.expr.visitor import ExpressionValueVisitor, nonpyomo_leaf_types
 import pyomo.core.expr as EXPR
 
diff --git a/pyomo/contrib/appsi/utils/get_objective.py b/pyomo/contrib/appsi/utils/get_objective.py
index 30dd911f9c8..110c0188d16 100644
--- a/pyomo/contrib/appsi/utils/get_objective.py
+++ b/pyomo/contrib/appsi/utils/get_objective.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.core.base.objective import Objective
 
 
diff --git a/pyomo/contrib/appsi/utils/tests/__init__.py b/pyomo/contrib/appsi/utils/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/appsi/utils/tests/__init__.py
+++ b/pyomo/contrib/appsi/utils/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/appsi/utils/tests/test_collect_vars_and_named_exprs.py b/pyomo/contrib/appsi/utils/tests/test_collect_vars_and_named_exprs.py
index 4c2a167a017..62f98728850 100644
--- a/pyomo/contrib/appsi/utils/tests/test_collect_vars_and_named_exprs.py
+++ b/pyomo/contrib/appsi/utils/tests/test_collect_vars_and_named_exprs.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.common import unittest
 import pyomo.environ as pe
 from pyomo.contrib.appsi.utils import collect_vars_and_named_exprs
diff --git a/pyomo/contrib/appsi/writers/__init__.py b/pyomo/contrib/appsi/writers/__init__.py
index eeadfa73d03..18f90e8aa96 100644
--- a/pyomo/contrib/appsi/writers/__init__.py
+++ b/pyomo/contrib/appsi/writers/__init__.py
@@ -1,2 +1,13 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from .nl_writer import NLWriter
 from .lp_writer import LPWriter
diff --git a/pyomo/contrib/appsi/writers/config.py b/pyomo/contrib/appsi/writers/config.py
index 7a7faadaabe..32d45325e96 100644
--- a/pyomo/contrib/appsi/writers/config.py
+++ b/pyomo/contrib/appsi/writers/config.py
@@ -1,3 +1,15 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+
 class WriterConfig(object):
     def __init__(self):
         self.symbolic_solver_labels = False
diff --git a/pyomo/contrib/appsi/writers/lp_writer.py b/pyomo/contrib/appsi/writers/lp_writer.py
index 8a76fa5f9eb..788dfde7892 100644
--- a/pyomo/contrib/appsi/writers/lp_writer.py
+++ b/pyomo/contrib/appsi/writers/lp_writer.py
@@ -1,10 +1,21 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from typing import List
-from pyomo.core.base.param import _ParamData
-from pyomo.core.base.var import _GeneralVarData
-from pyomo.core.base.constraint import _GeneralConstraintData
-from pyomo.core.base.objective import _GeneralObjectiveData
-from pyomo.core.base.sos import _SOSConstraintData
-from pyomo.core.base.block import _BlockData
+from pyomo.core.base.param import ParamData
+from pyomo.core.base.var import VarData
+from pyomo.core.base.constraint import ConstraintData
+from pyomo.core.base.objective import ObjectiveData
+from pyomo.core.base.sos import SOSConstraintData
+from pyomo.core.base.block import BlockData
 from pyomo.repn.standard_repn import generate_standard_repn
 from pyomo.core.expr.numvalue import value
 from pyomo.contrib.appsi.base import PersistentBase
@@ -66,7 +77,7 @@ def set_instance(self, model):
         if self._objective is None:
             self.set_objective(None)
 
-    def _add_variables(self, variables: List[_GeneralVarData]):
+    def _add_variables(self, variables: List[VarData]):
         cmodel.process_pyomo_vars(
             self._expr_types,
             variables,
@@ -80,7 +91,7 @@ def _add_variables(self, variables: List[_GeneralVarData]):
             False,
         )
 
-    def _add_params(self, params: List[_ParamData]):
+    def _add_params(self, params: List[ParamData]):
         cparams = cmodel.create_params(len(params))
         for ndx, p in enumerate(params):
             cp = cparams[ndx]
@@ -88,36 +99,36 @@ def _add_params(self, params: List[_ParamData]):
             cp.value = p.value
             self._pyomo_param_to_solver_param_map[id(p)] = cp
 
-    def _add_constraints(self, cons: List[_GeneralConstraintData]):
+    def _add_constraints(self, cons: List[ConstraintData]):
         cmodel.process_lp_constraints(cons, self)
 
-    def _add_sos_constraints(self, cons: List[_SOSConstraintData]):
+    def _add_sos_constraints(self, cons: List[SOSConstraintData]):
         if len(cons) != 0:
             raise NotImplementedError('LP writer does not yet support SOS constraints')
 
-    def _remove_constraints(self, cons: List[_GeneralConstraintData]):
+    def _remove_constraints(self, cons: List[ConstraintData]):
         for c in cons:
             cc = self._pyomo_con_to_solver_con_map.pop(c)
             self._writer.remove_constraint(cc)
             self._symbol_map.removeSymbol(c)
             del self._solver_con_to_pyomo_con_map[cc]
 
-    def _remove_sos_constraints(self, cons: List[_SOSConstraintData]):
+    def _remove_sos_constraints(self, cons: List[SOSConstraintData]):
         if len(cons) != 0:
             raise NotImplementedError('LP writer does not yet support SOS constraints')
 
-    def _remove_variables(self, variables: List[_GeneralVarData]):
+    def _remove_variables(self, variables: List[VarData]):
         for v in variables:
             cvar = self._pyomo_var_to_solver_var_map.pop(id(v))
             del self._solver_var_to_pyomo_var_map[cvar]
             self._symbol_map.removeSymbol(v)
 
-    def _remove_params(self, params: List[_ParamData]):
+    def _remove_params(self, params: List[ParamData]):
         for p in params:
             del self._pyomo_param_to_solver_param_map[id(p)]
             self._symbol_map.removeSymbol(p)
 
-    def _update_variables(self, variables: List[_GeneralVarData]):
+    def _update_variables(self, variables: List[VarData]):
         cmodel.process_pyomo_vars(
             self._expr_types,
             variables,
@@ -136,7 +147,7 @@ def update_params(self):
             cp = self._pyomo_param_to_solver_param_map[p_id]
             cp.value = p.value
 
-    def _set_objective(self, obj: _GeneralObjectiveData):
+    def _set_objective(self, obj: ObjectiveData):
         cobj = cmodel.process_lp_objective(
             self._expr_types,
             obj,
@@ -156,7 +167,7 @@ def _set_objective(self, obj: _GeneralObjectiveData):
         cobj.name = cname
         self._writer.objective = cobj
 
-    def write(self, model: _BlockData, filename: str, timer: HierarchicalTimer = None):
+    def write(self, model: BlockData, filename: str, timer: HierarchicalTimer = None):
         if timer is None:
             timer = HierarchicalTimer()
         if model is not self._model:
diff --git a/pyomo/contrib/appsi/writers/nl_writer.py b/pyomo/contrib/appsi/writers/nl_writer.py
index 9c739fd6ebb..27cdca004cb 100644
--- a/pyomo/contrib/appsi/writers/nl_writer.py
+++ b/pyomo/contrib/appsi/writers/nl_writer.py
@@ -1,10 +1,21 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from typing import List
-from pyomo.core.base.param import _ParamData
-from pyomo.core.base.var import _GeneralVarData
-from pyomo.core.base.constraint import _GeneralConstraintData
-from pyomo.core.base.objective import _GeneralObjectiveData
-from pyomo.core.base.sos import _SOSConstraintData
-from pyomo.core.base.block import _BlockData
+from pyomo.core.base.param import ParamData
+from pyomo.core.base.var import VarData
+from pyomo.core.base.constraint import ConstraintData
+from pyomo.core.base.objective import ObjectiveData
+from pyomo.core.base.sos import SOSConstraintData
+from pyomo.core.base.block import BlockData
 from pyomo.repn.standard_repn import generate_standard_repn
 from pyomo.core.expr.numvalue import value
 from pyomo.contrib.appsi.base import PersistentBase
@@ -67,7 +78,7 @@ def set_instance(self, model):
             self.set_objective(None)
         self._set_pyomo_amplfunc_env()
 
-    def _add_variables(self, variables: List[_GeneralVarData]):
+    def _add_variables(self, variables: List[VarData]):
         if self.config.symbolic_solver_labels:
             set_name = True
             symbol_map = self._symbol_map
@@ -89,7 +100,7 @@ def _add_variables(self, variables: List[_GeneralVarData]):
             False,
         )
 
-    def _add_params(self, params: List[_ParamData]):
+    def _add_params(self, params: List[ParamData]):
         cparams = cmodel.create_params(len(params))
         for ndx, p in enumerate(params):
             cp = cparams[ndx]
@@ -100,7 +111,7 @@ def _add_params(self, params: List[_ParamData]):
                 cp = cparams[ndx]
                 cp.name = self._symbol_map.getSymbol(p, self._param_labeler)
 
-    def _add_constraints(self, cons: List[_GeneralConstraintData]):
+    def _add_constraints(self, cons: List[ConstraintData]):
         cmodel.process_nl_constraints(
             self._writer,
             self._expr_types,
@@ -115,11 +126,11 @@ def _add_constraints(self, cons: List[_GeneralConstraintData]):
             for c, cc in self._pyomo_con_to_solver_con_map.items():
                 cc.name = self._symbol_map.getSymbol(c, self._con_labeler)
 
-    def _add_sos_constraints(self, cons: List[_SOSConstraintData]):
+    def _add_sos_constraints(self, cons: List[SOSConstraintData]):
         if len(cons) != 0:
             raise NotImplementedError('NL writer does not support SOS constraints')
 
-    def _remove_constraints(self, cons: List[_GeneralConstraintData]):
+    def _remove_constraints(self, cons: List[ConstraintData]):
         if self.config.symbolic_solver_labels:
             for c in cons:
                 self._symbol_map.removeSymbol(c)
@@ -129,11 +140,11 @@ def _remove_constraints(self, cons: List[_GeneralConstraintData]):
             self._writer.remove_constraint(cc)
             del self._solver_con_to_pyomo_con_map[cc]
 
-    def _remove_sos_constraints(self, cons: List[_SOSConstraintData]):
+    def _remove_sos_constraints(self, cons: List[SOSConstraintData]):
         if len(cons) != 0:
             raise NotImplementedError('NL writer does not support SOS constraints')
 
-    def _remove_variables(self, variables: List[_GeneralVarData]):
+    def _remove_variables(self, variables: List[VarData]):
         if self.config.symbolic_solver_labels:
             for v in variables:
                 self._symbol_map.removeSymbol(v)
@@ -142,7 +153,7 @@ def _remove_variables(self, variables: List[_GeneralVarData]):
             cvar = self._pyomo_var_to_solver_var_map.pop(id(v))
             del self._solver_var_to_pyomo_var_map[cvar]
 
-    def _remove_params(self, params: List[_ParamData]):
+    def _remove_params(self, params: List[ParamData]):
         if self.config.symbolic_solver_labels:
             for p in params:
                 self._symbol_map.removeSymbol(p)
@@ -150,7 +161,7 @@ def _remove_params(self, params: List[_ParamData]):
         for p in params:
             del self._pyomo_param_to_solver_param_map[id(p)]
 
-    def _update_variables(self, variables: List[_GeneralVarData]):
+    def _update_variables(self, variables: List[VarData]):
         cmodel.process_pyomo_vars(
             self._expr_types,
             variables,
@@ -169,7 +180,7 @@ def update_params(self):
             cp = self._pyomo_param_to_solver_param_map[p_id]
             cp.value = p.value
 
-    def _set_objective(self, obj: _GeneralObjectiveData):
+    def _set_objective(self, obj: ObjectiveData):
         if obj is None:
             const = cmodel.Constant(0)
             lin_vars = list()
@@ -221,7 +232,7 @@ def _set_objective(self, obj: _GeneralObjectiveData):
         cobj.sense = sense
         self._writer.objective = cobj
 
-    def write(self, model: _BlockData, filename: str, timer: HierarchicalTimer = None):
+    def write(self, model: BlockData, filename: str, timer: HierarchicalTimer = None):
         if timer is None:
             timer = HierarchicalTimer()
         if model is not self._model:
diff --git a/pyomo/contrib/appsi/writers/tests/__init__.py b/pyomo/contrib/appsi/writers/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/appsi/writers/tests/__init__.py
+++ b/pyomo/contrib/appsi/writers/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/appsi/writers/tests/test_nl_writer.py b/pyomo/contrib/appsi/writers/tests/test_nl_writer.py
index 3b61a5901c3..c6005afceb2 100644
--- a/pyomo/contrib/appsi/writers/tests/test_nl_writer.py
+++ b/pyomo/contrib/appsi/writers/tests/test_nl_writer.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.common.unittest as unittest
 from pyomo.common.tempfiles import TempfileManager
 import pyomo.environ as pe
diff --git a/pyomo/contrib/benders/__init__.py b/pyomo/contrib/benders/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/benders/__init__.py
+++ b/pyomo/contrib/benders/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/benders/benders_cuts.py b/pyomo/contrib/benders/benders_cuts.py
index 5eb2e91cc82..0653be55986 100644
--- a/pyomo/contrib/benders/benders_cuts.py
+++ b/pyomo/contrib/benders/benders_cuts.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,7 +9,7 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-from pyomo.core.base.block import _BlockData, declare_custom_block
+from pyomo.core.base.block import BlockData, declare_custom_block
 import pyomo.environ as pyo
 from pyomo.solvers.plugins.solvers.persistent_solver import PersistentSolver
 from pyomo.core.expr.visitor import identify_variables
@@ -166,13 +166,13 @@ def _setup_subproblem(b, root_vars, relax_subproblem_cons):
 
 
 @declare_custom_block(name='BendersCutGenerator')
-class BendersCutGeneratorData(_BlockData):
+class BendersCutGeneratorData(BlockData):
     def __init__(self, component):
         if not mpi4py_available:
             raise ImportError('BendersCutGenerator requires mpi4py.')
         if not numpy_available:
             raise ImportError('BendersCutGenerator requires numpy.')
-        _BlockData.__init__(self, component)
+        BlockData.__init__(self, component)
 
         self.num_subproblems_by_rank = 0  # np.zeros(self.comm.Get_size())
         self.subproblems = list()
@@ -335,7 +335,6 @@ def generate_cut(self):
                     subproblem_solver.remove_constraint(c)
                 subproblem_solver.remove_constraint(subproblem.fix_eta)
             del subproblem.fix_complicating_vars
-            del subproblem.fix_complicating_vars_index
             del subproblem.fix_eta
 
         total_num_subproblems = self.global_num_subproblems()
diff --git a/pyomo/contrib/benders/examples/__init__.py b/pyomo/contrib/benders/examples/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/benders/examples/__init__.py
+++ b/pyomo/contrib/benders/examples/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/benders/examples/farmer.py b/pyomo/contrib/benders/examples/farmer.py
index bf5d40e112c..47cdb3511a3 100644
--- a/pyomo/contrib/benders/examples/farmer.py
+++ b/pyomo/contrib/benders/examples/farmer.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/benders/examples/grothey_ex.py b/pyomo/contrib/benders/examples/grothey_ex.py
index 66457fa7293..27d37cac124 100644
--- a/pyomo/contrib/benders/examples/grothey_ex.py
+++ b/pyomo/contrib/benders/examples/grothey_ex.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/benders/tests/__init__.py b/pyomo/contrib/benders/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/benders/tests/__init__.py
+++ b/pyomo/contrib/benders/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/benders/tests/test_benders.py b/pyomo/contrib/benders/tests/test_benders.py
index 26a2a0b7910..d985f886c10 100644
--- a/pyomo/contrib/benders/tests/test_benders.py
+++ b/pyomo/contrib/benders/tests/test_benders.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -10,35 +10,24 @@
 #  ___________________________________________________________________________
 
 import pyomo.common.unittest as unittest
-from pyomo.contrib.benders.benders_cuts import BendersCutGenerator
 import pyomo.environ as pyo
 
-try:
-    import mpi4py
-
-    mpi4py_available = True
-except:
-    mpi4py_available = False
-try:
-    import numpy as np
-
-    numpy_available = True
-except:
-    numpy_available = False
-
+from pyomo.common.dependencies import mpi4py_available, numpy_available
+from pyomo.contrib.benders.benders_cuts import BendersCutGenerator
 
-ipopt_opt = pyo.SolverFactory('ipopt')
-ipopt_available = ipopt_opt.available(exception_flag=False)
+ipopt_available = pyo.SolverFactory('ipopt').available(exception_flag=False)
 
-cplex_opt = pyo.SolverFactory('cplex_direct')
-cplex_available = cplex_opt.available(exception_flag=False)
+for mip_name in ('cplex_direct', 'gurobi_direct', 'gurobi', 'cplex', 'glpk', 'cbc'):
+    mip_available = pyo.SolverFactory(mip_name).available(exception_flag=False)
+    if mip_available:
+        break
 
 
 @unittest.pytest.mark.mpi
 class MPITestBenders(unittest.TestCase):
     @unittest.skipIf(not mpi4py_available, 'mpi4py is not available.')
     @unittest.skipIf(not numpy_available, 'numpy is not available.')
-    @unittest.skipIf(not cplex_available, 'cplex is not available.')
+    @unittest.skipIf(not mip_available, 'MIP solver is not available.')
     def test_farmer(self):
         class Farmer(object):
             def __init__(self):
@@ -200,9 +189,9 @@ def EnforceQuotas_rule(m, i):
                 subproblem_fn=create_subproblem,
                 subproblem_fn_kwargs=subproblem_fn_kwargs,
                 root_eta=m.eta[s],
-                subproblem_solver='cplex_direct',
+                subproblem_solver=mip_name,
             )
-        opt = pyo.SolverFactory('cplex_direct')
+        opt = pyo.SolverFactory(mip_name)
 
         for i in range(30):
             res = opt.solve(m, tee=False)
@@ -261,7 +250,7 @@ def create_subproblem(root):
 
     @unittest.skipIf(not mpi4py_available, 'mpi4py is not available.')
     @unittest.skipIf(not numpy_available, 'numpy is not available.')
-    @unittest.skipIf(not cplex_available, 'cplex is not available.')
+    @unittest.skipIf(not mip_available, 'MIP solver is not available.')
     def test_four_scen_farmer(self):
         class FourScenFarmer(object):
             def __init__(self):
@@ -430,9 +419,9 @@ def EnforceQuotas_rule(m, i):
                 subproblem_fn=create_subproblem,
                 subproblem_fn_kwargs=subproblem_fn_kwargs,
                 root_eta=m.eta[s],
-                subproblem_solver='cplex_direct',
+                subproblem_solver=mip_name,
             )
-        opt = pyo.SolverFactory('cplex_direct')
+        opt = pyo.SolverFactory(mip_name)
 
         for i in range(30):
             res = opt.solve(m, tee=False)
diff --git a/pyomo/contrib/community_detection/__init__.py b/pyomo/contrib/community_detection/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/community_detection/__init__.py
+++ b/pyomo/contrib/community_detection/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/community_detection/community_graph.py b/pyomo/contrib/community_detection/community_graph.py
index f0a1f9149bd..889940b5996 100644
--- a/pyomo/contrib/community_detection/community_graph.py
+++ b/pyomo/contrib/community_detection/community_graph.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """Model Graph Generator Code"""
 
 from pyomo.common.dependencies import networkx as nx
diff --git a/pyomo/contrib/community_detection/detection.py b/pyomo/contrib/community_detection/detection.py
index c5366394530..db3bb8f5a20 100644
--- a/pyomo/contrib/community_detection/detection.py
+++ b/pyomo/contrib/community_detection/detection.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """
 Main module for community detection integration with Pyomo models.
 
@@ -20,7 +31,7 @@
     Objective,
     ConstraintList,
 )
-from pyomo.core.base.objective import _GeneralObjectiveData
+from pyomo.core.base.objective import ObjectiveData
 from pyomo.core.expr.visitor import replace_expressions, identify_variables
 from pyomo.contrib.community_detection.community_graph import generate_model_graph
 from pyomo.common.dependencies import networkx as nx
@@ -569,7 +580,7 @@ def visualize_model_graph(
                 pos = nx.spring_layout(model_graph)
 
         # Define color_map
-        color_map = plt.cm.get_cmap('viridis', len(numbered_community_map))
+        color_map = plt.get_cmap('viridis', len(numbered_community_map))
 
         # Create the figure and draw the graph
         fig = plt.figure()
@@ -739,7 +750,7 @@ def generate_structured_model(self):
                 # Check to see whether 'stored_constraint' is actually an objective (since constraints and objectives
                 # grouped together)
                 if self.with_objective and isinstance(
-                    stored_constraint, (_GeneralObjectiveData, Objective)
+                    stored_constraint, (ObjectiveData, Objective)
                 ):
                     # If the constraint is actually an objective, we add it to the block as an objective
                     new_objective = Objective(
diff --git a/pyomo/contrib/community_detection/event_log.py b/pyomo/contrib/community_detection/event_log.py
index 30e28257de8..767ff0f50f5 100644
--- a/pyomo/contrib/community_detection/event_log.py
+++ b/pyomo/contrib/community_detection/event_log.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """ Logger function for community_graph.py """
 
 from logging import getLogger
diff --git a/pyomo/contrib/community_detection/plugins.py b/pyomo/contrib/community_detection/plugins.py
index 0cdc95ad02a..229b7255a27 100644
--- a/pyomo/contrib/community_detection/plugins.py
+++ b/pyomo/contrib/community_detection/plugins.py
@@ -1,2 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+
 def load():
     import pyomo.contrib.community_detection.detection
diff --git a/pyomo/contrib/community_detection/tests/__init__.py b/pyomo/contrib/community_detection/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/community_detection/tests/__init__.py
+++ b/pyomo/contrib/community_detection/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/community_detection/tests/test_detection.py b/pyomo/contrib/community_detection/tests/test_detection.py
index acfd441005f..6a43ea1b61a 100644
--- a/pyomo/contrib/community_detection/tests/test_detection.py
+++ b/pyomo/contrib/community_detection/tests/test_detection.py
@@ -4,7 +4,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/cp/__init__.py b/pyomo/contrib/cp/__init__.py
index c51160bf931..d206fe95251 100644
--- a/pyomo/contrib/cp/__init__.py
+++ b/pyomo/contrib/cp/__init__.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.contrib.cp.interval_var import (
     IntervalVar,
     IntervalVarStartTime,
@@ -6,6 +17,19 @@
     IntervalVarPresence,
 )
 from pyomo.contrib.cp.repn.docplex_writer import DocplexWriter, CPOptimizerSolver
+from pyomo.contrib.cp.sequence_var import SequenceVar
+from pyomo.contrib.cp.scheduling_expr.sequence_expressions import (
+    no_overlap,
+    first_in_sequence,
+    last_in_sequence,
+    before_in_sequence,
+    predecessor_to,
+)
+from pyomo.contrib.cp.scheduling_expr.scheduling_logic import (
+    alternative,
+    spans,
+    synchronize,
+)
 from pyomo.contrib.cp.scheduling_expr.step_function_expressions import (
     AlwaysIn,
     Step,
diff --git a/pyomo/contrib/cp/interval_var.py b/pyomo/contrib/cp/interval_var.py
index 4e22c2b2d3d..dec5af74d9f 100644
--- a/pyomo/contrib/cp/interval_var.py
+++ b/pyomo/contrib/cp/interval_var.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -11,6 +11,7 @@
 
 from pyomo.common.collections import ComponentSet
 from pyomo.common.pyomo_typing import overload
+from pyomo.contrib.cp.scheduling_expr.scheduling_logic import SpanExpression
 from pyomo.contrib.cp.scheduling_expr.precedence_expressions import (
     BeforeExpression,
     AtExpression,
@@ -18,12 +19,13 @@
 
 from pyomo.core import Integers, value
 from pyomo.core.base import Any, ScalarVar, ScalarBooleanVar
-from pyomo.core.base.block import _BlockData, Block
+from pyomo.core.base.block import BlockData, Block
 from pyomo.core.base.component import ModelComponentFactory
 from pyomo.core.base.global_set import UnindexedComponent_index
 from pyomo.core.base.indexed_component import IndexedComponent, UnindexedComponent_set
 from pyomo.core.base.initializer import BoundInitializer, Initializer
 from pyomo.core.expr import GetItemExpression
+from pyomo.core.expr.logical_expr import _flattened
 
 
 class IntervalVarTimePoint(ScalarVar):
@@ -49,7 +51,7 @@ class IntervalVarStartTime(IntervalVarTimePoint):
     """This class defines a single variable denoting a start time point
     of an IntervalVar"""
 
-    def __init__(self):
+    def __init__(self, *args, **kwd):
         super().__init__(domain=Integers, ctype=IntervalVarStartTime)
 
 
@@ -57,7 +59,7 @@ class IntervalVarEndTime(IntervalVarTimePoint):
     """This class defines a single variable denoting an end time point
     of an IntervalVar"""
 
-    def __init__(self):
+    def __init__(self, *args, **kwd):
         super().__init__(domain=Integers, ctype=IntervalVarEndTime)
 
 
@@ -67,7 +69,7 @@ class IntervalVarLength(ScalarVar):
 
     __slots__ = ()
 
-    def __init__(self):
+    def __init__(self, *args, **kwd):
         super().__init__(domain=Integers, ctype=IntervalVarLength)
 
     def get_associated_interval_var(self):
@@ -80,21 +82,23 @@ class IntervalVarPresence(ScalarBooleanVar):
 
     __slots__ = ()
 
-    def __init__(self):
+    def __init__(self, *args, **kwd):
+        # TODO: adding args and kwd above made Reference work, but we
+        # probably shouldn't just swallow them, right?
         super().__init__(ctype=IntervalVarPresence)
 
     def get_associated_interval_var(self):
         return self.parent_block()
 
 
-class IntervalVarData(_BlockData):
+class IntervalVarData(BlockData):
     """This class defines the abstract interface for a single interval variable."""
 
     # We will put our four variables on this, and everything else is off limits.
     _Block_reserved_words = Any
 
     def __init__(self, component=None):
-        _BlockData.__init__(self, component)
+        BlockData.__init__(self, component)
 
         with self._declare_reserved_components():
             self.is_present = IntervalVarPresence()
@@ -122,6 +126,9 @@ def optional(self, val):
         else:
             self.is_present.fix(True)
 
+    def spans(self, *args):
+        return SpanExpression([self] + list(_flattened(args)))
+
 
 @ModelComponentFactory.register("Interval variables for scheduling.")
 class IntervalVar(Block):
diff --git a/pyomo/contrib/cp/plugins.py b/pyomo/contrib/cp/plugins.py
index 445599daab0..b0f7c84eb65 100644
--- a/pyomo/contrib/cp/plugins.py
+++ b/pyomo/contrib/cp/plugins.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/cp/repn/__init__.py b/pyomo/contrib/cp/repn/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/cp/repn/__init__.py
+++ b/pyomo/contrib/cp/repn/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/cp/repn/docplex_writer.py b/pyomo/contrib/cp/repn/docplex_writer.py
index 51c3f66140e..6a0eb7749a8 100644
--- a/pyomo/contrib/cp/repn/docplex_writer.py
+++ b/pyomo/contrib/cp/repn/docplex_writer.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -30,10 +30,27 @@
     IntervalVarData,
     IndexedIntervalVar,
 )
+from pyomo.contrib.cp.sequence_var import (
+    SequenceVar,
+    ScalarSequenceVar,
+    SequenceVarData,
+)
+from pyomo.contrib.cp.scheduling_expr.scheduling_logic import (
+    AlternativeExpression,
+    SpanExpression,
+    SynchronizeExpression,
+)
 from pyomo.contrib.cp.scheduling_expr.precedence_expressions import (
     BeforeExpression,
     AtExpression,
 )
+from pyomo.contrib.cp.scheduling_expr.sequence_expressions import (
+    NoOverlapExpression,
+    FirstInSequenceExpression,
+    LastInSequenceExpression,
+    BeforeInSequenceExpression,
+    PredecessorToExpression,
+)
 from pyomo.contrib.cp.scheduling_expr.step_function_expressions import (
     AlwaysIn,
     StepAt,
@@ -60,16 +77,17 @@
 )
 from pyomo.core.base.boolean_var import (
     ScalarBooleanVar,
-    _GeneralBooleanVarData,
+    BooleanVarData,
     IndexedBooleanVar,
 )
-from pyomo.core.base.expression import ScalarExpression, _GeneralExpressionData
-from pyomo.core.base.param import IndexedParam, ScalarParam
-from pyomo.core.base.var import ScalarVar, _GeneralVarData, IndexedVar
+from pyomo.core.base.expression import ScalarExpression, ExpressionData
+from pyomo.core.base.param import IndexedParam, ScalarParam, ParamData
+from pyomo.core.base.var import ScalarVar, VarData, IndexedVar
 import pyomo.core.expr as EXPR
 from pyomo.core.expr.visitor import StreamBasedExpressionVisitor, identify_variables
 from pyomo.core.base import Set, RangeSet
 from pyomo.core.base.set import SetProduct
+from pyomo.repn.util import ExitNodeDispatcher
 from pyomo.opt import WriterFactory, SolverFactory, TerminationCondition, SolverResults
 
 ### FIXME: Remove the following as soon as non-active components no
@@ -449,6 +467,7 @@ def _create_docplex_interval_var(visitor, interval_var):
     nm = interval_var.name if visitor.symbolic_solver_labels else None
     cpx_interval_var = cp.interval_var(name=nm)
     visitor.var_map[id(interval_var)] = cpx_interval_var
+    visitor.pyomo_to_docplex[interval_var] = cpx_interval_var
 
     # Figure out if it exists
     if interval_var.is_present.fixed and not interval_var.is_present.value:
@@ -491,6 +510,19 @@ def _create_docplex_interval_var(visitor, interval_var):
     return cpx_interval_var
 
 
+def _create_docplex_sequence_var(visitor, sequence_var):
+    nm = sequence_var.name if visitor.symbolic_solver_labels else None
+
+    cpx_seq_var = cp.sequence_var(
+        name=nm,
+        vars=[
+            _get_docplex_interval_var(visitor, v) for v in sequence_var.interval_vars
+        ],
+    )
+    visitor.var_map[id(sequence_var)] = cpx_seq_var
+    return cpx_seq_var
+
+
 def _get_docplex_interval_var(visitor, interval_var):
     # We might already have the interval_var and just need to retrieve it
     if id(interval_var) in visitor.var_map:
@@ -501,6 +533,25 @@ def _get_docplex_interval_var(visitor, interval_var):
     return cpx_interval_var
 
 
+def _get_docplex_sequence_var(visitor, sequence_var):
+    if id(sequence_var) in visitor.var_map:
+        cpx_seq_var = visitor.var_map[id(sequence_var)]
+    else:
+        cpx_seq_var = _create_docplex_sequence_var(visitor, sequence_var)
+        visitor.cpx.add(cpx_seq_var)
+    return cpx_seq_var
+
+
+def _before_sequence_var(visitor, child):
+    _id = id(child)
+    if _id not in visitor.var_map:
+        cpx_seq_var = _get_docplex_sequence_var(visitor, child)
+        visitor.var_map[_id] = cpx_seq_var
+        visitor.pyomo_to_docplex[child] = cpx_seq_var
+
+    return False, (_GENERAL, visitor.var_map[_id])
+
+
 def _before_interval_var(visitor, child):
     _id = id(child)
     if _id not in visitor.var_map:
@@ -564,22 +615,22 @@ def _before_interval_var_presence(visitor, child):
 
 
 def _handle_step_at_node(visitor, node):
-    return cp.step_at(node._time, node._height)
+    return False, (_GENERAL, cp.step_at(node._time, node._height))
 
 
 def _handle_step_at_start_node(visitor, node):
     cpx_var = _get_docplex_interval_var(visitor, node._time)
-    return cp.step_at_start(cpx_var, node._height)
+    return False, (_GENERAL, cp.step_at_start(cpx_var, node._height))
 
 
 def _handle_step_at_end_node(visitor, node):
     cpx_var = _get_docplex_interval_var(visitor, node._time)
-    return cp.step_at_end(cpx_var, node._height)
+    return False, (_GENERAL, cp.step_at_end(cpx_var, node._height))
 
 
 def _handle_pulse_node(visitor, node):
     cpx_var = _get_docplex_interval_var(visitor, node._interval_var)
-    return cp.pulse(cpx_var, node._height)
+    return False, (_GENERAL, cp.pulse(cpx_var, node._height))
 
 
 def _handle_negated_step_function_node(visitor, node):
@@ -590,9 +641,9 @@ def _handle_cumulative_function(visitor, node):
     expr = 0
     for arg in node.args:
         if arg.__class__ is NegatedStepFunction:
-            expr -= _handle_negated_step_function_node(visitor, arg)
+            expr -= _handle_negated_step_function_node(visitor, arg)[1][1]
         else:
-            expr += _step_function_handles[arg.__class__](visitor, arg)
+            expr += _step_function_handles[arg.__class__](visitor, arg)[1][1]
 
     return False, (_GENERAL, expr)
 
@@ -658,7 +709,7 @@ def _handle_monomial_expr(visitor, node, arg1, arg2):
     # simplifications (necessary in part for the unit tests)
     if arg2[1].__class__ in EXPR.native_types:
         return _GENERAL, arg1[1] * arg2[1]
-    elif arg1[1] == 1:
+    elif arg1[1].__class__ in EXPR.native_types and arg1[1] == 1:
         return arg2
     return (_GENERAL, cp.times(_get_int_valued_expr(arg1), _get_int_valued_expr(arg2)))
 
@@ -805,6 +856,14 @@ def _handle_at_least_node(visitor, node, *args):
     )
 
 
+def _handle_all_diff_node(visitor, node, *args):
+    return (_GENERAL, cp.all_diff(_get_int_valued_expr(arg) for arg in args))
+
+
+def _handle_count_if_node(visitor, node, *args):
+    return (_GENERAL, cp.count((_get_bool_valued_expr(arg) for arg in args), 1))
+
+
 ## CallExpression handllers
 
 
@@ -902,46 +961,91 @@ def _handle_always_in_node(visitor, node, cumul_func, lb, ub, start, end):
     )
 
 
+def _handle_no_overlap_expression_node(visitor, node, seq_var):
+    return _GENERAL, cp.no_overlap(seq_var[1])
+
+
+def _handle_first_in_sequence_expression_node(visitor, node, interval_var, seq_var):
+    return _GENERAL, cp.first(seq_var[1], interval_var[1])
+
+
+def _handle_last_in_sequence_expression_node(visitor, node, interval_var, seq_var):
+    return _GENERAL, cp.last(seq_var[1], interval_var[1])
+
+
+def _handle_before_in_sequence_expression_node(
+    visitor, node, before_var, after_var, seq_var
+):
+    return _GENERAL, cp.before(seq_var[1], before_var[1], after_var[1])
+
+
+def _handle_predecessor_to_expression_node(
+    visitor, node, before_var, after_var, seq_var
+):
+    return _GENERAL, cp.previous(seq_var[1], before_var[1], after_var[1])
+
+
+def _handle_span_expression_node(visitor, node, *args):
+    return _GENERAL, cp.span(args[0][1], [arg[1] for arg in args[1:]])
+
+
+def _handle_alternative_expression_node(visitor, node, *args):
+    return _GENERAL, cp.alternative(args[0][1], [arg[1] for arg in args[1:]])
+
+
+def _handle_synchronize_expression_node(visitor, node, *args):
+    return _GENERAL, cp.synchronize(args[0][1], [arg[1] for arg in args[1:]])
+
+
+_operator_handles = {
+    EXPR.GetItemExpression: _handle_getitem,
+    EXPR.GetAttrExpression: _handle_getattr,
+    EXPR.CallExpression: _handle_call,
+    EXPR.NegationExpression: _handle_negation_node,
+    EXPR.ProductExpression: _handle_product_node,
+    EXPR.DivisionExpression: _handle_division_node,
+    EXPR.PowExpression: _handle_pow_node,
+    EXPR.AbsExpression: _handle_abs_node,
+    EXPR.MonomialTermExpression: _handle_monomial_expr,
+    EXPR.SumExpression: _handle_sum_node,
+    EXPR.MinExpression: _handle_min_node,
+    EXPR.MaxExpression: _handle_max_node,
+    EXPR.NotExpression: _handle_not_node,
+    EXPR.EquivalenceExpression: _handle_equivalence_node,
+    EXPR.ImplicationExpression: _handle_implication_node,
+    EXPR.AndExpression: _handle_and_node,
+    EXPR.OrExpression: _handle_or_node,
+    EXPR.XorExpression: _handle_xor_node,
+    EXPR.ExactlyExpression: _handle_exactly_node,
+    EXPR.AtMostExpression: _handle_at_most_node,
+    EXPR.AtLeastExpression: _handle_at_least_node,
+    EXPR.AllDifferentExpression: _handle_all_diff_node,
+    EXPR.CountIfExpression: _handle_count_if_node,
+    EXPR.EqualityExpression: _handle_equality_node,
+    EXPR.NotEqualExpression: _handle_not_equal_node,
+    EXPR.InequalityExpression: _handle_inequality_node,
+    EXPR.RangedExpression: _handle_ranged_inequality_node,
+    BeforeExpression: _handle_before_expression_node,
+    AtExpression: _handle_at_expression_node,
+    AlwaysIn: _handle_always_in_node,
+    ExpressionData: _handle_named_expression_node,
+    ScalarExpression: _handle_named_expression_node,
+    NoOverlapExpression: _handle_no_overlap_expression_node,
+    FirstInSequenceExpression: _handle_first_in_sequence_expression_node,
+    LastInSequenceExpression: _handle_last_in_sequence_expression_node,
+    BeforeInSequenceExpression: _handle_before_in_sequence_expression_node,
+    PredecessorToExpression: _handle_predecessor_to_expression_node,
+    SpanExpression: _handle_span_expression_node,
+    AlternativeExpression: _handle_alternative_expression_node,
+    SynchronizeExpression: _handle_synchronize_expression_node,
+}
+
+
 class LogicalToDoCplex(StreamBasedExpressionVisitor):
-    _operator_handles = {
-        EXPR.GetItemExpression: _handle_getitem,
-        EXPR.Structural_GetItemExpression: _handle_getitem,
-        EXPR.Numeric_GetItemExpression: _handle_getitem,
-        EXPR.Boolean_GetItemExpression: _handle_getitem,
-        EXPR.GetAttrExpression: _handle_getattr,
-        EXPR.Structural_GetAttrExpression: _handle_getattr,
-        EXPR.Numeric_GetAttrExpression: _handle_getattr,
-        EXPR.Boolean_GetAttrExpression: _handle_getattr,
-        EXPR.CallExpression: _handle_call,
-        EXPR.NegationExpression: _handle_negation_node,
-        EXPR.ProductExpression: _handle_product_node,
-        EXPR.DivisionExpression: _handle_division_node,
-        EXPR.PowExpression: _handle_pow_node,
-        EXPR.AbsExpression: _handle_abs_node,
-        EXPR.MonomialTermExpression: _handle_monomial_expr,
-        EXPR.SumExpression: _handle_sum_node,
-        EXPR.LinearExpression: _handle_sum_node,
-        EXPR.MinExpression: _handle_min_node,
-        EXPR.MaxExpression: _handle_max_node,
-        EXPR.NotExpression: _handle_not_node,
-        EXPR.EquivalenceExpression: _handle_equivalence_node,
-        EXPR.ImplicationExpression: _handle_implication_node,
-        EXPR.AndExpression: _handle_and_node,
-        EXPR.OrExpression: _handle_or_node,
-        EXPR.XorExpression: _handle_xor_node,
-        EXPR.ExactlyExpression: _handle_exactly_node,
-        EXPR.AtMostExpression: _handle_at_most_node,
-        EXPR.AtLeastExpression: _handle_at_least_node,
-        EXPR.EqualityExpression: _handle_equality_node,
-        EXPR.NotEqualExpression: _handle_not_equal_node,
-        EXPR.InequalityExpression: _handle_inequality_node,
-        EXPR.RangedExpression: _handle_ranged_inequality_node,
-        BeforeExpression: _handle_before_expression_node,
-        AtExpression: _handle_at_expression_node,
-        AlwaysIn: _handle_always_in_node,
-        _GeneralExpressionData: _handle_named_expression_node,
-        ScalarExpression: _handle_named_expression_node,
-    }
+    exit_node_dispatcher = ExitNodeDispatcher(_operator_handles)
+    # NOTE: Because of indirection, we can encounter indexed Params and Vars in
+    # expressions
+
     _var_handles = {
         IntervalVarStartTime: _before_interval_var_start_time,
         IntervalVarEndTime: _before_interval_var_end_time,
@@ -950,16 +1054,19 @@ class LogicalToDoCplex(StreamBasedExpressionVisitor):
         ScalarIntervalVar: _before_interval_var,
         IntervalVarData: _before_interval_var,
         IndexedIntervalVar: _before_indexed_interval_var,
+        ScalarSequenceVar: _before_sequence_var,
+        SequenceVarData: _before_sequence_var,
         ScalarVar: _before_var,
-        _GeneralVarData: _before_var,
+        VarData: _before_var,
         IndexedVar: _before_indexed_var,
         ScalarBooleanVar: _before_boolean_var,
-        _GeneralBooleanVarData: _before_boolean_var,
+        BooleanVarData: _before_boolean_var,
         IndexedBooleanVar: _before_indexed_boolean_var,
-        _GeneralExpressionData: _before_named_expression,
+        ExpressionData: _before_named_expression,
         ScalarExpression: _before_named_expression,
-        IndexedParam: _before_indexed_param,  # Because of indirection
+        IndexedParam: _before_indexed_param,
         ScalarParam: _before_param,
+        ParamData: _before_param,
     }
 
     def __init__(self, cpx_model, symbolic_solver_labels=False):
@@ -993,7 +1100,7 @@ def beforeChild(self, node, child, child_idx):
         return True, None
 
     def exitNode(self, node, data):
-        return self._operator_handles[node.__class__](self, node, *data)
+        return self.exit_node_dispatcher[node.__class__](self, node, *data)
 
     finalizeResult = None
 
@@ -1005,6 +1112,9 @@ def collect_valid_components(model, active=True, sort=None, valid=set(), targets
     unrecognized = {}
     components = {k: [] for k in targets}
     for obj in model.component_data_objects(active=True, descend_into=True, sort=sort):
+        # HACK around #3045
+        if not hasattr(obj, 'ctype'):
+            continue
         ctype = obj.ctype
         if ctype in components:
             components[ctype].append(obj)
@@ -1055,7 +1165,13 @@ def write(self, model, **options):
                 RangeSet,
                 Port,
             },
-            targets={Objective, Constraint, LogicalConstraint, IntervalVar},
+            targets={
+                Objective,
+                Constraint,
+                LogicalConstraint,
+                IntervalVar,
+                SequenceVar,
+            },
         )
         if unknown:
             raise ValueError(
@@ -1284,6 +1400,10 @@ def solve(self, model, **kwds):
                     )
                 else:
                     sol = sol.get_value()
+                if py_var.ctype is SequenceVar:
+                    # They don't actually have values--the IntervalVars will get
+                    # set.
+                    continue
                 if py_var.ctype is IntervalVar:
                     if len(sol) == 0:
                         # The interval_var is absent
diff --git a/pyomo/contrib/cp/scheduling_expr/__init__.py b/pyomo/contrib/cp/scheduling_expr/__init__.py
index 8b137891791..a4a626013c4 100644
--- a/pyomo/contrib/cp/scheduling_expr/__init__.py
+++ b/pyomo/contrib/cp/scheduling_expr/__init__.py
@@ -1 +1,10 @@
-
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/cp/scheduling_expr/precedence_expressions.py b/pyomo/contrib/cp/scheduling_expr/precedence_expressions.py
index 5340583a216..675d9efb0a0 100644
--- a/pyomo/contrib/cp/scheduling_expr/precedence_expressions.py
+++ b/pyomo/contrib/cp/scheduling_expr/precedence_expressions.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -21,13 +21,13 @@ def delay(self):
         return self._args_[2]
 
     def _to_string_impl(self, values, relation):
-        delay = int(values[2])
-        if delay == 0:
+        delay = values[2]
+        if delay == '0':
             first = values[0]
-        elif delay > 0:
-            first = "%s + %s" % (values[0], delay)
+        elif delay[0] in '-+':
+            first = "%s %s %s" % (values[0], delay[0], delay[1:])
         else:
-            first = "%s - %s" % (values[0], abs(delay))
+            first = "%s + %s" % (values[0], delay)
         return "%s %s %s" % (first, relation, values[1])
 
 
diff --git a/pyomo/contrib/cp/scheduling_expr/scheduling_logic.py b/pyomo/contrib/cp/scheduling_expr/scheduling_logic.py
new file mode 100644
index 00000000000..e5695b57c5c
--- /dev/null
+++ b/pyomo/contrib/cp/scheduling_expr/scheduling_logic.py
@@ -0,0 +1,72 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+
+from pyomo.core.expr.logical_expr import NaryBooleanExpression, _flattened
+
+
+class SpanExpression(NaryBooleanExpression):
+    """
+    Expression over IntervalVars representing that the first arg spans all the
+    following args in the schedule. The first arg is absent if and only if all
+    the others are absent.
+
+    args:
+        args (tuple): Child nodes, of type IntervalVar
+    """
+
+    def _to_string(self, values, verbose, smap):
+        return "%s.spans(%s)" % (values[0], ", ".join(values[1:]))
+
+
+class AlternativeExpression(NaryBooleanExpression):
+    """
+    Expression over IntervalVars representing that if the first arg is present,
+    then exactly one of the following args must be present. The first arg is
+    absent if and only if all the others are absent.
+    """
+
+    # [ESJ 4/4/24]: docplex takes an optional 'cardinality' argument with this
+    # too--it generalized to "exactly n" of the intervals have to exist,
+    # basically. It would be nice to include this eventually, but this is
+    # probably fine for now.
+
+    def _to_string(self, values, verbose, smap):
+        return "alternative(%s, [%s])" % (values[0], ", ".join(values[1:]))
+
+
+class SynchronizeExpression(NaryBooleanExpression):
+    """
+    Expression over IntervalVars synchronizing the first argument with all of the
+    following arguments. That is, if the first argument is present, the remaining
+    arguments start and end at the same time as it.
+    """
+
+    def _to_string(self, values, verbose, smap):
+        return "synchronize(%s, [%s])" % (values[0], ", ".join(values[1:]))
+
+
+def spans(*args):
+    """Creates a new SpanExpression"""
+
+    return SpanExpression(list(_flattened(args)))
+
+
+def alternative(*args):
+    """Creates a new AlternativeExpression"""
+
+    return AlternativeExpression(list(_flattened(args)))
+
+
+def synchronize(*args):
+    """Creates a new SynchronizeExpression"""
+
+    return SynchronizeExpression(list(_flattened(args)))
diff --git a/pyomo/contrib/cp/scheduling_expr/sequence_expressions.py b/pyomo/contrib/cp/scheduling_expr/sequence_expressions.py
new file mode 100644
index 00000000000..3ba799074de
--- /dev/null
+++ b/pyomo/contrib/cp/scheduling_expr/sequence_expressions.py
@@ -0,0 +1,173 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+from pyomo.core.expr.logical_expr import BooleanExpression
+
+
+class NoOverlapExpression(BooleanExpression):
+    """
+    Expression representing that none of the IntervalVars in a SequenceVar overlap
+    (if they are scheduled)
+
+    args:
+        args (tuple): Child node of type SequenceVar
+    """
+
+    def nargs(self):
+        return 1
+
+    def _to_string(self, values, verbose, smap):
+        return "no_overlap(%s)" % values[0]
+
+
+class FirstInSequenceExpression(BooleanExpression):
+    """
+    Expression representing that the specified IntervalVar is the first in the
+    sequence specified by SequenceVar (if it is scheduled)
+
+    args:
+        args (tuple): Child nodes, the first of type IntervalVar, the second of type
+                      SequenceVar
+    """
+
+    def nargs(self):
+        return 2
+
+    def _to_string(self, values, verbose, smap):
+        return "first_in(%s, %s)" % (values[0], values[1])
+
+
+class LastInSequenceExpression(BooleanExpression):
+    """
+    Expression representing that the specified IntervalVar is the last in the
+    sequence specified by SequenceVar (if it is scheduled)
+
+    args:
+        args (tuple): Child nodes, the first of type IntervalVar, the second of type
+                      SequenceVar
+    """
+
+    def nargs(self):
+        return 2
+
+    def _to_string(self, values, verbose, smap):
+        return "last_in(%s, %s)" % (values[0], values[1])
+
+
+class BeforeInSequenceExpression(BooleanExpression):
+    """
+    Expression representing that one IntervalVar occurs before another in the
+    sequence specified by the given SequenceVar (if both are scheduled)
+
+    args:
+        args (tuple): Child nodes, the IntervalVar that must be before, the
+                      IntervalVar that must be after, and the SequenceVar
+    """
+
+    def nargs(self):
+        return 3
+
+    def _to_string(self, values, verbose, smap):
+        return "before_in(%s, %s, %s)" % (values[0], values[1], values[2])
+
+
+class PredecessorToExpression(BooleanExpression):
+    """
+    Expression representing that one IntervalVar is a direct predecessor to another
+    in the sequence specified by the given SequenceVar (if both are scheduled)
+
+    args:
+        args (tuple): Child nodes, the predecessor IntervalVar, the successor
+                      IntervalVar, and the SequenceVar
+    """
+
+    def nargs(self):
+        return 3
+
+    def _to_string(self, values, verbose, smap):
+        return "predecessor_to(%s, %s, %s)" % (values[0], values[1], values[2])
+
+
+def no_overlap(sequence_var):
+    """
+    Creates a new NoOverlapExpression
+
+    Requires that none of the scheduled intervals in the SequenceVar overlap each other
+
+    args:
+        sequence_var: A SequenceVar
+    """
+    return NoOverlapExpression((sequence_var,))
+
+
+def first_in_sequence(interval_var, sequence_var):
+    """
+    Creates a new FirstInSequenceExpression
+
+    Requires that 'interval_var' be the first in the sequence specified by
+    'sequence_var' if it is scheduled
+
+    args:
+        interval_var (IntervalVar): The activity that should be scheduled first
+            if it is scheduled at all
+        sequence_var (SequenceVar): The sequence of activities
+    """
+    return FirstInSequenceExpression((interval_var, sequence_var))
+
+
+def last_in_sequence(interval_var, sequence_var):
+    """
+    Creates a new LastInSequenceExpression
+
+    Requires that 'interval_var' be the last in the sequence specified by
+    'sequence_var' if it is scheduled
+
+    args:
+        interval_var (IntervalVar): The activity that should be scheduled last
+            if it is scheduled at all
+        sequence_var (SequenceVar): The sequence of activities
+    """
+
+    return LastInSequenceExpression((interval_var, sequence_var))
+
+
+def before_in_sequence(before_var, after_var, sequence_var):
+    """
+    Creates a new BeforeInSequenceExpression
+
+    Requires that 'before_var' be scheduled to start before 'after_var' in the
+    sequence specified bv 'sequence_var', if both are scheduled
+
+    args:
+        before_var (IntervalVar): The activity that should be scheduled earlier in
+            the sequence
+        after_var (IntervalVar): The activity that should be scheduled later in the
+            sequence
+        sequence_var (SequenceVar): The sequence of activities
+    """
+    return BeforeInSequenceExpression((before_var, after_var, sequence_var))
+
+
+def predecessor_to(before_var, after_var, sequence_var):
+    """
+    Creates a new PredecessorToExpression
+
+    Requires that 'before_var' be a direct predecessor to 'after_var' in the
+    sequence specified by 'sequence_var', if both are scheduled
+
+    args:
+        before_var (IntervalVar): The activity that should be scheduled as the
+            predecessor
+        after_var (IntervalVar): The activity that should be scheduled as the
+            successor
+        sequence_var (SequenceVar): The sequence of activities
+    """
+    return PredecessorToExpression((before_var, after_var, sequence_var))
diff --git a/pyomo/contrib/cp/scheduling_expr/step_function_expressions.py b/pyomo/contrib/cp/scheduling_expr/step_function_expressions.py
index b4f8fbb4977..129dff66b48 100644
--- a/pyomo/contrib/cp/scheduling_expr/step_function_expressions.py
+++ b/pyomo/contrib/cp/scheduling_expr/step_function_expressions.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -15,7 +15,6 @@
     IntervalVarStartTime,
     IntervalVarEndTime,
 )
-from pyomo.core.base.component import Component
 from pyomo.core.expr.base import ExpressionBase
 from pyomo.core.expr.logical_expr import BooleanExpression
 
diff --git a/pyomo/contrib/cp/sequence_var.py b/pyomo/contrib/cp/sequence_var.py
new file mode 100644
index 00000000000..cb42f445dc3
--- /dev/null
+++ b/pyomo/contrib/cp/sequence_var.py
@@ -0,0 +1,151 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import logging
+
+from pyomo.common.log import is_debug_set
+from pyomo.common.modeling import NOTSET
+from pyomo.contrib.cp import IntervalVar
+from pyomo.core import ModelComponentFactory
+from pyomo.core.base.component import ActiveComponentData
+from pyomo.core.base.global_set import UnindexedComponent_index
+from pyomo.core.base.indexed_component import ActiveIndexedComponent
+from pyomo.core.base.initializer import Initializer
+
+import sys
+from weakref import ref as weakref_ref
+
+logger = logging.getLogger(__name__)
+
+
+class SequenceVarData(ActiveComponentData):
+    """This class defines the abstract interface for a single sequence variable."""
+
+    __slots__ = ('interval_vars',)
+
+    def __init__(self, component=None):
+        # in-lining ActiveComponentData and ComponentData constructors, as is
+        # traditional:
+        self._component = weakref_ref(component) if (component is not None) else None
+        self._index = NOTSET
+        self._active = True
+
+        # This thing is really just an ordered set of interval vars that we can
+        # write constraints over.
+        self.interval_vars = []
+
+    def set_value(self, expr):
+        # We'll demand expr be a list for now--it needs to be ordered so this
+        # doesn't seem like too much to ask
+        if not hasattr(expr, '__iter__'):
+            raise ValueError(
+                "'expr' for SequenceVar must be a list of IntervalVars. "
+                "Encountered type '%s' constructing '%s'" % (type(expr), self.name)
+            )
+        for v in expr:
+            if not hasattr(v, 'ctype') or v.ctype is not IntervalVar:
+                raise ValueError(
+                    "The SequenceVar 'expr' argument must be a list of "
+                    "IntervalVars. The 'expr' for SequenceVar '%s' included "
+                    "an object of type '%s'" % (self.name, type(v))
+                )
+            self.interval_vars.append(v)
+
+
+@ModelComponentFactory.register("Sequences of IntervalVars")
+class SequenceVar(ActiveIndexedComponent):
+    _ComponentDataClass = SequenceVarData
+
+    def __new__(cls, *args, **kwds):
+        if cls != SequenceVar:
+            return super(SequenceVar, cls).__new__(cls)
+        if args == ():
+            return ScalarSequenceVar.__new__(ScalarSequenceVar)
+        else:
+            return IndexedSequenceVar.__new__(IndexedSequenceVar)
+
+    def __init__(self, *args, **kwargs):
+        self._init_rule = Initializer(kwargs.pop('rule', None))
+        self._init_expr = kwargs.pop('expr', None)
+        kwargs.setdefault('ctype', SequenceVar)
+        super(SequenceVar, self).__init__(*args, **kwargs)
+
+        if self._init_expr is not None and self._init_rule is not None:
+            raise ValueError(
+                "Cannot specify both rule= and expr= for SequenceVar %s" % (self.name,)
+            )
+
+    def _getitem_when_not_present(self, index):
+        if index is None and not self.is_indexed():
+            obj = self._data[index] = self
+        else:
+            obj = self._data[index] = self._ComponentDataClass(component=self)
+        parent = self.parent_block()
+        obj._index = index
+
+        if self._init_rule is not None:
+            obj.set_value(self._init_rule(parent, index))
+        if self._init_expr is not None:
+            obj.set_value(self._init_expr)
+
+        return obj
+
+    def construct(self, data=None):
+        """
+        Construct the SequenceVarData objects for this SequenceVar
+        """
+        if self._constructed:
+            return
+        self._constructed = True
+
+        if is_debug_set(logger):
+            logger.debug("Constructing SequenceVar %s" % self.name)
+
+        # Initialize index in case we hit the exception below
+        index = None
+        try:
+            if not self.is_indexed():
+                self._getitem_when_not_present(None)
+            if self._init_rule is not None:
+                for index in self.index_set():
+                    self._getitem_when_not_present(index)
+        except Exception:
+            err = sys.exc_info()[1]
+            logger.error(
+                "Rule failed when initializing sequence variable for "
+                "SequenceVar %s with index %s:\n%s: %s"
+                % (self.name, str(index), type(err).__name__, err)
+            )
+            raise
+
+    def _pprint(self):
+        """Print component information."""
+        headers = [
+            ("Size", len(self)),
+            ("Index", self._index_set if self.is_indexed() else None),
+        ]
+        return (
+            headers,
+            self._data.items(),
+            ("IntervalVars",),
+            lambda k, v: ['[' + ', '.join(iv.name for iv in v.interval_vars) + ']'],
+        )
+
+
+class ScalarSequenceVar(SequenceVarData, SequenceVar):
+    def __init__(self, *args, **kwds):
+        SequenceVarData.__init__(self, component=self)
+        SequenceVar.__init__(self, *args, **kwds)
+        self._index = UnindexedComponent_index
+
+
+class IndexedSequenceVar(SequenceVar):
+    pass
diff --git a/pyomo/contrib/cp/tests/__init__.py b/pyomo/contrib/cp/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/cp/tests/__init__.py
+++ b/pyomo/contrib/cp/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/cp/tests/test_docplex_walker.py b/pyomo/contrib/cp/tests/test_docplex_walker.py
index 97bc538c827..f7abb3d2b3c 100644
--- a/pyomo/contrib/cp/tests/test_docplex_walker.py
+++ b/pyomo/contrib/cp/tests/test_docplex_walker.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -11,17 +11,28 @@
 
 import pyomo.common.unittest as unittest
 
-from pyomo.contrib.cp import IntervalVar
-from pyomo.contrib.cp.scheduling_expr.step_function_expressions import (
-    AlwaysIn,
-    Step,
-    Pulse,
+from pyomo.contrib.cp import (
+    IntervalVar,
+    SequenceVar,
+    no_overlap,
+    first_in_sequence,
+    last_in_sequence,
+    alternative,
+    synchronize,
 )
+from pyomo.contrib.cp.scheduling_expr.step_function_expressions import Step, Pulse
 from pyomo.contrib.cp.repn.docplex_writer import docplex_available, LogicalToDoCplex
 
 from pyomo.core.base.range import NumericRange
 from pyomo.core.expr.numeric_expr import MinExpression, MaxExpression
-from pyomo.core.expr.logical_expr import equivalent, exactly, atleast, atmost
+from pyomo.core.expr.logical_expr import (
+    equivalent,
+    exactly,
+    atleast,
+    atmost,
+    all_different,
+    count_if,
+)
 from pyomo.core.expr.relational_expr import NotEqualExpression
 
 from pyomo.environ import (
@@ -39,8 +50,6 @@
     Integers,
     inequality,
     Expression,
-    Reals,
-    Set,
     Param,
 )
 
@@ -91,6 +100,10 @@ def test_write_addition(self):
             expr[1].equals(cpx_x + cp.start_of(cpx_i) + cp.length_of(cpx_i2))
         )
 
+        self.assertIs(visitor.pyomo_to_docplex[m.x], cpx_x)
+        self.assertIs(visitor.pyomo_to_docplex[m.i], cpx_i)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[2]], cpx_i2)
+
     def test_write_subtraction(self):
         m = self.get_model()
         m.a.domain = Binary
@@ -106,6 +119,9 @@ def test_write_subtraction(self):
 
         self.assertTrue(expr[1].equals(x + (-1 * a1)))
 
+        self.assertIs(visitor.pyomo_to_docplex[m.x], x)
+        self.assertIs(visitor.pyomo_to_docplex[m.a[1]], a1)
+
     def test_write_product(self):
         m = self.get_model()
         m.a.domain = PositiveIntegers
@@ -121,6 +137,9 @@ def test_write_product(self):
 
         self.assertTrue(expr[1].equals(x * (a1 + 1)))
 
+        self.assertIs(visitor.pyomo_to_docplex[m.x], x)
+        self.assertIs(visitor.pyomo_to_docplex[m.a[1]], a1)
+
     def test_write_floating_point_division(self):
         m = self.get_model()
         m.a.domain = NonNegativeIntegers
@@ -136,6 +155,9 @@ def test_write_floating_point_division(self):
 
         self.assertTrue(expr[1].equals(x / (a1 + 1)))
 
+        self.assertIs(visitor.pyomo_to_docplex[m.x], x)
+        self.assertIs(visitor.pyomo_to_docplex[m.a[1]], a1)
+
     def test_write_power_expression(self):
         m = self.get_model()
         m.c = Constraint(expr=m.x**2 <= 3)
@@ -147,6 +169,8 @@ def test_write_power_expression(self):
         # .equals checks the equality of two expressions in docplex.
         self.assertTrue(expr[1].equals(cpx_x**2))
 
+        self.assertIs(visitor.pyomo_to_docplex[m.x], cpx_x)
+
     def test_write_absolute_value_expression(self):
         m = self.get_model()
         m.a.domain = NegativeIntegers
@@ -160,6 +184,8 @@ def test_write_absolute_value_expression(self):
 
         self.assertTrue(expr[1].equals(cp.abs(a1) + 1))
 
+        self.assertIs(visitor.pyomo_to_docplex[m.a[1]], a1)
+
     def test_write_min_expression(self):
         m = self.get_model()
         m.a.domain = NonPositiveIntegers
@@ -171,6 +197,7 @@ def test_write_min_expression(self):
         for i in m.I:
             self.assertIn(id(m.a[i]), visitor.var_map)
             a[i] = visitor.var_map[id(m.a[i])]
+            self.assertIs(visitor.pyomo_to_docplex[m.a[i]], a[i])
 
         self.assertTrue(expr[1].equals(cp.min(a[i] for i in m.I)))
 
@@ -185,6 +212,7 @@ def test_write_max_expression(self):
         for i in m.I:
             self.assertIn(id(m.a[i]), visitor.var_map)
             a[i] = visitor.var_map[id(m.a[i])]
+            self.assertIs(visitor.pyomo_to_docplex[m.a[i]], a[i])
 
         self.assertTrue(expr[1].equals(cp.max(a[i] for i in m.I)))
 
@@ -202,6 +230,35 @@ def test_expression_with_mutable_param(self):
 
         self.assertTrue(expr[1].equals(4 * x))
 
+    def test_monomial_expressions(self):
+        m = ConcreteModel()
+        m.x = Var(domain=Integers, bounds=(1, 4))
+        m.p = Param(initialize=4, mutable=True)
+
+        visitor = self.get_visitor()
+
+        const_expr = 3 * m.x
+        nested_expr = (1 / m.p) * m.x
+        pow_expr = (m.p ** (0.5)) * m.x
+
+        e = m.x * 4
+        expr = visitor.walk_expression((e, e, 0))
+        self.assertIn(id(m.x), visitor.var_map)
+        x = visitor.var_map[id(m.x)]
+        self.assertTrue(expr[1].equals(4 * x))
+
+        e = 1.0 * m.x
+        expr = visitor.walk_expression((e, e, 0))
+        self.assertTrue(expr[1].equals(x))
+
+        e = (1 / m.p) * m.x
+        expr = visitor.walk_expression((e, e, 0))
+        self.assertTrue(expr[1].equals(cp.float_div(1, 4) * x))
+
+        e = (m.p ** (0.5)) * m.x
+        expr = visitor.walk_expression((e, e, 0))
+        self.assertTrue(expr[1].equals(cp.power(4, 0.5) * x))
+
 
 @unittest.skipIf(not docplex_available, "docplex is not available")
 class TestCPExpressionWalker_LogicalExpressions(CommonTest):
@@ -219,6 +276,14 @@ def test_write_logical_and(self):
 
         self.assertTrue(expr[1].equals(cp.logical_and(b, b2b)))
 
+        # ESJ: This is ludicrous, but I don't know how to get the args of a CP
+        # expression, so testing that we were correct in the pyomo to docplex
+        # map by checking that we can build an expression that is the same as b
+        # (because b is actually "b == 1" since docplex doesn't believe in
+        # Booleans)
+        self.assertTrue(b.equals(visitor.pyomo_to_docplex[m.b] == 1))
+        self.assertTrue(b2b.equals(visitor.pyomo_to_docplex[m.b2['b']] == 1))
+
     def test_write_logical_or(self):
         m = self.get_model()
         m.c = LogicalConstraint(expr=m.b.lor(m.i.is_present))
@@ -232,6 +297,9 @@ def test_write_logical_or(self):
 
         self.assertTrue(expr[1].equals(cp.logical_or(b, cp.presence_of(i))))
 
+        self.assertTrue(b.equals(visitor.pyomo_to_docplex[m.b] == 1))
+        self.assertIs(visitor.pyomo_to_docplex[m.i], i)
+
     def test_write_xor(self):
         m = self.get_model()
         m.c = LogicalConstraint(expr=m.b.xor(m.i2[2].start_time >= 5))
@@ -249,6 +317,9 @@ def test_write_xor(self):
             expr[1].equals(cp.count([b, cp.less_or_equal(5, cp.start_of(i22))], 1) == 1)
         )
 
+        self.assertTrue(b.equals(visitor.pyomo_to_docplex[m.b] == 1))
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[2]], i22)
+
     def test_write_logical_not(self):
         m = self.get_model()
         m.c = LogicalConstraint(expr=~m.b2['a'])
@@ -260,6 +331,8 @@ def test_write_logical_not(self):
 
         self.assertTrue(expr[1].equals(cp.logical_not(b2a)))
 
+        self.assertTrue(b2a.equals(visitor.pyomo_to_docplex[m.b2['a']] == 1))
+
     def test_equivalence(self):
         m = self.get_model()
         m.c = LogicalConstraint(expr=equivalent(~m.b2['a'], m.b))
@@ -273,18 +346,8 @@ def test_equivalence(self):
 
         self.assertTrue(expr[1].equals(cp.equal(cp.logical_not(b2a), b)))
 
-    def test_implication(self):
-        m = self.get_model()
-        m.c = LogicalConstraint(expr=m.b2['a'].implies(~m.b))
-        visitor = self.get_visitor()
-        expr = visitor.walk_expression((m.c.expr, m.c, 0))
-
-        self.assertIn(id(m.b), visitor.var_map)
-        self.assertIn(id(m.b2['a']), visitor.var_map)
-        b = visitor.var_map[id(m.b)]
-        b2a = visitor.var_map[id(m.b2['a'])]
-
-        self.assertTrue(expr[1].equals(cp.if_then(b2a, cp.logical_not(b))))
+        self.assertTrue(b.equals(visitor.pyomo_to_docplex[m.b] == 1))
+        self.assertTrue(b2a.equals(visitor.pyomo_to_docplex[m.b2['a']] == 1))
 
     def test_equality(self):
         m = self.get_model()
@@ -301,6 +364,9 @@ def test_equality(self):
 
         self.assertTrue(expr[1].equals(cp.if_then(b, cp.equal(a3, 4))))
 
+        self.assertTrue(b.equals(visitor.pyomo_to_docplex[m.b] == 1))
+        self.assertIs(visitor.pyomo_to_docplex[m.a[3]], a3)
+
     def test_inequality(self):
         m = self.get_model()
         m.a.domain = Integers
@@ -318,6 +384,10 @@ def test_inequality(self):
 
         self.assertTrue(expr[1].equals(cp.if_then(b, cp.less_or_equal(a4, a3))))
 
+        self.assertTrue(b.equals(visitor.pyomo_to_docplex[m.b] == 1))
+        self.assertIs(visitor.pyomo_to_docplex[m.a[3]], a3)
+        self.assertIs(visitor.pyomo_to_docplex[m.a[4]], a4)
+
     def test_ranged_inequality(self):
         m = self.get_model()
         m.a.domain = Integers
@@ -348,6 +418,10 @@ def test_not_equal(self):
 
         self.assertTrue(expr[1].equals(cp.if_then(b, a3 != a4)))
 
+        self.assertTrue(b.equals(visitor.pyomo_to_docplex[m.b] == 1))
+        self.assertIs(visitor.pyomo_to_docplex[m.a[3]], a3)
+        self.assertIs(visitor.pyomo_to_docplex[m.a[4]], a4)
+
     def test_exactly_expression(self):
         m = self.get_model()
         m.a.domain = Integers
@@ -360,6 +434,7 @@ def test_exactly_expression(self):
         for i in m.I:
             self.assertIn(id(m.a[i]), visitor.var_map)
             a[i] = visitor.var_map[id(m.a[i])]
+            self.assertIs(visitor.pyomo_to_docplex[m.a[i]], a[i])
 
         self.assertTrue(
             expr[1].equals(cp.equal(cp.count([a[i] == 4 for i in m.I], 1), 3))
@@ -377,6 +452,7 @@ def test_atleast_expression(self):
         for i in m.I:
             self.assertIn(id(m.a[i]), visitor.var_map)
             a[i] = visitor.var_map[id(m.a[i])]
+            self.assertIs(visitor.pyomo_to_docplex[m.a[i]], a[i])
 
         self.assertTrue(
             expr[1].equals(
@@ -396,11 +472,46 @@ def test_atmost_expression(self):
         for i in m.I:
             self.assertIn(id(m.a[i]), visitor.var_map)
             a[i] = visitor.var_map[id(m.a[i])]
+            self.assertIs(visitor.pyomo_to_docplex[m.a[i]], a[i])
 
         self.assertTrue(
             expr[1].equals(cp.less_or_equal(cp.count([a[i] == 4 for i in m.I], 1), 3))
         )
 
+    def test_all_diff_expression(self):
+        m = self.get_model()
+        m.a.domain = Integers
+        m.a.bounds = (11, 20)
+        m.c = LogicalConstraint(expr=all_different(m.a))
+
+        visitor = self.get_visitor()
+        expr = visitor.walk_expression((m.c.body, m.c, 0))
+
+        a = {}
+        for i in m.I:
+            self.assertIn(id(m.a[i]), visitor.var_map)
+            a[i] = visitor.var_map[id(m.a[i])]
+            self.assertIs(visitor.pyomo_to_docplex[m.a[i]], a[i])
+
+        self.assertTrue(expr[1].equals(cp.all_diff(a[i] for i in m.I)))
+
+    def test_count_if_expression(self):
+        m = self.get_model()
+        m.a.domain = Integers
+        m.a.bounds = (11, 20)
+        m.c = Constraint(expr=count_if(m.a[i] == i for i in m.I) == 5)
+
+        visitor = self.get_visitor()
+        expr = visitor.walk_expression((m.c.expr, m.c, 0))
+
+        a = {}
+        for i in m.I:
+            self.assertIn(id(m.a[i]), visitor.var_map)
+            a[i] = visitor.var_map[id(m.a[i])]
+            self.assertIs(visitor.pyomo_to_docplex[m.a[i]], a[i])
+
+        self.assertTrue(expr[1].equals(cp.count((a[i] == i for i in m.I), 1) == 5))
+
     def test_interval_var_is_present(self):
         m = self.get_model()
         m.a.domain = Integers
@@ -416,6 +527,9 @@ def test_interval_var_is_present(self):
 
         self.assertTrue(expr[1].equals(cp.if_then(cp.presence_of(i), a1 == 5)))
 
+        self.assertIs(visitor.pyomo_to_docplex[m.a[1]], a1)
+        self.assertIs(visitor.pyomo_to_docplex[m.i], i)
+
     def test_interval_var_is_present_indirection(self):
         m = self.get_model()
         m.a.domain = Integers
@@ -449,6 +563,11 @@ def test_interval_var_is_present_indirection(self):
             )
         )
 
+        self.assertIs(visitor.pyomo_to_docplex[m.a[1]], a1)
+        self.assertIs(visitor.pyomo_to_docplex[m.y], y)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[1]], i21)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[2]], i22)
+
     def test_is_present_indirection_and_length(self):
         m = self.get_model()
         m.y = Var(domain=Integers, bounds=[1, 2])
@@ -483,6 +602,10 @@ def test_is_present_indirection_and_length(self):
             )
         )
 
+        self.assertIs(visitor.pyomo_to_docplex[m.y], y)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[1]], i21)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[2]], i22)
+
     def test_handle_getattr_lor(self):
         m = self.get_model()
         m.y = Var(domain=Integers, bounds=(1, 2))
@@ -514,6 +637,11 @@ def test_handle_getattr_lor(self):
             )
         )
 
+        self.assertIs(visitor.pyomo_to_docplex[m.y], y)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[1]], i21)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[2]], i22)
+        self.assertTrue(b.equals(visitor.pyomo_to_docplex[m.b] == 1))
+
     def test_handle_getattr_xor(self):
         m = self.get_model()
         m.y = Var(domain=Integers, bounds=(1, 2))
@@ -552,6 +680,11 @@ def test_handle_getattr_xor(self):
             )
         )
 
+        self.assertIs(visitor.pyomo_to_docplex[m.y], y)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[1]], i21)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[2]], i22)
+        self.assertTrue(b.equals(visitor.pyomo_to_docplex[m.b] == 1))
+
     def test_handle_getattr_equivalent_to(self):
         m = self.get_model()
         m.y = Var(domain=Integers, bounds=(1, 2))
@@ -583,6 +716,11 @@ def test_handle_getattr_equivalent_to(self):
             )
         )
 
+        self.assertIs(visitor.pyomo_to_docplex[m.y], y)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[1]], i21)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[2]], i22)
+        self.assertTrue(b.equals(visitor.pyomo_to_docplex[m.b] == 1))
+
     def test_logical_or_on_indirection(self):
         m = ConcreteModel()
         m.b = BooleanVar([2, 3, 4, 5])
@@ -612,6 +750,11 @@ def test_logical_or_on_indirection(self):
             )
         )
 
+        self.assertIs(visitor.pyomo_to_docplex[m.x], x)
+        self.assertTrue(b3.equals(visitor.pyomo_to_docplex[m.b[3]] == 1))
+        self.assertTrue(b4.equals(visitor.pyomo_to_docplex[m.b[4]] == 1))
+        self.assertTrue(b5.equals(visitor.pyomo_to_docplex[m.b[5]] == 1))
+
     def test_logical_xor_on_indirection(self):
         m = ConcreteModel()
         m.b = BooleanVar([2, 3, 4, 5])
@@ -646,6 +789,10 @@ def test_logical_xor_on_indirection(self):
             )
         )
 
+        self.assertIs(visitor.pyomo_to_docplex[m.x], x)
+        self.assertTrue(b3.equals(visitor.pyomo_to_docplex[m.b[3]] == 1))
+        self.assertTrue(b5.equals(visitor.pyomo_to_docplex[m.b[5]] == 1))
+
     def test_using_precedence_expr_as_boolean_expr(self):
         m = self.get_model()
         e = m.b.implies(m.i2[2].start_time.before(m.i2[1].start_time))
@@ -665,6 +812,10 @@ def test_using_precedence_expr_as_boolean_expr(self):
             expr[1].equals(cp.if_then(b, cp.start_of(i22) + 0 <= cp.start_of(i21)))
         )
 
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[1]], i21)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[2]], i22)
+        self.assertTrue(b.equals(visitor.pyomo_to_docplex[m.b] == 1))
+
     def test_using_precedence_expr_as_boolean_expr_positive_delay(self):
         m = self.get_model()
         e = m.b.implies(m.i2[2].start_time.before(m.i2[1].start_time, delay=4))
@@ -684,6 +835,10 @@ def test_using_precedence_expr_as_boolean_expr_positive_delay(self):
             expr[1].equals(cp.if_then(b, cp.start_of(i22) + 4 <= cp.start_of(i21)))
         )
 
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[1]], i21)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[2]], i22)
+        self.assertTrue(b.equals(visitor.pyomo_to_docplex[m.b] == 1))
+
     def test_using_precedence_expr_as_boolean_expr_negative_delay(self):
         m = self.get_model()
         e = m.b.implies(m.i2[2].start_time.at(m.i2[1].start_time, delay=-3))
@@ -703,6 +858,10 @@ def test_using_precedence_expr_as_boolean_expr_negative_delay(self):
             expr[1].equals(cp.if_then(b, cp.start_of(i22) + (-3) == cp.start_of(i21)))
         )
 
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[1]], i21)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[2]], i22)
+        self.assertTrue(b.equals(visitor.pyomo_to_docplex[m.b] == 1))
+
 
 @unittest.skipIf(not docplex_available, "docplex is not available")
 class TestCPExpressionWalker_IntervalVars(CommonTest):
@@ -716,6 +875,7 @@ def test_interval_var_fixed_presences_correct(self):
         i = visitor.var_map[id(m.i)]
         # Check that docplex knows it's optional
         self.assertTrue(i.is_optional())
+        self.assertIs(visitor.pyomo_to_docplex[m.i], i)
 
         # Now fix it to absent
         m.i.is_present.fix(False)
@@ -726,8 +886,10 @@ def test_interval_var_fixed_presences_correct(self):
 
         self.assertIn(id(m.i2[1]), visitor.var_map)
         i21 = visitor.var_map[id(m.i2[1])]
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[1]], i21)
         self.assertIn(id(m.i), visitor.var_map)
         i = visitor.var_map[id(m.i)]
+        self.assertIs(visitor.pyomo_to_docplex[m.i], i)
 
         # Check that we passed on the presence info to docplex
         self.assertTrue(i.is_absent())
@@ -746,6 +908,7 @@ def test_interval_var_fixed_length(self):
 
         self.assertIn(id(m.i), visitor.var_map)
         i = visitor.var_map[id(m.i)]
+        self.assertIs(visitor.pyomo_to_docplex[m.i], i)
 
         self.assertTrue(i.is_optional())
         self.assertEqual(i.get_length(), (4, 4))
@@ -763,12 +926,85 @@ def test_interval_var_fixed_start_and_end(self):
 
         self.assertIn(id(m.i), visitor.var_map)
         i = visitor.var_map[id(m.i)]
+        self.assertIs(visitor.pyomo_to_docplex[m.i], i)
 
         self.assertFalse(i.is_optional())
         self.assertEqual(i.get_start(), (3, 3))
         self.assertEqual(i.get_end(), (6, 6))
 
 
+@unittest.skipIf(not docplex_available, "docplex is not available")
+class TestCPExpressionWalker_SequenceVars(CommonTest):
+    def get_model(self):
+        m = super().get_model()
+        m.seq = SequenceVar(expr=[m.i, m.i2[1], m.i2[2]])
+
+        return m
+
+    def check_scalar_sequence_var(self, m, visitor):
+        self.assertIn(id(m.seq), visitor.var_map)
+        seq = visitor.var_map[id(m.seq)]
+        self.assertIs(visitor.pyomo_to_docplex[m.seq], seq)
+
+        i = visitor.var_map[id(m.i)]
+        i21 = visitor.var_map[id(m.i2[1])]
+        i22 = visitor.var_map[id(m.i2[2])]
+        self.assertIs(visitor.pyomo_to_docplex[m.i], i)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[1]], i21)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[2]], i22)
+
+        ivs = seq.get_interval_variables()
+        self.assertEqual(len(ivs), 3)
+        self.assertIs(ivs[0], i)
+        self.assertIs(ivs[1], i21)
+        self.assertIs(ivs[2], i22)
+
+        return seq, i, i21, i22
+
+    def test_scalar_sequence_var(self):
+        m = self.get_model()
+
+        visitor = self.get_visitor()
+        expr = visitor.walk_expression((m.seq, m.seq, 0))
+        self.check_scalar_sequence_var(m, visitor)
+
+    def test_no_overlap(self):
+        m = self.get_model()
+        e = no_overlap(m.seq)
+        visitor = self.get_visitor()
+        expr = visitor.walk_expression((e, e, 0))
+
+        seq, i, i21, i22 = self.check_scalar_sequence_var(m, visitor)
+        self.assertTrue(expr[1].equals(cp.no_overlap(seq)))
+
+    def test_first_in_sequence(self):
+        m = self.get_model()
+        e = first_in_sequence(m.i2[1], m.seq)
+        visitor = self.get_visitor()
+        expr = visitor.walk_expression((e, e, 0))
+
+        seq, i, i21, i22 = self.check_scalar_sequence_var(m, visitor)
+        self.assertTrue(expr[1].equals(cp.first(seq, i21)))
+
+    def test_before_in_sequence(self):
+        m = self.get_model()
+        e = last_in_sequence(m.i, m.seq)
+        visitor = self.get_visitor()
+        expr = visitor.walk_expression((e, e, 0))
+
+        seq, i, i21, i22 = self.check_scalar_sequence_var(m, visitor)
+        self.assertTrue(expr[1].equals(cp.last(seq, i)))
+
+    def test_last_in_sequence(self):
+        m = self.get_model()
+        e = last_in_sequence(m.i2[1], m.seq)
+        visitor = self.get_visitor()
+        expr = visitor.walk_expression((e, e, 0))
+
+        seq, i, i21, i22 = self.check_scalar_sequence_var(m, visitor)
+        self.assertTrue(expr[1].equals(cp.last(seq, i21)))
+
+
 @unittest.skipIf(not docplex_available, "docplex is not available")
 class TestCPExpressionWalker_PrecedenceExpressions(CommonTest):
     def test_start_before_start(self):
@@ -782,6 +1018,8 @@ def test_start_before_start(self):
 
         i = visitor.var_map[id(m.i)]
         i21 = visitor.var_map[id(m.i2[1])]
+        self.assertIs(visitor.pyomo_to_docplex[m.i], i)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[1]], i21)
 
         self.assertTrue(expr[1].equals(cp.start_before_start(i, i21, 0)))
 
@@ -796,6 +1034,8 @@ def test_start_before_end(self):
 
         i = visitor.var_map[id(m.i)]
         i21 = visitor.var_map[id(m.i2[1])]
+        self.assertIs(visitor.pyomo_to_docplex[m.i], i)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[1]], i21)
 
         self.assertTrue(expr[1].equals(cp.start_before_end(i, i21, 3)))
 
@@ -810,6 +1050,8 @@ def test_end_before_start(self):
 
         i = visitor.var_map[id(m.i)]
         i21 = visitor.var_map[id(m.i2[1])]
+        self.assertIs(visitor.pyomo_to_docplex[m.i], i)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[1]], i21)
 
         self.assertTrue(expr[1].equals(cp.end_before_start(i, i21, -2)))
 
@@ -824,6 +1066,8 @@ def test_end_before_end(self):
 
         i = visitor.var_map[id(m.i)]
         i21 = visitor.var_map[id(m.i2[1])]
+        self.assertIs(visitor.pyomo_to_docplex[m.i], i)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[1]], i21)
 
         self.assertTrue(expr[1].equals(cp.end_before_end(i, i21, 6)))
 
@@ -838,6 +1082,8 @@ def test_start_at_start(self):
 
         i = visitor.var_map[id(m.i)]
         i21 = visitor.var_map[id(m.i2[1])]
+        self.assertIs(visitor.pyomo_to_docplex[m.i], i)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[1]], i21)
 
         self.assertTrue(expr[1].equals(cp.start_at_start(i, i21, 0)))
 
@@ -852,6 +1098,8 @@ def test_start_at_end(self):
 
         i = visitor.var_map[id(m.i)]
         i21 = visitor.var_map[id(m.i2[1])]
+        self.assertIs(visitor.pyomo_to_docplex[m.i], i)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[1]], i21)
 
         self.assertTrue(expr[1].equals(cp.start_at_end(i, i21, 3)))
 
@@ -866,6 +1114,8 @@ def test_end_at_start(self):
 
         i = visitor.var_map[id(m.i)]
         i21 = visitor.var_map[id(m.i2[1])]
+        self.assertIs(visitor.pyomo_to_docplex[m.i], i)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[1]], i21)
 
         self.assertTrue(expr[1].equals(cp.end_at_start(i, i21, -2)))
 
@@ -880,6 +1130,8 @@ def test_end_at_end(self):
 
         i = visitor.var_map[id(m.i)]
         i21 = visitor.var_map[id(m.i2[1])]
+        self.assertIs(visitor.pyomo_to_docplex[m.i], i)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[1]], i21)
 
         self.assertTrue(expr[1].equals(cp.end_at_end(i, i21, 6)))
 
@@ -904,6 +1156,10 @@ def test_indirection_before_constraint(self):
         i21 = visitor.var_map[id(m.i2[1])]
         i22 = visitor.var_map[id(m.i2[2])]
         i = visitor.var_map[id(m.i)]
+        self.assertIs(visitor.pyomo_to_docplex[m.y], y)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[1]], i21)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[2]], i22)
+        self.assertIs(visitor.pyomo_to_docplex[m.i], i)
 
         self.assertTrue(
             expr[1].equals(
@@ -930,6 +1186,10 @@ def test_indirection_after_constraint(self):
         i21 = visitor.var_map[id(m.i2[1])]
         i22 = visitor.var_map[id(m.i2[2])]
         i = visitor.var_map[id(m.i)]
+        self.assertIs(visitor.pyomo_to_docplex[m.y], y)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[1]], i21)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[2]], i22)
+        self.assertIs(visitor.pyomo_to_docplex[m.i], i)
 
         self.assertTrue(
             expr[1].equals(
@@ -957,6 +1217,10 @@ def test_indirection_at_constraint(self):
         i21 = visitor.var_map[id(m.i2[1])]
         i22 = visitor.var_map[id(m.i2[2])]
         i = visitor.var_map[id(m.i)]
+        self.assertIs(visitor.pyomo_to_docplex[m.y], y)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[1]], i21)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[2]], i22)
+        self.assertIs(visitor.pyomo_to_docplex[m.i], i)
 
         self.assertTrue(
             expr[1].equals(
@@ -984,6 +1248,10 @@ def test_before_indirection_constraint(self):
         i21 = visitor.var_map[id(m.i2[1])]
         i22 = visitor.var_map[id(m.i2[2])]
         i = visitor.var_map[id(m.i)]
+        self.assertIs(visitor.pyomo_to_docplex[m.y], y)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[1]], i21)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[2]], i22)
+        self.assertIs(visitor.pyomo_to_docplex[m.i], i)
 
         self.assertTrue(
             expr[1].equals(
@@ -1009,6 +1277,10 @@ def test_after_indirection_constraint(self):
         i21 = visitor.var_map[id(m.i2[1])]
         i22 = visitor.var_map[id(m.i2[2])]
         i = visitor.var_map[id(m.i)]
+        self.assertIs(visitor.pyomo_to_docplex[m.y], y)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[1]], i21)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[2]], i22)
+        self.assertIs(visitor.pyomo_to_docplex[m.i], i)
 
         self.assertTrue(
             expr[1].equals(
@@ -1034,6 +1306,10 @@ def test_at_indirection_constraint(self):
         i21 = visitor.var_map[id(m.i2[1])]
         i22 = visitor.var_map[id(m.i2[2])]
         i = visitor.var_map[id(m.i)]
+        self.assertIs(visitor.pyomo_to_docplex[m.y], y)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[1]], i21)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[2]], i22)
+        self.assertIs(visitor.pyomo_to_docplex[m.i], i)
 
         self.assertTrue(
             expr[1].equals(
@@ -1068,6 +1344,13 @@ def test_double_indirection_before_constraint(self):
         i33 = visitor.var_map[id(m.i3[1, 3])]
         i34 = visitor.var_map[id(m.i3[1, 4])]
         i35 = visitor.var_map[id(m.i3[1, 5])]
+        self.assertIs(visitor.pyomo_to_docplex[m.y], y)
+        self.assertIs(visitor.pyomo_to_docplex[m.x], x)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[1]], i21)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[2]], i22)
+        self.assertIs(visitor.pyomo_to_docplex[m.i3[1, 3]], i33)
+        self.assertIs(visitor.pyomo_to_docplex[m.i3[1, 4]], i34)
+        self.assertIs(visitor.pyomo_to_docplex[m.i3[1, 5]], i35)
 
         self.assertTrue(
             expr[1].equals(
@@ -1105,6 +1388,13 @@ def test_double_indirection_after_constraint(self):
         i33 = visitor.var_map[id(m.i3[1, 3])]
         i34 = visitor.var_map[id(m.i3[1, 4])]
         i35 = visitor.var_map[id(m.i3[1, 5])]
+        self.assertIs(visitor.pyomo_to_docplex[m.y], y)
+        self.assertIs(visitor.pyomo_to_docplex[m.x], x)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[1]], i21)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[2]], i22)
+        self.assertIs(visitor.pyomo_to_docplex[m.i3[1, 3]], i33)
+        self.assertIs(visitor.pyomo_to_docplex[m.i3[1, 4]], i34)
+        self.assertIs(visitor.pyomo_to_docplex[m.i3[1, 5]], i35)
 
         self.assertTrue(
             expr[1].equals(
@@ -1140,6 +1430,13 @@ def test_double_indirection_at_constraint(self):
         i33 = visitor.var_map[id(m.i3[1, 3])]
         i34 = visitor.var_map[id(m.i3[1, 4])]
         i35 = visitor.var_map[id(m.i3[1, 5])]
+        self.assertIs(visitor.pyomo_to_docplex[m.y], y)
+        self.assertIs(visitor.pyomo_to_docplex[m.x], x)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[1]], i21)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[2]], i22)
+        self.assertIs(visitor.pyomo_to_docplex[m.i3[1, 3]], i33)
+        self.assertIs(visitor.pyomo_to_docplex[m.i3[1, 4]], i34)
+        self.assertIs(visitor.pyomo_to_docplex[m.i3[1, 5]], i35)
 
         self.assertTrue(
             expr[1].equals(
@@ -1187,10 +1484,91 @@ def param_rule(m, i):
         self.assertIn(id(m.a), visitor.var_map)
         x = visitor.var_map[id(m.x)]
         a = visitor.var_map[id(m.a)]
+        self.assertIs(visitor.pyomo_to_docplex[m.x], x)
+        self.assertIs(visitor.pyomo_to_docplex[m.a], a)
 
         self.assertTrue(expr[1].equals(cp.element([2, 4, 6], 0 + 1 * (x - 1) // 2) / a))
 
 
+@unittest.skipIf(not docplex_available, "docplex is not available")
+class TestCPExpressionWalker_HierarchicalScheduling(CommonTest):
+    def get_model(self):
+        m = ConcreteModel()
+
+        def start_rule(m, i):
+            return 2 * i
+
+        def length_rule(m, i):
+            return i
+
+        m.iv = IntervalVar(
+            [1, 2, 3], start=start_rule, length=length_rule, optional=True
+        )
+        m.whole_enchilada = IntervalVar()
+
+        return m
+
+    def test_spans(self):
+        m = self.get_model()
+        e = m.whole_enchilada.spans(m.iv[i] for i in [1, 2, 3])
+
+        visitor = self.get_visitor()
+        expr = visitor.walk_expression((e, e, 0))
+
+        self.assertIn(id(m.whole_enchilada), visitor.var_map)
+        whole_enchilada = visitor.var_map[id(m.whole_enchilada)]
+        self.assertIs(visitor.pyomo_to_docplex[m.whole_enchilada], whole_enchilada)
+
+        iv = {}
+        for i in [1, 2, 3]:
+            self.assertIn(id(m.iv[i]), visitor.var_map)
+            iv[i] = visitor.var_map[id(m.iv[i])]
+
+        self.assertTrue(
+            expr[1].equals(cp.span(whole_enchilada, [iv[i] for i in [1, 2, 3]]))
+        )
+
+    def test_alternative(self):
+        m = self.get_model()
+        e = alternative(m.whole_enchilada, [m.iv[i] for i in [1, 2, 3]])
+
+        visitor = self.get_visitor()
+        expr = visitor.walk_expression((e, e, 0))
+
+        self.assertIn(id(m.whole_enchilada), visitor.var_map)
+        whole_enchilada = visitor.var_map[id(m.whole_enchilada)]
+        self.assertIs(visitor.pyomo_to_docplex[m.whole_enchilada], whole_enchilada)
+
+        iv = {}
+        for i in [1, 2, 3]:
+            self.assertIn(id(m.iv[i]), visitor.var_map)
+            iv[i] = visitor.var_map[id(m.iv[i])]
+
+        self.assertTrue(
+            expr[1].equals(cp.alternative(whole_enchilada, [iv[i] for i in [1, 2, 3]]))
+        )
+
+    def test_synchronize(self):
+        m = self.get_model()
+        e = synchronize(m.whole_enchilada, [m.iv[i] for i in [1, 2, 3]])
+
+        visitor = self.get_visitor()
+        expr = visitor.walk_expression((e, e, 0))
+
+        self.assertIn(id(m.whole_enchilada), visitor.var_map)
+        whole_enchilada = visitor.var_map[id(m.whole_enchilada)]
+        self.assertIs(visitor.pyomo_to_docplex[m.whole_enchilada], whole_enchilada)
+
+        iv = {}
+        for i in [1, 2, 3]:
+            self.assertIn(id(m.iv[i]), visitor.var_map)
+            iv[i] = visitor.var_map[id(m.iv[i])]
+
+        self.assertTrue(
+            expr[1].equals(cp.synchronize(whole_enchilada, [iv[i] for i in [1, 2, 3]]))
+        )
+
+
 @unittest.skipIf(not docplex_available, "docplex is not available")
 class TestCPExpressionWalker_CumulFuncExpressions(CommonTest):
     def test_always_in(self):
@@ -1212,6 +1590,9 @@ def test_always_in(self):
         i = visitor.var_map[id(m.i)]
         i21 = visitor.var_map[id(m.i2[1])]
         i22 = visitor.var_map[id(m.i2[2])]
+        self.assertIs(visitor.pyomo_to_docplex[m.i], i)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[1]], i21)
+        self.assertIs(visitor.pyomo_to_docplex[m.i2[2]], i22)
 
         self.assertTrue(
             expr[1].equals(
@@ -1227,6 +1608,24 @@ def test_always_in(self):
             )
         )
 
+    def test_always_in_single_pulse(self):
+        # This is a bit silly as you can tell whether or not it is feasible
+        # structurally, but there's no reason it couldn't happen.
+        m = self.get_model()
+        f = Pulse((m.i, 3))
+        m.c = LogicalConstraint(expr=f.within((0, 3), (0, 10)))
+        visitor = self.get_visitor()
+        expr = visitor.walk_expression((m.c.expr, m.c, 0))
+
+        self.assertIn(id(m.i), visitor.var_map)
+
+        i = visitor.var_map[id(m.i)]
+        self.assertIs(visitor.pyomo_to_docplex[m.i], i)
+
+        self.assertTrue(
+            expr[1].equals(cp.always_in(cp.pulse(i, 3), interval=(0, 10), min=0, max=3))
+        )
+
 
 @unittest.skipIf(not docplex_available, "docplex is not available")
 class TestCPExpressionWalker_NamedExpressions(CommonTest):
@@ -1240,6 +1639,7 @@ def test_named_expression(self):
 
         self.assertIn(id(m.x), visitor.var_map)
         x = visitor.var_map[id(m.x)]
+        self.assertIs(visitor.pyomo_to_docplex[m.x], x)
 
         self.assertTrue(expr[1].equals(x**2 + 7))
 
@@ -1253,6 +1653,7 @@ def test_repeated_named_expression(self):
 
         self.assertIn(id(m.x), visitor.var_map)
         x = visitor.var_map[id(m.x)]
+        self.assertIs(visitor.pyomo_to_docplex[m.x], x)
 
         self.assertTrue(expr[1].equals(x**2 + 7 + (-1) * (8 * (x**2 + 7))))
 
@@ -1283,6 +1684,7 @@ def test_fixed_integer_var(self):
 
         self.assertIn(id(m.a[2]), visitor.var_map)
         a2 = visitor.var_map[id(m.a[2])]
+        self.assertIs(visitor.pyomo_to_docplex[m.a[2]], a2)
 
         self.assertTrue(expr[1].equals(3 + a2))
 
@@ -1297,6 +1699,7 @@ def test_fixed_boolean_var(self):
 
         self.assertIn(id(m.b2['b']), visitor.var_map)
         b2b = visitor.var_map[id(m.b2['b'])]
+        self.assertTrue(b2b.equals(visitor.pyomo_to_docplex[m.b2['b']] == 1))
 
         self.assertTrue(expr[1].equals(cp.logical_or(False, cp.logical_and(True, b2b))))
 
@@ -1310,13 +1713,16 @@ def test_indirection_single_index(self):
 
         self.assertIn(id(m.x), visitor.var_map)
         x = visitor.var_map[id(m.x)]
+        self.assertIs(visitor.pyomo_to_docplex[m.x], x)
         a = []
         # only need indices 6, 7, and 8 from a, since that's what x is capable
         # of selecting.
         for idx in [6, 7, 8]:
             v = m.a[idx]
             self.assertIn(id(v), visitor.var_map)
-            a.append(visitor.var_map[id(v)])
+            cpx_v = visitor.var_map[id(v)]
+            self.assertIs(visitor.pyomo_to_docplex[v], cpx_v)
+            a.append(cpx_v)
         # since x is between 6 and 8, we subtract 6 from it for it to be the
         # right index
         self.assertTrue(expr[1].equals(cp.element(a, 0 + 1 * (x - 6) // 1)))
@@ -1334,8 +1740,10 @@ def test_indirection_multi_index_second_constant(self):
         for i in [6, 7, 8]:
             self.assertIn(id(m.z[i, 3]), visitor.var_map)
             z[i, 3] = visitor.var_map[id(m.z[i, 3])]
+            self.assertIs(visitor.pyomo_to_docplex[m.z[i, 3]], z[i, 3])
         self.assertIn(id(m.x), visitor.var_map)
         x = visitor.var_map[id(m.x)]
+        self.assertIs(visitor.pyomo_to_docplex[m.x], x)
 
         self.assertTrue(
             expr[1].equals(
@@ -1356,8 +1764,11 @@ def test_indirection_multi_index_first_constant(self):
         for i in [6, 7, 8]:
             self.assertIn(id(m.z[3, i]), visitor.var_map)
             z[3, i] = visitor.var_map[id(m.z[3, i])]
+            self.assertIs(visitor.pyomo_to_docplex[m.z[3, i]], z[3, i])
+
         self.assertIn(id(m.x), visitor.var_map)
         x = visitor.var_map[id(m.x)]
+        self.assertIs(visitor.pyomo_to_docplex[m.x], x)
 
         self.assertTrue(
             expr[1].equals(
@@ -1379,8 +1790,11 @@ def test_indirection_multi_index_neither_constant_same_var(self):
             for j in [6, 7, 8]:
                 self.assertIn(id(m.z[i, j]), visitor.var_map)
                 z[i, j] = visitor.var_map[id(m.z[i, j])]
+                self.assertIs(visitor.pyomo_to_docplex[m.z[i, j]], z[i, j])
+
         self.assertIn(id(m.x), visitor.var_map)
         x = visitor.var_map[id(m.x)]
+        self.assertIs(visitor.pyomo_to_docplex[m.x], x)
 
         self.assertTrue(
             expr[1].equals(
@@ -1404,12 +1818,17 @@ def test_indirection_multi_index_neither_constant_diff_vars(self):
         z = {}
         for i in [6, 7, 8]:
             for j in [1, 3, 5]:
-                self.assertIn(id(m.z[i, 3]), visitor.var_map)
+                self.assertIn(id(m.z[i, j]), visitor.var_map)
                 z[i, j] = visitor.var_map[id(m.z[i, j])]
+                self.assertIs(visitor.pyomo_to_docplex[m.z[i, j]], z[i, j])
+
         self.assertIn(id(m.x), visitor.var_map)
         x = visitor.var_map[id(m.x)]
+        self.assertIs(visitor.pyomo_to_docplex[m.x], x)
+
         self.assertIn(id(m.y), visitor.var_map)
         y = visitor.var_map[id(m.y)]
+        self.assertIs(visitor.pyomo_to_docplex[m.y], y)
 
         self.assertTrue(
             expr[1].equals(
@@ -1434,10 +1853,14 @@ def test_indirection_expression_index(self):
         for i in range(1, 8):
             self.assertIn(id(m.a[i]), visitor.var_map)
             a[i] = visitor.var_map[id(m.a[i])]
+            self.assertIs(visitor.pyomo_to_docplex[m.a[i]], a[i])
+
         self.assertIn(id(m.x), visitor.var_map)
         x = visitor.var_map[id(m.x)]
+        self.assertIs(visitor.pyomo_to_docplex[m.x], x)
         self.assertIn(id(m.y), visitor.var_map)
         y = visitor.var_map[id(m.y)]
+        self.assertIs(visitor.pyomo_to_docplex[m.y], y)
 
         self.assertTrue(
             expr[1].equals(
diff --git a/pyomo/contrib/cp/tests/test_docplex_writer.py b/pyomo/contrib/cp/tests/test_docplex_writer.py
index d569ef2e696..4f6039993c3 100644
--- a/pyomo/contrib/cp/tests/test_docplex_writer.py
+++ b/pyomo/contrib/cp/tests/test_docplex_writer.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -12,13 +12,25 @@
 import pyomo.common.unittest as unittest
 from pyomo.common.fileutils import Executable
 
-from pyomo.contrib.cp import IntervalVar, Pulse, Step, AlwaysIn
+from pyomo.contrib.cp import (
+    IntervalVar,
+    SequenceVar,
+    Pulse,
+    Step,
+    AlwaysIn,
+    first_in_sequence,
+    predecessor_to,
+    no_overlap,
+)
 from pyomo.contrib.cp.repn.docplex_writer import LogicalToDoCplex
 from pyomo.environ import (
+    all_different,
+    count_if,
     ConcreteModel,
     Set,
     Var,
     Integers,
+    Param,
     LogicalConstraint,
     implies,
     value,
@@ -254,3 +266,159 @@ def x_bounds(m, i):
         self.assertEqual(results.problem.sense, minimize)
         self.assertEqual(results.problem.lower_bound, 6)
         self.assertEqual(results.problem.upper_bound, 6)
+
+    def test_matching_problem(self):
+        m = ConcreteModel()
+
+        m.People = Set(initialize=['P1', 'P2', 'P3', 'P4', 'P5', 'P6', 'P7'])
+        m.Languages = Set(initialize=['English', 'Spanish', 'Hindi', 'Swedish'])
+        # People have integer names because we don't have categorical vars yet.
+        m.Names = Set(initialize=range(len(m.People)))
+
+        m.Observed = Param(
+            m.Names,
+            m.Names,
+            m.Languages,
+            initialize={
+                (0, 1, 'English'): 1,
+                (1, 0, 'English'): 1,
+                (0, 2, 'English'): 1,
+                (2, 0, 'English'): 1,
+                (0, 3, 'English'): 1,
+                (3, 0, 'English'): 1,
+                (0, 4, 'English'): 1,
+                (4, 0, 'English'): 1,
+                (0, 5, 'English'): 1,
+                (5, 0, 'English'): 1,
+                (0, 6, 'English'): 1,
+                (6, 0, 'English'): 1,
+                (1, 2, 'Spanish'): 1,
+                (2, 1, 'Spanish'): 1,
+                (1, 5, 'Hindi'): 1,
+                (5, 1, 'Hindi'): 1,
+                (1, 6, 'Hindi'): 1,
+                (6, 1, 'Hindi'): 1,
+                (2, 3, 'Swedish'): 1,
+                (3, 2, 'Swedish'): 1,
+                (3, 4, 'English'): 1,
+                (4, 3, 'English'): 1,
+            },
+            default=0,
+            mutable=True,
+        )  # TODO: shouldn't need to
+        # be mutable, but waiting
+        # on #3045
+
+        m.Expected = Param(
+            m.People,
+            m.People,
+            m.Languages,
+            initialize={
+                ('P1', 'P2', 'English'): 1,
+                ('P2', 'P1', 'English'): 1,
+                ('P1', 'P3', 'English'): 1,
+                ('P3', 'P1', 'English'): 1,
+                ('P1', 'P4', 'English'): 1,
+                ('P4', 'P1', 'English'): 1,
+                ('P1', 'P5', 'English'): 1,
+                ('P5', 'P1', 'English'): 1,
+                ('P1', 'P6', 'English'): 1,
+                ('P6', 'P1', 'English'): 1,
+                ('P1', 'P7', 'English'): 1,
+                ('P7', 'P1', 'English'): 1,
+                ('P2', 'P3', 'Spanish'): 1,
+                ('P3', 'P2', 'Spanish'): 1,
+                ('P2', 'P6', 'Hindi'): 1,
+                ('P6', 'P2', 'Hindi'): 1,
+                ('P2', 'P7', 'Hindi'): 1,
+                ('P7', 'P2', 'Hindi'): 1,
+                ('P3', 'P4', 'Swedish'): 1,
+                ('P4', 'P3', 'Swedish'): 1,
+                ('P4', 'P5', 'English'): 1,
+                ('P5', 'P4', 'English'): 1,
+            },
+            default=0,
+            mutable=True,
+        )  # TODO: shouldn't need to be mutable, but
+        # waiting on #3045
+
+        m.person_name = Var(m.People, bounds=(0, max(m.Names)), domain=Integers)
+
+        m.one_to_one = LogicalConstraint(
+            expr=all_different(m.person_name[person] for person in m.People)
+        )
+
+        m.obj = Objective(
+            expr=count_if(
+                m.Observed[m.person_name[p1], m.person_name[p2], l]
+                == m.Expected[p1, p2, l]
+                for p1 in m.People
+                for p2 in m.People
+                for l in m.Languages
+            ),
+            sense=maximize,
+        )
+
+        results = SolverFactory('cp_optimizer').solve(m)
+
+        # we can get one of two perfect matches:
+        perfect = 7 * 7 * 4
+        self.assertEqual(results.problem.lower_bound, perfect)
+        self.assertEqual(results.problem.upper_bound, perfect)
+        self.assertEqual(
+            results.solver.termination_condition, TerminationCondition.optimal
+        )
+        self.assertEqual(value(m.obj), perfect)
+        self.assertEqual(value(m.person_name['P1']), 0)
+        self.assertEqual(value(m.person_name['P2']), 1)
+        self.assertEqual(value(m.person_name['P3']), 2)
+        self.assertEqual(value(m.person_name['P4']), 3)
+        self.assertEqual(value(m.person_name['P5']), 4)
+        # We can't distinguish P6 and P7, so they could each have either of
+        # names 5 and 6
+        self.assertTrue(
+            value(m.person_name['P6']) == 5 or value(m.person_name['P6']) == 6
+        )
+        self.assertTrue(
+            value(m.person_name['P7']) == 5 or value(m.person_name['P7']) == 6
+        )
+
+        m.person_name['P6'].fix(5)
+        m.person_name['P7'].fix(6)
+
+        results = SolverFactory('cp_optimizer').solve(m)
+        self.assertEqual(
+            results.solver.termination_condition, TerminationCondition.optimal
+        )
+        self.assertEqual(value(m.obj), perfect)
+
+        m.person_name['P6'].fix(6)
+        m.person_name['P7'].fix(5)
+
+        results = SolverFactory('cp_optimizer').solve(m)
+        self.assertEqual(
+            results.solver.termination_condition, TerminationCondition.optimal
+        )
+        self.assertEqual(value(m.obj), perfect)
+
+    def test_scheduling_with_sequence_vars(self):
+        m = ConcreteModel()
+        m.Steps = Set(initialize=[1, 2, 3])
+
+        def length_rule(m, j):
+            return 2 * j
+
+        m.i = IntervalVar(m.Steps, start=(0, 12), end=(0, 12), length=length_rule)
+        m.seq = SequenceVar(expr=[m.i[j] for j in m.Steps])
+        m.first = LogicalConstraint(expr=first_in_sequence(m.i[1], m.seq))
+        m.seq_order1 = LogicalConstraint(expr=predecessor_to(m.i[1], m.i[2], m.seq))
+        m.seq_order2 = LogicalConstraint(expr=predecessor_to(m.i[2], m.i[3], m.seq))
+        m.no_ovlerpa = LogicalConstraint(expr=no_overlap(m.seq))
+
+        results = SolverFactory('cp_optimizer').solve(m)
+        self.assertEqual(
+            results.solver.termination_condition, TerminationCondition.feasible
+        )
+        self.assertEqual(value(m.i[1].start_time), 0)
+        self.assertEqual(value(m.i[2].start_time), 2)
+        self.assertEqual(value(m.i[3].start_time), 6)
diff --git a/pyomo/contrib/cp/tests/test_interval_var.py b/pyomo/contrib/cp/tests/test_interval_var.py
index edbf889fcda..e44ba00210d 100644
--- a/pyomo/contrib/cp/tests/test_interval_var.py
+++ b/pyomo/contrib/cp/tests/test_interval_var.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -17,7 +17,7 @@
     IntervalVarPresence,
 )
 from pyomo.core.expr import GetItemExpression, GetAttrExpression
-from pyomo.environ import ConcreteModel, Integers, Set, value, Var
+from pyomo.environ import ConcreteModel, Integers, Reference, Set, value, Var
 
 
 class TestScalarIntervalVar(unittest.TestCase):
@@ -217,5 +217,24 @@ def test_index_by_expr(self):
         self.assertIs(thing2.args[0], thing1)
         self.assertEqual(thing2.args[1], 'start_time')
 
-        # TODO: But this is where it dies.
         expr1 = m.act[m.i, 2].start_time.before(m.act[m.i**2, 1].end_time)
+
+    def test_reference(self):
+        m = ConcreteModel()
+        m.act = IntervalVar([1, 2], end=[0, 10], optional=True)
+
+        thing = Reference(m.act[:].is_present)
+        self.assertIs(thing[1], m.act[1].is_present)
+        self.assertIs(thing[2], m.act[2].is_present)
+
+        thing = Reference(m.act[:].start_time)
+        self.assertIs(thing[1], m.act[1].start_time)
+        self.assertIs(thing[2], m.act[2].start_time)
+
+        thing = Reference(m.act[:].end_time)
+        self.assertIs(thing[1], m.act[1].end_time)
+        self.assertIs(thing[2], m.act[2].end_time)
+
+        thing = Reference(m.act[:].length)
+        self.assertIs(thing[1], m.act[1].length)
+        self.assertIs(thing[2], m.act[2].length)
diff --git a/pyomo/contrib/cp/tests/test_logical_to_disjunctive.py b/pyomo/contrib/cp/tests/test_logical_to_disjunctive.py
index c6733f34f83..3f66aa57726 100755
--- a/pyomo/contrib/cp/tests/test_logical_to_disjunctive.py
+++ b/pyomo/contrib/cp/tests/test_logical_to_disjunctive.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/cp/tests/test_precedence_constraints.py b/pyomo/contrib/cp/tests/test_precedence_constraints.py
index 461dabf564c..3faf054f241 100644
--- a/pyomo/contrib/cp/tests/test_precedence_constraints.py
+++ b/pyomo/contrib/cp/tests/test_precedence_constraints.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -15,7 +15,7 @@
     BeforeExpression,
     AtExpression,
 )
-from pyomo.environ import ConcreteModel, LogicalConstraint
+from pyomo.environ import ConcreteModel, LogicalConstraint, Param
 
 
 class TestPrecedenceRelationships(unittest.TestCase):
@@ -173,3 +173,17 @@ def test_end_after_end(self):
         self.assertEqual(m.c.expr.delay, 0)
 
         self.assertEqual(str(m.c.expr), "b.end_time <= a.end_time")
+
+    def test_end_before_start_param_delay(self):
+        m = self.get_model()
+        m.PrepTime = Param(initialize=5)
+        m.c = LogicalConstraint(
+            expr=m.a.end_time.before(m.b.start_time, delay=m.PrepTime)
+        )
+        self.assertIsInstance(m.c.expr, BeforeExpression)
+        self.assertEqual(len(m.c.expr.args), 3)
+        self.assertIs(m.c.expr.args[0], m.a.end_time)
+        self.assertIs(m.c.expr.args[1], m.b.start_time)
+        self.assertIs(m.c.expr.delay, m.PrepTime)
+
+        self.assertEqual(str(m.c.expr), "a.end_time + PrepTime <= b.start_time")
diff --git a/pyomo/contrib/cp/tests/test_sequence_expressions.py b/pyomo/contrib/cp/tests/test_sequence_expressions.py
new file mode 100644
index 00000000000..c7cf94f23d5
--- /dev/null
+++ b/pyomo/contrib/cp/tests/test_sequence_expressions.py
@@ -0,0 +1,175 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import pyomo.common.unittest as unittest
+from pyomo.contrib.cp.interval_var import IntervalVar
+from pyomo.contrib.cp.scheduling_expr.scheduling_logic import (
+    AlternativeExpression,
+    SpanExpression,
+    SynchronizeExpression,
+    alternative,
+    spans,
+    synchronize,
+)
+from pyomo.contrib.cp.scheduling_expr.sequence_expressions import (
+    NoOverlapExpression,
+    FirstInSequenceExpression,
+    LastInSequenceExpression,
+    BeforeInSequenceExpression,
+    PredecessorToExpression,
+    no_overlap,
+    predecessor_to,
+    before_in_sequence,
+    first_in_sequence,
+    last_in_sequence,
+)
+from pyomo.contrib.cp.sequence_var import SequenceVar
+from pyomo.environ import ConcreteModel, LogicalConstraint, Set
+
+
+class TestSequenceVarExpressions(unittest.TestCase):
+    def get_model(self):
+        m = ConcreteModel()
+        m.S = Set(initialize=range(3))
+        m.i = IntervalVar(m.S, start=(0, 5))
+        m.seq = SequenceVar(expr=[m.i[j] for j in m.S])
+
+        return m
+
+    def test_no_overlap(self):
+        m = self.get_model()
+        m.c = LogicalConstraint(expr=no_overlap(m.seq))
+        e = m.c.expr
+
+        self.assertIsInstance(e, NoOverlapExpression)
+        self.assertEqual(e.nargs(), 1)
+        self.assertEqual(len(e.args), 1)
+        self.assertIs(e.args[0], m.seq)
+
+        self.assertEqual(str(e), "no_overlap(seq)")
+
+    def test_first_in_sequence(self):
+        m = self.get_model()
+        m.c = LogicalConstraint(expr=first_in_sequence(m.i[2], m.seq))
+        e = m.c.expr
+
+        self.assertIsInstance(e, FirstInSequenceExpression)
+        self.assertEqual(e.nargs(), 2)
+        self.assertEqual(len(e.args), 2)
+        self.assertIs(e.args[0], m.i[2])
+        self.assertIs(e.args[1], m.seq)
+
+        self.assertEqual(str(e), "first_in(i[2], seq)")
+
+    def test_last_in_sequence(self):
+        m = self.get_model()
+        m.c = LogicalConstraint(expr=last_in_sequence(m.i[0], m.seq))
+        e = m.c.expr
+
+        self.assertIsInstance(e, LastInSequenceExpression)
+        self.assertEqual(e.nargs(), 2)
+        self.assertEqual(len(e.args), 2)
+        self.assertIs(e.args[0], m.i[0])
+        self.assertIs(e.args[1], m.seq)
+
+        self.assertEqual(str(e), "last_in(i[0], seq)")
+
+    def test_before_in_sequence(self):
+        m = self.get_model()
+        m.c = LogicalConstraint(expr=before_in_sequence(m.i[1], m.i[0], m.seq))
+        e = m.c.expr
+
+        self.assertIsInstance(e, BeforeInSequenceExpression)
+        self.assertEqual(e.nargs(), 3)
+        self.assertEqual(len(e.args), 3)
+        self.assertIs(e.args[0], m.i[1])
+        self.assertIs(e.args[1], m.i[0])
+        self.assertIs(e.args[2], m.seq)
+
+        self.assertEqual(str(e), "before_in(i[1], i[0], seq)")
+
+    def test_predecessor_in_sequence(self):
+        m = self.get_model()
+        m.c = LogicalConstraint(expr=predecessor_to(m.i[0], m.i[1], m.seq))
+        e = m.c.expr
+
+        self.assertIsInstance(e, PredecessorToExpression)
+        self.assertEqual(e.nargs(), 3)
+        self.assertEqual(len(e.args), 3)
+        self.assertIs(e.args[0], m.i[0])
+        self.assertIs(e.args[1], m.i[1])
+        self.assertIs(e.args[2], m.seq)
+
+        self.assertEqual(str(e), "predecessor_to(i[0], i[1], seq)")
+
+
+class TestHierarchicalSchedulingExpressions(unittest.TestCase):
+    def make_model(self):
+        m = ConcreteModel()
+
+        def start_rule(m, i):
+            return 2 * i
+
+        def length_rule(m, i):
+            return i
+
+        m.iv = IntervalVar(
+            [1, 2, 3], start=start_rule, length=length_rule, optional=True
+        )
+        m.whole_enchilada = IntervalVar()
+
+        return m
+
+    def check_span_expression(self, m, e):
+        self.assertIsInstance(e, SpanExpression)
+        self.assertEqual(e.nargs(), 4)
+        self.assertEqual(len(e.args), 4)
+        self.assertIs(e.args[0], m.whole_enchilada)
+        for i in [1, 2, 3]:
+            self.assertIs(e.args[i], m.iv[i])
+
+        self.assertEqual(str(e), "whole_enchilada.spans(iv[1], iv[2], iv[3])")
+
+    def test_spans(self):
+        m = self.make_model()
+        e = spans(m.whole_enchilada, [m.iv[i] for i in [1, 2, 3]])
+        self.check_span_expression(m, e)
+
+    def test_spans_method(self):
+        m = self.make_model()
+        e = m.whole_enchilada.spans(m.iv[i] for i in [1, 2, 3])
+        self.check_span_expression(m, e)
+
+    def test_alternative(self):
+        m = self.make_model()
+        e = alternative(m.whole_enchilada, [m.iv[i] for i in [1, 2, 3]])
+
+        self.assertIsInstance(e, AlternativeExpression)
+        self.assertEqual(e.nargs(), 4)
+        self.assertEqual(len(e.args), 4)
+        self.assertIs(e.args[0], m.whole_enchilada)
+        for i in [1, 2, 3]:
+            self.assertIs(e.args[i], m.iv[i])
+
+        self.assertEqual(str(e), "alternative(whole_enchilada, [iv[1], iv[2], iv[3]])")
+
+    def test_synchronize(self):
+        m = self.make_model()
+        e = synchronize(m.whole_enchilada, [m.iv[i] for i in [1, 2, 3]])
+
+        self.assertIsInstance(e, SynchronizeExpression)
+        self.assertEqual(e.nargs(), 4)
+        self.assertEqual(len(e.args), 4)
+        self.assertIs(e.args[0], m.whole_enchilada)
+        for i in [1, 2, 3]:
+            self.assertIs(e.args[i], m.iv[i])
+
+        self.assertEqual(str(e), "synchronize(whole_enchilada, [iv[1], iv[2], iv[3]])")
diff --git a/pyomo/contrib/cp/tests/test_sequence_var.py b/pyomo/contrib/cp/tests/test_sequence_var.py
new file mode 100644
index 00000000000..c1e205c6326
--- /dev/null
+++ b/pyomo/contrib/cp/tests/test_sequence_var.py
@@ -0,0 +1,158 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+from io import StringIO
+import pyomo.common.unittest as unittest
+from pyomo.contrib.cp.interval_var import IntervalVar
+from pyomo.contrib.cp.sequence_var import SequenceVar, IndexedSequenceVar
+from pyomo.environ import ConcreteModel, Set
+
+
+class TestScalarSequenceVar(unittest.TestCase):
+    def test_initialize_with_no_data(self):
+        m = ConcreteModel()
+        m.i = SequenceVar()
+
+        self.assertIsInstance(m.i, SequenceVar)
+        self.assertIsInstance(m.i.interval_vars, list)
+        self.assertEqual(len(m.i.interval_vars), 0)
+
+        m.iv1 = IntervalVar()
+        m.iv2 = IntervalVar()
+        m.i.set_value(expr=[m.iv1, m.iv2])
+
+        self.assertIsInstance(m.i.interval_vars, list)
+        self.assertEqual(len(m.i.interval_vars), 2)
+        self.assertIs(m.i.interval_vars[0], m.iv1)
+        self.assertIs(m.i.interval_vars[1], m.iv2)
+
+    def get_model(self):
+        m = ConcreteModel()
+        m.S = Set(initialize=range(3))
+        m.i = IntervalVar(m.S, start=(0, 5))
+        m.seq = SequenceVar(expr=[m.i[j] for j in m.S])
+
+        return m
+
+    def test_initialize_with_expr(self):
+        m = self.get_model()
+        self.assertEqual(len(m.seq.interval_vars), 3)
+        for j in m.S:
+            self.assertIs(m.seq.interval_vars[j], m.i[j])
+
+    def test_pprint(self):
+        m = self.get_model()
+        buf = StringIO()
+        m.seq.pprint(ostream=buf)
+        self.assertEqual(
+            buf.getvalue().strip(),
+            """
+seq : Size=1, Index=None
+    Key  : IntervalVars
+    None : [i[0], i[1], i[2]]
+            """.strip(),
+        )
+
+    def test_interval_vars_not_a_list(self):
+        m = self.get_model()
+
+        with self.assertRaisesRegex(
+            ValueError,
+            "'expr' for SequenceVar must be a list of IntervalVars. "
+            "Encountered type '<class 'int'>' constructing 'seq2'",
+        ):
+            m.seq2 = SequenceVar(expr=1)
+
+    def test_interval_vars_list_includes_things_that_are_not_interval_vars(self):
+        m = self.get_model()
+
+        with self.assertRaisesRegex(
+            ValueError,
+            "The SequenceVar 'expr' argument must be a list of "
+            "IntervalVars. The 'expr' for SequenceVar 'seq2' included "
+            "an object of type '<class 'int'>'",
+        ):
+            m.seq2 = SequenceVar(expr=m.i)
+
+
+class TestIndexedSequenceVar(unittest.TestCase):
+    def test_initialize_with_not_data(self):
+        m = ConcreteModel()
+        m.i = SequenceVar([1, 2])
+
+        self.assertIsInstance(m.i, IndexedSequenceVar)
+        for j in [1, 2]:
+            self.assertIsInstance(m.i[j].interval_vars, list)
+            self.assertEqual(len(m.i[j].interval_vars), 0)
+
+        m.iv = IntervalVar()
+        m.iv2 = IntervalVar([0, 1])
+        m.i[2] = [m.iv] + [m.iv2[i] for i in [0, 1]]
+
+        self.assertEqual(len(m.i[2].interval_vars), 3)
+        self.assertEqual(len(m.i[1].interval_vars), 0)
+        self.assertIs(m.i[2].interval_vars[0], m.iv)
+        for i in [0, 1]:
+            self.assertIs(m.i[2].interval_vars[i + 1], m.iv2[i])
+
+    def make_model(self):
+        m = ConcreteModel()
+        m.alphabetic = Set(initialize=['a', 'b'])
+        m.numeric = Set(initialize=[1, 2])
+        m.i = IntervalVar(m.alphabetic, m.numeric)
+
+        def the_rule(m, j):
+            return [m.i[j, k] for k in m.numeric]
+
+        m.seq = SequenceVar(m.alphabetic, rule=the_rule)
+
+        return m
+
+    def test_initialize_with_rule(self):
+        m = self.make_model()
+
+        self.assertIsInstance(m.seq, IndexedSequenceVar)
+        self.assertEqual(len(m.seq), 2)
+        for j in m.alphabetic:
+            self.assertTrue(j in m.seq)
+            self.assertEqual(len(m.seq[j].interval_vars), 2)
+            for k in m.numeric:
+                self.assertIs(m.seq[j].interval_vars[k - 1], m.i[j, k])
+
+    def test_pprint(self):
+        m = self.make_model()
+        m.seq.pprint()
+
+        buf = StringIO()
+        m.seq.pprint(ostream=buf)
+        self.assertEqual(
+            buf.getvalue().strip(),
+            """
+seq : Size=2, Index=alphabetic
+    Key : IntervalVars
+      a : [i[a,1], i[a,2]]
+      b : [i[b,1], i[b,2]]""".strip(),
+        )
+
+    def test_multidimensional_index(self):
+        m = self.make_model()
+
+        @m.SequenceVar(m.alphabetic, m.numeric)
+        def s(m, i, j):
+            return [m.i[i, j]]
+
+        self.assertIsInstance(m.s, IndexedSequenceVar)
+        self.assertEqual(len(m.s), 4)
+        for i in m.alphabetic:
+            for j in m.numeric:
+                self.assertTrue((i, j) in m.s)
+                self.assertEqual(len(m.s[i, j].interval_vars), 1)
+                self.assertIs(m.s[i, j].interval_vars[0], m.i[i, j])
diff --git a/pyomo/contrib/cp/tests/test_step_function_expressions.py b/pyomo/contrib/cp/tests/test_step_function_expressions.py
index 7212cc870d5..a7b30c1d4e6 100644
--- a/pyomo/contrib/cp/tests/test_step_function_expressions.py
+++ b/pyomo/contrib/cp/tests/test_step_function_expressions.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/cp/transform/__init__.py b/pyomo/contrib/cp/transform/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/cp/transform/__init__.py
+++ b/pyomo/contrib/cp/transform/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/cp/transform/logical_to_disjunctive_program.py b/pyomo/contrib/cp/transform/logical_to_disjunctive_program.py
index cd7681d4d87..7c5ef8d13c0 100644
--- a/pyomo/contrib/cp/transform/logical_to_disjunctive_program.py
+++ b/pyomo/contrib/cp/transform/logical_to_disjunctive_program.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -12,7 +12,6 @@
 from pyomo.contrib.cp.transform.logical_to_disjunctive_walker import (
     LogicalToDisjunctiveVisitor,
 )
-from pyomo.common.collections import ComponentMap
 from pyomo.common.modeling import unique_component_name
 from pyomo.common.config import ConfigDict, ConfigValue
 
@@ -26,7 +25,7 @@
     Transformation,
     NonNegativeIntegers,
 )
-from pyomo.core.base.block import _BlockData
+from pyomo.core.base.block import BlockData
 from pyomo.core.base import SortComponents
 from pyomo.core.util import target_list
 from pyomo.gdp import Disjunct, Disjunction
@@ -73,7 +72,7 @@ def _apply_to(self, model, **kwds):
         transBlocks = {}
         visitor = LogicalToDisjunctiveVisitor()
         for t in targets:
-            if t.ctype is Block or isinstance(t, _BlockData):
+            if t.ctype is Block or isinstance(t, BlockData):
                 self._transform_block(t, model, visitor, transBlocks)
             elif t.ctype is LogicalConstraint:
                 if t.is_indexed():
diff --git a/pyomo/contrib/cp/transform/logical_to_disjunctive_walker.py b/pyomo/contrib/cp/transform/logical_to_disjunctive_walker.py
index 624629d326d..09894b47090 100644
--- a/pyomo/contrib/cp/transform/logical_to_disjunctive_walker.py
+++ b/pyomo/contrib/cp/transform/logical_to_disjunctive_walker.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,14 +9,10 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-import collections
-
 from pyomo.common.collections import ComponentMap
 from pyomo.common.errors import MouseTrap
 from pyomo.core.expr.expr_common import ExpressionType
 from pyomo.core.expr.visitor import StreamBasedExpressionVisitor
-from pyomo.core.expr.numeric_expr import NumericExpression
-from pyomo.core.expr.relational_expr import RelationalExpression
 import pyomo.core.expr as EXPR
 from pyomo.core.base import (
     Binary,
@@ -27,9 +23,9 @@
     value,
 )
 import pyomo.core.base.boolean_var as BV
-from pyomo.core.base.expression import ScalarExpression, _GeneralExpressionData
-from pyomo.core.base.param import ScalarParam, _ParamData
-from pyomo.core.base.var import ScalarVar, _GeneralVarData
+from pyomo.core.base.expression import ScalarExpression, ExpressionData
+from pyomo.core.base.param import ScalarParam, ParamData
+from pyomo.core.base.var import ScalarVar, VarData
 from pyomo.gdp.disjunct import AutoLinkedBooleanVar, Disjunct, Disjunction
 
 
@@ -209,15 +205,15 @@ def _dispatch_atmost(visitor, node, *args):
 
 _before_child_dispatcher = {}
 _before_child_dispatcher[BV.ScalarBooleanVar] = _dispatch_boolean_var
-_before_child_dispatcher[BV._GeneralBooleanVarData] = _dispatch_boolean_var
+_before_child_dispatcher[BV.BooleanVarData] = _dispatch_boolean_var
 _before_child_dispatcher[AutoLinkedBooleanVar] = _dispatch_boolean_var
-_before_child_dispatcher[_ParamData] = _dispatch_param
+_before_child_dispatcher[ParamData] = _dispatch_param
 _before_child_dispatcher[ScalarParam] = _dispatch_param
 # for the moment, these are all just so we can get good error messages when we
 # don't handle them:
 _before_child_dispatcher[ScalarVar] = _dispatch_var
-_before_child_dispatcher[_GeneralVarData] = _dispatch_var
-_before_child_dispatcher[_GeneralExpressionData] = _dispatch_expression
+_before_child_dispatcher[VarData] = _dispatch_var
+_before_child_dispatcher[ExpressionData] = _dispatch_expression
 _before_child_dispatcher[ScalarExpression] = _dispatch_expression
 
 
diff --git a/pyomo/contrib/doe/__init__.py b/pyomo/contrib/doe/__init__.py
index e38b5dce1d9..e45aa3b44a3 100644
--- a/pyomo/contrib/doe/__init__.py
+++ b/pyomo/contrib/doe/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/doe/doe.py b/pyomo/contrib/doe/doe.py
index b451c431f21..a120add4200 100644
--- a/pyomo/contrib/doe/doe.py
+++ b/pyomo/contrib/doe/doe.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -38,6 +38,11 @@
 from pyomo.contrib.sensitivity_toolbox.sens import get_dsdp
 from pyomo.contrib.doe.scenario import ScenarioGenerator, FiniteDifferenceStep
 from pyomo.contrib.doe.result import FisherResults, GridSearchResult
+import collections.abc
+
+import inspect
+
+from pyomo.common import DeveloperError
 
 
 class CalculationMode(Enum):
@@ -68,6 +73,8 @@ def __init__(
         prior_FIM=None,
         discretize_model=None,
         args=None,
+        logger_level=logging.INFO,
+        only_compute_fim_lower=True,
     ):
         """
         This package enables model-based design of experiments analysis with Pyomo.
@@ -98,20 +105,48 @@ def __init__(
             A user-specified ``function`` that discretizes the model. Only use with Pyomo.DAE, default=None
         args:
             Additional arguments for the create_model function.
+        logger_level:
+            Specify the level of the logger. Change to logging.DEBUG for all messages.
+        only_compute_fim_lower:
+            If True, only the lower triangle of the FIM is computed. Default is True.
         """
 
         # parameters
+        if not isinstance(param_init, collections.abc.Mapping):
+            raise ValueError("param_init should be a dictionary.")
         self.param = param_init
         # design variable name
         self.design_name = design_vars.variable_names
         self.design_vars = design_vars
         self.create_model = create_model
+
+        # check if create model function conforms to the original
+        # Pyomo.DoE interface
+        model_option_arg = (
+            "model_option" in inspect.getfullargspec(self.create_model).args
+        )
+        mod_arg = "mod" in inspect.getfullargspec(self.create_model).args
+        if model_option_arg and mod_arg:
+            self._original_create_model_interface = True
+        else:
+            self._original_create_model_interface = False
+
+        if args is None:
+            args = {}
         self.args = args
 
         # create the measurement information object
         self.measurement_vars = measurement_vars
         self.measure_name = self.measurement_vars.variable_names
 
+        if (
+            self.measurement_vars.variable_names is None
+            or not self.measurement_vars.variable_names
+        ):
+            raise ValueError(
+                "There are no measurement variables. Check for a modeling mistake."
+            )
+
         # check if user-defined solver is given
         if solver:
             self.solver = solver
@@ -131,17 +166,19 @@ def __init__(
 
         # if print statements
         self.logger = logging.getLogger(__name__)
-        self.logger.setLevel(level=logging.INFO)
+        self.logger.setLevel(level=logger_level)
+
+        self.only_compute_fim_lower = only_compute_fim_lower
 
     def _check_inputs(self):
         """
         Check if the prior FIM is N*N matrix, where N is the number of parameter
         """
-        if type(self.prior_FIM) != type(None):
+        if self.prior_FIM is not None:
             if np.shape(self.prior_FIM)[0] != np.shape(self.prior_FIM)[1]:
-                raise ValueError('Found wrong prior information matrix shape.')
+                raise ValueError("Found wrong prior information matrix shape.")
             elif np.shape(self.prior_FIM)[0] != len(self.param):
-                raise ValueError('Found wrong prior information matrix shape.')
+                raise ValueError("Found wrong prior information matrix shape.")
 
     def stochastic_program(
         self,
@@ -226,6 +263,7 @@ def stochastic_program(
         # FIM = Jacobian.T@Jacobian, the FIM is scaled by squared value the Jacobian is scaled
         self.fim_scale_constant_value = self.scale_constant_value**2
 
+        # Start timer
         sp_timer = TicTocTimer()
         sp_timer.tic(msg=None)
 
@@ -236,14 +274,17 @@ def stochastic_program(
         m, analysis_square = self._compute_stochastic_program(m, optimize_opt)
 
         if self.optimize:
+            # If set to optimize, solve the optimization problem (with degrees of freedom)
             analysis_optimize = self._optimize_stochastic_program(m)
             dT = sp_timer.toc(msg=None)
-            self.logger.info("elapsed time: %0.1f" % dT)
+            self.logger.info("elapsed time: %0.1f seconds" % dT)
+            # Return both square problem and optimization problem results
             return analysis_square, analysis_optimize
 
         else:
             dT = sp_timer.toc(msg=None)
-            self.logger.info("elapsed time: %0.1f" % dT)
+            self.logger.info("elapsed time: %0.1f seconds" % dT)
+            # Return only square problem results
             return analysis_square
 
     def _compute_stochastic_program(self, m, optimize_option):
@@ -314,6 +355,7 @@ def compute_FIM(
         extract_single_model=None,
         formula="central",
         step=0.001,
+        only_compute_fim_lower=False,
     ):
         """
         This function calculates the Fisher information matrix (FIM) using sensitivity information obtained
@@ -387,7 +429,7 @@ def compute_FIM(
             FIM_analysis = self._direct_kaug()
 
         dT = square_timer.toc(msg=None)
-        self.logger.info("elapsed time: %0.1f" % dT)
+        self.logger.info("elapsed time: %0.1f seconds" % dT)
 
         return FIM_analysis
 
@@ -396,7 +438,7 @@ def _sequential_finite(self, read_output, extract_single_model, store_output):
 
         # if measurements are provided
         if read_output:
-            with open(read_output, 'rb') as f:
+            with open(read_output, "rb") as f:
                 output_record = pickle.load(f)
                 f.close()
             jac = self._finite_calculation(output_record)
@@ -408,11 +450,21 @@ def _sequential_finite(self, read_output, extract_single_model, store_output):
             # dict for storing model outputs
             output_record = {}
 
+            # Deactivate any existing objective functions
+            for obj in mod.component_objects(pyo.Objective):
+                obj.deactivate()
+
+            # add zero (dummy/placeholder) objective function
+            mod.Obj = pyo.Objective(expr=0, sense=pyo.minimize)
+
             # solve model
             square_result = self._solve_doe(mod, fix=True)
 
+            # save model from optional post processing function
+            self._square_model_from_compute_FIM = mod
+
             if extract_single_model:
-                mod_name = store_output + '.csv'
+                mod_name = store_output + ".csv"
                 dataframe = extract_single_model(mod, square_result)
                 dataframe.to_csv(mod_name)
 
@@ -434,10 +486,10 @@ def _sequential_finite(self, read_output, extract_single_model, store_output):
 
                 output_record[s] = output_iter
 
-                output_record['design'] = self.design_values
+                output_record["design"] = self.design_values
 
                 if store_output:
-                    f = open(store_output, 'wb')
+                    f = open(store_output, "wb")
                     pickle.dump(output_record, f)
                     f.close()
 
@@ -472,13 +524,20 @@ def _sequential_finite(self, read_output, extract_single_model, store_output):
 
     def _direct_kaug(self):
         # create model
-        mod = self.create_model(model_option=ModelOptionLib.parmest)
+        if self._original_create_model_interface:
+            mod = self.create_model(model_option=ModelOptionLib.parmest, **self.args)
+        else:
+            mod = self.create_model(**self.args)
 
         # discretize if needed
-        if self.discretize_model:
+        if self.discretize_model is not None:
             mod = self.discretize_model(mod, block=False)
 
-        # add objective function
+        # Deactivate any existing objective functions
+        for obj in mod.component_objects(pyo.Objective):
+            obj.deactivate()
+
+        # add zero (dummy/placeholder) objective function
         mod.Obj = pyo.Objective(expr=0, sense=pyo.minimize)
 
         # set ub and lb to parameters
@@ -493,6 +552,10 @@ def _direct_kaug(self):
 
         # call k_aug get_dsdp function
         square_result = self._solve_doe(mod, fix=True)
+
+        # save model from optional post processing function
+        self._square_model_from_compute_FIM = mod
+
         dsdp_re, col = get_dsdp(
             mod, list(self.param.keys()), self.param, tee=self.tee_opt
         )
@@ -515,7 +578,7 @@ def _direct_kaug(self):
                 dsdp_extract.append(dsdp_array[kaug_no])
             except:
                 # k_aug does not provide value for fixed variables
-                self.logger.debug('The variable is fixed:  %s', mname)
+                self.logger.debug("The variable is fixed:  %s", mname)
                 # produce the sensitivity for fixed variables
                 zero_sens = np.zeros(len(self.param))
                 # for fixed variables, the sensitivity are a zero vector
@@ -581,29 +644,93 @@ def _create_block(self):
         self.eps_abs = self.scenario_data.eps_abs
         self.scena_gen = scena_gen
 
-        # Create a global model
-        mod = pyo.ConcreteModel()
+        # Determine if create_model takes theta as an optional input
+        pass_theta_to_initialize = (
+            "theta" in inspect.getfullargspec(self.create_model).args
+        )
+
+        # Allow user to self-define complex design variables
+        if self._original_create_model_interface:
+
+            # Create a global model
+            mod = pyo.ConcreteModel()
+
+            if pass_theta_to_initialize:
+                # Add model on block with theta values
+                self.create_model(
+                    mod=mod,
+                    model_option=ModelOptionLib.stage1,
+                    theta=self.param,
+                    **self.args,
+                )
+            else:
+                # Add model on block without theta values
+                self.create_model(
+                    mod=mod, model_option=ModelOptionLib.stage1, **self.args
+                )
+
+        else:
+            # Create a global model
+            mod = self.create_model(**self.args)
 
         # Set for block/scenarios
         mod.scenario = pyo.Set(initialize=self.scenario_data.scenario_indices)
 
-        # Allow user to self-define complex design variables
-        self.create_model(mod=mod, model_option=ModelOptionLib.stage1)
+        # Fix parameter values in the copy of the stage1 model (if they exist)
+        for par in self.param:
+            cuid = pyo.ComponentUID(par)
+            var = cuid.find_component_on(mod)
+            if var is not None:
+                # Fix the parameter value
+                # Otherwise, the parameter does not exist on the stage 1 model
+                var.fix(self.param[par])
 
         def block_build(b, s):
             # create block scenarios
-            self.create_model(mod=b, model_option=ModelOptionLib.stage2)
+            # idea: check if create_model takes theta as an optional input, if so, pass parameter values to create_model
+
+            if self._original_create_model_interface:
+                if pass_theta_to_initialize:
+                    # Grab the values of theta for this scenario/block
+                    theta_initialize = self.scenario_data.scenario[s]
+                    # Add model on block with theta values
+                    self.create_model(
+                        mod=b,
+                        model_option=ModelOptionLib.stage2,
+                        theta=theta_initialize,
+                        **self.args,
+                    )
+                else:
+                    # Otherwise add model on block without theta values
+                    self.create_model(
+                        mod=b, model_option=ModelOptionLib.stage2, **self.args
+                    )
+
+                # save block in a temporary variable
+                mod_ = b
+            else:
+                # Add model on block
+                if pass_theta_to_initialize:
+                    # Grab the values of theta for this scenario/block
+                    theta_initialize = self.scenario_data.scenario[s]
+                    mod_ = self.create_model(theta=theta_initialize, **self.args)
+                else:
+                    mod_ = self.create_model(**self.args)
 
             # fix parameter values to perturbed values
             for par in self.param:
                 cuid = pyo.ComponentUID(par)
-                var = cuid.find_component_on(b)
+                var = cuid.find_component_on(mod_)
                 var.fix(self.scenario_data.scenario[s][par])
 
+            if not self._original_create_model_interface:
+                # for the "new"/"slim" interface, we need to add the block to the model
+                return mod_
+
         mod.block = pyo.Block(mod.scenario, rule=block_build)
 
         # discretize the model
-        if self.discretize_model:
+        if self.discretize_model is not None:
             mod = self.discretize_model(mod)
 
         # force design variables in blocks to be equal to global design values
@@ -618,6 +745,13 @@ def fix1(mod, s):
             con_name = "con" + name
             mod.add_component(con_name, pyo.Constraint(mod.scenario, expr=fix1))
 
+            # Add user-defined design variable bounds
+            cuid = pyo.ComponentUID(name)
+            design_var_global = cuid.find_component_on(mod)
+            # Set the lower and upper bounds of the design variables
+            design_var_global.setlb(self.design_vars.lower_bounds[name])
+            design_var_global.setub(self.design_vars.upper_bounds[name])
+
         return mod
 
     def _finite_calculation(self, output_record):
@@ -693,6 +827,7 @@ def run_grid_search(
         store_optimality_as_csv=None,
         formula="central",
         step=0.001,
+        post_processing_function=None,
     ):
         """
         Enumerate through full grid search for any number of design variables;
@@ -734,6 +869,10 @@ def run_grid_search(
             This option is only used for CalculationMode.sequential_finite.
         step:
             Sensitivity perturbation step size, a fraction between [0,1]. default is 0.001
+        post_processing_function:
+            An optional function that executes after each solve of the grid search.
+            The function should take one input: the Pyomo model. This could be a plotting function.
+            Default is None.
 
         Returns
         -------
@@ -772,20 +911,31 @@ def run_grid_search(
             # generate the design variable dictionary needed for running compute_FIM
             # first copy value from design_values
             design_iter = self.design_vars.variable_names_value.copy()
+
+            # convert to a list and cache
+            list_design_set_iter = list(design_set_iter)
+
             # update the controlled value of certain time points for certain design variables
             for i, names in enumerate(design_dimension_names):
-                # if the element is a list, all design variables in this list share the same values
-                if type(names) is list or type(names) is tuple:
+                if isinstance(names, str):
+                    # if 'names' is simply a string, copy the new value
+                    design_iter[names] = list_design_set_iter[i]
+                elif isinstance(names, collections.abc.Sequence):
+                    # if the element is a list, all design variables in this list share the same values
                     for n in names:
-                        design_iter[n] = list(design_set_iter)[i]
+                        design_iter[n] = list_design_set_iter[i]
                 else:
-                    design_iter[names] = list(design_set_iter)[i]
+                    # otherwise just copy the value
+                    # design_iter[names] = list(design_set_iter)[i]
+                    raise NotImplementedError(
+                        "You should not see this error message. Please report it to the Pyomo.DoE developers."
+                    )
 
             self.design_vars.variable_names_value = design_iter
             iter_timer = TicTocTimer()
-            self.logger.info('=======Iteration Number: %s =====', count + 1)
+            self.logger.info("=======Iteration Number: %s =====", count + 1)
             self.logger.debug(
-                'Design variable values of this iteration: %s', design_iter
+                "Design variable values of this iteration: %s", design_iter
             )
             iter_timer.tic(msg=None)
             # generate store name
@@ -794,7 +944,7 @@ def run_grid_search(
             else:
                 store_output_name = store_name + str(count)
 
-            if read_name:
+            if read_name is not None:
                 read_input_name = read_name + str(count)
             else:
                 read_input_name = None
@@ -821,23 +971,31 @@ def run_grid_search(
                 time_set.append(iter_t)
 
                 # give run information at each iteration
-                self.logger.info('This is run %s out of %s.', count, total_count)
-                self.logger.info('The code has run  %s seconds.', sum(time_set))
+                self.logger.info("This is run %s out of %s.", count, total_count)
                 self.logger.info(
-                    'Estimated remaining time:  %s seconds',
-                    (sum(time_set) / (count + 1) * (total_count - count - 1)),
+                    "The code has run  %s seconds.", round(sum(time_set), 2)
                 )
+                self.logger.info(
+                    "Estimated remaining time:  %s seconds",
+                    round(
+                        sum(time_set) / (count) * (total_count - count), 2
+                    ),  # need to check this math... it gives a negative number for the final count
+                )
+
+                if post_processing_function is not None:
+                    # Call the post processing function
+                    post_processing_function(self._square_model_from_compute_FIM)
 
                 # the combined result object are organized as a dictionary, keys are a tuple of the design variable values, values are a result object
                 result_combine[tuple(design_set_iter)] = result_iter
 
             except:
                 self.logger.warning(
-                    ':::::::::::Warning: Cannot converge this run.::::::::::::'
+                    ":::::::::::Warning: Cannot converge this run.::::::::::::"
                 )
                 count += 1
                 failed_count += 1
-                self.logger.warning('failed count:', failed_count)
+                self.logger.warning("failed count:", failed_count)
                 result_combine[tuple(design_set_iter)] = None
 
         # For user's access
@@ -851,7 +1009,7 @@ def run_grid_search(
             store_optimality_name=store_optimality_as_csv,
         )
 
-        self.logger.info('Overall wall clock time [s]:  %s', sum(time_set))
+        self.logger.info("Overall wall clock time [s]:  %s", sum(time_set))
 
         return figure_draw_object
 
@@ -867,6 +1025,18 @@ def _create_doe_model(self, no_obj=True):
         -------
         model: the DOE model
         """
+
+        # Developer recommendation: use the Cholesky decomposition for D-optimality
+        # The explicit formula is available for benchmarking purposes and is NOT recommended
+        if (
+            self.only_compute_fim_lower
+            and self.objective_option == ObjectiveLib.det
+            and not self.Cholesky_option
+        ):
+            raise ValueError(
+                "Cannot compute determinant with explicit formula if only_compute_fim_lower is True."
+            )
+
         model = self._create_block()
 
         # variables for jacobian and FIM
@@ -879,20 +1049,46 @@ def identity_matrix(m, i, j):
             else:
                 return 0
 
+        ### Initialize the Jacobian if provided by the user
+
+        # If the user provides an initial Jacobian, convert it to a dictionary
+        if self.jac_initial is not None:
+            dict_jac_initialize = {}
+            for i, bu in enumerate(model.regression_parameters):
+                for j, un in enumerate(model.measured_variables):
+                    if isinstance(self.jac_initial, dict):
+                        # Jacobian is a dictionary of arrays or lists where the key is the regression parameter name
+                        dict_jac_initialize[(bu, un)] = self.jac_initial[bu][j]
+                    elif isinstance(self.jac_initial, np.ndarray):
+                        # Jacobian is a numpy array, rows are regression parameters, columns are measured variables
+                        dict_jac_initialize[(bu, un)] = self.jac_initial[i][j]
+
+        # Initialize the Jacobian matrix
+        def initialize_jac(m, i, j):
+            # If provided by the user, use the values now stored in the dictionary
+            if self.jac_initial is not None:
+                return dict_jac_initialize[(i, j)]
+            # Otherwise initialize to 0.1 (which is an arbitrary non-zero value)
+            else:
+                return 0.1
+
         model.sensitivity_jacobian = pyo.Var(
-            model.regression_parameters, model.measured_variables, initialize=0.1
+            model.regression_parameters,
+            model.measured_variables,
+            initialize=initialize_jac,
         )
 
-        if self.fim_initial:
-            dict_fim_initialize = {}
-            for i, bu in enumerate(model.regression_parameters):
-                for j, un in enumerate(model.regression_parameters):
-                    dict_fim_initialize[(bu, un)] = self.fim_initial[i][j]
+        if self.fim_initial is not None:
+            dict_fim_initialize = {
+                (bu, un): self.fim_initial[i][j]
+                for i, bu in enumerate(model.regression_parameters)
+                for j, un in enumerate(model.regression_parameters)
+            }
 
         def initialize_fim(m, j, d):
             return dict_fim_initialize[(j, d)]
 
-        if self.fim_initial:
+        if self.fim_initial is not None:
             model.fim = pyo.Var(
                 model.regression_parameters,
                 model.regression_parameters,
@@ -905,22 +1101,24 @@ def initialize_fim(m, j, d):
                 initialize=identity_matrix,
             )
 
-        # move the L matrix initial point to a dictionary
-        if type(self.L_initial) != type(None):
-            dict_cho = {}
-            for i, bu in enumerate(model.regression_parameters):
-                for j, un in enumerate(model.regression_parameters):
-                    dict_cho[(bu, un)] = self.L_initial[i][j]
+        # if cholesky, define L elements as variables
+        if self.Cholesky_option and self.objective_option == ObjectiveLib.det:
 
-        # use the L dictionary to initialize L matrix
-        def init_cho(m, i, j):
-            return dict_cho[(i, j)]
+            # move the L matrix initial point to a dictionary
+            if self.L_initial is not None:
+                dict_cho = {
+                    (bu, un): self.L_initial[i][j]
+                    for i, bu in enumerate(model.regression_parameters)
+                    for j, un in enumerate(model.regression_parameters)
+                }
+
+            # use the L dictionary to initialize L matrix
+            def init_cho(m, i, j):
+                return dict_cho[(i, j)]
 
-        # if cholesky, define L elements as variables
-        if self.Cholesky_option:
             # Define elements of Cholesky decomposition matrix as Pyomo variables and either
             # Initialize with L in L_initial
-            if type(self.L_initial) != type(None):
+            if self.L_initial is not None:
                 model.L_ele = pyo.Var(
                     model.regression_parameters,
                     model.regression_parameters,
@@ -971,10 +1169,11 @@ def jacobian_rule(m, p, n):
 
         # A constraint to calculate elements in Hessian matrix
         # transfer prior FIM to be Expressions
-        fim_initial_dict = {}
-        for i, bu in enumerate(model.regression_parameters):
-            for j, un in enumerate(model.regression_parameters):
-                fim_initial_dict[(bu, un)] = self.prior_FIM[i][j]
+        fim_initial_dict = {
+            (bu, un): self.prior_FIM[i][j]
+            for i, bu in enumerate(model.regression_parameters)
+            for j, un in enumerate(model.regression_parameters)
+        }
 
         def read_prior(m, i, j):
             return fim_initial_dict[(i, j)]
@@ -983,23 +1182,31 @@ def read_prior(m, i, j):
             model.regression_parameters, model.regression_parameters, rule=read_prior
         )
 
+        # The off-diagonal elements are symmetric, thus only half of the elements need to be calculated
         def fim_rule(m, p, q):
             """
             m: Pyomo model
             p: parameter
             q: parameter
             """
-            return (
-                m.fim[p, q]
-                == sum(
-                    1
-                    / self.measurement_vars.variance[n]
-                    * m.sensitivity_jacobian[p, n]
-                    * m.sensitivity_jacobian[q, n]
-                    for n in model.measured_variables
+
+            if p > q:
+                if self.only_compute_fim_lower:
+                    return pyo.Constraint.Skip
+                else:
+                    return m.fim[p, q] == m.fim[q, p]
+            else:
+                return (
+                    m.fim[p, q]
+                    == sum(
+                        1
+                        / self.measurement_vars.variance[n]
+                        * m.sensitivity_jacobian[p, n]
+                        * m.sensitivity_jacobian[q, n]
+                        for n in model.measured_variables
+                    )
+                    + m.priorFIM[p, q] * self.fim_scale_constant_value
                 )
-                + m.priorFIM[p, q] * self.fim_scale_constant_value
-            )
 
         model.jacobian_constraint = pyo.Constraint(
             model.regression_parameters, model.measured_variables, rule=jacobian_rule
@@ -1008,9 +1215,55 @@ def fim_rule(m, p, q):
             model.regression_parameters, model.regression_parameters, rule=fim_rule
         )
 
+        if self.only_compute_fim_lower:
+            # Fix the upper half of the FIM matrix elements to be 0.0.
+            # This eliminates extra variables and ensures the expected number of
+            # degrees of freedom in the optimization problem.
+            for p in model.regression_parameters:
+                for q in model.regression_parameters:
+                    if p > q:
+                        model.fim[p, q].fix(0.0)
+
         return model
 
     def _add_objective(self, m):
+
+        small_number = 1e-10
+
+        # Assemble the FIM matrix. This is helpful for initialization!
+        #
+        # Suggestion from JS: "It might be more efficient to form the NP array in one shot
+        # (from a list or using fromiter), and then reshaping to the 2-D matrix"
+        #
+        fim = np.zeros((len(self.param), len(self.param)))
+        for i, bu in enumerate(m.regression_parameters):
+            for j, un in enumerate(m.regression_parameters):
+                # Copy value from Pyomo model into numpy array
+                fim[i][j] = m.fim[bu, un].value
+
+                # Set lower bound to ensure diagonal elements are (almost) non-negative
+                # if i == j:
+                #     m.fim[bu, un].setlb(-small_number)
+
+        ### Initialize the Cholesky decomposition matrix
+        if self.Cholesky_option and self.objective_option == ObjectiveLib.det:
+
+            # Calculate the eigenvalues of the FIM matrix
+            eig = np.linalg.eigvals(fim)
+
+            # If the smallest eigenvalue is (practically) negative, add a diagonal matrix to make it positive definite
+            small_number = 1e-10
+            if min(eig) < small_number:
+                fim = fim + np.eye(len(self.param)) * (small_number - min(eig))
+
+            # Compute the Cholesky decomposition of the FIM matrix
+            L = np.linalg.cholesky(fim)
+
+            # Initialize the Cholesky matrix
+            for i, c in enumerate(m.regression_parameters):
+                for j, d in enumerate(m.regression_parameters):
+                    m.L_ele[c, d].value = L[i, j]
+
         def cholesky_imp(m, c, d):
             """
             Calculate Cholesky L matrix using algebraic constraints
@@ -1034,7 +1287,7 @@ def trace_calc(m):
 
         def det_general(m):
             r"""Calculate determinant. Can be applied to FIM of any size.
-            det(A) = sum_{\sigma \in \S_n} (sgn(\sigma) * \Prod_{i=1}^n a_{i,\sigma_i})
+            det(A) = \sum_{\sigma in \S_n} (sgn(\sigma) * \Prod_{i=1}^n a_{i,\sigma_i})
             Use permutation() to get permutations, sgn() to get signature
             """
             r_list = list(range(len(m.regression_parameters)))
@@ -1064,24 +1317,36 @@ def det_general(m):
             )
             return m.det == det_perm
 
-        if self.Cholesky_option:
+        if self.Cholesky_option and self.objective_option == ObjectiveLib.det:
             m.cholesky_cons = pyo.Constraint(
                 m.regression_parameters, m.regression_parameters, rule=cholesky_imp
             )
             m.Obj = pyo.Objective(
-                expr=2 * sum(pyo.log(m.L_ele[j, j]) for j in m.regression_parameters),
+                expr=2 * sum(pyo.log10(m.L_ele[j, j]) for j in m.regression_parameters),
                 sense=pyo.maximize,
             )
-        # if not cholesky but determinant, calculating det and evaluate the OBJ with det
+
         elif self.objective_option == ObjectiveLib.det:
+            # if not cholesky but determinant, calculating det and evaluate the OBJ with det
+            m.det = pyo.Var(initialize=np.linalg.det(fim), bounds=(small_number, None))
             m.det_rule = pyo.Constraint(rule=det_general)
-            m.Obj = pyo.Objective(expr=pyo.log(m.det), sense=pyo.maximize)
-        # if not determinant or cholesky, calculating the OBJ with trace
+            m.Obj = pyo.Objective(expr=pyo.log10(m.det), sense=pyo.maximize)
+
         elif self.objective_option == ObjectiveLib.trace:
+            # if not determinant or cholesky, calculating the OBJ with trace
+            m.trace = pyo.Var(initialize=np.trace(fim), bounds=(small_number, None))
             m.trace_rule = pyo.Constraint(rule=trace_calc)
-            m.Obj = pyo.Objective(expr=pyo.log(m.trace), sense=pyo.maximize)
+            m.Obj = pyo.Objective(expr=pyo.log10(m.trace), sense=pyo.maximize)
+            # m.Obj = pyo.Objective(expr=m.trace, sense=pyo.maximize)
+
         elif self.objective_option == ObjectiveLib.zero:
+            # add dummy objective function
             m.Obj = pyo.Objective(expr=0)
+        else:
+            # something went wrong!
+            raise DeveloperError(
+                "Objective option not recognized. Please contact the developers as you should not see this error."
+            )
 
         return m
 
@@ -1101,30 +1366,36 @@ def _fix_design(self, m, design_val, fix_opt=True, optimize_option=None):
         m: model
         """
         for name in self.design_name:
+            # Loop over design variables
+            # Get Pyomo variable object
             cuid = pyo.ComponentUID(name)
             var = cuid.find_component_on(m)
             if fix_opt:
+                # If fix_opt is True, fix the design variable
                 var.fix(design_val[name])
             else:
+                # Otherwise check optimize_option
                 if optimize_option is None:
+                    # If optimize_option is None, unfix all design variables
                     var.unfix()
                 else:
+                    # Otherwise, unfix only the design variables listed in optimize_option with value True
                     if optimize_option[name]:
                         var.unfix()
         return m
 
     def _get_default_ipopt_solver(self):
         """Default solver"""
-        solver = SolverFactory('ipopt')
-        solver.options['linear_solver'] = 'ma57'
-        solver.options['halt_on_ampl_error'] = 'yes'
-        solver.options['max_iter'] = 3000
+        solver = SolverFactory("ipopt")
+        solver.options["linear_solver"] = "ma57"
+        solver.options["halt_on_ampl_error"] = "yes"
+        solver.options["max_iter"] = 3000
         return solver
 
     def _solve_doe(self, m, fix=False, opt_option=None):
         """Solve DOE model.
         If it's a square problem, fix design variable and solve.
-        Else, fix design variable and solve square problem firstly, then unfix them and solve the optimization problem
+        Else, fix design variable and solve square problem first, then unfix them and solve the optimization problem
 
         Parameters
         ----------
@@ -1138,7 +1409,10 @@ def _solve_doe(self, m, fix=False, opt_option=None):
         -------
         solver_results: solver results
         """
-        ### Solve square problem
+        # if fix = False, solve the optimization problem
+        # if fix = True, solve the square problem
+
+        # either fix or unfix the design variables
         mod = self._fix_design(
             m, self.design_values, fix_opt=fix, optimize_option=opt_option
         )
diff --git a/pyomo/contrib/doe/examples/__init__.py b/pyomo/contrib/doe/examples/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/doe/examples/__init__.py
+++ b/pyomo/contrib/doe/examples/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/doe/examples/fim_doe_tutorial.ipynb b/pyomo/contrib/doe/examples/fim_doe_tutorial.ipynb
index 12d5a610db4..36ec42fbe49 100644
--- a/pyomo/contrib/doe/examples/fim_doe_tutorial.ipynb
+++ b/pyomo/contrib/doe/examples/fim_doe_tutorial.ipynb
@@ -87,6 +87,7 @@
     "if \"google.colab\" in sys.modules:\n",
     "    !wget \"https://raw.githubusercontent.com/IDAES/idaes-pse/main/scripts/colab_helper.py\"\n",
     "    import colab_helper\n",
+    "\n",
     "    colab_helper.install_idaes()\n",
     "    colab_helper.install_ipopt()\n",
     "\n",
diff --git a/pyomo/contrib/doe/examples/reactor_compute_FIM.py b/pyomo/contrib/doe/examples/reactor_compute_FIM.py
index c004ad36f00..108f5bd16a0 100644
--- a/pyomo/contrib/doe/examples/reactor_compute_FIM.py
+++ b/pyomo/contrib/doe/examples/reactor_compute_FIM.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/doe/examples/reactor_design.py b/pyomo/contrib/doe/examples/reactor_design.py
new file mode 100644
index 00000000000..67d6ff02fd2
--- /dev/null
+++ b/pyomo/contrib/doe/examples/reactor_design.py
@@ -0,0 +1,236 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#
+#  Pyomo.DoE was produced under the Department of Energy Carbon Capture Simulation
+#  Initiative (CCSI), and is copyright (c) 2022 by the software owners:
+#  TRIAD National Security, LLC., Lawrence Livermore National Security, LLC.,
+#  Lawrence Berkeley National Laboratory, Pacific Northwest National Laboratory,
+#  Battelle Memorial Institute, University of Notre Dame,
+#  The University of Pittsburgh, The University of Texas at Austin,
+#  University of Toledo, West Virginia University, et al. All rights reserved.
+#
+#  NOTICE. This Software was developed under funding from the
+#  U.S. Department of Energy and the U.S. Government consequently retains
+#  certain rights. As such, the U.S. Government has been granted for itself
+#  and others acting on its behalf a paid-up, nonexclusive, irrevocable,
+#  worldwide license in the Software to reproduce, distribute copies to the
+#  public, prepare derivative works, and perform publicly and display
+#  publicly, and to permit other to do so.
+#  ___________________________________________________________________________
+
+# from pyomo.contrib.parmest.examples.reactor_design import reactor_design_model
+# if we refactor to use the same create_model function as parmest,
+# we can just import instead of redefining the model
+
+import pyomo.environ as pyo
+from pyomo.dae import ContinuousSet, DerivativeVar
+from pyomo.contrib.doe import (
+    ModelOptionLib,
+    DesignOfExperiments,
+    MeasurementVariables,
+    DesignVariables,
+)
+from pyomo.common.dependencies import numpy as np
+
+
+def create_model_legacy(mod=None, model_option=None):
+    model_option = ModelOptionLib(model_option)
+
+    model = mod
+
+    if model_option == ModelOptionLib.parmest:
+        model = pyo.ConcreteModel()
+        return_m = True
+    elif model_option == ModelOptionLib.stage1 or model_option == ModelOptionLib.stage2:
+        if model is None:
+            raise ValueError(
+                "If model option is stage1 or stage2, a created model needs to be provided."
+            )
+        return_m = False
+    else:
+        raise ValueError(
+            "model_option needs to be defined as parmest, stage1, or stage2."
+        )
+
+    model = _create_model_details(model)
+
+    if return_m:
+        return model
+
+
+def create_model():
+    model = pyo.ConcreteModel()
+    return _create_model_details(model)
+
+
+def _create_model_details(model):
+
+    # Rate constants
+    model.k1 = pyo.Var(initialize=5.0 / 6.0, within=pyo.PositiveReals)  # min^-1
+    model.k2 = pyo.Var(initialize=5.0 / 3.0, within=pyo.PositiveReals)  # min^-1
+    model.k3 = pyo.Var(
+        initialize=1.0 / 6000.0, within=pyo.PositiveReals
+    )  # m^3/(gmol min)
+
+    # Inlet concentration of A, gmol/m^3
+    model.caf = pyo.Var(initialize=10000, within=pyo.PositiveReals)
+
+    # Space velocity (flowrate/volume)
+    model.sv = pyo.Var(initialize=1.0, within=pyo.PositiveReals)
+
+    # Outlet concentration of each component
+    model.ca = pyo.Var(initialize=5000.0, within=pyo.PositiveReals)
+    model.cb = pyo.Var(initialize=2000.0, within=pyo.PositiveReals)
+    model.cc = pyo.Var(initialize=2000.0, within=pyo.PositiveReals)
+    model.cd = pyo.Var(initialize=1000.0, within=pyo.PositiveReals)
+
+    # Constraints
+    model.ca_bal = pyo.Constraint(
+        expr=(
+            0
+            == model.sv * model.caf
+            - model.sv * model.ca
+            - model.k1 * model.ca
+            - 2.0 * model.k3 * model.ca**2.0
+        )
+    )
+
+    model.cb_bal = pyo.Constraint(
+        expr=(0 == -model.sv * model.cb + model.k1 * model.ca - model.k2 * model.cb)
+    )
+
+    model.cc_bal = pyo.Constraint(
+        expr=(0 == -model.sv * model.cc + model.k2 * model.cb)
+    )
+
+    model.cd_bal = pyo.Constraint(
+        expr=(0 == -model.sv * model.cd + model.k3 * model.ca**2.0)
+    )
+
+    return model
+
+
+def main(legacy_create_model_interface=False):
+
+    # measurement object
+    measurements = MeasurementVariables()
+    measurements.add_variables("ca", indices=None, time_index_position=None)
+    measurements.add_variables("cb", indices=None, time_index_position=None)
+    measurements.add_variables("cc", indices=None, time_index_position=None)
+    measurements.add_variables("cd", indices=None, time_index_position=None)
+
+    # design object
+    exp_design = DesignVariables()
+    exp_design.add_variables(
+        "sv",
+        indices=None,
+        time_index_position=None,
+        values=1.0,
+        lower_bounds=0.1,
+        upper_bounds=10.0,
+    )
+    exp_design.add_variables(
+        "caf",
+        indices=None,
+        time_index_position=None,
+        values=10000,
+        lower_bounds=5000,
+        upper_bounds=15000,
+    )
+
+    theta_values = {"k1": 5.0 / 6.0, "k2": 5.0 / 3.0, "k3": 1.0 / 6000.0}
+
+    if legacy_create_model_interface:
+        create_model_ = create_model_legacy
+    else:
+        create_model_ = create_model
+
+    doe1 = DesignOfExperiments(
+        theta_values, exp_design, measurements, create_model_, prior_FIM=None
+    )
+
+    result = doe1.compute_FIM(
+        mode="sequential_finite",  # calculation mode
+        scale_nominal_param_value=True,  # scale nominal parameter value
+        formula="central",  # formula for finite difference
+    )
+
+    # doe1.model.pprint()
+
+    result.result_analysis()
+
+    # print("FIM =\n",result.FIM)
+    # print("jac =\n",result.jaco_information)
+    # print("log10 Trace of FIM: ", np.log10(result.trace))
+    # print("log10 Determinant of FIM: ", np.log10(result.det))
+
+    # test result
+    expected_log10_trace = 6.815
+    log10_trace = np.log10(result.trace)
+    relative_error_trace = abs(log10_trace - 6.815)
+    assert relative_error_trace < 0.01, (
+        "log10(tr(FIM)) regression test failed, answer "
+        + str(round(log10_trace, 3))
+        + " does not match expected answer of "
+        + str(expected_log10_trace)
+    )
+
+    expected_log10_det = 18.719
+    log10_det = np.log10(result.det)
+    relative_error_det = abs(log10_det - 18.719)
+    assert relative_error_det < 0.01, (
+        "log10(det(FIM)) regression test failed, answer "
+        + str(round(log10_det, 3))
+        + " does not match expected answer of "
+        + str(expected_log10_det)
+    )
+
+    doe2 = DesignOfExperiments(
+        theta_values, exp_design, measurements, create_model_, prior_FIM=None
+    )
+
+    square_result2, optimize_result2 = doe2.stochastic_program(
+        if_optimize=True,
+        if_Cholesky=True,
+        scale_nominal_param_value=True,
+        objective_option="det",
+        jac_initial=result.jaco_information.copy(),
+        step=0.1,
+    )
+
+    optimize_result2.result_analysis()
+    log_det = np.log10(optimize_result2.det)
+    print("log(det) = ", round(log_det, 3))
+    log_det_expected = 19.266
+    assert abs(log_det - log_det_expected) < 0.01, "log(det) regression test failed"
+
+    doe3 = DesignOfExperiments(
+        theta_values, exp_design, measurements, create_model_, prior_FIM=None
+    )
+
+    square_result3, optimize_result3 = doe3.stochastic_program(
+        if_optimize=True,
+        scale_nominal_param_value=True,
+        objective_option="trace",
+        jac_initial=result.jaco_information.copy(),
+        step=0.1,
+    )
+
+    optimize_result3.result_analysis()
+    log_trace = np.log10(optimize_result3.trace)
+    log_trace_expected = 7.509
+    print("log(trace) = ", round(log_trace, 3))
+    assert (
+        abs(log_trace - log_trace_expected) < 0.01
+    ), "log(trace) regression test failed"
+
+
+if __name__ == "__main__":
+    main(legacy_create_model_interface=False)
diff --git a/pyomo/contrib/doe/examples/reactor_grid_search.py b/pyomo/contrib/doe/examples/reactor_grid_search.py
index a4516c36451..1f5aae77f85 100644
--- a/pyomo/contrib/doe/examples/reactor_grid_search.py
+++ b/pyomo/contrib/doe/examples/reactor_grid_search.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/doe/examples/reactor_kinetics.py b/pyomo/contrib/doe/examples/reactor_kinetics.py
index 57d06e146c5..ed2175085f2 100644
--- a/pyomo/contrib/doe/examples/reactor_kinetics.py
+++ b/pyomo/contrib/doe/examples/reactor_kinetics.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/doe/examples/reactor_optimize_doe.py b/pyomo/contrib/doe/examples/reactor_optimize_doe.py
index 56ea1ffeac3..f7b4a74c891 100644
--- a/pyomo/contrib/doe/examples/reactor_optimize_doe.py
+++ b/pyomo/contrib/doe/examples/reactor_optimize_doe.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/doe/measurements.py b/pyomo/contrib/doe/measurements.py
index 75fd4f7c485..31a9dc19dbb 100644
--- a/pyomo/contrib/doe/measurements.py
+++ b/pyomo/contrib/doe/measurements.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -26,6 +26,8 @@
 #  ___________________________________________________________________________
 
 import itertools
+import collections.abc
+from pyomo.common.numeric_types import native_numeric_types
 
 
 class VariablesWithIndices:
@@ -93,18 +95,22 @@ def add_variables(
             upper_bounds,
         )
 
-        if values:
+        if values is not None:
+            # if a scalar (int or float) is given, set it as the value for all variables
+            if type(values) in native_numeric_types:
+                values = [values] * len(added_names)
             # this dictionary keys are special set, values are its value
             self.variable_names_value.update(zip(added_names, values))
 
-        # if a scalar (int or float) is given, set it as the lower bound for all variables
-        if lower_bounds:
-            if type(lower_bounds) in [int, float]:
+        if lower_bounds is not None:
+            # if a scalar (int or float) is given, set it as the lower bound for all variables
+            if type(lower_bounds) in native_numeric_types:
                 lower_bounds = [lower_bounds] * len(added_names)
             self.lower_bounds.update(zip(added_names, lower_bounds))
 
-        if upper_bounds:
-            if type(upper_bounds) in [int, float]:
+        if upper_bounds is not None:
+            # if a scalar (int or float) is given, set it as the upper bound for all variables
+            if type(upper_bounds) in native_numeric_types:
                 upper_bounds = [upper_bounds] * len(added_names)
             self.upper_bounds.update(zip(added_names, upper_bounds))
 
@@ -127,7 +133,7 @@ def _generate_variable_names_with_indices(
         """
         # first combine all indices into a list
         all_index_list = []  # contains all index lists
-        if indices:
+        if indices is not None:
             for index_pointer in indices:
                 all_index_list.append(indices[index_pointer])
 
@@ -141,8 +147,14 @@ def _generate_variable_names_with_indices(
         added_names = []
         # iterate over index combinations ["CA", 1], ["CA", 2], ..., ["CC", 2], ["CC", 3]
         for index_instance in all_variable_indices:
-            var_name_index_string = var_name + "["
+            var_name_index_string = var_name
+            #
+            # Suggestion from JS: "Can you re-use name_repr and index_repr from pyomo.core.base.component_namer here?"
+            #
             for i, idx in enumerate(index_instance):
+                # if i is the first index, open the []
+                if i == 0:
+                    var_name_index_string += "["
                 # use repr() is different from using str()
                 # with repr(), "CA" is "CA", with str(), "CA" is CA. The first is not valid in our interface.
                 var_name_index_string += str(idx)
@@ -171,28 +183,45 @@ def _check_valid_input(
         """
         Check if the measurement information provided are valid to use.
         """
-        assert type(var_name) is str, "var_name should be a string."
+        if not isinstance(var_name, str):
+            raise TypeError("Variable name must be a string.")
 
-        if time_index_position not in indices:
+        # debugging note: what is an integer versus a list versus a dictionary here?
+        # check if time_index_position is in indices
+        if (
+            indices is not None  # ensure not None
+            and time_index_position is not None  # ensure not None
+            and time_index_position
+            not in indices.keys()  # ensure time_index_position is in indices
+        ):
             raise ValueError("time index cannot be found in indices.")
 
-        # if given a list, check if bounds have the same length with flattened variable
-        if values and len(values) != len_indices:
+        # if given a list, check if values have the same length with flattened variable
+        if (
+            values is not None  # ensure not None
+            and not type(values)
+            in native_numeric_types  # skip this test if scalar (int or float)
+            and len(values) != len_indices
+        ):
             raise ValueError("Values is of different length with indices.")
 
         if (
-            lower_bounds
-            and type(lower_bounds) == list
-            and len(lower_bounds) != len_indices
+            lower_bounds is not None  # ensure not None
+            and not type(lower_bounds)
+            in native_numeric_types  # skip this test if scalar (int or float)
+            and isinstance(lower_bounds, collections.abc.Sequence)  # ensure list-like
+            and len(lower_bounds) != len_indices  # ensure same length
         ):
-            raise ValueError("Lowerbounds is of different length with indices.")
+            raise ValueError("Lowerbounds have a different length with indices.")
 
         if (
-            upper_bounds
-            and type(upper_bounds) == list
-            and len(upper_bounds) != len_indices
+            upper_bounds is not None  # ensure not None
+            and not type(upper_bounds)
+            in native_numeric_types  # skip this test if scalar (int or float)
+            and isinstance(upper_bounds, collections.abc.Sequence)  # ensure list-like
+            and len(upper_bounds) != len_indices  # ensure same length
         ):
-            raise ValueError("Upperbounds is of different length with indices.")
+            raise ValueError("Upperbounds have a different length with indices.")
 
 
 class MeasurementVariables(VariablesWithIndices):
diff --git a/pyomo/contrib/doe/result.py b/pyomo/contrib/doe/result.py
index 65ded38a63b..f7145ae2a46 100644
--- a/pyomo/contrib/doe/result.py
+++ b/pyomo/contrib/doe/result.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -123,9 +123,9 @@ def result_analysis(self, result=None):
         if self.prior_FIM is not None:
             try:
                 fim = fim + self.prior_FIM
-                self.logger.info('Existed information has been added.')
+                self.logger.info("Existed information has been added.")
             except:
-                raise ValueError('Check the shape of prior FIM.')
+                raise ValueError("Check the shape of prior FIM.")
 
         if np.linalg.cond(fim) > self.max_condition_number:
             self.logger.info(
@@ -133,7 +133,7 @@ def result_analysis(self, result=None):
                 np.linalg.cond(fim),
             )
             self.logger.info(
-                'A condition number bigger than %s is considered near singular.',
+                "A condition number bigger than %s is considered near singular.",
                 self.max_condition_number,
             )
 
@@ -239,10 +239,10 @@ def _print_FIM_info(self, FIM):
         self.eig_vecs = np.linalg.eig(FIM)[1]
 
         self.logger.info(
-            'FIM: %s; \n Trace: %s; \n Determinant: %s;', self.FIM, self.trace, self.det
+            "FIM: %s; \n Trace: %s; \n Determinant: %s;", self.FIM, self.trace, self.det
         )
         self.logger.info(
-            'Condition number: %s; \n Min eigenvalue: %s.', self.cond, self.min_eig
+            "Condition number: %s; \n Min eigenvalue: %s.", self.cond, self.min_eig
         )
 
     def _solution_info(self, m, dv_set):
@@ -268,11 +268,11 @@ def _solution_info(self, m, dv_set):
         # When scaled with constant values, the effect of the scaling factors are removed here
         # For determinant, the scaling factor to determinant is scaling factor ** (Dim of FIM)
         # For trace, the scaling factor to trace is the scaling factor.
-        if self.obj == 'det':
+        if self.obj == "det":
             self.obj_det = np.exp(value(m.obj)) / (self.fim_scale_constant_value) ** (
                 len(self.parameter_names)
             )
-        elif self.obj == 'trace':
+        elif self.obj == "trace":
             self.obj_trace = np.exp(value(m.obj)) / (self.fim_scale_constant_value)
 
         design_variable_names = list(dv_set.keys())
@@ -314,11 +314,11 @@ def _get_solver_info(self):
         if (self.result.solver.status == SolverStatus.ok) and (
             self.result.solver.termination_condition == TerminationCondition.optimal
         ):
-            self.status = 'converged'
+            self.status = "converged"
         elif (
             self.result.solver.termination_condition == TerminationCondition.infeasible
         ):
-            self.status = 'infeasible'
+            self.status = "infeasible"
         else:
             self.status = self.result.solver.status
 
@@ -399,10 +399,10 @@ def extract_criteria(self):
                 column_names.append(i)
 
         # Each design criteria has a column to store values
-        column_names.append('A')
-        column_names.append('D')
-        column_names.append('E')
-        column_names.append('ME')
+        column_names.append("A")
+        column_names.append("D")
+        column_names.append("E")
+        column_names.append("ME")
         # generate the dataframe
         store_all_results = np.asarray(store_all_results)
         self.store_all_results_dataframe = pd.DataFrame(
@@ -458,7 +458,7 @@ def figure_drawing(
             self.design_names
         ):
             raise ValueError(
-                'Error: All dimensions except for those the figures are drawn by should be fixed.'
+                "Error: All dimensions except for those the figures are drawn by should be fixed."
             )
 
         if len(self.sensitivity_dimension) not in [1, 2]:
@@ -467,15 +467,15 @@ def figure_drawing(
         # generate a combination of logic sentences to filter the results of the DOF needed.
         # an example filter: (self.store_all_results_dataframe["CA0"]==5).
         if len(self.fixed_design_names) != 0:
-            filter = ''
+            filter = ""
             for i in range(len(self.fixed_design_names)):
-                filter += '(self.store_all_results_dataframe['
+                filter += "(self.store_all_results_dataframe["
                 filter += str(self.fixed_design_names[i])
-                filter += ']=='
+                filter += "]=="
                 filter += str(self.fixed_design_values[i])
-                filter += ')'
+                filter += ")"
                 if i != (len(self.fixed_design_names) - 1):
-                    filter += '&'
+                    filter += "&"
             # extract results with other dimensions fixed
             figure_result_data = self.store_all_results_dataframe.loc[eval(filter)]
         # if there is no other fixed dimensions
@@ -526,78 +526,78 @@ def _curve1D(
 
         # decide if the results are log scaled
         if log_scale:
-            y_range_A = np.log10(self.figure_result_data['A'].values.tolist())
-            y_range_D = np.log10(self.figure_result_data['D'].values.tolist())
-            y_range_E = np.log10(self.figure_result_data['E'].values.tolist())
-            y_range_ME = np.log10(self.figure_result_data['ME'].values.tolist())
+            y_range_A = np.log10(self.figure_result_data["A"].values.tolist())
+            y_range_D = np.log10(self.figure_result_data["D"].values.tolist())
+            y_range_E = np.log10(self.figure_result_data["E"].values.tolist())
+            y_range_ME = np.log10(self.figure_result_data["ME"].values.tolist())
         else:
-            y_range_A = self.figure_result_data['A'].values.tolist()
-            y_range_D = self.figure_result_data['D'].values.tolist()
-            y_range_E = self.figure_result_data['E'].values.tolist()
-            y_range_ME = self.figure_result_data['ME'].values.tolist()
+            y_range_A = self.figure_result_data["A"].values.tolist()
+            y_range_D = self.figure_result_data["D"].values.tolist()
+            y_range_E = self.figure_result_data["E"].values.tolist()
+            y_range_ME = self.figure_result_data["ME"].values.tolist()
 
         # Draw A-optimality
         fig = plt.pyplot.figure()
-        plt.pyplot.rc('axes', titlesize=font_axes)
-        plt.pyplot.rc('axes', labelsize=font_axes)
-        plt.pyplot.rc('xtick', labelsize=font_tick)
-        plt.pyplot.rc('ytick', labelsize=font_tick)
+        plt.pyplot.rc("axes", titlesize=font_axes)
+        plt.pyplot.rc("axes", labelsize=font_axes)
+        plt.pyplot.rc("xtick", labelsize=font_tick)
+        plt.pyplot.rc("ytick", labelsize=font_tick)
         ax = fig.add_subplot(111)
-        params = {'mathtext.default': 'regular'}
+        params = {"mathtext.default": "regular"}
         # plt.rcParams.update(params)
         ax.plot(x_range, y_range_A)
         ax.scatter(x_range, y_range_A)
-        ax.set_ylabel('$log_{10}$ Trace')
+        ax.set_ylabel("$log_{10}$ Trace")
         ax.set_xlabel(xlabel_text)
-        plt.pyplot.title(title_text + ' - A optimality')
+        plt.pyplot.title(title_text + ": A-optimality")
         plt.pyplot.show()
 
         # Draw D-optimality
         fig = plt.pyplot.figure()
-        plt.pyplot.rc('axes', titlesize=font_axes)
-        plt.pyplot.rc('axes', labelsize=font_axes)
-        plt.pyplot.rc('xtick', labelsize=font_tick)
-        plt.pyplot.rc('ytick', labelsize=font_tick)
+        plt.pyplot.rc("axes", titlesize=font_axes)
+        plt.pyplot.rc("axes", labelsize=font_axes)
+        plt.pyplot.rc("xtick", labelsize=font_tick)
+        plt.pyplot.rc("ytick", labelsize=font_tick)
         ax = fig.add_subplot(111)
-        params = {'mathtext.default': 'regular'}
+        params = {"mathtext.default": "regular"}
         # plt.rcParams.update(params)
         ax.plot(x_range, y_range_D)
         ax.scatter(x_range, y_range_D)
-        ax.set_ylabel('$log_{10}$ Determinant')
+        ax.set_ylabel("$log_{10}$ Determinant")
         ax.set_xlabel(xlabel_text)
-        plt.pyplot.title(title_text + ' - D optimality')
+        plt.pyplot.title(title_text + ": D-optimality")
         plt.pyplot.show()
 
         # Draw E-optimality
         fig = plt.pyplot.figure()
-        plt.pyplot.rc('axes', titlesize=font_axes)
-        plt.pyplot.rc('axes', labelsize=font_axes)
-        plt.pyplot.rc('xtick', labelsize=font_tick)
-        plt.pyplot.rc('ytick', labelsize=font_tick)
+        plt.pyplot.rc("axes", titlesize=font_axes)
+        plt.pyplot.rc("axes", labelsize=font_axes)
+        plt.pyplot.rc("xtick", labelsize=font_tick)
+        plt.pyplot.rc("ytick", labelsize=font_tick)
         ax = fig.add_subplot(111)
-        params = {'mathtext.default': 'regular'}
+        params = {"mathtext.default": "regular"}
         # plt.rcParams.update(params)
         ax.plot(x_range, y_range_E)
         ax.scatter(x_range, y_range_E)
-        ax.set_ylabel('$log_{10}$ Minimal eigenvalue')
+        ax.set_ylabel("$log_{10}$ Minimal eigenvalue")
         ax.set_xlabel(xlabel_text)
-        plt.pyplot.title(title_text + ' - E optimality')
+        plt.pyplot.title(title_text + ": E-optimality")
         plt.pyplot.show()
 
         # Draw Modified E-optimality
         fig = plt.pyplot.figure()
-        plt.pyplot.rc('axes', titlesize=font_axes)
-        plt.pyplot.rc('axes', labelsize=font_axes)
-        plt.pyplot.rc('xtick', labelsize=font_tick)
-        plt.pyplot.rc('ytick', labelsize=font_tick)
+        plt.pyplot.rc("axes", titlesize=font_axes)
+        plt.pyplot.rc("axes", labelsize=font_axes)
+        plt.pyplot.rc("xtick", labelsize=font_tick)
+        plt.pyplot.rc("ytick", labelsize=font_tick)
         ax = fig.add_subplot(111)
-        params = {'mathtext.default': 'regular'}
+        params = {"mathtext.default": "regular"}
         # plt.rcParams.update(params)
         ax.plot(x_range, y_range_ME)
         ax.scatter(x_range, y_range_ME)
-        ax.set_ylabel('$log_{10}$ Condition number')
+        ax.set_ylabel("$log_{10}$ Condition number")
         ax.set_xlabel(xlabel_text)
-        plt.pyplot.title(title_text + ' - Modified E optimality')
+        plt.pyplot.title(title_text + ": Modified E-optimality")
         plt.pyplot.show()
 
     def _heatmap(
@@ -641,10 +641,10 @@ def _heatmap(
         y_range = sensitivity_dict[self.sensitivity_dimension[1]]
 
         # extract the design criteria values
-        A_range = self.figure_result_data['A'].values.tolist()
-        D_range = self.figure_result_data['D'].values.tolist()
-        E_range = self.figure_result_data['E'].values.tolist()
-        ME_range = self.figure_result_data['ME'].values.tolist()
+        A_range = self.figure_result_data["A"].values.tolist()
+        D_range = self.figure_result_data["D"].values.tolist()
+        E_range = self.figure_result_data["E"].values.tolist()
+        ME_range = self.figure_result_data["ME"].values.tolist()
 
         # reshape the design criteria values for heatmaps
         cri_a = np.asarray(A_range).reshape(len(x_range), len(y_range))
@@ -675,12 +675,12 @@ def _heatmap(
 
         # A-optimality
         fig = plt.pyplot.figure()
-        plt.pyplot.rc('axes', titlesize=font_axes)
-        plt.pyplot.rc('axes', labelsize=font_axes)
-        plt.pyplot.rc('xtick', labelsize=font_tick)
-        plt.pyplot.rc('ytick', labelsize=font_tick)
+        plt.pyplot.rc("axes", titlesize=font_axes)
+        plt.pyplot.rc("axes", labelsize=font_axes)
+        plt.pyplot.rc("xtick", labelsize=font_tick)
+        plt.pyplot.rc("ytick", labelsize=font_tick)
         ax = fig.add_subplot(111)
-        params = {'mathtext.default': 'regular'}
+        params = {"mathtext.default": "regular"}
         plt.pyplot.rcParams.update(params)
         ax.set_yticks(range(len(yLabel)))
         ax.set_yticklabels(yLabel)
@@ -690,18 +690,18 @@ def _heatmap(
         ax.set_xlabel(xlabel_text)
         im = ax.imshow(hes_a.T, cmap=plt.pyplot.cm.hot_r)
         ba = plt.pyplot.colorbar(im)
-        ba.set_label('log10(trace(FIM))')
-        plt.pyplot.title(title_text + ' - A optimality')
+        ba.set_label("log10(trace(FIM))")
+        plt.pyplot.title(title_text + ": A-optimality")
         plt.pyplot.show()
 
         # D-optimality
         fig = plt.pyplot.figure()
-        plt.pyplot.rc('axes', titlesize=font_axes)
-        plt.pyplot.rc('axes', labelsize=font_axes)
-        plt.pyplot.rc('xtick', labelsize=font_tick)
-        plt.pyplot.rc('ytick', labelsize=font_tick)
+        plt.pyplot.rc("axes", titlesize=font_axes)
+        plt.pyplot.rc("axes", labelsize=font_axes)
+        plt.pyplot.rc("xtick", labelsize=font_tick)
+        plt.pyplot.rc("ytick", labelsize=font_tick)
         ax = fig.add_subplot(111)
-        params = {'mathtext.default': 'regular'}
+        params = {"mathtext.default": "regular"}
         plt.pyplot.rcParams.update(params)
         ax.set_yticks(range(len(yLabel)))
         ax.set_yticklabels(yLabel)
@@ -711,18 +711,18 @@ def _heatmap(
         ax.set_xlabel(xlabel_text)
         im = ax.imshow(hes_d.T, cmap=plt.pyplot.cm.hot_r)
         ba = plt.pyplot.colorbar(im)
-        ba.set_label('log10(det(FIM))')
-        plt.pyplot.title(title_text + ' - D optimality')
+        ba.set_label("log10(det(FIM))")
+        plt.pyplot.title(title_text + ": D-optimality")
         plt.pyplot.show()
 
         # E-optimality
         fig = plt.pyplot.figure()
-        plt.pyplot.rc('axes', titlesize=font_axes)
-        plt.pyplot.rc('axes', labelsize=font_axes)
-        plt.pyplot.rc('xtick', labelsize=font_tick)
-        plt.pyplot.rc('ytick', labelsize=font_tick)
+        plt.pyplot.rc("axes", titlesize=font_axes)
+        plt.pyplot.rc("axes", labelsize=font_axes)
+        plt.pyplot.rc("xtick", labelsize=font_tick)
+        plt.pyplot.rc("ytick", labelsize=font_tick)
         ax = fig.add_subplot(111)
-        params = {'mathtext.default': 'regular'}
+        params = {"mathtext.default": "regular"}
         plt.pyplot.rcParams.update(params)
         ax.set_yticks(range(len(yLabel)))
         ax.set_yticklabels(yLabel)
@@ -732,18 +732,18 @@ def _heatmap(
         ax.set_xlabel(xlabel_text)
         im = ax.imshow(hes_e.T, cmap=plt.pyplot.cm.hot_r)
         ba = plt.pyplot.colorbar(im)
-        ba.set_label('log10(minimal eig(FIM))')
-        plt.pyplot.title(title_text + ' - E optimality')
+        ba.set_label("log10(minimal eig(FIM))")
+        plt.pyplot.title(title_text + ": E-optimality")
         plt.pyplot.show()
 
         # modified E-optimality
         fig = plt.pyplot.figure()
-        plt.pyplot.rc('axes', titlesize=font_axes)
-        plt.pyplot.rc('axes', labelsize=font_axes)
-        plt.pyplot.rc('xtick', labelsize=font_tick)
-        plt.pyplot.rc('ytick', labelsize=font_tick)
+        plt.pyplot.rc("axes", titlesize=font_axes)
+        plt.pyplot.rc("axes", labelsize=font_axes)
+        plt.pyplot.rc("xtick", labelsize=font_tick)
+        plt.pyplot.rc("ytick", labelsize=font_tick)
         ax = fig.add_subplot(111)
-        params = {'mathtext.default': 'regular'}
+        params = {"mathtext.default": "regular"}
         plt.pyplot.rcParams.update(params)
         ax.set_yticks(range(len(yLabel)))
         ax.set_yticklabels(yLabel)
@@ -753,6 +753,6 @@ def _heatmap(
         ax.set_xlabel(xlabel_text)
         im = ax.imshow(hes_e2.T, cmap=plt.pyplot.cm.hot_r)
         ba = plt.pyplot.colorbar(im)
-        ba.set_label('log10(cond(FIM))')
-        plt.pyplot.title(title_text + ' - Modified E-optimality')
+        ba.set_label("log10(cond(FIM))")
+        plt.pyplot.title(title_text + ": Modified E-optimality")
         plt.pyplot.show()
diff --git a/pyomo/contrib/doe/scenario.py b/pyomo/contrib/doe/scenario.py
index eff9c883e0b..b44ce1ab4d3 100644
--- a/pyomo/contrib/doe/scenario.py
+++ b/pyomo/contrib/doe/scenario.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -150,5 +150,5 @@ def generate_scenario(self):
 
         # store scenario
         if self.store:
-            with open('scenario_simultaneous.pickle', 'wb') as f:
+            with open("scenario_simultaneous.pickle", "wb") as f:
                 pickle.dump(self.scenario_data, f)
diff --git a/pyomo/contrib/doe/tests/__init__.py b/pyomo/contrib/doe/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/doe/tests/__init__.py
+++ b/pyomo/contrib/doe/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/doe/tests/test_example.py b/pyomo/contrib/doe/tests/test_example.py
index 0f143e03677..e4ffbe89142 100644
--- a/pyomo/contrib/doe/tests/test_example.py
+++ b/pyomo/contrib/doe/tests/test_example.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -38,10 +38,10 @@
 
 from pyomo.opt import SolverFactory
 
-ipopt_available = SolverFactory('ipopt').available()
+ipopt_available = SolverFactory("ipopt").available()
 
 
-class TestReactorExample(unittest.TestCase):
+class TestReactorExamples(unittest.TestCase):
     @unittest.skipIf(not ipopt_available, "The 'ipopt' command is not available")
     @unittest.skipIf(not scipy_available, "scipy is not available")
     @unittest.skipIf(not numpy_available, "Numpy is not available")
@@ -65,6 +65,22 @@ def test_reactor_grid_search(self):
 
         reactor_grid_search.main()
 
+    @unittest.skipIf(not ipopt_available, "The 'ipopt' command is not available")
+    @unittest.skipIf(not pandas_available, "pandas is not available")
+    @unittest.skipIf(not numpy_available, "Numpy is not available")
+    def test_reactor_design_slim_create_model_interface(self):
+        from pyomo.contrib.doe.examples import reactor_design
+
+        reactor_design.main(legacy_create_model_interface=False)
+
+    @unittest.skipIf(not ipopt_available, "The 'ipopt' command is not available")
+    @unittest.skipIf(not pandas_available, "pandas is not available")
+    @unittest.skipIf(not numpy_available, "Numpy is not available")
+    def test_reactor_design_legacy_create_model_interface(self):
+        from pyomo.contrib.doe.examples import reactor_design
+
+        reactor_design.main(legacy_create_model_interface=True)
+
 
 if __name__ == "__main__":
     unittest.main()
diff --git a/pyomo/contrib/doe/tests/test_fim_doe.py b/pyomo/contrib/doe/tests/test_fim_doe.py
index 42b463162b2..d9a8d60fdb4 100644
--- a/pyomo/contrib/doe/tests/test_fim_doe.py
+++ b/pyomo/contrib/doe/tests/test_fim_doe.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -38,16 +38,124 @@
 
 
 class TestMeasurementError(unittest.TestCase):
-    def test(self):
-        t_control = [0, 0.125, 0.25, 0.375, 0.5, 0.625, 0.75, 0.875, 1]
-        variable_name = "C"
-        indices = {0: ['CA', 'CB', 'CC'], 1: t_control}
-        # measurement object
-        measurements = MeasurementVariables()
+
+    def test_with_time_plus_one_extra_index(self):
+        """This tests confirms the typical usage with a time index plus one extra index.
+
+        This test should execute without throwing any errors.
+
+        """
+
+        MeasurementVariables().add_variables(
+            "C", indices={0: ["A", "B", "C"], 1: [0, 0.5, 1.0]}, time_index_position=1
+        )
+
+    def test_with_time_plus_two_extra_indices(self):
+        """This tests confirms the typical usage with a time index plus two extra indices.
+
+        This test should execute without throwing any errors.
+
+        """
+
+        MeasurementVariables().add_variables(
+            "C",
+            indices={
+                0: ["A", "B", "C"],  # species
+                1: [0, 0.5, 1.0],  # time
+                2: [1, 2, 3],
+            },  # position
+            time_index_position=1,
+        )
+
+    def test_time_index_position_out_of_bounds(self):
+        """This test confirms that an error is thrown when the time index position is out of bounds."""
+
         # if time index is not in indices, an value error is thrown.
         with self.assertRaises(ValueError):
-            measurements.add_variables(
-                variable_name, indices=indices, time_index_position=2
+            MeasurementVariables().add_variables(
+                "C",
+                indices={0: ["CA", "CB", "CC"], 1: [0, 0.5, 1.0]},  # species  # time
+                time_index_position=2,  # this is out of bounds
+            )
+
+    def test_single_measurement_variable(self):
+        """This test confirms we can specify a single measurement variable without
+        specifying the indices.
+
+        The test should execute with no errors.
+        """
+        measurements = MeasurementVariables()
+        measurements.add_variables("HelloWorld", indices=None, time_index_position=None)
+
+    def test_without_time_index(self):
+        """This test confirms we can add a measurement variable without specifying the time index.
+
+        The test should execute with no errors.
+
+        """
+
+        MeasurementVariables().add_variables(
+            "C",
+            indices={0: ["CA", "CB", "CC"]},  # species as only index
+            time_index_position=None,  # no time index
+        )
+
+    def test_only_time_index(self):
+        """This test confirms we can add a measurement variable without specifying the variable name.
+
+        The test should execute with no errors.
+
+        """
+
+        MeasurementVariables().add_variables(
+            "HelloWorld",  # name of the variable
+            indices={0: [0, 0.5, 1.0]},
+            time_index_position=0,
+        )
+
+    def test_with_no_measurement_name(self):
+        """This test confirms that an error is thrown when None is used as the measurement name."""
+
+        with self.assertRaises(TypeError):
+            MeasurementVariables().add_variables(
+                None, indices={0: [0, 0.5, 1.0]}, time_index_position=0
+            )
+
+    def test_with_non_string_measurement_name(self):
+        """This test confirms that an error is thrown when a non-string is used as the measurement name."""
+
+        with self.assertRaises(TypeError):
+            MeasurementVariables().add_variables(
+                1, indices={0: [0, 0.5, 1.0]}, time_index_position=0
+            )
+
+    def test_non_integer_index_keys(self):
+        """This test confirms that strings can be used as keys for specifying the indices.
+
+        Warning: it is possible this usage breaks something else in Pyomo.DoE.
+        There may be an implicit assumption that the order of the keys must match the order
+        of the indices in the Pyomo model.
+
+        """
+
+        MeasurementVariables().add_variables(
+            "C",
+            indices={"species": ["CA", "CB", "CC"], "time": [0, 0.5, 1.0]},
+            time_index_position="time",
+        )
+
+    def test_no_measurements(self):
+        """This test confirms that an error is thrown when the user forgets to add any measurements.
+
+        It's okay to have no decision variables. With no measurement variables, the FIM is the zero matrix.
+        This (no measurements) is a common user mistake.
+        """
+
+        with self.assertRaises(ValueError):
+            decisions = DesignVariables()
+            measurements = MeasurementVariables()
+            DesignOfExperiments(
+                {}, decisions, measurements, create_model, disc_for_measure
             )
 
 
@@ -58,7 +166,7 @@ def test(self):
         exp_design = DesignVariables()
 
         # add T as design variable
-        var_T = 'T'
+        var_T = "T"
         indices_T = {0: t_control}
         exp1_T = [470, 300, 300, 300, 300, 300, 300, 300, 300]
 
@@ -94,7 +202,7 @@ def test(self):
         t_control = [0, 0.125, 0.25, 0.375, 0.5, 0.625, 0.75, 0.875, 1]
         # measurement object
         variable_name = "C"
-        indices = {0: ['CA', 'CB', 'CC'], 1: t_control}
+        indices = {0: ["CA", "CB", "CC"], 1: t_control}
 
         measurements = MeasurementVariables()
         measurements.add_variables(
@@ -105,7 +213,7 @@ def test(self):
         exp_design = DesignVariables()
 
         # add CAO as design variable
-        var_C = 'CA0'
+        var_C = "CA0"
         indices_C = {0: [0]}
         exp1_C = [5]
         exp_design.add_variables(
@@ -118,7 +226,7 @@ def test(self):
         )
 
         # add T as design variable
-        var_T = 'T'
+        var_T = "T"
         indices_T = {0: t_control}
         exp1_T = [470, 300, 300, 300, 300, 300, 300, 300, 300]
 
@@ -165,7 +273,7 @@ def test_setup(self):
 
         # add variable C
         variable_name = "C"
-        indices = {0: ['CA', 'CB', 'CC'], 1: t_control}
+        indices = {0: ["CA", "CB", "CC"], 1: t_control}
         measurements.add_variables(
             variable_name, indices=indices, time_index_position=1
         )
@@ -178,36 +286,36 @@ def test_setup(self):
         )
 
         # check variable names
-        self.assertEqual(measurements.variable_names[0], 'C[CA,0]')
-        self.assertEqual(measurements.variable_names[1], 'C[CA,0.125]')
-        self.assertEqual(measurements.variable_names[-1], 'T[5,0.8]')
-        self.assertEqual(measurements.variable_names[-2], 'T[5,0.6]')
-        self.assertEqual(measurements.variance['T[5,0.4]'], 10)
-        self.assertEqual(measurements.variance['T[5,0.6]'], 10)
-        self.assertEqual(measurements.variance['T[5,0.4]'], 10)
-        self.assertEqual(measurements.variance['T[5,0.6]'], 10)
+        self.assertEqual(measurements.variable_names[0], "C[CA,0]")
+        self.assertEqual(measurements.variable_names[1], "C[CA,0.125]")
+        self.assertEqual(measurements.variable_names[-1], "T[5,0.8]")
+        self.assertEqual(measurements.variable_names[-2], "T[5,0.6]")
+        self.assertEqual(measurements.variance["T[5,0.4]"], 10)
+        self.assertEqual(measurements.variance["T[5,0.6]"], 10)
+        self.assertEqual(measurements.variance["T[5,0.4]"], 10)
+        self.assertEqual(measurements.variance["T[5,0.6]"], 10)
 
         ### specify function
         var_names = [
-            'C[CA,0]',
-            'C[CA,0.125]',
-            'C[CA,0.875]',
-            'C[CA,1]',
-            'C[CB,0]',
-            'C[CB,0.125]',
-            'C[CB,0.25]',
-            'C[CB,0.375]',
-            'C[CC,0]',
-            'C[CC,0.125]',
-            'C[CC,0.25]',
-            'C[CC,0.375]',
+            "C[CA,0]",
+            "C[CA,0.125]",
+            "C[CA,0.875]",
+            "C[CA,1]",
+            "C[CB,0]",
+            "C[CB,0.125]",
+            "C[CB,0.25]",
+            "C[CB,0.375]",
+            "C[CC,0]",
+            "C[CC,0.125]",
+            "C[CC,0.25]",
+            "C[CC,0.375]",
         ]
 
         measurements2 = MeasurementVariables()
         measurements2.set_variable_name_list(var_names)
 
-        self.assertEqual(measurements2.variable_names[1], 'C[CA,0.125]')
-        self.assertEqual(measurements2.variable_names[-1], 'C[CC,0.375]')
+        self.assertEqual(measurements2.variable_names[1], "C[CA,0.125]")
+        self.assertEqual(measurements2.variable_names[-1], "C[CC,0.375]")
 
         ### check_subset function
         self.assertTrue(measurements.check_subset(measurements2))
@@ -223,7 +331,7 @@ def test_setup(self):
         exp_design = DesignVariables()
 
         # add CAO as design variable
-        var_C = 'CA0'
+        var_C = "CA0"
         indices_C = {0: [0]}
         exp1_C = [5]
         exp_design.add_variables(
@@ -236,7 +344,7 @@ def test_setup(self):
         )
 
         # add T as design variable
-        var_T = 'T'
+        var_T = "T"
         indices_T = {0: t_control}
         exp1_T = [470, 300, 300, 300, 300, 300, 300, 300, 300]
 
@@ -252,31 +360,31 @@ def test_setup(self):
         self.assertEqual(
             exp_design.variable_names,
             [
-                'CA0[0]',
-                'T[0]',
-                'T[0.125]',
-                'T[0.25]',
-                'T[0.375]',
-                'T[0.5]',
-                'T[0.625]',
-                'T[0.75]',
-                'T[0.875]',
-                'T[1]',
+                "CA0[0]",
+                "T[0]",
+                "T[0.125]",
+                "T[0.25]",
+                "T[0.375]",
+                "T[0.5]",
+                "T[0.625]",
+                "T[0.75]",
+                "T[0.875]",
+                "T[1]",
             ],
         )
-        self.assertEqual(exp_design.variable_names_value['CA0[0]'], 5)
-        self.assertEqual(exp_design.variable_names_value['T[0]'], 470)
-        self.assertEqual(exp_design.upper_bounds['CA0[0]'], 5)
-        self.assertEqual(exp_design.upper_bounds['T[0]'], 700)
-        self.assertEqual(exp_design.lower_bounds['CA0[0]'], 1)
-        self.assertEqual(exp_design.lower_bounds['T[0]'], 300)
+        self.assertEqual(exp_design.variable_names_value["CA0[0]"], 5)
+        self.assertEqual(exp_design.variable_names_value["T[0]"], 470)
+        self.assertEqual(exp_design.upper_bounds["CA0[0]"], 5)
+        self.assertEqual(exp_design.upper_bounds["T[0]"], 700)
+        self.assertEqual(exp_design.lower_bounds["CA0[0]"], 1)
+        self.assertEqual(exp_design.lower_bounds["T[0]"], 300)
 
         design_names = exp_design.variable_names
         exp1 = [4, 600, 300, 300, 300, 300, 300, 300, 300, 300]
         exp1_design_dict = dict(zip(design_names, exp1))
         exp_design.update_values(exp1_design_dict)
-        self.assertEqual(exp_design.variable_names_value['CA0[0]'], 4)
-        self.assertEqual(exp_design.variable_names_value['T[0]'], 600)
+        self.assertEqual(exp_design.variable_names_value["CA0[0]"], 4)
+        self.assertEqual(exp_design.variable_names_value["T[0]"], 600)
 
 
 class TestParameter(unittest.TestCase):
@@ -284,19 +392,19 @@ class TestParameter(unittest.TestCase):
 
     def test_setup(self):
         # set up parameter class
-        param_dict = {'A1': 84.79, 'A2': 371.72, 'E1': 7.78, 'E2': 15.05}
+        param_dict = {"A1": 84.79, "A2": 371.72, "E1": 7.78, "E2": 15.05}
 
         scenario_gene = ScenarioGenerator(param_dict, formula="central", step=0.1)
         parameter_set = scenario_gene.ScenarioData
 
-        self.assertAlmostEqual(parameter_set.eps_abs['A1'], 16.9582, places=1)
-        self.assertAlmostEqual(parameter_set.eps_abs['E1'], 1.5554, places=1)
-        self.assertEqual(parameter_set.scena_num['A2'], [2, 3])
-        self.assertEqual(parameter_set.scena_num['E1'], [4, 5])
-        self.assertAlmostEqual(parameter_set.scenario[0]['A1'], 93.2699, places=1)
-        self.assertAlmostEqual(parameter_set.scenario[2]['A2'], 408.8895, places=1)
-        self.assertAlmostEqual(parameter_set.scenario[-1]['E2'], 13.54, places=1)
-        self.assertAlmostEqual(parameter_set.scenario[-2]['E2'], 16.55, places=1)
+        self.assertAlmostEqual(parameter_set.eps_abs["A1"], 16.9582, places=1)
+        self.assertAlmostEqual(parameter_set.eps_abs["E1"], 1.5554, places=1)
+        self.assertEqual(parameter_set.scena_num["A2"], [2, 3])
+        self.assertEqual(parameter_set.scena_num["E1"], [4, 5])
+        self.assertAlmostEqual(parameter_set.scenario[0]["A1"], 93.2699, places=1)
+        self.assertAlmostEqual(parameter_set.scenario[2]["A2"], 408.8895, places=1)
+        self.assertAlmostEqual(parameter_set.scenario[-1]["E2"], 13.54, places=1)
+        self.assertAlmostEqual(parameter_set.scenario[-2]["E2"], 16.55, places=1)
 
 
 class TestVariablesWithIndices(unittest.TestCase):
@@ -307,7 +415,7 @@ def test_setup(self):
         t_control = [0, 0.125, 0.25, 0.375, 0.5, 0.625, 0.75, 0.875, 1]
         ### add_element function
         # add CAO as design variable
-        var_C = 'CA0'
+        var_C = "CA0"
         indices_C = {0: [0]}
         exp1_C = [5]
         special.add_variables(
@@ -320,7 +428,7 @@ def test_setup(self):
         )
 
         # add T as design variable
-        var_T = 'T'
+        var_T = "T"
         indices_T = {0: t_control}
         exp1_T = [470, 300, 300, 300, 300, 300, 300, 300, 300]
 
@@ -336,25 +444,25 @@ def test_setup(self):
         self.assertEqual(
             special.variable_names,
             [
-                'CA0[0]',
-                'T[0]',
-                'T[0.125]',
-                'T[0.25]',
-                'T[0.375]',
-                'T[0.5]',
-                'T[0.625]',
-                'T[0.75]',
-                'T[0.875]',
-                'T[1]',
+                "CA0[0]",
+                "T[0]",
+                "T[0.125]",
+                "T[0.25]",
+                "T[0.375]",
+                "T[0.5]",
+                "T[0.625]",
+                "T[0.75]",
+                "T[0.875]",
+                "T[1]",
             ],
         )
-        self.assertEqual(special.variable_names_value['CA0[0]'], 5)
-        self.assertEqual(special.variable_names_value['T[0]'], 470)
-        self.assertEqual(special.upper_bounds['CA0[0]'], 5)
-        self.assertEqual(special.upper_bounds['T[0]'], 700)
-        self.assertEqual(special.lower_bounds['CA0[0]'], 1)
-        self.assertEqual(special.lower_bounds['T[0]'], 300)
+        self.assertEqual(special.variable_names_value["CA0[0]"], 5)
+        self.assertEqual(special.variable_names_value["T[0]"], 470)
+        self.assertEqual(special.upper_bounds["CA0[0]"], 5)
+        self.assertEqual(special.upper_bounds["T[0]"], 700)
+        self.assertEqual(special.lower_bounds["CA0[0]"], 1)
+        self.assertEqual(special.lower_bounds["T[0]"], 300)
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     unittest.main()
diff --git a/pyomo/contrib/doe/tests/test_reactor_example.py b/pyomo/contrib/doe/tests/test_reactor_example.py
index 86c914ec4e0..19fb4e61820 100644
--- a/pyomo/contrib/doe/tests/test_reactor_example.py
+++ b/pyomo/contrib/doe/tests/test_reactor_example.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -34,13 +34,12 @@
 from pyomo.contrib.doe.examples.reactor_kinetics import create_model, disc_for_measure
 from pyomo.opt import SolverFactory
 
-ipopt_available = SolverFactory('ipopt').available()
+ipopt_available = SolverFactory("ipopt").available()
 
 
-class Test_example_options(unittest.TestCase):
-    """Test the three options in the kinetics example."""
-
-    def test_setUP(self):
+class Test_Reaction_Kinetics_Example(unittest.TestCase):
+    def test_reaction_kinetics_create_model(self):
+        """Test the three options in the kinetics example."""
         # parmest option
         mod = create_model(model_option="parmest")
 
@@ -56,25 +55,125 @@ def test_setUP(self):
             create_model(model_option="stage2")
 
         with self.assertRaises(ValueError):
-            create_model(model_option="NotDefine")
+            create_model(model_option="NotDefined")
+
+    @unittest.skipIf(not ipopt_available, "The 'ipopt' solver is not available")
+    @unittest.skipIf(not numpy_available, "Numpy is not available")
+    @unittest.skipIf(not pandas_available, "Pandas is not available")
+    def test_kinetics_example_sequential_finite_then_optimize(self):
+        """Test the kinetics example with sequential_finite mode and then optimization"""
+        doe_object = self.specify_reaction_kinetics()
+
+        # Test FIM calculation at nominal values
+        sensi_opt = "sequential_finite"
+        result = doe_object.compute_FIM(
+            mode=sensi_opt, scale_nominal_param_value=True, formula="central"
+        )
+        result.result_analysis()
+        self.assertAlmostEqual(np.log10(result.trace), 2.7885, places=2)
+        self.assertAlmostEqual(np.log10(result.det), 2.8218, places=2)
+        self.assertAlmostEqual(np.log10(result.min_eig), -1.0123, places=2)
+
+        ### check subset feature
+        sub_name = "C"
+        sub_indices = {0: ["CB", "CC"], 1: [0.125, 0.25, 0.5, 0.75, 0.875]}
+
+        measure_subset = MeasurementVariables()
+        measure_subset.add_variables(
+            sub_name, indices=sub_indices, time_index_position=1
+        )
+        sub_result = result.subset(measure_subset)
+        sub_result.result_analysis()
+
+        self.assertAlmostEqual(np.log10(sub_result.trace), 2.5535, places=2)
+        self.assertAlmostEqual(np.log10(sub_result.det), 1.3464, places=2)
+        self.assertAlmostEqual(np.log10(sub_result.min_eig), -1.5386, places=2)
+
+        ### Test stochastic_program mode
+        #  Prior information (scaled FIM with T=500 and T=300 experiments)
+        prior = np.asarray(
+            [
+                [28.67892806, 5.41249739, -81.73674601, -24.02377324],
+                [5.41249739, 26.40935036, -12.41816477, -139.23992532],
+                [-81.73674601, -12.41816477, 240.46276004, 58.76422806],
+                [-24.02377324, -139.23992532, 58.76422806, 767.25584508],
+            ]
+        )
+        doe_object2 = self.specify_reaction_kinetics(prior=prior)
 
+        square_result, optimize_result = doe_object2.stochastic_program(
+            if_optimize=True,
+            if_Cholesky=True,
+            scale_nominal_param_value=True,
+            objective_option="det",
+            L_initial=np.linalg.cholesky(prior),
+            jac_initial=result.jaco_information.copy(),
+            tee_opt=True,
+        )
 
-class Test_doe_object(unittest.TestCase):
-    """Test the kinetics example with both the sequential_finite mode and the direct_kaug mode"""
+        optimize_result.result_analysis()
+        ## 2024-May-26: changing this to test the objective instead of the optimal solution
+        ## It's possible the objective is flat and the optimal solution is not unique
+        # self.assertAlmostEqual(value(optimize_result.model.CA0[0]), 5.0, places=2)
+        # self.assertAlmostEqual(value(optimize_result.model.T[0.5]), 300, places=2)
+        self.assertAlmostEqual(np.log10(optimize_result.det), 5.744, places=2)
+
+        square_result, optimize_result = doe_object2.stochastic_program(
+            if_optimize=True,
+            scale_nominal_param_value=True,
+            objective_option="trace",
+            jac_initial=result.jaco_information.copy(),
+            tee_opt=True,
+        )
+
+        optimize_result.result_analysis()
+        ## 2024-May-26: changing this to test the objective instead of the optimal solution
+        ## It's possible the objective is flat and the optimal solution is not unique
+        # self.assertAlmostEqual(value(optimize_result.model.CA0[0]), 5.0, places=2)
+        # self.assertAlmostEqual(value(optimize_result.model.T[0.5]), 300, places=2)
+        self.assertAlmostEqual(np.log10(optimize_result.trace), 3.340, places=2)
 
     @unittest.skipIf(not ipopt_available, "The 'ipopt' solver is not available")
     @unittest.skipIf(not numpy_available, "Numpy is not available")
     @unittest.skipIf(not pandas_available, "Pandas is not available")
-    def test_setUP(self):
+    def test_kinetics_example_direct_k_aug(self):
+        doe_object = self.specify_reaction_kinetics()
+
+        # Test FIM calculation at nominal values
+        sensi_opt = "direct_kaug"
+        result = doe_object.compute_FIM(
+            mode=sensi_opt, scale_nominal_param_value=True, formula="central"
+        )
+        result.result_analysis()
+        self.assertAlmostEqual(np.log10(result.trace), 2.789, places=2)
+        self.assertAlmostEqual(np.log10(result.det), 2.8247, places=2)
+        self.assertAlmostEqual(np.log10(result.min_eig), -1.0112, places=2)
+
+        ### check subset feature
+        sub_name = "C"
+        sub_indices = {0: ["CB", "CC"], 1: [0.125, 0.25, 0.5, 0.75, 0.875]}
+
+        measure_subset = MeasurementVariables()
+        measure_subset.add_variables(
+            sub_name, indices=sub_indices, time_index_position=1
+        )
+        sub_result = result.subset(measure_subset)
+        sub_result.result_analysis()
+
+        self.assertAlmostEqual(np.log10(sub_result.trace), 2.5535, places=2)
+        self.assertAlmostEqual(np.log10(sub_result.det), 1.3464, places=2)
+        self.assertAlmostEqual(np.log10(sub_result.min_eig), -1.5386, places=2)
+
+    def specify_reaction_kinetics(self, prior=None):
         ### Define inputs
         # Control time set [h]
         t_control = [0, 0.125, 0.25, 0.375, 0.5, 0.625, 0.75, 0.875, 1]
         # Define parameter nominal value
-        parameter_dict = {'A1': 84.79, 'A2': 371.72, 'E1': 7.78, 'E2': 15.05}
+        parameter_dict = {"A1": 84.79, "A2": 371.72, "E1": 7.78, "E2": 15.05}
 
         # measurement object
         variable_name = "C"
-        indices = {0: ['CA', 'CB', 'CC'], 1: t_control}
+        indices = {0: ["CA", "CB", "CC"], 1: t_control}
 
         measurements = MeasurementVariables()
         measurements.add_variables(
@@ -85,7 +184,7 @@ def test_setUP(self):
         exp_design = DesignVariables()
 
         # add CAO as design variable
-        var_C = 'CA0'
+        var_C = "CA0"
         indices_C = {0: [0]}
         exp1_C = [5]
         exp_design.add_variables(
@@ -98,7 +197,7 @@ def test_setUP(self):
         )
 
         # add T as design variable
-        var_T = 'T'
+        var_T = "T"
         indices_T = {0: t_control}
         exp1_T = [470, 300, 300, 300, 300, 300, 300, 300, 300]
 
@@ -111,9 +210,6 @@ def test_setUP(self):
             upper_bounds=700,
         )
 
-        ### Test sequential_finite mode
-        sensi_opt = "sequential_finite"
-
         design_names = exp_design.variable_names
         exp1 = [5, 570, 300, 300, 300, 300, 300, 300, 300, 300]
         exp1_design_dict = dict(zip(design_names, exp1))
@@ -126,95 +222,11 @@ def test_setUP(self):
             measurements,
             create_model,
             discretize_model=disc_for_measure,
-        )
-
-        result = doe_object.compute_FIM(
-            mode=sensi_opt, scale_nominal_param_value=True, formula="central"
-        )
-
-        result.result_analysis()
-
-        self.assertAlmostEqual(np.log10(result.trace), 2.7885, places=2)
-        self.assertAlmostEqual(np.log10(result.det), 2.8218, places=2)
-        self.assertAlmostEqual(np.log10(result.min_eig), -1.0123, places=2)
-
-        ### check subset feature
-        sub_name = "C"
-        sub_indices = {0: ["CB", "CC"], 1: [0.125, 0.25, 0.5, 0.75, 0.875]}
-
-        measure_subset = MeasurementVariables()
-        measure_subset.add_variables(
-            sub_name, indices=sub_indices, time_index_position=1
-        )
-        sub_result = result.subset(measure_subset)
-        sub_result.result_analysis()
-
-        self.assertAlmostEqual(np.log10(sub_result.trace), 2.5535, places=2)
-        self.assertAlmostEqual(np.log10(sub_result.det), 1.3464, places=2)
-        self.assertAlmostEqual(np.log10(sub_result.min_eig), -1.5386, places=2)
-
-        ### Test direct_kaug mode
-        sensi_opt = "direct_kaug"
-        # Define a new experiment
-
-        exp1 = [5, 570, 400, 300, 300, 300, 300, 300, 300, 300]
-        exp1_design_dict = dict(zip(design_names, exp1))
-        exp_design.update_values(exp1_design_dict)
-
-        doe_object = DesignOfExperiments(
-            parameter_dict,
-            exp_design,
-            measurements,
-            create_model,
-            discretize_model=disc_for_measure,
-        )
-
-        result = doe_object.compute_FIM(
-            mode=sensi_opt, scale_nominal_param_value=True, formula="central"
-        )
-
-        result.result_analysis()
-
-        self.assertAlmostEqual(np.log10(result.trace), 2.7211, places=2)
-        self.assertAlmostEqual(np.log10(result.det), 2.0845, places=2)
-        self.assertAlmostEqual(np.log10(result.min_eig), -1.3510, places=2)
-
-        ### Test stochastic_program mode
-
-        exp1 = [5, 570, 300, 300, 300, 300, 300, 300, 300, 300]
-        exp1_design_dict = dict(zip(design_names, exp1))
-        exp_design.update_values(exp1_design_dict)
-
-        # add a prior information (scaled FIM with T=500 and T=300 experiments)
-        prior = np.asarray(
-            [
-                [28.67892806, 5.41249739, -81.73674601, -24.02377324],
-                [5.41249739, 26.40935036, -12.41816477, -139.23992532],
-                [-81.73674601, -12.41816477, 240.46276004, 58.76422806],
-                [-24.02377324, -139.23992532, 58.76422806, 767.25584508],
-            ]
-        )
-
-        doe_object2 = DesignOfExperiments(
-            parameter_dict,
-            exp_design,
-            measurements,
-            create_model,
             prior_FIM=prior,
-            discretize_model=disc_for_measure,
-        )
-
-        square_result, optimize_result = doe_object2.stochastic_program(
-            if_optimize=True,
-            if_Cholesky=True,
-            scale_nominal_param_value=True,
-            objective_option="det",
-            L_initial=np.linalg.cholesky(prior),
         )
 
-        self.assertAlmostEqual(value(optimize_result.model.CA0[0]), 5.0, places=2)
-        self.assertAlmostEqual(value(optimize_result.model.T[0.5]), 300, places=2)
+        return doe_object
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     unittest.main()
diff --git a/pyomo/contrib/example/__init__.py b/pyomo/contrib/example/__init__.py
index 7f2d08a0292..c70b50e84de 100644
--- a/pyomo/contrib/example/__init__.py
+++ b/pyomo/contrib/example/__init__.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 #
 # import symbols and sub-packages
 #
diff --git a/pyomo/contrib/example/bar.py b/pyomo/contrib/example/bar.py
index 295540d3318..22e5c3997e9 100644
--- a/pyomo/contrib/example/bar.py
+++ b/pyomo/contrib/example/bar.py
@@ -1 +1,12 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 b = "1"
diff --git a/pyomo/contrib/example/foo.py b/pyomo/contrib/example/foo.py
index 1337a530cbc..f879bc70722 100644
--- a/pyomo/contrib/example/foo.py
+++ b/pyomo/contrib/example/foo.py
@@ -1 +1,12 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 a = 1
diff --git a/pyomo/contrib/example/plugins/__init__.py b/pyomo/contrib/example/plugins/__init__.py
index dc71adec9dc..179098bc18e 100644
--- a/pyomo/contrib/example/plugins/__init__.py
+++ b/pyomo/contrib/example/plugins/__init__.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # Define a 'load()' function, which simply imports
 # sub-packages that define plugin classes.
 
diff --git a/pyomo/contrib/example/plugins/ex_plugin.py b/pyomo/contrib/example/plugins/ex_plugin.py
index 504605205f4..7ee4c414ccf 100644
--- a/pyomo/contrib/example/plugins/ex_plugin.py
+++ b/pyomo/contrib/example/plugins/ex_plugin.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.core.base import Transformation, TransformationFactory
 
 
diff --git a/pyomo/contrib/example/tests/__init__.py b/pyomo/contrib/example/tests/__init__.py
index 5a1047f74ae..9c45a6ef8b6 100644
--- a/pyomo/contrib/example/tests/__init__.py
+++ b/pyomo/contrib/example/tests/__init__.py
@@ -1 +1,12 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # Tests for pyomo.contrib.example
diff --git a/pyomo/contrib/example/tests/test_example.py b/pyomo/contrib/example/tests/test_example.py
index c38de1b914f..55394f5d0c1 100644
--- a/pyomo/contrib/example/tests/test_example.py
+++ b/pyomo/contrib/example/tests/test_example.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/fbbt/__init__.py b/pyomo/contrib/fbbt/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/fbbt/__init__.py
+++ b/pyomo/contrib/fbbt/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/fbbt/expression_bounds_walker.py b/pyomo/contrib/fbbt/expression_bounds_walker.py
index 426d30f0ee6..cb287d54df5 100644
--- a/pyomo/contrib/fbbt/expression_bounds_walker.py
+++ b/pyomo/contrib/fbbt/expression_bounds_walker.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,9 +9,15 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
+import logging
 from math import pi
 from pyomo.common.collections import ComponentMap
 from pyomo.contrib.fbbt.interval import (
+    BoolFlag,
+    eq,
+    ineq,
+    ranged,
+    if_,
     add,
     acos,
     asin,
@@ -30,6 +36,7 @@
 )
 from pyomo.core.base.expression import Expression
 from pyomo.core.expr.numeric_expr import (
+    NumericExpression,
     NegationExpression,
     ProductExpression,
     DivisionExpression,
@@ -40,12 +47,20 @@
     LinearExpression,
     SumExpression,
     ExternalFunctionExpression,
+    Expr_ifExpression,
+)
+from pyomo.core.expr.logical_expr import BooleanExpression
+from pyomo.core.expr.relational_expr import (
+    EqualityExpression,
+    InequalityExpression,
+    RangedExpression,
 )
 from pyomo.core.expr.numvalue import native_numeric_types, native_types, value
 from pyomo.core.expr.visitor import StreamBasedExpressionVisitor
 from pyomo.repn.util import BeforeChildDispatcher, ExitNodeDispatcher
 
 inf = float('inf')
+logger = logging.getLogger(__name__)
 
 
 class ExpressionBoundsBeforeChildDispatcher(BeforeChildDispatcher):
@@ -60,6 +75,14 @@ def _before_external_function(visitor, child):
         # this then this should use them
         return False, (-inf, inf)
 
+    @staticmethod
+    def _before_native_numeric(visitor, child):
+        return False, (child, child)
+
+    @staticmethod
+    def _before_native_logical(visitor, child):
+        return False, (BoolFlag(child), BoolFlag(child))
+
     @staticmethod
     def _before_var(visitor, child):
         leaf_bounds = visitor.leaf_bounds
@@ -67,12 +90,15 @@ def _before_var(visitor, child):
             pass
         elif child.is_fixed() and visitor.use_fixed_var_values_as_bounds:
             val = child.value
-            if val is None:
+            try:
+                ans = visitor._before_child_handlers[val.__class__](visitor, val)
+            except ValueError:
                 raise ValueError(
                     "Var '%s' is fixed to None. This value cannot be used to "
                     "calculate bounds." % child.name
-                )
-            leaf_bounds[child] = (child.value, child.value)
+                ) from None
+            leaf_bounds[child] = ans[1]
+            return ans
         else:
             lb = child.lb
             ub = child.ub
@@ -93,23 +119,20 @@ def _before_named_expression(visitor, child):
 
     @staticmethod
     def _before_param(visitor, child):
-        return False, (child.value, child.value)
-
-    @staticmethod
-    def _before_native(visitor, child):
-        return False, (child, child)
+        val = child.value
+        return visitor._before_child_handlers[val.__class__](visitor, val)
 
     @staticmethod
     def _before_string(visitor, child):
         raise ValueError(
-            f"{child!r} ({type(child)}) is not a valid numeric type. "
+            f"{child!r} ({type(child).__name__}) is not a valid numeric type. "
             f"Cannot compute bounds on expression."
         )
 
     @staticmethod
     def _before_invalid(visitor, child):
         raise ValueError(
-            f"{child!r} ({type(child)}) is not a valid numeric type. "
+            f"{child!r} ({type(child).__name__}) is not a valid numeric type. "
             f"Cannot compute bounds on expression."
         )
 
@@ -123,10 +146,7 @@ def _before_complex(visitor, child):
     @staticmethod
     def _before_npv(visitor, child):
         val = value(child)
-        return False, (val, val)
-
-
-_before_child_handlers = ExpressionBoundsBeforeChildDispatcher()
+        return visitor._before_child_handlers[val.__class__](visitor, val)
 
 
 def _handle_ProductExpression(visitor, node, arg1, arg2):
@@ -207,6 +227,26 @@ def _handle_named_expression(visitor, node, arg):
     return arg
 
 
+def _handle_unknowable_bounds(visitor, node, arg):
+    return -inf, inf
+
+
+def _handle_equality(visitor, node, arg1, arg2):
+    return eq(*arg1, *arg2)
+
+
+def _handle_inequality(visitor, node, arg1, arg2):
+    return ineq(*arg1, *arg2)
+
+
+def _handle_ranged(visitor, node, arg1, arg2, arg3):
+    return ranged(*arg1, *arg2, *arg3)
+
+
+def _handle_expr_if(visitor, node, arg1, arg2, arg3):
+    return if_(*arg1, *arg2, *arg3)
+
+
 _unary_function_dispatcher = {
     'exp': _handle_exp,
     'log': _handle_log,
@@ -221,20 +261,20 @@ def _handle_named_expression(visitor, node, arg):
 }
 
 
-_operator_dispatcher = ExitNodeDispatcher(
-    {
-        ProductExpression: _handle_ProductExpression,
-        DivisionExpression: _handle_DivisionExpression,
-        PowExpression: _handle_PowExpression,
-        AbsExpression: _handle_AbsExpression,
-        SumExpression: _handle_SumExpression,
-        MonomialTermExpression: _handle_ProductExpression,
-        NegationExpression: _handle_NegationExpression,
-        UnaryFunctionExpression: _handle_UnaryFunctionExpression,
-        LinearExpression: _handle_SumExpression,
-        Expression: _handle_named_expression,
-    }
-)
+class ExpressionBoundsExitNodeDispatcher(ExitNodeDispatcher):
+    def unexpected_expression_type(self, visitor, node, *args):
+        if isinstance(node, NumericExpression):
+            ans = -inf, inf
+        elif isinstance(node, BooleanExpression):
+            ans = BoolFlag(False), BoolFlag(True)
+        else:
+            super().unexpected_expression_type(visitor, node, *args)
+        logger.warning(
+            f"Unexpected expression node type '{type(node).__name__}' "
+            f"found while walking expression tree; returning {ans} "
+            "for the expression bounds."
+        )
+        return ans
 
 
 class ExpressionBoundsVisitor(StreamBasedExpressionVisitor):
@@ -259,6 +299,27 @@ class ExpressionBoundsVisitor(StreamBasedExpressionVisitor):
         the computed bounds should be valid.
     """
 
+    _before_child_handlers = ExpressionBoundsBeforeChildDispatcher()
+    _operator_dispatcher = ExpressionBoundsExitNodeDispatcher(
+        {
+            ProductExpression: _handle_ProductExpression,
+            DivisionExpression: _handle_DivisionExpression,
+            PowExpression: _handle_PowExpression,
+            AbsExpression: _handle_AbsExpression,
+            SumExpression: _handle_SumExpression,
+            MonomialTermExpression: _handle_ProductExpression,
+            NegationExpression: _handle_NegationExpression,
+            UnaryFunctionExpression: _handle_UnaryFunctionExpression,
+            LinearExpression: _handle_SumExpression,
+            Expression: _handle_named_expression,
+            ExternalFunctionExpression: _handle_unknowable_bounds,
+            EqualityExpression: _handle_equality,
+            InequalityExpression: _handle_inequality,
+            RangedExpression: _handle_ranged,
+            Expr_ifExpression: _handle_expr_if,
+        }
+    )
+
     def __init__(
         self,
         leaf_bounds=None,
@@ -277,7 +338,7 @@ def initializeWalker(self, expr):
         return True, expr
 
     def beforeChild(self, node, child, child_idx):
-        return _before_child_handlers[child.__class__](self, child)
+        return self._before_child_handlers[child.__class__](self, child)
 
     def exitNode(self, node, data):
-        return _operator_dispatcher[node.__class__](self, node, *data)
+        return self._operator_dispatcher[node.__class__](self, node, *data)
diff --git a/pyomo/contrib/fbbt/fbbt.py b/pyomo/contrib/fbbt/fbbt.py
index bf42cbe7f33..1507c4a3cc5 100644
--- a/pyomo/contrib/fbbt/fbbt.py
+++ b/pyomo/contrib/fbbt/fbbt.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -24,9 +24,10 @@
 import math
 from pyomo.core.base.block import Block
 from pyomo.core.base.constraint import Constraint
+from pyomo.core.base.expression import ExpressionData, ScalarExpression
+from pyomo.core.base.objective import ObjectiveData, ScalarObjective
 from pyomo.core.base.var import Var
 from pyomo.gdp import Disjunct
-from pyomo.core.base.expression import _GeneralExpressionData, ScalarExpression
 import logging
 from pyomo.common.errors import InfeasibleConstraintException, PyomoException
 from pyomo.common.config import (
@@ -333,15 +334,15 @@ def _prop_bnds_leaf_to_root_UnaryFunctionExpression(visitor, node, arg):
     _unary_leaf_to_root_map[node.getname()](visitor, node, arg)
 
 
-def _prop_bnds_leaf_to_root_GeneralExpression(visitor, node, expr):
+def _prop_bnds_leaf_to_root_NamedExpression(visitor, node, expr):
     """
     Propagate bounds from children to parent
 
     Parameters
     ----------
     visitor: _FBBTVisitorLeafToRoot
-    node: pyomo.core.base.expression._GeneralExpressionData
-    expr: GeneralExpression arg
+    node: pyomo.core.base.expression.NamedExpressionData
+    expr: NamedExpressionData arg
     """
     bnds_dict = visitor.bnds_dict
     if node in bnds_dict:
@@ -366,8 +367,10 @@ def _prop_bnds_leaf_to_root_GeneralExpression(visitor, node, expr):
         numeric_expr.UnaryFunctionExpression: _prop_bnds_leaf_to_root_UnaryFunctionExpression,
         numeric_expr.LinearExpression: _prop_bnds_leaf_to_root_SumExpression,
         numeric_expr.AbsExpression: _prop_bnds_leaf_to_root_abs,
-        _GeneralExpressionData: _prop_bnds_leaf_to_root_GeneralExpression,
-        ScalarExpression: _prop_bnds_leaf_to_root_GeneralExpression,
+        ExpressionData: _prop_bnds_leaf_to_root_NamedExpression,
+        ScalarExpression: _prop_bnds_leaf_to_root_NamedExpression,
+        ObjectiveData: _prop_bnds_leaf_to_root_NamedExpression,
+        ScalarObjective: _prop_bnds_leaf_to_root_NamedExpression,
     },
 )
 
@@ -898,13 +901,13 @@ def _prop_bnds_root_to_leaf_UnaryFunctionExpression(node, bnds_dict, feasibility
         )
 
 
-def _prop_bnds_root_to_leaf_GeneralExpression(node, bnds_dict, feasibility_tol):
+def _prop_bnds_root_to_leaf_NamedExpression(node, bnds_dict, feasibility_tol):
     """
     Propagate bounds from parent to children.
 
     Parameters
     ----------
-    node: pyomo.core.base.expression._GeneralExpressionData
+    node: pyomo.core.base.expression.NamedExpressionData
     bnds_dict: ComponentMap
     feasibility_tol: float
         If the bounds computed on the body of a constraint violate the bounds of the constraint by more than
@@ -945,12 +948,10 @@ def _prop_bnds_root_to_leaf_GeneralExpression(node, bnds_dict, feasibility_tol):
 )
 _prop_bnds_root_to_leaf_map[numeric_expr.AbsExpression] = _prop_bnds_root_to_leaf_abs
 
-_prop_bnds_root_to_leaf_map[_GeneralExpressionData] = (
-    _prop_bnds_root_to_leaf_GeneralExpression
-)
-_prop_bnds_root_to_leaf_map[ScalarExpression] = (
-    _prop_bnds_root_to_leaf_GeneralExpression
-)
+_prop_bnds_root_to_leaf_map[ExpressionData] = _prop_bnds_root_to_leaf_NamedExpression
+_prop_bnds_root_to_leaf_map[ScalarExpression] = _prop_bnds_root_to_leaf_NamedExpression
+_prop_bnds_root_to_leaf_map[ObjectiveData] = _prop_bnds_root_to_leaf_NamedExpression
+_prop_bnds_root_to_leaf_map[ScalarObjective] = _prop_bnds_root_to_leaf_NamedExpression
 
 
 def _check_and_reset_bounds(var, lb, ub):
diff --git a/pyomo/contrib/fbbt/interval.py b/pyomo/contrib/fbbt/interval.py
index fd86af4c106..a12d1a4529f 100644
--- a/pyomo/contrib/fbbt/interval.py
+++ b/pyomo/contrib/fbbt/interval.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -17,6 +17,119 @@
 inf = float('inf')
 
 
+class _bool_flag(object):
+    def __init__(self, val):
+        self._val = val
+
+    def __bool__(self):
+        return self._val
+
+    def _op(self, *others):
+        raise ValueError(
+            f"{self._val!r} ({type(self._val).__name__}) is not a valid numeric type. "
+            f"Cannot compute bounds on expression."
+        )
+
+    def __repr__(self):
+        return repr(self._val)
+
+    __float__ = _op
+    __int__ = _op
+    __abs__ = _op
+    __neg__ = _op
+    __add__ = _op
+    __sub__ = _op
+    __mul__ = _op
+    __div__ = _op
+    __pow__ = _op
+    __radd__ = _op
+    __rsub__ = _op
+    __rmul__ = _op
+    __rdiv__ = _op
+    __rpow__ = _op
+
+
+_true = _bool_flag(True)
+_false = _bool_flag(False)
+
+
+def BoolFlag(val):
+    return _true if val else _false
+
+
+def ineq(xl, xu, yl, yu):
+    """Compute the "bounds" on an InequalityExpression
+
+    Note this is *not* performing interval arithmetic: we are
+    calculating the "bounds" on a RelationalExpression (whose domain is
+    {True, False}).  Therefore we are determining if `x` can be less
+    than `y`, `x` can not be less than `y`, or both.
+
+    """
+    ans = []
+    if yl < xu:
+        ans.append(_false)
+    if xl <= yu:
+        ans.append(_true)
+    assert ans
+    if len(ans) == 1:
+        ans.append(ans[0])
+    return tuple(ans)
+
+
+def eq(xl, xu, yl, yu):
+    """Compute the "bounds" on an EqualityExpression
+
+    Note this is *not* performing interval arithmetic: we are
+    calculating the "bounds" on a RelationalExpression (whose domain is
+    {True, False}).  Therefore we are determining if `x` can be equal to
+    `y`, `x` can not be equal to `y`, or both.
+
+    """
+    ans = []
+    if xl != xu or yl != yu or xl != yl:
+        ans.append(_false)
+    if xl <= yu and yl <= xu:
+        ans.append(_true)
+    assert ans
+    if len(ans) == 1:
+        ans.append(ans[0])
+    return tuple(ans)
+
+
+def ranged(xl, xu, yl, yu, zl, zu):
+    """Compute the "bounds" on a RangedExpression
+
+    Note this is *not* performing interval arithmetic: we are
+    calculating the "bounds" on a RelationalExpression (whose domain is
+    {True, False}).  Therefore we are determining if `y` can be between
+    `z` and `z`, `y` can be outside the range `x` and `z`, or both.
+
+    """
+    lb = ineq(xl, xu, yl, yu)
+    ub = ineq(yl, yu, zl, zu)
+    ans = []
+    if not lb[0] or not ub[0]:
+        ans.append(_false)
+    if lb[1] and ub[1]:
+        ans.append(_true)
+    if len(ans) == 1:
+        ans.append(ans[0])
+    return tuple(ans)
+
+
+def if_(il, iu, tl, tu, fl, fu):
+    l = []
+    u = []
+    if iu:
+        l.append(tl)
+        u.append(tu)
+    if not il:
+        l.append(fl)
+        u.append(fu)
+    return min(l), max(u)
+
+
 def add(xl, xu, yl, yu):
     return xl + yl, xu + yu
 
@@ -39,12 +152,18 @@ def mul(xl, xu, yl, yu):
 
 
 def inv(xl, xu, feasibility_tol):
-    """
-    The case where xl is very slightly positive but should be very slightly negative (or xu is very slightly negative
-    but should be very slightly positive) should not be an issue. Suppose xu is 2 and xl is 1e-15 but should be -1e-15.
-    The bounds obtained from this function will be [0.5, 1e15] or [0.5, inf), depending on the value of
-    feasibility_tol. The true bounds are (-inf, -1e15] U [0.5, inf), where U is union. The exclusion of (-inf, -1e15]
-    should be acceptable. Additionally, it very important to return a non-negative interval when xl is non-negative.
+    """Compute the inverse of an interval
+
+    The case where xl is very slightly positive but should be very
+    slightly negative (or xu is very slightly negative but should be
+    very slightly positive) should not be an issue. Suppose xu is 2 and
+    xl is 1e-15 but should be -1e-15.  The bounds obtained from this
+    function will be [0.5, 1e15] or [0.5, inf), depending on the value
+    of feasibility_tol. The true bounds are (-inf, -1e15] U [0.5, inf),
+    where U is union. The exclusion of (-inf, -1e15] should be
+    acceptable. Additionally, it very important to return a non-negative
+    interval when xl is non-negative.
+
     """
     if xu - xl <= -feasibility_tol:
         raise InfeasibleConstraintException(
@@ -89,9 +208,8 @@ def power(xl, xu, yl, yu, feasibility_tol):
     Compute bounds on x**y.
     """
     if xl > 0:
-        """
-        If x is always positive, things are simple. We only need to worry about the sign of y.
-        """
+        # If x is always positive, things are simple. We only need to
+        # worry about the sign of y.
         if yl < 0 < yu:
             lb = min(xu**yl, xl**yu)
             ub = max(xl**yl, xu**yu)
@@ -181,14 +299,15 @@ def power(xl, xu, yl, yu, feasibility_tol):
 
 
 def _inverse_power1(zl, zu, yl, yu, orig_xl, orig_xu, feasibility_tol):
-    """
-    z = x**y => compute bounds on x.
+    """z = x**y => compute bounds on x.
 
     First, start by computing bounds on x with
 
         x = exp(ln(z) / y)
 
-    However, if y is an integer, then x can be negative, so there are several special cases. See the docs below.
+    However, if y is an integer, then x can be negative, so there are
+    several special cases. See the docs below.
+
     """
     xl, xu = log(zl, zu)
     xl, xu = div(xl, xu, yl, yu, feasibility_tol)
@@ -199,22 +318,31 @@ def _inverse_power1(zl, zu, yl, yu, orig_xl, orig_xu, feasibility_tol):
         y = yl
         if y == 0:
             # Anything to the power of 0 is 1, so if y is 0, then x can be anything
-            # (assuming zl <= 1 <= zu, which is enforced when traversing the tree in the other direction)
+            # (assuming zl <= 1 <= zu, which is enforced when traversing
+            # the tree in the other direction)
             xl = -inf
             xu = inf
         elif y % 2 == 0:
-            """
-            if y is even, then there are two primary cases (note that it is much easier to walk through these
-            while looking at plots):
+            """if y is even, then there are two primary cases (note that it is much
+            easier to walk through these while looking at plots):
+
             case 1: y is positive
-                x**y is convex, positive, and symmetric. The bounds on x depend on the lower bound of z. If zl <= 0,
-                then xl should simply be -xu. However, if zl > 0, then we may be able to say something better. For
-                example, if the original lower bound on x is positive, then we can keep xl computed from
-                x = exp(ln(z) / y). Furthermore, if the original lower bound on x is larger than -xl computed from
-                x = exp(ln(z) / y), then we can still keep the xl computed from x = exp(ln(z) / y). Similar logic
-                applies to the upper bound of x.
+
+                x**y is convex, positive, and symmetric. The bounds on x
+                depend on the lower bound of z. If zl <= 0, then xl
+                should simply be -xu. However, if zl > 0, then we may be
+                able to say something better. For example, if the
+                original lower bound on x is positive, then we can keep
+                xl computed from x = exp(ln(z) / y). Furthermore, if the
+                original lower bound on x is larger than -xl computed
+                from x = exp(ln(z) / y), then we can still keep the xl
+                computed from x = exp(ln(z) / y). Similar logic applies
+                to the upper bound of x.
+
             case 2: y is negative
+
                 The ideas are similar to case 1.
+
             """
             if zu + feasibility_tol < 0:
                 raise InfeasibleConstraintException(
@@ -262,16 +390,25 @@ def _inverse_power1(zl, zu, yl, yu, orig_xl, orig_xu, feasibility_tol):
                 xl = _xl
                 xu = _xu
         else:  # y % 2 == 1
-            """
-            y is odd.
+            """y is odd.
+
             Case 1: y is positive
-                x**y is monotonically increasing. If y is positive, then we can can compute the bounds on x using
-                x = z**(1/y) and the signs on xl and xu depend on the signs of zl and zu.
+
+                x**y is monotonically increasing. If y is positive, then
+                we can can compute the bounds on x using x = z**(1/y)
+                and the signs on xl and xu depend on the signs of zl and
+                zu.
+
             Case 2: y is negative
-                Again, this is easier to visualize with a plot. x**y approaches zero when x approaches -inf or inf.
-                Thus, if zl < 0 < zu, then no bounds can be inferred for x. If z is positive (zl >=0 ) then we can
-                use the bounds computed from x = exp(ln(z) / y). If z is negative (zu <= 0), then we live in the
-                bottom left quadrant, xl depends on zu, and xu depends on zl.
+
+                Again, this is easier to visualize with a plot. x**y
+                approaches zero when x approaches -inf or inf.  Thus, if
+                zl < 0 < zu, then no bounds can be inferred for x. If z
+                is positive (zl >=0 ) then we can use the bounds
+                computed from x = exp(ln(z) / y). If z is negative (zu
+                <= 0), then we live in the bottom left quadrant, xl
+                depends on zu, and xu depends on zl.
+
             """
             if y > 0:
                 xl = abs(zl) ** (1.0 / y)
@@ -298,12 +435,13 @@ def _inverse_power1(zl, zu, yl, yu, orig_xl, orig_xu, feasibility_tol):
 
 
 def _inverse_power2(zl, zu, xl, xu, feasiblity_tol):
-    """
-    z = x**y => compute bounds on y
+    """z = x**y => compute bounds on y
     y = ln(z) / ln(x)
 
-    This function assumes the exponent can be fractional, so x must be positive. This method should not be called
-    if the exponent is an integer.
+    This function assumes the exponent can be fractional, so x must be
+    positive. This method should not be called if the exponent is an
+    integer.
+
     """
     if xu <= 0:
         raise IntervalException(
@@ -391,10 +529,12 @@ def sin(xl, xu):
     ub: float
     """
 
-    # if there is a minimum between xl and xu, then the lower bound is -1. Minimums occur at 2*pi*n - pi/2
-    # find the minimum value of i such that 2*pi*i - pi/2 >= xl. Then round i up. If 2*pi*i - pi/2 is still less
-    # than or equal to xu, then there is a minimum between xl and xu. Thus the lb is -1. Otherwise, the minimum
-    # occurs at either xl or xu
+    # if there is a minimum between xl and xu, then the lower bound is
+    # -1. Minimums occur at 2*pi*n - pi/2 find the minimum value of i
+    # such that 2*pi*i - pi/2 >= xl. Then round i up. If 2*pi*i - pi/2
+    # is still less than or equal to xu, then there is a minimum between
+    # xl and xu. Thus the lb is -1. Otherwise, the minimum occurs at
+    # either xl or xu
     if xl <= -inf or xu >= inf:
         return -1, 1
     pi = math.pi
@@ -406,7 +546,8 @@ def sin(xl, xu):
     else:
         lb = min(math.sin(xl), math.sin(xu))
 
-    # if there is a maximum between xl and xu, then the upper bound is 1. Maximums occur at 2*pi*n + pi/2
+    # if there is a maximum between xl and xu, then the upper bound is
+    # 1. Maximums occur at 2*pi*n + pi/2
     i = (xu - pi / 2) / (2 * pi)
     i = math.floor(i)
     x_at_max = 2 * pi * i + pi / 2
@@ -432,10 +573,12 @@ def cos(xl, xu):
     ub: float
     """
 
-    # if there is a minimum between xl and xu, then the lower bound is -1. Minimums occur at 2*pi*n - pi
-    # find the minimum value of i such that 2*pi*i - pi >= xl. Then round i up. If 2*pi*i - pi/2 is still less
-    # than or equal to xu, then there is a minimum between xl and xu. Thus the lb is -1. Otherwise, the minimum
-    # occurs at either xl or xu
+    # if there is a minimum between xl and xu, then the lower bound is
+    # -1. Minimums occur at 2*pi*n - pi find the minimum value of i such
+    # that 2*pi*i - pi >= xl. Then round i up. If 2*pi*i - pi/2 is still
+    # less than or equal to xu, then there is a minimum between xl and
+    # xu. Thus the lb is -1. Otherwise, the minimum occurs at either xl
+    # or xu
     if xl <= -inf or xu >= inf:
         return -1, 1
     pi = math.pi
@@ -447,7 +590,8 @@ def cos(xl, xu):
     else:
         lb = min(math.cos(xl), math.cos(xu))
 
-    # if there is a maximum between xl and xu, then the upper bound is 1. Maximums occur at 2*pi*n
+    # if there is a maximum between xl and xu, then the upper bound is
+    # 1. Maximums occur at 2*pi*n
     i = (xu) / (2 * pi)
     i = math.floor(i)
     x_at_max = 2 * pi * i
@@ -473,10 +617,12 @@ def tan(xl, xu):
     ub: float
     """
 
-    # tan goes to -inf and inf at every pi*i + pi/2 (integer i). If one of these values is between xl and xu, then
-    # the lb is -inf and the ub is inf. Otherwise the minimum occurs at xl and the maximum occurs at xu.
-    # find the minimum value of i such that pi*i + pi/2 >= xl. Then round i up. If pi*i + pi/2 is still less
-    # than or equal to xu, then there is an undefined point between xl and xu.
+    # tan goes to -inf and inf at every pi*i + pi/2 (integer i). If one
+    # of these values is between xl and xu, then the lb is -inf and the
+    # ub is inf. Otherwise the minimum occurs at xl and the maximum
+    # occurs at xu.  find the minimum value of i such that pi*i + pi/2
+    # >= xl. Then round i up. If pi*i + pi/2 is still less than or equal
+    # to xu, then there is an undefined point between xl and xu.
     if xl <= -inf or xu >= inf:
         return -inf, inf
     pi = math.pi
@@ -520,12 +666,12 @@ def asin(xl, xu, yl, yu, feasibility_tol):
     if yl <= -inf:
         lb = yl
     elif xl <= math.sin(yl) <= xu:
-        # if sin(yl) >= xl then yl satisfies the bounds on x, and the lower bound of y cannot be improved
+        # if sin(yl) >= xl then yl satisfies the bounds on x, and the
+        # lower bound of y cannot be improved
         lb = yl
     elif math.sin(yl) < xl:
-        """
-        we can only push yl up from its current value to the next lowest value such that xl = sin(y). In other words,
-        we need to
+        """we can only push yl up from its current value to the next lowest
+        value such that xl = sin(y). In other words, we need to
 
         min y
         s.t.
@@ -533,19 +679,21 @@ def asin(xl, xu, yl, yu, feasibility_tol):
             y >= yl
 
         globally.
+
         """
-        # first find the next minimum of x = sin(y). Minimums occur at y = 2*pi*n - pi/2 for integer n.
+        # first find the next minimum of x = sin(y). Minimums occur at y
+        # = 2*pi*n - pi/2 for integer n.
         i = (yl + pi / 2) / (2 * pi)
         i1 = math.floor(i)
         i2 = math.ceil(i)
         i1 = 2 * pi * i1 - pi / 2
         i2 = 2 * pi * i2 - pi / 2
-        # now find the next value of y such that xl = sin(y). This can be computed by a distance from the minimum (i).
+        # now find the next value of y such that xl = sin(y). This can
+        # be computed by a distance from the minimum (i).
         y_tmp = math.asin(xl)  # this will give me a value between -pi/2 and pi/2
-        dist = y_tmp - (
-            -pi / 2
-        )  # this is the distance between the minimum of the sin function and a value that
-        # satisfies xl = sin(y)
+        dist = y_tmp - (-pi / 2)
+        # this is the distance between the minimum of the sin function
+        # and a value that satisfies xl = sin(y)
         lb1 = i1 + dist
         lb2 = i2 + dist
         if lb1 >= yl - feasibility_tol:
@@ -633,12 +781,12 @@ def acos(xl, xu, yl, yu, feasibility_tol):
     if yl <= -inf:
         lb = yl
     elif xl <= math.cos(yl) <= xu:
-        # if xl <= cos(yl) <= xu then yl satisfies the bounds on x, and the lower bound of y cannot be improved
+        # if xl <= cos(yl) <= xu then yl satisfies the bounds on x, and
+        # the lower bound of y cannot be improved
         lb = yl
     elif math.cos(yl) < xl:
-        """
-        we can only push yl up from its current value to the next lowest value such that xl = cos(y). In other words,
-        we need to
+        """we can only push yl up from its current value to the next lowest
+        value such that xl = cos(y). In other words, we need to
 
         min y
         s.t.
@@ -646,19 +794,21 @@ def acos(xl, xu, yl, yu, feasibility_tol):
             y >= yl
 
         globally.
+
         """
-        # first find the next minimum of x = cos(y). Minimums occur at y = 2*pi*n - pi for integer n.
+        # first find the next minimum of x = cos(y). Minimums occur at y
+        # = 2*pi*n - pi for integer n.
         i = (yl + pi) / (2 * pi)
         i1 = math.floor(i)
         i2 = math.ceil(i)
         i1 = 2 * pi * i1 - pi
         i2 = 2 * pi * i2 - pi
-        # now find the next value of y such that xl = cos(y). This can be computed by a distance from the minimum (i).
+        # now find the next value of y such that xl = cos(y). This can
+        # be computed by a distance from the minimum (i).
         y_tmp = math.acos(xl)  # this will give me a value between 0 and pi
-        dist = (
-            pi - y_tmp
-        )  # this is the distance between the minimum of the sin function and a value that
-        # satisfies xl = sin(y)
+        dist = pi - y_tmp
+        # this is the distance between the minimum of the sin function
+        # and a value that satisfies xl = sin(y)
         lb1 = i1 + dist
         lb2 = i2 + dist
         if lb1 >= yl - feasibility_tol:
diff --git a/pyomo/contrib/fbbt/tests/__init__.py b/pyomo/contrib/fbbt/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/fbbt/tests/__init__.py
+++ b/pyomo/contrib/fbbt/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/fbbt/tests/test_expression_bounds_walker.py b/pyomo/contrib/fbbt/tests/test_expression_bounds_walker.py
index c51230155a7..5d27a2e4087 100644
--- a/pyomo/contrib/fbbt/tests/test_expression_bounds_walker.py
+++ b/pyomo/contrib/fbbt/tests/test_expression_bounds_walker.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -10,10 +10,33 @@
 #  ___________________________________________________________________________
 
 import math
-from pyomo.environ import exp, log, log10, sin, cos, tan, asin, acos, atan, sqrt
 import pyomo.common.unittest as unittest
-from pyomo.contrib.fbbt.expression_bounds_walker import ExpressionBoundsVisitor
-from pyomo.core import Any, ConcreteModel, Expression, Param, Var
+
+from pyomo.environ import (
+    exp,
+    log,
+    log10,
+    sin,
+    cos,
+    tan,
+    asin,
+    acos,
+    atan,
+    sqrt,
+    inequality,
+    Expr_if,
+    Any,
+    ConcreteModel,
+    Expression,
+    Param,
+    Var,
+)
+
+from pyomo.common.errors import DeveloperError
+from pyomo.common.log import LoggingIntercept
+from pyomo.contrib.fbbt.expression_bounds_walker import ExpressionBoundsVisitor, inf
+from pyomo.contrib.fbbt.interval import _true, _false
+from pyomo.core.expr import ExpressionBase, NumericExpression, BooleanExpression
 
 
 class TestExpressionBoundsWalker(unittest.TestCase):
@@ -273,11 +296,19 @@ def test_npv_expression(self):
 
     def test_invalid_numeric_type(self):
         m = self.make_model()
-        m.p = Param(initialize=True, domain=Any)
+        m.p = Param(initialize=True, mutable=True, domain=Any)
         visitor = ExpressionBoundsVisitor()
         with self.assertRaisesRegex(
             ValueError,
-            r"True \(<class 'bool'>\) is not a valid numeric type. "
+            r"True \(bool\) is not a valid numeric type. "
+            r"Cannot compute bounds on expression.",
+        ):
+            lb, ub = visitor.walk_expression(m.p + m.y)
+
+        m.p.set_value(None)
+        with self.assertRaisesRegex(
+            ValueError,
+            r"None \(NoneType\) is not a valid numeric type. "
             r"Cannot compute bounds on expression.",
         ):
             lb, ub = visitor.walk_expression(m.p + m.y)
@@ -288,7 +319,7 @@ def test_invalid_string(self):
         visitor = ExpressionBoundsVisitor()
         with self.assertRaisesRegex(
             ValueError,
-            r"'True' \(<class 'str'>\) is not a valid numeric type. "
+            r"'True' \(str\) is not a valid numeric type. "
             r"Cannot compute bounds on expression.",
         ):
             lb, ub = visitor.walk_expression(m.p + m.y)
@@ -303,3 +334,82 @@ def test_invalid_complex(self):
             r"complex numbers. Encountered when processing \(4\+5j\)",
         ):
             lb, ub = visitor.walk_expression(m.p + m.y)
+
+    def test_inequality(self):
+        m = self.make_model()
+        visitor = ExpressionBoundsVisitor()
+        self.assertEqual(visitor.walk_expression(m.z <= m.y), (_true, _true))
+        self.assertEqual(visitor.walk_expression(m.y <= m.z), (_false, _false))
+        self.assertEqual(visitor.walk_expression(m.y <= m.x), (_false, _true))
+
+    def test_equality(self):
+        m = self.make_model()
+        m.p = Param(initialize=5)
+        visitor = ExpressionBoundsVisitor()
+        self.assertEqual(visitor.walk_expression(m.y == m.z), (_false, _false))
+        self.assertEqual(visitor.walk_expression(m.y == m.x), (_false, _true))
+        self.assertEqual(visitor.walk_expression(m.p == m.p), (_true, _true))
+
+    def test_ranged(self):
+        m = self.make_model()
+        visitor = ExpressionBoundsVisitor()
+        self.assertEqual(
+            visitor.walk_expression(inequality(m.z, m.y, 5)), (_true, _true)
+        )
+        self.assertEqual(
+            visitor.walk_expression(inequality(m.y, m.z, m.y)), (_false, _false)
+        )
+        self.assertEqual(
+            visitor.walk_expression(inequality(m.y, m.x, m.y)), (_false, _true)
+        )
+
+    def test_expr_if(self):
+        m = self.make_model()
+        visitor = ExpressionBoundsVisitor()
+        self.assertEqual(
+            visitor.walk_expression(Expr_if(IF=m.z <= m.y, THEN=m.z, ELSE=m.y)),
+            m.z.bounds,
+        )
+        self.assertEqual(
+            visitor.walk_expression(Expr_if(IF=m.z >= m.y, THEN=m.z, ELSE=m.y)),
+            m.y.bounds,
+        )
+        self.assertEqual(
+            visitor.walk_expression(Expr_if(IF=m.y <= m.x, THEN=m.y, ELSE=m.x)), (-2, 5)
+        )
+
+    def test_unknown_classes(self):
+        class UnknownNumeric(NumericExpression):
+            pass
+
+        class UnknownLogic(BooleanExpression):
+            def nargs(self):
+                return 0
+
+        class UnknownOther(ExpressionBase):
+            @property
+            def args(self):
+                return ()
+
+            def nargs(self):
+                return 0
+
+        visitor = ExpressionBoundsVisitor()
+        with LoggingIntercept() as LOG:
+            self.assertEqual(visitor.walk_expression(UnknownNumeric(())), (-inf, inf))
+        self.assertEqual(
+            LOG.getvalue(),
+            "Unexpected expression node type 'UnknownNumeric' found while walking "
+            "expression tree; returning (-inf, inf) for the expression bounds.\n",
+        )
+        with LoggingIntercept() as LOG:
+            self.assertEqual(visitor.walk_expression(UnknownLogic(())), (_false, _true))
+        self.assertEqual(
+            LOG.getvalue(),
+            "Unexpected expression node type 'UnknownLogic' found while walking "
+            "expression tree; returning (False, True) for the expression bounds.\n",
+        )
+        with self.assertRaisesRegex(
+            DeveloperError, "Unexpected expression node type 'UnknownOther' found"
+        ):
+            visitor.walk_expression(UnknownOther())
diff --git a/pyomo/contrib/fbbt/tests/test_fbbt.py b/pyomo/contrib/fbbt/tests/test_fbbt.py
index 5e8d656eeab..f7d08d11215 100644
--- a/pyomo/contrib/fbbt/tests/test_fbbt.py
+++ b/pyomo/contrib/fbbt/tests/test_fbbt.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/fbbt/tests/test_interval.py b/pyomo/contrib/fbbt/tests/test_interval.py
index 59c62be4e84..1e42162a35e 100644
--- a/pyomo/contrib/fbbt/tests/test_interval.py
+++ b/pyomo/contrib/fbbt/tests/test_interval.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import math
 import pyomo.common.unittest as unittest
 from pyomo.common.dependencies import numpy as np, numpy_available
diff --git a/pyomo/contrib/fme/__init__.py b/pyomo/contrib/fme/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/fme/__init__.py
+++ b/pyomo/contrib/fme/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/fme/fourier_motzkin_elimination.py b/pyomo/contrib/fme/fourier_motzkin_elimination.py
index 18aa157545e..4636450c58e 100644
--- a/pyomo/contrib/fme/fourier_motzkin_elimination.py
+++ b/pyomo/contrib/fme/fourier_motzkin_elimination.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -23,7 +23,7 @@
     value,
     ConstraintList,
 )
-from pyomo.core.base import TransformationFactory, _VarData
+from pyomo.core.base import TransformationFactory, VarData
 from pyomo.core.plugins.transform.hierarchy import Transformation
 from pyomo.common.config import ConfigBlock, ConfigValue, NonNegativeFloat
 from pyomo.common.modeling import unique_component_name
@@ -58,7 +58,7 @@ def _check_var_bounds_filter(constraint):
 
 
 def vars_to_eliminate_list(x):
-    if isinstance(x, (Var, _VarData)):
+    if isinstance(x, (Var, VarData)):
         if not x.is_indexed():
             return ComponentSet([x])
         ans = ComponentSet()
diff --git a/pyomo/contrib/fme/plugins.py b/pyomo/contrib/fme/plugins.py
index 324dd583d0f..b8278ccbb27 100644
--- a/pyomo/contrib/fme/plugins.py
+++ b/pyomo/contrib/fme/plugins.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/fme/tests/__init__.py b/pyomo/contrib/fme/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/fme/tests/__init__.py
+++ b/pyomo/contrib/fme/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/fme/tests/test_fourier_motzkin_elimination.py b/pyomo/contrib/fme/tests/test_fourier_motzkin_elimination.py
index 11c008acf82..dc721488f74 100644
--- a/pyomo/contrib/fme/tests/test_fourier_motzkin_elimination.py
+++ b/pyomo/contrib/fme/tests/test_fourier_motzkin_elimination.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -435,7 +435,7 @@ def check_hull_projected_constraints(self, m, constraints, indices):
         self.assertIs(body.linear_vars[2], m.startup.binary_indicator_var)
         self.assertEqual(body.linear_coefs[2], 2)
 
-        # 1 <= time1_disjuncts[0].ind_var + time_1.disjuncts[1].ind_var
+        # 1 <= time1_disjuncts[0].ind_var + time1_disjuncts[1].ind_var
         cons = constraints[indices[7]]
         self.assertEqual(cons.lower, 1)
         self.assertIsNone(cons.upper)
@@ -548,12 +548,12 @@ def test_project_disaggregated_vars(self):
         # we of course get tremendous amounts of garbage, but we make sure that
         # what should be here is:
         self.check_hull_projected_constraints(
-            m, constraints, [23, 19, 8, 10, 54, 67, 35, 3, 4, 1, 2]
+            m, constraints, [16, 12, 69, 71, 47, 60, 28, 1, 2, 3, 4]
         )
         # and when we filter, it's still there.
         constraints = filtered._pyomo_contrib_fme_transformation.projected_constraints
         self.check_hull_projected_constraints(
-            filtered, constraints, [10, 8, 5, 6, 15, 19, 11, 3, 4, 1, 2]
+            filtered, constraints, [8, 6, 20, 21, 13, 17, 9, 1, 2, 3, 4]
         )
 
     @unittest.skipIf(not 'glpk' in solvers, 'glpk not available')
@@ -570,7 +570,7 @@ def test_post_processing(self):
         # They should be the same as the above, but now these are *all* the
         # constraints
         self.check_hull_projected_constraints(
-            m, constraints, [10, 8, 5, 6, 15, 19, 11, 3, 4, 1, 2]
+            m, constraints, [8, 6, 20, 21, 13, 17, 9, 1, 2, 3, 4]
         )
 
         # and check that we didn't change the model
diff --git a/pyomo/contrib/gdp_bounds/__init__.py b/pyomo/contrib/gdp_bounds/__init__.py
index 3a02f9e5f8e..ac71890cf7c 100644
--- a/pyomo/contrib/gdp_bounds/__init__.py
+++ b/pyomo/contrib/gdp_bounds/__init__.py
@@ -1 +1,12 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.contrib.gdp_bounds.plugins
diff --git a/pyomo/contrib/gdp_bounds/compute_bounds.py b/pyomo/contrib/gdp_bounds/compute_bounds.py
index f4f046e79df..3c04e4e1af7 100644
--- a/pyomo/contrib/gdp_bounds/compute_bounds.py
+++ b/pyomo/contrib/gdp_bounds/compute_bounds.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/gdp_bounds/info.py b/pyomo/contrib/gdp_bounds/info.py
index 3ee87041d25..e65df2bfab0 100644
--- a/pyomo/contrib/gdp_bounds/info.py
+++ b/pyomo/contrib/gdp_bounds/info.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """Provides functions for retrieving disjunctive variable bound information stored on a model."""
 
 from pyomo.common.collections import ComponentMap
@@ -24,10 +35,10 @@ def disjunctive_bound(var, scope):
     """Compute the disjunctive bounds for a variable in a given scope.
 
     Args:
-        var (_VarData): Variable for which to compute bound
+        var (VarData): Variable for which to compute bound
         scope (Component): The scope in which to compute the bound. If not a
-            _DisjunctData, it will walk up the tree and use the scope of the
-            most immediate enclosing _DisjunctData.
+            DisjunctData, it will walk up the tree and use the scope of the
+            most immediate enclosing DisjunctData.
 
     Returns:
         numeric: the tighter of either the disjunctive lower bound, the
diff --git a/pyomo/contrib/gdp_bounds/plugins.py b/pyomo/contrib/gdp_bounds/plugins.py
index 1ebe44378f0..016a1fc7b13 100644
--- a/pyomo/contrib/gdp_bounds/plugins.py
+++ b/pyomo/contrib/gdp_bounds/plugins.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/gdp_bounds/tests/__init__.py b/pyomo/contrib/gdp_bounds/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/gdp_bounds/tests/__init__.py
+++ b/pyomo/contrib/gdp_bounds/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/gdp_bounds/tests/test_gdp_bounds.py b/pyomo/contrib/gdp_bounds/tests/test_gdp_bounds.py
index e856ae247f3..0c8eae2c43b 100644
--- a/pyomo/contrib/gdp_bounds/tests/test_gdp_bounds.py
+++ b/pyomo/contrib/gdp_bounds/tests/test_gdp_bounds.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """Tests explicit bound to variable bound transformation module."""
 
 import pyomo.common.unittest as unittest
diff --git a/pyomo/contrib/gdpopt/GDPopt.py b/pyomo/contrib/gdpopt/GDPopt.py
index 3d45fa504cb..f0ff6d690d6 100644
--- a/pyomo/contrib/gdpopt/GDPopt.py
+++ b/pyomo/contrib/gdpopt/GDPopt.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/gdpopt/__init__.py b/pyomo/contrib/gdpopt/__init__.py
index 307fbc1594c..a84b8385ad3 100644
--- a/pyomo/contrib/gdpopt/__init__.py
+++ b/pyomo/contrib/gdpopt/__init__.py
@@ -1 +1,12 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 __version__ = (22, 5, 13)  # Note: date-based version number
diff --git a/pyomo/contrib/gdpopt/algorithm_base_class.py b/pyomo/contrib/gdpopt/algorithm_base_class.py
index 5bf41148700..c5929ad4a88 100644
--- a/pyomo/contrib/gdpopt/algorithm_base_class.py
+++ b/pyomo/contrib/gdpopt/algorithm_base_class.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/gdpopt/branch_and_bound.py b/pyomo/contrib/gdpopt/branch_and_bound.py
index 26dc2b5f2eb..36b81c881be 100644
--- a/pyomo/contrib/gdpopt/branch_and_bound.py
+++ b/pyomo/contrib/gdpopt/branch_and_bound.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -230,12 +230,12 @@ def _solve_gdp(self, model, config):
                 no_feasible_soln = float('inf')
                 self.LB = (
                     node_data.obj_lb
-                    if solve_data.objective_sense == minimize
+                    if self.objective_sense == minimize
                     else -no_feasible_soln
                 )
                 self.UB = (
                     no_feasible_soln
-                    if solve_data.objective_sense == minimize
+                    if self.objective_sense == minimize
                     else -node_data.obj_lb
                 )
                 config.logger.info(
diff --git a/pyomo/contrib/gdpopt/config_options.py b/pyomo/contrib/gdpopt/config_options.py
index 136baaa8e9c..186e6d7f6cc 100644
--- a/pyomo/contrib/gdpopt/config_options.py
+++ b/pyomo/contrib/gdpopt/config_options.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/gdpopt/create_oa_subproblems.py b/pyomo/contrib/gdpopt/create_oa_subproblems.py
index 12266866dbc..690fe1f15f1 100644
--- a/pyomo/contrib/gdpopt/create_oa_subproblems.py
+++ b/pyomo/contrib/gdpopt/create_oa_subproblems.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/gdpopt/cut_generation.py b/pyomo/contrib/gdpopt/cut_generation.py
index 36a826a4f83..742a2cde395 100644
--- a/pyomo/contrib/gdpopt/cut_generation.py
+++ b/pyomo/contrib/gdpopt/cut_generation.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/gdpopt/discrete_problem_initialize.py b/pyomo/contrib/gdpopt/discrete_problem_initialize.py
index 3dc18132c5b..81c339b94a2 100644
--- a/pyomo/contrib/gdpopt/discrete_problem_initialize.py
+++ b/pyomo/contrib/gdpopt/discrete_problem_initialize.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/gdpopt/enumerate.py b/pyomo/contrib/gdpopt/enumerate.py
index 45ecc8864f9..6c25d0088f4 100644
--- a/pyomo/contrib/gdpopt/enumerate.py
+++ b/pyomo/contrib/gdpopt/enumerate.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/gdpopt/gloa.py b/pyomo/contrib/gdpopt/gloa.py
index 68bd692f967..212da057e05 100644
--- a/pyomo/contrib/gdpopt/gloa.py
+++ b/pyomo/contrib/gdpopt/gloa.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/gdpopt/loa.py b/pyomo/contrib/gdpopt/loa.py
index 44c1f8609e8..354b61ae940 100644
--- a/pyomo/contrib/gdpopt/loa.py
+++ b/pyomo/contrib/gdpopt/loa.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/gdpopt/nlp_initialization.py b/pyomo/contrib/gdpopt/nlp_initialization.py
index fc083c095da..dbc33eb20be 100644
--- a/pyomo/contrib/gdpopt/nlp_initialization.py
+++ b/pyomo/contrib/gdpopt/nlp_initialization.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/gdpopt/oa_algorithm_utils.py b/pyomo/contrib/gdpopt/oa_algorithm_utils.py
index 9aba59e4527..ce4012d8800 100644
--- a/pyomo/contrib/gdpopt/oa_algorithm_utils.py
+++ b/pyomo/contrib/gdpopt/oa_algorithm_utils.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/gdpopt/plugins.py b/pyomo/contrib/gdpopt/plugins.py
index 3262dd65458..1f189c159f5 100644
--- a/pyomo/contrib/gdpopt/plugins.py
+++ b/pyomo/contrib/gdpopt/plugins.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/gdpopt/ric.py b/pyomo/contrib/gdpopt/ric.py
index 586a27362a1..2aa1aaf8c67 100644
--- a/pyomo/contrib/gdpopt/ric.py
+++ b/pyomo/contrib/gdpopt/ric.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/gdpopt/solve_discrete_problem.py b/pyomo/contrib/gdpopt/solve_discrete_problem.py
index 3de66fbaca0..54218edc50a 100644
--- a/pyomo/contrib/gdpopt/solve_discrete_problem.py
+++ b/pyomo/contrib/gdpopt/solve_discrete_problem.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/gdpopt/solve_subproblem.py b/pyomo/contrib/gdpopt/solve_subproblem.py
index bd9b85c0cef..e3980c3c784 100644
--- a/pyomo/contrib/gdpopt/solve_subproblem.py
+++ b/pyomo/contrib/gdpopt/solve_subproblem.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/gdpopt/tests/__init__.py b/pyomo/contrib/gdpopt/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/gdpopt/tests/__init__.py
+++ b/pyomo/contrib/gdpopt/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/gdpopt/tests/common_tests.py b/pyomo/contrib/gdpopt/tests/common_tests.py
index 5a363430381..88a2642704a 100644
--- a/pyomo/contrib/gdpopt/tests/common_tests.py
+++ b/pyomo/contrib/gdpopt/tests/common_tests.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/gdpopt/tests/test_LBB.py b/pyomo/contrib/gdpopt/tests/test_LBB.py
index 7d25767020e..8a553398fa6 100644
--- a/pyomo/contrib/gdpopt/tests/test_LBB.py
+++ b/pyomo/contrib/gdpopt/tests/test_LBB.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -59,6 +59,7 @@ def test_infeasible_GDP(self):
         self.assertIsNone(m.d.disjuncts[0].indicator_var.value)
         self.assertIsNone(m.d.disjuncts[1].indicator_var.value)
 
+    @unittest.skipUnless(z3_available, "Z3 SAT solver is not available")
     def test_infeasible_GDP_check_sat(self):
         """Test for infeasible GDP with check_sat option True."""
         m = ConcreteModel()
diff --git a/pyomo/contrib/gdpopt/tests/test_enumerate.py b/pyomo/contrib/gdpopt/tests/test_enumerate.py
index 606dd172064..8798557ddc9 100644
--- a/pyomo/contrib/gdpopt/tests/test_enumerate.py
+++ b/pyomo/contrib/gdpopt/tests/test_enumerate.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/gdpopt/tests/test_gdpopt.py b/pyomo/contrib/gdpopt/tests/test_gdpopt.py
index 1d5559a9b33..873bafabc76 100644
--- a/pyomo/contrib/gdpopt/tests/test_gdpopt.py
+++ b/pyomo/contrib/gdpopt/tests/test_gdpopt.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -22,7 +22,6 @@
 from pyomo.common.collections import Bunch
 from pyomo.common.config import ConfigDict, ConfigValue
 from pyomo.common.fileutils import import_file, PYOMO_ROOT_DIR
-from pyomo.contrib.appsi.solvers.gurobi import Gurobi
 from pyomo.contrib.gdpopt.create_oa_subproblems import (
     add_util_block,
     add_disjunct_list,
@@ -767,6 +766,9 @@ def test_time_limit(self):
             results.solver.termination_condition, TerminationCondition.maxTimeLimit
         )
 
+    @unittest.skipUnless(
+        license_available, "No BARON license--8PP logical problem exceeds demo size"
+    )
     def test_LOA_8PP_logical_default_init(self):
         """Test logic-based outer approximation with 8PP."""
         exfile = import_file(join(exdir, 'eight_process', 'eight_proc_logical.py'))
@@ -870,6 +872,9 @@ def test_LOA_8PP_maxBinary(self):
         )
         ct.check_8PP_solution(self, eight_process, results)
 
+    @unittest.skipUnless(
+        license_available, "No BARON license--8PP logical problem exceeds demo size"
+    )
     def test_LOA_8PP_logical_maxBinary(self):
         """Test logic-based OA with max_binary initialization."""
         exfile = import_file(join(exdir, 'eight_process', 'eight_proc_logical.py'))
@@ -1050,7 +1055,11 @@ def assert_correct_disjuncts_active(
 
         self.assertTrue(fabs(value(eight_process.profit.expr) - 68) <= 1e-2)
 
-    @unittest.skipUnless(Gurobi().available(), "APPSI Gurobi solver is not available")
+    @unittest.skipUnless(
+        SolverFactory('appsi_gurobi').available(exception_flag=False)
+        and SolverFactory('appsi_gurobi').license_is_valid(),
+        "Legacy APPSI Gurobi solver is not available",
+    )
     def test_auto_persistent_solver(self):
         exfile = import_file(join(exdir, 'eight_process', 'eight_proc_model.py'))
         m = exfile.build_eight_process_flowsheet()
@@ -1126,6 +1135,9 @@ def test_RIC_8PP_default_init(self):
         )
         ct.check_8PP_solution(self, eight_process, results)
 
+    @unittest.skipUnless(
+        license_available, "No BARON license--8PP logical problem exceeds demo size"
+    )
     def test_RIC_8PP_logical_default_init(self):
         """Test logic-based outer approximation with 8PP."""
         exfile = import_file(join(exdir, 'eight_process', 'eight_proc_logical.py'))
diff --git a/pyomo/contrib/gdpopt/util.py b/pyomo/contrib/gdpopt/util.py
index f288f9e2647..babe0245d57 100644
--- a/pyomo/contrib/gdpopt/util.py
+++ b/pyomo/contrib/gdpopt/util.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -553,6 +553,13 @@ def _add_bigm_constraint_to_transformed_model(m, constraint, block):
     # making a Reference to the ComponentData so that it will look like an
     # indexed component for now. If I redesign bigm at some point, then this
     # could be prettier.
-    bigm._transform_constraint(Reference(constraint), parent_disjunct, None, [], [])
+    bigm._transform_constraint(
+        Reference(constraint),
+        parent_disjunct,
+        None,
+        [],
+        [],
+        1 - parent_disjunct.binary_indicator_var,
+    )
     # Now get rid of it because this is a class attribute!
     del bigm._config
diff --git a/pyomo/contrib/gjh/GJH.py b/pyomo/contrib/gjh/GJH.py
index df9dfebf477..dc7c8de89c1 100644
--- a/pyomo/contrib/gjh/GJH.py
+++ b/pyomo/contrib/gjh/GJH.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/gjh/__init__.py b/pyomo/contrib/gjh/__init__.py
index d93cfd77b3c..a4a626013c4 100644
--- a/pyomo/contrib/gjh/__init__.py
+++ b/pyomo/contrib/gjh/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/gjh/getGJH.py b/pyomo/contrib/gjh/getGJH.py
index 112de054745..2d503c71438 100644
--- a/pyomo/contrib/gjh/getGJH.py
+++ b/pyomo/contrib/gjh/getGJH.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/gjh/plugins.py b/pyomo/contrib/gjh/plugins.py
index 4af2f38becd..f072f7b2c38 100644
--- a/pyomo/contrib/gjh/plugins.py
+++ b/pyomo/contrib/gjh/plugins.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/iis/__init__.py b/pyomo/contrib/iis/__init__.py
index eb9f60b8928..961ac576d42 100644
--- a/pyomo/contrib/iis/__init__.py
+++ b/pyomo/contrib/iis/__init__.py
@@ -1 +1,13 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.contrib.iis.iis import write_iis
+from pyomo.contrib.iis.mis import compute_infeasibility_explanation
diff --git a/pyomo/contrib/iis/iis.py b/pyomo/contrib/iis/iis.py
index bd192d04eb3..1ffd6cb0bd3 100644
--- a/pyomo/contrib/iis/iis.py
+++ b/pyomo/contrib/iis/iis.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """
 This module contains functions for computing an irreducible infeasible set
 for a Pyomo MILP or LP using a specified commercial solver, one of CPLEX,
diff --git a/pyomo/contrib/iis/mis.py b/pyomo/contrib/iis/mis.py
new file mode 100644
index 00000000000..6b6cca8e29c
--- /dev/null
+++ b/pyomo/contrib/iis/mis.py
@@ -0,0 +1,377 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+"""
+WaterTAP Copyright (c) 2020-2023, The Regents of the University of California, through Lawrence Berkeley National Laboratory, Oak Ridge National Laboratory, National Renewable Energy Laboratory, and National Energy Technology Laboratory (subject to receipt of any required approvals from the U.S. Dept. of Energy). All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
+
+    Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
+
+    Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
+
+    Neither the name of the University of California, Lawrence Berkeley National Laboratory, Oak Ridge National Laboratory, National Renewable Energy Laboratory, National Energy Technology Laboratory, U.S. Dept. of Energy nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+You are under no obligation whatsoever to provide any bug fixes, patches, or upgrades to the features, functionality or performance of the source code ("Enhancements") to anyone; however, if you choose to make your Enhancements available either publicly, or directly to Lawrence Berkeley National Laboratory, without imposing a separate written license agreement for such Enhancements, then you hereby grant the following license: a non-exclusive, royalty-free perpetual license to install, use, modify, prepare derivative works, incorporate into other computer software, distribute, and sublicense such enhancements or derivative works thereof, in binary and source code form.
+"""
+"""
+Minimal Intractable System (MIS) finder
+Originally written by Ben Knueven as part of the WaterTAP project:
+   https://github.com/watertap-org/watertap
+That's why this file has the watertap copyright notice.
+
+copied by DLW 18Feb2024 and edited
+
+See: https://www.sce.carleton.ca/faculty/chinneck/docs/CPAIOR07InfeasibilityTutorial.pdf
+"""
+
+import logging
+import pyomo.environ as pyo
+
+from pyomo.core.plugins.transform.add_slack_vars import AddSlackVariables
+
+from pyomo.core.plugins.transform.hierarchy import IsomorphicTransformation
+
+from pyomo.common.modeling import unique_component_name
+from pyomo.common.collections import ComponentMap, ComponentSet
+
+from pyomo.opt import WriterFactory
+
+logger = logging.getLogger("pyomo.contrib.iis")
+logger.setLevel(logging.INFO)
+
+
+class _VariableBoundsAsConstraints(IsomorphicTransformation):
+    """Replace all variables bounds and domain information with constraints.
+
+    Leaves fixed Vars untouched (for now)
+    """
+
+    def _apply_to(self, instance, **kwds):
+
+        bound_constr_block_name = unique_component_name(instance, "_variable_bounds")
+        instance.add_component(bound_constr_block_name, pyo.Block())
+        bound_constr_block = instance.component(bound_constr_block_name)
+
+        for v in instance.component_data_objects(pyo.Var, descend_into=True):
+            if v.fixed:
+                continue
+            lb, ub = v.bounds
+            if lb is None and ub is None:
+                continue
+            var_name = v.getname(fully_qualified=True)
+            if lb is not None:
+                con_name = "lb_for_" + var_name
+                con = pyo.Constraint(expr=(lb, v, None))
+                bound_constr_block.add_component(con_name, con)
+            if ub is not None:
+                con_name = "ub_for_" + var_name
+                con = pyo.Constraint(expr=(None, v, ub))
+                bound_constr_block.add_component(con_name, con)
+
+            # now we deactivate the variable bounds / domain
+            v.domain = pyo.Reals
+            v.setlb(None)
+            v.setub(None)
+
+
+def compute_infeasibility_explanation(
+    model, solver, tee=False, tolerance=1e-8, logger=logger
+):
+    """
+    This function attempts to determine why a given model is infeasible. It deploys
+    two main algorithms:
+
+    1. Successfully relaxes the constraints of the problem, and reports to the user
+       some sets of constraints and variable bounds, which when relaxed, creates a
+       feasible model.
+    2. Uses the information collected from (1) to attempt to compute a Minimal
+       Infeasible System (MIS), which is a set of constraints and variable bounds
+       which appear to be in conflict with each other. It is minimal in the sense
+       that removing any single constraint or variable bound would result in a
+       feasible subsystem.
+
+    Args
+    ----
+        model: A pyomo block
+        solver: A pyomo solver object or a string for SolverFactory
+        tee (optional):  Display intermediate solves conducted (False)
+        tolerance (optional): The feasibility tolerance to use when declaring a
+            constraint feasible (1e-08)
+        logger:logging.Logger
+            A logger for messages. Uses pyomo.contrib.mis logger by default.
+
+    """
+    # Suggested enhancement: It might be useful to return sets of names for each set of relaxed components, as well as the final minimal infeasible system
+
+    # hold the original harmless
+    modified_model = model.clone()
+
+    if solver is None:
+        raise ValueError("A solver must be supplied")
+    elif isinstance(solver, str):
+        solver = pyo.SolverFactory(solver)
+    else:
+        # assume we have a solver
+        assert solver.available()
+
+    # first, cache the values we get
+    _value_cache = ComponentMap()
+    for v in model.component_data_objects(pyo.Var, descend_into=True):
+        _value_cache[v] = v.value
+
+    # finding proper reference
+    if model.parent_block() is None:
+        common_name = ""
+    else:
+        common_name = model.name + "."
+
+    _modified_model_var_to_original_model_var = ComponentMap()
+    _modified_model_value_cache = ComponentMap()
+
+    for v in model.component_data_objects(pyo.Var, descend_into=True):
+        modified_model_var = modified_model.find_component(v.name[len(common_name) :])
+
+        _modified_model_var_to_original_model_var[modified_model_var] = v
+        _modified_model_value_cache[modified_model_var] = _value_cache[v]
+        modified_model_var.set_value(_value_cache[v], skip_validation=True)
+
+    # TODO: For WT / IDAES models, we should probably be more
+    #       selective in *what* we elasticize. E.g., it probably
+    #       does not make sense to elasticize property calculations
+    #       and maybe certain other equality constraints calculating
+    #       values. Maybe we shouldn't elasticize *any* equality
+    #       constraints.
+    #       For example, elasticizing the calculation of mass fraction
+    #       makes absolutely no sense and will just be noise for the
+    #       modeler to sift through. We could try to sort the constraints
+    #       such that we look for those with linear coefficients `1` on
+    #       some term and leave those be.
+    #       Alternatively, we could apply this tool to a version of the
+    #       model that has as many as possible of these constraints
+    #       "substituted out".
+    # move the variable bounds to the constraints
+    _VariableBoundsAsConstraints().apply_to(modified_model)
+
+    AddSlackVariables().apply_to(modified_model)
+    slack_block = modified_model._core_add_slack_variables
+
+    for v in slack_block.component_data_objects(pyo.Var):
+        v.fix(0)
+    # start with variable bounds -- these are the easiest to interpret
+    for c in modified_model._variable_bounds.component_data_objects(
+        pyo.Constraint, descend_into=True
+    ):
+        plus = slack_block.component(f"_slack_plus_{c.name}")
+        minus = slack_block.component(f"_slack_minus_{c.name}")
+        assert not (plus is None and minus is None)
+        if plus is not None:
+            plus.unfix()
+        if minus is not None:
+            minus.unfix()
+
+    # TODO: Elasticizing too much at once seems to cause Ipopt trouble.
+    #       After an initial sweep, we should just fix one elastic variable
+    #       and put everything else on a stack of "constraints to elasticize".
+    #       We elasticize one constraint at a time and fix one constraint at a time.
+    #       After fixing an elastic variable, we elasticize a single constraint it
+    #       appears in and put the remaining constraints on the stack. If the resulting problem
+    #       is feasible, we keep going "down the tree". If the resulting problem is
+    #       infeasible or cannot be solved, we elasticize a single constraint from
+    #       the top of the stack.
+    #       The algorithm stops when the stack is empty and the subproblem is infeasible.
+    #       Along the way, any time the current problem is infeasible we can check to
+    #       see if the current set of constraints in the filter is as a collection of
+    #       infeasible constraints -- to terminate early.
+    #       However, while more stable, this is much more computationally intensive.
+    #       So, we leave the implementation simpler for now and consider this as
+    #       a potential extension if this tool sometimes cannot report a good answer.
+    # Phase 1 -- build the initial set of constraints, or prove feasibility
+    msg = ""
+    fixed_slacks = ComponentSet()
+    elastic_filter = ComponentSet()
+
+    def _constraint_loop(relaxed_things, msg):
+        if msg == "":
+            msg += f"Model {model.name} may be infeasible. A feasible solution was found with only the following {relaxed_things} relaxed:\n"
+        else:
+            msg += f"Another feasible solution was found with only the following {relaxed_things} relaxed:\n"
+        while True:
+
+            def _constraint_generator():
+                elastic_filter_size_initial = len(elastic_filter)
+                for v in slack_block.component_data_objects(pyo.Var):
+                    if v.value > tolerance:
+                        constr = _get_constraint(modified_model, v)
+                        yield constr, v.value
+                        v.fix(0)
+                        fixed_slacks.add(v)
+                        elastic_filter.add(constr)
+                if len(elastic_filter) == elastic_filter_size_initial:
+                    raise Exception(f"Found model {model.name} to be feasible!")
+
+            msg = _get_results_with_value(_constraint_generator(), msg)
+            for var, val in _modified_model_value_cache.items():
+                var.set_value(val, skip_validation=True)
+            results = solver.solve(modified_model, tee=tee)
+            if pyo.check_optimal_termination(results):
+                msg += f"Another feasible solution was found with only the following {relaxed_things} relaxed:\n"
+            else:
+                break
+        return msg
+
+    results = solver.solve(modified_model, tee=tee)
+    if pyo.check_optimal_termination(results):
+        msg = _constraint_loop("variable bounds", msg)
+
+    # next, try relaxing the inequality constraints
+    for v in slack_block.component_data_objects(pyo.Var):
+        c = _get_constraint(modified_model, v)
+        if c.equality:
+            # equality constraint
+            continue
+        if v not in fixed_slacks:
+            v.unfix()
+
+    results = solver.solve(modified_model, tee=tee)
+    if pyo.check_optimal_termination(results):
+        msg = _constraint_loop("inequality constraints and/or variable bounds", msg)
+
+    for v in slack_block.component_data_objects(pyo.Var):
+        if v not in fixed_slacks:
+            v.unfix()
+
+    results = solver.solve(modified_model, tee=tee)
+    if pyo.check_optimal_termination(results):
+        msg = _constraint_loop(
+            "inequality constraints, equality constraints, and/or variable bounds", msg
+        )
+
+    if len(elastic_filter) == 0:
+        # load the feasible solution into the original model
+        for modified_model_var, v in _modified_model_var_to_original_model_var.items():
+            v.set_value(modified_model_var.value, skip_validation=True)
+        results = solver.solve(model, tee=tee)
+        if pyo.check_optimal_termination(results):
+            logger.info(f"A feasible solution was found!")
+        else:
+            logger.info(
+                f"Could not find a feasible solution with violated constraints or bounds. This model is likely unstable"
+            )
+
+    # Phase 2 -- deletion filter
+    # remove slacks by fixing them to 0
+    for v in slack_block.component_data_objects(pyo.Var):
+        v.fix(0)
+    for o in modified_model.component_data_objects(pyo.Objective, descend_into=True):
+        o.deactivate()
+
+    # mark all constraints not in the filter as inactive
+    for c in modified_model.component_data_objects(pyo.Constraint):
+        if c in elastic_filter:
+            continue
+        else:
+            c.deactivate()
+
+    try:
+        results = solver.solve(modified_model, tee=tee)
+    except:
+        results = None
+
+    if pyo.check_optimal_termination(results):
+        msg += "Could not determine Minimal Intractable System\n"
+    else:
+        deletion_filter = []
+        guards = []
+        for constr in elastic_filter:
+            constr.deactivate()
+            for var, val in _modified_model_value_cache.items():
+                var.set_value(val, skip_validation=True)
+            math_failure = False
+            try:
+                results = solver.solve(modified_model, tee=tee)
+            except:
+                math_failure = True
+
+            if math_failure:
+                constr.activate()
+                guards.append(constr)
+            elif pyo.check_optimal_termination(results):
+                constr.activate()
+                deletion_filter.append(constr)
+            else:  # still infeasible without this constraint
+                pass
+
+        msg += "Computed Minimal Intractable System (MIS)!\n"
+        msg += "Constraints / bounds in MIS:\n"
+        msg = _get_results(deletion_filter, msg)
+        msg += "Constraints / bounds in guards for stability:"
+        msg = _get_results(guards, msg)
+
+    logger.info(msg)
+
+
+def _get_results_with_value(constr_value_generator, msg=None):
+    # note that "lb_for_" and "ub_for_" are 7 characters long
+    if msg is None:
+        msg = ""
+    for c, value in constr_value_generator:
+        c_name = c.name
+        if "_variable_bounds" in c_name:
+            name = c.local_name
+            if "lb" in name:
+                msg += f"\tlb of var {name[7:]} by {value}\n"
+            elif "ub" in name:
+                msg += f"\tub of var {name[7:]} by {value}\n"
+            else:
+                raise RuntimeError("unrecognized var name")
+        else:
+            msg += f"\tconstraint: {c_name} by {value}\n"
+    return msg
+
+
+def _get_results(constr_generator, msg=None):
+    # note that "lb_for_" and "ub_for_" are 7 characters long
+    if msg is None:
+        msg = ""
+    for c in constr_generator:
+        c_name = c.name
+        if "_variable_bounds" in c_name:
+            name = c.local_name
+            if "lb" in name:
+                msg += f"\tlb of var {name[7:]}\n"
+            elif "ub" in name:
+                msg += f"\tub of var {name[7:]}\n"
+            else:
+                raise RuntimeError("unrecognized var name")
+        else:
+            msg += f"\tconstraint: {c_name}\n"
+    return msg
+
+
+def _get_constraint(modified_model, v):
+    if "_slack_plus_" in v.name:
+        constr = modified_model.find_component(v.local_name[len("_slack_plus_") :])
+        if constr is None:
+            raise RuntimeError(
+                f"Bad constraint name {v.local_name[len('_slack_plus_'):]}"
+            )
+        return constr
+    elif "_slack_minus_" in v.name:
+        constr = modified_model.find_component(v.local_name[len("_slack_minus_") :])
+        if constr is None:
+            raise RuntimeError(
+                f"Bad constraint name {v.local_name[len('_slack_minus_'):]}"
+            )
+        return constr
+    else:
+        raise RuntimeError(f"Bad var name {v.name}")
diff --git a/pyomo/contrib/iis/tests/__init__.py b/pyomo/contrib/iis/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/iis/tests/__init__.py
+++ b/pyomo/contrib/iis/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/iis/tests/test_iis.py b/pyomo/contrib/iis/tests/test_iis.py
index b1b675d5081..cf7b5613a3a 100644
--- a/pyomo/contrib/iis/tests/test_iis.py
+++ b/pyomo/contrib/iis/tests/test_iis.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.common.unittest as unittest
 import pyomo.environ as pyo
 from pyomo.contrib.iis import write_iis
diff --git a/pyomo/contrib/iis/tests/test_mis.py b/pyomo/contrib/iis/tests/test_mis.py
new file mode 100644
index 00000000000..bbdb2367016
--- /dev/null
+++ b/pyomo/contrib/iis/tests/test_mis.py
@@ -0,0 +1,125 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import pyomo.common.unittest as unittest
+import pyomo.environ as pyo
+import pyomo.contrib.iis.mis as mis
+from pyomo.contrib.iis.mis import _get_constraint
+from pyomo.common.tempfiles import TempfileManager
+
+import logging
+import os
+
+
+def _get_infeasible_model():
+    m = pyo.ConcreteModel("trivial4test")
+    m.x = pyo.Var(within=pyo.Binary)
+    m.y = pyo.Var(within=pyo.NonNegativeReals)
+
+    m.c1 = pyo.Constraint(expr=m.y <= 100.0 * m.x)
+    m.c2 = pyo.Constraint(expr=m.y <= -100.0 * m.x)
+    m.c3 = pyo.Constraint(expr=m.x >= 0.5)
+
+    m.o = pyo.Objective(expr=-m.y)
+
+    return m
+
+
+def _get_feasible_model():
+    m = pyo.ConcreteModel("Trivial Feasible Quad")
+    m.x = pyo.Var([1, 2], bounds=(0, 1))
+    m.y = pyo.Var(bounds=(0, 1))
+    m.c = pyo.Constraint(expr=m.x[1] * m.x[2] >= -1)
+    m.d = pyo.Constraint(expr=m.x[1] + m.y >= 1)
+
+    return m
+
+
+class TestMIS(unittest.TestCase):
+    @unittest.skipUnless(
+        pyo.SolverFactory("ipopt").available(exception_flag=False),
+        "ipopt not available",
+    )
+    def test_write_mis_ipopt(self):
+        _test_mis("ipopt")
+
+    def test__get_constraint_errors(self):
+        # A not-completely-cynical way to get the coverage up.
+        m = _get_infeasible_model()  # not modified
+        fct = _get_constraint
+
+        m.foo_slack_plus_ = pyo.Var()
+        self.assertRaises(RuntimeError, fct, m, m.foo_slack_plus_)
+        m.foo_slack_minus_ = pyo.Var()
+        self.assertRaises(RuntimeError, fct, m, m.foo_slack_minus_)
+        m.foo_bar = pyo.Var()
+        self.assertRaises(RuntimeError, fct, m, m.foo_bar)
+
+    def test_feasible_model(self):
+        m = _get_feasible_model()
+        opt = pyo.SolverFactory("ipopt")
+        self.assertRaises(Exception, mis.compute_infeasibility_explanation, m, opt)
+
+
+def _check_output(file_name):
+    # pretty simple check for now
+    with open(file_name, "r+") as file1:
+        lines = file1.readlines()
+    trigger = "Constraints / bounds in MIS:"
+    nugget = "lb of var y"
+    live = False  # (long i)
+    found_nugget = False
+    for line in lines:
+        if trigger in line:
+            live = True
+        if live:
+            if nugget in line:
+                found_nugget = True
+    if not found_nugget:
+        raise RuntimeError(f"Did not find '{nugget}' after '{trigger}' in output")
+    else:
+        pass
+
+
+def _test_mis(solver_name):
+    m = _get_infeasible_model()
+    opt = pyo.SolverFactory(solver_name)
+
+    # This test seems to fail on Windows as it unlinks the tempfile, so live with it
+    #    On a Windows machine, we will not use a temp dir and just try to delete the log file
+    if os.name == "nt":
+        file_name = f"_test_mis_{solver_name}.log"
+        logger = logging.getLogger(f"test_mis_{solver_name}")
+        logger.setLevel(logging.INFO)
+        fh = logging.FileHandler(file_name)
+        fh.setLevel(logging.DEBUG)
+        logger.addHandler(fh)
+
+        mis.compute_infeasibility_explanation(m, opt, logger=logger)
+        _check_output(file_name)
+        # os.remove(file_name) cannot remove it on Windows. Still in use.
+
+    else:  # not windows
+        with TempfileManager.new_context() as tmpmgr:
+            tmp_path = tmpmgr.mkdtemp()
+            file_name = os.path.join(tmp_path, f"_test_mis_{solver_name}.log")
+            logger = logging.getLogger(f"test_mis_{solver_name}")
+            logger.setLevel(logging.INFO)
+            fh = logging.FileHandler(file_name)
+            fh.setLevel(logging.DEBUG)
+            logger.addHandler(fh)
+
+            mis.compute_infeasibility_explanation(m, opt, logger=logger)
+            _check_output(file_name)
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/pyomo/contrib/iis/tests/trivial_mis.py b/pyomo/contrib/iis/tests/trivial_mis.py
new file mode 100644
index 00000000000..4cf0dd7a357
--- /dev/null
+++ b/pyomo/contrib/iis/tests/trivial_mis.py
@@ -0,0 +1,24 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+import pyomo.environ as pyo
+
+m = pyo.ConcreteModel("Trivial Quad")
+m.x = pyo.Var([1, 2], bounds=(0, 1))
+m.y = pyo.Var(bounds=(0, 1))
+m.c = pyo.Constraint(expr=m.x[1] * m.x[2] == -1)
+m.d = pyo.Constraint(expr=m.x[1] + m.y >= 1)
+
+from pyomo.contrib.iis.mis import compute_infeasibility_explanation
+
+# Note: this particular little problem is quadratic
+# As of 18Feb2024 DLW is not sure the explanation code works with solvers other than ipopt
+ipopt = pyo.SolverFactory("ipopt")
+compute_infeasibility_explanation(m, solver=ipopt)
diff --git a/pyomo/contrib/incidence_analysis/__init__.py b/pyomo/contrib/incidence_analysis/__init__.py
index ee078690f2f..8942d09b6b9 100644
--- a/pyomo/contrib/incidence_analysis/__init__.py
+++ b/pyomo/contrib/incidence_analysis/__init__.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from .triangularize import block_triangularize
 from .matching import maximum_matching
 from .interface import IncidenceGraphInterface, get_bipartite_incidence_graph
diff --git a/pyomo/contrib/incidence_analysis/common/__init__.py b/pyomo/contrib/incidence_analysis/common/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/incidence_analysis/common/__init__.py
+++ b/pyomo/contrib/incidence_analysis/common/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/incidence_analysis/common/dulmage_mendelsohn.py b/pyomo/contrib/incidence_analysis/common/dulmage_mendelsohn.py
index 09a926cdec2..5bc724fafc1 100644
--- a/pyomo/contrib/incidence_analysis/common/dulmage_mendelsohn.py
+++ b/pyomo/contrib/incidence_analysis/common/dulmage_mendelsohn.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/incidence_analysis/common/tests/__init__.py b/pyomo/contrib/incidence_analysis/common/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/incidence_analysis/common/tests/__init__.py
+++ b/pyomo/contrib/incidence_analysis/common/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/incidence_analysis/common/tests/test_dulmage_mendelsohn.py b/pyomo/contrib/incidence_analysis/common/tests/test_dulmage_mendelsohn.py
index 1675fc7420a..b17ae9b1dfc 100644
--- a/pyomo/contrib/incidence_analysis/common/tests/test_dulmage_mendelsohn.py
+++ b/pyomo/contrib/incidence_analysis/common/tests/test_dulmage_mendelsohn.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/incidence_analysis/config.py b/pyomo/contrib/incidence_analysis/config.py
index a107792a9cd..9fac48c8a26 100644
--- a/pyomo/contrib/incidence_analysis/config.py
+++ b/pyomo/contrib/incidence_analysis/config.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -13,6 +13,9 @@
 
 import enum
 from pyomo.common.config import ConfigDict, ConfigValue, InEnum
+from pyomo.common.modeling import NOTSET
+from pyomo.repn.plugins.nl_writer import AMPLRepnVisitor, text_nl_template
+from pyomo.repn.util import FileDeterminism, FileDeterminism_to_SortComponents
 
 
 class IncidenceMethod(enum.Enum):
@@ -24,6 +27,21 @@ class IncidenceMethod(enum.Enum):
     standard_repn = 1
     """Use ``pyomo.repn.standard_repn.generate_standard_repn``"""
 
+    standard_repn_compute_values = 2
+    """Use ``pyomo.repn.standard_repn.generate_standard_repn`` with
+    ``compute_values=True``
+    """
+
+    ampl_repn = 3
+    """Use ``pyomo.repn.plugins.nl_writer.AMPLRepnVisitor``"""
+
+
+class IncidenceOrder(enum.Enum):
+
+    dulmage_mendelsohn_upper = 0
+
+    dulmage_mendelsohn_lower = 1
+
 
 _include_fixed = ConfigValue(
     default=False,
@@ -54,6 +72,21 @@ class IncidenceMethod(enum.Enum):
 )
 
 
+def _amplrepnvisitor_validator(visitor):
+    if not isinstance(visitor, AMPLRepnVisitor):
+        raise TypeError(
+            "'visitor' config argument should be an instance of AMPLRepnVisitor"
+        )
+    return visitor
+
+
+_ampl_repn_visitor = ConfigValue(
+    default=None,
+    domain=_amplrepnvisitor_validator,
+    description="Visitor used to generate AMPLRepn of each constraint",
+)
+
+
 IncidenceConfig = ConfigDict()
 """Options for incidence graph generation
 
@@ -63,6 +96,9 @@ class IncidenceMethod(enum.Enum):
   should be included.
 - ``method`` -- Method used to identify incident variables. Must be a value of the
   ``IncidenceMethod`` enum.
+- ``_ampl_repn_visitor`` -- Expression visitor used to generate ``AMPLRepn`` of each
+  constraint. Must be an instance of ``AMPLRepnVisitor``. *This option is constructed
+  automatically when needed and should not be set by users!*
 
 """
 
@@ -74,3 +110,44 @@ class IncidenceMethod(enum.Enum):
 
 
 IncidenceConfig.declare("method", _method)
+
+
+IncidenceConfig.declare("_ampl_repn_visitor", _ampl_repn_visitor)
+
+
+def get_config_from_kwds(**kwds):
+    """Get an instance of IncidenceConfig from provided keyword arguments.
+
+    If the ``method`` argument is ``IncidenceMethod.ampl_repn`` and no
+    ``AMPLRepnVisitor`` has been provided, a new ``AMPLRepnVisitor`` is
+    constructed. This function should generally be used by callers such
+    as ``IncidenceGraphInterface`` to ensure that a visitor is created then
+    re-used when calling ``get_incident_variables`` in a loop.
+
+    """
+    if (
+        kwds.get("method", None) is IncidenceMethod.ampl_repn
+        and kwds.get("_ampl_repn_visitor", None) is None
+    ):
+        subexpression_cache = {}
+        external_functions = {}
+        var_map = {}
+        used_named_expressions = set()
+        symbolic_solver_labels = False
+        # TODO: Explore potential performance benefit of exporting defined variables.
+        # This likely only shows up if we can preserve the subexpression cache across
+        # multiple constraint expressions.
+        export_defined_variables = False
+        sorter = FileDeterminism_to_SortComponents(FileDeterminism.ORDERED)
+        amplvisitor = AMPLRepnVisitor(
+            text_nl_template,
+            subexpression_cache,
+            external_functions,
+            var_map,
+            used_named_expressions,
+            symbolic_solver_labels,
+            export_defined_variables,
+            sorter,
+        )
+        kwds["_ampl_repn_visitor"] = amplvisitor
+    return IncidenceConfig(kwds)
diff --git a/pyomo/contrib/incidence_analysis/connected.py b/pyomo/contrib/incidence_analysis/connected.py
index 2dcf31c0fe0..28d4bdee73f 100644
--- a/pyomo/contrib/incidence_analysis/connected.py
+++ b/pyomo/contrib/incidence_analysis/connected.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/incidence_analysis/dulmage_mendelsohn.py b/pyomo/contrib/incidence_analysis/dulmage_mendelsohn.py
index eb24b0559fc..3a6d06a809c 100644
--- a/pyomo/contrib/incidence_analysis/dulmage_mendelsohn.py
+++ b/pyomo/contrib/incidence_analysis/dulmage_mendelsohn.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/incidence_analysis/incidence.py b/pyomo/contrib/incidence_analysis/incidence.py
index 1852cf75648..030ee2b0f79 100644
--- a/pyomo/contrib/incidence_analysis/incidence.py
+++ b/pyomo/contrib/incidence_analysis/incidence.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -17,7 +17,11 @@
 from pyomo.core.expr.numvalue import value as pyo_value
 from pyomo.repn import generate_standard_repn
 from pyomo.util.subsystems import TemporarySubsystemManager
-from pyomo.contrib.incidence_analysis.config import IncidenceMethod, IncidenceConfig
+from pyomo.repn.plugins.nl_writer import AMPLRepn
+from pyomo.contrib.incidence_analysis.config import (
+    IncidenceMethod,
+    get_config_from_kwds,
+)
 
 
 #
@@ -29,7 +33,9 @@ def _get_incident_via_identify_variables(expr, include_fixed):
     return list(identify_variables(expr, include_fixed=include_fixed))
 
 
-def _get_incident_via_standard_repn(expr, include_fixed, linear_only):
+def _get_incident_via_standard_repn(
+    expr, include_fixed, linear_only, compute_values=False
+):
     if include_fixed:
         to_unfix = [
             var for var in identify_variables(expr, include_fixed=True) if var.fixed
@@ -39,7 +45,9 @@ def _get_incident_via_standard_repn(expr, include_fixed, linear_only):
         context = nullcontext()
 
     with context:
-        repn = generate_standard_repn(expr, compute_values=False, quadratic=False)
+        repn = generate_standard_repn(
+            expr, compute_values=compute_values, quadratic=False
+        )
 
     linear_vars = []
     # Check coefficients to make sure we don't include linear variables with
@@ -74,6 +82,47 @@ def _get_incident_via_standard_repn(expr, include_fixed, linear_only):
         return unique_variables
 
 
+def _get_incident_via_ampl_repn(expr, linear_only, visitor):
+    def _nonlinear_var_id_collector(idlist):
+        for _id in idlist:
+            if _id in visitor.subexpression_cache:
+                info = visitor.subexpression_cache[_id][1]
+                if info.nonlinear:
+                    yield from _nonlinear_var_id_collector(info.nonlinear[1])
+                if info.linear:
+                    yield from _nonlinear_var_id_collector(info.linear)
+            else:
+                yield _id
+
+    var_map = visitor.var_map
+    orig_activevisitor = AMPLRepn.ActiveVisitor
+    AMPLRepn.ActiveVisitor = visitor
+    try:
+        repn = visitor.walk_expression((expr, None, 0, 1.0))
+    finally:
+        AMPLRepn.ActiveVisitor = orig_activevisitor
+
+    nonlinear_var_id_set = set()
+    unique_nonlinear_var_ids = []
+    if repn.nonlinear:
+        for v_id in _nonlinear_var_id_collector(repn.nonlinear[1]):
+            if v_id not in nonlinear_var_id_set:
+                nonlinear_var_id_set.add(v_id)
+                unique_nonlinear_var_ids.append(v_id)
+
+    nonlinear_vars = [var_map[v_id] for v_id in unique_nonlinear_var_ids]
+    linear_only_vars = [
+        var_map[v_id]
+        for v_id, coef in repn.linear.items()
+        if coef != 0.0 and v_id not in nonlinear_var_id_set
+    ]
+    if linear_only:
+        return linear_only_vars
+    else:
+        variables = linear_only_vars + nonlinear_vars
+        return variables
+
+
 def get_incident_variables(expr, **kwds):
     """Get variables that participate in an expression
 
@@ -112,21 +161,38 @@ def get_incident_variables(expr, **kwds):
        ['x[1]', 'x[2]']
 
     """
-    config = IncidenceConfig(kwds)
+    config = get_config_from_kwds(**kwds)
     method = config.method
     include_fixed = config.include_fixed
     linear_only = config.linear_only
+    amplrepnvisitor = config._ampl_repn_visitor
+
+    # Check compatibility of arguments
     if linear_only and method is IncidenceMethod.identify_variables:
         raise RuntimeError(
             "linear_only=True is not supported when using identify_variables"
         )
+    if include_fixed and method is IncidenceMethod.ampl_repn:
+        raise RuntimeError("include_fixed=True is not supported when using ampl_repn")
+    if method is IncidenceMethod.ampl_repn and amplrepnvisitor is None:
+        # Developer error, this should never happen!
+        raise RuntimeError("_ampl_repn_visitor must be provided when using ampl_repn")
+
+    # Dispatch to correct method
     if method is IncidenceMethod.identify_variables:
         return _get_incident_via_identify_variables(expr, include_fixed)
     elif method is IncidenceMethod.standard_repn:
-        return _get_incident_via_standard_repn(expr, include_fixed, linear_only)
+        return _get_incident_via_standard_repn(
+            expr, include_fixed, linear_only, compute_values=False
+        )
+    elif method is IncidenceMethod.standard_repn_compute_values:
+        return _get_incident_via_standard_repn(
+            expr, include_fixed, linear_only, compute_values=True
+        )
+    elif method is IncidenceMethod.ampl_repn:
+        return _get_incident_via_ampl_repn(expr, linear_only, amplrepnvisitor)
     else:
         raise ValueError(
             f"Unrecognized value {method} for the method used to identify incident"
-            f" variables. Valid options are {IncidenceMethod.identify_variables}"
-            f" and {IncidenceMethod.standard_repn}."
+            f" variables. See the IncidenceMethod enum for valid methods."
         )
diff --git a/pyomo/contrib/incidence_analysis/interface.py b/pyomo/contrib/incidence_analysis/interface.py
index e922551c6a4..73d9722eb7e 100644
--- a/pyomo/contrib/incidence_analysis/interface.py
+++ b/pyomo/contrib/incidence_analysis/interface.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -15,7 +15,7 @@
 
 import enum
 import textwrap
-from pyomo.core.base.block import _BlockData
+from pyomo.core.base.block import BlockData
 from pyomo.core.base.var import Var
 from pyomo.core.base.constraint import Constraint
 from pyomo.core.base.objective import Objective
@@ -28,8 +28,8 @@
     scipy as sp,
     plotly,
 )
-from pyomo.common.deprecation import deprecated
-from pyomo.contrib.incidence_analysis.config import IncidenceConfig
+from pyomo.common.deprecation import deprecated, deprecation_warning
+from pyomo.contrib.incidence_analysis.config import get_config_from_kwds
 from pyomo.contrib.incidence_analysis.matching import maximum_matching
 from pyomo.contrib.incidence_analysis.connected import get_independent_submatrices
 from pyomo.contrib.incidence_analysis.triangularize import (
@@ -47,7 +47,7 @@
 from pyomo.contrib.pynumero.asl import AmplInterface
 
 pyomo_nlp, pyomo_nlp_available = attempt_import(
-    'pyomo.contrib.pynumero.interfaces.pyomo_nlp'
+    "pyomo.contrib.pynumero.interfaces.pyomo_nlp"
 )
 asl_available = pyomo_nlp_available & AmplInterface.available()
 
@@ -62,7 +62,7 @@ def _check_unindexed(complist):
 
 
 def get_incidence_graph(variables, constraints, **kwds):
-    config = IncidenceConfig(kwds)
+    config = get_config_from_kwds(**kwds)
     return get_bipartite_incidence_graph(variables, constraints, **config)
 
 
@@ -91,7 +91,9 @@ def get_bipartite_incidence_graph(variables, constraints, **kwds):
     ``networkx.Graph``
 
     """
-    config = IncidenceConfig(kwds)
+    # Note that this ConfigDict contains the visitor that we will re-use
+    # when constructing constraints.
+    config = get_config_from_kwds(**kwds)
     _check_unindexed(variables + constraints)
     N = len(variables)
     M = len(constraints)
@@ -134,36 +136,34 @@ def extract_bipartite_subgraph(graph, nodes0, nodes1):
         in the original graph.
 
     """
-    subgraph = nx.Graph()
-    sub_M = len(nodes0)
-    sub_N = len(nodes1)
-    subgraph.add_nodes_from(range(sub_M), bipartite=0)
-    subgraph.add_nodes_from(range(sub_M, sub_M + sub_N), bipartite=1)
-
+    subgraph = graph.subgraph(nodes0 + nodes1)
+    # TODO: Any error checking that nodes are valid bipartition?
+    for node in nodes0:
+        bipartite = graph.nodes[node]["bipartite"]
+        if bipartite != 0:
+            raise RuntimeError(
+                "Invalid bipartite sets. Node {node} in set 0 has"
+                " bipartite={bipartite}"
+            )
+    for node in nodes1:
+        bipartite = graph.nodes[node]["bipartite"]
+        if bipartite != 1:
+            raise RuntimeError(
+                "Invalid bipartite sets. Node {node} in set 1 has"
+                " bipartite={bipartite}"
+            )
     old_new_map = {}
     for i, node in enumerate(nodes0 + nodes1):
         if node in old_new_map:
             raise RuntimeError("Node %s provided more than once.")
         old_new_map[node] = i
-
-    for node1, node2 in graph.edges():
-        if node1 in old_new_map and node2 in old_new_map:
-            new_node_1 = old_new_map[node1]
-            new_node_2 = old_new_map[node2]
-            if (
-                subgraph.nodes[new_node_1]["bipartite"]
-                == subgraph.nodes[new_node_2]["bipartite"]
-            ):
-                raise RuntimeError(
-                    "Subgraph is not bipartite. Found an edge between nodes"
-                    " %s and %s (in the original graph)." % (node1, node2)
-                )
-            subgraph.add_edge(new_node_1, new_node_2)
-    return subgraph
+    relabeled_subgraph = nx.relabel_nodes(subgraph, old_new_map)
+    return relabeled_subgraph
 
 
 def _generate_variables_in_constraints(constraints, **kwds):
-    config = IncidenceConfig(kwds)
+    # Note: We construct a visitor here
+    config = get_config_from_kwds(**kwds)
     known_vars = ComponentSet()
     for con in constraints:
         for var in get_incident_variables(con.body, **config):
@@ -191,7 +191,7 @@ def get_structural_incidence_matrix(variables, constraints, **kwds):
         Entries are 1.0.
 
     """
-    config = IncidenceConfig(kwds)
+    config = get_config_from_kwds(**kwds)
     _check_unindexed(variables + constraints)
     N, M = len(variables), len(constraints)
     var_idx_map = ComponentMap((v, i) for i, v in enumerate(variables))
@@ -266,7 +266,6 @@ class IncidenceGraphInterface(object):
         ``evaluate_jacobian_eq`` method instead of ``evaluate_jacobian``
         rather than checking constraint expression types.
 
-
     """
 
     def __init__(self, model=None, active=True, include_inequality=True, **kwds):
@@ -275,12 +274,12 @@ def __init__(self, model=None, active=True, include_inequality=True, **kwds):
         # to cache the incidence graph for fast analysis later on.
         # WARNING: This cache will become invalid if the user alters their
         # model.
-        self._config = IncidenceConfig(kwds)
+        self._config = get_config_from_kwds(**kwds)
         if model is None:
             self._incidence_graph = None
             self._variables = None
             self._constraints = None
-        elif isinstance(model, _BlockData):
+        elif isinstance(model, BlockData):
             self._constraints = [
                 con
                 for con in model.component_data_objects(Constraint, active=active)
@@ -330,10 +329,26 @@ def __init__(self, model=None, active=True, include_inequality=True, **kwds):
                 incidence_matrix = nlp.evaluate_jacobian_eq()
             nxb = nx.algorithms.bipartite
             self._incidence_graph = nxb.from_biadjacency_matrix(incidence_matrix)
+        elif isinstance(model, tuple):
+            # model is a tuple of (nx.Graph, list[pyo.Var], list[pyo.Constraint])
+            # We could potentially accept a tuple (variables, constraints).
+            # TODO: Disallow kwargs if this type of "model" is provided?
+            nx_graph, variables, constraints = model
+            self._variables = list(variables)
+            self._constraints = list(constraints)
+            self._var_index_map = ComponentMap(
+                (var, i) for i, var in enumerate(self._variables)
+            )
+            self._con_index_map = ComponentMap(
+                (con, i) for i, con in enumerate(self._constraints)
+            )
+            # For now, don't check any properties of this graph. We could check
+            # for a bipartition that matches the variable and constraint lists.
+            self._incidence_graph = nx_graph
         else:
             raise TypeError(
                 "Unsupported type for incidence graph. Expected PyomoNLP"
-                " or _BlockData but got %s." % type(model)
+                " or BlockData but got %s." % type(model)
             )
 
     @property
@@ -438,11 +453,29 @@ def _validate_input(self, variables, constraints):
                 raise ValueError("Neither variables nor a model have been provided.")
             else:
                 variables = self.variables
+        elif self._incidence_graph is not None:
+            # If variables were provided and an incidence graph is cached,
+            # make sure the provided variables exist in the graph.
+            for var in variables:
+                if var not in self._var_index_map:
+                    raise KeyError(
+                        f"Variable {var} does not exist in the cached"
+                        " incidence graph."
+                    )
         if constraints is None:
             if self._incidence_graph is None:
                 raise ValueError("Neither constraints nor a model have been provided.")
             else:
                 constraints = self.constraints
+        elif self._incidence_graph is not None:
+            # If constraints were provided and an incidence graph is cached,
+            # make sure the provided constraints exist in the graph.
+            for con in constraints:
+                if con not in self._con_index_map:
+                    raise KeyError(
+                        f"Constraint {con} does not exist in the cached"
+                        " incidence graph."
+                    )
 
         _check_unindexed(variables + constraints)
         return variables, constraints
@@ -464,6 +497,25 @@ def _extract_subgraph(self, variables, constraints):
             )
             return subgraph
 
+    def subgraph(self, variables, constraints):
+        """Extract a subgraph defined by the provided variables and constraints
+
+        Underlying data structures are copied, and constraints are not reinspected
+        for incidence variables (the edges from this incidence graph are used).
+
+        Returns
+        -------
+        ``IncidenceGraphInterface``
+            A new incidence graph containing only the specified variables and
+            constraints, and the edges between pairs thereof.
+
+        """
+        nx_subgraph = self._extract_subgraph(variables, constraints)
+        subgraph = IncidenceGraphInterface(
+            (nx_subgraph, variables, constraints), **self._config
+        )
+        return subgraph
+
     @property
     def incidence_matrix(self):
         """The structural incidence matrix of variables and constraints.
@@ -820,7 +872,7 @@ def dulmage_mendelsohn(self, variables=None, constraints=None):
         # Hopefully this does not get too confusing...
         return var_partition, con_partition
 
-    def remove_nodes(self, nodes, constraints=None):
+    def remove_nodes(self, variables=None, constraints=None):
         """Removes the specified variables and constraints (columns and
         rows) from the cached incidence matrix.
 
@@ -832,35 +884,76 @@ def remove_nodes(self, nodes, constraints=None):
 
         Parameters
         ----------
-        nodes: list
-            VarData or ConData objects whose columns or rows will be
-            removed from the incidence matrix.
+        variables: list
+            VarData objects whose nodes will be removed from the incidence graph
         constraints: list
-            VarData or ConData objects whose columns or rows will be
-            removed from the incidence matrix.
+            ConData objects whose nodes will be removed from the incidence graph
+
+        .. note::
+
+           **Deprecation in Pyomo v6.7.2**
+
+           The pre-6.7.2 implementation of ``remove_nodes`` allowed variables and
+           constraints to remove to be specified in a single list. This made
+           error checking difficult, and indeed, if invalid components were
+           provided, we carried on silently instead of throwing an error or
+           warning. As part of a fix to raise an error if an invalid component
+           (one that is not part of the incidence graph) is provided, we now require
+           variables and constraints to be specified separately.
 
         """
         if constraints is None:
             constraints = []
+        if variables is None:
+            variables = []
         if self._incidence_graph is None:
             raise RuntimeError(
                 "Attempting to remove variables and constraints from cached "
                 "incidence matrix,\nbut no incidence matrix has been cached."
             )
-        to_exclude = ComponentSet(nodes)
-        to_exclude.update(constraints)
-        vars_to_include = [v for v in self.variables if v not in to_exclude]
-        cons_to_include = [c for c in self.constraints if c not in to_exclude]
+
+        vars_to_validate = []
+        cons_to_validate = []
+        depr_msg = (
+            "In IncidenceGraphInterface.remove_nodes, passing variables and"
+            " constraints in the same list is deprecated. Please separate your"
+            " variables and constraints and pass them in the order variables,"
+            " constraints."
+        )
+        if any(var in self._con_index_map for var in variables) or any(
+            con in self._var_index_map for con in constraints
+        ):
+            deprecation_warning(depr_msg, version="6.7.2")
+        # If we received variables/constraints in the same list, sort them.
+        # Any unrecognized objects will be caught by _validate_input.
+        for var in variables:
+            if var in self._con_index_map:
+                cons_to_validate.append(var)
+            else:
+                vars_to_validate.append(var)
+        for con in constraints:
+            if con in self._var_index_map:
+                vars_to_validate.append(con)
+            else:
+                cons_to_validate.append(con)
+
+        variables, constraints = self._validate_input(
+            vars_to_validate, cons_to_validate
+        )
+        v_exclude = ComponentSet(variables)
+        c_exclude = ComponentSet(constraints)
+        vars_to_include = [v for v in self.variables if v not in v_exclude]
+        cons_to_include = [c for c in self.constraints if c not in c_exclude]
         incidence_graph = self._extract_subgraph(vars_to_include, cons_to_include)
         # update attributes
         self._variables = vars_to_include
         self._constraints = cons_to_include
         self._incidence_graph = incidence_graph
         self._var_index_map = ComponentMap(
-            (var, i) for i, var in enumerate(self.variables)
+            (var, i) for i, var in enumerate(vars_to_include)
         )
         self._con_index_map = ComponentMap(
-            (con, i) for i, con in enumerate(self._constraints)
+            (con, i) for i, con in enumerate(cons_to_include)
         )
 
     def plot(self, variables=None, constraints=None, title=None, show=True):
@@ -886,9 +979,9 @@ def plot(self, variables=None, constraints=None, title=None, show=True):
         edge_trace = plotly.graph_objects.Scatter(
             x=edge_x,
             y=edge_y,
-            line=dict(width=0.5, color='#888'),
-            hoverinfo='none',
-            mode='lines',
+            line=dict(width=0.5, color="#888"),
+            hoverinfo="none",
+            mode="lines",
         )
 
         node_x = []
@@ -902,28 +995,28 @@ def plot(self, variables=None, constraints=None, title=None, show=True):
             if node < M:
                 # According to convention, we are a constraint node
                 c = constraints[node]
-                node_color.append('red')
-                body_text = '<br>'.join(
+                node_color.append("red")
+                body_text = "<br>".join(
                     textwrap.wrap(str(c.body), width=120, subsequent_indent="    ")
                 )
                 node_text.append(
-                    f'{str(c)}<br>lb: {str(c.lower)}<br>body: {body_text}<br>'
-                    f'ub: {str(c.upper)}<br>active: {str(c.active)}'
+                    f"{str(c)}<br>lb: {str(c.lower)}<br>body: {body_text}<br>"
+                    f"ub: {str(c.upper)}<br>active: {str(c.active)}"
                 )
             else:
                 # According to convention, we are a variable node
                 v = variables[node - M]
-                node_color.append('blue')
+                node_color.append("blue")
                 node_text.append(
-                    f'{str(v)}<br>lb: {str(v.lb)}<br>ub: {str(v.ub)}<br>'
-                    f'value: {str(v.value)}<br>domain: {str(v.domain)}<br>'
-                    f'fixed: {str(v.is_fixed())}'
+                    f"{str(v)}<br>lb: {str(v.lb)}<br>ub: {str(v.ub)}<br>"
+                    f"value: {str(v.value)}<br>domain: {str(v.domain)}<br>"
+                    f"fixed: {str(v.is_fixed())}"
                 )
         node_trace = plotly.graph_objects.Scatter(
             x=node_x,
             y=node_y,
-            mode='markers',
-            hoverinfo='text',
+            mode="markers",
+            hoverinfo="text",
             text=node_text,
             marker=dict(color=node_color, size=10),
         )
@@ -932,3 +1025,32 @@ def plot(self, variables=None, constraints=None, title=None, show=True):
             fig.update_layout(title=dict(text=title))
         if show:
             fig.show()
+
+    def add_edge(self, variable, constraint):
+        """Adds an edge between variable and constraint in the incidence graph
+
+        Parameters
+        ----------
+        variable: VarData
+            A variable in the graph
+        constraint: ConstraintData
+            A constraint in the graph
+        """
+        if self._incidence_graph is None:
+            raise RuntimeError(
+                "Attempting to add edge in an incidence graph from cached "
+                "incidence graph,\nbut no incidence graph has been cached."
+            )
+
+        if variable not in self._var_index_map:
+            raise RuntimeError("%s is not a variable in the incidence graph" % variable)
+
+        if constraint not in self._con_index_map:
+            raise RuntimeError(
+                "%s is not a constraint in the incidence graph" % constraint
+            )
+
+        var_id = self._var_index_map[variable] + len(self._con_index_map)
+        con_id = self._con_index_map[constraint]
+
+        self._incidence_graph.add_edge(var_id, con_id)
diff --git a/pyomo/contrib/incidence_analysis/matching.py b/pyomo/contrib/incidence_analysis/matching.py
index 14b3cd5b18d..e37b35cd973 100644
--- a/pyomo/contrib/incidence_analysis/matching.py
+++ b/pyomo/contrib/incidence_analysis/matching.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/incidence_analysis/scc_solver.py b/pyomo/contrib/incidence_analysis/scc_solver.py
index d7620278fd3..db201dccb0a 100644
--- a/pyomo/contrib/incidence_analysis/scc_solver.py
+++ b/pyomo/contrib/incidence_analysis/scc_solver.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -18,15 +18,16 @@
     IncidenceGraphInterface,
     _generate_variables_in_constraints,
 )
+from pyomo.contrib.incidence_analysis.config import IncidenceMethod
 
 
 _log = logging.getLogger(__name__)
 
 
 def generate_strongly_connected_components(
-    constraints, variables=None, include_fixed=False
+    constraints, variables=None, include_fixed=False, igraph=None
 ):
-    """Yield in order ``_BlockData`` that each contain the variables and
+    """Yield in order ``BlockData`` that each contain the variables and
     constraints of a single diagonal block in a block lower triangularization
     of the incidence matrix of constraints and variables
 
@@ -41,13 +42,16 @@ def generate_strongly_connected_components(
     variables: List of Pyomo variable data objects
         Variables that may participate in strongly connected components.
         If not provided, all variables in the constraints will be used.
-    include_fixed: Bool
+    include_fixed: Bool, optional
         Indicates whether fixed variables will be included when
         identifying variables in constraints.
+    igraph: IncidenceGraphInterface, optional
+        Incidence graph containing (at least) the provided constraints
+        and variables.
 
     Yields
     ------
-    Tuple of ``_BlockData``, list-of-variables
+    Tuple of ``BlockData``, list-of-variables
         Blocks containing the variables and constraints of every strongly
         connected component, in a topological order. The variables are the
         "input variables" for that block.
@@ -55,11 +59,24 @@ def generate_strongly_connected_components(
     """
     if variables is None:
         variables = list(
-            _generate_variables_in_constraints(constraints, include_fixed=include_fixed)
+            _generate_variables_in_constraints(
+                constraints,
+                include_fixed=include_fixed,
+                method=IncidenceMethod.ampl_repn,
+            )
         )
 
-    assert len(variables) == len(constraints)
-    igraph = IncidenceGraphInterface()
+    if len(variables) != len(constraints):
+        nvar = len(variables)
+        ncon = len(constraints)
+        raise RuntimeError(
+            "generate_strongly_connected_components only supports systems with the"
+            f" same numbers of variables and equality constraints. Got {nvar}"
+            f" variables and {ncon} constraints."
+        )
+    if igraph is None:
+        igraph = IncidenceGraphInterface()
+
     var_blocks, con_blocks = igraph.block_triangularize(
         variables=variables, constraints=constraints
     )
@@ -68,12 +85,14 @@ def generate_strongly_connected_components(
         subsets, include_fixed=include_fixed
     ):
         # TODO: How does len scale for reference-to-list?
+        # If this assert fails, it may be due to a bug in block_triangularize
+        # or generate_subsystem_block.
         assert len(block.vars) == len(block.cons)
         yield (block, inputs)
 
 
 def solve_strongly_connected_components(
-    block, solver=None, solve_kwds=None, calc_var_kwds=None
+    block, *, solver=None, solve_kwds=None, use_calc_var=True, calc_var_kwds=None
 ):
     """Solve a square system of variables and equality constraints by
     solving strongly connected components individually.
@@ -98,6 +117,9 @@ def solve_strongly_connected_components(
         a solve method.
     solve_kwds: Dictionary
         Keyword arguments for the solver's solve method
+    use_calc_var: Bool
+        Whether to use ``calculate_variable_from_constraint`` for one-by-one
+        square system solves
     calc_var_kwds: Dictionary
         Keyword arguments for calculate_variable_from_constraint
 
@@ -112,23 +134,28 @@ def solve_strongly_connected_components(
         calc_var_kwds = {}
 
     igraph = IncidenceGraphInterface(
-        block, active=True, include_fixed=False, include_inequality=False
+        block,
+        active=True,
+        include_fixed=False,
+        include_inequality=False,
+        method=IncidenceMethod.ampl_repn,
     )
     constraints = igraph.constraints
     variables = igraph.variables
 
     res_list = []
     log_blocks = _log.isEnabledFor(logging.DEBUG)
-    for scc, inputs in generate_strongly_connected_components(constraints, variables):
-        with TemporarySubsystemManager(to_fix=inputs):
+    for scc, inputs in generate_strongly_connected_components(
+        constraints, variables, igraph=igraph
+    ):
+        with TemporarySubsystemManager(to_fix=inputs, remove_bounds_on_fix=True):
             N = len(scc.vars)
-            if N == 1:
+            if N == 1 and use_calc_var:
                 if log_blocks:
                     _log.debug(f"Solving 1x1 block: {scc.cons[0].name}.")
                 results = calculate_variable_from_constraint(
                     scc.vars[0], scc.cons[0], **calc_var_kwds
                 )
-                res_list.append(results)
             else:
                 if solver is None:
                     var_names = [var.name for var in scc.vars.values()][:10]
@@ -142,5 +169,5 @@ def solve_strongly_connected_components(
                 if log_blocks:
                     _log.debug(f"Solving {N}x{N} block.")
                 results = solver.solve(scc, **solve_kwds)
-                res_list.append(results)
+            res_list.append(results)
     return res_list
diff --git a/pyomo/contrib/incidence_analysis/tests/__init__.py b/pyomo/contrib/incidence_analysis/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/incidence_analysis/tests/__init__.py
+++ b/pyomo/contrib/incidence_analysis/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/incidence_analysis/tests/models_for_testing.py b/pyomo/contrib/incidence_analysis/tests/models_for_testing.py
index 98d61201619..6040e80e068 100644
--- a/pyomo/contrib/incidence_analysis/tests/models_for_testing.py
+++ b/pyomo/contrib/incidence_analysis/tests/models_for_testing.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/incidence_analysis/tests/test_connected.py b/pyomo/contrib/incidence_analysis/tests/test_connected.py
index a937a5029a1..421231d3dd0 100644
--- a/pyomo/contrib/incidence_analysis/tests/test_connected.py
+++ b/pyomo/contrib/incidence_analysis/tests/test_connected.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/incidence_analysis/tests/test_dulmage_mendelsohn.py b/pyomo/contrib/incidence_analysis/tests/test_dulmage_mendelsohn.py
index 98fefea2d80..6195d6afca7 100644
--- a/pyomo/contrib/incidence_analysis/tests/test_dulmage_mendelsohn.py
+++ b/pyomo/contrib/incidence_analysis/tests/test_dulmage_mendelsohn.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/incidence_analysis/tests/test_incidence.py b/pyomo/contrib/incidence_analysis/tests/test_incidence.py
index 7f57dd904a7..832fbbfb10c 100644
--- a/pyomo/contrib/incidence_analysis/tests/test_incidence.py
+++ b/pyomo/contrib/incidence_analysis/tests/test_incidence.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -56,44 +56,56 @@ def test_basic_incidence(self):
 
     def test_incidence_with_fixed_variable(self):
         m = pyo.ConcreteModel()
-        m.x = pyo.Var([1, 2, 3])
+        m.x = pyo.Var([1, 2, 3], initialize=1.0)
         expr = m.x[1] + m.x[1] * m.x[2] + m.x[1] * pyo.exp(m.x[3])
         m.x[2].fix()
         variables = self._get_incident_variables(expr)
         var_set = ComponentSet(variables)
         self.assertEqual(var_set, ComponentSet([m.x[1], m.x[3]]))
 
-    def test_incidence_with_mutable_parameter(self):
+    def test_incidence_with_named_expression(self):
         m = pyo.ConcreteModel()
         m.x = pyo.Var([1, 2, 3])
-        m.p = pyo.Param(mutable=True, initialize=None)
-        expr = m.x[1] + m.p * m.x[1] * m.x[2] + m.x[1] * pyo.exp(m.x[3])
+        m.subexpr = pyo.Expression(pyo.Integers)
+        m.subexpr[1] = m.x[1] * pyo.exp(m.x[3])
+        expr = m.x[1] + m.x[1] * m.x[2] + m.subexpr[1]
         variables = self._get_incident_variables(expr)
         self.assertEqual(ComponentSet(variables), ComponentSet(m.x[:]))
 
 
-class TestIncidenceStandardRepn(unittest.TestCase, _TestIncidence):
-    def _get_incident_variables(self, expr, **kwds):
-        method = IncidenceMethod.standard_repn
-        return get_incident_variables(expr, method=method, **kwds)
+class _TestIncidenceLinearOnly(object):
+    """Tests for methods that support linear_only"""
 
-    def test_assumed_standard_repn_behavior(self):
+    def _get_incident_variables(self, expr):
+        raise NotImplementedError(
+            "_TestIncidenceLinearOnly should not be used directly"
+        )
+
+    def test_linear_only(self):
         m = pyo.ConcreteModel()
-        m.x = pyo.Var([1, 2])
-        m.p = pyo.Param(initialize=0.0)
+        m.x = pyo.Var([1, 2, 3])
 
-        # We rely on variables with constant coefficients of zero not appearing
-        # in the standard repn (as opposed to appearing with explicit
-        # coefficients of zero).
-        expr = m.x[1] + 0 * m.x[2]
-        repn = generate_standard_repn(expr)
-        self.assertEqual(len(repn.linear_vars), 1)
-        self.assertIs(repn.linear_vars[0], m.x[1])
+        expr = 2 * m.x[1] + 4 * m.x[2] * m.x[1] - m.x[1] * pyo.exp(m.x[3])
+        variables = self._get_incident_variables(expr, linear_only=True)
+        self.assertEqual(len(variables), 0)
 
-        expr = m.p * m.x[1] + m.x[2]
-        repn = generate_standard_repn(expr)
-        self.assertEqual(len(repn.linear_vars), 1)
-        self.assertIs(repn.linear_vars[0], m.x[2])
+        expr = 2 * m.x[1] + 2 * m.x[2] * m.x[3] + 3 * m.x[2]
+        variables = self._get_incident_variables(expr, linear_only=True)
+        self.assertEqual(ComponentSet(variables), ComponentSet([m.x[1]]))
+
+        m.x[3].fix(2.5)
+        expr = 2 * m.x[1] + 2 * m.x[2] * m.x[3] + 3 * m.x[2]
+        variables = self._get_incident_variables(expr, linear_only=True)
+        self.assertEqual(ComponentSet(variables), ComponentSet([m.x[1], m.x[2]]))
+
+
+class _TestIncidenceLinearCancellation(object):
+    """Tests for methods that perform linear cancellation"""
+
+    def _get_incident_variables(self, expr):
+        raise NotImplementedError(
+            "_TestIncidenceLinearCancellation should not be used directly"
+        )
 
     def test_zero_coef(self):
         m = pyo.ConcreteModel()
@@ -113,23 +125,6 @@ def test_variable_minus_itself(self):
         var_set = ComponentSet(variables)
         self.assertEqual(var_set, ComponentSet([m.x[2], m.x[3]]))
 
-    def test_linear_only(self):
-        m = pyo.ConcreteModel()
-        m.x = pyo.Var([1, 2, 3])
-
-        expr = 2 * m.x[1] + 4 * m.x[2] * m.x[1] - m.x[1] * pyo.exp(m.x[3])
-        variables = self._get_incident_variables(expr, linear_only=True)
-        self.assertEqual(len(variables), 0)
-
-        expr = 2 * m.x[1] + 2 * m.x[2] * m.x[3] + 3 * m.x[2]
-        variables = self._get_incident_variables(expr, linear_only=True)
-        self.assertEqual(ComponentSet(variables), ComponentSet([m.x[1]]))
-
-        m.x[3].fix(2.5)
-        expr = 2 * m.x[1] + 2 * m.x[2] * m.x[3] + 3 * m.x[2]
-        variables = self._get_incident_variables(expr, linear_only=True)
-        self.assertEqual(ComponentSet(variables), ComponentSet([m.x[1], m.x[2]]))
-
     def test_fixed_zero_linear_coefficient(self):
         m = pyo.ConcreteModel()
         m.x = pyo.Var([1, 2, 3])
@@ -148,6 +143,9 @@ def test_fixed_zero_linear_coefficient(self):
         variables = self._get_incident_variables(expr)
         self.assertEqual(ComponentSet(variables), ComponentSet([m.x[1], m.x[2]]))
 
+    # NOTE: This test assumes that all methods that support linear cancellation
+    # accept a linear_only argument. If this changes, this test will need to be
+    # moved.
     def test_fixed_zero_coefficient_linear_only(self):
         m = pyo.ConcreteModel()
         m.x = pyo.Var([1, 2, 3])
@@ -159,6 +157,35 @@ def test_fixed_zero_coefficient_linear_only(self):
         self.assertEqual(len(variables), 1)
         self.assertIs(variables[0], m.x[3])
 
+
+class TestIncidenceStandardRepn(
+    unittest.TestCase,
+    _TestIncidence,
+    _TestIncidenceLinearOnly,
+    _TestIncidenceLinearCancellation,
+):
+    def _get_incident_variables(self, expr, **kwds):
+        method = IncidenceMethod.standard_repn
+        return get_incident_variables(expr, method=method, **kwds)
+
+    def test_assumed_standard_repn_behavior(self):
+        m = pyo.ConcreteModel()
+        m.x = pyo.Var([1, 2])
+        m.p = pyo.Param(initialize=0.0)
+
+        # We rely on variables with constant coefficients of zero not appearing
+        # in the standard repn (as opposed to appearing with explicit
+        # coefficients of zero).
+        expr = m.x[1] + 0 * m.x[2]
+        repn = generate_standard_repn(expr)
+        self.assertEqual(len(repn.linear_vars), 1)
+        self.assertIs(repn.linear_vars[0], m.x[1])
+
+        expr = m.p * m.x[1] + m.x[2]
+        repn = generate_standard_repn(expr)
+        self.assertEqual(len(repn.linear_vars), 1)
+        self.assertIs(repn.linear_vars[0], m.x[2])
+
     def test_fixed_none_linear_coefficient(self):
         m = pyo.ConcreteModel()
         m.x = pyo.Var([1, 2, 3])
@@ -168,6 +195,14 @@ def test_fixed_none_linear_coefficient(self):
         variables = self._get_incident_variables(expr)
         self.assertEqual(ComponentSet(variables), ComponentSet([m.x[1], m.x[2]]))
 
+    def test_incidence_with_mutable_parameter(self):
+        m = pyo.ConcreteModel()
+        m.x = pyo.Var([1, 2, 3])
+        m.p = pyo.Param(mutable=True, initialize=None)
+        expr = m.x[1] + m.p * m.x[1] * m.x[2] + m.x[1] * pyo.exp(m.x[3])
+        variables = self._get_incident_variables(expr)
+        self.assertEqual(ComponentSet(variables), ComponentSet(m.x[:]))
+
 
 class TestIncidenceIdentifyVariables(unittest.TestCase, _TestIncidence):
     def _get_incident_variables(self, expr, **kwds):
@@ -192,6 +227,36 @@ def test_variable_minus_itself(self):
         var_set = ComponentSet(variables)
         self.assertEqual(var_set, ComponentSet(m.x[:]))
 
+    def test_incidence_with_mutable_parameter(self):
+        m = pyo.ConcreteModel()
+        m.x = pyo.Var([1, 2, 3])
+        m.p = pyo.Param(mutable=True, initialize=None)
+        expr = m.x[1] + m.p * m.x[1] * m.x[2] + m.x[1] * pyo.exp(m.x[3])
+        variables = self._get_incident_variables(expr)
+        self.assertEqual(ComponentSet(variables), ComponentSet(m.x[:]))
+
+
+class TestIncidenceAmplRepn(
+    unittest.TestCase,
+    _TestIncidence,
+    _TestIncidenceLinearOnly,
+    _TestIncidenceLinearCancellation,
+):
+    def _get_incident_variables(self, expr, **kwds):
+        method = IncidenceMethod.ampl_repn
+        return get_incident_variables(expr, method=method, **kwds)
+
+
+class TestIncidenceStandardRepnComputeValues(
+    unittest.TestCase,
+    _TestIncidence,
+    _TestIncidenceLinearOnly,
+    _TestIncidenceLinearCancellation,
+):
+    def _get_incident_variables(self, expr, **kwds):
+        method = IncidenceMethod.standard_repn_compute_values
+        return get_incident_variables(expr, method=method, **kwds)
+
 
 if __name__ == "__main__":
     unittest.main()
diff --git a/pyomo/contrib/incidence_analysis/tests/test_interface.py b/pyomo/contrib/incidence_analysis/tests/test_interface.py
index 490ea94f63c..9957e78168b 100644
--- a/pyomo/contrib/incidence_analysis/tests/test_interface.py
+++ b/pyomo/contrib/incidence_analysis/tests/test_interface.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -634,17 +634,15 @@ def test_exception(self):
         nlp = PyomoNLP(model)
         igraph = IncidenceGraphInterface(nlp)
 
-        with self.assertRaises(RuntimeError) as exc:
+        with self.assertRaisesRegex(KeyError, "does not exist"):
             variables = [model.P]
             constraints = [model.ideal_gas]
             igraph.maximum_matching(variables, constraints)
-        self.assertIn('must be unindexed', str(exc.exception))
 
-        with self.assertRaises(RuntimeError) as exc:
+        with self.assertRaisesRegex(KeyError, "does not exist"):
             variables = [model.P]
             constraints = [model.ideal_gas]
             igraph.block_triangularize(variables, constraints)
-        self.assertIn('must be unindexed', str(exc.exception))
 
 
 @unittest.skipUnless(networkx_available, "networkx is not available.")
@@ -885,17 +883,15 @@ def test_exception(self):
         model = make_gas_expansion_model()
         igraph = IncidenceGraphInterface(model)
 
-        with self.assertRaises(RuntimeError) as exc:
+        with self.assertRaisesRegex(KeyError, "does not exist"):
             variables = [model.P]
             constraints = [model.ideal_gas]
             igraph.maximum_matching(variables, constraints)
-        self.assertIn('must be unindexed', str(exc.exception))
 
-        with self.assertRaises(RuntimeError) as exc:
+        with self.assertRaisesRegex(KeyError, "does not exist"):
             variables = [model.P]
             constraints = [model.ideal_gas]
             igraph.block_triangularize(variables, constraints)
-        self.assertIn('must be unindexed', str(exc.exception))
 
     @unittest.skipUnless(scipy_available, "scipy is not available.")
     def test_remove(self):
@@ -923,7 +919,7 @@ def test_remove(self):
         # Say we know that these variables and constraints should
         # be matched...
         vars_to_remove = [model.F[0], model.F[2]]
-        cons_to_remove = (model.mbal[1], model.mbal[2])
+        cons_to_remove = [model.mbal[1], model.mbal[2]]
         igraph.remove_nodes(vars_to_remove, cons_to_remove)
         variable_set = ComponentSet(igraph.variables)
         self.assertNotIn(model.F[0], variable_set)
@@ -1309,7 +1305,7 @@ def test_remove(self):
         # matrix.
         vars_to_remove = [m.flow_comp[1]]
         cons_to_remove = [m.flow_eqn[1]]
-        igraph.remove_nodes(vars_to_remove + cons_to_remove)
+        igraph.remove_nodes(vars_to_remove, cons_to_remove)
         var_dmp, con_dmp = igraph.dulmage_mendelsohn()
         var_con_set = ComponentSet(igraph.variables + igraph.constraints)
         underconstrained_set = ComponentSet(
@@ -1460,6 +1456,42 @@ def test_remove_no_matrix(self):
         with self.assertRaisesRegex(RuntimeError, "no incidence matrix"):
             igraph.remove_nodes([m.v1])
 
+    def test_remove_bad_node(self):
+        m = pyo.ConcreteModel()
+        m.x = pyo.Var([1, 2, 3])
+        m.eq = pyo.Constraint(pyo.PositiveIntegers)
+        m.eq[1] = m.x[1] * m.x[2] == m.x[3]
+        m.eq[2] = m.x[1] + 2 * m.x[2] == 3 * m.x[3]
+        igraph = IncidenceGraphInterface(m)
+        with self.assertRaisesRegex(KeyError, "does not exist"):
+            # Suppose we think something like this should work. We should get
+            # an error, and not silently do nothing.
+            igraph.remove_nodes([m.x], [m.eq[1]])
+
+        with self.assertRaisesRegex(KeyError, "does not exist"):
+            igraph.remove_nodes(None, [m.eq])
+
+        with self.assertRaisesRegex(KeyError, "does not exist"):
+            igraph.remove_nodes([[m.x[1], m.x[2]], [m.eq[1]]])
+
+    def test_remove_varcon_samelist_deprecated(self):
+        m = pyo.ConcreteModel()
+        m.x = pyo.Var([1, 2, 3])
+        m.eq = pyo.Constraint(pyo.PositiveIntegers)
+        m.eq[1] = m.x[1] * m.x[2] == m.x[3]
+        m.eq[2] = m.x[1] + 2 * m.x[2] == 3 * m.x[3]
+
+        igraph = IncidenceGraphInterface(m)
+        # This raises a deprecation warning. When the deprecated functionality
+        # is removed, this will fail, and this test should be updated accordingly.
+        igraph.remove_nodes([m.eq[1], m.x[1]])
+        self.assertEqual(len(igraph.variables), 2)
+        self.assertEqual(len(igraph.constraints), 1)
+
+        igraph.remove_nodes([], [m.eq[2], m.x[2]])
+        self.assertEqual(len(igraph.variables), 1)
+        self.assertEqual(len(igraph.constraints), 0)
+
 
 @unittest.skipUnless(networkx_available, "networkx is not available.")
 @unittest.skipUnless(scipy_available, "scipy is not available.")
@@ -1653,11 +1685,11 @@ def test_extract_exceptions(self):
 
         sg_cons = [0, 2, 5]
         sg_vars = [i + len(constraints) for i in [2, 3]]
-        msg = "Subgraph is not bipartite"
+        msg = "Invalid bipartite sets."
         with self.assertRaisesRegex(RuntimeError, msg):
             subgraph = extract_bipartite_subgraph(graph, sg_cons, sg_vars)
 
-        sg_cons = [0, 2, 5]
+        sg_cons = [0, 2, 0]
         sg_vars = [i + len(constraints) for i in [2, 0, 3]]
         msg = "provided more than once"
         with self.assertRaisesRegex(RuntimeError, msg):
@@ -1745,7 +1777,7 @@ def test_plot(self):
         m.c2 = pyo.Constraint(expr=m.z >= m.x)
         m.y.fix()
         igraph = IncidenceGraphInterface(m, include_inequality=True, include_fixed=True)
-        igraph.plot(title='test plot', show=False)
+        igraph.plot(title="test plot", show=False)
 
     def test_zero_coeff(self):
         m = pyo.ConcreteModel()
@@ -1791,6 +1823,91 @@ def test_linear_only(self):
         self.assertIs(matching[m.eq2], m.x[2])
         self.assertIs(matching[m.eq3], m.x[3])
 
+    def test_add_edge(self):
+        m = pyo.ConcreteModel()
+        m.x = pyo.Var([1, 2, 3, 4])
+        m.eq1 = pyo.Constraint(expr=m.x[1] ** 2 + m.x[2] ** 2 + m.x[3] ** 2 == 1)
+        m.eq2 = pyo.Constraint(expr=m.x[2] + pyo.sqrt(m.x[1]) + pyo.exp(m.x[3]) == 1)
+        m.eq3 = pyo.Constraint(expr=m.x[3] + m.x[2] + m.x[4] == 1)
+        m.eq4 = pyo.Constraint(expr=m.x[1] + m.x[2] ** 2 == 5)
+
+        igraph = IncidenceGraphInterface(m, linear_only=False)
+        n_edges_original = igraph.n_edges
+
+        # Test edge is added between previously unconnected nodes
+        igraph.add_edge(m.x[1], m.eq3)
+        n_edges_new = igraph.n_edges
+        assert ComponentSet(igraph.get_adjacent_to(m.eq3)) == ComponentSet(m.x[:])
+        self.assertEqual(n_edges_original + 1, n_edges_new)
+
+        # Test no edge is added if there exists a previous edge between nodes
+        igraph.add_edge(m.x[2], m.eq3)
+        n_edges2 = igraph.n_edges
+        self.assertEqual(n_edges_new, n_edges2)
+
+    def test_add_edge_linear_igraph(self):
+        m = pyo.ConcreteModel()
+        m.x = pyo.Var([1, 2, 3, 4])
+        m.eq1 = pyo.Constraint(expr=m.x[1] + m.x[3] == 1)
+        m.eq2 = pyo.Constraint(expr=m.x[2] + pyo.sqrt(m.x[1]) + pyo.exp(m.x[3]) == 1)
+        m.eq3 = pyo.Constraint(expr=m.x[4] ** 2 + m.x[1] ** 3 + m.x[2] ** 2 == 1)
+
+        # Make sure error is raised when a variable is not in the igraph
+        igraph = IncidenceGraphInterface(m, linear_only=True)
+
+        msg = "is not a variable in the incidence graph"
+        with self.assertRaisesRegex(RuntimeError, msg):
+            igraph.add_edge(m.x[4], m.eq2)
+
+    def test_var_elim(self):
+        m = pyo.ConcreteModel()
+        m.x = pyo.Var([1, 2, 3, 4])
+        m.eq1 = pyo.Constraint(expr=m.x[1] ** 2 + m.x[2] ** 2 + m.x[3] ** 2 == 1)
+        m.eq2 = pyo.Constraint(expr=pyo.sqrt(m.x[1]) + pyo.exp(m.x[3]) == 1)
+        m.eq3 = pyo.Constraint(expr=m.x[3] + m.x[2] + m.x[4] == 1)
+        m.eq4 = pyo.Constraint(expr=m.x[1] == 5 * m.x[2])
+
+        igraph = IncidenceGraphInterface(m)
+        # Eliminate x[1] using eq4
+        for adj_con in igraph.get_adjacent_to(m.x[1]):
+            for adj_var in igraph.get_adjacent_to(m.eq4):
+                igraph.add_edge(adj_var, adj_con)
+        igraph.remove_nodes([m.x[1]], [m.eq4])
+
+        assert ComponentSet(igraph.variables) == ComponentSet([m.x[2], m.x[3], m.x[4]])
+        assert ComponentSet(igraph.constraints) == ComponentSet([m.eq1, m.eq2, m.eq3])
+        self.assertEqual(7, igraph.n_edges)
+
+        assert m.x[2] in ComponentSet(igraph.get_adjacent_to(m.eq1))
+        assert m.x[2] in ComponentSet(igraph.get_adjacent_to(m.eq2))
+
+    def test_subgraph(self):
+        m = pyo.ConcreteModel()
+        m.I = pyo.Set(initialize=[1, 2, 3, 4])
+        m.v = pyo.Var(m.I, bounds=(0, None))
+        m.eq1 = pyo.Constraint(expr=m.v[1] ** 2 + m.v[2] ** 2 == 1.0)
+        m.eq2 = pyo.Constraint(expr=m.v[1] + 2.0 == m.v[3])
+        m.ineq1 = pyo.Constraint(expr=m.v[2] - m.v[3] ** 0.5 + m.v[4] ** 2 <= 1.0)
+        m.ineq2 = pyo.Constraint(expr=m.v[2] * m.v[4] >= 1.0)
+        m.ineq3 = pyo.Constraint(expr=m.v[1] >= m.v[4] ** 4)
+        m.obj = pyo.Objective(expr=-m.v[1] - m.v[2] + m.v[3] ** 2 + m.v[4] ** 2)
+        igraph = IncidenceGraphInterface(m)
+        eq_igraph = igraph.subgraph(igraph.variables, [m.eq1, m.eq2])
+        for i in range(len(igraph.variables)):
+            self.assertIs(igraph.variables[i], eq_igraph.variables[i])
+        self.assertEqual(
+            ComponentSet(eq_igraph.constraints), ComponentSet([m.eq1, m.eq2])
+        )
+
+        subgraph = eq_igraph.subgraph([m.v[1], m.v[3]], [m.eq1, m.eq2])
+        self.assertEqual(
+            ComponentSet(subgraph.get_adjacent_to(m.eq2)),
+            ComponentSet([m.v[1], m.v[3]]),
+        )
+        self.assertEqual(
+            ComponentSet(subgraph.get_adjacent_to(m.eq1)), ComponentSet([m.v[1]])
+        )
+
 
 @unittest.skipUnless(networkx_available, "networkx is not available.")
 class TestIndexedBlock(unittest.TestCase):
@@ -1803,7 +1920,7 @@ def test_block_data_obj(self):
         self.assertEqual(len(var_dmp.unmatched), 1)
         self.assertEqual(len(con_dmp.unmatched), 1)
 
-        msg = "Unsupported type.*_BlockData"
+        msg = "Unsupported type.*BlockData"
         with self.assertRaisesRegex(TypeError, msg):
             igraph = IncidenceGraphInterface(m.block)
 
diff --git a/pyomo/contrib/incidence_analysis/tests/test_matching.py b/pyomo/contrib/incidence_analysis/tests/test_matching.py
index b5550b3b84c..2327439f0a2 100644
--- a/pyomo/contrib/incidence_analysis/tests/test_matching.py
+++ b/pyomo/contrib/incidence_analysis/tests/test_matching.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/incidence_analysis/tests/test_scc_solver.py b/pyomo/contrib/incidence_analysis/tests/test_scc_solver.py
index 6efe52a7d80..ef4853d7e9a 100644
--- a/pyomo/contrib/incidence_analysis/tests/test_scc_solver.py
+++ b/pyomo/contrib/incidence_analysis/tests/test_scc_solver.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -501,5 +501,22 @@ def test_with_inequalities(self):
         self.assertEqual(m.x[3].value, 1.0)
 
 
+@unittest.skipUnless(scipy_available, "SciPy is not available")
+@unittest.skipUnless(networkx_available, "NetworkX is not available")
+class TestExceptions(unittest.TestCase):
+    def test_nonsquare_system(self):
+        m = pyo.ConcreteModel()
+        m.x = pyo.Var([1, 2], initialize=1)
+        m.eq = pyo.Constraint(expr=m.x[1] + m.x[2] == 1)
+
+        msg = "Got 2 variables and 1 constraints"
+        with self.assertRaisesRegex(RuntimeError, msg):
+            list(
+                generate_strongly_connected_components(
+                    constraints=[m.eq], variables=[m.x[1], m.x[2]]
+                )
+            )
+
+
 if __name__ == "__main__":
     unittest.main()
diff --git a/pyomo/contrib/incidence_analysis/tests/test_triangularize.py b/pyomo/contrib/incidence_analysis/tests/test_triangularize.py
index 76ba4403310..22548a15998 100644
--- a/pyomo/contrib/incidence_analysis/tests/test_triangularize.py
+++ b/pyomo/contrib/incidence_analysis/tests/test_triangularize.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/incidence_analysis/tests/test_visualize.py b/pyomo/contrib/incidence_analysis/tests/test_visualize.py
new file mode 100644
index 00000000000..7c5538b671f
--- /dev/null
+++ b/pyomo/contrib/incidence_analysis/tests/test_visualize.py
@@ -0,0 +1,47 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import pyomo.common.unittest as unittest
+from pyomo.common.dependencies import (
+    matplotlib,
+    matplotlib_available,
+    scipy_available,
+    networkx_available,
+)
+from pyomo.contrib.incidence_analysis.visualize import spy_dulmage_mendelsohn
+from pyomo.contrib.incidence_analysis.tests.models_for_testing import (
+    make_gas_expansion_model,
+    make_dynamic_model,
+    make_degenerate_solid_phase_model,
+)
+
+
+@unittest.skipUnless(matplotlib_available, "Matplotlib is not available")
+@unittest.skipUnless(scipy_available, "SciPy is not available")
+@unittest.skipUnless(networkx_available, "NetworkX is not available")
+class TestSpy(unittest.TestCase):
+    def test_spy_dulmage_mendelsohn(self):
+        models = [
+            make_gas_expansion_model(),
+            make_dynamic_model(),
+            make_degenerate_solid_phase_model(),
+        ]
+        for m in models:
+            fig, ax = spy_dulmage_mendelsohn(m)
+            # Note that this is a weak test. We just test that we can call the
+            # plot method, it doesn't raise an error, and gives us back the
+            # types we expect. We don't attempt to validate the resulting plot.
+            self.assertTrue(isinstance(fig, matplotlib.pyplot.Figure))
+            self.assertTrue(isinstance(ax, matplotlib.pyplot.Axes))
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/pyomo/contrib/incidence_analysis/triangularize.py b/pyomo/contrib/incidence_analysis/triangularize.py
index ac6680a367e..6af251b1ec6 100644
--- a/pyomo/contrib/incidence_analysis/triangularize.py
+++ b/pyomo/contrib/incidence_analysis/triangularize.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/incidence_analysis/util.py b/pyomo/contrib/incidence_analysis/util.py
index a127161d33d..8b6572eb900 100644
--- a/pyomo/contrib/incidence_analysis/util.py
+++ b/pyomo/contrib/incidence_analysis/util.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/incidence_analysis/visualize.py b/pyomo/contrib/incidence_analysis/visualize.py
new file mode 100644
index 00000000000..af1bdbbb918
--- /dev/null
+++ b/pyomo/contrib/incidence_analysis/visualize.py
@@ -0,0 +1,219 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+"""Module for visualizing results of incidence graph or matrix analysis
+
+"""
+from pyomo.contrib.incidence_analysis.config import IncidenceOrder
+from pyomo.contrib.incidence_analysis.interface import (
+    IncidenceGraphInterface,
+    get_structural_incidence_matrix,
+)
+from pyomo.common.dependencies import matplotlib
+
+
+def _partition_variables_and_constraints(
+    model, order=IncidenceOrder.dulmage_mendelsohn_upper, **kwds
+):
+    """Partition variables and constraints in an incidence graph"""
+    igraph = IncidenceGraphInterface(model, **kwds)
+    vdmp, cdmp = igraph.dulmage_mendelsohn()
+
+    ucv = vdmp.unmatched + vdmp.underconstrained
+    ucc = cdmp.underconstrained
+
+    ocv = vdmp.overconstrained
+    occ = cdmp.overconstrained + cdmp.unmatched
+
+    ucvblocks, uccblocks = igraph.get_connected_components(
+        variables=ucv, constraints=ucc
+    )
+    ocvblocks, occblocks = igraph.get_connected_components(
+        variables=ocv, constraints=occ
+    )
+    wcvblocks, wccblocks = igraph.block_triangularize(
+        variables=vdmp.square, constraints=cdmp.square
+    )
+    # By default, we block-*lower* triangularize. By default, however, we want
+    # the Dulmage-Mendelsohn decomposition to be block-*upper* triangular.
+    wcvblocks.reverse()
+    wccblocks.reverse()
+    vpartition = [ucvblocks, wcvblocks, ocvblocks]
+    cpartition = [uccblocks, wccblocks, occblocks]
+
+    if order == IncidenceOrder.dulmage_mendelsohn_lower:
+        # If a block-lower triangular matrix was requested, we need to reverse
+        # both the inner and outer partitions
+        vpartition.reverse()
+        cpartition.reverse()
+        for vb in vpartition:
+            vb.reverse()
+        for cb in cpartition:
+            cb.reverse()
+
+    return vpartition, cpartition
+
+
+def _get_rectangle_around_coords(ij1, ij2, linewidth=2, linestyle="-"):
+    i1, j1 = ij1
+    i2, j2 = ij2
+    buffer = 0.5
+    ll_corner = (min(i1, i2) - buffer, min(j1, j2) - buffer)
+    width = abs(i1 - i2) + 2 * buffer
+    height = abs(j1 - j2) + 2 * buffer
+    rect = matplotlib.patches.Rectangle(
+        ll_corner,
+        width,
+        height,
+        clip_on=False,
+        fill=False,
+        edgecolor="orange",
+        linewidth=linewidth,
+        linestyle=linestyle,
+    )
+    return rect
+
+
+def spy_dulmage_mendelsohn(
+    model,
+    *,
+    incidence_kwds=None,
+    order=IncidenceOrder.dulmage_mendelsohn_upper,
+    highlight_coarse=True,
+    highlight_fine=True,
+    skip_wellconstrained=False,
+    ax=None,
+    linewidth=2,
+    spy_kwds=None,
+):
+    """Plot sparsity structure in Dulmage-Mendelsohn order on Matplotlib axes
+
+    This is a wrapper around the Matplotlib ``Axes.spy`` method for plotting
+    an incidence matrix in Dulmage-Mendelsohn order, with coarse and/or fine
+    partitions highlighted. The coarse partition refers to the under-constrained,
+    over-constrained, and well-constrained subsystems, while the fine partition
+    refers to block diagonal or block triangular partitions of the former
+    subsystems.
+
+    Parameters
+    ----------
+
+    model: ``ConcreteModel``
+        Input model to plot sparsity structure of
+
+    incidence_kwds: dict, optional
+        Config options for ``IncidenceGraphInterface``
+
+    order: ``IncidenceOrder``, optional
+        Order in which to plot sparsity structure. Default is
+        ``IncidenceOrder.dulmage_mendelsohn_upper`` for a block-upper triangular
+        matrix. Set to ``IncidenceOrder.dulmage_mendelsohn_lower`` for a
+        block-lower triangular matrix.
+
+    highlight_coarse: bool, optional
+        Whether to draw a rectangle around the coarse partition. Default True
+
+    highlight_fine: bool, optional
+        Whether to draw a rectangle around the fine partition. Default True
+
+    skip_wellconstrained: bool, optional
+        Whether to skip highlighting the well-constrained subsystem of the
+        coarse partition. Default False
+
+    ax: ``matplotlib.pyplot.Axes``, optional
+        Axes object on which to plot. If not provided, new figure
+        and axes are created.
+
+    linewidth: int, optional
+        Line width of for rectangle used to highlight. Default 2
+
+    spy_kwds: dict, optional
+        Keyword arguments for ``Axes.spy``
+
+    Returns
+    -------
+
+    fig: ``matplotlib.pyplot.Figure`` or ``None``
+        Figure on which the sparsity structure is plotted. ``None`` if axes
+        are provided
+
+    ax: ``matplotlib.pyplot.Axes``
+        Axes on which the sparsity structure is plotted
+
+    """
+    plt = matplotlib.pyplot
+    if incidence_kwds is None:
+        incidence_kwds = {}
+    if spy_kwds is None:
+        spy_kwds = {}
+
+    vpart, cpart = _partition_variables_and_constraints(model, order=order)
+    vpart_fine = sum(vpart, [])
+    cpart_fine = sum(cpart, [])
+    vorder = sum(vpart_fine, [])
+    corder = sum(cpart_fine, [])
+
+    imat = get_structural_incidence_matrix(vorder, corder)
+    nvar = len(vorder)
+    ncon = len(corder)
+
+    if ax is None:
+        fig, ax = plt.subplots()
+    else:
+        fig = None
+
+    markersize = spy_kwds.pop("markersize", None)
+    if markersize is None:
+        # At 10000 vars/cons, we want markersize=0.2
+        # At 20 vars/cons, we want markersize=10
+        # We assume we want a linear relationship between 1/nvar
+        # and the markersize.
+        markersize = (10.0 - 0.2) / (1 / 20 - 1 / 10000) * (
+            1 / max(nvar, ncon) - 1 / 10000
+        ) + 0.2
+
+    ax.spy(imat, markersize=markersize, **spy_kwds)
+    ax.tick_params(length=0)
+    if highlight_coarse:
+        start = (0, 0)
+        for i, (vblocks, cblocks) in enumerate(zip(vpart, cpart)):
+            # Get the total number of variables/constraints in this part
+            # of the coarse partition
+            nv = sum(len(vb) for vb in vblocks)
+            nc = sum(len(cb) for cb in cblocks)
+            stop = (start[0] + nv - 1, start[1] + nc - 1)
+            if not (i == 1 and skip_wellconstrained) and nv > 0 and nc > 0:
+                # Regardless of whether we are plotting in upper or lower
+                # triangular order, the well-constrained subsystem is at
+                # position 1
+                #
+                # The get-rectangle function doesn't look good if we give it
+                # an "empty region" to box.
+                ax.add_patch(
+                    _get_rectangle_around_coords(start, stop, linewidth=linewidth)
+                )
+            start = (stop[0] + 1, stop[1] + 1)
+
+    if highlight_fine:
+        # Use dashed lines to distinguish inner from outer partitions
+        # if we are highlighting both
+        linestyle = "--" if highlight_coarse else "-"
+        start = (0, 0)
+        for vb, cb in zip(vpart_fine, cpart_fine):
+            stop = (start[0] + len(vb) - 1, start[1] + len(cb) - 1)
+            # Note that the subset's we're boxing here can't be empty.
+            ax.add_patch(
+                _get_rectangle_around_coords(
+                    start, stop, linestyle=linestyle, linewidth=linewidth
+                )
+            )
+            start = (stop[0] + 1, stop[1] + 1)
+
+    return fig, ax
diff --git a/pyomo/contrib/interior_point/__init__.py b/pyomo/contrib/interior_point/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/interior_point/__init__.py
+++ b/pyomo/contrib/interior_point/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/interior_point/examples/__init__.py b/pyomo/contrib/interior_point/examples/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/interior_point/examples/__init__.py
+++ b/pyomo/contrib/interior_point/examples/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/interior_point/examples/ex1.py b/pyomo/contrib/interior_point/examples/ex1.py
index d9931e1daa8..f6d8f14ac0a 100644
--- a/pyomo/contrib/interior_point/examples/ex1.py
+++ b/pyomo/contrib/interior_point/examples/ex1.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/interior_point/interface.py b/pyomo/contrib/interior_point/interface.py
index 7d04f578238..93b83f385ba 100644
--- a/pyomo/contrib/interior_point/interface.py
+++ b/pyomo/contrib/interior_point/interface.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/interior_point/interior_point.py b/pyomo/contrib/interior_point/interior_point.py
index 00d26ddef03..502de338fdc 100644
--- a/pyomo/contrib/interior_point/interior_point.py
+++ b/pyomo/contrib/interior_point/interior_point.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/interior_point/inverse_reduced_hessian.py b/pyomo/contrib/interior_point/inverse_reduced_hessian.py
index 6144a4afeb8..ac3c6a98463 100644
--- a/pyomo/contrib/interior_point/inverse_reduced_hessian.py
+++ b/pyomo/contrib/interior_point/inverse_reduced_hessian.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/interior_point/linalg/__init__.py b/pyomo/contrib/interior_point/linalg/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/interior_point/linalg/__init__.py
+++ b/pyomo/contrib/interior_point/linalg/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/interior_point/linalg/base_linear_solver_interface.py b/pyomo/contrib/interior_point/linalg/base_linear_solver_interface.py
index 722a5c55e8d..c3304fd1395 100644
--- a/pyomo/contrib/interior_point/linalg/base_linear_solver_interface.py
+++ b/pyomo/contrib/interior_point/linalg/base_linear_solver_interface.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.contrib.pynumero.linalg.base import DirectLinearSolverInterface
 from abc import ABCMeta, abstractmethod
 import logging
diff --git a/pyomo/contrib/interior_point/linalg/ma27_interface.py b/pyomo/contrib/interior_point/linalg/ma27_interface.py
index 7bb98b0b6fd..7604bd432bb 100644
--- a/pyomo/contrib/interior_point/linalg/ma27_interface.py
+++ b/pyomo/contrib/interior_point/linalg/ma27_interface.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from .base_linear_solver_interface import IPLinearSolverInterface
 from pyomo.contrib.pynumero.linalg.base import LinearSolverStatus, LinearSolverResults
 from pyomo.contrib.pynumero.linalg.ma27_interface import MA27
diff --git a/pyomo/contrib/interior_point/linalg/mumps_interface.py b/pyomo/contrib/interior_point/linalg/mumps_interface.py
index 98f0ef03210..c7480e2b6d0 100644
--- a/pyomo/contrib/interior_point/linalg/mumps_interface.py
+++ b/pyomo/contrib/interior_point/linalg/mumps_interface.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/interior_point/linalg/scipy_interface.py b/pyomo/contrib/interior_point/linalg/scipy_interface.py
index b7b7923bad4..d0f773fcb81 100644
--- a/pyomo/contrib/interior_point/linalg/scipy_interface.py
+++ b/pyomo/contrib/interior_point/linalg/scipy_interface.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from .base_linear_solver_interface import IPLinearSolverInterface
 from pyomo.contrib.pynumero.linalg.base import LinearSolverResults
 from scipy.linalg import eigvals
diff --git a/pyomo/contrib/interior_point/linalg/tests/__init__.py b/pyomo/contrib/interior_point/linalg/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/interior_point/linalg/tests/__init__.py
+++ b/pyomo/contrib/interior_point/linalg/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/interior_point/linalg/tests/test_linear_solvers.py b/pyomo/contrib/interior_point/linalg/tests/test_linear_solvers.py
index 35863aa7cf7..93071a5f215 100644
--- a/pyomo/contrib/interior_point/linalg/tests/test_linear_solvers.py
+++ b/pyomo/contrib/interior_point/linalg/tests/test_linear_solvers.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.common.unittest as unittest
 from pyomo.common.dependencies import attempt_import
 
diff --git a/pyomo/contrib/interior_point/linalg/tests/test_realloc.py b/pyomo/contrib/interior_point/linalg/tests/test_realloc.py
index bfe089dc602..3a53d0e7db9 100644
--- a/pyomo/contrib/interior_point/linalg/tests/test_realloc.py
+++ b/pyomo/contrib/interior_point/linalg/tests/test_realloc.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.common.unittest as unittest
 from pyomo.common.dependencies import attempt_import
 
diff --git a/pyomo/contrib/interior_point/tests/__init__.py b/pyomo/contrib/interior_point/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/interior_point/tests/__init__.py
+++ b/pyomo/contrib/interior_point/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/interior_point/tests/test_interior_point.py b/pyomo/contrib/interior_point/tests/test_interior_point.py
index bff80934d20..a05408abe1e 100644
--- a/pyomo/contrib/interior_point/tests/test_interior_point.py
+++ b/pyomo/contrib/interior_point/tests/test_interior_point.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/interior_point/tests/test_inverse_reduced_hessian.py b/pyomo/contrib/interior_point/tests/test_inverse_reduced_hessian.py
index 67657dfce47..61f5e90e3cf 100644
--- a/pyomo/contrib/interior_point/tests/test_inverse_reduced_hessian.py
+++ b/pyomo/contrib/interior_point/tests/test_inverse_reduced_hessian.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/interior_point/tests/test_realloc.py b/pyomo/contrib/interior_point/tests/test_realloc.py
index b3758c946d4..b7a5d00e488 100644
--- a/pyomo/contrib/interior_point/tests/test_realloc.py
+++ b/pyomo/contrib/interior_point/tests/test_realloc.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.common.unittest as unittest
 import pyomo.environ as pe
 from pyomo.core.base import ConcreteModel, Var, Constraint, Objective
diff --git a/pyomo/contrib/interior_point/tests/test_reg.py b/pyomo/contrib/interior_point/tests/test_reg.py
index b37d9532428..a7fc686545b 100644
--- a/pyomo/contrib/interior_point/tests/test_reg.py
+++ b/pyomo/contrib/interior_point/tests/test_reg.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/latex_printer/__init__.py b/pyomo/contrib/latex_printer/__init__.py
index 27c1552017a..02eaa636a36 100644
--- a/pyomo/contrib/latex_printer/__init__.py
+++ b/pyomo/contrib/latex_printer/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2023
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -13,7 +13,7 @@
 import pyomo.environ
 
 # Remove one layer of .latex_printer
-# import statemnt is now:
+# import statement is now:
 #   from pyomo.contrib.latex_printer import latex_printer
 try:
     from pyomo.contrib.latex_printer.latex_printer import latex_printer
diff --git a/pyomo/contrib/latex_printer/latex_printer.py b/pyomo/contrib/latex_printer/latex_printer.py
index b84f9a420fc..cf286472a66 100644
--- a/pyomo/contrib/latex_printer/latex_printer.py
+++ b/pyomo/contrib/latex_printer/latex_printer.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2023
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -34,8 +34,8 @@
 
 from pyomo.core.expr.visitor import identify_components
 from pyomo.core.expr.base import ExpressionBase
-from pyomo.core.base.expression import ScalarExpression, _GeneralExpressionData
-from pyomo.core.base.objective import ScalarObjective, _GeneralObjectiveData
+from pyomo.core.base.expression import ScalarExpression, ExpressionData
+from pyomo.core.base.objective import ScalarObjective, ObjectiveData
 import pyomo.core.kernel as kernel
 from pyomo.core.expr.template_expr import (
     GetItemExpression,
@@ -47,9 +47,9 @@
     resolve_template,
     templatize_rule,
 )
-from pyomo.core.base.var import ScalarVar, _GeneralVarData, IndexedVar
-from pyomo.core.base.param import _ParamData, ScalarParam, IndexedParam
-from pyomo.core.base.set import _SetData
+from pyomo.core.base.var import ScalarVar, VarData, IndexedVar
+from pyomo.core.base.param import ParamData, ScalarParam, IndexedParam
+from pyomo.core.base.set import SetData, SetOperator
 from pyomo.core.base.constraint import ScalarConstraint, IndexedConstraint
 from pyomo.common.collections.component_map import ComponentMap
 from pyomo.common.collections.component_set import ComponentSet
@@ -64,7 +64,7 @@
 from pyomo.core.base.external import _PythonCallbackFunctionID
 from pyomo.core.base.enums import SortComponents
 
-from pyomo.core.base.block import _BlockData
+from pyomo.core.base.block import BlockData
 
 from pyomo.repn.util import ExprType
 
@@ -79,6 +79,40 @@
 from pyomo.common.dependencies import numpy as np, numpy_available
 
 
+set_operator_map = {
+    '|': r' \cup ',
+    '&': r' \cap ',
+    '*': r' \times ',
+    '-': r' \setminus ',
+    '^': r' \triangle ',
+}
+
+latex_reals = r'\mathds{R}'
+latex_integers = r'\mathds{Z}'
+
+domainMap = {
+    'Reals': latex_reals,
+    'PositiveReals': latex_reals + '_{> 0}',
+    'NonPositiveReals': latex_reals + '_{\\leq 0}',
+    'NegativeReals': latex_reals + '_{< 0}',
+    'NonNegativeReals': latex_reals + '_{\\geq 0}',
+    'Integers': latex_integers,
+    'PositiveIntegers': latex_integers + '_{> 0}',
+    'NonPositiveIntegers': latex_integers + '_{\\leq 0}',
+    'NegativeIntegers': latex_integers + '_{< 0}',
+    'NonNegativeIntegers': latex_integers + '_{\\geq 0}',
+    'Boolean': '\\left\\{ \\text{True} , \\text{False} \\right \\}',
+    'Binary': '\\left\\{ 0 , 1 \\right \\}',
+    # 'Any': None,
+    # 'AnyWithNone': None,
+    'EmptySet': '\\varnothing',
+    'UnitInterval': latex_reals,
+    'PercentFraction': latex_reals,
+    # 'RealInterval' :        None    ,
+    # 'IntegerInterval' :     None    ,
+}
+
+
 def decoder(num, base):
     if int(num) != abs(num):
         # Requiring an integer is nice, but not strictly necessary;
@@ -275,14 +309,15 @@ def handle_functionID_node(visitor, node, *args):
 
 
 def handle_indexTemplate_node(visitor, node, *args):
-    if node._set in ComponentSet(visitor.setMap.keys()):
+    if node._set in visitor.setMap:
         # already detected set, do nothing
         pass
     else:
-        visitor.setMap[node._set] = 'SET%d' % (len(visitor.setMap.keys()) + 1)
+        visitor.setMap[node._set] = 'SET%d' % (len(visitor.setMap) + 1)
 
-    return '__I_PLACEHOLDER_8675309_GROUP_%s_%s__' % (
+    return '__I_PLACEHOLDER_8675309_GROUP_%s_%s_%s__' % (
         node._group,
+        node._id,
         visitor.setMap[node._set],
     )
 
@@ -304,8 +339,9 @@ def handle_numericGetItemExpression_node(visitor, node, *args):
 def handle_templateSumExpression_node(visitor, node, *args):
     pstr = ''
     for i in range(0, len(node._iters)):
-        pstr += '\\sum_{__S_PLACEHOLDER_8675309_GROUP_%s_%s__} ' % (
+        pstr += '\\sum_{__S_PLACEHOLDER_8675309_GROUP_%s_%s_%s__} ' % (
             node._iters[i][0]._group,
+            ','.join(str(it._id) for it in node._iters[i]),
             visitor.setMap[node._iters[i][0]._set],
         )
 
@@ -363,12 +399,12 @@ def __init__(self):
             EqualityExpression: handle_equality_node,
             InequalityExpression: handle_inequality_node,
             RangedExpression: handle_ranged_inequality_node,
-            _GeneralExpressionData: handle_named_expression_node,
+            ExpressionData: handle_named_expression_node,
             ScalarExpression: handle_named_expression_node,
             kernel.expression.expression: handle_named_expression_node,
             kernel.expression.noclone: handle_named_expression_node,
-            _GeneralObjectiveData: handle_named_expression_node,
-            _GeneralVarData: handle_var_node,
+            ObjectiveData: handle_named_expression_node,
+            VarData: handle_var_node,
             ScalarObjective: handle_named_expression_node,
             kernel.objective.objective: handle_named_expression_node,
             ExternalFunctionExpression: handle_external_function_node,
@@ -381,7 +417,7 @@ def __init__(self):
             Numeric_GetItemExpression: handle_numericGetItemExpression_node,
             TemplateSumExpression: handle_templateSumExpression_node,
             ScalarParam: handle_param_node,
-            _ParamData: handle_param_node,
+            ParamData: handle_param_node,
             IndexedParam: handle_param_node,
             NPV_Numeric_GetItemExpression: handle_numericGetItemExpression_node,
             IndexedBlock: handle_indexedBlock_node,
@@ -405,28 +441,6 @@ def exitNode(self, node, data):
 
 
 def analyze_variable(vr):
-    domainMap = {
-        'Reals': '\\mathds{R}',
-        'PositiveReals': '\\mathds{R}_{> 0}',
-        'NonPositiveReals': '\\mathds{R}_{\\leq 0}',
-        'NegativeReals': '\\mathds{R}_{< 0}',
-        'NonNegativeReals': '\\mathds{R}_{\\geq 0}',
-        'Integers': '\\mathds{Z}',
-        'PositiveIntegers': '\\mathds{Z}_{> 0}',
-        'NonPositiveIntegers': '\\mathds{Z}_{\\leq 0}',
-        'NegativeIntegers': '\\mathds{Z}_{< 0}',
-        'NonNegativeIntegers': '\\mathds{Z}_{\\geq 0}',
-        'Boolean': '\\left\\{ \\text{True} , \\text{False} \\right \\}',
-        'Binary': '\\left\\{ 0 , 1 \\right \\}',
-        # 'Any': None,
-        # 'AnyWithNone': None,
-        'EmptySet': '\\varnothing',
-        'UnitInterval': '\\mathds{R}',
-        'PercentFraction': '\\mathds{R}',
-        # 'RealInterval' :        None    ,
-        # 'IntegerInterval' :     None    ,
-    }
-
     domainName = vr.domain.name
     varBounds = vr.bounds
     lowerBoundValue = varBounds[0]
@@ -573,7 +587,7 @@ def latex_printer(
 
     Parameters
     ----------
-    pyomo_component: _BlockData or Model or Objective or Constraint or Expression
+    pyomo_component: BlockData or Model or Objective or Constraint or Expression
         The Pyomo component to be printed
 
     latex_component_map: pyomo.common.collections.component_map.ComponentMap
@@ -616,15 +630,15 @@ def latex_printer(
 
     # Cody's backdoor because he got outvoted
     if latex_component_map is not None:
-        if 'use_short_descriptors' in list(latex_component_map.keys()):
+        if 'use_short_descriptors' in latex_component_map:
             if latex_component_map['use_short_descriptors'] == False:
                 use_short_descriptors = False
 
     if latex_component_map is None:
         latex_component_map = ComponentMap()
-        existing_components = ComponentSet([])
+        existing_components = ComponentSet()
     else:
-        existing_components = ComponentSet(list(latex_component_map.keys()))
+        existing_components = ComponentSet(latex_component_map)
 
     isSingle = False
 
@@ -660,7 +674,7 @@ def latex_printer(
         use_equation_environment = True
         isSingle = True
 
-    elif isinstance(pyomo_component, _BlockData):
+    elif isinstance(pyomo_component, BlockData):
         objectives = [
             obj
             for obj in pyomo_component.component_data_objects(
@@ -691,10 +705,8 @@ def latex_printer(
     if isSingle:
         temp_comp, temp_indexes = templatize_fcn(pyomo_component)
         variableList = []
-        for v in identify_components(
-            temp_comp, [ScalarVar, _GeneralVarData, IndexedVar]
-        ):
-            if isinstance(v, _GeneralVarData):
+        for v in identify_components(temp_comp, [ScalarVar, VarData, IndexedVar]):
+            if isinstance(v, VarData):
                 v_write = v.parent_component()
                 if v_write not in ComponentSet(variableList):
                     variableList.append(v_write)
@@ -703,10 +715,8 @@ def latex_printer(
                     variableList.append(v)
 
         parameterList = []
-        for p in identify_components(
-            temp_comp, [ScalarParam, _ParamData, IndexedParam]
-        ):
-            if isinstance(p, _ParamData):
+        for p in identify_components(temp_comp, [ScalarParam, ParamData, IndexedParam]):
+            if isinstance(p, ParamData):
                 p_write = p.parent_component()
                 if p_write not in ComponentSet(parameterList):
                     parameterList.append(p_write)
@@ -771,12 +781,12 @@ def latex_printer(
     for vr in variableList:
         vrIdx += 1
         if isinstance(vr, ScalarVar):
-            variableMap[vr] = 'x_' + str(vrIdx)
+            variableMap[vr] = 'x_' + str(vrIdx) + '_'
         elif isinstance(vr, IndexedVar):
-            variableMap[vr] = 'x_' + str(vrIdx)
+            variableMap[vr] = 'x_' + str(vrIdx) + '_'
             for sd in vr.index_set().data():
                 vrIdx += 1
-                variableMap[vr[sd]] = 'x_' + str(vrIdx)
+                variableMap[vr[sd]] = 'x_' + str(vrIdx) + '_'
         else:
             raise DeveloperError(
                 'Variable is not a variable.  Should not happen.  Contact developers'
@@ -788,12 +798,12 @@ def latex_printer(
     for vr in parameterList:
         pmIdx += 1
         if isinstance(vr, ScalarParam):
-            parameterMap[vr] = 'p_' + str(pmIdx)
+            parameterMap[vr] = 'p_' + str(pmIdx) + '_'
         elif isinstance(vr, IndexedParam):
-            parameterMap[vr] = 'p_' + str(pmIdx)
+            parameterMap[vr] = 'p_' + str(pmIdx) + '_'
             for sd in vr.index_set().data():
                 pmIdx += 1
-                parameterMap[vr[sd]] = 'p_' + str(pmIdx)
+                parameterMap[vr[sd]] = 'p_' + str(pmIdx) + '_'
         else:
             raise DeveloperError(
                 'Parameter is not a parameter.  Should not happen.  Contact developers'
@@ -904,24 +914,33 @@ def latex_printer(
                 # setMap = visitor.setMap
                 # Multiple constraints are generated using a set
                 if len(indices) > 0:
-                    if indices[0]._set in ComponentSet(visitor.setMap.keys()):
-                        # already detected set, do nothing
-                        pass
-                    else:
-                        visitor.setMap[indices[0]._set] = 'SET%d' % (
-                            len(visitor.setMap.keys()) + 1
+                    conLine += ' \\qquad \\forall'
+
+                    _bygroups = {}
+                    for idx in indices:
+                        _bygroups.setdefault(idx._group, []).append(idx)
+                    for _group, idxs in _bygroups.items():
+                        if idxs[0]._set in visitor.setMap:
+                            # already detected set, do nothing
+                            pass
+                        else:
+                            visitor.setMap[idxs[0]._set] = 'SET%d' % (
+                                len(visitor.setMap) + 1
+                            )
+
+                        idxTag = ','.join(
+                            '__I_PLACEHOLDER_8675309_GROUP_%s_%s_%s__'
+                            % (idx._group, idx._id, visitor.setMap[idx._set])
+                            for idx in idxs
                         )
 
-                    idxTag = '__I_PLACEHOLDER_8675309_GROUP_%s_%s__' % (
-                        indices[0]._group,
-                        visitor.setMap[indices[0]._set],
-                    )
-                    setTag = '__S_PLACEHOLDER_8675309_GROUP_%s_%s__' % (
-                        indices[0]._group,
-                        visitor.setMap[indices[0]._set],
-                    )
+                        setTag = '__S_PLACEHOLDER_8675309_GROUP_%s_%s_%s__' % (
+                            indices[0]._group,
+                            ','.join(str(it._id) for it in idxs),
+                            visitor.setMap[indices[0]._set],
+                        )
 
-                    conLine += ' \\qquad \\forall %s \\in %s ' % (idxTag, setTag)
+                        conLine += ' %s \\in %s ' % (idxTag, setTag)
                 pstr += conLine
 
                 # Add labels as needed
@@ -1048,15 +1067,22 @@ def latex_printer(
     setMap = visitor.setMap
     setMap_inverse = {vl: ky for ky, vl in setMap.items()}
 
+    def generate_set_name(st, lcm):
+        if st in lcm:
+            return lcm[st][0]
+        if st.parent_block().component(st.name) is st:
+            return st.name.replace('_', r'\_')
+        if isinstance(st, SetOperator):
+            return set_operator_map[st._operator.strip()].join(
+                generate_set_name(s, lcm) for s in st.subsets(False)
+            )
+        else:
+            return str(st).replace('_', r'\_').replace('{', r'\{').replace('}', r'\}')
+
     # Handling the iterator indices
     defaultSetLatexNames = ComponentMap()
-    for ky, vl in setMap.items():
-        st = ky
-        defaultSetLatexNames[st] = st.name.replace('_', '\\_')
-        if st in ComponentSet(latex_component_map.keys()):
-            defaultSetLatexNames[st] = latex_component_map[st][
-                0
-            ]  # .replace('_', '\\_')
+    for ky in setMap:
+        defaultSetLatexNames[ky] = generate_set_name(ky, latex_component_map)
 
     latexLines = pstr.split('\n')
     for jj in range(0, len(latexLines)):
@@ -1070,8 +1096,8 @@ def latex_printer(
             for word in splitLatex:
                 if "PLACEHOLDER_8675309_GROUP_" in word:
                     ifo = word.split("PLACEHOLDER_8675309_GROUP_")[1]
-                    gpNum, stName = ifo.split('_')
-                    if gpNum not in groupMap.keys():
+                    gpNum, idNum, stName = ifo.split('_')
+                    if gpNum not in groupMap:
                         groupMap[gpNum] = [stName]
                     if stName not in ComponentSet(uniqueSets):
                         uniqueSets.append(stName)
@@ -1088,10 +1114,7 @@ def latex_printer(
                 ix = int(ky[3:]) - 1
                 setInfo[ky]['setObject'] = setMap_inverse[ky]  # setList[ix]
                 setInfo[ky]['setRegEx'] = (
-                    r'__S_PLACEHOLDER_8675309_GROUP_([0-9*])_%s__' % (ky)
-                )
-                setInfo[ky]['sumSetRegEx'] = (
-                    r'sum_{__S_PLACEHOLDER_8675309_GROUP_([0-9*])_%s__}' % (ky)
+                    r'__S_PLACEHOLDER_8675309_GROUP_([0-9]+)_([0-9,]+)_%s__' % (ky,)
                 )
                 # setInfo[ky]['idxRegEx'] = r'__I_PLACEHOLDER_8675309_GROUP_[0-9*]_%s__'%(ky)
 
@@ -1116,27 +1139,41 @@ def latex_printer(
                     ed = stData[-1]
 
                     replacement = (
-                        r'sum_{ __I_PLACEHOLDER_8675309_GROUP_\1_%s__ = %d }^{%d}'
+                        r'sum_{ __I_PLACEHOLDER_8675309_GROUP_\1_\2_%s__ = %d }^{%d}'
                         % (ky, bgn, ed)
                     )
-                    ln = re.sub(setInfo[ky]['sumSetRegEx'], replacement, ln)
+                    ln = re.sub(
+                        'sum_{' + setInfo[ky]['setRegEx'] + '}', replacement, ln
+                    )
                 else:
                     # if the set is not continuous or the flag has not been set
-                    replacement = (
-                        r'sum_{ __I_PLACEHOLDER_8675309_GROUP_\1_%s__ \\in __S_PLACEHOLDER_8675309_GROUP_\1_%s__  }'
-                        % (ky, ky)
-                    )
-                    ln = re.sub(setInfo[ky]['sumSetRegEx'], replacement, ln)
+                    for _grp, _id in re.findall(
+                        'sum_{' + setInfo[ky]['setRegEx'] + '}', ln
+                    ):
+                        set_placeholder = '__S_PLACEHOLDER_8675309_GROUP_%s_%s_%s__' % (
+                            _grp,
+                            _id,
+                            ky,
+                        )
+                        i_placeholder = ','.join(
+                            '__I_PLACEHOLDER_8675309_GROUP_%s_%s_%s__' % (_grp, _, ky)
+                            for _ in _id.split(',')
+                        )
+                        replacement = r'sum_{ %s \in %s  }' % (
+                            i_placeholder,
+                            set_placeholder,
+                        )
+                        ln = ln.replace('sum_{' + set_placeholder + '}', replacement)
 
                 replacement = repr(defaultSetLatexNames[setInfo[ky]['setObject']])[1:-1]
                 ln = re.sub(setInfo[ky]['setRegEx'], replacement, ln)
 
             # groupNumbers = re.findall(r'__I_PLACEHOLDER_8675309_GROUP_([0-9*])_SET[0-9]*__',ln)
             setNumbers = re.findall(
-                r'__I_PLACEHOLDER_8675309_GROUP_[0-9*]_SET([0-9]*)__', ln
+                r'__I_PLACEHOLDER_8675309_GROUP_[0-9]+_[0-9]+_SET([0-9]+)__', ln
             )
-            groupSetPairs = re.findall(
-                r'__I_PLACEHOLDER_8675309_GROUP_([0-9*])_SET([0-9]*)__', ln
+            groupIdSetTuples = re.findall(
+                r'__I_PLACEHOLDER_8675309_GROUP_([0-9]+)_([0-9]+)_SET([0-9]+)__', ln
             )
 
             groupInfo = {}
@@ -1146,43 +1183,44 @@ def latex_printer(
                     'indices': [],
                 }
 
-            for gp in groupSetPairs:
-                if gp[0] not in groupInfo['SET' + gp[1]]['indices']:
-                    groupInfo['SET' + gp[1]]['indices'].append(gp[0])
+            for _gp, _id, _set in groupIdSetTuples:
+                if (_gp, _id) not in groupInfo['SET' + _set]['indices']:
+                    groupInfo['SET' + _set]['indices'].append((_gp, _id))
+
+            def get_index_names(st, lcm):
+                if st in lcm:
+                    return lcm[st][1]
+                elif isinstance(st, SetOperator):
+                    return sum(
+                        (get_index_names(s, lcm) for s in st.subsets(False)), start=[]
+                    )
+                elif st.dimen is not None:
+                    return [None] * st.dimen
+                else:
+                    return [Ellipsis]
 
             indexCounter = 0
             for ky, vl in groupInfo.items():
-                if vl['setObject'] in ComponentSet(latex_component_map.keys()):
-                    indexNames = latex_component_map[vl['setObject']][1]
-                    if len(indexNames) != 0:
-                        if len(indexNames) < len(vl['indices']):
-                            raise ValueError(
-                                'Insufficient number of indices provided to the overwrite dictionary for set %s'
-                                % (vl['setObject'].name)
-                            )
-                        for i in range(0, len(vl['indices'])):
-                            ln = ln.replace(
-                                '__I_PLACEHOLDER_8675309_GROUP_%s_%s__'
-                                % (vl['indices'][i], ky),
-                                indexNames[i],
-                            )
-                    else:
-                        for i in range(0, len(vl['indices'])):
-                            ln = ln.replace(
-                                '__I_PLACEHOLDER_8675309_GROUP_%s_%s__'
-                                % (vl['indices'][i], ky),
-                                alphabetStringGenerator(indexCounter),
-                            )
-                            indexCounter += 1
-                else:
-                    for i in range(0, len(vl['indices'])):
-                        ln = ln.replace(
-                            '__I_PLACEHOLDER_8675309_GROUP_%s_%s__'
-                            % (vl['indices'][i], ky),
-                            alphabetStringGenerator(indexCounter),
+                indexNames = get_index_names(vl['setObject'], latex_component_map)
+                nonNone = list(filter(None, indexNames))
+                if nonNone:
+                    if len(nonNone) < len(vl['indices']):
+                        raise ValueError(
+                            'Insufficient number of indices provided to the '
+                            'overwrite dictionary for set %s (expected %s, but got %s)'
+                            % (vl['setObject'].name, len(vl['indices']), indexNames)
                         )
+                else:
+                    indexNames = []
+                    for i in vl['indices']:
+                        indexNames.append(alphabetStringGenerator(indexCounter))
                         indexCounter += 1
-
+                for i in range(0, len(vl['indices'])):
+                    ln = ln.replace(
+                        '__I_PLACEHOLDER_8675309_GROUP_%s_%s_%s__'
+                        % (*vl['indices'][i], ky),
+                        indexNames[i],
+                    )
         latexLines[jj] = ln
 
     pstr = '\n'.join(latexLines)
@@ -1225,25 +1263,25 @@ def latex_printer(
             )
 
     for ky, vl in new_variableMap.items():
-        if ky not in ComponentSet(latex_component_map.keys()):
+        if ky not in latex_component_map:
             latex_component_map[ky] = vl
     for ky, vl in new_parameterMap.items():
-        if ky not in ComponentSet(latex_component_map.keys()):
+        if ky not in latex_component_map:
             latex_component_map[ky] = vl
 
     rep_dict = {}
-    for ky in ComponentSet(list(reversed(list(latex_component_map.keys())))):
-        if isinstance(ky, (pyo.Var, _GeneralVarData)):
+    for ky in reversed(list(latex_component_map)):
+        if isinstance(ky, (pyo.Var, VarData)):
             overwrite_value = latex_component_map[ky]
             if ky not in existing_components:
                 overwrite_value = overwrite_value.replace('_', '\\_')
             rep_dict[variableMap[ky]] = overwrite_value
-        elif isinstance(ky, (pyo.Param, _ParamData)):
+        elif isinstance(ky, (pyo.Param, ParamData)):
             overwrite_value = latex_component_map[ky]
             if ky not in existing_components:
                 overwrite_value = overwrite_value.replace('_', '\\_')
             rep_dict[parameterMap[ky]] = overwrite_value
-        elif isinstance(ky, _SetData):
+        elif isinstance(ky, SetData):
             # already handled
             pass
         elif isinstance(ky, (float, int)):
diff --git a/pyomo/contrib/latex_printer/tests/__init__.py b/pyomo/contrib/latex_printer/tests/__init__.py
index 8b137891791..a4a626013c4 100644
--- a/pyomo/contrib/latex_printer/tests/__init__.py
+++ b/pyomo/contrib/latex_printer/tests/__init__.py
@@ -1 +1,10 @@
-
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/latex_printer/tests/test_latex_printer.py b/pyomo/contrib/latex_printer/tests/test_latex_printer.py
index e9de4e4ad05..b0ada97a5fe 100644
--- a/pyomo/contrib/latex_printer/tests/test_latex_printer.py
+++ b/pyomo/contrib/latex_printer/tests/test_latex_printer.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2023
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -10,13 +10,15 @@
 #  ___________________________________________________________________________
 
 import io
+from textwrap import dedent
+
 import pyomo.common.unittest as unittest
-from pyomo.contrib.latex_printer import latex_printer
+import pyomo.core.tests.examples.pmedian_concrete as pmedian_concrete
 import pyomo.environ as pyo
-from textwrap import dedent
+
+from pyomo.contrib.latex_printer import latex_printer
 from pyomo.common.tempfiles import TempfileManager
 from pyomo.common.collections.component_map import ComponentMap
-
 from pyomo.environ import (
     Reals,
     PositiveReals,
@@ -786,6 +788,50 @@ def ruleMaker_2(m, i):
 
         self.assertEqual('\n' + pstr + '\n', bstr)
 
+    def test_latexPrinter_pmedian_verbose(self):
+        m = pmedian_concrete.create_model()
+        self.assertEqual(
+            latex_printer(m).strip(),
+            r"""
+\begin{align} 
+    & \min 
+    & & \sum_{ i \in Locations  } \sum_{ j \in Customers  } cost_{i,j} serve\_customer\_from\_location_{i,j} & \label{obj:M1_obj} \\ 
+    & \text{s.t.} 
+    & & \sum_{ i \in Locations  } serve\_customer\_from\_location_{i,j} = 1 &  \qquad \forall j \in Customers \label{con:M1_single_x} \\ 
+    &&& serve\_customer\_from\_location_{i,j} \leq select\_location_{i} &  \qquad \forall i,j \in Locations \times Customers \label{con:M1_bound_y} \\ 
+    &&& \sum_{ i \in Locations  } select\_location_{i} = P & \label{con:M1_num_facilities} \\ 
+    & \text{w.b.} 
+    & & 0.0 \leq serve\_customer\_from\_location \leq 1.0 & \qquad \in \mathds{R} \label{con:M1_serve_customer_from_location_bound} \\ 
+    &&& select\_location & \qquad \in \left\{ 0 , 1 \right \} \label{con:M1_select_location_bound} 
+\end{align}
+            """.strip(),
+        )
+
+    def test_latexPrinter_pmedian_concise(self):
+        m = pmedian_concrete.create_model()
+        lcm = ComponentMap()
+        lcm[m.Locations] = ['L', ['n']]
+        lcm[m.Customers] = ['C', ['m']]
+        lcm[m.cost] = 'd'
+        lcm[m.serve_customer_from_location] = 'x'
+        lcm[m.select_location] = 'y'
+        self.assertEqual(
+            latex_printer(m, latex_component_map=lcm).strip(),
+            r"""
+\begin{align} 
+    & \min 
+    & & \sum_{ n \in L  } \sum_{ m \in C  } d_{n,m} x_{n,m} & \label{obj:M1_obj} \\ 
+    & \text{s.t.} 
+    & & \sum_{ n \in L  } x_{n,m} = 1 &  \qquad \forall m \in C \label{con:M1_single_x} \\ 
+    &&& x_{n,m} \leq y_{n} &  \qquad \forall n,m \in L \times C \label{con:M1_bound_y} \\ 
+    &&& \sum_{ n \in L  } y_{n} = P & \label{con:M1_num_facilities} \\ 
+    & \text{w.b.} 
+    & & 0.0 \leq x \leq 1.0 & \qquad \in \mathds{R} \label{con:M1_x_bound} \\ 
+    &&& y & \qquad \in \left\{ 0 , 1 \right \} \label{con:M1_y_bound} 
+\end{align}
+            """.strip(),
+        )
+
 
 if __name__ == '__main__':
     unittest.main()
diff --git a/pyomo/contrib/latex_printer/tests/test_latex_printer_vartypes.py b/pyomo/contrib/latex_printer/tests/test_latex_printer_vartypes.py
index 14e9ebbe0e6..dc3a415618b 100644
--- a/pyomo/contrib/latex_printer/tests/test_latex_printer_vartypes.py
+++ b/pyomo/contrib/latex_printer/tests/test_latex_printer_vartypes.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
diff --git a/pyomo/contrib/mcpp/__init__.py b/pyomo/contrib/mcpp/__init__.py
index d93cfd77b3c..a4a626013c4 100644
--- a/pyomo/contrib/mcpp/__init__.py
+++ b/pyomo/contrib/mcpp/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mcpp/build.py b/pyomo/contrib/mcpp/build.py
index 55c893335d2..7e119caec9f 100644
--- a/pyomo/contrib/mcpp/build.py
+++ b/pyomo/contrib/mcpp/build.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mcpp/getMCPP.py b/pyomo/contrib/mcpp/getMCPP.py
index caf9566df64..dbce611d1a0 100644
--- a/pyomo/contrib/mcpp/getMCPP.py
+++ b/pyomo/contrib/mcpp/getMCPP.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mcpp/mcppInterface.cpp b/pyomo/contrib/mcpp/mcppInterface.cpp
index 30491fde1b1..a1e74567896 100644
--- a/pyomo/contrib/mcpp/mcppInterface.cpp
+++ b/pyomo/contrib/mcpp/mcppInterface.cpp
@@ -1,7 +1,7 @@
 /**___________________________________________________________________________
  *
  * Pyomo: Python Optimization Modeling Objects
- * Copyright (c) 2008-2022
+ * Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
  * Under the terms of Contract DE-NA0003525 with National Technology and
  * Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mcpp/plugins.py b/pyomo/contrib/mcpp/plugins.py
index eed8874b1e7..577feec7fe3 100644
--- a/pyomo/contrib/mcpp/plugins.py
+++ b/pyomo/contrib/mcpp/plugins.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mcpp/pyomo_mcpp.py b/pyomo/contrib/mcpp/pyomo_mcpp.py
index 25a4237ff16..0ef0237681b 100644
--- a/pyomo/contrib/mcpp/pyomo_mcpp.py
+++ b/pyomo/contrib/mcpp/pyomo_mcpp.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -20,7 +20,7 @@
 from pyomo.common.fileutils import Library
 from pyomo.core import value, Expression
 from pyomo.core.base.block import SubclassOf
-from pyomo.core.base.expression import _ExpressionData
+from pyomo.core.base.expression import NamedExpressionData
 from pyomo.core.expr.numvalue import nonpyomo_leaf_types
 from pyomo.core.expr.numeric_expr import (
     AbsExpression,
@@ -307,7 +307,9 @@ def exitNode(self, node, data):
             ans = self.mcpp.newConstant(node)
         elif not node.is_expression_type():
             ans = self.register_num(node)
-        elif type(node) in SubclassOf(Expression) or isinstance(node, _ExpressionData):
+        elif type(node) in SubclassOf(Expression) or isinstance(
+            node, NamedExpressionData
+        ):
             ans = data[0]
         else:
             raise RuntimeError("Unhandled expression type: %s" % (type(node)))
diff --git a/pyomo/contrib/mcpp/test_mcpp.py b/pyomo/contrib/mcpp/test_mcpp.py
index 23b963e11bf..1cfb46ce328 100644
--- a/pyomo/contrib/mcpp/test_mcpp.py
+++ b/pyomo/contrib/mcpp/test_mcpp.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mindtpy/MindtPy.py b/pyomo/contrib/mindtpy/MindtPy.py
index 6eb27c4c649..7b41e0078a3 100644
--- a/pyomo/contrib/mindtpy/MindtPy.py
+++ b/pyomo/contrib/mindtpy/MindtPy.py
@@ -3,7 +3,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -50,6 +50,14 @@
 - Add single-tree implementation.
 - Add support for cplex_persistent solver.
 - Fix bug in OA cut expression in cut_generation.py.
+
+24.1.11 changes:
+- fix gurobi single tree termination check bug
+- fix Gurobi single tree cycle handling
+- fix bug in feasibility pump method
+- add special handling for infeasible relaxed NLP
+- update the log format of infeasible fixed NLP subproblems
+- create a new copy_var_list_values function
 """
 
 from pyomo.contrib.mindtpy import __version__
diff --git a/pyomo/contrib/mindtpy/__init__.py b/pyomo/contrib/mindtpy/__init__.py
index 8e2c2d9eaa4..652493b03a6 100644
--- a/pyomo/contrib/mindtpy/__init__.py
+++ b/pyomo/contrib/mindtpy/__init__.py
@@ -1 +1,12 @@
-__version__ = (0, 1, 0)
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+__version__ = (1, 0, 0)
diff --git a/pyomo/contrib/mindtpy/algorithm_base_class.py b/pyomo/contrib/mindtpy/algorithm_base_class.py
index 570e7c0a27d..e015fc89e09 100644
--- a/pyomo/contrib/mindtpy/algorithm_base_class.py
+++ b/pyomo/contrib/mindtpy/algorithm_base_class.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -27,13 +27,7 @@
 from operator import itemgetter
 from pyomo.common.errors import DeveloperError
 from pyomo.solvers.plugins.solvers.gurobi_direct import gurobipy
-from pyomo.opt import (
-    SolverFactory,
-    SolverResults,
-    ProblemSense,
-    SolutionStatus,
-    SolverStatus,
-)
+from pyomo.opt import SolverFactory, SolverResults, SolutionStatus, SolverStatus
 from pyomo.core import (
     minimize,
     maximize,
@@ -55,7 +49,6 @@
     SuppressInfeasibleWarning,
     _DoNothing,
     lower_logger_level_to,
-    copy_var_list_values,
     get_main_elapsed_time,
     time_code,
 )
@@ -80,6 +73,7 @@
     set_solver_mipgap,
     set_solver_constraint_violation_tolerance,
     update_solver_timelimit,
+    copy_var_list_values,
 )
 
 single_tree, single_tree_available = attempt_import('pyomo.contrib.mindtpy.single_tree')
@@ -102,12 +96,14 @@ def __init__(self, **kwds):
         self.fixed_nlp = None
 
         # We store bounds, timing info, iteration count, incumbent, and the
-        # expression of the original (possibly nonlinear) objective function.
+        # Expression of the original (possibly nonlinear) objective function.
         self.results = SolverResults()
         self.timing = Bunch()
         self.curr_int_sol = []
         self.should_terminate = False
         self.integer_list = []
+        # Dictionary {integer solution (tuple): [cuts begin index, cuts end index] (list)}
+        self.integer_solution_to_cuts_index = dict()
 
         # Set up iteration counters
         self.nlp_iter = 0
@@ -123,9 +119,15 @@ def __init__(self, **kwds):
         self.log_formatter = (
             ' {:>9}   {:>15}   {:>15g}   {:>12g}   {:>12g}   {:>7.2%}   {:>7.2f}'
         )
+        self.termination_condition_log_formatter = (
+            ' {:>9}   {:>15}   {:>15}   {:>12g}   {:>12g}   {:>7.2%}   {:>7.2f}'
+        )
         self.fixed_nlp_log_formatter = (
             '{:1}{:>9}   {:>15}   {:>15g}   {:>12g}   {:>12g}   {:>7.2%}   {:>7.2f}'
         )
+        self.infeasible_fixed_nlp_log_formatter = (
+            '{:1}{:>9}   {:>15}   {:>15}   {:>12g}   {:>12g}   {:>7.2%}   {:>7.2f}'
+        )
         self.log_note_formatter = ' {:>9}   {:>15}   {:>15}'
 
         # Flag indicating whether the solution improved in the past
@@ -144,7 +146,9 @@ def __init__(self, **kwds):
         # Store the OA cuts generated in the mip_start_process.
         self.mip_start_lazy_oa_cuts = []
         # Whether to load solutions in solve() function
-        self.load_solutions = True
+        self.mip_load_solutions = True
+        self.nlp_load_solutions = True
+        self.regularization_mip_load_solutions = True
 
     # Support use as a context manager under current solver API
     def __enter__(self):
@@ -294,7 +298,7 @@ def model_is_valid(self):
                 results = self.mip_opt.solve(
                     self.original_model,
                     tee=config.mip_solver_tee,
-                    load_solutions=self.load_solutions,
+                    load_solutions=self.mip_load_solutions,
                     **config.mip_solver_args,
                 )
                 if len(results.solution) > 0:
@@ -511,9 +515,9 @@ def get_primal_integral(self):
         return primal_integral
 
     def get_integral_info(self):
-        '''
+        """
         Obtain primal integral, dual integral and primal dual gap integral.
-        '''
+        """
         self.primal_integral = self.get_primal_integral()
         self.dual_integral = self.get_dual_integral()
         self.primal_dual_gap_integral = self.primal_integral + self.dual_integral
@@ -625,9 +629,7 @@ def process_objective(self, update_var_con_list=True):
             raise ValueError('Model has multiple active objectives.')
         else:
             main_obj = active_objectives[0]
-        self.results.problem.sense = (
-            ProblemSense.minimize if main_obj.sense == 1 else ProblemSense.maximize
-        )
+        self.results.problem.sense = main_obj.sense
         self.objective_sense = main_obj.sense
 
         # Move the objective to the constraints if it is nonlinear or move_objective is True.
@@ -797,7 +799,7 @@ def MindtPy_initialization(self):
             try:
                 self.curr_int_sol = get_integer_solution(self.working_model)
             except TypeError as e:
-                config.logger.error(e)
+                config.logger.error(e, exc_info=True)
                 raise ValueError(
                     'The initial integer combination is not provided or not complete. '
                     'Please provide the complete integer combination or use other initialization strategy.'
@@ -805,6 +807,10 @@ def MindtPy_initialization(self):
             self.integer_list.append(self.curr_int_sol)
             fixed_nlp, fixed_nlp_result = self.solve_subproblem()
             self.handle_nlp_subproblem_tc(fixed_nlp, fixed_nlp_result)
+            self.integer_solution_to_cuts_index[self.curr_int_sol] = [
+                1,
+                len(self.mip.MindtPy_utils.cuts.oa_cuts),
+            ]
         elif config.init_strategy == 'FP':
             self.init_rNLP()
             self.fp_loop()
@@ -834,12 +840,35 @@ def init_rNLP(self, add_oa_cuts=True):
             results = self.nlp_opt.solve(
                 self.rnlp,
                 tee=config.nlp_solver_tee,
-                load_solutions=self.load_solutions,
+                load_solutions=self.nlp_load_solutions,
                 **nlp_args,
             )
             if len(results.solution) > 0:
                 self.rnlp.solutions.load_from(results)
         subprob_terminate_cond = results.solver.termination_condition
+
+        # Sometimes, the NLP solver might be trapped in a infeasible solution if the objective function is nonlinear and partition_obj_nonlinear_terms is True. If this happens, we will use the original objective function instead.
+        if (
+            subprob_terminate_cond == tc.infeasible
+            and config.partition_obj_nonlinear_terms
+            and self.rnlp.MindtPy_utils.objective_list[0].expr.polynomial_degree()
+            not in self.mip_objective_polynomial_degree
+        ):
+            config.logger.info(
+                'Initial relaxed NLP problem is infeasible. This might be related to partition_obj_nonlinear_terms. Trying to solve it again without partitioning nonlinear objective function.'
+            )
+            self.rnlp.MindtPy_utils.objective.deactivate()
+            self.rnlp.MindtPy_utils.objective_list[0].activate()
+            results = self.nlp_opt.solve(
+                self.rnlp,
+                tee=config.nlp_solver_tee,
+                load_solutions=self.nlp_load_solutions,
+                **nlp_args,
+            )
+            if len(results.solution) > 0:
+                self.rnlp.solutions.load_from(results)
+            subprob_terminate_cond = results.solver.termination_condition
+
         if subprob_terminate_cond in {tc.optimal, tc.feasible, tc.locallyOptimal}:
             main_objective = MindtPy.objective_list[-1]
             if subprob_terminate_cond == tc.optimal:
@@ -880,12 +909,14 @@ def init_rNLP(self, add_oa_cuts=True):
                     self.rnlp.MindtPy_utils.variable_list,
                     self.mip.MindtPy_utils.variable_list,
                     config,
+                    ignore_integrality=True,
                 )
                 if config.init_strategy == 'FP':
                     copy_var_list_values(
                         self.rnlp.MindtPy_utils.variable_list,
                         self.working_model.MindtPy_utils.variable_list,
                         config,
+                        ignore_integrality=True,
                     )
                 self.add_cuts(
                     dual_values=dual_values,
@@ -962,7 +993,10 @@ def init_max_binaries(self):
         mip_args = dict(config.mip_solver_args)
         update_solver_timelimit(self.mip_opt, config.mip_solver, self.timing, config)
         results = self.mip_opt.solve(
-            m, tee=config.mip_solver_tee, load_solutions=self.load_solutions, **mip_args
+            m,
+            tee=config.mip_solver_tee,
+            load_solutions=self.mip_load_solutions,
+            **mip_args,
         )
         if len(results.solution) > 0:
             m.solutions.load_from(results)
@@ -1050,7 +1084,7 @@ def solve_subproblem(self):
                         0, c_geq * (rhs - value(c.body))
                     )
                 except (ValueError, OverflowError) as e:
-                    config.logger.error(e)
+                    config.logger.error(e, exc_info=True)
                     self.fixed_nlp.tmp_duals[c] = None
                     evaluation_error = True
             if evaluation_error:
@@ -1067,8 +1101,9 @@ def solve_subproblem(self):
                 tolerance=config.constraint_tolerance,
             )
         except InfeasibleConstraintException as e:
+            config.logger.error(e, exc_info=True)
             config.logger.error(
-                str(e) + '\nInfeasibility detected in deactivate_trivial_constraints.'
+                'Infeasibility detected in deactivate_trivial_constraints.'
             )
             results = SolverResults()
             results.solver.termination_condition = tc.infeasible
@@ -1081,7 +1116,7 @@ def solve_subproblem(self):
                 results = self.nlp_opt.solve(
                     self.fixed_nlp,
                     tee=config.nlp_solver_tee,
-                    load_solutions=self.load_solutions,
+                    load_solutions=self.nlp_load_solutions,
                     **nlp_args,
                 )
                 if len(results.solution) > 0:
@@ -1219,7 +1254,18 @@ def handle_subproblem_infeasible(self, fixed_nlp, cb_opt=None):
         # TODO try something else? Reinitialize with different initial
         # value?
         config = self.config
-        config.logger.info('NLP subproblem was locally infeasible.')
+        config.logger.info(
+            self.infeasible_fixed_nlp_log_formatter.format(
+                ' ',
+                self.nlp_iter,
+                'Fixed NLP',
+                'Infeasible',
+                self.primal_bound,
+                self.dual_bound,
+                self.rel_gap,
+                get_main_elapsed_time(self.timing),
+            )
+        )
         self.nlp_infeasible_counter += 1
         if config.calculate_dual_at_solution:
             for c in fixed_nlp.MindtPy_utils.constraint_list:
@@ -1241,7 +1287,6 @@ def handle_subproblem_infeasible(self, fixed_nlp, cb_opt=None):
         #         elif var.has_lb() and abs(value(var) - var.lb) < config.absolute_bound_tolerance:
         #             fixed_nlp.ipopt_zU_out[var] = -1
 
-        config.logger.info('Solving feasibility problem')
         feas_subproblem, feas_subproblem_results = self.solve_feasibility_subproblem()
         # TODO: do we really need this?
         if self.should_terminate:
@@ -1339,12 +1384,20 @@ def solve_feasibility_subproblem(self):
         update_solver_timelimit(
             self.feasibility_nlp_opt, config.nlp_solver, self.timing, config
         )
-        TransformationFactory('contrib.deactivate_trivial_constraints').apply_to(
-            feas_subproblem,
-            tmp=True,
-            ignore_infeasible=False,
-            tolerance=config.constraint_tolerance,
-        )
+        try:
+            TransformationFactory('contrib.deactivate_trivial_constraints').apply_to(
+                self.fixed_nlp,
+                tmp=True,
+                ignore_infeasible=False,
+                tolerance=config.constraint_tolerance,
+            )
+        except InfeasibleConstraintException as e:
+            config.logger.error(
+                str(e) + '\nInfeasibility detected in deactivate_trivial_constraints.'
+            )
+            results = SolverResults()
+            results.solver.termination_condition = tc.infeasible
+            return self.fixed_nlp, results
         with SuppressInfeasibleWarning():
             try:
                 with time_code(self.timing, 'feasibility subproblem'):
@@ -1357,7 +1410,7 @@ def solve_feasibility_subproblem(self):
                     if len(feas_soln.solution) > 0:
                         feas_subproblem.solutions.load_from(feas_soln)
             except (ValueError, OverflowError) as e:
-                config.logger.error(e)
+                config.logger.error(e, exc_info=True)
                 for nlp_var, orig_val in zip(
                     MindtPy.variable_list, self.initial_var_values
                 ):
@@ -1375,6 +1428,18 @@ def solve_feasibility_subproblem(self):
         self.handle_feasibility_subproblem_tc(
             feas_soln.solver.termination_condition, MindtPy
         )
+        config.logger.info(
+            self.fixed_nlp_log_formatter.format(
+                ' ',
+                self.nlp_iter,
+                'Feasibility NLP',
+                value(feas_subproblem.MindtPy_utils.feas_obj),
+                self.primal_bound,
+                self.dual_bound,
+                self.rel_gap,
+                get_main_elapsed_time(self.timing),
+            )
+        )
         MindtPy.feas_opt.deactivate()
         for constr in MindtPy.nonlinear_constraint_list:
             constr.activate()
@@ -1486,9 +1551,8 @@ def fix_dual_bound(self, last_iter_cuts):
             try:
                 self.dual_bound = self.stored_bound[self.primal_bound]
             except KeyError as e:
-                config.logger.error(
-                    str(e) + '\nNo stored bound found. Bound fix failed.'
-                )
+                config.logger.error(e, exc_info=True)
+                config.logger.error('No stored bound found. Bound fix failed.')
         else:
             config.logger.info(
                 'Solve the main problem without the last no_good cut to fix the bound.'
@@ -1502,7 +1566,7 @@ def fix_dual_bound(self, last_iter_cuts):
                 self.handle_nlp_subproblem_tc(fixed_nlp, fixed_nlp_result)
 
             MindtPy = self.mip.MindtPy_utils
-            # deactivate the integer cuts generated after the best solution was found.
+            # Deactivate the integer cuts generated after the best solution was found.
             self.deactivate_no_good_cuts_when_fixing_bound(MindtPy.cuts.no_good_cuts)
             if (
                 config.add_regularization is not None
@@ -1519,7 +1583,7 @@ def fix_dual_bound(self, last_iter_cuts):
             main_mip_results = self.mip_opt.solve(
                 self.mip,
                 tee=config.mip_solver_tee,
-                load_solutions=self.load_solutions,
+                load_solutions=self.mip_load_solutions,
                 **mip_args,
             )
             if len(main_mip_results.solution) > 0:
@@ -1601,19 +1665,20 @@ def solve_main(self):
         # setup main problem
         self.setup_main()
         mip_args = self.set_up_mip_solver()
+        update_solver_timelimit(self.mip_opt, config.mip_solver, self.timing, config)
 
         try:
             main_mip_results = self.mip_opt.solve(
                 self.mip,
                 tee=config.mip_solver_tee,
-                load_solutions=self.load_solutions,
+                load_solutions=self.mip_load_solutions,
                 **mip_args,
             )
             # update_attributes should be before load_from(main_mip_results), since load_from(main_mip_results) may fail.
             if len(main_mip_results.solution) > 0:
                 self.mip.solutions.load_from(main_mip_results)
         except (ValueError, AttributeError, RuntimeError) as e:
-            config.logger.error(e)
+            config.logger.error(e, exc_info=True)
             if config.single_tree:
                 config.logger.warning('Single tree terminate.')
                 if get_main_elapsed_time(self.timing) >= config.time_limit:
@@ -1626,7 +1691,11 @@ def solve_main(self):
                         "No-good cuts are added and GOA algorithm doesn't converge within the time limit. "
                         'No integer solution is found, so the CPLEX solver will report an error status. '
                     )
-            return None, None
+            # Value error will be raised if the MIP problem is unbounded and appsi solver is used when loading solutions. Although the problem is unbounded, a valid result is provided and we do not return None to let the algorithm continue.
+            if 'main_mip_results' in locals():
+                return self.mip, main_mip_results
+            else:
+                return None, None
         if config.solution_pool:
             main_mip_results._solver_model = self.mip_opt._solver_model
             main_mip_results._pyomo_var_to_solver_var_map = (
@@ -1658,11 +1727,12 @@ def solve_fp_main(self):
         config = self.config
         self.setup_fp_main()
         mip_args = self.set_up_mip_solver()
+        update_solver_timelimit(self.mip_opt, config.mip_solver, self.timing, config)
 
         main_mip_results = self.mip_opt.solve(
             self.mip,
             tee=config.mip_solver_tee,
-            load_solutions=self.load_solutions,
+            load_solutions=self.mip_load_solutions,
             **mip_args,
         )
         # update_attributes should be before load_from(main_mip_results), since load_from(main_mip_results) may fail.
@@ -1705,7 +1775,7 @@ def solve_regularization_main(self):
         main_mip_results = self.regularization_mip_opt.solve(
             self.mip,
             tee=config.mip_solver_tee,
-            load_solutions=self.load_solutions,
+            load_solutions=self.regularization_mip_load_solutions,
             **dict(config.mip_solver_args),
         )
         if len(main_mip_results.solution) > 0:
@@ -1791,7 +1861,6 @@ def handle_main_optimal(self, main_mip, update_bound=True):
                     f"Integer variable {var.name} not initialized.  "
                     "Setting it to its lower bound"
                 )
-                # nlp_var.bounds[0]
                 var.set_value(var.lb, skip_validation=True)
         # warm start for the nlp subproblem
         copy_var_list_values(
@@ -1857,11 +1926,6 @@ def handle_main_max_timelimit(self, main_mip, main_mip_results):
         """
         # If we have found a valid feasible solution, we take that. If not, we can at least use the dual bound.
         MindtPy = main_mip.MindtPy_utils
-        self.config.logger.info(
-            'Unable to optimize MILP main problem '
-            'within time limit. '
-            'Using current solver feasible solution.'
-        )
         copy_var_list_values(
             main_mip.MindtPy_utils.variable_list,
             self.fixed_nlp.MindtPy_utils.variable_list,
@@ -1870,10 +1934,10 @@ def handle_main_max_timelimit(self, main_mip, main_mip_results):
         )
         self.update_suboptimal_dual_bound(main_mip_results)
         self.config.logger.info(
-            self.log_formatter.format(
+            self.termination_condition_log_formatter.format(
                 self.mip_iter,
                 'MILP',
-                value(MindtPy.mip_obj.expr),
+                'maxTimeLimit',
                 self.primal_bound,
                 self.dual_bound,
                 self.rel_gap,
@@ -1900,8 +1964,18 @@ def handle_main_unbounded(self, main_mip):
         # to the constraints, and deactivated for the linear main problem.
         config = self.config
         MindtPy = main_mip.MindtPy_utils
+        config.logger.info(
+            self.termination_condition_log_formatter.format(
+                self.mip_iter,
+                'MILP',
+                'Unbounded',
+                self.primal_bound,
+                self.dual_bound,
+                self.rel_gap,
+                get_main_elapsed_time(self.timing),
+            )
+        )
         config.logger.warning(
-            'main MILP was unbounded. '
             'Resolving with arbitrary bound values of (-{0:.10g}, {0:.10g}) on the objective. '
             'You can change this bound with the option obj_bound.'.format(
                 config.obj_bound
@@ -1917,7 +1991,7 @@ def handle_main_unbounded(self, main_mip):
             main_mip_results = self.mip_opt.solve(
                 main_mip,
                 tee=config.mip_solver_tee,
-                load_solutions=self.load_solutions,
+                load_solutions=self.mip_load_solutions,
                 **config.mip_solver_args,
             )
             if len(main_mip_results.solution) > 0:
@@ -2200,6 +2274,11 @@ def check_subsolver_validity(self):
             raise ValueError(self.config.mip_solver + ' is not available.')
         if not self.mip_opt.license_is_valid():
             raise ValueError(self.config.mip_solver + ' is not licensed.')
+        if self.config.mip_solver == "appsi_highs":
+            if self.mip_opt.version() < (1, 7, 0):
+                raise ValueError(
+                    "MindtPy requires the use of HIGHS version 1.7.0 or higher for full compatibility."
+                )
         if not self.nlp_opt.available():
             raise ValueError(self.config.nlp_solver + ' is not available.')
         if not self.nlp_opt.license_is_valid():
@@ -2247,15 +2326,15 @@ def check_config(self):
                 config.mip_solver = 'cplex_persistent'
 
         # related to https://github.com/Pyomo/pyomo/issues/2363
+        if 'appsi' in config.mip_solver:
+            self.mip_load_solutions = False
+        if 'appsi' in config.nlp_solver:
+            self.nlp_load_solutions = False
         if (
-            'appsi' in config.mip_solver
-            or 'appsi' in config.nlp_solver
-            or (
-                config.mip_regularization_solver is not None
-                and 'appsi' in config.mip_regularization_solver
-            )
+            config.mip_regularization_solver is not None
+            and 'appsi' in config.mip_regularization_solver
         ):
-            self.load_solutions = False
+            self.regularization_mip_load_solutions = False
 
     ################################################################################################################################
     # Feasibility Pump
@@ -2308,8 +2387,9 @@ def solve_fp_subproblem(self):
                 tolerance=config.constraint_tolerance,
             )
         except InfeasibleConstraintException as e:
+            config.logger.error(e, exc_info=True)
             config.logger.error(
-                str(e) + '\nInfeasibility detected in deactivate_trivial_constraints.'
+                'Infeasibility detected in deactivate_trivial_constraints.'
             )
             results = SolverResults()
             results.solver.termination_condition = tc.infeasible
@@ -2322,7 +2402,7 @@ def solve_fp_subproblem(self):
                 results = self.nlp_opt.solve(
                     fp_nlp,
                     tee=config.nlp_solver_tee,
-                    load_solutions=self.load_solutions,
+                    load_solutions=self.nlp_load_solutions,
                     **nlp_args,
                 )
                 if len(results.solution) > 0:
@@ -2342,6 +2422,7 @@ def handle_fp_subproblem_optimal(self, fp_nlp):
             fp_nlp.MindtPy_utils.variable_list,
             self.working_model.MindtPy_utils.variable_list,
             self.config,
+            ignore_integrality=True,
         )
         add_orthogonality_cuts(self.working_model, self.mip, self.config)
 
@@ -2526,7 +2607,7 @@ def fp_loop(self):
             self.working_model.MindtPy_utils.cuts.del_component('fp_orthogonality_cuts')
 
     def initialize_mip_problem(self):
-        '''Deactivate the nonlinear constraints to create the MIP problem.'''
+        """Deactivate the nonlinear constraints to create the MIP problem."""
         # if single tree is activated, we need to add bounds for unbounded variables in nonlinear constraints to avoid unbounded main problem.
         config = self.config
         if config.single_tree:
@@ -2557,7 +2638,7 @@ def initialize_mip_problem(self):
 
         self.fixed_nlp = self.working_model.clone()
         TransformationFactory('core.fix_integer_vars').apply_to(self.fixed_nlp)
-        initialize_feas_subproblem(self.fixed_nlp, config)
+        initialize_feas_subproblem(self.fixed_nlp, config.feasibility_norm)
 
     def initialize_subsolvers(self):
         """Initialize and set options for MIP and NLP subsolvers."""
@@ -2585,7 +2666,7 @@ def initialize_subsolvers(self):
             self.nlp_opt, config.nlp_solver, config
         )
         set_solver_constraint_violation_tolerance(
-            self.feasibility_nlp_opt, config.nlp_solver, config
+            self.feasibility_nlp_opt, config.nlp_solver, config, warm_start=False
         )
 
         self.set_appsi_solver_update_config()
@@ -2886,6 +2967,10 @@ def MindtPy_iteration_loop(self):
                         skip_fixed=False,
                     )
                     if self.curr_int_sol not in set(self.integer_list):
+                        # Call the NLP pre-solve callback
+                        with time_code(self.timing, 'Call before subproblem solve'):
+                            config.call_before_subproblem_solve(self.fixed_nlp)
+
                         fixed_nlp, fixed_nlp_result = self.solve_subproblem()
                         self.handle_nlp_subproblem_tc(fixed_nlp, fixed_nlp_result)
 
@@ -2897,6 +2982,10 @@ def MindtPy_iteration_loop(self):
                 # Solve NLP subproblem
                 # The constraint linearization happens in the handlers
                 if not config.solution_pool:
+                    # Call the NLP pre-solve callback
+                    with time_code(self.timing, 'Call before subproblem solve'):
+                        config.call_before_subproblem_solve(self.fixed_nlp)
+
                     fixed_nlp, fixed_nlp_result = self.solve_subproblem()
                     self.handle_nlp_subproblem_tc(fixed_nlp, fixed_nlp_result)
 
@@ -2929,6 +3018,11 @@ def MindtPy_iteration_loop(self):
                                 continue
                             else:
                                 self.integer_list.append(self.curr_int_sol)
+
+                        # Call the NLP pre-solve callback
+                        with time_code(self.timing, 'Call before subproblem solve'):
+                            config.call_before_subproblem_solve(self.fixed_nlp)
+
                         fixed_nlp, fixed_nlp_result = self.solve_subproblem()
                         self.handle_nlp_subproblem_tc(fixed_nlp, fixed_nlp_result)
 
@@ -2942,10 +3036,12 @@ def MindtPy_iteration_loop(self):
 
         # if add_no_good_cuts is True, the bound obtained in the last iteration is no reliable.
         # we correct it after the iteration.
+        # There is no need to fix the dual bound if no feasible solution has been found.
         if (
             (config.add_no_good_cuts or config.use_tabu_list)
             and not self.should_terminate
             and config.add_regularization is None
+            and self.best_solution_found is not None
         ):
             self.fix_dual_bound(self.last_iter_cuts)
         config.logger.info(
diff --git a/pyomo/contrib/mindtpy/config_options.py b/pyomo/contrib/mindtpy/config_options.py
index ed0c86baae9..5d265e72cf6 100644
--- a/pyomo/contrib/mindtpy/config_options.py
+++ b/pyomo/contrib/mindtpy/config_options.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # -*- coding: utf-8 -*-
 import logging
 from pyomo.common.config import (
@@ -312,6 +323,15 @@ def _add_common_configs(CONFIG):
             doc='Callback hook after a solution of the main problem.',
         ),
     )
+    CONFIG.declare(
+        'call_before_subproblem_solve',
+        ConfigValue(
+            default=_DoNothing(),
+            domain=None,
+            description='Function to be executed before every subproblem',
+            doc='Callback hook before a solution of the nonlinear subproblem.',
+        ),
+    )
     CONFIG.declare(
         'call_after_subproblem_solve',
         ConfigValue(
@@ -538,7 +558,7 @@ def _add_subsolver_configs(CONFIG):
                     'cplex_persistent',
                     'appsi_cplex',
                     'appsi_gurobi',
-                    # 'appsi_highs', TODO: feasibility pump now fails with appsi_highs #2951
+                    'appsi_highs',
                 ]
             ),
             description='MIP subsolver name',
@@ -620,7 +640,7 @@ def _add_subsolver_configs(CONFIG):
                     'cplex_persistent',
                     'appsi_cplex',
                     'appsi_gurobi',
-                    # 'appsi_highs',
+                    'appsi_highs',
                 ]
             ),
             description='MIP subsolver for regularization problem',
diff --git a/pyomo/contrib/mindtpy/cut_generation.py b/pyomo/contrib/mindtpy/cut_generation.py
index 28d302104a3..e932755e9fd 100644
--- a/pyomo/contrib/mindtpy/cut_generation.py
+++ b/pyomo/contrib/mindtpy/cut_generation.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -210,8 +210,8 @@ def add_oa_cuts_for_grey_box(
                             target_model_grey_box.inputs.values()
                         )
                     )
+                    - (output - value(output))
                 )
-                - (output - value(output))
                 - (slack_var if config.add_slack else 0)
                 <= 0
             )
@@ -271,8 +271,9 @@ def add_ecp_cuts(
                 try:
                     upper_slack = constr.uslack()
                 except (ValueError, OverflowError) as e:
+                    config.logger.error(e, exc_info=True)
                     config.logger.error(
-                        str(e) + '\nConstraint {} has caused either a '
+                        'Constraint {} has caused either a '
                         'ValueError or OverflowError.'
                         '\n'.format(constr)
                     )
@@ -300,8 +301,9 @@ def add_ecp_cuts(
                 try:
                     lower_slack = constr.lslack()
                 except (ValueError, OverflowError) as e:
+                    config.logger.error(e, exc_info=True)
                     config.logger.error(
-                        str(e) + '\nConstraint {} has caused either a '
+                        'Constraint {} has caused either a '
                         'ValueError or OverflowError.'
                         '\n'.format(constr)
                     )
@@ -424,9 +426,9 @@ def add_affine_cuts(target_model, config, timing):
             try:
                 mc_eqn = mc(constr.body)
             except MCPP_Error as e:
+                config.logger.error(e, exc_info=True)
                 config.logger.error(
-                    '\nSkipping constraint %s due to MCPP error %s'
-                    % (constr.name, str(e))
+                    'Skipping constraint %s due to MCPP error' % (constr.name)
                 )
                 continue  # skip to the next constraint
 
diff --git a/pyomo/contrib/mindtpy/extended_cutting_plane.py b/pyomo/contrib/mindtpy/extended_cutting_plane.py
index 446304b1361..7bb3ff783c9 100644
--- a/pyomo/contrib/mindtpy/extended_cutting_plane.py
+++ b/pyomo/contrib/mindtpy/extended_cutting_plane.py
@@ -3,7 +3,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -66,12 +66,6 @@ def MindtPy_iteration_loop(self):
 
             add_ecp_cuts(self.mip, self.jacobians, self.config, self.timing)
 
-        # if add_no_good_cuts is True, the bound obtained in the last iteration is no reliable.
-        # we correct it after the iteration.
-        if (
-            self.config.add_no_good_cuts or self.config.use_tabu_list
-        ) and not self.should_terminate:
-            self.fix_dual_bound(self.last_iter_cuts)
         self.config.logger.info(
             ' ==============================================================================================='
         )
@@ -84,9 +78,12 @@ def check_config(self):
         super().check_config()
 
     def initialize_mip_problem(self):
-        '''Deactivate the nonlinear constraints to create the MIP problem.'''
+        """Deactivate the nonlinear constraints to create the MIP problem."""
         super().initialize_mip_problem()
-        self.jacobians = calc_jacobians(self.mip, self.config)  # preload jacobians
+        self.jacobians = calc_jacobians(
+            self.mip.MindtPy_utils.nonlinear_constraint_list,
+            self.config.differentiate_mode,
+        )  # preload jacobians
         self.mip.MindtPy_utils.cuts.ecp_cuts = ConstraintList(
             doc='Extended Cutting Planes'
         )
@@ -140,7 +137,7 @@ def all_nonlinear_constraint_satisfied(self):
                     lower_slack = nlc.lslack()
                 except (ValueError, OverflowError) as e:
                     # Set lower_slack (upper_slack below) less than -config.ecp_tolerance in this case.
-                    config.logger.error(e)
+                    config.logger.error(e, exc_info=True)
                     lower_slack = -10 * config.ecp_tolerance
                 if lower_slack < -config.ecp_tolerance:
                     config.logger.debug(
@@ -153,7 +150,7 @@ def all_nonlinear_constraint_satisfied(self):
                 try:
                     upper_slack = nlc.uslack()
                 except (ValueError, OverflowError) as e:
-                    config.logger.error(e)
+                    config.logger.error(e, exc_info=True)
                     upper_slack = -10 * config.ecp_tolerance
                 if upper_slack < -config.ecp_tolerance:
                     config.logger.debug(
diff --git a/pyomo/contrib/mindtpy/feasibility_pump.py b/pyomo/contrib/mindtpy/feasibility_pump.py
index 990f56b8f93..5ee1260dd42 100644
--- a/pyomo/contrib/mindtpy/feasibility_pump.py
+++ b/pyomo/contrib/mindtpy/feasibility_pump.py
@@ -3,7 +3,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -44,9 +44,12 @@ def check_config(self):
         super().check_config()
 
     def initialize_mip_problem(self):
-        '''Deactivate the nonlinear constraints to create the MIP problem.'''
+        """Deactivate the nonlinear constraints to create the MIP problem."""
         super().initialize_mip_problem()
-        self.jacobians = calc_jacobians(self.mip, self.config)  # preload jacobians
+        self.jacobians = calc_jacobians(
+            self.mip.MindtPy_utils.nonlinear_constraint_list,
+            self.config.differentiate_mode,
+        )  # preload jacobians
         self.mip.MindtPy_utils.cuts.oa_cuts = ConstraintList(
             doc='Outer approximation cuts'
         )
diff --git a/pyomo/contrib/mindtpy/global_outer_approximation.py b/pyomo/contrib/mindtpy/global_outer_approximation.py
index dfb7ef54630..c43409a8493 100644
--- a/pyomo/contrib/mindtpy/global_outer_approximation.py
+++ b/pyomo/contrib/mindtpy/global_outer_approximation.py
@@ -3,7 +3,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -67,7 +67,7 @@ def check_config(self):
         super().check_config()
 
     def initialize_mip_problem(self):
-        '''Deactivate the nonlinear constraints to create the MIP problem.'''
+        """Deactivate the nonlinear constraints to create the MIP problem."""
         super().initialize_mip_problem()
         self.mip.MindtPy_utils.cuts.aff_cuts = ConstraintList(doc='Affine cuts')
 
@@ -108,4 +108,5 @@ def deactivate_no_good_cuts_when_fixing_bound(self, no_good_cuts):
             if self.config.use_tabu_list:
                 self.integer_list = self.integer_list[:valid_no_good_cuts_num]
         except KeyError as e:
-            self.config.logger.error(str(e) + '\nDeactivating no-good cuts failed.')
+            self.config.logger.error(e, exc_info=True)
+            self.config.logger.error('Deactivating no-good cuts failed.')
diff --git a/pyomo/contrib/mindtpy/outer_approximation.py b/pyomo/contrib/mindtpy/outer_approximation.py
index 6cf0b26cb37..ead5cadfeac 100644
--- a/pyomo/contrib/mindtpy/outer_approximation.py
+++ b/pyomo/contrib/mindtpy/outer_approximation.py
@@ -3,7 +3,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -94,9 +94,12 @@ def check_config(self):
         _MindtPyAlgorithm.check_config(self)
 
     def initialize_mip_problem(self):
-        '''Deactivate the nonlinear constraints to create the MIP problem.'''
+        """Deactivate the nonlinear constraints to create the MIP problem."""
         super().initialize_mip_problem()
-        self.jacobians = calc_jacobians(self.mip, self.config)  # preload jacobians
+        self.jacobians = calc_jacobians(
+            self.mip.MindtPy_utils.nonlinear_constraint_list,
+            self.config.differentiate_mode,
+        )  # preload jacobians
         self.mip.MindtPy_utils.cuts.oa_cuts = ConstraintList(
             doc='Outer approximation cuts'
         )
diff --git a/pyomo/contrib/mindtpy/plugins.py b/pyomo/contrib/mindtpy/plugins.py
index f25706d086a..bf0ab0d1581 100644
--- a/pyomo/contrib/mindtpy/plugins.py
+++ b/pyomo/contrib/mindtpy/plugins.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mindtpy/single_tree.py b/pyomo/contrib/mindtpy/single_tree.py
index 5383624b6aa..6b501ef874d 100644
--- a/pyomo/contrib/mindtpy/single_tree.py
+++ b/pyomo/contrib/mindtpy/single_tree.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -16,12 +16,12 @@
 from pyomo.repn import generate_standard_repn
 import pyomo.core.expr as EXPR
 from math import copysign
-from pyomo.contrib.mindtpy.util import get_integer_solution
-from pyomo.contrib.gdpopt.util import (
+from pyomo.contrib.mindtpy.util import (
+    get_integer_solution,
     copy_var_list_values,
-    get_main_elapsed_time,
-    time_code,
+    set_var_valid_value,
 )
+from pyomo.contrib.gdpopt.util import get_main_elapsed_time, time_code
 from pyomo.opt import TerminationCondition as tc
 from pyomo.core import minimize, value
 from pyomo.core.expr import identify_variables
@@ -35,17 +35,9 @@ class LazyOACallback_cplex(
     """Inherent class in CPLEX to call Lazy callback."""
 
     def copy_lazy_var_list_values(
-        self,
-        opt,
-        from_list,
-        to_list,
-        config,
-        skip_stale=False,
-        skip_fixed=True,
-        ignore_integrality=False,
+        self, opt, from_list, to_list, config, skip_stale=False, skip_fixed=True
     ):
         """This function copies variable values from one list to another.
-
         Rounds to Binary/Integer if necessary.
         Sets to zero for NonNegativeReals if necessary.
 
@@ -54,17 +46,15 @@ def copy_lazy_var_list_values(
         opt : SolverFactory
             The cplex_persistent solver.
         from_list : list
-            The variables that provides the values to copy from.
+            The variable list that provides the values to copy from.
         to_list : list
-            The variables that need to set value.
+            The variable list that needs to set value.
         config : ConfigBlock
             The specific configurations for MindtPy.
         skip_stale : bool, optional
             Whether to skip the stale variables, by default False.
         skip_fixed : bool, optional
             Whether to skip the fixed variables, by default True.
-        ignore_integrality : bool, optional
-            Whether to ignore the integrality of integer variables, by default False.
         """
         for v_from, v_to in zip(from_list, to_list):
             if skip_stale and v_from.stale:
@@ -72,43 +62,13 @@ def copy_lazy_var_list_values(
             if skip_fixed and v_to.is_fixed():
                 continue  # Skip fixed variables.
             v_val = self.get_values(opt._pyomo_var_to_solver_var_map[v_from])
-            try:
-                # We don't want to trigger the reset of the global stale
-                # indicator, so we will set this variable to be "stale",
-                # knowing that set_value will switch it back to "not
-                # stale"
-                v_to.stale = True
-                # NOTE: PEP 2180 changes the var behavior so that domain
-                # / bounds violations no longer generate exceptions (and
-                # instead log warnings).  This means that the following
-                # will always succeed and the ValueError should never be
-                # raised.
-                v_to.set_value(v_val, skip_validation=True)
-            except ValueError as e:
-                # Snap the value to the bounds
-                config.logger.error(e)
-                if (
-                    v_to.has_lb()
-                    and v_val < v_to.lb
-                    and v_to.lb - v_val <= config.variable_tolerance
-                ):
-                    v_to.set_value(v_to.lb, skip_validation=True)
-                elif (
-                    v_to.has_ub()
-                    and v_val > v_to.ub
-                    and v_val - v_to.ub <= config.variable_tolerance
-                ):
-                    v_to.set_value(v_to.ub, skip_validation=True)
-                # ... or the nearest integer
-                elif v_to.is_integer():
-                    rounded_val = int(round(v_val))
-                    if (
-                        ignore_integrality
-                        or abs(v_val - rounded_val) <= config.integer_tolerance
-                    ) and rounded_val in v_to.domain:
-                        v_to.set_value(rounded_val, skip_validation=True)
-                else:
-                    raise
+            set_var_valid_value(
+                v_to,
+                v_val,
+                config.integer_tolerance,
+                config.zero_tolerance,
+                ignore_integrality=False,
+            )
 
     def add_lazy_oa_cuts(
         self,
@@ -309,12 +269,11 @@ def add_lazy_affine_cuts(self, mindtpy_solver, config, opt):
                 try:
                     mc_eqn = mc(constr.body)
                 except MCPP_Error as e:
+                    config.logger.error(e, exc_info=True)
                     config.logger.debug(
-                        'Skipping constraint %s due to MCPP error %s'
-                        % (constr.name, str(e))
+                        'Skipping constraint %s due to MCPP error' % (constr.name)
                     )
                     continue  # skip to the next constraint
-                # TODO: check if the value of ccSlope and cvSlope is not Nan or inf. If so, we skip this.
                 ccSlope = mc_eqn.subcc()
                 cvSlope = mc_eqn.subcv()
                 ccStart = mc_eqn.concave()
@@ -705,10 +664,11 @@ def __call__(self):
         main_mip = self.main_mip
         mindtpy_solver = self.mindtpy_solver
 
+        # The lazy constraint callback may be invoked during MIP start processing. In that case get_solution_source returns mip_start_solution.
         # Reference: https://www.ibm.com/docs/en/icos/22.1.1?topic=SSSA5P_22.1.1/ilog.odms.cplex.help/refpythoncplex/html/cplex.callbacks.SolutionSource-class.htm
         # Another solution source is user_solution = 118, but it will not be encountered in LazyConstraintCallback.
-        config.logger.debug(
-            "Solution source: %s (111 node_solution, 117 heuristic_solution, 119 mipstart_solution)".format(
+        config.logger.info(
+            "Solution source: {} (111 node_solution, 117 heuristic_solution, 119 mipstart_solution)".format(
                 self.get_solution_source()
             )
         )
@@ -717,6 +677,7 @@ def __call__(self):
         # Lazy constraints separated when processing a MIP start will be discarded after that MIP start has been processed.
         # This means that the callback may have to separate the same constraint again for the next MIP start or for a solution that is found later in the solution process.
         # https://www.ibm.com/docs/en/icos/22.1.1?topic=SSSA5P_22.1.1/ilog.odms.cplex.help/refpythoncplex/html/cplex.callbacks.LazyConstraintCallback-class.htm
+        # For the MINLP3_simple example, all the solutions are obtained from mip_start (solution source). Therefore, it will not go to a branch and bound process.Cause an error output.
         if (
             self.get_solution_source()
             != cplex.callbacks.SolutionSource.mipstart_solution
@@ -727,6 +688,7 @@ def __call__(self):
             mindtpy_solver.mip_start_lazy_oa_cuts = []
 
         if mindtpy_solver.should_terminate:
+            # TODO: check the performance difference if we don't use self.abort() and let cplex terminate by itself.
             self.abort()
             return
         self.handle_lazy_main_feasible_solution(main_mip, mindtpy_solver, config, opt)
@@ -744,9 +706,9 @@ def __call__(self):
                         mindtpy_solver.mip, None, mindtpy_solver, config, opt
                     )
                 except ValueError as e:
+                    config.logger.error(e, exc_info=True)
                     config.logger.error(
-                        str(e)
-                        + "\nUsually this error is caused by the MIP start solution causing a math domain error. "
+                        "Usually this error is caused by the MIP start solution causing a math domain error. "
                         "We will skip it."
                     )
                     return
@@ -782,6 +744,7 @@ def __call__(self):
                 )
             )
             mindtpy_solver.results.solver.termination_condition = tc.optimal
+            # TODO: check the performance difference if we don't use self.abort() and let cplex terminate by itself.
             self.abort()
             return
 
@@ -810,6 +773,9 @@ def __call__(self):
             mindtpy_solver.integer_list.append(mindtpy_solver.curr_int_sol)
 
         # solve subproblem
+        # Call the NLP pre-solve callback
+        with time_code(mindtpy_solver.timing, 'Call before subproblem solve'):
+            config.call_before_subproblem_solve(mindtpy_solver.fixed_nlp)
         # The constraint linearization happens in the handlers
         fixed_nlp, fixed_nlp_result = mindtpy_solver.solve_subproblem()
         # add oa cuts
@@ -909,19 +875,7 @@ def LazyOACallback_gurobi(cb_m, cb_opt, cb_where, mindtpy_solver, config):
             if mindtpy_solver.dual_bound != mindtpy_solver.dual_bound_progress[0]:
                 mindtpy_solver.add_regularization()
 
-        if (
-            abs(mindtpy_solver.primal_bound - mindtpy_solver.dual_bound)
-            <= config.absolute_bound_tolerance
-        ):
-            config.logger.info(
-                'MindtPy exiting on bound convergence. '
-                '|Primal Bound: {} - Dual Bound: {}| <= (absolute tolerance {})  \n'.format(
-                    mindtpy_solver.primal_bound,
-                    mindtpy_solver.dual_bound,
-                    config.absolute_bound_tolerance,
-                )
-            )
-            mindtpy_solver.results.solver.termination_condition = tc.optimal
+        if mindtpy_solver.bounds_converged() or mindtpy_solver.reached_time_limit():
             cb_opt._solver_model.terminate()
             return
 
@@ -952,15 +906,34 @@ def LazyOACallback_gurobi(cb_m, cb_opt, cb_where, mindtpy_solver, config):
                     )
                 return
             elif config.strategy == 'OA':
+                # Refer to the official document of GUROBI.
+                # Your callback should be prepared to cut off solutions that violate any of your lazy constraints, including those that have already been added. Node solutions will usually respect previously added lazy constraints, but not always.
+                # https://www.gurobi.com/documentation/current/refman/cs_cb_addlazy.html
+                # If this happens, MindtPy will look for the index of corresponding cuts, instead of solving the fixed-NLP again.
+                begin_index, end_index = mindtpy_solver.integer_solution_to_cuts_index[
+                    mindtpy_solver.curr_int_sol
+                ]
+                for ind in range(begin_index, end_index + 1):
+                    cb_opt.cbLazy(mindtpy_solver.mip.MindtPy_utils.cuts.oa_cuts[ind])
                 return
         else:
             mindtpy_solver.integer_list.append(mindtpy_solver.curr_int_sol)
+            if config.strategy == 'OA':
+                cut_ind = len(mindtpy_solver.mip.MindtPy_utils.cuts.oa_cuts)
 
         # solve subproblem
+        # Call the NLP pre-solve callback
+        with time_code(mindtpy_solver.timing, 'Call before subproblem solve'):
+            config.call_before_subproblem_solve(mindtpy_solver.fixed_nlp)
         # The constraint linearization happens in the handlers
         fixed_nlp, fixed_nlp_result = mindtpy_solver.solve_subproblem()
 
         mindtpy_solver.handle_nlp_subproblem_tc(fixed_nlp, fixed_nlp_result, cb_opt)
+        if config.strategy == 'OA':
+            # store the cut index corresponding to current integer solution.
+            mindtpy_solver.integer_solution_to_cuts_index[
+                mindtpy_solver.curr_int_sol
+            ] = [cut_ind + 1, len(mindtpy_solver.mip.MindtPy_utils.cuts.oa_cuts)]
 
 
 def handle_lazy_main_feasible_solution_gurobi(cb_m, cb_opt, mindtpy_solver, config):
diff --git a/pyomo/contrib/mindtpy/tabu_list.py b/pyomo/contrib/mindtpy/tabu_list.py
index 313bd6f6271..15c1d3b3a2b 100644
--- a/pyomo/contrib/mindtpy/tabu_list.py
+++ b/pyomo/contrib/mindtpy/tabu_list.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mindtpy/tests/MINLP2_simple.py b/pyomo/contrib/mindtpy/tests/MINLP2_simple.py
index 10da243d332..f3fd51af79a 100644
--- a/pyomo/contrib/mindtpy/tests/MINLP2_simple.py
+++ b/pyomo/contrib/mindtpy/tests/MINLP2_simple.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mindtpy/tests/MINLP3_simple.py b/pyomo/contrib/mindtpy/tests/MINLP3_simple.py
index f387b0e26a1..a17659e0c51 100644
--- a/pyomo/contrib/mindtpy/tests/MINLP3_simple.py
+++ b/pyomo/contrib/mindtpy/tests/MINLP3_simple.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mindtpy/tests/MINLP4_simple.py b/pyomo/contrib/mindtpy/tests/MINLP4_simple.py
index 7b57c6b8f0d..44b6c7df543 100644
--- a/pyomo/contrib/mindtpy/tests/MINLP4_simple.py
+++ b/pyomo/contrib/mindtpy/tests/MINLP4_simple.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # -*- coding: utf-8 -*-
 """ Example 1 in Paper 'Using regularization and second order information in outer approximation for convex MINLP'
 
diff --git a/pyomo/contrib/mindtpy/tests/MINLP5_simple.py b/pyomo/contrib/mindtpy/tests/MINLP5_simple.py
index 5ab5f98b894..d5b04d0915c 100644
--- a/pyomo/contrib/mindtpy/tests/MINLP5_simple.py
+++ b/pyomo/contrib/mindtpy/tests/MINLP5_simple.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # -*- coding: utf-8 -*-
 """Example in paper 'Using regularization and second order information in outer approximation for convex MINLP'
 
diff --git a/pyomo/contrib/mindtpy/tests/MINLP_simple.py b/pyomo/contrib/mindtpy/tests/MINLP_simple.py
index 7454b595986..cde65536f43 100644
--- a/pyomo/contrib/mindtpy/tests/MINLP_simple.py
+++ b/pyomo/contrib/mindtpy/tests/MINLP_simple.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mindtpy/tests/MINLP_simple_grey_box.py b/pyomo/contrib/mindtpy/tests/MINLP_simple_grey_box.py
index 547efc0a74c..412067de0b5 100644
--- a/pyomo/contrib/mindtpy/tests/MINLP_simple_grey_box.py
+++ b/pyomo/contrib/mindtpy/tests/MINLP_simple_grey_box.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.common.dependencies import numpy as np
 import pyomo.common.dependencies.scipy.sparse as scipy_sparse
 from pyomo.common.dependencies import attempt_import
@@ -114,7 +125,7 @@ def evaluate_jacobian_equality_constraints(self):
             """Evaluate the Jacobian of the equality constraints."""
             return None
 
-        '''
+        """
         def _extract_and_assemble_fim(self):
             M = np.zeros((self.n_parameters, self.n_parameters))
             for i in range(self.n_parameters):
@@ -122,7 +133,7 @@ def _extract_and_assemble_fim(self):
                     M[i,k] = self._input_values[self.ele_to_order[(i,k)]]
 
             return M
-        '''
+        """
 
         def evaluate_jacobian_outputs(self):
             """Evaluate the Jacobian of the outputs."""
diff --git a/pyomo/contrib/mindtpy/tests/__init__.py b/pyomo/contrib/mindtpy/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/mindtpy/tests/__init__.py
+++ b/pyomo/contrib/mindtpy/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/mindtpy/tests/constraint_qualification_example.py b/pyomo/contrib/mindtpy/tests/constraint_qualification_example.py
index 6038f9a74eb..c0849094300 100644
--- a/pyomo/contrib/mindtpy/tests/constraint_qualification_example.py
+++ b/pyomo/contrib/mindtpy/tests/constraint_qualification_example.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # -*- coding: utf-8 -*-
 """ Example of constraint qualification.
 
diff --git a/pyomo/contrib/mindtpy/tests/eight_process_problem.py b/pyomo/contrib/mindtpy/tests/eight_process_problem.py
index d3876a9dc44..ed9059ae4ae 100644
--- a/pyomo/contrib/mindtpy/tests/eight_process_problem.py
+++ b/pyomo/contrib/mindtpy/tests/eight_process_problem.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # -*- coding: utf-8 -*-
 """Re-implementation of eight-process problem.
 
diff --git a/pyomo/contrib/mindtpy/tests/feasibility_pump1.py b/pyomo/contrib/mindtpy/tests/feasibility_pump1.py
index e0a611c1ed2..fec750f9f12 100644
--- a/pyomo/contrib/mindtpy/tests/feasibility_pump1.py
+++ b/pyomo/contrib/mindtpy/tests/feasibility_pump1.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # -*- coding: utf-8 -*-
 """Example 1 in paper 'A Feasibility Pump for mixed integer nonlinear programs'
 
diff --git a/pyomo/contrib/mindtpy/tests/feasibility_pump2.py b/pyomo/contrib/mindtpy/tests/feasibility_pump2.py
index 48b98dc5800..d739e4efbbe 100644
--- a/pyomo/contrib/mindtpy/tests/feasibility_pump2.py
+++ b/pyomo/contrib/mindtpy/tests/feasibility_pump2.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # -*- coding: utf-8 -*-
 """Example 2 in paper 'A Feasibility Pump for mixed integer nonlinear programs'
 
diff --git a/pyomo/contrib/mindtpy/tests/from_proposal.py b/pyomo/contrib/mindtpy/tests/from_proposal.py
index 6ddab15ee53..f29fbcd2cf7 100644
--- a/pyomo/contrib/mindtpy/tests/from_proposal.py
+++ b/pyomo/contrib/mindtpy/tests/from_proposal.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # -*- coding: utf-8 -*-
 """
 See David Bernal PhD proposal example.
diff --git a/pyomo/contrib/mindtpy/tests/nonconvex1.py b/pyomo/contrib/mindtpy/tests/nonconvex1.py
index 94a4de29405..71b7e22af96 100644
--- a/pyomo/contrib/mindtpy/tests/nonconvex1.py
+++ b/pyomo/contrib/mindtpy/tests/nonconvex1.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # -*- coding: utf-8 -*-
 """Problem A in paper 'Outer approximation algorithms for separable nonconvex mixed-integer nonlinear programs'
 
diff --git a/pyomo/contrib/mindtpy/tests/nonconvex2.py b/pyomo/contrib/mindtpy/tests/nonconvex2.py
index 525db1292c1..94c519ab0e1 100644
--- a/pyomo/contrib/mindtpy/tests/nonconvex2.py
+++ b/pyomo/contrib/mindtpy/tests/nonconvex2.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # -*- coding: utf-8 -*-
 """Problem B in paper 'Outer approximation algorithms for separable nonconvex mixed-integer nonlinear programs'
 
diff --git a/pyomo/contrib/mindtpy/tests/nonconvex3.py b/pyomo/contrib/mindtpy/tests/nonconvex3.py
index b08deb67b63..5b6a1de8d7d 100644
--- a/pyomo/contrib/mindtpy/tests/nonconvex3.py
+++ b/pyomo/contrib/mindtpy/tests/nonconvex3.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # -*- coding: utf-8 -*-
 """Problem C in paper 'Outer approximation algorithms for separable nonconvex mixed-integer nonlinear programs'.
 The problem in the paper has two optimal solution. Variable y4 and y6 are symmetric. Therefore, we remove variable y6 for simplification.
diff --git a/pyomo/contrib/mindtpy/tests/nonconvex4.py b/pyomo/contrib/mindtpy/tests/nonconvex4.py
index c30fb9922a0..3b7f6660ddf 100644
--- a/pyomo/contrib/mindtpy/tests/nonconvex4.py
+++ b/pyomo/contrib/mindtpy/tests/nonconvex4.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # -*- coding: utf-8 -*-
 """Problem D in paper 'Outer approximation algorithms for separable nonconvex mixed-integer nonlinear programs'
 
diff --git a/pyomo/contrib/mindtpy/tests/online_doc_example.py b/pyomo/contrib/mindtpy/tests/online_doc_example.py
index d741455e7f7..17a758552c0 100644
--- a/pyomo/contrib/mindtpy/tests/online_doc_example.py
+++ b/pyomo/contrib/mindtpy/tests/online_doc_example.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mindtpy/tests/test_mindtpy.py b/pyomo/contrib/mindtpy/tests/test_mindtpy.py
index e872eccc670..618967be00f 100644
--- a/pyomo/contrib/mindtpy/tests/test_mindtpy.py
+++ b/pyomo/contrib/mindtpy/tests/test_mindtpy.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -56,7 +56,12 @@
 QCP_model._generate_model()
 extreme_model_list = [LP_model.model, QCP_model.model]
 
-required_solvers = ('ipopt', 'glpk')
+if SolverFactory('appsi_highs').available(exception_flag=False) and SolverFactory(
+    'appsi_highs'
+).version() >= (1, 7, 0):
+    required_solvers = ('ipopt', 'appsi_highs')
+else:
+    required_solvers = ('ipopt', 'glpk')
 if all(SolverFactory(s).available(exception_flag=False) for s in required_solvers):
     subsolvers_available = True
 else:
@@ -101,6 +106,30 @@ def test_OA_rNLP(self):
                 )
                 self.check_optimal_solution(model)
 
+    def test_OA_callback(self):
+        """Test the outer approximation decomposition algorithm."""
+        with SolverFactory('mindtpy') as opt:
+
+            def callback(model):
+                model.Y[1].value = 0
+                model.Y[2].value = 0
+                model.Y[3].value = 0
+
+            model = SimpleMINLP2()
+            # The callback function will make the OA method cycling.
+            results = opt.solve(
+                model,
+                strategy='OA',
+                init_strategy='rNLP',
+                mip_solver=required_solvers[1],
+                nlp_solver=required_solvers[0],
+                call_before_subproblem_solve=callback,
+            )
+            self.assertIs(
+                results.solver.termination_condition, TerminationCondition.feasible
+            )
+            self.assertAlmostEqual(value(results.problem.lower_bound), 5, places=1)
+
     def test_OA_extreme_model(self):
         """Test the outer approximation decomposition algorithm."""
         with SolverFactory('mindtpy') as opt:
@@ -327,6 +356,7 @@ def test_OA_APPSI_ipopt(self):
                     value(model.objective.expr), model.optimal_value, places=1
                 )
 
+    # CYIPOPT will raise WARNING (W1002) during loading solution.
     @unittest.skipUnless(
         SolverFactory('cyipopt').available(exception_flag=False),
         "APPSI_IPOPT not available.",
diff --git a/pyomo/contrib/mindtpy/tests/test_mindtpy_ECP.py b/pyomo/contrib/mindtpy/tests/test_mindtpy_ECP.py
index b5bfbe62553..dda0f74147e 100644
--- a/pyomo/contrib/mindtpy/tests/test_mindtpy_ECP.py
+++ b/pyomo/contrib/mindtpy/tests/test_mindtpy_ECP.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # -*- coding: utf-8 -*-
 """Tests for the MindtPy solver."""
 import pyomo.common.unittest as unittest
@@ -12,7 +23,13 @@
 from pyomo.environ import SolverFactory, value
 from pyomo.opt import TerminationCondition
 
-required_solvers = ('ipopt', 'glpk')
+if SolverFactory('appsi_highs').available(exception_flag=False) and SolverFactory(
+    'appsi_highs'
+).version() >= (1, 7, 0):
+    required_solvers = ('ipopt', 'appsi_highs')
+else:
+    required_solvers = ('ipopt', 'glpk')
+
 if all(SolverFactory(s).available(exception_flag=False) for s in required_solvers):
     subsolvers_available = True
 else:
diff --git a/pyomo/contrib/mindtpy/tests/test_mindtpy_feas_pump.py b/pyomo/contrib/mindtpy/tests/test_mindtpy_feas_pump.py
index 697a63d17c8..0baa361910e 100644
--- a/pyomo/contrib/mindtpy/tests/test_mindtpy_feas_pump.py
+++ b/pyomo/contrib/mindtpy/tests/test_mindtpy_feas_pump.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # -*- coding: utf-8 -*-
 """Tests for the MindtPy solver."""
 import pyomo.common.unittest as unittest
@@ -17,8 +28,13 @@
 from pyomo.contrib.mindtpy.tests.feasibility_pump1 import FeasPump1
 from pyomo.contrib.mindtpy.tests.feasibility_pump2 import FeasPump2
 
-required_solvers = ('ipopt', 'cplex')
-# TODO: 'appsi_highs' will fail here.
+if SolverFactory('appsi_highs').available(exception_flag=False) and SolverFactory(
+    'appsi_highs'
+).version() >= (1, 7, 0):
+    required_solvers = ('ipopt', 'appsi_highs')
+else:
+    required_solvers = ('ipopt', 'glpk')
+
 if all(SolverFactory(s).available(exception_flag=False) for s in required_solvers):
     subsolvers_available = True
 else:
@@ -69,6 +85,22 @@ def test_FP(self):
                 log_infeasible_constraints(model)
                 self.assertTrue(is_feasible(model, self.get_config(opt)))
 
+    def test_FP_L1_norm(self):
+        """Test the feasibility pump algorithm."""
+        with SolverFactory('mindtpy') as opt:
+            for model in model_list:
+                model = model.clone()
+                results = opt.solve(
+                    model,
+                    strategy='FP',
+                    mip_solver=required_solvers[1],
+                    nlp_solver=required_solvers[0],
+                    absolute_bound_tolerance=1e-5,
+                    fp_main_norm='L1',
+                )
+                log_infeasible_constraints(model)
+                self.assertTrue(is_feasible(model, self.get_config(opt)))
+
     def test_FP_OA_8PP(self):
         """Test the FP-OA algorithm."""
         with SolverFactory('mindtpy') as opt:
diff --git a/pyomo/contrib/mindtpy/tests/test_mindtpy_global.py b/pyomo/contrib/mindtpy/tests/test_mindtpy_global.py
index 0fa19b30d9c..07774805364 100644
--- a/pyomo/contrib/mindtpy/tests/test_mindtpy_global.py
+++ b/pyomo/contrib/mindtpy/tests/test_mindtpy_global.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # -*- coding: utf-8 -*-
 """Tests for the MindtPy solver."""
 import pyomo.common.unittest as unittest
diff --git a/pyomo/contrib/mindtpy/tests/test_mindtpy_global_lp_nlp.py b/pyomo/contrib/mindtpy/tests/test_mindtpy_global_lp_nlp.py
index 259cfe9dd7c..792bdb8d993 100644
--- a/pyomo/contrib/mindtpy/tests/test_mindtpy_global_lp_nlp.py
+++ b/pyomo/contrib/mindtpy/tests/test_mindtpy_global_lp_nlp.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # -*- coding: utf-8 -*-
 """Tests for global LP/NLP in the MindtPy solver."""
 import pyomo.common.unittest as unittest
diff --git a/pyomo/contrib/mindtpy/tests/test_mindtpy_grey_box.py b/pyomo/contrib/mindtpy/tests/test_mindtpy_grey_box.py
index f84136ca6bf..e01558d48ef 100644
--- a/pyomo/contrib/mindtpy/tests/test_mindtpy_grey_box.py
+++ b/pyomo/contrib/mindtpy/tests/test_mindtpy_grey_box.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -18,7 +18,14 @@
 from pyomo.contrib.mindtpy.tests.MINLP_simple import SimpleMINLP as SimpleMINLP
 
 model_list = [SimpleMINLP(grey_box=True)]
-required_solvers = ('cyipopt', 'glpk')
+
+if SolverFactory('appsi_highs').available(exception_flag=False) and SolverFactory(
+    'appsi_highs'
+).version() >= (1, 7, 0):
+    required_solvers = ('cyipopt', 'appsi_highs')
+else:
+    required_solvers = ('cyipopt', 'glpk')
+
 if all(SolverFactory(s).available(exception_flag=False) for s in required_solvers):
     subsolvers_available = True
 else:
diff --git a/pyomo/contrib/mindtpy/tests/test_mindtpy_lp_nlp.py b/pyomo/contrib/mindtpy/tests/test_mindtpy_lp_nlp.py
index 2662a0e6f56..97f73ece525 100644
--- a/pyomo/contrib/mindtpy/tests/test_mindtpy_lp_nlp.py
+++ b/pyomo/contrib/mindtpy/tests/test_mindtpy_lp_nlp.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mindtpy/tests/test_mindtpy_regularization.py b/pyomo/contrib/mindtpy/tests/test_mindtpy_regularization.py
index 4c2ae4d1220..2e864a49578 100644
--- a/pyomo/contrib/mindtpy/tests/test_mindtpy_regularization.py
+++ b/pyomo/contrib/mindtpy/tests/test_mindtpy_regularization.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # -*- coding: utf-8 -*-
 """Tests for the MindtPy solver."""
 import pyomo.common.unittest as unittest
diff --git a/pyomo/contrib/mindtpy/tests/test_mindtpy_solution_pool.py b/pyomo/contrib/mindtpy/tests/test_mindtpy_solution_pool.py
index 7a9898d3c7b..a41f41d4d65 100644
--- a/pyomo/contrib/mindtpy/tests/test_mindtpy_solution_pool.py
+++ b/pyomo/contrib/mindtpy/tests/test_mindtpy_solution_pool.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """Tests for solution pool in the MindtPy solver."""
 
 from pyomo.core.expr.calculus.diff_with_sympy import differentiate_available
diff --git a/pyomo/contrib/mindtpy/tests/unit_test.py b/pyomo/contrib/mindtpy/tests/unit_test.py
new file mode 100644
index 00000000000..af6ffad282d
--- /dev/null
+++ b/pyomo/contrib/mindtpy/tests/unit_test.py
@@ -0,0 +1,101 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import pyomo.common.unittest as unittest
+from pyomo.contrib.mindtpy.util import set_var_valid_value
+
+from pyomo.environ import Var, Integers, ConcreteModel, Integers
+from pyomo.contrib.mindtpy.algorithm_base_class import _MindtPyAlgorithm
+from pyomo.contrib.mindtpy.config_options import _get_MindtPy_OA_config
+from pyomo.contrib.mindtpy.tests.MINLP5_simple import SimpleMINLP5
+from pyomo.contrib.mindtpy.util import add_var_bound
+
+
+class UnitTestMindtPy(unittest.TestCase):
+    def test_set_var_valid_value(self):
+        m = ConcreteModel()
+        m.x1 = Var(within=Integers, bounds=(-1, 4), initialize=0)
+
+        set_var_valid_value(
+            m.x1,
+            var_val=5,
+            integer_tolerance=1e-6,
+            zero_tolerance=1e-6,
+            ignore_integrality=False,
+        )
+        self.assertEqual(m.x1.value, 4)
+
+        set_var_valid_value(
+            m.x1,
+            var_val=-2,
+            integer_tolerance=1e-6,
+            zero_tolerance=1e-6,
+            ignore_integrality=False,
+        )
+        self.assertEqual(m.x1.value, -1)
+
+        set_var_valid_value(
+            m.x1,
+            var_val=1.1,
+            integer_tolerance=1e-6,
+            zero_tolerance=1e-6,
+            ignore_integrality=True,
+        )
+        self.assertEqual(m.x1.value, 1.1)
+
+        set_var_valid_value(
+            m.x1,
+            var_val=2.00000001,
+            integer_tolerance=1e-6,
+            zero_tolerance=1e-6,
+            ignore_integrality=False,
+        )
+        self.assertEqual(m.x1.value, 2)
+
+        set_var_valid_value(
+            m.x1,
+            var_val=0.0000001,
+            integer_tolerance=1e-9,
+            zero_tolerance=1e-6,
+            ignore_integrality=False,
+        )
+        self.assertEqual(m.x1.value, 0)
+
+    def test_add_var_bound(self):
+        m = SimpleMINLP5().clone()
+        m.x.lb = None
+        m.x.ub = None
+        m.y.lb = None
+        m.y.ub = None
+        solver_object = _MindtPyAlgorithm()
+        solver_object.config = _get_MindtPy_OA_config()
+        solver_object.set_up_solve_data(m)
+        solver_object.create_utility_block(solver_object.working_model, 'MindtPy_utils')
+        add_var_bound(solver_object.working_model, solver_object.config)
+        self.assertEqual(
+            solver_object.working_model.x.lower,
+            -solver_object.config.continuous_var_bound - 1,
+        )
+        self.assertEqual(
+            solver_object.working_model.x.upper,
+            solver_object.config.continuous_var_bound,
+        )
+        self.assertEqual(
+            solver_object.working_model.y.lower,
+            -solver_object.config.integer_var_bound - 1,
+        )
+        self.assertEqual(
+            solver_object.working_model.y.upper, solver_object.config.integer_var_bound
+        )
+
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/pyomo/contrib/mindtpy/util.py b/pyomo/contrib/mindtpy/util.py
index cd2b31e5954..7345af8a3e2 100644
--- a/pyomo/contrib/mindtpy/util.py
+++ b/pyomo/contrib/mindtpy/util.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -23,12 +23,12 @@
     RangeSet,
     ConstraintList,
     TransformationFactory,
+    value,
 )
 from pyomo.repn import generate_standard_repn
 from pyomo.contrib.mcpp.pyomo_mcpp import mcpp_available, McCormick
 from pyomo.contrib.fbbt.fbbt import compute_bounds_on_expr
 import pyomo.core.expr as EXPR
-from pyomo.opt import ProblemSense
 from pyomo.contrib.gdpopt.util import get_main_elapsed_time, time_code
 from pyomo.util.model_size import build_model_size_report
 from pyomo.common.dependencies import attempt_import
@@ -40,27 +40,24 @@
 numpy = attempt_import('numpy')[0]
 
 
-def calc_jacobians(model, config):
+def calc_jacobians(constraint_list, differentiate_mode):
     """Generates a map of jacobians for the variables in the model.
 
     This function generates a map of jacobians corresponding to the variables in the
-    model.
+    constraint list.
 
     Parameters
     ----------
-    model : Pyomo model
-        Target model to calculate jacobian.
-    config : ConfigBlock
-        The specific configurations for MindtPy.
+    constraint_list : List
+        The list of constraints to calculate Jacobians.
+    differentiate_mode : String
+        The differentiate mode to calculate Jacobians.
     """
     # Map nonlinear_constraint --> Map(
     #     variable --> jacobian of constraint w.r.t. variable)
     jacobians = ComponentMap()
-    if config.differentiate_mode == 'reverse_symbolic':
-        mode = EXPR.differentiate.Modes.reverse_symbolic
-    elif config.differentiate_mode == 'sympy':
-        mode = EXPR.differentiate.Modes.sympy
-    for c in model.MindtPy_utils.nonlinear_constraint_list:
+    mode = EXPR.differentiate.Modes(differentiate_mode)
+    for c in constraint_list:
         vars_in_constr = list(EXPR.identify_variables(c.body))
         jac_list = EXPR.differentiate(c.body, wrt_list=vars_in_constr, mode=mode)
         jacobians[c] = ComponentMap(
@@ -69,7 +66,7 @@ def calc_jacobians(model, config):
     return jacobians
 
 
-def initialize_feas_subproblem(m, config):
+def initialize_feas_subproblem(m, feasibility_norm):
     """Adds feasibility slack variables according to config.feasibility_norm (given an infeasible problem).
        Defines the objective function of the feasibility subproblem.
 
@@ -77,14 +74,14 @@ def initialize_feas_subproblem(m, config):
     ----------
     m : Pyomo model
         The feasbility NLP subproblem.
-    config : ConfigBlock
-        The specific configurations for MindtPy.
+    feasibility_norm : String
+        The norm used to generate the objective function.
     """
     MindtPy = m.MindtPy_utils
     # generate new constraints
     for i, constr in enumerate(MindtPy.nonlinear_constraint_list, 1):
         if constr.has_ub():
-            if config.feasibility_norm in {'L1', 'L2'}:
+            if feasibility_norm in {'L1', 'L2'}:
                 MindtPy.feas_opt.feas_constraints.add(
                     constr.body - constr.upper <= MindtPy.feas_opt.slack_var[i]
                 )
@@ -93,7 +90,7 @@ def initialize_feas_subproblem(m, config):
                     constr.body - constr.upper <= MindtPy.feas_opt.slack_var
                 )
         if constr.has_lb():
-            if config.feasibility_norm in {'L1', 'L2'}:
+            if feasibility_norm in {'L1', 'L2'}:
                 MindtPy.feas_opt.feas_constraints.add(
                     constr.body - constr.lower >= -MindtPy.feas_opt.slack_var[i]
                 )
@@ -102,11 +99,11 @@ def initialize_feas_subproblem(m, config):
                     constr.body - constr.lower >= -MindtPy.feas_opt.slack_var
                 )
     # Setup objective function for the feasibility subproblem.
-    if config.feasibility_norm == 'L1':
+    if feasibility_norm == 'L1':
         MindtPy.feas_obj = Objective(
             expr=sum(s for s in MindtPy.feas_opt.slack_var.values()), sense=minimize
         )
-    elif config.feasibility_norm == 'L2':
+    elif feasibility_norm == 'L2':
         MindtPy.feas_obj = Objective(
             expr=sum(s * s for s in MindtPy.feas_opt.slack_var.values()), sense=minimize
         )
@@ -133,12 +130,12 @@ def add_var_bound(model, config):
         for var in EXPR.identify_variables(c.body):
             if var.has_lb() and var.has_ub():
                 continue
-            elif not var.has_lb():
+            if not var.has_lb():
                 if var.is_integer():
                     var.setlb(-config.integer_var_bound - 1)
                 else:
                     var.setlb(-config.continuous_var_bound - 1)
-            elif not var.has_ub():
+            if not var.has_ub():
                 if var.is_integer():
                     var.setub(config.integer_var_bound)
                 else:
@@ -568,7 +565,9 @@ def set_solver_mipgap(opt, solver_name, config):
         opt.options['add_options'].append('option optcr=%s;' % config.mip_solver_mipgap)
 
 
-def set_solver_constraint_violation_tolerance(opt, solver_name, config):
+def set_solver_constraint_violation_tolerance(
+    opt, solver_name, config, warm_start=True
+):
     """Set constraint violation tolerance for solvers.
 
     Parameters
@@ -602,15 +601,16 @@ def set_solver_constraint_violation_tolerance(opt, solver_name, config):
                 opt.options['add_options'].append(
                     'constr_viol_tol ' + str(config.zero_tolerance)
                 )
-                # Ipopt warmstart options
-                opt.options['add_options'].append(
-                    'warm_start_init_point       yes\n'
-                    'warm_start_bound_push       1e-9\n'
-                    'warm_start_bound_frac       1e-9\n'
-                    'warm_start_slack_bound_frac 1e-9\n'
-                    'warm_start_slack_bound_push 1e-9\n'
-                    'warm_start_mult_bound_push  1e-9\n'
-                )
+                if warm_start:
+                    # Ipopt warmstart options
+                    opt.options['add_options'].append(
+                        'warm_start_init_point       yes\n'
+                        'warm_start_bound_push       1e-9\n'
+                        'warm_start_bound_frac       1e-9\n'
+                        'warm_start_slack_bound_frac 1e-9\n'
+                        'warm_start_slack_bound_push 1e-9\n'
+                        'warm_start_mult_bound_push  1e-9\n'
+                    )
             elif config.nlp_solver_args['solver'] == 'conopt':
                 opt.options['add_options'].append(
                     'RTNWMA ' + str(config.zero_tolerance)
@@ -684,41 +684,20 @@ def copy_var_list_values_from_solution_pool(
         Whether to ignore the integrality of integer variables, by default False.
     """
     for v_from, v_to in zip(from_list, to_list):
-        try:
-            if config.mip_solver == 'cplex_persistent':
-                var_val = solver_model.solution.pool.get_values(
-                    solution_name, var_map[v_from]
-                )
-            elif config.mip_solver == 'gurobi_persistent':
-                solver_model.setParam(gurobipy.GRB.Param.SolutionNumber, solution_name)
-                var_val = var_map[v_from].Xn
-            # We don't want to trigger the reset of the global stale
-            # indicator, so we will set this variable to be "stale",
-            # knowing that set_value will switch it back to "not
-            # stale"
-            v_to.stale = True
-            # NOTE: PEP 2180 changes the var behavior so that domain /
-            # bounds violations no longer generate exceptions (and
-            # instead log warnings).  This means that the following will
-            # always succeed and the ValueError should never be raised.
-            v_to.set_value(var_val, skip_validation=True)
-        except ValueError as e:
-            config.logger.error(e)
-            rounded_val = int(round(var_val))
-            # Check to see if this is just a tolerance issue
-            if ignore_integrality and v_to.is_integer():
-                v_to.set_value(var_val, skip_validation=True)
-            elif v_to.is_integer() and (
-                abs(var_val - rounded_val) <= config.integer_tolerance
-            ):
-                v_to.set_value(rounded_val, skip_validation=True)
-            elif abs(var_val) <= config.zero_tolerance and 0 in v_to.domain:
-                v_to.set_value(0, skip_validation=True)
-            else:
-                config.logger.error(
-                    'Unknown validation domain error setting variable %s' % (v_to.name,)
-                )
-                raise
+        if config.mip_solver == 'cplex_persistent':
+            var_val = solver_model.solution.pool.get_values(
+                solution_name, var_map[v_from]
+            )
+        elif config.mip_solver == 'gurobi_persistent':
+            solver_model.setParam(gurobipy.GRB.Param.SolutionNumber, solution_name)
+            var_val = var_map[v_from].Xn
+        set_var_valid_value(
+            v_to,
+            var_val,
+            config.integer_tolerance,
+            config.zero_tolerance,
+            ignore_integrality,
+        )
 
 
 class GurobiPersistent4MindtPy(GurobiPersistent):
@@ -743,25 +722,6 @@ def f(gurobi_model, where):
         return f
 
 
-def set_up_logger(config):
-    """Set up the formatter and handler for logger.
-
-    Parameters
-    ----------
-    config : ConfigBlock
-        The specific configurations for MindtPy.
-    """
-    config.logger.handlers.clear()
-    config.logger.propagate = False
-    ch = logging.StreamHandler()
-    ch.setLevel(config.logging_level)
-    # create formatter and add it to the handlers
-    formatter = logging.Formatter('%(message)s')
-    ch.setFormatter(formatter)
-    # add the handlers to logger
-    config.logger.addHandler(ch)
-
-
 def epigraph_reformulation(exp, slack_var_list, constraint_list, use_mcpp, sense):
     """Epigraph reformulation.
 
@@ -965,3 +925,101 @@ def generate_norm_constraint(fp_nlp_model, mip_model, config):
             mip_model.MindtPy_utils.discrete_variable_list,
         ):
             fp_nlp_model.norm_constraint.add(nlp_var - mip_var.value <= rhs)
+
+
+def copy_var_list_values(
+    from_list,
+    to_list,
+    config,
+    skip_stale=False,
+    skip_fixed=True,
+    ignore_integrality=False,
+):
+    """Copy variable values from one list to another.
+    Rounds to Binary/Integer if necessary
+    Sets to zero for NonNegativeReals if necessary
+
+    from_list : list
+        The variables that provide the values to copy from.
+    to_list : list
+        The variables that need to set value.
+    config : ConfigBlock
+        The specific configurations for MindtPy.
+    skip_stale : bool, optional
+        Whether to skip the stale variables, by default False.
+    skip_fixed : bool, optional
+        Whether to skip the fixed variables, by default True.
+    ignore_integrality : bool, optional
+        Whether to ignore the integrality of integer variables, by default False.
+    """
+    for v_from, v_to in zip(from_list, to_list):
+        if skip_stale and v_from.stale:
+            continue  # Skip stale variable values.
+        if skip_fixed and v_to.is_fixed():
+            continue  # Skip fixed variables.
+        var_val = value(v_from, exception=False)
+        set_var_valid_value(
+            v_to,
+            var_val,
+            config.integer_tolerance,
+            config.zero_tolerance,
+            ignore_integrality,
+        )
+
+
+def set_var_valid_value(
+    var, var_val, integer_tolerance, zero_tolerance, ignore_integrality
+):
+    """This function tries to set a valid value for variable with the given input.
+    Rounds to Binary/Integer if necessary.
+    Sets to zero for NonNegativeReals if necessary.
+
+    Parameters
+    ----------
+    var : Var
+        The variable that needs to set value.
+    var_val : float
+        The desired value to set for var.
+    integer_tolerance: float
+        Tolerance on integral values.
+    zero_tolerance: float
+        Tolerance on variable equal to zero.
+    ignore_integrality : bool, optional
+        Whether to ignore the integrality of integer variables, by default False.
+
+    Raises
+    ------
+    ValueError
+        Cannot successfully set the value to the variable.
+    """
+    # NOTE: PEP 2180 changes the var behavior so that domain
+    # bounds violations no longer generate exceptions (and
+    # instead log warnings).  This means that the set_value method
+    # will always succeed and the ValueError should never be raised.
+
+    # We don't want to trigger the reset of the global stale
+    # indicator, so we will set this variable to be "stale",
+    # knowing that set_value will switch it back to "not stale".
+    var.stale = True
+    rounded_val = int(round(var_val))
+    if (
+        var_val in var.domain
+        and not ((var.has_lb() and var_val < var.lb))
+        and not ((var.has_ub() and var_val > var.ub))
+    ):
+        var.set_value(var_val)
+    elif var.has_lb() and var_val < var.lb:
+        var.set_value(var.lb)
+    elif var.has_ub() and var_val > var.ub:
+        var.set_value(var.ub)
+    elif ignore_integrality and var.is_integer():
+        var.set_value(var_val, skip_validation=True)
+    elif var.is_integer() and (math.fabs(var_val - rounded_val) <= integer_tolerance):
+        var.set_value(rounded_val)
+    elif abs(var_val) <= zero_tolerance and 0 in var.domain:
+        var.set_value(0)
+    else:
+        raise ValueError(
+            "set_var_valid_value failed with variable {}, value = {} and rounded value = {}"
+            "".format(var.name, var_val, rounded_val)
+        )
diff --git a/pyomo/contrib/mpc/README.md b/pyomo/contrib/mpc/README.md
new file mode 100644
index 00000000000..7e03163f703
--- /dev/null
+++ b/pyomo/contrib/mpc/README.md
@@ -0,0 +1,34 @@
+# Pyomo MPC
+
+Pyomo MPC is an extension for developing model predictive control simulations
+using Pyomo models. Please see the
+[documentation](https://pyomo.readthedocs.io/en/stable/contributed_packages/mpc/index.html)
+for more detailed information.
+
+Pyomo MPC helps with, among other things, the following use cases:
+- Transferring values between different points in time in a dynamic model
+(e.g. to initialize a dynamic model to its initial conditions)
+- Extracting or loading disturbances and inputs from or to models, and storing
+these in model-agnostic, easily JSON-serializable data structures
+- Constructing common modeling components, such as weighted-least-squares
+tracking objective functions, piecewise-constant input constraints, or
+terminal region constraints.
+
+## Citation
+
+If you use Pyomo MPC in your research, please cite the following paper, which
+discusses the motivation for the Pyomo MPC data structures and the underlying
+Pyomo features that make them possible.
+```bibtex
+@article{parker2023mpc,
+title = {Model predictive control simulations with block-hierarchical differential-algebraic process models},
+journal = {Journal of Process Control},
+volume = {132},
+pages = {103113},
+year = {2023},
+issn = {0959-1524},
+doi = {https://doi.org/10.1016/j.jprocont.2023.103113},
+url = {https://www.sciencedirect.com/science/article/pii/S0959152423002007},
+author = {Robert B. Parker and Bethany L. Nicholson and John D. Siirola and Lorenz T. Biegler},
+}
+```
diff --git a/pyomo/contrib/mpc/__init__.py b/pyomo/contrib/mpc/__init__.py
index da977f365d2..2e1c51e154f 100644
--- a/pyomo/contrib/mpc/__init__.py
+++ b/pyomo/contrib/mpc/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/data/__init__.py b/pyomo/contrib/mpc/data/__init__.py
index 9061fda4bfd..6051f4ba3a2 100644
--- a/pyomo/contrib/mpc/data/__init__.py
+++ b/pyomo/contrib/mpc/data/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/data/convert.py b/pyomo/contrib/mpc/data/convert.py
index f1d35592a9f..10885370032 100644
--- a/pyomo/contrib/mpc/data/convert.py
+++ b/pyomo/contrib/mpc/data/convert.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/data/dynamic_data_base.py b/pyomo/contrib/mpc/data/dynamic_data_base.py
index c0223d2dcbe..5e567f060cf 100644
--- a/pyomo/contrib/mpc/data/dynamic_data_base.py
+++ b/pyomo/contrib/mpc/data/dynamic_data_base.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/data/find_nearest_index.py b/pyomo/contrib/mpc/data/find_nearest_index.py
index 0875bde63e9..c53a7a79841 100644
--- a/pyomo/contrib/mpc/data/find_nearest_index.py
+++ b/pyomo/contrib/mpc/data/find_nearest_index.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/data/get_cuid.py b/pyomo/contrib/mpc/data/get_cuid.py
index 1f229b35645..ef0df7ea679 100644
--- a/pyomo/contrib/mpc/data/get_cuid.py
+++ b/pyomo/contrib/mpc/data/get_cuid.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -16,14 +16,13 @@
 
 
 def get_indexed_cuid(var, sets=None, dereference=None, context=None):
-    """
-    Attempts to convert the provided "var" object into a CUID with
-    with wildcards.
+    """Attempt to convert the provided "var" object into a CUID with wildcards
 
     Arguments
     ---------
     var:
-        Object to process
+        Object to process. May be a VarData, IndexedVar (reference or otherwise),
+        ComponentUID, slice, or string.
     sets: Tuple of sets
         Sets to use if slicing a vardata object
     dereference: None or int
@@ -32,6 +31,11 @@ def get_indexed_cuid(var, sets=None, dereference=None, context=None):
     context: Block
         Block with respect to which slices and CUIDs will be generated
 
+    Returns
+    -------
+    ``ComponentUID``
+        ComponentUID corresponding to the provided ``var`` and sets
+
     """
     # TODO: Does this function have a good name?
     # Should this function be generalized beyond a single indexing set?
diff --git a/pyomo/contrib/mpc/data/interval_data.py b/pyomo/contrib/mpc/data/interval_data.py
index cdd3b0e37dc..54b7ca7e906 100644
--- a/pyomo/contrib/mpc/data/interval_data.py
+++ b/pyomo/contrib/mpc/data/interval_data.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/data/scalar_data.py b/pyomo/contrib/mpc/data/scalar_data.py
index 5426921ef06..b67384c8159 100644
--- a/pyomo/contrib/mpc/data/scalar_data.py
+++ b/pyomo/contrib/mpc/data/scalar_data.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/data/series_data.py b/pyomo/contrib/mpc/data/series_data.py
index d09ab8cae24..c812e76c9fc 100644
--- a/pyomo/contrib/mpc/data/series_data.py
+++ b/pyomo/contrib/mpc/data/series_data.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/data/tests/__init__.py b/pyomo/contrib/mpc/data/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/mpc/data/tests/__init__.py
+++ b/pyomo/contrib/mpc/data/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/mpc/data/tests/test_convert.py b/pyomo/contrib/mpc/data/tests/test_convert.py
index 0f8a4623e20..dda3583cb00 100644
--- a/pyomo/contrib/mpc/data/tests/test_convert.py
+++ b/pyomo/contrib/mpc/data/tests/test_convert.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/data/tests/test_find_nearest_index.py b/pyomo/contrib/mpc/data/tests/test_find_nearest_index.py
index e90024ef108..8fb92e17534 100644
--- a/pyomo/contrib/mpc/data/tests/test_find_nearest_index.py
+++ b/pyomo/contrib/mpc/data/tests/test_find_nearest_index.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/data/tests/test_get_cuid.py b/pyomo/contrib/mpc/data/tests/test_get_cuid.py
index 30ba2b58b1b..66bfb613bcb 100644
--- a/pyomo/contrib/mpc/data/tests/test_get_cuid.py
+++ b/pyomo/contrib/mpc/data/tests/test_get_cuid.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/data/tests/test_interval_data.py b/pyomo/contrib/mpc/data/tests/test_interval_data.py
index 8afe3eb3021..b208c9066f9 100644
--- a/pyomo/contrib/mpc/data/tests/test_interval_data.py
+++ b/pyomo/contrib/mpc/data/tests/test_interval_data.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/data/tests/test_scalar_data.py b/pyomo/contrib/mpc/data/tests/test_scalar_data.py
index 110ed749bda..6522242e267 100644
--- a/pyomo/contrib/mpc/data/tests/test_scalar_data.py
+++ b/pyomo/contrib/mpc/data/tests/test_scalar_data.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/data/tests/test_series_data.py b/pyomo/contrib/mpc/data/tests/test_series_data.py
index e32559ac074..88b672279f2 100644
--- a/pyomo/contrib/mpc/data/tests/test_series_data.py
+++ b/pyomo/contrib/mpc/data/tests/test_series_data.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/examples/__init__.py b/pyomo/contrib/mpc/examples/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/mpc/examples/__init__.py
+++ b/pyomo/contrib/mpc/examples/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/mpc/examples/cstr/__init__.py b/pyomo/contrib/mpc/examples/cstr/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/mpc/examples/cstr/__init__.py
+++ b/pyomo/contrib/mpc/examples/cstr/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/mpc/examples/cstr/model.py b/pyomo/contrib/mpc/examples/cstr/model.py
index d794084f122..376e77186dd 100644
--- a/pyomo/contrib/mpc/examples/cstr/model.py
+++ b/pyomo/contrib/mpc/examples/cstr/model.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/examples/cstr/run_mpc.py b/pyomo/contrib/mpc/examples/cstr/run_mpc.py
index 86ae7e4e47b..588ed7d49fe 100644
--- a/pyomo/contrib/mpc/examples/cstr/run_mpc.py
+++ b/pyomo/contrib/mpc/examples/cstr/run_mpc.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/examples/cstr/run_openloop.py b/pyomo/contrib/mpc/examples/cstr/run_openloop.py
index 36ddb990545..66fd0680a01 100644
--- a/pyomo/contrib/mpc/examples/cstr/run_openloop.py
+++ b/pyomo/contrib/mpc/examples/cstr/run_openloop.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/examples/cstr/tests/__init__.py b/pyomo/contrib/mpc/examples/cstr/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/mpc/examples/cstr/tests/__init__.py
+++ b/pyomo/contrib/mpc/examples/cstr/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/mpc/examples/cstr/tests/test_mpc.py b/pyomo/contrib/mpc/examples/cstr/tests/test_mpc.py
index 741a1533da3..e808b8fc414 100644
--- a/pyomo/contrib/mpc/examples/cstr/tests/test_mpc.py
+++ b/pyomo/contrib/mpc/examples/cstr/tests/test_mpc.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/examples/cstr/tests/test_openloop.py b/pyomo/contrib/mpc/examples/cstr/tests/test_openloop.py
index 218865ceabb..c21cb55233e 100644
--- a/pyomo/contrib/mpc/examples/cstr/tests/test_openloop.py
+++ b/pyomo/contrib/mpc/examples/cstr/tests/test_openloop.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/interfaces/__init__.py b/pyomo/contrib/mpc/interfaces/__init__.py
index 8e02003f99e..9b70a983e24 100644
--- a/pyomo/contrib/mpc/interfaces/__init__.py
+++ b/pyomo/contrib/mpc/interfaces/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/interfaces/copy_values.py b/pyomo/contrib/mpc/interfaces/copy_values.py
index 896656b230d..faf1594f114 100644
--- a/pyomo/contrib/mpc/interfaces/copy_values.py
+++ b/pyomo/contrib/mpc/interfaces/copy_values.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/interfaces/load_data.py b/pyomo/contrib/mpc/interfaces/load_data.py
index efa9515901e..b1851c3aa51 100644
--- a/pyomo/contrib/mpc/interfaces/load_data.py
+++ b/pyomo/contrib/mpc/interfaces/load_data.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/interfaces/model_interface.py b/pyomo/contrib/mpc/interfaces/model_interface.py
index 35f81af4a7a..9a30878c921 100644
--- a/pyomo/contrib/mpc/interfaces/model_interface.py
+++ b/pyomo/contrib/mpc/interfaces/model_interface.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/interfaces/tests/__init__.py b/pyomo/contrib/mpc/interfaces/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/mpc/interfaces/tests/__init__.py
+++ b/pyomo/contrib/mpc/interfaces/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/mpc/interfaces/tests/test_interface.py b/pyomo/contrib/mpc/interfaces/tests/test_interface.py
index 65ffc7bb40a..e67e58bf900 100644
--- a/pyomo/contrib/mpc/interfaces/tests/test_interface.py
+++ b/pyomo/contrib/mpc/interfaces/tests/test_interface.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/interfaces/tests/test_var_linker.py b/pyomo/contrib/mpc/interfaces/tests/test_var_linker.py
index ceec9fada36..e169af686f3 100644
--- a/pyomo/contrib/mpc/interfaces/tests/test_var_linker.py
+++ b/pyomo/contrib/mpc/interfaces/tests/test_var_linker.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/interfaces/var_linker.py b/pyomo/contrib/mpc/interfaces/var_linker.py
index fd831c9a2c1..87831379204 100644
--- a/pyomo/contrib/mpc/interfaces/var_linker.py
+++ b/pyomo/contrib/mpc/interfaces/var_linker.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/modeling/__init__.py b/pyomo/contrib/mpc/modeling/__init__.py
index 0eb255a9f56..a174bafc944 100644
--- a/pyomo/contrib/mpc/modeling/__init__.py
+++ b/pyomo/contrib/mpc/modeling/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/modeling/constraints.py b/pyomo/contrib/mpc/modeling/constraints.py
index 6fb6a311afb..e6a1edf648b 100644
--- a/pyomo/contrib/mpc/modeling/constraints.py
+++ b/pyomo/contrib/mpc/modeling/constraints.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/modeling/cost_expressions.py b/pyomo/contrib/mpc/modeling/cost_expressions.py
index 65a376e42d2..aeb26705a38 100644
--- a/pyomo/contrib/mpc/modeling/cost_expressions.py
+++ b/pyomo/contrib/mpc/modeling/cost_expressions.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/modeling/terminal.py b/pyomo/contrib/mpc/modeling/terminal.py
index c25efca280a..d2118c7d92e 100644
--- a/pyomo/contrib/mpc/modeling/terminal.py
+++ b/pyomo/contrib/mpc/modeling/terminal.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/modeling/tests/__init__.py b/pyomo/contrib/mpc/modeling/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/mpc/modeling/tests/__init__.py
+++ b/pyomo/contrib/mpc/modeling/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/mpc/modeling/tests/test_cost_expressions.py b/pyomo/contrib/mpc/modeling/tests/test_cost_expressions.py
index 5db390ffa47..67c474f7722 100644
--- a/pyomo/contrib/mpc/modeling/tests/test_cost_expressions.py
+++ b/pyomo/contrib/mpc/modeling/tests/test_cost_expressions.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/modeling/tests/test_input_constraints.py b/pyomo/contrib/mpc/modeling/tests/test_input_constraints.py
index e3ba3bf3760..be9edad37b9 100644
--- a/pyomo/contrib/mpc/modeling/tests/test_input_constraints.py
+++ b/pyomo/contrib/mpc/modeling/tests/test_input_constraints.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/mpc/modeling/tests/test_terminal.py b/pyomo/contrib/mpc/modeling/tests/test_terminal.py
index b835f0b1087..ef89fe24b57 100644
--- a/pyomo/contrib/mpc/modeling/tests/test_terminal.py
+++ b/pyomo/contrib/mpc/modeling/tests/test_terminal.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/multistart/__init__.py b/pyomo/contrib/multistart/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/multistart/__init__.py
+++ b/pyomo/contrib/multistart/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/multistart/high_conf_stop.py b/pyomo/contrib/multistart/high_conf_stop.py
index 96b350557ae..ce24d2dc1fc 100644
--- a/pyomo/contrib/multistart/high_conf_stop.py
+++ b/pyomo/contrib/multistart/high_conf_stop.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """Utility functions for the high confidence stopping rule.
 
 This stopping criterion operates by estimating the amount of missing optima,
diff --git a/pyomo/contrib/multistart/multi.py b/pyomo/contrib/multistart/multi.py
index 867d47d4951..377ac8182e2 100644
--- a/pyomo/contrib/multistart/multi.py
+++ b/pyomo/contrib/multistart/multi.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/multistart/plugins.py b/pyomo/contrib/multistart/plugins.py
index 297b2f059cc..f094e2f58cc 100644
--- a/pyomo/contrib/multistart/plugins.py
+++ b/pyomo/contrib/multistart/plugins.py
@@ -1,2 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+
 def load():
     import pyomo.contrib.multistart.multi
diff --git a/pyomo/contrib/multistart/reinit.py b/pyomo/contrib/multistart/reinit.py
index de10fe3ba8b..2b097bbc898 100644
--- a/pyomo/contrib/multistart/reinit.py
+++ b/pyomo/contrib/multistart/reinit.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """Helper functions for variable reinitialization."""
 
 import logging
diff --git a/pyomo/contrib/multistart/test_multi.py b/pyomo/contrib/multistart/test_multi.py
index 16c8563ae9e..f8103eed3b8 100644
--- a/pyomo/contrib/multistart/test_multi.py
+++ b/pyomo/contrib/multistart/test_multi.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import logging
 from itertools import product
 
diff --git a/pyomo/contrib/parmest/__init__.py b/pyomo/contrib/parmest/__init__.py
index d340885b3fd..e7d513dd95c 100644
--- a/pyomo/contrib/parmest/__init__.py
+++ b/pyomo/contrib/parmest/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/parmest/examples/__init__.py b/pyomo/contrib/parmest/examples/__init__.py
index d93cfd77b3c..a4a626013c4 100644
--- a/pyomo/contrib/parmest/examples/__init__.py
+++ b/pyomo/contrib/parmest/examples/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/parmest/examples/reaction_kinetics/__init__.py b/pyomo/contrib/parmest/examples/reaction_kinetics/__init__.py
index d93cfd77b3c..a4a626013c4 100644
--- a/pyomo/contrib/parmest/examples/reaction_kinetics/__init__.py
+++ b/pyomo/contrib/parmest/examples/reaction_kinetics/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/parmest/examples/reaction_kinetics/simple_reaction_parmest_example.py b/pyomo/contrib/parmest/examples/reaction_kinetics/simple_reaction_parmest_example.py
index 719a930251c..5c8a0219946 100644
--- a/pyomo/contrib/parmest/examples/reaction_kinetics/simple_reaction_parmest_example.py
+++ b/pyomo/contrib/parmest/examples/reaction_kinetics/simple_reaction_parmest_example.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -18,6 +18,7 @@
 Code provided by Paul Akula.
 '''
 
+import pyomo.environ as pyo
 from pyomo.environ import (
     ConcreteModel,
     Param,
@@ -32,6 +33,7 @@
     value,
 )
 import pyomo.contrib.parmest.parmest as parmest
+from pyomo.contrib.parmest.experiment import Experiment
 
 
 def simple_reaction_model(data):
@@ -72,7 +74,62 @@ def total_cost_rule(m):
     return model
 
 
+# For this experiment class, data is dictionary
+class SimpleReactionExperiment(Experiment):
+
+    def __init__(self, data):
+        self.data = data
+        self.model = None
+
+    def create_model(self):
+        self.model = simple_reaction_model(self.data)
+
+    def label_model(self):
+
+        m = self.model
+
+        m.experiment_outputs = pyo.Suffix(direction=pyo.Suffix.LOCAL)
+        m.experiment_outputs.update(
+            [(m.x1, self.data['x1']), (m.x2, self.data['x2']), (m.y, self.data['y'])]
+        )
+
+        return m
+
+    def get_labeled_model(self):
+        self.create_model()
+        m = self.label_model()
+
+        return m
+
+
+# k[2] fixed
+class SimpleReactionExperimentK2Fixed(SimpleReactionExperiment):
+
+    def label_model(self):
+
+        m = super().label_model()
+
+        m.unknown_parameters = pyo.Suffix(direction=pyo.Suffix.LOCAL)
+        m.unknown_parameters.update((k, pyo.ComponentUID(k)) for k in [m.k[1]])
+
+        return m
+
+
+# k[2] variable
+class SimpleReactionExperimentK2Variable(SimpleReactionExperiment):
+
+    def label_model(self):
+
+        m = super().label_model()
+
+        m.unknown_parameters = pyo.Suffix(direction=pyo.Suffix.LOCAL)
+        m.unknown_parameters.update((k, pyo.ComponentUID(k)) for k in [m.k[1], m.k[2]])
+
+        return m
+
+
 def main():
+
     # Data from Table 5.2 in  Y. Bard, "Nonlinear Parameter Estimation", (pg. 124)
     data = [
         {'experiment': 1, 'x1': 0.1, 'x2': 100, 'y': 0.98},
@@ -92,21 +149,34 @@ def main():
         {'experiment': 15, 'x1': 0.1, 'x2': 300, 'y': 0.006},
     ]
 
+    # Create an experiment list with k[2] fixed
+    exp_list = []
+    for i in range(len(data)):
+        exp_list.append(SimpleReactionExperimentK2Fixed(data[i]))
+
+    # View one model
+    # exp0_model = exp_list[0].get_labeled_model()
+    # exp0_model.pprint()
+
     # =======================================================================
     # Parameter estimation without covariance estimate
     # Only estimate the parameter k[1]. The parameter k[2] will remain fixed
     # at its initial value
-    theta_names = ['k[1]']
-    pest = parmest.Estimator(simple_reaction_model, data, theta_names)
+
+    pest = parmest.Estimator(exp_list)
     obj, theta = pest.theta_est()
     print(obj)
     print(theta)
     print()
 
+    # Create an experiment list with k[2] variable
+    exp_list = []
+    for i in range(len(data)):
+        exp_list.append(SimpleReactionExperimentK2Variable(data[i]))
+
     # =======================================================================
     # Estimate both k1 and k2 and compute the covariance matrix
-    theta_names = ['k']
-    pest = parmest.Estimator(simple_reaction_model, data, theta_names)
+    pest = parmest.Estimator(exp_list)
     n = 15  # total number of data points used in the objective (y in 15 scenarios)
     obj, theta, cov = pest.theta_est(calc_cov=True, cov_n=n)
     print(obj)
diff --git a/pyomo/contrib/parmest/examples/reactor_design/__init__.py b/pyomo/contrib/parmest/examples/reactor_design/__init__.py
index d93cfd77b3c..a4a626013c4 100644
--- a/pyomo/contrib/parmest/examples/reactor_design/__init__.py
+++ b/pyomo/contrib/parmest/examples/reactor_design/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/parmest/examples/reactor_design/bootstrap_example.py b/pyomo/contrib/parmest/examples/reactor_design/bootstrap_example.py
index 16ae9343dfd..598fef32b60 100644
--- a/pyomo/contrib/parmest/examples/reactor_design/bootstrap_example.py
+++ b/pyomo/contrib/parmest/examples/reactor_design/bootstrap_example.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -13,31 +13,27 @@
 from os.path import join, abspath, dirname
 import pyomo.contrib.parmest.parmest as parmest
 from pyomo.contrib.parmest.examples.reactor_design.reactor_design import (
-    reactor_design_model,
+    ReactorDesignExperiment,
 )
 
 
 def main():
-    # Vars to estimate
-    theta_names = ["k1", "k2", "k3"]
 
-    # Data
+    # Read in data
     file_dirname = dirname(abspath(str(__file__)))
     file_name = abspath(join(file_dirname, "reactor_data.csv"))
     data = pd.read_csv(file_name)
 
-    # Sum of squared error function
-    def SSE(model, data):
-        expr = (
-            (float(data.iloc[0]["ca"]) - model.ca) ** 2
-            + (float(data.iloc[0]["cb"]) - model.cb) ** 2
-            + (float(data.iloc[0]["cc"]) - model.cc) ** 2
-            + (float(data.iloc[0]["cd"]) - model.cd) ** 2
-        )
-        return expr
-
-    # Create an instance of the parmest estimator
-    pest = parmest.Estimator(reactor_design_model, data, theta_names, SSE)
+    # Create an experiment list
+    exp_list = []
+    for i in range(data.shape[0]):
+        exp_list.append(ReactorDesignExperiment(data, i))
+
+    # View one model
+    # exp0_model = exp_list[0].get_labeled_model()
+    # exp0_model.pprint()
+
+    pest = parmest.Estimator(exp_list, obj_function='SSE')
 
     # Parameter estimation
     obj, theta = pest.theta_est()
diff --git a/pyomo/contrib/parmest/examples/reactor_design/confidence_region_example.py b/pyomo/contrib/parmest/examples/reactor_design/confidence_region_example.py
new file mode 100644
index 00000000000..73129baf5cb
--- /dev/null
+++ b/pyomo/contrib/parmest/examples/reactor_design/confidence_region_example.py
@@ -0,0 +1,51 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import pandas as pd
+from os.path import join, abspath, dirname
+import pyomo.contrib.parmest.parmest as parmest
+from pyomo.contrib.parmest.examples.reactor_design.reactor_design import (
+    ReactorDesignExperiment,
+)
+
+
+def main():
+
+    # Read in data
+    file_dirname = dirname(abspath(str(__file__)))
+    file_name = abspath(join(file_dirname, "reactor_data.csv"))
+    data = pd.read_csv(file_name)
+
+    # Create an experiment list
+    exp_list = []
+    for i in range(data.shape[0]):
+        exp_list.append(ReactorDesignExperiment(data, i))
+
+    # View one model
+    # exp0_model = exp_list[0].get_labeled_model()
+    # exp0_model.pprint()
+
+    pest = parmest.Estimator(exp_list, obj_function='SSE')
+
+    # Parameter estimation
+    obj, theta = pest.theta_est()
+
+    # Bootstrapping
+    bootstrap_theta = pest.theta_est_bootstrap(10)
+    print(bootstrap_theta)
+
+    # Confidence region test
+    CR = pest.confidence_region_test(bootstrap_theta, "MVN", [0.5, 0.75, 1.0])
+    print(CR)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/pyomo/contrib/parmest/examples/reactor_design/datarec_example.py b/pyomo/contrib/parmest/examples/reactor_design/datarec_example.py
index 507a3ee7582..be08e727be9 100644
--- a/pyomo/contrib/parmest/examples/reactor_design/datarec_example.py
+++ b/pyomo/contrib/parmest/examples/reactor_design/datarec_example.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,24 +9,90 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
+import pyomo.environ as pyo
 from pyomo.common.dependencies import numpy as np, pandas as pd
 import pyomo.contrib.parmest.parmest as parmest
 from pyomo.contrib.parmest.examples.reactor_design.reactor_design import (
     reactor_design_model,
+    ReactorDesignExperiment,
 )
 
 np.random.seed(1234)
 
 
-def reactor_design_model_for_datarec(data):
-    # Unfix inlet concentration for data rec
-    model = reactor_design_model(data)
-    model.caf.fixed = False
+class ReactorDesignExperimentDataRec(ReactorDesignExperiment):
 
-    return model
+    def __init__(self, data, data_std, experiment_number):
+
+        super().__init__(data, experiment_number)
+        self.data_std = data_std
+
+    def create_model(self):
+
+        self.model = m = reactor_design_model()
+        m.caf.fixed = False
+
+        return m
+
+    def label_model(self):
+
+        m = self.model
+
+        # experiment outputs
+        m.experiment_outputs = pyo.Suffix(direction=pyo.Suffix.LOCAL)
+        m.experiment_outputs.update(
+            [
+                (m.ca, self.data_i['ca']),
+                (m.cb, self.data_i['cb']),
+                (m.cc, self.data_i['cc']),
+                (m.cd, self.data_i['cd']),
+            ]
+        )
+
+        # experiment standard deviations
+        m.experiment_outputs_std = pyo.Suffix(direction=pyo.Suffix.LOCAL)
+        m.experiment_outputs_std.update(
+            [
+                (m.ca, self.data_std['ca']),
+                (m.cb, self.data_std['cb']),
+                (m.cc, self.data_std['cc']),
+                (m.cd, self.data_std['cd']),
+            ]
+        )
+
+        # no unknowns (theta names)
+        m.unknown_parameters = pyo.Suffix(direction=pyo.Suffix.LOCAL)
+
+        return m
+
+
+class ReactorDesignExperimentPostDataRec(ReactorDesignExperiment):
+
+    def __init__(self, data, data_std, experiment_number):
+
+        super().__init__(data, experiment_number)
+        self.data_std = data_std
+
+    def label_model(self):
+
+        m = super().label_model()
+
+        # add experiment standard deviations
+        m.experiment_outputs_std = pyo.Suffix(direction=pyo.Suffix.LOCAL)
+        m.experiment_outputs_std.update(
+            [
+                (m.ca, self.data_std['ca']),
+                (m.cb, self.data_std['cb']),
+                (m.cc, self.data_std['cc']),
+                (m.cd, self.data_std['cd']),
+            ]
+        )
+
+        return m
 
 
 def generate_data():
+
     ### Generate data based on real sv, caf, ca, cb, cc, and cd
     sv_real = 1.05
     caf_real = 10000
@@ -53,24 +119,26 @@ def generate_data():
 
 
 def main():
+
     # Generate data
     data = generate_data()
     data_std = data.std()
 
+    # Create an experiment list
+    exp_list = []
+    for i in range(data.shape[0]):
+        exp_list.append(ReactorDesignExperimentDataRec(data, data_std, i))
+
     # Define sum of squared error objective function for data rec
-    def SSE(model, data):
-        expr = (
-            ((float(data.iloc[0]["ca"]) - model.ca) / float(data_std["ca"])) ** 2
-            + ((float(data.iloc[0]["cb"]) - model.cb) / float(data_std["cb"])) ** 2
-            + ((float(data.iloc[0]["cc"]) - model.cc) / float(data_std["cc"])) ** 2
-            + ((float(data.iloc[0]["cd"]) - model.cd) / float(data_std["cd"])) ** 2
+    def SSE_with_std(model):
+        expr = sum(
+            ((y - y_hat) / model.experiment_outputs_std[y]) ** 2
+            for y, y_hat in model.experiment_outputs.items()
         )
         return expr
 
     ### Data reconciliation
-    theta_names = []  # no variables to estimate, use initialized values
-
-    pest = parmest.Estimator(reactor_design_model_for_datarec, data, theta_names, SSE)
+    pest = parmest.Estimator(exp_list, obj_function=SSE_with_std)
 
     obj, theta, data_rec = pest.theta_est(return_values=["ca", "cb", "cc", "cd", "caf"])
     print(obj)
@@ -83,10 +151,14 @@ def SSE(model, data):
     )
 
     ### Parameter estimation using reconciled data
-    theta_names = ["k1", "k2", "k3"]
     data_rec["sv"] = data["sv"]
 
-    pest = parmest.Estimator(reactor_design_model, data_rec, theta_names, SSE)
+    # make a new list of experiments using reconciled data
+    exp_list = []
+    for i in range(data_rec.shape[0]):
+        exp_list.append(ReactorDesignExperimentPostDataRec(data_rec, data_std, i))
+
+    pest = parmest.Estimator(exp_list, obj_function=SSE_with_std)
     obj, theta = pest.theta_est()
     print(obj)
     print(theta)
diff --git a/pyomo/contrib/parmest/examples/reactor_design/leaveNout_example.py b/pyomo/contrib/parmest/examples/reactor_design/leaveNout_example.py
index cda50ef3efd..9560981ca5c 100644
--- a/pyomo/contrib/parmest/examples/reactor_design/leaveNout_example.py
+++ b/pyomo/contrib/parmest/examples/reactor_design/leaveNout_example.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -13,15 +13,13 @@
 from os.path import join, abspath, dirname
 import pyomo.contrib.parmest.parmest as parmest
 from pyomo.contrib.parmest.examples.reactor_design.reactor_design import (
-    reactor_design_model,
+    ReactorDesignExperiment,
 )
 
 
 def main():
-    # Vars to estimate
-    theta_names = ["k1", "k2", "k3"]
 
-    # Data
+    # Read in data
     file_dirname = dirname(abspath(str(__file__)))
     file_name = abspath(join(file_dirname, "reactor_data.csv"))
     data = pd.read_csv(file_name)
@@ -33,18 +31,16 @@ def main():
     df_sample = data.sample(N, replace=True).reset_index(drop=True)
     data = df_sample + df_rand.dot(df_std) / 10
 
-    # Sum of squared error function
-    def SSE(model, data):
-        expr = (
-            (float(data.iloc[0]["ca"]) - model.ca) ** 2
-            + (float(data.iloc[0]["cb"]) - model.cb) ** 2
-            + (float(data.iloc[0]["cc"]) - model.cc) ** 2
-            + (float(data.iloc[0]["cd"]) - model.cd) ** 2
-        )
-        return expr
+    # Create an experiment list
+    exp_list = []
+    for i in range(data.shape[0]):
+        exp_list.append(ReactorDesignExperiment(data, i))
+
+    # View one model
+    # exp0_model = exp_list[0].get_labeled_model()
+    # exp0_model.pprint()
 
-    # Create an instance of the parmest estimator
-    pest = parmest.Estimator(reactor_design_model, data, theta_names, SSE)
+    pest = parmest.Estimator(exp_list, obj_function='SSE')
 
     # Parameter estimation
     obj, theta = pest.theta_est()
diff --git a/pyomo/contrib/parmest/examples/reactor_design/likelihood_ratio_example.py b/pyomo/contrib/parmest/examples/reactor_design/likelihood_ratio_example.py
index 448354f600a..c2bff254077 100644
--- a/pyomo/contrib/parmest/examples/reactor_design/likelihood_ratio_example.py
+++ b/pyomo/contrib/parmest/examples/reactor_design/likelihood_ratio_example.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -14,31 +14,27 @@
 from os.path import join, abspath, dirname
 import pyomo.contrib.parmest.parmest as parmest
 from pyomo.contrib.parmest.examples.reactor_design.reactor_design import (
-    reactor_design_model,
+    ReactorDesignExperiment,
 )
 
 
 def main():
-    # Vars to estimate
-    theta_names = ["k1", "k2", "k3"]
 
-    # Data
+    # Read in data
     file_dirname = dirname(abspath(str(__file__)))
     file_name = abspath(join(file_dirname, "reactor_data.csv"))
     data = pd.read_csv(file_name)
 
-    # Sum of squared error function
-    def SSE(model, data):
-        expr = (
-            (float(data.iloc[0]["ca"]) - model.ca) ** 2
-            + (float(data.iloc[0]["cb"]) - model.cb) ** 2
-            + (float(data.iloc[0]["cc"]) - model.cc) ** 2
-            + (float(data.iloc[0]["cd"]) - model.cd) ** 2
-        )
-        return expr
-
-    # Create an instance of the parmest estimator
-    pest = parmest.Estimator(reactor_design_model, data, theta_names, SSE)
+    # Create an experiment list
+    exp_list = []
+    for i in range(data.shape[0]):
+        exp_list.append(ReactorDesignExperiment(data, i))
+
+    # View one model
+    # exp0_model = exp_list[0].get_labeled_model()
+    # exp0_model.pprint()
+
+    pest = parmest.Estimator(exp_list, obj_function='SSE')
 
     # Parameter estimation
     obj, theta = pest.theta_est()
diff --git a/pyomo/contrib/parmest/examples/reactor_design/multisensor_data_example.py b/pyomo/contrib/parmest/examples/reactor_design/multisensor_data_example.py
index 10d56c8e457..208981a784a 100644
--- a/pyomo/contrib/parmest/examples/reactor_design/multisensor_data_example.py
+++ b/pyomo/contrib/parmest/examples/reactor_design/multisensor_data_example.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -11,37 +11,81 @@
 
 from pyomo.common.dependencies import pandas as pd
 from os.path import join, abspath, dirname
+import pyomo.environ as pyo
 import pyomo.contrib.parmest.parmest as parmest
 from pyomo.contrib.parmest.examples.reactor_design.reactor_design import (
-    reactor_design_model,
+    ReactorDesignExperiment,
 )
 
 
+class MultisensorReactorDesignExperiment(ReactorDesignExperiment):
+
+    def finalize_model(self):
+
+        m = self.model
+
+        # Experiment inputs values
+        m.sv = self.data_i['sv']
+        m.caf = self.data_i['caf']
+
+        # Experiment output values
+        m.ca = (self.data_i['ca1'] + self.data_i['ca2'] + self.data_i['ca3']) * (1 / 3)
+        m.cb = self.data_i['cb']
+        m.cc = (self.data_i['cc1'] + self.data_i['cc2']) * (1 / 2)
+        m.cd = self.data_i['cd']
+
+        return m
+
+    def label_model(self):
+
+        m = self.model
+
+        m.experiment_outputs = pyo.Suffix(direction=pyo.Suffix.LOCAL)
+        m.experiment_outputs.update(
+            [
+                (m.ca, [self.data_i['ca1'], self.data_i['ca2'], self.data_i['ca3']]),
+                (m.cb, [self.data_i['cb']]),
+                (m.cc, [self.data_i['cc1'], self.data_i['cc2']]),
+                (m.cd, [self.data_i['cd']]),
+            ]
+        )
+
+        m.unknown_parameters = pyo.Suffix(direction=pyo.Suffix.LOCAL)
+        m.unknown_parameters.update(
+            (k, pyo.ComponentUID(k)) for k in [m.k1, m.k2, m.k3]
+        )
+
+        return m
+
+
 def main():
     # Parameter estimation using multisensor data
 
-    # Vars to estimate
-    theta_names = ["k1", "k2", "k3"]
-
-    # Data, includes multiple sensors for ca and cc
+    # Read in data
     file_dirname = dirname(abspath(str(__file__)))
     file_name = abspath(join(file_dirname, "reactor_data_multisensor.csv"))
     data = pd.read_csv(file_name)
 
-    # Sum of squared error function
-    def SSE_multisensor(model, data):
-        expr = (
-            ((float(data.iloc[0]["ca1"]) - model.ca) ** 2) * (1 / 3)
-            + ((float(data.iloc[0]["ca2"]) - model.ca) ** 2) * (1 / 3)
-            + ((float(data.iloc[0]["ca3"]) - model.ca) ** 2) * (1 / 3)
-            + (float(data.iloc[0]["cb"]) - model.cb) ** 2
-            + ((float(data.iloc[0]["cc1"]) - model.cc) ** 2) * (1 / 2)
-            + ((float(data.iloc[0]["cc2"]) - model.cc) ** 2) * (1 / 2)
-            + (float(data.iloc[0]["cd"]) - model.cd) ** 2
-        )
+    # Create an experiment list
+    exp_list = []
+    for i in range(data.shape[0]):
+        exp_list.append(MultisensorReactorDesignExperiment(data, i))
+
+    # Define sum of squared error
+    def SSE_multisensor(model):
+        expr = 0
+        for y, y_hat in model.experiment_outputs.items():
+            num_outputs = len(y_hat)
+            for i in range(num_outputs):
+                expr += ((y - y_hat[i]) ** 2) * (1 / num_outputs)
         return expr
 
-    pest = parmest.Estimator(reactor_design_model, data, theta_names, SSE_multisensor)
+    # View one model
+    # exp0_model = exp_list[0].get_labeled_model()
+    # exp0_model.pprint()
+    # print(SSE_multisensor(exp0_model))
+
+    pest = parmest.Estimator(exp_list, obj_function=SSE_multisensor)
     obj, theta = pest.theta_est()
     print(obj)
     print(theta)
diff --git a/pyomo/contrib/parmest/examples/reactor_design/parameter_estimation_example.py b/pyomo/contrib/parmest/examples/reactor_design/parameter_estimation_example.py
index 43af4fbcb94..a84a3fde5e7 100644
--- a/pyomo/contrib/parmest/examples/reactor_design/parameter_estimation_example.py
+++ b/pyomo/contrib/parmest/examples/reactor_design/parameter_estimation_example.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -13,46 +13,29 @@
 from os.path import join, abspath, dirname
 import pyomo.contrib.parmest.parmest as parmest
 from pyomo.contrib.parmest.examples.reactor_design.reactor_design import (
-    reactor_design_model,
+    ReactorDesignExperiment,
 )
 
 
 def main():
-    # Vars to estimate
-    theta_names = ["k1", "k2", "k3"]
 
-    # Data
+    # Read in data
     file_dirname = dirname(abspath(str(__file__)))
     file_name = abspath(join(file_dirname, "reactor_data.csv"))
     data = pd.read_csv(file_name)
 
-    # Sum of squared error function
-    def SSE(model, data):
-        expr = (
-            (float(data.iloc[0]["ca"]) - model.ca) ** 2
-            + (float(data.iloc[0]["cb"]) - model.cb) ** 2
-            + (float(data.iloc[0]["cc"]) - model.cc) ** 2
-            + (float(data.iloc[0]["cd"]) - model.cd) ** 2
-        )
-        return expr
-
-    # Create an instance of the parmest estimator
-    pest = parmest.Estimator(reactor_design_model, data, theta_names, SSE)
-
-    # Parameter estimation
-    obj, theta = pest.theta_est()
-
-    # Assert statements compare parameter estimation (theta) to an expected value
-    k1_expected = 5.0 / 6.0
-    k2_expected = 5.0 / 3.0
-    k3_expected = 1.0 / 6000.0
-    relative_error = abs(theta["k1"] - k1_expected) / k1_expected
-    assert relative_error < 0.05
-    relative_error = abs(theta["k2"] - k2_expected) / k2_expected
-    assert relative_error < 0.05
-    relative_error = abs(theta["k3"] - k3_expected) / k3_expected
-    assert relative_error < 0.05
-
-
-if __name__ == "__main__":
-    main()
+    # Create an experiment list
+    exp_list = []
+    for i in range(data.shape[0]):
+        exp_list.append(ReactorDesignExperiment(data, i))
+
+    # View one model
+    # exp0_model = exp_list[0].get_labeled_model()
+    # exp0_model.pprint()
+
+    pest = parmest.Estimator(exp_list, obj_function='SSE')
+
+    # Parameter estimation with covariance
+    obj, theta, cov = pest.theta_est(calc_cov=True, cov_n=17)
+    print(obj)
+    print(theta)
diff --git a/pyomo/contrib/parmest/examples/reactor_design/reactor_design.py b/pyomo/contrib/parmest/examples/reactor_design/reactor_design.py
index e86446febd7..a396c1ea721 100644
--- a/pyomo/contrib/parmest/examples/reactor_design/reactor_design.py
+++ b/pyomo/contrib/parmest/examples/reactor_design/reactor_design.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -12,57 +12,46 @@
 Continuously stirred tank reactor model, based on
 pyomo/examples/doc/pyomobook/nonlinear-ch/react_design/ReactorDesign.py
 """
+
 from pyomo.common.dependencies import pandas as pd
-from pyomo.environ import (
-    ConcreteModel,
-    Param,
-    Var,
-    PositiveReals,
-    Objective,
-    Constraint,
-    maximize,
-    SolverFactory,
-)
-
-
-def reactor_design_model(data):
+import pyomo.environ as pyo
+import pyomo.contrib.parmest.parmest as parmest
+from pyomo.contrib.parmest.experiment import Experiment
+
+
+def reactor_design_model():
+
     # Create the concrete model
-    model = ConcreteModel()
+    model = pyo.ConcreteModel()
 
     # Rate constants
-    model.k1 = Param(initialize=5.0 / 6.0, within=PositiveReals, mutable=True)  # min^-1
-    model.k2 = Param(initialize=5.0 / 3.0, within=PositiveReals, mutable=True)  # min^-1
-    model.k3 = Param(
-        initialize=1.0 / 6000.0, within=PositiveReals, mutable=True
+    model.k1 = pyo.Param(
+        initialize=5.0 / 6.0, within=pyo.PositiveReals, mutable=True
+    )  # min^-1
+    model.k2 = pyo.Param(
+        initialize=5.0 / 3.0, within=pyo.PositiveReals, mutable=True
+    )  # min^-1
+    model.k3 = pyo.Param(
+        initialize=1.0 / 6000.0, within=pyo.PositiveReals, mutable=True
     )  # m^3/(gmol min)
 
     # Inlet concentration of A, gmol/m^3
-    if isinstance(data, dict) or isinstance(data, pd.Series):
-        model.caf = Param(initialize=float(data["caf"]), within=PositiveReals)
-    elif isinstance(data, pd.DataFrame):
-        model.caf = Param(initialize=float(data.iloc[0]["caf"]), within=PositiveReals)
-    else:
-        raise ValueError("Unrecognized data type.")
+    model.caf = pyo.Param(initialize=10000, within=pyo.PositiveReals, mutable=True)
 
     # Space velocity (flowrate/volume)
-    if isinstance(data, dict) or isinstance(data, pd.Series):
-        model.sv = Param(initialize=float(data["sv"]), within=PositiveReals)
-    elif isinstance(data, pd.DataFrame):
-        model.sv = Param(initialize=float(data.iloc[0]["sv"]), within=PositiveReals)
-    else:
-        raise ValueError("Unrecognized data type.")
+    model.sv = pyo.Param(initialize=1.0, within=pyo.PositiveReals, mutable=True)
 
     # Outlet concentration of each component
-    model.ca = Var(initialize=5000.0, within=PositiveReals)
-    model.cb = Var(initialize=2000.0, within=PositiveReals)
-    model.cc = Var(initialize=2000.0, within=PositiveReals)
-    model.cd = Var(initialize=1000.0, within=PositiveReals)
+    model.ca = pyo.Var(initialize=5000.0, within=pyo.PositiveReals)
+    model.cb = pyo.Var(initialize=2000.0, within=pyo.PositiveReals)
+    model.cc = pyo.Var(initialize=2000.0, within=pyo.PositiveReals)
+    model.cd = pyo.Var(initialize=1000.0, within=pyo.PositiveReals)
 
     # Objective
-    model.obj = Objective(expr=model.cb, sense=maximize)
+    model.obj = pyo.Objective(expr=model.cb, sense=pyo.maximize)
 
     # Constraints
-    model.ca_bal = Constraint(
+    model.ca_bal = pyo.Constraint(
         expr=(
             0
             == model.sv * model.caf
@@ -72,28 +61,96 @@ def reactor_design_model(data):
         )
     )
 
-    model.cb_bal = Constraint(
+    model.cb_bal = pyo.Constraint(
         expr=(0 == -model.sv * model.cb + model.k1 * model.ca - model.k2 * model.cb)
     )
 
-    model.cc_bal = Constraint(expr=(0 == -model.sv * model.cc + model.k2 * model.cb))
+    model.cc_bal = pyo.Constraint(
+        expr=(0 == -model.sv * model.cc + model.k2 * model.cb)
+    )
 
-    model.cd_bal = Constraint(
+    model.cd_bal = pyo.Constraint(
         expr=(0 == -model.sv * model.cd + model.k3 * model.ca**2.0)
     )
 
     return model
 
 
+class ReactorDesignExperiment(Experiment):
+
+    def __init__(self, data, experiment_number):
+        self.data = data
+        self.experiment_number = experiment_number
+        self.data_i = data.loc[experiment_number, :]
+        self.model = None
+
+    def create_model(self):
+        self.model = m = reactor_design_model()
+        return m
+
+    def finalize_model(self):
+        m = self.model
+
+        # Experiment inputs values
+        m.sv = self.data_i['sv']
+        m.caf = self.data_i['caf']
+
+        # Experiment output values
+        m.ca = self.data_i['ca']
+        m.cb = self.data_i['cb']
+        m.cc = self.data_i['cc']
+        m.cd = self.data_i['cd']
+
+        return m
+
+    def label_model(self):
+        m = self.model
+
+        m.experiment_outputs = pyo.Suffix(direction=pyo.Suffix.LOCAL)
+        m.experiment_outputs.update(
+            [
+                (m.ca, self.data_i['ca']),
+                (m.cb, self.data_i['cb']),
+                (m.cc, self.data_i['cc']),
+                (m.cd, self.data_i['cd']),
+            ]
+        )
+
+        m.unknown_parameters = pyo.Suffix(direction=pyo.Suffix.LOCAL)
+        m.unknown_parameters.update(
+            (k, pyo.ComponentUID(k)) for k in [m.k1, m.k2, m.k3]
+        )
+
+        return m
+
+    def get_labeled_model(self):
+        m = self.create_model()
+        m = self.finalize_model()
+        m = self.label_model()
+
+        return m
+
+
 def main():
+
     # For a range of sv values, return ca, cb, cc, and cd
     results = []
     sv_values = [1.0 + v * 0.05 for v in range(1, 20)]
     caf = 10000
     for sv in sv_values:
-        model = reactor_design_model(pd.DataFrame(data={"caf": [caf], "sv": [sv]}))
-        solver = SolverFactory("ipopt")
+
+        # make model
+        model = reactor_design_model()
+
+        # add caf, sv
+        model.caf = caf
+        model.sv = sv
+
+        # solve model
+        solver = pyo.SolverFactory("ipopt")
         solver.solve(model)
+
+        # save results
         results.append([sv, caf, model.ca(), model.cb(), model.cc(), model.cd()])
 
     results = pd.DataFrame(results, columns=["sv", "caf", "ca", "cb", "cc", "cd"])
diff --git a/pyomo/contrib/parmest/examples/reactor_design/timeseries_data_example.py b/pyomo/contrib/parmest/examples/reactor_design/timeseries_data_example.py
index ff6c167f68d..4eb191afd6d 100644
--- a/pyomo/contrib/parmest/examples/reactor_design/timeseries_data_example.py
+++ b/pyomo/contrib/parmest/examples/reactor_design/timeseries_data_example.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -14,38 +14,64 @@
 
 import pyomo.contrib.parmest.parmest as parmest
 from pyomo.contrib.parmest.examples.reactor_design.reactor_design import (
-    reactor_design_model,
+    ReactorDesignExperiment,
 )
 
 
-def main():
-    # Parameter estimation using timeseries data
+class TimeSeriesReactorDesignExperiment(ReactorDesignExperiment):
+
+    def __init__(self, data, experiment_number):
+        self.data = data
+        self.experiment_number = experiment_number
+        data_i = data.loc[data['experiment'] == experiment_number, :]
+        self.data_i = data_i.reset_index()
+        self.model = None
+
+    def finalize_model(self):
+        m = self.model
+
+        # Experiment inputs values
+        m.sv = self.data_i['sv'].mean()
+        m.caf = self.data_i['caf'].mean()
+
+        # Experiment output values
+        m.ca = self.data_i['ca'][0]
+        m.cb = self.data_i['cb'][0]
+        m.cc = self.data_i['cc'][0]
+        m.cd = self.data_i['cd'][0]
+
+        return m
 
-    # Vars to estimate
-    theta_names = ['k1', 'k2', 'k3']
+
+def main():
+    # Parameter estimation using timeseries data, grouped by experiment number
 
     # Data, includes multiple sensors for ca and cc
     file_dirname = dirname(abspath(str(__file__)))
     file_name = abspath(join(file_dirname, 'reactor_data_timeseries.csv'))
     data = pd.read_csv(file_name)
 
-    # Group time series data into experiments, return the mean value for sv and caf
-    # Returns a list of dictionaries
-    data_ts = parmest.group_data(data, 'experiment', ['sv', 'caf'])
+    # Create an experiment list
+    exp_list = []
+    for i in data['experiment'].unique():
+        exp_list.append(TimeSeriesReactorDesignExperiment(data, i))
+
+    def SSE_timeseries(model):
 
-    def SSE_timeseries(model, data):
         expr = 0
-        for val in data['ca']:
-            expr = expr + ((float(val) - model.ca) ** 2) * (1 / len(data['ca']))
-        for val in data['cb']:
-            expr = expr + ((float(val) - model.cb) ** 2) * (1 / len(data['cb']))
-        for val in data['cc']:
-            expr = expr + ((float(val) - model.cc) ** 2) * (1 / len(data['cc']))
-        for val in data['cd']:
-            expr = expr + ((float(val) - model.cd) ** 2) * (1 / len(data['cd']))
+        for y, y_hat in model.experiment_outputs.items():
+            num_time_points = len(y_hat)
+            for i in range(num_time_points):
+                expr += ((y - y_hat[i]) ** 2) * (1 / num_time_points)
+
         return expr
 
-    pest = parmest.Estimator(reactor_design_model, data_ts, theta_names, SSE_timeseries)
+    # View one model & SSE
+    # exp0_model = exp_list[0].get_labeled_model()
+    # exp0_model.pprint()
+    # print(SSE_timeseries(exp0_model))
+
+    pest = parmest.Estimator(exp_list, obj_function=SSE_timeseries)
     obj, theta = pest.theta_est()
     print(obj)
     print(theta)
diff --git a/pyomo/contrib/parmest/examples/rooney_biegler/__init__.py b/pyomo/contrib/parmest/examples/rooney_biegler/__init__.py
index d93cfd77b3c..a4a626013c4 100644
--- a/pyomo/contrib/parmest/examples/rooney_biegler/__init__.py
+++ b/pyomo/contrib/parmest/examples/rooney_biegler/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/parmest/examples/rooney_biegler/bootstrap_example.py b/pyomo/contrib/parmest/examples/rooney_biegler/bootstrap_example.py
index 1c82adb909a..944a01ac95e 100644
--- a/pyomo/contrib/parmest/examples/rooney_biegler/bootstrap_example.py
+++ b/pyomo/contrib/parmest/examples/rooney_biegler/bootstrap_example.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -12,13 +12,11 @@
 from pyomo.common.dependencies import pandas as pd
 import pyomo.contrib.parmest.parmest as parmest
 from pyomo.contrib.parmest.examples.rooney_biegler.rooney_biegler import (
-    rooney_biegler_model,
+    RooneyBieglerExperiment,
 )
 
 
 def main():
-    # Vars to estimate
-    theta_names = ['asymptote', 'rate_constant']
 
     # Data
     data = pd.DataFrame(
@@ -27,14 +25,24 @@ def main():
     )
 
     # Sum of squared error function
-    def SSE(model, data):
-        expr = sum(
-            (data.y[i] - model.response_function[data.hour[i]]) ** 2 for i in data.index
-        )
+    def SSE(model):
+        expr = (
+            model.experiment_outputs[model.y]
+            - model.response_function[model.experiment_outputs[model.hour]]
+        ) ** 2
         return expr
 
+    # Create an experiment list
+    exp_list = []
+    for i in range(data.shape[0]):
+        exp_list.append(RooneyBieglerExperiment(data.loc[i, :]))
+
+    # View one model
+    # exp0_model = exp_list[0].get_labeled_model()
+    # exp0_model.pprint()
+
     # Create an instance of the parmest estimator
-    pest = parmest.Estimator(rooney_biegler_model, data, theta_names, SSE)
+    pest = parmest.Estimator(exp_list, obj_function=SSE)
 
     # Parameter estimation
     obj, theta = pest.theta_est()
diff --git a/pyomo/contrib/parmest/examples/rooney_biegler/likelihood_ratio_example.py b/pyomo/contrib/parmest/examples/rooney_biegler/likelihood_ratio_example.py
index 7cd77166a4b..54343993286 100644
--- a/pyomo/contrib/parmest/examples/rooney_biegler/likelihood_ratio_example.py
+++ b/pyomo/contrib/parmest/examples/rooney_biegler/likelihood_ratio_example.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -13,13 +13,11 @@
 from itertools import product
 import pyomo.contrib.parmest.parmest as parmest
 from pyomo.contrib.parmest.examples.rooney_biegler.rooney_biegler import (
-    rooney_biegler_model,
+    RooneyBieglerExperiment,
 )
 
 
 def main():
-    # Vars to estimate
-    theta_names = ['asymptote', 'rate_constant']
 
     # Data
     data = pd.DataFrame(
@@ -28,14 +26,24 @@ def main():
     )
 
     # Sum of squared error function
-    def SSE(model, data):
-        expr = sum(
-            (data.y[i] - model.response_function[data.hour[i]]) ** 2 for i in data.index
-        )
+    def SSE(model):
+        expr = (
+            model.experiment_outputs[model.y]
+            - model.response_function[model.experiment_outputs[model.hour]]
+        ) ** 2
         return expr
 
+    # Create an experiment list
+    exp_list = []
+    for i in range(data.shape[0]):
+        exp_list.append(RooneyBieglerExperiment(data.loc[i, :]))
+
+    # View one model
+    # exp0_model = exp_list[0].get_labeled_model()
+    # exp0_model.pprint()
+
     # Create an instance of the parmest estimator
-    pest = parmest.Estimator(rooney_biegler_model, data, theta_names, SSE)
+    pest = parmest.Estimator(exp_list, obj_function=SSE)
 
     # Parameter estimation
     obj, theta = pest.theta_est()
diff --git a/pyomo/contrib/parmest/examples/rooney_biegler/parameter_estimation_example.py b/pyomo/contrib/parmest/examples/rooney_biegler/parameter_estimation_example.py
index 9aa59be6a17..3c9a93100bb 100644
--- a/pyomo/contrib/parmest/examples/rooney_biegler/parameter_estimation_example.py
+++ b/pyomo/contrib/parmest/examples/rooney_biegler/parameter_estimation_example.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -12,13 +12,11 @@
 from pyomo.common.dependencies import pandas as pd
 import pyomo.contrib.parmest.parmest as parmest
 from pyomo.contrib.parmest.examples.rooney_biegler.rooney_biegler import (
-    rooney_biegler_model,
+    RooneyBieglerExperiment,
 )
 
 
 def main():
-    # Vars to estimate
-    theta_names = ['asymptote', 'rate_constant']
 
     # Data
     data = pd.DataFrame(
@@ -27,14 +25,24 @@ def main():
     )
 
     # Sum of squared error function
-    def SSE(model, data):
-        expr = sum(
-            (data.y[i] - model.response_function[data.hour[i]]) ** 2 for i in data.index
-        )
+    def SSE(model):
+        expr = (
+            model.experiment_outputs[model.y]
+            - model.response_function[model.experiment_outputs[model.hour]]
+        ) ** 2
         return expr
 
+    # Create an experiment list
+    exp_list = []
+    for i in range(data.shape[0]):
+        exp_list.append(RooneyBieglerExperiment(data.loc[i, :]))
+
+    # View one model
+    # exp0_model = exp_list[0].get_labeled_model()
+    # exp0_model.pprint()
+
     # Create an instance of the parmest estimator
-    pest = parmest.Estimator(rooney_biegler_model, data, theta_names, SSE)
+    pest = parmest.Estimator(exp_list, obj_function=SSE)
 
     # Parameter estimation and covariance
     n = 6  # total number of data points used in the objective (y in 6 scenarios)
diff --git a/pyomo/contrib/parmest/examples/rooney_biegler/rooney_biegler.py b/pyomo/contrib/parmest/examples/rooney_biegler/rooney_biegler.py
index 7a48dcf190d..9625ab32ea3 100644
--- a/pyomo/contrib/parmest/examples/rooney_biegler/rooney_biegler.py
+++ b/pyomo/contrib/parmest/examples/rooney_biegler/rooney_biegler.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -17,6 +17,7 @@
 
 from pyomo.common.dependencies import pandas as pd
 import pyomo.environ as pyo
+from pyomo.contrib.parmest.experiment import Experiment
 
 
 def rooney_biegler_model(data):
@@ -25,6 +26,9 @@ def rooney_biegler_model(data):
     model.asymptote = pyo.Var(initialize=15)
     model.rate_constant = pyo.Var(initialize=0.5)
 
+    model.hour = pyo.Param(within=pyo.PositiveReals, mutable=True)
+    model.y = pyo.Param(within=pyo.PositiveReals, mutable=True)
+
     def response_rule(m, h):
         expr = m.asymptote * (1 - pyo.exp(-m.rate_constant * h))
         return expr
@@ -41,6 +45,47 @@ def SSE_rule(m):
     return model
 
 
+class RooneyBieglerExperiment(Experiment):
+
+    def __init__(self, data):
+        self.data = data
+        self.model = None
+
+    def create_model(self):
+        # rooney_biegler_model expects a dataframe
+        data_df = self.data.to_frame().transpose()
+        self.model = rooney_biegler_model(data_df)
+
+    def label_model(self):
+
+        m = self.model
+
+        m.experiment_outputs = pyo.Suffix(direction=pyo.Suffix.LOCAL)
+        m.experiment_outputs.update(
+            [(m.hour, self.data['hour']), (m.y, self.data['y'])]
+        )
+
+        m.unknown_parameters = pyo.Suffix(direction=pyo.Suffix.LOCAL)
+        m.unknown_parameters.update(
+            (k, pyo.ComponentUID(k)) for k in [m.asymptote, m.rate_constant]
+        )
+
+    def finalize_model(self):
+
+        m = self.model
+
+        # Experiment output values
+        m.hour = self.data['hour']
+        m.y = self.data['y']
+
+    def get_labeled_model(self):
+        self.create_model()
+        self.label_model()
+        self.finalize_model()
+
+        return self.model
+
+
 def main():
     # These were taken from Table A1.4 in Bates and Watts (1988).
     data = pd.DataFrame(
diff --git a/pyomo/contrib/parmest/examples/rooney_biegler/rooney_biegler_with_constraint.py b/pyomo/contrib/parmest/examples/rooney_biegler/rooney_biegler_with_constraint.py
index 0ad65b1eb7a..dd82b50cf7a 100644
--- a/pyomo/contrib/parmest/examples/rooney_biegler/rooney_biegler_with_constraint.py
+++ b/pyomo/contrib/parmest/examples/rooney_biegler/rooney_biegler_with_constraint.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -17,6 +17,7 @@
 
 from pyomo.common.dependencies import pandas as pd
 import pyomo.environ as pyo
+from pyomo.contrib.parmest.experiment import Experiment
 
 
 def rooney_biegler_model_with_constraint(data):
@@ -24,6 +25,10 @@ def rooney_biegler_model_with_constraint(data):
 
     model.asymptote = pyo.Var(initialize=15)
     model.rate_constant = pyo.Var(initialize=0.5)
+
+    model.hour = pyo.Param(within=pyo.PositiveReals, mutable=True)
+    model.y = pyo.Param(within=pyo.PositiveReals, mutable=True)
+
     model.response_function = pyo.Var(data.hour, initialize=0.0)
 
     # changed from expression to constraint
@@ -44,6 +49,47 @@ def SSE_rule(m):
     return model
 
 
+class RooneyBieglerExperiment(Experiment):
+
+    def __init__(self, data):
+        self.data = data
+        self.model = None
+
+    def create_model(self):
+        # rooney_biegler_model_with_constraint expects a dataframe
+        data_df = self.data.to_frame().transpose()
+        self.model = rooney_biegler_model_with_constraint(data_df)
+
+    def label_model(self):
+
+        m = self.model
+
+        m.experiment_outputs = pyo.Suffix(direction=pyo.Suffix.LOCAL)
+        m.experiment_outputs.update(
+            [(m.hour, self.data['hour']), (m.y, self.data['y'])]
+        )
+
+        m.unknown_parameters = pyo.Suffix(direction=pyo.Suffix.LOCAL)
+        m.unknown_parameters.update(
+            (k, pyo.ComponentUID(k)) for k in [m.asymptote, m.rate_constant]
+        )
+
+    def finalize_model(self):
+
+        m = self.model
+
+        # Experiment output values
+        m.hour = self.data['hour']
+        m.y = self.data['y']
+
+    def get_labeled_model(self):
+        self.create_model()
+        self.label_model()
+        self.finalize_model()
+
+        return self.model
+
+
 def main():
     # These were taken from Table A1.4 in Bates and Watts (1988).
     data = pd.DataFrame(
diff --git a/pyomo/contrib/parmest/examples/semibatch/__init__.py b/pyomo/contrib/parmest/examples/semibatch/__init__.py
index d93cfd77b3c..a4a626013c4 100644
--- a/pyomo/contrib/parmest/examples/semibatch/__init__.py
+++ b/pyomo/contrib/parmest/examples/semibatch/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/parmest/examples/semibatch/parallel_example.py b/pyomo/contrib/parmest/examples/semibatch/parallel_example.py
index ba69b9f2d06..d7cc497803e 100644
--- a/pyomo/contrib/parmest/examples/semibatch/parallel_example.py
+++ b/pyomo/contrib/parmest/examples/semibatch/parallel_example.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/parmest/examples/semibatch/parameter_estimation_example.py b/pyomo/contrib/parmest/examples/semibatch/parameter_estimation_example.py
index fc4c9f5c675..7eafdd2b9c3 100644
--- a/pyomo/contrib/parmest/examples/semibatch/parameter_estimation_example.py
+++ b/pyomo/contrib/parmest/examples/semibatch/parameter_estimation_example.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -12,12 +12,10 @@
 import json
 from os.path import join, abspath, dirname
 import pyomo.contrib.parmest.parmest as parmest
-from pyomo.contrib.parmest.examples.semibatch.semibatch import generate_model
+from pyomo.contrib.parmest.examples.semibatch.semibatch import SemiBatchExperiment
 
 
 def main():
-    # Vars to estimate
-    theta_names = ['k1', 'k2', 'E1', 'E2']
 
     # Data, list of dictionaries
     data = []
@@ -28,10 +26,19 @@ def main():
             d = json.load(infile)
             data.append(d)
 
+    # Create an experiment list
+    exp_list = []
+    for i in range(len(data)):
+        exp_list.append(SemiBatchExperiment(data[i]))
+
+    # View one model
+    # exp0_model = exp_list[0].get_labeled_model()
+    # exp0_model.pprint()
+
     # Note, the model already includes a 'SecondStageCost' expression
     # for sum of squared error that will be used in parameter estimation
 
-    pest = parmest.Estimator(generate_model, data, theta_names)
+    pest = parmest.Estimator(exp_list)
 
     obj, theta = pest.theta_est()
     print(obj)
diff --git a/pyomo/contrib/parmest/examples/semibatch/scenario_example.py b/pyomo/contrib/parmest/examples/semibatch/scenario_example.py
index 071e53236c4..697cb9ac7a5 100644
--- a/pyomo/contrib/parmest/examples/semibatch/scenario_example.py
+++ b/pyomo/contrib/parmest/examples/semibatch/scenario_example.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -12,13 +12,11 @@
 import json
 from os.path import join, abspath, dirname
 import pyomo.contrib.parmest.parmest as parmest
-from pyomo.contrib.parmest.examples.semibatch.semibatch import generate_model
+from pyomo.contrib.parmest.examples.semibatch.semibatch import SemiBatchExperiment
 import pyomo.contrib.parmest.scenariocreator as sc
 
 
 def main():
-    # Vars to estimate in parmest
-    theta_names = ['k1', 'k2', 'E1', 'E2']
 
     # Data: list of dictionaries
     data = []
@@ -29,7 +27,16 @@ def main():
             d = json.load(infile)
             data.append(d)
 
-    pest = parmest.Estimator(generate_model, data, theta_names)
+    # Create an experiment list
+    exp_list = []
+    for i in range(len(data)):
+        exp_list.append(SemiBatchExperiment(data[i]))
+
+    # View one model
+    # exp0_model = exp_list[0].get_labeled_model()
+    # exp0_model.pprint()
+
+    pest = parmest.Estimator(exp_list)
 
     scenmaker = sc.ScenarioCreator(pest, "ipopt")
 
diff --git a/pyomo/contrib/parmest/examples/semibatch/semibatch.py b/pyomo/contrib/parmest/examples/semibatch/semibatch.py
index 6762531a338..b506d41d072 100644
--- a/pyomo/contrib/parmest/examples/semibatch/semibatch.py
+++ b/pyomo/contrib/parmest/examples/semibatch/semibatch.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -29,8 +29,11 @@
     SolverFactory,
     exp,
     minimize,
+    Suffix,
+    ComponentUID,
 )
 from pyomo.dae import ContinuousSet, DerivativeVar
+from pyomo.contrib.parmest.experiment import Experiment
 
 
 def generate_model(data):
@@ -268,6 +271,35 @@ def total_cost_rule(model):
     return m
 
 
+class SemiBatchExperiment(Experiment):
+
+    def __init__(self, data):
+        self.data = data
+        self.model = None
+
+    def create_model(self):
+        self.model = generate_model(self.data)
+
+    def label_model(self):
+
+        m = self.model
+
+        m.unknown_parameters = Suffix(direction=Suffix.LOCAL)
+        m.unknown_parameters.update(
+            (k, ComponentUID(k)) for k in [m.k1, m.k2, m.E1, m.E2]
+        )
+
+    def finalize_model(self):
+        pass
+
+    def get_labeled_model(self):
+        self.create_model()
+        self.label_model()
+        self.finalize_model()
+
+        return self.model
+
+
 def main():
     # Data loaded from files
     file_dirname = dirname(abspath(str(__file__)))
diff --git a/pyomo/contrib/parmest/experiment.py b/pyomo/contrib/parmest/experiment.py
new file mode 100644
index 00000000000..4f797d6c89c
--- /dev/null
+++ b/pyomo/contrib/parmest/experiment.py
@@ -0,0 +1,31 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+
+class Experiment:
+    """
+    The experiment class is a template for making experiment lists
+    to pass to parmest.
+
+    An experiment is a Pyomo model "m" which is labeled
+    with additional suffixes:
+    * m.experiment_outputs which defines experiment outputs
+    * m.unknown_parameters which defines parameters to estimate
+
+    The experiment class has one required method:
+    * get_labeled_model() which returns the labeled Pyomo model
+    """
+
+    def __init__(self, model=None):
+        self.model = model
+
+    def get_labeled_model(self):
+        return self.model
diff --git a/pyomo/contrib/parmest/graphics.py b/pyomo/contrib/parmest/graphics.py
index 65efb5cfd64..c57bfb19696 100644
--- a/pyomo/contrib/parmest/graphics.py
+++ b/pyomo/contrib/parmest/graphics.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/parmest/ipopt_solver_wrapper.py b/pyomo/contrib/parmest/ipopt_solver_wrapper.py
index a6d5e0506fb..75c470a4b81 100644
--- a/pyomo/contrib/parmest/ipopt_solver_wrapper.py
+++ b/pyomo/contrib/parmest/ipopt_solver_wrapper.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/parmest/parmest.py b/pyomo/contrib/parmest/parmest.py
index 82bf893dd06..41e7792570b 100644
--- a/pyomo/contrib/parmest/parmest.py
+++ b/pyomo/contrib/parmest/parmest.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -11,9 +11,9 @@
 #### Using mpi-sppy instead of PySP; May 2020
 #### Adding option for "local" EF starting Sept 2020
 #### Wrapping mpi-sppy functionality and local option Jan 2021, Feb 2021
+#### Redesign with Experiment class Dec 2023
 
 # TODO: move use_mpisppy to a Pyomo configuration option
-#
 # False implies always use the EF that is local to parmest
 use_mpisppy = True  # Use it if we can but use local if not.
 if use_mpisppy:
@@ -42,7 +42,9 @@
 import logging
 import types
 import json
+from collections.abc import Callable
 from itertools import combinations
+from functools import singledispatchmethod
 
 from pyomo.common.dependencies import (
     attempt_import,
@@ -63,6 +65,9 @@
 import pyomo.contrib.parmest.graphics as graphics
 from pyomo.dae import ContinuousSet
 
+from pyomo.common.deprecation import deprecated
+from pyomo.common.deprecation import deprecation_warning
+
 parmest_available = numpy_available & pandas_available & scipy_available
 
 inverse_reduced_hessian, inverse_reduced_hessian_available = attempt_import(
@@ -209,12 +214,12 @@ def _experiment_instance_creation_callback(
         thetavals = outer_cb_data["ThetaVals"]
 
         # dlw august 2018: see mea code for more general theta
-        for vstr in thetavals:
-            theta_cuid = ComponentUID(vstr)
+        for name, val in thetavals.items():
+            theta_cuid = ComponentUID(name)
             theta_object = theta_cuid.find_component_on(instance)
-            if thetavals[vstr] is not None:
+            if val is not None:
                 # print("Fixing",vstr,"at",str(thetavals[vstr]))
-                theta_object.fix(thetavals[vstr])
+                theta_object.fix(val)
             else:
                 # print("Freeing",vstr)
                 theta_object.unfix()
@@ -222,93 +227,1215 @@ def _experiment_instance_creation_callback(
     return instance
 
 
-# =============================================
-def _treemaker(scenlist):
+def SSE(model):
+    """
+    Sum of squared error between `experiment_output` model and data values
+    """
+    expr = sum((y - y_hat) ** 2 for y, y_hat in model.experiment_outputs.items())
+    return expr
+
+
+class Estimator(object):
     """
-    Makes a scenario tree (avoids dependence on daps)
+    Parameter estimation class
 
     Parameters
     ----------
-    scenlist (list of `int`): experiment (i.e. scenario) numbers
-
-    Returns
-    -------
-    a `ConcreteModel` that is the scenario tree
+    experiment_list: list of Experiments
+        A list of experiment objects which creates one labeled model for
+        each experiment
+    obj_function: string or function (optional)
+        Built in objective (currently only "SSE") or custom function used to
+        formulate parameter estimation objective.
+        If no function is specified, the model is used
+        "as is" and should be defined with a "FirstStageCost" and
+        "SecondStageCost" expression that are used to build an objective.
+        Default is None.
+    tee: bool, optional
+        If True, print the solver output to the screen. Default is False.
+    diagnostic_mode: bool, optional
+        If True, print diagnostics from the solver. Default is False.
+    solver_options: dict, optional
+        Provides options to the solver (also the name of an attribute).
+        Default is None.
     """
 
-    num_scenarios = len(scenlist)
-    m = scenario_tree.tree_structure_model.CreateAbstractScenarioTreeModel()
-    m = m.create_instance()
-    m.Stages.add('Stage1')
-    m.Stages.add('Stage2')
-    m.Nodes.add('RootNode')
-    for i in scenlist:
-        m.Nodes.add('LeafNode_Experiment' + str(i))
-        m.Scenarios.add('Experiment' + str(i))
-    m.NodeStage['RootNode'] = 'Stage1'
-    m.ConditionalProbability['RootNode'] = 1.0
-    for node in m.Nodes:
-        if node != 'RootNode':
-            m.NodeStage[node] = 'Stage2'
-            m.Children['RootNode'].add(node)
-            m.Children[node].clear()
-            m.ConditionalProbability[node] = 1.0 / num_scenarios
-            m.ScenarioLeafNode[node.replace('LeafNode_', '')] = node
-
-    return m
+    # The singledispatchmethod decorator is used here as a deprecation
+    # shim to be able to support the now deprecated Estimator interface
+    # which had a different number of arguments. When the deprecated API
+    # is removed this decorator and the _deprecated_init method below
+    # can be removed
+    @singledispatchmethod
+    def __init__(
+        self,
+        experiment_list,
+        obj_function=None,
+        tee=False,
+        diagnostic_mode=False,
+        solver_options=None,
+    ):
 
+        # check that we have a (non-empty) list of experiments
+        assert isinstance(experiment_list, list)
+        self.exp_list = experiment_list
 
-def group_data(data, groupby_column_name, use_mean=None):
-    """
-    Group data by scenario
+        # check that an experiment has experiment_outputs and unknown_parameters
+        model = self.exp_list[0].get_labeled_model()
+        try:
+            outputs = [k.name for k, v in model.experiment_outputs.items()]
+        except:
+            RuntimeError(
+                'Experiment list model does not have suffix ' + '"experiment_outputs".'
+            )
+        try:
+            params = [k.name for k, v in model.unknown_parameters.items()]
+        except:
+            RuntimeError(
+                'Experiment list model does not have suffix ' + '"unknown_parameters".'
+            )
 
-    Parameters
-    ----------
-    data: DataFrame
-        Data
-    groupby_column_name: strings
-        Name of data column which contains scenario numbers
-    use_mean: list of column names or None, optional
-        Name of data columns which should be reduced to a single value per
-        scenario by taking the mean
+        # populate keyword argument options
+        self.obj_function = obj_function
+        self.tee = tee
+        self.diagnostic_mode = diagnostic_mode
+        self.solver_options = solver_options
 
-    Returns
-    ----------
-    grouped_data: list of dictionaries
-        Grouped data
-    """
-    if use_mean is None:
-        use_mean_list = []
-    else:
-        use_mean_list = use_mean
+        # TODO: delete this when the deprecated interface is removed
+        self.pest_deprecated = None
+
+        # TODO This might not be needed here.
+        # We could collect the union (or intersect?) of thetas when the models are built
+        theta_names = []
+        for experiment in self.exp_list:
+            model = experiment.get_labeled_model()
+            theta_names.extend([k.name for k, v in model.unknown_parameters.items()])
+        self.estimator_theta_names = list(set(theta_names))
+
+        self._second_stage_cost_exp = "SecondStageCost"
+        # boolean to indicate if model is initialized using a square solve
+        self.model_initialized = False
+
+    # The deprecated Estimator constructor
+    # This works by checking the type of the first argument passed to
+    # the class constructor. If it matches the old interface (i.e. is
+    # callable) then this _deprecated_init method is called and the
+    # deprecation warning is displayed.
+    @__init__.register(Callable)
+    def _deprecated_init(
+        self,
+        model_function,
+        data,
+        theta_names,
+        obj_function=None,
+        tee=False,
+        diagnostic_mode=False,
+        solver_options=None,
+    ):
+
+        deprecation_warning(
+            "You're using the deprecated parmest interface (model_function, "
+            "data, theta_names). This interface will be removed in a future release, "
+            "please update to the new parmest interface using experiment lists.",
+            version='6.7.2',
+        )
+        self.pest_deprecated = _DeprecatedEstimator(
+            model_function,
+            data,
+            theta_names,
+            obj_function,
+            tee,
+            diagnostic_mode,
+            solver_options,
+        )
+
+    def _return_theta_names(self):
+        """
+        Return list of fitted model parameter names
+        """
+        # check for deprecated inputs
+        if self.pest_deprecated:
+
+            # if fitted model parameter names differ from theta_names
+            # created when Estimator object is created
+            if hasattr(self, 'theta_names_updated'):
+                return self.pest_deprecated.theta_names_updated
 
-    grouped_data = []
-    for exp_num, group in data.groupby(data[groupby_column_name]):
-        d = {}
-        for col in group.columns:
-            if col in use_mean_list:
-                d[col] = group[col].mean()
             else:
-                d[col] = list(group[col])
-        grouped_data.append(d)
 
-    return grouped_data
+                # default theta_names, created when Estimator object is created
+                return self.pest_deprecated.theta_names
 
+        else:
 
-class _SecondStageCostExpr(object):
-    """
-    Class to pass objective expression into the Pyomo model
-    """
+            # if fitted model parameter names differ from theta_names
+            # created when Estimator object is created
+            if hasattr(self, 'theta_names_updated'):
+                return self.theta_names_updated
 
-    def __init__(self, ssc_function, data):
-        self._ssc_function = ssc_function
-        self._data = data
+            else:
 
-    def __call__(self, model):
-        return self._ssc_function(model, self._data)
+                # default theta_names, created when Estimator object is created
+                return self.estimator_theta_names
 
+    def _expand_indexed_unknowns(self, model_temp):
+        """
+        Expand indexed variables to get full list of thetas
+        """
 
-class Estimator(object):
+        model_theta_list = []
+        for c in model_temp.unknown_parameters.keys():
+            if c.is_indexed():
+                for _, ci in c.items():
+                    model_theta_list.append(ci.name)
+            else:
+                model_theta_list.append(c.name)
+
+        return model_theta_list
+
+    def _create_parmest_model(self, experiment_number):
+        """
+        Modify the Pyomo model for parameter estimation
+        """
+
+        model = self.exp_list[experiment_number].get_labeled_model()
+
+        if len(model.unknown_parameters) == 0:
+            model.parmest_dummy_var = pyo.Var(initialize=1.0)
+
+        # Add objective function (optional)
+        if self.obj_function:
+
+            # Check for component naming conflicts
+            reserved_names = [
+                'Total_Cost_Objective',
+                'FirstStageCost',
+                'SecondStageCost',
+            ]
+            for n in reserved_names:
+                if model.component(n) or hasattr(model, n):
+                    raise RuntimeError(
+                        f"Parmest will not override the existing model component named {n}"
+                    )
+
+            # Deactivate any existing objective functions
+            for obj in model.component_objects(pyo.Objective):
+                obj.deactivate()
+
+            # TODO, this needs to be turned into an enum class of options that still support
+            # custom functions
+            if self.obj_function == 'SSE':
+                second_stage_rule = SSE
+            else:
+                # A custom function uses model.experiment_outputs as data
+                second_stage_rule = self.obj_function
+
+            model.FirstStageCost = pyo.Expression(expr=0)
+            model.SecondStageCost = pyo.Expression(rule=second_stage_rule)
+
+            def TotalCost_rule(model):
+                return model.FirstStageCost + model.SecondStageCost
+
+            model.Total_Cost_Objective = pyo.Objective(
+                rule=TotalCost_rule, sense=pyo.minimize
+            )
+
+        # Convert theta Params to Vars, and unfix theta Vars
+        theta_names = [k.name for k, v in model.unknown_parameters.items()]
+        parmest_model = utils.convert_params_to_vars(model, theta_names, fix_vars=False)
+
+        return parmest_model
+
+    def _instance_creation_callback(self, experiment_number=None, cb_data=None):
+        model = self._create_parmest_model(experiment_number)
+        return model
+
+    def _Q_opt(
+        self,
+        ThetaVals=None,
+        solver="ef_ipopt",
+        return_values=[],
+        bootlist=None,
+        calc_cov=False,
+        cov_n=None,
+    ):
+        """
+        Set up all thetas as first stage Vars, return resulting theta
+        values as well as the objective function value.
+
+        """
+        if solver == "k_aug":
+            raise RuntimeError("k_aug no longer supported.")
+
+        # (Bootstrap scenarios will use indirection through the bootlist)
+        if bootlist is None:
+            scenario_numbers = list(range(len(self.exp_list)))
+            scen_names = ["Scenario{}".format(i) for i in scenario_numbers]
+        else:
+            scen_names = ["Scenario{}".format(i) for i in range(len(bootlist))]
+
+        # tree_model.CallbackModule = None
+        outer_cb_data = dict()
+        outer_cb_data["callback"] = self._instance_creation_callback
+        if ThetaVals is not None:
+            outer_cb_data["ThetaVals"] = ThetaVals
+        if bootlist is not None:
+            outer_cb_data["BootList"] = bootlist
+        outer_cb_data["cb_data"] = None  # None is OK
+        outer_cb_data["theta_names"] = self.estimator_theta_names
+
+        options = {"solver": "ipopt"}
+        scenario_creator_options = {"cb_data": outer_cb_data}
+        if use_mpisppy:
+            ef = sputils.create_EF(
+                scen_names,
+                _experiment_instance_creation_callback,
+                EF_name="_Q_opt",
+                suppress_warnings=True,
+                scenario_creator_kwargs=scenario_creator_options,
+            )
+        else:
+            ef = local_ef.create_EF(
+                scen_names,
+                _experiment_instance_creation_callback,
+                EF_name="_Q_opt",
+                suppress_warnings=True,
+                scenario_creator_kwargs=scenario_creator_options,
+            )
+        self.ef_instance = ef
+
+        # Solve the extensive form with ipopt
+        if solver == "ef_ipopt":
+            if not calc_cov:
+                # Do not calculate the reduced hessian
+
+                solver = SolverFactory('ipopt')
+                if self.solver_options is not None:
+                    for key in self.solver_options:
+                        solver.options[key] = self.solver_options[key]
+
+                solve_result = solver.solve(self.ef_instance, tee=self.tee)
+
+            # The import error will be raised when we attempt to use
+            # inv_reduced_hessian_barrier below.
+            #
+            # elif not asl_available:
+            #    raise ImportError("parmest requires ASL to calculate the "
+            #                      "covariance matrix with solver 'ipopt'")
+            else:
+                # parmest makes the fitted parameters stage 1 variables
+                ind_vars = []
+                for ndname, Var, solval in ef_nonants(ef):
+                    ind_vars.append(Var)
+                # calculate the reduced hessian
+                (solve_result, inv_red_hes) = (
+                    inverse_reduced_hessian.inv_reduced_hessian_barrier(
+                        self.ef_instance,
+                        independent_variables=ind_vars,
+                        solver_options=self.solver_options,
+                        tee=self.tee,
+                    )
+                )
+
+            if self.diagnostic_mode:
+                print(
+                    '    Solver termination condition = ',
+                    str(solve_result.solver.termination_condition),
+                )
+
+            # assume all first stage are thetas...
+            thetavals = {}
+            for ndname, Var, solval in ef_nonants(ef):
+                # process the name
+                # the scenarios are blocks, so strip the scenario name
+                vname = Var.name[Var.name.find(".") + 1 :]
+                thetavals[vname] = solval
+
+            objval = pyo.value(ef.EF_Obj)
+
+            if calc_cov:
+                # Calculate the covariance matrix
+
+                # Number of data points considered
+                n = cov_n
+
+                # Extract number of fitted parameters
+                l = len(thetavals)
+
+                # Assumption: Objective value is sum of squared errors
+                sse = objval
+
+                '''Calculate covariance assuming experimental observation errors are
+                independent and follow a Gaussian
+                distribution with constant variance.
+
+                The formula used in parmest was verified against equations (7-5-15) and
+                (7-5-16) in "Nonlinear Parameter Estimation", Y. Bard, 1974.
+
+                This formula is also applicable if the objective is scaled by a constant;
+                the constant cancels out. (was scaled by 1/n because it computes an
+                expected value.)
+                '''
+                cov = 2 * sse / (n - l) * inv_red_hes
+                cov = pd.DataFrame(
+                    cov, index=thetavals.keys(), columns=thetavals.keys()
+                )
+
+            thetavals = pd.Series(thetavals)
+
+            if len(return_values) > 0:
+                var_values = []
+                if len(scen_names) > 1:  # multiple scenarios
+                    block_objects = self.ef_instance.component_objects(
+                        Block, descend_into=False
+                    )
+                else:  # single scenario
+                    block_objects = [self.ef_instance]
+                for exp_i in block_objects:
+                    vals = {}
+                    for var in return_values:
+                        exp_i_var = exp_i.find_component(str(var))
+                        if (
+                            exp_i_var is None
+                        ):  # we might have a block such as _mpisppy_data
+                            continue
+                        # if value to return is ContinuousSet
+                        if type(exp_i_var) == ContinuousSet:
+                            temp = list(exp_i_var)
+                        else:
+                            temp = [pyo.value(_) for _ in exp_i_var.values()]
+                        if len(temp) == 1:
+                            vals[var] = temp[0]
+                        else:
+                            vals[var] = temp
+                    if len(vals) > 0:
+                        var_values.append(vals)
+                var_values = pd.DataFrame(var_values)
+                if calc_cov:
+                    return objval, thetavals, var_values, cov
+                else:
+                    return objval, thetavals, var_values
+
+            if calc_cov:
+                return objval, thetavals, cov
+            else:
+                return objval, thetavals
+
+        else:
+            raise RuntimeError("Unknown solver in Q_Opt=" + solver)
+
+    def _Q_at_theta(self, thetavals, initialize_parmest_model=False):
+        """
+        Return the objective function value with fixed theta values.
+
+        Parameters
+        ----------
+        thetavals: dict
+            A dictionary of theta values.
+
+        initialize_parmest_model: boolean
+            If True: Solve square problem instance, build extensive form of the model for
+            parameter estimation, and set flag model_initialized to True. Default is False.
+
+        Returns
+        -------
+        objectiveval: float
+            The objective function value.
+        thetavals: dict
+            A dictionary of all values for theta that were input.
+        solvertermination: Pyomo TerminationCondition
+            Tries to return the "worst" solver status across the scenarios.
+            pyo.TerminationCondition.optimal is the best and
+            pyo.TerminationCondition.infeasible is the worst.
+        """
+
+        optimizer = pyo.SolverFactory('ipopt')
+
+        if len(thetavals) > 0:
+            dummy_cb = {
+                "callback": self._instance_creation_callback,
+                "ThetaVals": thetavals,
+                "theta_names": self._return_theta_names(),
+                "cb_data": None,
+            }
+        else:
+            dummy_cb = {
+                "callback": self._instance_creation_callback,
+                "theta_names": self._return_theta_names(),
+                "cb_data": None,
+            }
+
+        if self.diagnostic_mode:
+            if len(thetavals) > 0:
+                print('    Compute objective at theta = ', str(thetavals))
+            else:
+                print('    Compute objective at initial theta')
+
+        # start block of code to deal with models with no constraints
+        # (ipopt will crash or complain on such problems without special care)
+        instance = _experiment_instance_creation_callback("FOO0", None, dummy_cb)
+        try:  # deal with special problems so Ipopt will not crash
+            first = next(instance.component_objects(pyo.Constraint, active=True))
+            active_constraints = True
+        except:
+            active_constraints = False
+        # end block of code to deal with models with no constraints
+
+        WorstStatus = pyo.TerminationCondition.optimal
+        totobj = 0
+        scenario_numbers = list(range(len(self.exp_list)))
+        if initialize_parmest_model:
+            # create dictionary to store pyomo model instances (scenarios)
+            scen_dict = dict()
+
+        for snum in scenario_numbers:
+            sname = "scenario_NODE" + str(snum)
+            instance = _experiment_instance_creation_callback(sname, None, dummy_cb)
+            model_theta_names = self._expand_indexed_unknowns(instance)
+
+            if initialize_parmest_model:
+                # list to store fitted parameter names that will be unfixed
+                # after initialization
+                theta_init_vals = []
+                # use appropriate theta_names member
+                theta_ref = model_theta_names
+
+                for i, theta in enumerate(theta_ref):
+                    # Use parser in ComponentUID to locate the component
+                    var_cuid = ComponentUID(theta)
+                    var_validate = var_cuid.find_component_on(instance)
+                    if var_validate is None:
+                        logger.warning(
+                            "theta_name %s was not found on the model", (theta)
+                        )
+                    else:
+                        try:
+                            if len(thetavals) == 0:
+                                var_validate.fix()
+                            else:
+                                var_validate.fix(thetavals[theta])
+                            theta_init_vals.append(var_validate)
+                        except:
+                            logger.warning(
+                                'Unable to fix model parameter value for %s (not a Pyomo model Var)',
+                                (theta),
+                            )
+
+            if active_constraints:
+                if self.diagnostic_mode:
+                    print('      Experiment = ', snum)
+                    print('     First solve with special diagnostics wrapper')
+                    (status_obj, solved, iters, time, regu) = (
+                        utils.ipopt_solve_with_stats(
+                            instance, optimizer, max_iter=500, max_cpu_time=120
+                        )
+                    )
+                    print(
+                        "   status_obj, solved, iters, time, regularization_stat = ",
+                        str(status_obj),
+                        str(solved),
+                        str(iters),
+                        str(time),
+                        str(regu),
+                    )
+
+                results = optimizer.solve(instance)
+                if self.diagnostic_mode:
+                    print(
+                        'standard solve solver termination condition=',
+                        str(results.solver.termination_condition),
+                    )
+
+                if (
+                    results.solver.termination_condition
+                    != pyo.TerminationCondition.optimal
+                ):
+                    # DLW: Aug2018: not distinguishing "middlish" conditions
+                    if WorstStatus != pyo.TerminationCondition.infeasible:
+                        WorstStatus = results.solver.termination_condition
+                    if initialize_parmest_model:
+                        if self.diagnostic_mode:
+                            print(
+                                "Scenario {:d} infeasible with initialized parameter values".format(
+                                    snum
+                                )
+                            )
+                else:
+                    if initialize_parmest_model:
+                        if self.diagnostic_mode:
+                            print(
+                                "Scenario {:d} initialization successful with initial parameter values".format(
+                                    snum
+                                )
+                            )
+                if initialize_parmest_model:
+                    # unfix parameters after initialization
+                    for theta in theta_init_vals:
+                        theta.unfix()
+                    scen_dict[sname] = instance
+            else:
+                if initialize_parmest_model:
+                    # unfix parameters after initialization
+                    for theta in theta_init_vals:
+                        theta.unfix()
+                    scen_dict[sname] = instance
+
+            objobject = getattr(instance, self._second_stage_cost_exp)
+            objval = pyo.value(objobject)
+            totobj += objval
+
+        retval = totobj / len(scenario_numbers)  # -1??
+        if initialize_parmest_model and not hasattr(self, 'ef_instance'):
+            # create extensive form of the model using scenario dictionary
+            if len(scen_dict) > 0:
+                for scen in scen_dict.values():
+                    scen._mpisppy_probability = 1 / len(scen_dict)
+
+            if use_mpisppy:
+                EF_instance = sputils._create_EF_from_scen_dict(
+                    scen_dict,
+                    EF_name="_Q_at_theta",
+                    # suppress_warnings=True
+                )
+            else:
+                EF_instance = local_ef._create_EF_from_scen_dict(
+                    scen_dict, EF_name="_Q_at_theta", nonant_for_fixed_vars=True
+                )
+
+            self.ef_instance = EF_instance
+            # set self.model_initialized flag to True to skip extensive form model
+            # creation using theta_est()
+            self.model_initialized = True
+
+            # return initialized theta values
+            if len(thetavals) == 0:
+                # use appropriate theta_names member
+                theta_ref = self._return_theta_names()
+                for i, theta in enumerate(theta_ref):
+                    thetavals[theta] = theta_init_vals[i]()
+
+        return retval, thetavals, WorstStatus
+
+    def _get_sample_list(self, samplesize, num_samples, replacement=True):
+        samplelist = list()
+
+        scenario_numbers = list(range(len(self.exp_list)))
+
+        if num_samples is None:
+            # This could get very large
+            for i, l in enumerate(combinations(scenario_numbers, samplesize)):
+                samplelist.append((i, np.sort(l)))
+        else:
+            for i in range(num_samples):
+                attempts = 0
+                unique_samples = 0  # check for duplicates in each sample
+                duplicate = False  # check for duplicates between samples
+                while (unique_samples <= len(self._return_theta_names())) and (
+                    not duplicate
+                ):
+                    sample = np.random.choice(
+                        scenario_numbers, samplesize, replace=replacement
+                    )
+                    sample = np.sort(sample).tolist()
+                    unique_samples = len(np.unique(sample))
+                    if sample in samplelist:
+                        duplicate = True
+
+                    attempts += 1
+                    if attempts > num_samples:  # arbitrary timeout limit
+                        raise RuntimeError(
+                            """Internal error: timeout constructing
+                                           a sample, the dim of theta may be too
+                                           close to the samplesize"""
+                        )
+
+                samplelist.append((i, sample))
+
+        return samplelist
+
+    def theta_est(
+        self, solver="ef_ipopt", return_values=[], calc_cov=False, cov_n=None
+    ):
+        """
+        Parameter estimation using all scenarios in the data
+
+        Parameters
+        ----------
+        solver: string, optional
+            Currently only "ef_ipopt" is supported. Default is "ef_ipopt".
+        return_values: list, optional
+            List of Variable names, used to return values from the model for data reconciliation
+        calc_cov: boolean, optional
+            If True, calculate and return the covariance matrix (only for "ef_ipopt" solver).
+            Default is False.
+        cov_n: int, optional
+            If calc_cov=True, then the user needs to supply the number of datapoints
+            that are used in the objective function.
+
+        Returns
+        -------
+        objectiveval: float
+            The objective function value
+        thetavals: pd.Series
+            Estimated values for theta
+        variable values: pd.DataFrame
+            Variable values for each variable name in return_values (only for solver='ef_ipopt')
+        cov: pd.DataFrame
+            Covariance matrix of the fitted parameters (only for solver='ef_ipopt')
+        """
+
+        # check if we are using deprecated parmest
+        if self.pest_deprecated is not None:
+            return self.pest_deprecated.theta_est(
+                solver=solver,
+                return_values=return_values,
+                calc_cov=calc_cov,
+                cov_n=cov_n,
+            )
+
+        assert isinstance(solver, str)
+        assert isinstance(return_values, list)
+        assert isinstance(calc_cov, bool)
+        if calc_cov:
+            num_unknowns = max(
+                [
+                    len(experiment.get_labeled_model().unknown_parameters)
+                    for experiment in self.exp_list
+                ]
+            )
+            assert isinstance(cov_n, int), (
+                "The number of datapoints that are used in the objective function is "
+                "required to calculate the covariance matrix"
+            )
+            assert (
+                cov_n > num_unknowns
+            ), "The number of datapoints must be greater than the number of parameters to estimate"
+
+        return self._Q_opt(
+            solver=solver,
+            return_values=return_values,
+            bootlist=None,
+            calc_cov=calc_cov,
+            cov_n=cov_n,
+        )
+
+    def theta_est_bootstrap(
+        self,
+        bootstrap_samples,
+        samplesize=None,
+        replacement=True,
+        seed=None,
+        return_samples=False,
+    ):
+        """
+        Parameter estimation using bootstrap resampling of the data
+
+        Parameters
+        ----------
+        bootstrap_samples: int
+            Number of bootstrap samples to draw from the data
+        samplesize: int or None, optional
+            Size of each bootstrap sample. If samplesize=None, samplesize will be
+            set to the number of samples in the data
+        replacement: bool, optional
+            Sample with or without replacement. Default is True.
+        seed: int or None, optional
+            Random seed
+        return_samples: bool, optional
+            Return a list of sample numbers used in each bootstrap estimation.
+            Default is False.
+
+        Returns
+        -------
+        bootstrap_theta: pd.DataFrame
+            Theta values for each sample and (if return_samples = True)
+            the sample numbers used in each estimation
+        """
+
+        # check if we are using deprecated parmest
+        if self.pest_deprecated is not None:
+            return self.pest_deprecated.theta_est_bootstrap(
+                bootstrap_samples,
+                samplesize=samplesize,
+                replacement=replacement,
+                seed=seed,
+                return_samples=return_samples,
+            )
+
+        assert isinstance(bootstrap_samples, int)
+        assert isinstance(samplesize, (type(None), int))
+        assert isinstance(replacement, bool)
+        assert isinstance(seed, (type(None), int))
+        assert isinstance(return_samples, bool)
+
+        if samplesize is None:
+            samplesize = len(self.exp_list)
+
+        if seed is not None:
+            np.random.seed(seed)
+
+        global_list = self._get_sample_list(samplesize, bootstrap_samples, replacement)
+
+        task_mgr = utils.ParallelTaskManager(bootstrap_samples)
+        local_list = task_mgr.global_to_local_data(global_list)
+
+        bootstrap_theta = list()
+        for idx, sample in local_list:
+            objval, thetavals = self._Q_opt(bootlist=list(sample))
+            thetavals['samples'] = sample
+            bootstrap_theta.append(thetavals)
+
+        global_bootstrap_theta = task_mgr.allgather_global_data(bootstrap_theta)
+        bootstrap_theta = pd.DataFrame(global_bootstrap_theta)
+
+        if not return_samples:
+            del bootstrap_theta['samples']
+
+        return bootstrap_theta
+
+    def theta_est_leaveNout(
+        self, lNo, lNo_samples=None, seed=None, return_samples=False
+    ):
+        """
+        Parameter estimation where N data points are left out of each sample
+
+        Parameters
+        ----------
+        lNo: int
+            Number of data points to leave out for parameter estimation
+        lNo_samples: int
+            Number of leave-N-out samples. If lNo_samples=None, the maximum
+            number of combinations will be used
+        seed: int or None, optional
+            Random seed
+        return_samples: bool, optional
+            Return a list of sample numbers that were left out. Default is False.
+
+        Returns
+        -------
+        lNo_theta: pd.DataFrame
+            Theta values for each sample and (if return_samples = True)
+            the sample numbers left out of each estimation
+        """
+
+        # check if we are using deprecated parmest
+        if self.pest_deprecated is not None:
+            return self.pest_deprecated.theta_est_leaveNout(
+                lNo, lNo_samples=lNo_samples, seed=seed, return_samples=return_samples
+            )
+
+        assert isinstance(lNo, int)
+        assert isinstance(lNo_samples, (type(None), int))
+        assert isinstance(seed, (type(None), int))
+        assert isinstance(return_samples, bool)
+
+        samplesize = len(self.exp_list) - lNo
+
+        if seed is not None:
+            np.random.seed(seed)
+
+        global_list = self._get_sample_list(samplesize, lNo_samples, replacement=False)
+
+        task_mgr = utils.ParallelTaskManager(len(global_list))
+        local_list = task_mgr.global_to_local_data(global_list)
+
+        lNo_theta = list()
+        for idx, sample in local_list:
+            objval, thetavals = self._Q_opt(bootlist=list(sample))
+            lNo_s = list(set(range(len(self.exp_list))) - set(sample))
+            thetavals['lNo'] = np.sort(lNo_s)
+            lNo_theta.append(thetavals)
+
+        global_bootstrap_theta = task_mgr.allgather_global_data(lNo_theta)
+        lNo_theta = pd.DataFrame(global_bootstrap_theta)
+
+        if not return_samples:
+            del lNo_theta['lNo']
+
+        return lNo_theta
+
+    def leaveNout_bootstrap_test(
+        self, lNo, lNo_samples, bootstrap_samples, distribution, alphas, seed=None
+    ):
+        """
+        Leave-N-out bootstrap test to compare theta values where N data points are
+        left out to a bootstrap analysis using the remaining data,
+        results indicate if theta is within a confidence region
+        determined by the bootstrap analysis
+
+        Parameters
+        ----------
+        lNo: int
+            Number of data points to leave out for parameter estimation
+        lNo_samples: int
+            Leave-N-out sample size. If lNo_samples=None, the maximum number
+            of combinations will be used
+        bootstrap_samples: int:
+            Bootstrap sample size
+        distribution: string
+            Statistical distribution used to define a confidence region,
+            options = 'MVN' for multivariate_normal, 'KDE' for gaussian_kde,
+            and 'Rect' for rectangular.
+        alphas: list
+            List of alpha values used to determine if theta values are inside
+            or outside the region.
+        seed: int or None, optional
+            Random seed
+
+        Returns
+        -------
+        List of tuples with one entry per lNo_sample:
+
+        * The first item in each tuple is the list of N samples that are left
+          out.
+        * The second item in each tuple is a DataFrame of theta estimated using
+          the N samples.
+        * The third item in each tuple is a DataFrame containing results from
+          the bootstrap analysis using the remaining samples.
+
+        For each DataFrame a column is added for each value of alpha which
+        indicates if the theta estimate is in (True) or out (False) of the
+        alpha region for a given distribution (based on the bootstrap results)
+        """
+
+        # check if we are using deprecated parmest
+        if self.pest_deprecated is not None:
+            return self.pest_deprecated.leaveNout_bootstrap_test(
+                lNo, lNo_samples, bootstrap_samples, distribution, alphas, seed=seed
+            )
+
+        assert isinstance(lNo, int)
+        assert isinstance(lNo_samples, (type(None), int))
+        assert isinstance(bootstrap_samples, int)
+        assert distribution in ['Rect', 'MVN', 'KDE']
+        assert isinstance(alphas, list)
+        assert isinstance(seed, (type(None), int))
+
+        if seed is not None:
+            np.random.seed(seed)
+
+        global_list = self._get_sample_list(lNo, lNo_samples, replacement=False)
+
+        results = []
+        for idx, sample in global_list:
+
+            obj, theta = self.theta_est()
+
+            bootstrap_theta = self.theta_est_bootstrap(bootstrap_samples)
+
+            training, test = self.confidence_region_test(
+                bootstrap_theta,
+                distribution=distribution,
+                alphas=alphas,
+                test_theta_values=theta,
+            )
+
+            results.append((sample, test, training))
+
+        return results
+
+    def objective_at_theta(self, theta_values=None, initialize_parmest_model=False):
+        """
+        Objective value for each theta
+
+        Parameters
+        ----------
+        theta_values: pd.DataFrame, columns=theta_names
+            Values of theta used to compute the objective
+
+        initialize_parmest_model: boolean
+            If True: Solve square problem instance, build extensive form
+            of the model for parameter estimation, and set flag
+            model_initialized to True. Default is False.
+
+
+        Returns
+        -------
+        obj_at_theta: pd.DataFrame
+            Objective value for each theta (infeasible solutions are
+            omitted).
+        """
+
+        # check if we are using deprecated parmest
+        if self.pest_deprecated is not None:
+            return self.pest_deprecated.objective_at_theta(
+                theta_values=theta_values,
+                initialize_parmest_model=initialize_parmest_model,
+            )
+
+        if len(self.estimator_theta_names) == 0:
+            pass  # skip assertion if model has no fitted parameters
+        else:
+            # create a local instance of the pyomo model to access model variables and parameters
+            model_temp = self._create_parmest_model(0)
+            model_theta_list = self._expand_indexed_unknowns(model_temp)
+
+            # if self.estimator_theta_names is not the same as temp model_theta_list,
+            # create self.theta_names_updated
+            if set(self.estimator_theta_names) == set(model_theta_list) and len(
+                self.estimator_theta_names
+            ) == len(set(model_theta_list)):
+                pass
+            else:
+                self.theta_names_updated = model_theta_list
+
+        if theta_values is None:
+            all_thetas = {}  # dictionary to store fitted variables
+            # use appropriate theta names member
+            theta_names = model_theta_list
+        else:
+            assert isinstance(theta_values, pd.DataFrame)
+            # for parallel code we need to use lists and dicts in the loop
+            theta_names = theta_values.columns
+            # # check if theta_names are in model
+            for theta in list(theta_names):
+                theta_temp = theta.replace("'", "")  # cleaning quotes from theta_names
+                assert theta_temp in [
+                    t.replace("'", "") for t in model_theta_list
+                ], "Theta name {} in 'theta_values' not in 'theta_names' {}".format(
+                    theta_temp, model_theta_list
+                )
+
+            assert len(list(theta_names)) == len(model_theta_list)
+
+            all_thetas = theta_values.to_dict('records')
+
+        if all_thetas:
+            task_mgr = utils.ParallelTaskManager(len(all_thetas))
+            local_thetas = task_mgr.global_to_local_data(all_thetas)
+        else:
+            if initialize_parmest_model:
+                task_mgr = utils.ParallelTaskManager(
+                    1
+                )  # initialization performed using just 1 set of theta values
+        # walk over the mesh, return objective function
+        all_obj = list()
+        if len(all_thetas) > 0:
+            for Theta in local_thetas:
+                obj, thetvals, worststatus = self._Q_at_theta(
+                    Theta, initialize_parmest_model=initialize_parmest_model
+                )
+                if worststatus != pyo.TerminationCondition.infeasible:
+                    all_obj.append(list(Theta.values()) + [obj])
+                # DLW, Aug2018: should we also store the worst solver status?
+        else:
+            obj, thetvals, worststatus = self._Q_at_theta(
+                thetavals={}, initialize_parmest_model=initialize_parmest_model
+            )
+            if worststatus != pyo.TerminationCondition.infeasible:
+                all_obj.append(list(thetvals.values()) + [obj])
+
+        global_all_obj = task_mgr.allgather_global_data(all_obj)
+        dfcols = list(theta_names) + ['obj']
+        obj_at_theta = pd.DataFrame(data=global_all_obj, columns=dfcols)
+        return obj_at_theta
+
+    def likelihood_ratio_test(
+        self, obj_at_theta, obj_value, alphas, return_thresholds=False
+    ):
+        r"""
+        Likelihood ratio test to identify theta values within a confidence
+        region using the :math:`\chi^2` distribution
+
+        Parameters
+        ----------
+        obj_at_theta: pd.DataFrame, columns = theta_names + 'obj'
+            Objective values for each theta value (returned by
+            objective_at_theta)
+        obj_value: int or float
+            Objective value from parameter estimation using all data
+        alphas: list
+            List of alpha values to use in the chi2 test
+        return_thresholds: bool, optional
+            Return the threshold value for each alpha. Default is False.
+
+        Returns
+        -------
+        LR: pd.DataFrame
+            Objective values for each theta value along with True or False for
+            each alpha
+        thresholds: pd.Series
+            If return_threshold = True, the thresholds are also returned.
+        """
+
+        # check if we are using deprecated parmest
+        if self.pest_deprecated is not None:
+            return self.pest_deprecated.likelihood_ratio_test(
+                obj_at_theta, obj_value, alphas, return_thresholds=return_thresholds
+            )
+
+        assert isinstance(obj_at_theta, pd.DataFrame)
+        assert isinstance(obj_value, (int, float))
+        assert isinstance(alphas, list)
+        assert isinstance(return_thresholds, bool)
+
+        LR = obj_at_theta.copy()
+        S = len(self.exp_list)
+        thresholds = {}
+        for a in alphas:
+            chi2_val = scipy.stats.chi2.ppf(a, 2)
+            thresholds[a] = obj_value * ((chi2_val / (S - 2)) + 1)
+            LR[a] = LR['obj'] < thresholds[a]
+
+        thresholds = pd.Series(thresholds)
+
+        if return_thresholds:
+            return LR, thresholds
+        else:
+            return LR
+
+    def confidence_region_test(
+        self, theta_values, distribution, alphas, test_theta_values=None
+    ):
+        """
+        Confidence region test to determine if theta values are within a
+        rectangular, multivariate normal, or Gaussian kernel density distribution
+        for a range of alpha values
+
+        Parameters
+        ----------
+        theta_values: pd.DataFrame, columns = theta_names
+            Theta values used to generate a confidence region
+            (generally returned by theta_est_bootstrap)
+        distribution: string
+            Statistical distribution used to define a confidence region,
+            options = 'MVN' for multivariate_normal, 'KDE' for gaussian_kde,
+            and 'Rect' for rectangular.
+        alphas: list
+            List of alpha values used to determine if theta values are inside
+            or outside the region.
+        test_theta_values: pd.Series or pd.DataFrame, keys/columns = theta_names, optional
+            Additional theta values that are compared to the confidence region
+            to determine if they are inside or outside.
+
+        Returns
+        -------
+        training_results: pd.DataFrame
+            Theta value used to generate the confidence region along with True
+            (inside) or False (outside) for each alpha
+        test_results: pd.DataFrame
+            If test_theta_values is not None, returns test theta value along
+            with True (inside) or False (outside) for each alpha
+        """
+
+        # check if we are using deprecated parmest
+        if self.pest_deprecated is not None:
+            return self.pest_deprecated.confidence_region_test(
+                theta_values, distribution, alphas, test_theta_values=test_theta_values
+            )
+
+        assert isinstance(theta_values, pd.DataFrame)
+        assert distribution in ['Rect', 'MVN', 'KDE']
+        assert isinstance(alphas, list)
+        assert isinstance(
+            test_theta_values, (type(None), dict, pd.Series, pd.DataFrame)
+        )
+
+        if isinstance(test_theta_values, (dict, pd.Series)):
+            test_theta_values = pd.Series(test_theta_values).to_frame().transpose()
+
+        training_results = theta_values.copy()
+
+        if test_theta_values is not None:
+            test_result = test_theta_values.copy()
+
+        for a in alphas:
+            if distribution == 'Rect':
+                lb, ub = graphics.fit_rect_dist(theta_values, a)
+                training_results[a] = (theta_values > lb).all(axis=1) & (
+                    theta_values < ub
+                ).all(axis=1)
+
+                if test_theta_values is not None:
+                    # use upper and lower bound from the training set
+                    test_result[a] = (test_theta_values > lb).all(axis=1) & (
+                        test_theta_values < ub
+                    ).all(axis=1)
+
+            elif distribution == 'MVN':
+                dist = graphics.fit_mvn_dist(theta_values)
+                Z = dist.pdf(theta_values)
+                score = scipy.stats.scoreatpercentile(Z, (1 - a) * 100)
+                training_results[a] = Z >= score
+
+                if test_theta_values is not None:
+                    # use score from the training set
+                    Z = dist.pdf(test_theta_values)
+                    test_result[a] = Z >= score
+
+            elif distribution == 'KDE':
+                dist = graphics.fit_kde_dist(theta_values)
+                Z = dist.pdf(theta_values.transpose())
+                score = scipy.stats.scoreatpercentile(Z, (1 - a) * 100)
+                training_results[a] = Z >= score
+
+                if test_theta_values is not None:
+                    # use score from the training set
+                    Z = dist.pdf(test_theta_values.transpose())
+                    test_result[a] = Z >= score
+
+        if test_theta_values is not None:
+            return training_results, test_result
+        else:
+            return training_results
+
+
+################################
+# deprecated functions/classes #
+################################
+
+
+@deprecated(version='6.7.2')
+def group_data(data, groupby_column_name, use_mean=None):
+    """
+    Group data by scenario
+
+    Parameters
+    ----------
+    data: DataFrame
+        Data
+    groupby_column_name: strings
+        Name of data column which contains scenario numbers
+    use_mean: list of column names or None, optional
+        Name of data columns which should be reduced to a single value per
+        scenario by taking the mean
+
+    Returns
+    ----------
+    grouped_data: list of dictionaries
+        Grouped data
+    """
+    if use_mean is None:
+        use_mean_list = []
+    else:
+        use_mean_list = use_mean
+
+    grouped_data = []
+    for exp_num, group in data.groupby(data[groupby_column_name]):
+        d = {}
+        for col in group.columns:
+            if col in use_mean_list:
+                d[col] = group[col].mean()
+            else:
+                d[col] = list(group[col])
+        grouped_data.append(d)
+
+    return grouped_data
+
+
+class _DeprecatedSecondStageCostExpr(object):
+    """
+    Class to pass objective expression into the Pyomo model
+    """
+
+    def __init__(self, ssc_function, data):
+        self._ssc_function = ssc_function
+        self._data = data
+
+    def __call__(self, model):
+        return self._ssc_function(model, self._data)
+
+
+class _DeprecatedEstimator(object):
     """
     Parameter estimation class
 
@@ -418,7 +1545,7 @@ def _create_parmest_model(self, data):
                     )
             model.FirstStageCost = pyo.Expression(expr=0)
             model.SecondStageCost = pyo.Expression(
-                rule=_SecondStageCostExpr(self.obj_function, data)
+                rule=_DeprecatedSecondStageCostExpr(self.obj_function, data)
             )
 
             def TotalCost_rule(model):
diff --git a/pyomo/contrib/parmest/scenariocreator.py b/pyomo/contrib/parmest/scenariocreator.py
index 58d2d4da722..e887dd2e8be 100644
--- a/pyomo/contrib/parmest/scenariocreator.py
+++ b/pyomo/contrib/parmest/scenariocreator.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -14,6 +14,10 @@
 
 import pyomo.environ as pyo
 
+import logging
+
+logger = logging.getLogger(__name__)
+
 
 class ScenarioSet(object):
     """
@@ -119,6 +123,7 @@ class ScenarioCreator(object):
     """
 
     def __init__(self, pest, solvername):
+
         self.pest = pest
         self.solvername = solvername
 
@@ -133,23 +138,32 @@ def ScenariosFromExperiments(self, addtoSet):
 
         assert isinstance(addtoSet, ScenarioSet)
 
-        scenario_numbers = list(range(len(self.pest.callback_data)))
+        if self.pest.pest_deprecated is not None:
+            scenario_numbers = list(range(len(self.pest.pest_deprecated.callback_data)))
+        else:
+            scenario_numbers = list(range(len(self.pest.exp_list)))
 
         prob = 1.0 / len(scenario_numbers)
         for exp_num in scenario_numbers:
             ##print("Experiment number=", exp_num)
-            model = self.pest._instance_creation_callback(
-                exp_num, self.pest.callback_data
-            )
+            if self.pest.pest_deprecated is not None:
+                model = self.pest.pest_deprecated._instance_creation_callback(
+                    exp_num, self.pest.pest_deprecated.callback_data
+                )
+            else:
+                model = self.pest._instance_creation_callback(exp_num)
             opt = pyo.SolverFactory(self.solvername)
             results = opt.solve(model)  # solves and updates model
             ## pyo.check_termination_optimal(results)
-            ThetaVals = dict()
-            for theta in self.pest.theta_names:
-                tvar = eval('model.' + theta)
-                tval = pyo.value(tvar)
-                ##print("    theta, tval=", tvar, tval)
-                ThetaVals[theta] = tval
+            if self.pest.pest_deprecated is not None:
+                ThetaVals = {
+                    theta: pyo.value(model.find_component(theta))
+                    for theta in self.pest.pest_deprecated.theta_names
+                }
+            else:
+                ThetaVals = {
+                    k.name: pyo.value(k) for k in model.unknown_parameters.keys()
+                }
             addtoSet.addone(ParmestScen("ExpScen" + str(exp_num), ThetaVals, prob))
 
     def ScenariosFromBootstrap(self, addtoSet, numtomake, seed=None):
@@ -162,5 +176,10 @@ def ScenariosFromBootstrap(self, addtoSet, numtomake, seed=None):
 
         assert isinstance(addtoSet, ScenarioSet)
 
-        bootstrap_thetas = self.pest.theta_est_bootstrap(numtomake, seed=seed)
+        if self.pest.pest_deprecated is not None:
+            bootstrap_thetas = self.pest.pest_deprecated.theta_est_bootstrap(
+                numtomake, seed=seed
+            )
+        else:
+            bootstrap_thetas = self.pest.theta_est_bootstrap(numtomake, seed=seed)
         addtoSet.append_bootstrap(bootstrap_thetas)
diff --git a/pyomo/contrib/parmest/tests/__init__.py b/pyomo/contrib/parmest/tests/__init__.py
index d93cfd77b3c..a4a626013c4 100644
--- a/pyomo/contrib/parmest/tests/__init__.py
+++ b/pyomo/contrib/parmest/tests/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/parmest/tests/test_examples.py b/pyomo/contrib/parmest/tests/test_examples.py
index 67e06130384..dca05026e80 100644
--- a/pyomo/contrib/parmest/tests/test_examples.py
+++ b/pyomo/contrib/parmest/tests/test_examples.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -181,7 +181,10 @@ def test_multisensor_data_example(self):
 
         multisensor_data_example.main()
 
-    @unittest.skipUnless(matplotlib_available, "test requires matplotlib")
+    @unittest.skipUnless(
+        matplotlib_available and seaborn_available,
+        "test requires matplotlib and seaborn",
+    )
     def test_datarec_example(self):
         from pyomo.contrib.parmest.examples.reactor_design import datarec_example
 
diff --git a/pyomo/contrib/parmest/tests/test_graphics.py b/pyomo/contrib/parmest/tests/test_graphics.py
index c18659e9948..3b4d0224ebe 100644
--- a/pyomo/contrib/parmest/tests/test_graphics.py
+++ b/pyomo/contrib/parmest/tests/test_graphics.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/parmest/tests/test_parmest.py b/pyomo/contrib/parmest/tests/test_parmest.py
index b5c1fe1bfac..65e2e4a3b06 100644
--- a/pyomo/contrib/parmest/tests/test_parmest.py
+++ b/pyomo/contrib/parmest/tests/test_parmest.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -33,6 +33,7 @@
 import pyomo.contrib.parmest.parmest as parmest
 import pyomo.contrib.parmest.graphics as graphics
 import pyomo.contrib.parmest as parmestbase
+from pyomo.contrib.parmest.experiment import Experiment
 import pyomo.environ as pyo
 import pyomo.dae as dae
 
@@ -55,8 +56,1019 @@
 class TestRooneyBiegler(unittest.TestCase):
     def setUp(self):
         from pyomo.contrib.parmest.examples.rooney_biegler.rooney_biegler import (
-            rooney_biegler_model,
+            RooneyBieglerExperiment,
+        )
+
+        # Note, the data used in this test has been corrected to use
+        # data.loc[5,'hour'] = 7 (instead of 6)
+        data = pd.DataFrame(
+            data=[[1, 8.3], [2, 10.3], [3, 19.0], [4, 16.0], [5, 15.6], [7, 19.8]],
+            columns=["hour", "y"],
+        )
+
+        # Sum of squared error function
+        def SSE(model):
+            expr = (
+                model.experiment_outputs[model.y]
+                - model.response_function[model.experiment_outputs[model.hour]]
+            ) ** 2
+            return expr
+
+        # Create an experiment list
+        exp_list = []
+        for i in range(data.shape[0]):
+            exp_list.append(RooneyBieglerExperiment(data.loc[i, :]))
+
+        # Create an instance of the parmest estimator
+        pest = parmest.Estimator(exp_list, obj_function=SSE)
+
+        solver_options = {"tol": 1e-8}
+
+        self.data = data
+        self.pest = parmest.Estimator(
+            exp_list, obj_function=SSE, solver_options=solver_options, tee=True
+        )
+
+    def test_theta_est(self):
+        objval, thetavals = self.pest.theta_est()
+
+        self.assertAlmostEqual(objval, 4.3317112, places=2)
+        self.assertAlmostEqual(
+            thetavals["asymptote"], 19.1426, places=2
+        )  # 19.1426 from the paper
+        self.assertAlmostEqual(
+            thetavals["rate_constant"], 0.5311, places=2
+        )  # 0.5311 from the paper
+
+    @unittest.skipIf(
+        not graphics.imports_available, "parmest.graphics imports are unavailable"
+    )
+    def test_bootstrap(self):
+        objval, thetavals = self.pest.theta_est()
+
+        num_bootstraps = 10
+        theta_est = self.pest.theta_est_bootstrap(num_bootstraps, return_samples=True)
+
+        num_samples = theta_est["samples"].apply(len)
+        self.assertEqual(len(theta_est.index), 10)
+        self.assertTrue(num_samples.equals(pd.Series([6] * 10)))
+
+        del theta_est["samples"]
+
+        # apply confidence region test
+        CR = self.pest.confidence_region_test(theta_est, "MVN", [0.5, 0.75, 1.0])
+
+        self.assertTrue(set(CR.columns) >= set([0.5, 0.75, 1.0]))
+        self.assertEqual(CR[0.5].sum(), 5)
+        self.assertEqual(CR[0.75].sum(), 7)
+        self.assertEqual(CR[1.0].sum(), 10)  # all true
+
+        graphics.pairwise_plot(theta_est)
+        graphics.pairwise_plot(theta_est, thetavals)
+        graphics.pairwise_plot(theta_est, thetavals, 0.8, ["MVN", "KDE", "Rect"])
+
+    @unittest.skipIf(
+        not graphics.imports_available, "parmest.graphics imports are unavailable"
+    )
+    def test_likelihood_ratio(self):
+        objval, thetavals = self.pest.theta_est()
+
+        asym = np.arange(10, 30, 2)
+        rate = np.arange(0, 1.5, 0.25)
+        theta_vals = pd.DataFrame(
+            list(product(asym, rate)), columns=['asymptote', 'rate_constant']
+        )
+        obj_at_theta = self.pest.objective_at_theta(theta_vals)
+
+        LR = self.pest.likelihood_ratio_test(obj_at_theta, objval, [0.8, 0.9, 1.0])
+
+        self.assertTrue(set(LR.columns) >= set([0.8, 0.9, 1.0]))
+        self.assertEqual(LR[0.8].sum(), 6)
+        self.assertEqual(LR[0.9].sum(), 10)
+        self.assertEqual(LR[1.0].sum(), 60)  # all true
+
+        graphics.pairwise_plot(LR, thetavals, 0.8)
+
+    def test_leaveNout(self):
+        lNo_theta = self.pest.theta_est_leaveNout(1)
+        self.assertTrue(lNo_theta.shape == (6, 2))
+
+        results = self.pest.leaveNout_bootstrap_test(
+            1, None, 3, "Rect", [0.5, 1.0], seed=5436
+        )
+        self.assertEqual(len(results), 6)  # 6 lNo samples
+        i = 1
+        samples = results[i][0]  # list of N samples that are left out
+        lno_theta = results[i][1]
+        bootstrap_theta = results[i][2]
+        self.assertTrue(samples == [1])  # sample 1 was left out
+        self.assertEqual(lno_theta.shape[0], 1)  # lno estimate for sample 1
+        self.assertTrue(set(lno_theta.columns) >= set([0.5, 1.0]))
+        self.assertEqual(lno_theta[1.0].sum(), 1)  # all true
+        self.assertEqual(bootstrap_theta.shape[0], 3)  # bootstrap for sample 1
+        self.assertEqual(bootstrap_theta[1.0].sum(), 3)  # all true
+
+    def test_diagnostic_mode(self):
+        self.pest.diagnostic_mode = True
+
+        objval, thetavals = self.pest.theta_est()
+
+        asym = np.arange(10, 30, 2)
+        rate = np.arange(0, 1.5, 0.25)
+        theta_vals = pd.DataFrame(
+            list(product(asym, rate)), columns=['asymptote', 'rate_constant']
+        )
+
+        obj_at_theta = self.pest.objective_at_theta(theta_vals)
+
+        self.pest.diagnostic_mode = False
+
+    @unittest.skip("Presently having trouble with mpiexec on appveyor")
+    def test_parallel_parmest(self):
+        """use mpiexec and mpi4py"""
+        p = str(parmestbase.__path__)
+        l = p.find("'")
+        r = p.find("'", l + 1)
+        parmestpath = p[l + 1 : r]
+        rbpath = (
+            parmestpath
+            + os.sep
+            + "examples"
+            + os.sep
+            + "rooney_biegler"
+            + os.sep
+            + "rooney_biegler_parmest.py"
+        )
+        rbpath = os.path.abspath(rbpath)  # paranoia strikes deep...
+        rlist = ["mpiexec", "--allow-run-as-root", "-n", "2", sys.executable, rbpath]
+        if sys.version_info >= (3, 5):
+            ret = subprocess.run(rlist)
+            retcode = ret.returncode
+        else:
+            retcode = subprocess.call(rlist)
+        self.assertEqual(retcode, 0)
+
+    @unittest.skip("Most folks don't have k_aug installed")
+    def test_theta_k_aug_for_Hessian(self):
+        # this will fail if k_aug is not installed
+        objval, thetavals, Hessian = self.pest.theta_est(solver="k_aug")
+        self.assertAlmostEqual(objval, 4.4675, places=2)
+
+    @unittest.skipIf(not pynumero_ASL_available, "pynumero ASL is not available")
+    @unittest.skipIf(
+        not parmest.inverse_reduced_hessian_available,
+        "Cannot test covariance matrix: required ASL dependency is missing",
+    )
+    def test_theta_est_cov(self):
+        objval, thetavals, cov = self.pest.theta_est(calc_cov=True, cov_n=6)
+
+        self.assertAlmostEqual(objval, 4.3317112, places=2)
+        self.assertAlmostEqual(
+            thetavals["asymptote"], 19.1426, places=2
+        )  # 19.1426 from the paper
+        self.assertAlmostEqual(
+            thetavals["rate_constant"], 0.5311, places=2
+        )  # 0.5311 from the paper
+
+        # Covariance matrix
+        self.assertAlmostEqual(
+            cov["asymptote"]["asymptote"], 6.30579403, places=2
+        )  # 6.22864 from paper
+        self.assertAlmostEqual(
+            cov["asymptote"]["rate_constant"], -0.4395341, places=2
+        )  # -0.4322 from paper
+        self.assertAlmostEqual(
+            cov["rate_constant"]["asymptote"], -0.4395341, places=2
+        )  # -0.4322 from paper
+        self.assertAlmostEqual(
+            cov["rate_constant"]["rate_constant"], 0.04124, places=2
+        )  # 0.04124 from paper
+
+        """ Why does the covariance matrix from parmest not match the paper? Parmest is
+        calculating the exact reduced Hessian. The paper (Rooney and Bielger, 2001) likely
+        employed the first order approximation common for nonlinear regression. The paper
+        values were verified with Scipy, which uses the same first order approximation.
+        The formula used in parmest was verified against equations (7-5-15) and (7-5-16) in
+        "Nonlinear Parameter Estimation", Y. Bard, 1974.
+        """
+
+    def test_cov_scipy_least_squares_comparison(self):
+        """
+        Scipy results differ in the 3rd decimal place from the paper. It is possible
+        the paper used an alternative finite difference approximation for the Jacobian.
+        """
+
+        def model(theta, t):
+            """
+            Model to be fitted y = model(theta, t)
+            Arguments:
+                theta: vector of fitted parameters
+                t: independent variable [hours]
+
+            Returns:
+                y: model predictions [need to check paper for units]
+            """
+            asymptote = theta[0]
+            rate_constant = theta[1]
+
+            return asymptote * (1 - np.exp(-rate_constant * t))
+
+        def residual(theta, t, y):
+            """
+            Calculate residuals
+            Arguments:
+                theta: vector of fitted parameters
+                t: independent variable [hours]
+                y: dependent variable [?]
+            """
+            return y - model(theta, t)
+
+        # define data
+        t = self.data["hour"].to_numpy()
+        y = self.data["y"].to_numpy()
+
+        # define initial guess
+        theta_guess = np.array([15, 0.5])
+
+        ## solve with optimize.least_squares
+        sol = scipy.optimize.least_squares(
+            residual, theta_guess, method="trf", args=(t, y), verbose=2
+        )
+        theta_hat = sol.x
+
+        self.assertAlmostEqual(
+            theta_hat[0], 19.1426, places=2
+        )  # 19.1426 from the paper
+        self.assertAlmostEqual(theta_hat[1], 0.5311, places=2)  # 0.5311 from the paper
+
+        # calculate residuals
+        r = residual(theta_hat, t, y)
+
+        # calculate variance of the residuals
+        # -2 because there are 2 fitted parameters
+        sigre = np.matmul(r.T, r / (len(y) - 2))
+
+        # approximate covariance
+        # Need to divide by 2 because optimize.least_squares scaled the objective by 1/2
+        cov = sigre * np.linalg.inv(np.matmul(sol.jac.T, sol.jac))
+
+        self.assertAlmostEqual(cov[0, 0], 6.22864, places=2)  # 6.22864 from paper
+        self.assertAlmostEqual(cov[0, 1], -0.4322, places=2)  # -0.4322 from paper
+        self.assertAlmostEqual(cov[1, 0], -0.4322, places=2)  # -0.4322 from paper
+        self.assertAlmostEqual(cov[1, 1], 0.04124, places=2)  # 0.04124 from paper
+
+    def test_cov_scipy_curve_fit_comparison(self):
+        """
+        Scipy results differ in the 3rd decimal place from the paper. It is possible
+        the paper used an alternative finite difference approximation for the Jacobian.
+        """
+
+        ## solve with optimize.curve_fit
+        def model(t, asymptote, rate_constant):
+            return asymptote * (1 - np.exp(-rate_constant * t))
+
+        # define data
+        t = self.data["hour"].to_numpy()
+        y = self.data["y"].to_numpy()
+
+        # define initial guess
+        theta_guess = np.array([15, 0.5])
+
+        theta_hat, cov = scipy.optimize.curve_fit(model, t, y, p0=theta_guess)
+
+        self.assertAlmostEqual(
+            theta_hat[0], 19.1426, places=2
+        )  # 19.1426 from the paper
+        self.assertAlmostEqual(theta_hat[1], 0.5311, places=2)  # 0.5311 from the paper
+
+        self.assertAlmostEqual(cov[0, 0], 6.22864, places=2)  # 6.22864 from paper
+        self.assertAlmostEqual(cov[0, 1], -0.4322, places=2)  # -0.4322 from paper
+        self.assertAlmostEqual(cov[1, 0], -0.4322, places=2)  # -0.4322 from paper
+        self.assertAlmostEqual(cov[1, 1], 0.04124, places=2)  # 0.04124 from paper
+
+
+@unittest.skipIf(
+    not parmest.parmest_available,
+    "Cannot test parmest: required dependencies are missing",
+)
+@unittest.skipIf(not ipopt_available, "The 'ipopt' command is not available")
+class TestModelVariants(unittest.TestCase):
+
+    def setUp(self):
+        from pyomo.contrib.parmest.examples.rooney_biegler.rooney_biegler import (
+            RooneyBieglerExperiment,
+        )
+
+        self.data = pd.DataFrame(
+            data=[[1, 8.3], [2, 10.3], [3, 19.0], [4, 16.0], [5, 15.6], [7, 19.8]],
+            columns=["hour", "y"],
+        )
+
+        def rooney_biegler_params(data):
+            model = pyo.ConcreteModel()
+
+            model.asymptote = pyo.Param(initialize=15, mutable=True)
+            model.rate_constant = pyo.Param(initialize=0.5, mutable=True)
+
+            model.hour = pyo.Param(within=pyo.PositiveReals, mutable=True)
+            model.y = pyo.Param(within=pyo.PositiveReals, mutable=True)
+
+            def response_rule(m, h):
+                expr = m.asymptote * (1 - pyo.exp(-m.rate_constant * h))
+                return expr
+
+            model.response_function = pyo.Expression(data.hour, rule=response_rule)
+
+            return model
+
+        class RooneyBieglerExperimentParams(RooneyBieglerExperiment):
+
+            def create_model(self):
+                data_df = self.data.to_frame().transpose()
+                self.model = rooney_biegler_params(data_df)
+
+        rooney_biegler_params_exp_list = []
+        for i in range(self.data.shape[0]):
+            rooney_biegler_params_exp_list.append(
+                RooneyBieglerExperimentParams(self.data.loc[i, :])
+            )
+
+        def rooney_biegler_indexed_params(data):
+            model = pyo.ConcreteModel()
+
+            model.param_names = pyo.Set(initialize=["asymptote", "rate_constant"])
+            model.theta = pyo.Param(
+                model.param_names,
+                initialize={"asymptote": 15, "rate_constant": 0.5},
+                mutable=True,
+            )
+
+            model.hour = pyo.Param(within=pyo.PositiveReals, mutable=True)
+            model.y = pyo.Param(within=pyo.PositiveReals, mutable=True)
+
+            def response_rule(m, h):
+                expr = m.theta["asymptote"] * (
+                    1 - pyo.exp(-m.theta["rate_constant"] * h)
+                )
+                return expr
+
+            model.response_function = pyo.Expression(data.hour, rule=response_rule)
+
+            return model
+
+        class RooneyBieglerExperimentIndexedParams(RooneyBieglerExperiment):
+
+            def create_model(self):
+                data_df = self.data.to_frame().transpose()
+                self.model = rooney_biegler_indexed_params(data_df)
+
+            def label_model(self):
+
+                m = self.model
+
+                m.experiment_outputs = pyo.Suffix(direction=pyo.Suffix.LOCAL)
+                m.experiment_outputs.update(
+                    [(m.hour, self.data["hour"]), (m.y, self.data["y"])]
+                )
+
+                m.unknown_parameters = pyo.Suffix(direction=pyo.Suffix.LOCAL)
+                m.unknown_parameters.update((k, pyo.ComponentUID(k)) for k in [m.theta])
+
+        rooney_biegler_indexed_params_exp_list = []
+        for i in range(self.data.shape[0]):
+            rooney_biegler_indexed_params_exp_list.append(
+                RooneyBieglerExperimentIndexedParams(self.data.loc[i, :])
+            )
+
+        def rooney_biegler_vars(data):
+            model = pyo.ConcreteModel()
+
+            model.asymptote = pyo.Var(initialize=15)
+            model.rate_constant = pyo.Var(initialize=0.5)
+            model.asymptote.fixed = True  # parmest will unfix theta variables
+            model.rate_constant.fixed = True
+
+            model.hour = pyo.Param(within=pyo.PositiveReals, mutable=True)
+            model.y = pyo.Param(within=pyo.PositiveReals, mutable=True)
+
+            def response_rule(m, h):
+                expr = m.asymptote * (1 - pyo.exp(-m.rate_constant * h))
+                return expr
+
+            model.response_function = pyo.Expression(data.hour, rule=response_rule)
+
+            return model
+
+        class RooneyBieglerExperimentVars(RooneyBieglerExperiment):
+
+            def create_model(self):
+                data_df = self.data.to_frame().transpose()
+                self.model = rooney_biegler_vars(data_df)
+
+        rooney_biegler_vars_exp_list = []
+        for i in range(self.data.shape[0]):
+            rooney_biegler_vars_exp_list.append(
+                RooneyBieglerExperimentVars(self.data.loc[i, :])
+            )
+
+        def rooney_biegler_indexed_vars(data):
+            model = pyo.ConcreteModel()
+
+            model.var_names = pyo.Set(initialize=["asymptote", "rate_constant"])
+            model.theta = pyo.Var(
+                model.var_names, initialize={"asymptote": 15, "rate_constant": 0.5}
+            )
+            model.theta["asymptote"].fixed = (
+                True  # parmest will unfix theta variables, even when they are indexed
+            )
+            model.theta["rate_constant"].fixed = True
+
+            model.hour = pyo.Param(within=pyo.PositiveReals, mutable=True)
+            model.y = pyo.Param(within=pyo.PositiveReals, mutable=True)
+
+            def response_rule(m, h):
+                expr = m.theta["asymptote"] * (
+                    1 - pyo.exp(-m.theta["rate_constant"] * h)
+                )
+                return expr
+
+            model.response_function = pyo.Expression(data.hour, rule=response_rule)
+
+            return model
+
+        class RooneyBieglerExperimentIndexedVars(RooneyBieglerExperiment):
+
+            def create_model(self):
+                data_df = self.data.to_frame().transpose()
+                self.model = rooney_biegler_indexed_vars(data_df)
+
+            def label_model(self):
+
+                m = self.model
+
+                m.experiment_outputs = pyo.Suffix(direction=pyo.Suffix.LOCAL)
+                m.experiment_outputs.update(
+                    [(m.hour, self.data["hour"]), (m.y, self.data["y"])]
+                )
+
+                m.unknown_parameters = pyo.Suffix(direction=pyo.Suffix.LOCAL)
+                m.unknown_parameters.update((k, pyo.ComponentUID(k)) for k in [m.theta])
+
+        rooney_biegler_indexed_vars_exp_list = []
+        for i in range(self.data.shape[0]):
+            rooney_biegler_indexed_vars_exp_list.append(
+                RooneyBieglerExperimentIndexedVars(self.data.loc[i, :])
+            )
+
+        # Sum of squared error function
+        def SSE(model):
+            expr = (
+                model.experiment_outputs[model.y]
+                - model.response_function[model.experiment_outputs[model.hour]]
+            ) ** 2
+            return expr
+
+        self.objective_function = SSE
+
+        theta_vals = pd.DataFrame([20, 1], index=["asymptote", "rate_constant"]).T
+        theta_vals_index = pd.DataFrame(
+            [20, 1], index=["theta['asymptote']", "theta['rate_constant']"]
+        ).T
+
+        self.input = {
+            "param": {
+                "exp_list": rooney_biegler_params_exp_list,
+                "theta_names": ["asymptote", "rate_constant"],
+                "theta_vals": theta_vals,
+            },
+            "param_index": {
+                "exp_list": rooney_biegler_indexed_params_exp_list,
+                "theta_names": ["theta"],
+                "theta_vals": theta_vals_index,
+            },
+            "vars": {
+                "exp_list": rooney_biegler_vars_exp_list,
+                "theta_names": ["asymptote", "rate_constant"],
+                "theta_vals": theta_vals,
+            },
+            "vars_index": {
+                "exp_list": rooney_biegler_indexed_vars_exp_list,
+                "theta_names": ["theta"],
+                "theta_vals": theta_vals_index,
+            },
+            "vars_quoted_index": {
+                "exp_list": rooney_biegler_indexed_vars_exp_list,
+                "theta_names": ["theta['asymptote']", "theta['rate_constant']"],
+                "theta_vals": theta_vals_index,
+            },
+            "vars_str_index": {
+                "exp_list": rooney_biegler_indexed_vars_exp_list,
+                "theta_names": ["theta[asymptote]", "theta[rate_constant]"],
+                "theta_vals": theta_vals_index,
+            },
+        }
+
+    @unittest.skipIf(not pynumero_ASL_available, "pynumero ASL is not available")
+    @unittest.skipIf(
+        not parmest.inverse_reduced_hessian_available,
+        "Cannot test covariance matrix: required ASL dependency is missing",
+    )
+    def check_rooney_biegler_results(self, objval, cov):
+
+        # get indices in covariance matrix
+        cov_cols = cov.columns.to_list()
+        asymptote_index = [idx for idx, s in enumerate(cov_cols) if "asymptote" in s][0]
+        rate_constant_index = [
+            idx for idx, s in enumerate(cov_cols) if "rate_constant" in s
+        ][0]
+
+        self.assertAlmostEqual(objval, 4.3317112, places=2)
+        self.assertAlmostEqual(
+            cov.iloc[asymptote_index, asymptote_index], 6.30579403, places=2
+        )  # 6.22864 from paper
+        self.assertAlmostEqual(
+            cov.iloc[asymptote_index, rate_constant_index], -0.4395341, places=2
+        )  # -0.4322 from paper
+        self.assertAlmostEqual(
+            cov.iloc[rate_constant_index, asymptote_index], -0.4395341, places=2
+        )  # -0.4322 from paper
+        self.assertAlmostEqual(
+            cov.iloc[rate_constant_index, rate_constant_index], 0.04193591, places=2
+        )  # 0.04124 from paper
+
+    def test_parmest_basics(self):
+
+        for model_type, parmest_input in self.input.items():
+            pest = parmest.Estimator(
+                parmest_input["exp_list"], obj_function=self.objective_function
+            )
+
+            objval, thetavals, cov = pest.theta_est(calc_cov=True, cov_n=6)
+            self.check_rooney_biegler_results(objval, cov)
+
+            obj_at_theta = pest.objective_at_theta(parmest_input["theta_vals"])
+            self.assertAlmostEqual(obj_at_theta["obj"][0], 16.531953, places=2)
+
+    def test_parmest_basics_with_initialize_parmest_model_option(self):
+
+        for model_type, parmest_input in self.input.items():
+            pest = parmest.Estimator(
+                parmest_input["exp_list"], obj_function=self.objective_function
+            )
+
+            objval, thetavals, cov = pest.theta_est(calc_cov=True, cov_n=6)
+            self.check_rooney_biegler_results(objval, cov)
+
+            obj_at_theta = pest.objective_at_theta(
+                parmest_input["theta_vals"], initialize_parmest_model=True
+            )
+
+            self.assertAlmostEqual(obj_at_theta["obj"][0], 16.531953, places=2)
+
+    def test_parmest_basics_with_square_problem_solve(self):
+
+        for model_type, parmest_input in self.input.items():
+            pest = parmest.Estimator(
+                parmest_input["exp_list"], obj_function=self.objective_function
+            )
+
+            obj_at_theta = pest.objective_at_theta(
+                parmest_input["theta_vals"], initialize_parmest_model=True
+            )
+
+            objval, thetavals, cov = pest.theta_est(calc_cov=True, cov_n=6)
+            self.check_rooney_biegler_results(objval, cov)
+
+            self.assertAlmostEqual(obj_at_theta["obj"][0], 16.531953, places=2)
+
+    def test_parmest_basics_with_square_problem_solve_no_theta_vals(self):
+
+        for model_type, parmest_input in self.input.items():
+
+            pest = parmest.Estimator(
+                parmest_input["exp_list"], obj_function=self.objective_function
+            )
+
+            obj_at_theta = pest.objective_at_theta(initialize_parmest_model=True)
+
+            objval, thetavals, cov = pest.theta_est(calc_cov=True, cov_n=6)
+            self.check_rooney_biegler_results(objval, cov)
+
+
+@unittest.skipIf(
+    not parmest.parmest_available,
+    "Cannot test parmest: required dependencies are missing",
+)
+@unittest.skipIf(not ipopt_available, "The 'ipopt' solver is not available")
+class TestReactorDesign(unittest.TestCase):
+    def setUp(self):
+        from pyomo.contrib.parmest.examples.reactor_design.reactor_design import (
+            ReactorDesignExperiment,
+        )
+
+        # Data from the design
+        data = pd.DataFrame(
+            data=[
+                [1.05, 10000, 3458.4, 1060.8, 1683.9, 1898.5],
+                [1.10, 10000, 3535.1, 1064.8, 1613.3, 1893.4],
+                [1.15, 10000, 3609.1, 1067.8, 1547.5, 1887.8],
+                [1.20, 10000, 3680.7, 1070.0, 1486.1, 1881.6],
+                [1.25, 10000, 3750.0, 1071.4, 1428.6, 1875.0],
+                [1.30, 10000, 3817.1, 1072.2, 1374.6, 1868.0],
+                [1.35, 10000, 3882.2, 1072.4, 1324.0, 1860.7],
+                [1.40, 10000, 3945.4, 1072.1, 1276.3, 1853.1],
+                [1.45, 10000, 4006.7, 1071.3, 1231.4, 1845.3],
+                [1.50, 10000, 4066.4, 1070.1, 1189.0, 1837.3],
+                [1.55, 10000, 4124.4, 1068.5, 1148.9, 1829.1],
+                [1.60, 10000, 4180.9, 1066.5, 1111.0, 1820.8],
+                [1.65, 10000, 4235.9, 1064.3, 1075.0, 1812.4],
+                [1.70, 10000, 4289.5, 1061.8, 1040.9, 1803.9],
+                [1.75, 10000, 4341.8, 1059.0, 1008.5, 1795.3],
+                [1.80, 10000, 4392.8, 1056.0, 977.7, 1786.7],
+                [1.85, 10000, 4442.6, 1052.8, 948.4, 1778.1],
+                [1.90, 10000, 4491.3, 1049.4, 920.5, 1769.4],
+                [1.95, 10000, 4538.8, 1045.8, 893.9, 1760.8],
+            ],
+            columns=["sv", "caf", "ca", "cb", "cc", "cd"],
+        )
+
+        # Create an experiment list
+        exp_list = []
+        for i in range(data.shape[0]):
+            exp_list.append(ReactorDesignExperiment(data, i))
+
+        solver_options = {"max_iter": 6000}
+
+        self.pest = parmest.Estimator(
+            exp_list, obj_function="SSE", solver_options=solver_options
+        )
+
+    def test_theta_est(self):
+        # used in data reconciliation
+        objval, thetavals = self.pest.theta_est()
+
+        self.assertAlmostEqual(thetavals["k1"], 5.0 / 6.0, places=4)
+        self.assertAlmostEqual(thetavals["k2"], 5.0 / 3.0, places=4)
+        self.assertAlmostEqual(thetavals["k3"], 1.0 / 6000.0, places=7)
+
+    def test_return_values(self):
+        objval, thetavals, data_rec = self.pest.theta_est(
+            return_values=["ca", "cb", "cc", "cd", "caf"]
+        )
+        self.assertAlmostEqual(data_rec["cc"].loc[18], 893.84924, places=3)
+
+
+@unittest.skipIf(
+    not parmest.parmest_available,
+    "Cannot test parmest: required dependencies are missing",
+)
+@unittest.skipIf(not ipopt_available, "The 'ipopt' solver is not available")
+class TestReactorDesign_DAE(unittest.TestCase):
+    # Based on a reactor example in `Chemical Reactor Analysis and Design Fundamentals`,
+    # https://sites.engineering.ucsb.edu/~jbraw/chemreacfun/
+    # https://sites.engineering.ucsb.edu/~jbraw/chemreacfun/fig-html/appendix/fig-A-10.html
+
+    def setUp(self):
+        def ABC_model(data):
+            ca_meas = data["ca"]
+            cb_meas = data["cb"]
+            cc_meas = data["cc"]
+
+            if isinstance(data, pd.DataFrame):
+                meas_t = data.index  # time index
+            else:  # dictionary
+                meas_t = list(ca_meas.keys())  # nested dictionary
+
+            ca0 = 1.0
+            cb0 = 0.0
+            cc0 = 0.0
+
+            m = pyo.ConcreteModel()
+
+            m.k1 = pyo.Var(initialize=0.5, bounds=(1e-4, 10))
+            m.k2 = pyo.Var(initialize=3.0, bounds=(1e-4, 10))
+
+            m.time = dae.ContinuousSet(bounds=(0.0, 5.0), initialize=meas_t)
+
+            # initialization and bounds
+            m.ca = pyo.Var(m.time, initialize=ca0, bounds=(-1e-3, ca0 + 1e-3))
+            m.cb = pyo.Var(m.time, initialize=cb0, bounds=(-1e-3, ca0 + 1e-3))
+            m.cc = pyo.Var(m.time, initialize=cc0, bounds=(-1e-3, ca0 + 1e-3))
+
+            m.dca = dae.DerivativeVar(m.ca, wrt=m.time)
+            m.dcb = dae.DerivativeVar(m.cb, wrt=m.time)
+            m.dcc = dae.DerivativeVar(m.cc, wrt=m.time)
+
+            def _dcarate(m, t):
+                if t == 0:
+                    return pyo.Constraint.Skip
+                else:
+                    return m.dca[t] == -m.k1 * m.ca[t]
+
+            m.dcarate = pyo.Constraint(m.time, rule=_dcarate)
+
+            def _dcbrate(m, t):
+                if t == 0:
+                    return pyo.Constraint.Skip
+                else:
+                    return m.dcb[t] == m.k1 * m.ca[t] - m.k2 * m.cb[t]
+
+            m.dcbrate = pyo.Constraint(m.time, rule=_dcbrate)
+
+            def _dccrate(m, t):
+                if t == 0:
+                    return pyo.Constraint.Skip
+                else:
+                    return m.dcc[t] == m.k2 * m.cb[t]
+
+            m.dccrate = pyo.Constraint(m.time, rule=_dccrate)
+
+            def ComputeFirstStageCost_rule(m):
+                return 0
+
+            m.FirstStageCost = pyo.Expression(rule=ComputeFirstStageCost_rule)
+
+            def ComputeSecondStageCost_rule(m):
+                return sum(
+                    (m.ca[t] - ca_meas[t]) ** 2
+                    + (m.cb[t] - cb_meas[t]) ** 2
+                    + (m.cc[t] - cc_meas[t]) ** 2
+                    for t in meas_t
+                )
+
+            m.SecondStageCost = pyo.Expression(rule=ComputeSecondStageCost_rule)
+
+            def total_cost_rule(model):
+                return model.FirstStageCost + model.SecondStageCost
+
+            m.Total_Cost_Objective = pyo.Objective(
+                rule=total_cost_rule, sense=pyo.minimize
+            )
+
+            disc = pyo.TransformationFactory("dae.collocation")
+            disc.apply_to(m, nfe=20, ncp=2)
+
+            return m
+
+        class ReactorDesignExperimentDAE(Experiment):
+
+            def __init__(self, data):
+
+                self.data = data
+                self.model = None
+
+            def create_model(self):
+                self.model = ABC_model(self.data)
+
+            def label_model(self):
+
+                m = self.model
+
+                m.unknown_parameters = pyo.Suffix(direction=pyo.Suffix.LOCAL)
+                m.unknown_parameters.update(
+                    (k, pyo.ComponentUID(k)) for k in [m.k1, m.k2]
+                )
+
+            def get_labeled_model(self):
+                self.create_model()
+                self.label_model()
+
+                return self.model
+
+        # This example tests data formatted in 3 ways
+        # Each format holds 1 scenario
+        # 1. dataframe with time index
+        # 2. nested dictionary {ca: {t, val pairs}, ... }
+        data = [
+            [0.000, 0.957, -0.031, -0.015],
+            [0.263, 0.557, 0.330, 0.044],
+            [0.526, 0.342, 0.512, 0.156],
+            [0.789, 0.224, 0.499, 0.310],
+            [1.053, 0.123, 0.428, 0.454],
+            [1.316, 0.079, 0.396, 0.556],
+            [1.579, 0.035, 0.303, 0.651],
+            [1.842, 0.029, 0.287, 0.658],
+            [2.105, 0.025, 0.221, 0.750],
+            [2.368, 0.017, 0.148, 0.854],
+            [2.632, -0.002, 0.182, 0.845],
+            [2.895, 0.009, 0.116, 0.893],
+            [3.158, -0.023, 0.079, 0.942],
+            [3.421, 0.006, 0.078, 0.899],
+            [3.684, 0.016, 0.059, 0.942],
+            [3.947, 0.014, 0.036, 0.991],
+            [4.211, -0.009, 0.014, 0.988],
+            [4.474, -0.030, 0.036, 0.941],
+            [4.737, 0.004, 0.036, 0.971],
+            [5.000, -0.024, 0.028, 0.985],
+        ]
+        data = pd.DataFrame(data, columns=["t", "ca", "cb", "cc"])
+        data_df = data.set_index("t")
+        data_dict = {
+            "ca": {k: v for (k, v) in zip(data.t, data.ca)},
+            "cb": {k: v for (k, v) in zip(data.t, data.cb)},
+            "cc": {k: v for (k, v) in zip(data.t, data.cc)},
+        }
+
+        # Create an experiment list
+        exp_list_df = [ReactorDesignExperimentDAE(data_df)]
+        exp_list_dict = [ReactorDesignExperimentDAE(data_dict)]
+
+        self.pest_df = parmest.Estimator(exp_list_df)
+        self.pest_dict = parmest.Estimator(exp_list_dict)
+
+        # Estimator object with multiple scenarios
+        exp_list_df_multiple = [
+            ReactorDesignExperimentDAE(data_df),
+            ReactorDesignExperimentDAE(data_df),
+        ]
+        exp_list_dict_multiple = [
+            ReactorDesignExperimentDAE(data_dict),
+            ReactorDesignExperimentDAE(data_dict),
+        ]
+
+        self.pest_df_multiple = parmest.Estimator(exp_list_df_multiple)
+        self.pest_dict_multiple = parmest.Estimator(exp_list_dict_multiple)
+
+        # Create an instance of the model
+        self.m_df = ABC_model(data_df)
+        self.m_dict = ABC_model(data_dict)
+
+    def test_dataformats(self):
+        obj1, theta1 = self.pest_df.theta_est()
+        obj2, theta2 = self.pest_dict.theta_est()
+
+        self.assertAlmostEqual(obj1, obj2, places=6)
+        self.assertAlmostEqual(theta1["k1"], theta2["k1"], places=6)
+        self.assertAlmostEqual(theta1["k2"], theta2["k2"], places=6)
+
+    def test_return_continuous_set(self):
+        """
+        test if ContinuousSet elements are returned correctly from theta_est()
+        """
+        obj1, theta1, return_vals1 = self.pest_df.theta_est(return_values=["time"])
+        obj2, theta2, return_vals2 = self.pest_dict.theta_est(return_values=["time"])
+        self.assertAlmostEqual(return_vals1["time"].loc[0][18], 2.368, places=3)
+        self.assertAlmostEqual(return_vals2["time"].loc[0][18], 2.368, places=3)
+
+    def test_return_continuous_set_multiple_datasets(self):
+        """
+        test if ContinuousSet elements are returned correctly from theta_est()
+        """
+        obj1, theta1, return_vals1 = self.pest_df_multiple.theta_est(
+            return_values=["time"]
+        )
+        obj2, theta2, return_vals2 = self.pest_dict_multiple.theta_est(
+            return_values=["time"]
+        )
+        self.assertAlmostEqual(return_vals1["time"].loc[1][18], 2.368, places=3)
+        self.assertAlmostEqual(return_vals2["time"].loc[1][18], 2.368, places=3)
+
+    def test_covariance(self):
+        from pyomo.contrib.interior_point.inverse_reduced_hessian import (
+            inv_reduced_hessian_barrier,
+        )
+
+        # Number of datapoints.
+        # 3 data components (ca, cb, cc), 20 timesteps, 1 scenario = 60
+        # In this example, this is the number of data points in data_df, but that's
+        # only because the data is indexed by time and contains no additional information.
+        n = 60
+
+        # Compute covariance using parmest
+        obj, theta, cov = self.pest_df.theta_est(calc_cov=True, cov_n=n)
+
+        # Compute covariance using interior_point
+        vars_list = [self.m_df.k1, self.m_df.k2]
+        solve_result, inv_red_hes = inv_reduced_hessian_barrier(
+            self.m_df, independent_variables=vars_list, tee=True
+        )
+        l = len(vars_list)
+        cov_interior_point = 2 * obj / (n - l) * inv_red_hes
+        cov_interior_point = pd.DataFrame(
+            cov_interior_point, ["k1", "k2"], ["k1", "k2"]
+        )
+
+        cov_diff = (cov - cov_interior_point).abs().sum().sum()
+
+        self.assertTrue(cov.loc["k1", "k1"] > 0)
+        self.assertTrue(cov.loc["k2", "k2"] > 0)
+        self.assertAlmostEqual(cov_diff, 0, places=6)
+
+
+@unittest.skipIf(
+    not parmest.parmest_available,
+    "Cannot test parmest: required dependencies are missing",
+)
+@unittest.skipIf(not ipopt_available, "The 'ipopt' command is not available")
+class TestSquareInitialization_RooneyBiegler(unittest.TestCase):
+    def setUp(self):
+        from pyomo.contrib.parmest.examples.rooney_biegler.rooney_biegler_with_constraint import (
+            RooneyBieglerExperiment,
+        )
+
+        # Note, the data used in this test has been corrected to use data.loc[5,'hour'] = 7 (instead of 6)
+        data = pd.DataFrame(
+            data=[[1, 8.3], [2, 10.3], [3, 19.0], [4, 16.0], [5, 15.6], [7, 19.8]],
+            columns=["hour", "y"],
+        )
+
+        # Sum of squared error function
+        def SSE(model):
+            expr = (
+                model.experiment_outputs[model.y]
+                - model.response_function[model.experiment_outputs[model.hour]]
+            ) ** 2
+            return expr
+
+        exp_list = []
+        for i in range(data.shape[0]):
+            exp_list.append(RooneyBieglerExperiment(data.loc[i, :]))
+
+        solver_options = {"tol": 1e-8}
+
+        self.data = data
+        self.pest = parmest.Estimator(
+            exp_list, obj_function=SSE, solver_options=solver_options, tee=True
+        )
+
+    def test_theta_est_with_square_initialization(self):
+        obj_init = self.pest.objective_at_theta(initialize_parmest_model=True)
+        objval, thetavals = self.pest.theta_est()
+
+        self.assertAlmostEqual(objval, 4.3317112, places=2)
+        self.assertAlmostEqual(
+            thetavals["asymptote"], 19.1426, places=2
+        )  # 19.1426 from the paper
+        self.assertAlmostEqual(
+            thetavals["rate_constant"], 0.5311, places=2
+        )  # 0.5311 from the paper
+
+    def test_theta_est_with_square_initialization_and_custom_init_theta(self):
+        theta_vals_init = pd.DataFrame(
+            data=[[19.0, 0.5]], columns=["asymptote", "rate_constant"]
+        )
+        obj_init = self.pest.objective_at_theta(
+            theta_values=theta_vals_init, initialize_parmest_model=True
         )
+        objval, thetavals = self.pest.theta_est()
+        self.assertAlmostEqual(objval, 4.3317112, places=2)
+        self.assertAlmostEqual(
+            thetavals["asymptote"], 19.1426, places=2
+        )  # 19.1426 from the paper
+        self.assertAlmostEqual(
+            thetavals["rate_constant"], 0.5311, places=2
+        )  # 0.5311 from the paper
+
+    def test_theta_est_with_square_initialization_diagnostic_mode_true(self):
+        self.pest.diagnostic_mode = True
+        obj_init = self.pest.objective_at_theta(initialize_parmest_model=True)
+        objval, thetavals = self.pest.theta_est()
+
+        self.assertAlmostEqual(objval, 4.3317112, places=2)
+        self.assertAlmostEqual(
+            thetavals["asymptote"], 19.1426, places=2
+        )  # 19.1426 from the paper
+        self.assertAlmostEqual(
+            thetavals["rate_constant"], 0.5311, places=2
+        )  # 0.5311 from the paper
+
+        self.pest.diagnostic_mode = False
+
+
+###########################
+# tests for deprecated UI #
+###########################
+
+
+@unittest.skipIf(
+    not parmest.parmest_available,
+    "Cannot test parmest: required dependencies are missing",
+)
+@unittest.skipIf(not ipopt_available, "The 'ipopt' command is not available")
+class TestRooneyBieglerDeprecated(unittest.TestCase):
+    def setUp(self):
+
+        def rooney_biegler_model(data):
+            model = pyo.ConcreteModel()
+
+            model.asymptote = pyo.Var(initialize=15)
+            model.rate_constant = pyo.Var(initialize=0.5)
+
+            def response_rule(m, h):
+                expr = m.asymptote * (1 - pyo.exp(-m.rate_constant * h))
+                return expr
+
+            model.response_function = pyo.Expression(data.hour, rule=response_rule)
+
+            def SSE_rule(m):
+                return sum(
+                    (data.y[i] - m.response_function[data.hour[i]]) ** 2
+                    for i in data.index
+                )
+
+            model.SSE = pyo.Objective(rule=SSE_rule, sense=pyo.minimize)
+
+            return model
 
         # Note, the data used in this test has been corrected to use data.loc[5,'hour'] = 7 (instead of 6)
         data = pd.DataFrame(
@@ -132,7 +1144,7 @@ def test_likelihood_ratio(self):
         asym = np.arange(10, 30, 2)
         rate = np.arange(0, 1.5, 0.25)
         theta_vals = pd.DataFrame(
-            list(product(asym, rate)), columns=self.pest.theta_names
+            list(product(asym, rate)), columns=self.pest._return_theta_names()
         )
 
         obj_at_theta = self.pest.objective_at_theta(theta_vals)
@@ -173,7 +1185,7 @@ def test_diagnostic_mode(self):
         asym = np.arange(10, 30, 2)
         rate = np.arange(0, 1.5, 0.25)
         theta_vals = pd.DataFrame(
-            list(product(asym, rate)), columns=self.pest.theta_names
+            list(product(asym, rate)), columns=self.pest._return_theta_names()
         )
 
         obj_at_theta = self.pest.objective_at_theta(theta_vals)
@@ -347,7 +1359,7 @@ def model(t, asymptote, rate_constant):
     "Cannot test parmest: required dependencies are missing",
 )
 @unittest.skipIf(not ipopt_available, "The 'ipopt' command is not available")
-class TestModelVariants(unittest.TestCase):
+class TestModelVariantsDeprecated(unittest.TestCase):
     def setUp(self):
         self.data = pd.DataFrame(
             data=[[1, 8.3], [2, 10.3], [3, 19.0], [4, 16.0], [5, 15.6], [7, 19.8]],
@@ -601,11 +1613,84 @@ def test_parmest_basics_with_square_problem_solve_no_theta_vals(self):
     "Cannot test parmest: required dependencies are missing",
 )
 @unittest.skipIf(not ipopt_available, "The 'ipopt' solver is not available")
-class TestReactorDesign(unittest.TestCase):
+class TestReactorDesignDeprecated(unittest.TestCase):
     def setUp(self):
-        from pyomo.contrib.parmest.examples.reactor_design.reactor_design import (
-            reactor_design_model,
-        )
+
+        def reactor_design_model(data):
+            # Create the concrete model
+            model = pyo.ConcreteModel()
+
+            # Rate constants
+            model.k1 = pyo.Param(
+                initialize=5.0 / 6.0, within=pyo.PositiveReals, mutable=True
+            )  # min^-1
+            model.k2 = pyo.Param(
+                initialize=5.0 / 3.0, within=pyo.PositiveReals, mutable=True
+            )  # min^-1
+            model.k3 = pyo.Param(
+                initialize=1.0 / 6000.0, within=pyo.PositiveReals, mutable=True
+            )  # m^3/(gmol min)
+
+            # Inlet concentration of A, gmol/m^3
+            if isinstance(data, dict) or isinstance(data, pd.Series):
+                model.caf = pyo.Param(
+                    initialize=float(data["caf"]), within=pyo.PositiveReals
+                )
+            elif isinstance(data, pd.DataFrame):
+                model.caf = pyo.Param(
+                    initialize=float(data.iloc[0]["caf"]), within=pyo.PositiveReals
+                )
+            else:
+                raise ValueError("Unrecognized data type.")
+
+            # Space velocity (flowrate/volume)
+            if isinstance(data, dict) or isinstance(data, pd.Series):
+                model.sv = pyo.Param(
+                    initialize=float(data["sv"]), within=pyo.PositiveReals
+                )
+            elif isinstance(data, pd.DataFrame):
+                model.sv = pyo.Param(
+                    initialize=float(data.iloc[0]["sv"]), within=pyo.PositiveReals
+                )
+            else:
+                raise ValueError("Unrecognized data type.")
+
+            # Outlet concentration of each component
+            model.ca = pyo.Var(initialize=5000.0, within=pyo.PositiveReals)
+            model.cb = pyo.Var(initialize=2000.0, within=pyo.PositiveReals)
+            model.cc = pyo.Var(initialize=2000.0, within=pyo.PositiveReals)
+            model.cd = pyo.Var(initialize=1000.0, within=pyo.PositiveReals)
+
+            # Objective
+            model.obj = pyo.Objective(expr=model.cb, sense=pyo.maximize)
+
+            # Constraints
+            model.ca_bal = pyo.Constraint(
+                expr=(
+                    0
+                    == model.sv * model.caf
+                    - model.sv * model.ca
+                    - model.k1 * model.ca
+                    - 2.0 * model.k3 * model.ca**2.0
+                )
+            )
+
+            model.cb_bal = pyo.Constraint(
+                expr=(
+                    0
+                    == -model.sv * model.cb + model.k1 * model.ca - model.k2 * model.cb
+                )
+            )
+
+            model.cc_bal = pyo.Constraint(
+                expr=(0 == -model.sv * model.cc + model.k2 * model.cb)
+            )
+
+            model.cd_bal = pyo.Constraint(
+                expr=(0 == -model.sv * model.cd + model.k3 * model.ca**2.0)
+            )
+
+            return model
 
         # Data from the design
         data = pd.DataFrame(
@@ -670,7 +1755,7 @@ def test_return_values(self):
     "Cannot test parmest: required dependencies are missing",
 )
 @unittest.skipIf(not ipopt_available, "The 'ipopt' solver is not available")
-class TestReactorDesign_DAE(unittest.TestCase):
+class TestReactorDesign_DAE_Deprecated(unittest.TestCase):
     # Based on a reactor example in `Chemical Reactor Analysis and Design Fundamentals`,
     # https://sites.engineering.ucsb.edu/~jbraw/chemreacfun/
     # https://sites.engineering.ucsb.edu/~jbraw/chemreacfun/fig-html/appendix/fig-A-10.html
@@ -875,11 +1960,35 @@ def test_covariance(self):
     "Cannot test parmest: required dependencies are missing",
 )
 @unittest.skipIf(not ipopt_available, "The 'ipopt' command is not available")
-class TestSquareInitialization_RooneyBiegler(unittest.TestCase):
+class TestSquareInitialization_RooneyBiegler_Deprecated(unittest.TestCase):
     def setUp(self):
-        from pyomo.contrib.parmest.examples.rooney_biegler.rooney_biegler_with_constraint import (
-            rooney_biegler_model_with_constraint,
-        )
+
+        def rooney_biegler_model_with_constraint(data):
+            model = pyo.ConcreteModel()
+
+            model.asymptote = pyo.Var(initialize=15)
+            model.rate_constant = pyo.Var(initialize=0.5)
+            model.response_function = pyo.Var(data.hour, initialize=0.0)
+
+            # changed from expression to constraint
+            def response_rule(m, h):
+                return m.response_function[h] == m.asymptote * (
+                    1 - pyo.exp(-m.rate_constant * h)
+                )
+
+            model.response_function_constraint = pyo.Constraint(
+                data.hour, rule=response_rule
+            )
+
+            def SSE_rule(m):
+                return sum(
+                    (data.y[i] - m.response_function[data.hour[i]]) ** 2
+                    for i in data.index
+                )
+
+            model.SSE = pyo.Objective(rule=SSE_rule, sense=pyo.minimize)
+
+            return model
 
         # Note, the data used in this test has been corrected to use data.loc[5,'hour'] = 7 (instead of 6)
         data = pd.DataFrame(
diff --git a/pyomo/contrib/parmest/tests/test_scenariocreator.py b/pyomo/contrib/parmest/tests/test_scenariocreator.py
index 22a851ae32e..af755e34b67 100644
--- a/pyomo/contrib/parmest/tests/test_scenariocreator.py
+++ b/pyomo/contrib/parmest/tests/test_scenariocreator.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -37,7 +37,7 @@
 class TestScenarioReactorDesign(unittest.TestCase):
     def setUp(self):
         from pyomo.contrib.parmest.examples.reactor_design.reactor_design import (
-            reactor_design_model,
+            ReactorDesignExperiment,
         )
 
         # Data from the design
@@ -66,6 +66,193 @@ def setUp(self):
             columns=["sv", "caf", "ca", "cb", "cc", "cd"],
         )
 
+        # Create an experiment list
+        exp_list = []
+        for i in range(data.shape[0]):
+            exp_list.append(ReactorDesignExperiment(data, i))
+
+        self.pest = parmest.Estimator(exp_list, obj_function='SSE')
+
+    def test_scen_from_exps(self):
+        scenmaker = sc.ScenarioCreator(self.pest, "ipopt")
+        experimentscens = sc.ScenarioSet("Experiments")
+        scenmaker.ScenariosFromExperiments(experimentscens)
+        experimentscens.write_csv("delme_exp_csv.csv")
+        df = pd.read_csv("delme_exp_csv.csv")
+        os.remove("delme_exp_csv.csv")
+        # March '20: all reactor_design experiments have the same theta values!
+        k1val = df.loc[5].at["k1"]
+        self.assertAlmostEqual(k1val, 5.0 / 6.0, places=2)
+        tval = experimentscens.ScenarioNumber(0).ThetaVals["k1"]
+        self.assertAlmostEqual(tval, 5.0 / 6.0, places=2)
+
+    @unittest.skipIf(not uuid_available, "The uuid module is not available")
+    def test_no_csv_if_empty(self):
+        # low level test of scenario sets
+        # verify that nothing is written, but no errors with empty set
+
+        emptyset = sc.ScenarioSet("empty")
+        tfile = uuid.uuid4().hex + ".csv"
+        emptyset.write_csv(tfile)
+        self.assertFalse(
+            os.path.exists(tfile), "ScenarioSet wrote csv in spite of empty set"
+        )
+
+
+@unittest.skipIf(
+    not parmest.parmest_available,
+    "Cannot test parmest: required dependencies are missing",
+)
+@unittest.skipIf(not ipopt_available, "The 'ipopt' command is not available")
+class TestScenarioSemibatch(unittest.TestCase):
+    def setUp(self):
+        import pyomo.contrib.parmest.examples.semibatch.semibatch as sb
+        import json
+
+        self.fbase = os.path.join(testdir, "..", "examples", "semibatch")
+        # Data, list of dictionaries
+        data = []
+        for exp_num in range(10):
+            fname = "exp" + str(exp_num + 1) + ".out"
+            fullname = os.path.join(self.fbase, fname)
+            with open(fullname, "r") as infile:
+                d = json.load(infile)
+                data.append(d)
+
+        # Note, the model already includes a 'SecondStageCost' expression
+        # for the sum of squared error that will be used in parameter estimation
+
+        # Create an experiment list
+        exp_list = []
+        for i in range(len(data)):
+            exp_list.append(sb.SemiBatchExperiment(data[i]))
+
+        self.pest = parmest.Estimator(exp_list)
+
+    def test_semibatch_bootstrap(self):
+        scenmaker = sc.ScenarioCreator(self.pest, "ipopt")
+        bootscens = sc.ScenarioSet("Bootstrap")
+        numtomake = 2
+        scenmaker.ScenariosFromBootstrap(bootscens, numtomake, seed=1134)
+        tval = bootscens.ScenarioNumber(0).ThetaVals["k1"]
+        self.assertAlmostEqual(tval, 20.64, places=1)
+
+
+###########################
+# tests for deprecated UI #
+###########################
+
+
+@unittest.skipIf(
+    not parmest.parmest_available,
+    "Cannot test parmest: required dependencies are missing",
+)
+@unittest.skipIf(not ipopt_available, "The 'ipopt' command is not available")
+class TestScenarioReactorDesignDeprecated(unittest.TestCase):
+    def setUp(self):
+
+        def reactor_design_model(data):
+            # Create the concrete model
+            model = pyo.ConcreteModel()
+
+            # Rate constants
+            model.k1 = pyo.Param(
+                initialize=5.0 / 6.0, within=pyo.PositiveReals, mutable=True
+            )  # min^-1
+            model.k2 = pyo.Param(
+                initialize=5.0 / 3.0, within=pyo.PositiveReals, mutable=True
+            )  # min^-1
+            model.k3 = pyo.Param(
+                initialize=1.0 / 6000.0, within=pyo.PositiveReals, mutable=True
+            )  # m^3/(gmol min)
+
+            # Inlet concentration of A, gmol/m^3
+            if isinstance(data, dict) or isinstance(data, pd.Series):
+                model.caf = pyo.Param(
+                    initialize=float(data["caf"]), within=pyo.PositiveReals
+                )
+            elif isinstance(data, pd.DataFrame):
+                model.caf = pyo.Param(
+                    initialize=float(data.iloc[0]["caf"]), within=pyo.PositiveReals
+                )
+            else:
+                raise ValueError("Unrecognized data type.")
+
+            # Space velocity (flowrate/volume)
+            if isinstance(data, dict) or isinstance(data, pd.Series):
+                model.sv = pyo.Param(
+                    initialize=float(data["sv"]), within=pyo.PositiveReals
+                )
+            elif isinstance(data, pd.DataFrame):
+                model.sv = pyo.Param(
+                    initialize=float(data.iloc[0]["sv"]), within=pyo.PositiveReals
+                )
+            else:
+                raise ValueError("Unrecognized data type.")
+
+            # Outlet concentration of each component
+            model.ca = pyo.Var(initialize=5000.0, within=pyo.PositiveReals)
+            model.cb = pyo.Var(initialize=2000.0, within=pyo.PositiveReals)
+            model.cc = pyo.Var(initialize=2000.0, within=pyo.PositiveReals)
+            model.cd = pyo.Var(initialize=1000.0, within=pyo.PositiveReals)
+
+            # Objective
+            model.obj = pyo.Objective(expr=model.cb, sense=pyo.maximize)
+
+            # Constraints
+            model.ca_bal = pyo.Constraint(
+                expr=(
+                    0
+                    == model.sv * model.caf
+                    - model.sv * model.ca
+                    - model.k1 * model.ca
+                    - 2.0 * model.k3 * model.ca**2.0
+                )
+            )
+
+            model.cb_bal = pyo.Constraint(
+                expr=(
+                    0
+                    == -model.sv * model.cb + model.k1 * model.ca - model.k2 * model.cb
+                )
+            )
+
+            model.cc_bal = pyo.Constraint(
+                expr=(0 == -model.sv * model.cc + model.k2 * model.cb)
+            )
+
+            model.cd_bal = pyo.Constraint(
+                expr=(0 == -model.sv * model.cd + model.k3 * model.ca**2.0)
+            )
+
+            return model
+
+        # Data from the design
+        data = pd.DataFrame(
+            data=[
+                [1.05, 10000, 3458.4, 1060.8, 1683.9, 1898.5],
+                [1.10, 10000, 3535.1, 1064.8, 1613.3, 1893.4],
+                [1.15, 10000, 3609.1, 1067.8, 1547.5, 1887.8],
+                [1.20, 10000, 3680.7, 1070.0, 1486.1, 1881.6],
+                [1.25, 10000, 3750.0, 1071.4, 1428.6, 1875.0],
+                [1.30, 10000, 3817.1, 1072.2, 1374.6, 1868.0],
+                [1.35, 10000, 3882.2, 1072.4, 1324.0, 1860.7],
+                [1.40, 10000, 3945.4, 1072.1, 1276.3, 1853.1],
+                [1.45, 10000, 4006.7, 1071.3, 1231.4, 1845.3],
+                [1.50, 10000, 4066.4, 1070.1, 1189.0, 1837.3],
+                [1.55, 10000, 4124.4, 1068.5, 1148.9, 1829.1],
+                [1.60, 10000, 4180.9, 1066.5, 1111.0, 1820.8],
+                [1.65, 10000, 4235.9, 1064.3, 1075.0, 1812.4],
+                [1.70, 10000, 4289.5, 1061.8, 1040.9, 1803.9],
+                [1.75, 10000, 4341.8, 1059.0, 1008.5, 1795.3],
+                [1.80, 10000, 4392.8, 1056.0, 977.7, 1786.7],
+                [1.85, 10000, 4442.6, 1052.8, 948.4, 1778.1],
+                [1.90, 10000, 4491.3, 1049.4, 920.5, 1769.4],
+                [1.95, 10000, 4538.8, 1045.8, 893.9, 1760.8],
+            ],
+            columns=["sv", "caf", "ca", "cb", "cc", "cd"],
+        )
+
         theta_names = ["k1", "k2", "k3"]
 
         def SSE(model, data):
@@ -110,10 +297,267 @@ def test_no_csv_if_empty(self):
     "Cannot test parmest: required dependencies are missing",
 )
 @unittest.skipIf(not ipopt_available, "The 'ipopt' command is not available")
-class TestScenarioSemibatch(unittest.TestCase):
+class TestScenarioSemibatchDeprecated(unittest.TestCase):
     def setUp(self):
-        import pyomo.contrib.parmest.examples.semibatch.semibatch as sb
+
         import json
+        from pyomo.environ import (
+            ConcreteModel,
+            Set,
+            Param,
+            Var,
+            Constraint,
+            ConstraintList,
+            Expression,
+            Objective,
+            TransformationFactory,
+            SolverFactory,
+            exp,
+            minimize,
+        )
+        from pyomo.dae import ContinuousSet, DerivativeVar
+
+        def generate_model(data):
+            # if data is a file name, then load file first
+            if isinstance(data, str):
+                file_name = data
+                try:
+                    with open(file_name, "r") as infile:
+                        data = json.load(infile)
+                except:
+                    raise RuntimeError(f"Could not read {file_name} as json")
+
+            # unpack and fix the data
+            cameastemp = data["Ca_meas"]
+            cbmeastemp = data["Cb_meas"]
+            ccmeastemp = data["Cc_meas"]
+            trmeastemp = data["Tr_meas"]
+
+            cameas = {}
+            cbmeas = {}
+            ccmeas = {}
+            trmeas = {}
+            for i in cameastemp.keys():
+                cameas[float(i)] = cameastemp[i]
+                cbmeas[float(i)] = cbmeastemp[i]
+                ccmeas[float(i)] = ccmeastemp[i]
+                trmeas[float(i)] = trmeastemp[i]
+
+            m = ConcreteModel()
+
+            #
+            # Measurement Data
+            #
+            m.measT = Set(initialize=sorted(cameas.keys()))
+            m.Ca_meas = Param(m.measT, initialize=cameas)
+            m.Cb_meas = Param(m.measT, initialize=cbmeas)
+            m.Cc_meas = Param(m.measT, initialize=ccmeas)
+            m.Tr_meas = Param(m.measT, initialize=trmeas)
+
+            #
+            # Parameters for semi-batch reactor model
+            #
+            m.R = Param(initialize=8.314)  # kJ/kmol/K
+            m.Mwa = Param(initialize=50.0)  # kg/kmol
+            m.rhor = Param(initialize=1000.0)  # kg/m^3
+            m.cpr = Param(initialize=3.9)  # kJ/kg/K
+            m.Tf = Param(initialize=300)  # K
+            m.deltaH1 = Param(initialize=-40000.0)  # kJ/kmol
+            m.deltaH2 = Param(initialize=-50000.0)  # kJ/kmol
+            m.alphaj = Param(initialize=0.8)  # kJ/s/m^2/K
+            m.alphac = Param(initialize=0.7)  # kJ/s/m^2/K
+            m.Aj = Param(initialize=5.0)  # m^2
+            m.Ac = Param(initialize=3.0)  # m^2
+            m.Vj = Param(initialize=0.9)  # m^3
+            m.Vc = Param(initialize=0.07)  # m^3
+            m.rhow = Param(initialize=700.0)  # kg/m^3
+            m.cpw = Param(initialize=3.1)  # kJ/kg/K
+            m.Ca0 = Param(initialize=data["Ca0"])  # kmol/m^3)
+            m.Cb0 = Param(initialize=data["Cb0"])  # kmol/m^3)
+            m.Cc0 = Param(initialize=data["Cc0"])  # kmol/m^3)
+            m.Tr0 = Param(initialize=300.0)  # K
+            m.Vr0 = Param(initialize=1.0)  # m^3
+
+            m.time = ContinuousSet(
+                bounds=(0, 21600), initialize=m.measT
+            )  # Time in seconds
+
+            #
+            # Control Inputs
+            #
+            def _initTc(m, t):
+                if t < 10800:
+                    return data["Tc1"]
+                else:
+                    return data["Tc2"]
+
+            m.Tc = Param(
+                m.time, initialize=_initTc, default=_initTc
+            )  # bounds= (288,432) Cooling coil temp, control input
+
+            def _initFa(m, t):
+                if t < 10800:
+                    return data["Fa1"]
+                else:
+                    return data["Fa2"]
+
+            m.Fa = Param(
+                m.time, initialize=_initFa, default=_initFa
+            )  # bounds=(0,0.05) Inlet flow rate, control input
+
+            #
+            # Parameters being estimated
+            #
+            m.k1 = Var(initialize=14, bounds=(2, 100))  # 1/s Actual: 15.01
+            m.k2 = Var(initialize=90, bounds=(2, 150))  # 1/s Actual: 85.01
+            m.E1 = Var(
+                initialize=27000.0, bounds=(25000, 40000)
+            )  # kJ/kmol Actual: 30000
+            m.E2 = Var(
+                initialize=45000.0, bounds=(35000, 50000)
+            )  # kJ/kmol Actual: 40000
+            # m.E1.fix(30000)
+            # m.E2.fix(40000)
+
+            #
+            # Time dependent variables
+            #
+            m.Ca = Var(m.time, initialize=m.Ca0, bounds=(0, 25))
+            m.Cb = Var(m.time, initialize=m.Cb0, bounds=(0, 25))
+            m.Cc = Var(m.time, initialize=m.Cc0, bounds=(0, 25))
+            m.Vr = Var(m.time, initialize=m.Vr0)
+            m.Tr = Var(m.time, initialize=m.Tr0)
+            m.Tj = Var(
+                m.time, initialize=310.0, bounds=(288, None)
+            )  # Cooling jacket temp, follows coil temp until failure
+
+            #
+            # Derivatives in the model
+            #
+            m.dCa = DerivativeVar(m.Ca)
+            m.dCb = DerivativeVar(m.Cb)
+            m.dCc = DerivativeVar(m.Cc)
+            m.dVr = DerivativeVar(m.Vr)
+            m.dTr = DerivativeVar(m.Tr)
+
+            #
+            # Differential Equations in the model
+            #
+
+            def _dCacon(m, t):
+                if t == 0:
+                    return Constraint.Skip
+                return (
+                    m.dCa[t]
+                    == m.Fa[t] / m.Vr[t] - m.k1 * exp(-m.E1 / (m.R * m.Tr[t])) * m.Ca[t]
+                )
+
+            m.dCacon = Constraint(m.time, rule=_dCacon)
+
+            def _dCbcon(m, t):
+                if t == 0:
+                    return Constraint.Skip
+                return (
+                    m.dCb[t]
+                    == m.k1 * exp(-m.E1 / (m.R * m.Tr[t])) * m.Ca[t]
+                    - m.k2 * exp(-m.E2 / (m.R * m.Tr[t])) * m.Cb[t]
+                )
+
+            m.dCbcon = Constraint(m.time, rule=_dCbcon)
+
+            def _dCccon(m, t):
+                if t == 0:
+                    return Constraint.Skip
+                return m.dCc[t] == m.k2 * exp(-m.E2 / (m.R * m.Tr[t])) * m.Cb[t]
+
+            m.dCccon = Constraint(m.time, rule=_dCccon)
+
+            def _dVrcon(m, t):
+                if t == 0:
+                    return Constraint.Skip
+                return m.dVr[t] == m.Fa[t] * m.Mwa / m.rhor
+
+            m.dVrcon = Constraint(m.time, rule=_dVrcon)
+
+            def _dTrcon(m, t):
+                if t == 0:
+                    return Constraint.Skip
+                return m.rhor * m.cpr * m.dTr[t] == m.Fa[t] * m.Mwa * m.cpr / m.Vr[
+                    t
+                ] * (m.Tf - m.Tr[t]) - m.k1 * exp(-m.E1 / (m.R * m.Tr[t])) * m.Ca[
+                    t
+                ] * m.deltaH1 - m.k2 * exp(
+                    -m.E2 / (m.R * m.Tr[t])
+                ) * m.Cb[
+                    t
+                ] * m.deltaH2 + m.alphaj * m.Aj / m.Vr0 * (
+                    m.Tj[t] - m.Tr[t]
+                ) + m.alphac * m.Ac / m.Vr0 * (
+                    m.Tc[t] - m.Tr[t]
+                )
+
+            m.dTrcon = Constraint(m.time, rule=_dTrcon)
+
+            def _singlecooling(m, t):
+                return m.Tc[t] == m.Tj[t]
+
+            m.singlecooling = Constraint(m.time, rule=_singlecooling)
+
+            # Initial Conditions
+            def _initcon(m):
+                yield m.Ca[m.time.first()] == m.Ca0
+                yield m.Cb[m.time.first()] == m.Cb0
+                yield m.Cc[m.time.first()] == m.Cc0
+                yield m.Vr[m.time.first()] == m.Vr0
+                yield m.Tr[m.time.first()] == m.Tr0
+
+            m.initcon = ConstraintList(rule=_initcon)
+
+            #
+            # Stage-specific cost computations
+            #
+            def ComputeFirstStageCost_rule(model):
+                return 0
+
+            m.FirstStageCost = Expression(rule=ComputeFirstStageCost_rule)
+
+            def AllMeasurements(m):
+                return sum(
+                    (m.Ca[t] - m.Ca_meas[t]) ** 2
+                    + (m.Cb[t] - m.Cb_meas[t]) ** 2
+                    + (m.Cc[t] - m.Cc_meas[t]) ** 2
+                    + 0.01 * (m.Tr[t] - m.Tr_meas[t]) ** 2
+                    for t in m.measT
+                )
+
+            def MissingMeasurements(m):
+                if data["experiment"] == 1:
+                    return sum(
+                        (m.Ca[t] - m.Ca_meas[t]) ** 2
+                        + (m.Cb[t] - m.Cb_meas[t]) ** 2
+                        + (m.Cc[t] - m.Cc_meas[t]) ** 2
+                        + (m.Tr[t] - m.Tr_meas[t]) ** 2
+                        for t in m.measT
+                    )
+                elif data["experiment"] == 2:
+                    return sum((m.Tr[t] - m.Tr_meas[t]) ** 2 for t in m.measT)
+                else:
+                    return sum(
+                        (m.Cb[t] - m.Cb_meas[t]) ** 2 + (m.Tr[t] - m.Tr_meas[t]) ** 2
+                        for t in m.measT
+                    )
+
+            m.SecondStageCost = Expression(rule=MissingMeasurements)
+
+            def total_cost_rule(model):
+                return model.FirstStageCost + model.SecondStageCost
+
+            m.Total_Cost_Objective = Objective(rule=total_cost_rule, sense=minimize)
+
+            # Discretize model
+            disc = TransformationFactory("dae.collocation")
+            disc.apply_to(m, nfe=20, ncp=4)
+            return m
 
         # Vars to estimate in parmest
         theta_names = ["k1", "k2", "E1", "E2"]
@@ -131,7 +575,7 @@ def setUp(self):
         # Note, the model already includes a 'SecondStageCost' expression
         # for the sum of squared error that will be used in parameter estimation
 
-        self.pest = parmest.Estimator(sb.generate_model, data, theta_names)
+        self.pest = parmest.Estimator(generate_model, data, theta_names)
 
     def test_semibatch_bootstrap(self):
         scenmaker = sc.ScenarioCreator(self.pest, "ipopt")
diff --git a/pyomo/contrib/parmest/tests/test_solver.py b/pyomo/contrib/parmest/tests/test_solver.py
index eb655023b9b..77eca3a13b6 100644
--- a/pyomo/contrib/parmest/tests/test_solver.py
+++ b/pyomo/contrib/parmest/tests/test_solver.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/parmest/tests/test_utils.py b/pyomo/contrib/parmest/tests/test_utils.py
index 514c14b1e82..d5e66ab58d5 100644
--- a/pyomo/contrib/parmest/tests/test_utils.py
+++ b/pyomo/contrib/parmest/tests/test_utils.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -25,18 +25,12 @@
 )
 @unittest.skipIf(not ipopt_available, "The 'ipopt' solver is not available")
 class TestUtils(unittest.TestCase):
-    @classmethod
-    def setUpClass(self):
-        pass
 
-    @classmethod
-    def tearDownClass(self):
-        pass
-
-    @unittest.pytest.mark.expensive
     def test_convert_param_to_var(self):
+        # TODO: Check that this works for different structured models (indexed, blocks, etc)
+
         from pyomo.contrib.parmest.examples.reactor_design.reactor_design import (
-            reactor_design_model,
+            ReactorDesignExperiment,
         )
 
         data = pd.DataFrame(
@@ -48,20 +42,23 @@ def test_convert_param_to_var(self):
             columns=["sv", "caf", "ca", "cb", "cc", "cd"],
         )
 
-        theta_names = ["k1", "k2", "k3"]
-
-        instance = reactor_design_model(data.loc[0])
-        solver = pyo.SolverFactory("ipopt")
-        solver.solve(instance)
+        # make model
+        exp = ReactorDesignExperiment(data, 0)
+        instance = exp.get_labeled_model()
 
-        instance_vars = parmest.utils.convert_params_to_vars(
+        theta_names = ['k1', 'k2', 'k3']
+        m_vars = parmest.utils.convert_params_to_vars(
             instance, theta_names, fix_vars=True
         )
-        solver.solve(instance_vars)
 
-        assert instance.k1() == instance_vars.k1()
-        assert instance.k2() == instance_vars.k2()
-        assert instance.k3() == instance_vars.k3()
+        for v in theta_names:
+            self.assertTrue(hasattr(m_vars, v))
+            c = m_vars.find_component(v)
+            self.assertIsInstance(c, pyo.Var)
+            self.assertTrue(c.fixed)
+            c_old = instance.find_component(v)
+            self.assertEqual(pyo.value(c), pyo.value(c_old))
+            self.assertTrue(c in m_vars.unknown_parameters)
 
 
 if __name__ == "__main__":
diff --git a/pyomo/contrib/parmest/utils/__init__.py b/pyomo/contrib/parmest/utils/__init__.py
index 1615ab206f7..3c6900aa5d9 100644
--- a/pyomo/contrib/parmest/utils/__init__.py
+++ b/pyomo/contrib/parmest/utils/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/parmest/utils/create_ef.py b/pyomo/contrib/parmest/utils/create_ef.py
index 2e6c8541fa1..aaadc7f98b9 100644
--- a/pyomo/contrib/parmest/utils/create_ef.py
+++ b/pyomo/contrib/parmest/utils/create_ef.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # This software is distributed under the 3-clause BSD License.
 # Copied with minor modifications from create_EF in mpisppy/utils/sputils.py
 # from the mpi-sppy library (https://github.com/Pyomo/mpi-sppy).
diff --git a/pyomo/contrib/parmest/utils/ipopt_solver_wrapper.py b/pyomo/contrib/parmest/utils/ipopt_solver_wrapper.py
index 7d8289cd181..08388dc5ec1 100644
--- a/pyomo/contrib/parmest/utils/ipopt_solver_wrapper.py
+++ b/pyomo/contrib/parmest/utils/ipopt_solver_wrapper.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/parmest/utils/model_utils.py b/pyomo/contrib/parmest/utils/model_utils.py
index c3c71dc2d6c..7778ebcc9f1 100644
--- a/pyomo/contrib/parmest/utils/model_utils.py
+++ b/pyomo/contrib/parmest/utils/model_utils.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -15,6 +15,7 @@
 from pyomo.core.expr import replace_expressions, identify_mutable_parameters
 from pyomo.core.base.var import IndexedVar
 from pyomo.core.base.param import IndexedParam
+from pyomo.common.collections import ComponentMap
 
 from pyomo.environ import ComponentUID
 
@@ -49,6 +50,7 @@ def convert_params_to_vars(model, param_names=None, fix_vars=False):
 
     # Convert Params to Vars, unfix Vars, and create a substitution map
     substitution_map = {}
+    comp_map = ComponentMap()
     for i, param_name in enumerate(param_names):
         # Leverage the parser in ComponentUID to locate the component.
         theta_cuid = ComponentUID(param_name)
@@ -65,6 +67,7 @@ def convert_params_to_vars(model, param_names=None, fix_vars=False):
             theta_var_cuid = ComponentUID(theta_object.name)
             theta_var_object = theta_var_cuid.find_component_on(model)
             substitution_map[id(theta_object)] = theta_var_object
+            comp_map[theta_object] = theta_var_object
 
         # Indexed Param
         elif isinstance(theta_object, IndexedParam):
@@ -90,6 +93,7 @@ def convert_params_to_vars(model, param_names=None, fix_vars=False):
             # Update substitution map (map each indexed param to indexed var)
             theta_var_cuid = ComponentUID(theta_object.name)
             theta_var_object = theta_var_cuid.find_component_on(model)
+            comp_map[theta_object] = theta_var_object
             var_theta_objects = []
             for theta_obj in theta_var_object:
                 theta_cuid = ComponentUID(
@@ -101,6 +105,7 @@ def convert_params_to_vars(model, param_names=None, fix_vars=False):
                 param_theta_objects, var_theta_objects
             ):
                 substitution_map[id(param_theta_obj)] = var_theta_obj
+                comp_map[param_theta_obj] = var_theta_obj
 
         # Var or Indexed Var
         elif isinstance(theta_object, IndexedVar) or theta_object.is_variable_type():
@@ -182,6 +187,15 @@ def convert_params_to_vars(model, param_names=None, fix_vars=False):
             model.del_component(obj)
             model.add_component(obj.name, pyo.Objective(rule=expr, sense=obj.sense))
 
+    # Convert Params to Vars in Suffixes
+    for s in model.component_objects(pyo.Suffix):
+        current_keys = list(s.keys())
+        for c in current_keys:
+            if c in comp_map:
+                s[comp_map[c]] = s.pop(c)
+
+        assert len(current_keys) == len(s.keys())
+
     # print('--- Updated Model ---')
     # model.pprint()
     # solver = pyo.SolverFactory('ipopt')
diff --git a/pyomo/contrib/parmest/utils/mpi_utils.py b/pyomo/contrib/parmest/utils/mpi_utils.py
index 35c4bf137bc..45e3260117d 100644
--- a/pyomo/contrib/parmest/utils/mpi_utils.py
+++ b/pyomo/contrib/parmest/utils/mpi_utils.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/parmest/utils/scenario_tree.py b/pyomo/contrib/parmest/utils/scenario_tree.py
index d46a8f2c5f0..f245e053cad 100644
--- a/pyomo/contrib/parmest/utils/scenario_tree.py
+++ b/pyomo/contrib/parmest/utils/scenario_tree.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # This software is distributed under the 3-clause BSD License.
 # Copied with minor modifications from mpisppy/scenario_tree.py
 # from the mpi-sppy library (https://github.com/Pyomo/mpi-sppy).
@@ -14,7 +25,7 @@
 
 def build_vardatalist(self, model, varlist=None):
     """
-    Convert a list of pyomo variables to a list of ScalarVar and _GeneralVarData. If varlist is none, builds a
+    Convert a list of pyomo variables to a list of ScalarVar and VarData. If varlist is none, builds a
     list of all variables in the model. The new list is stored in the vars_to_tighten attribute. By CD Laird
 
     Parameters
diff --git a/pyomo/contrib/piecewise/__init__.py b/pyomo/contrib/piecewise/__init__.py
index 33cfc6f1606..b23200b3f7d 100644
--- a/pyomo/contrib/piecewise/__init__.py
+++ b/pyomo/contrib/piecewise/__init__.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.contrib.piecewise.piecewise_linear_expression import (
     PiecewiseLinearExpression,
 )
@@ -22,3 +33,9 @@
 from pyomo.contrib.piecewise.transform.convex_combination import (
     ConvexCombinationTransformation,
 )
+from pyomo.contrib.piecewise.transform.nested_inner_repn import (
+    NestedInnerRepresentationGDPTransformation,
+)
+from pyomo.contrib.piecewise.transform.disaggregated_logarithmic import (
+    DisaggregatedLogarithmicMIPTransformation,
+)
diff --git a/pyomo/contrib/piecewise/piecewise_linear_expression.py b/pyomo/contrib/piecewise/piecewise_linear_expression.py
index ea1d95b0f51..ddcb7c6a42f 100644
--- a/pyomo/contrib/piecewise/piecewise_linear_expression.py
+++ b/pyomo/contrib/piecewise/piecewise_linear_expression.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/piecewise/piecewise_linear_function.py b/pyomo/contrib/piecewise/piecewise_linear_function.py
index 6d4fa658f88..e92edacc756 100644
--- a/pyomo/contrib/piecewise/piecewise_linear_function.py
+++ b/pyomo/contrib/piecewise/piecewise_linear_function.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -20,7 +20,7 @@
     PiecewiseLinearExpression,
 )
 from pyomo.core import Any, NonNegativeIntegers, value, Var
-from pyomo.core.base.block import _BlockData, Block
+from pyomo.core.base.block import BlockData, Block
 from pyomo.core.base.component import ModelComponentFactory
 from pyomo.core.base.expression import Expression
 from pyomo.core.base.global_set import UnindexedComponent_index
@@ -36,11 +36,11 @@
 logger = logging.getLogger(__name__)
 
 
-class PiecewiseLinearFunctionData(_BlockData):
+class PiecewiseLinearFunctionData(BlockData):
     _Block_reserved_words = Any
 
     def __init__(self, component=None):
-        _BlockData.__init__(self, component)
+        BlockData.__init__(self, component)
 
         with self._declare_reserved_components():
             self._expressions = Expression(NonNegativeIntegers)
diff --git a/pyomo/contrib/piecewise/tests/__init__.py b/pyomo/contrib/piecewise/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/piecewise/tests/__init__.py
+++ b/pyomo/contrib/piecewise/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/piecewise/tests/common_inner_repn_tests.py b/pyomo/contrib/piecewise/tests/common_inner_repn_tests.py
new file mode 100644
index 00000000000..e0b8e878be3
--- /dev/null
+++ b/pyomo/contrib/piecewise/tests/common_inner_repn_tests.py
@@ -0,0 +1,80 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+from pyomo.core import Var
+from pyomo.core.base import Constraint
+from pyomo.core.expr.compare import assertExpressionsEqual
+
+# This file contains check methods shared between GDP inner representation-based
+# transformations. Currently, those are the inner_representation_gdp and
+# nested_inner_repn_gdp transformations, since each have disjuncts with the
+# same structure.
+
+
+# Check one disjunct from the log model for proper contents
+def check_log_disjunct(test, d, pts, f, substitute_var, x):
+    test.assertEqual(len(d.component_map(Constraint)), 3)
+    # lambdas and indicator_var
+    test.assertEqual(len(d.component_map(Var)), 2)
+    test.assertIsInstance(d.lambdas, Var)
+    test.assertEqual(len(d.lambdas), 2)
+    for lamb in d.lambdas.values():
+        test.assertEqual(lamb.lb, 0)
+        test.assertEqual(lamb.ub, 1)
+    test.assertIsInstance(d.convex_combo, Constraint)
+    assertExpressionsEqual(test, d.convex_combo.expr, d.lambdas[0] + d.lambdas[1] == 1)
+    test.assertIsInstance(d.set_substitute, Constraint)
+    assertExpressionsEqual(
+        test, d.set_substitute.expr, substitute_var == f(x), places=7
+    )
+    test.assertIsInstance(d.linear_combo, Constraint)
+    test.assertEqual(len(d.linear_combo), 1)
+    assertExpressionsEqual(
+        test, d.linear_combo[0].expr, x == pts[0] * d.lambdas[0] + pts[1] * d.lambdas[1]
+    )
+
+
+# Check one disjunct from the paraboloid model for proper contents.
+def check_paraboloid_disjunct(test, d, pts, f, substitute_var, x1, x2):
+    test.assertEqual(len(d.component_map(Constraint)), 3)
+    # lambdas and indicator_var
+    test.assertEqual(len(d.component_map(Var)), 2)
+    test.assertIsInstance(d.lambdas, Var)
+    test.assertEqual(len(d.lambdas), 3)
+    for lamb in d.lambdas.values():
+        test.assertEqual(lamb.lb, 0)
+        test.assertEqual(lamb.ub, 1)
+    test.assertIsInstance(d.convex_combo, Constraint)
+    assertExpressionsEqual(
+        test, d.convex_combo.expr, d.lambdas[0] + d.lambdas[1] + d.lambdas[2] == 1
+    )
+    test.assertIsInstance(d.set_substitute, Constraint)
+    assertExpressionsEqual(
+        test, d.set_substitute.expr, substitute_var == f(x1, x2), places=7
+    )
+    test.assertIsInstance(d.linear_combo, Constraint)
+    test.assertEqual(len(d.linear_combo), 2)
+    assertExpressionsEqual(
+        test,
+        d.linear_combo[0].expr,
+        x1
+        == pts[0][0] * d.lambdas[0]
+        + pts[1][0] * d.lambdas[1]
+        + pts[2][0] * d.lambdas[2],
+    )
+    assertExpressionsEqual(
+        test,
+        d.linear_combo[1].expr,
+        x2
+        == pts[0][1] * d.lambdas[0]
+        + pts[1][1] * d.lambdas[1]
+        + pts[2][1] * d.lambdas[2],
+    )
diff --git a/pyomo/contrib/piecewise/tests/common_tests.py b/pyomo/contrib/piecewise/tests/common_tests.py
index c77d7064544..23e67474934 100644
--- a/pyomo/contrib/piecewise/tests/common_tests.py
+++ b/pyomo/contrib/piecewise/tests/common_tests.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/piecewise/tests/models.py b/pyomo/contrib/piecewise/tests/models.py
index be2811a70a4..1a8bef04ad7 100644
--- a/pyomo/contrib/piecewise/tests/models.py
+++ b/pyomo/contrib/piecewise/tests/models.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/piecewise/tests/test_disaggregated_logarithmic.py b/pyomo/contrib/piecewise/tests/test_disaggregated_logarithmic.py
new file mode 100644
index 00000000000..f848c610e9d
--- /dev/null
+++ b/pyomo/contrib/piecewise/tests/test_disaggregated_logarithmic.py
@@ -0,0 +1,275 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import pyomo.common.unittest as unittest
+from pyomo.contrib.piecewise.tests import models
+import pyomo.contrib.piecewise.tests.common_tests as ct
+from pyomo.core.base import TransformationFactory
+from pyomo.environ import SolverFactory, Var, Constraint
+from pyomo.core.expr.compare import assertExpressionsEqual
+
+
+class TestTransformPiecewiseModelToNestedInnerRepnMIP(unittest.TestCase):
+    def check_pw_log(self, m):
+        z = m.pw_log.get_transformation_var(m.log_expr)
+        self.assertIsInstance(z, Var)
+        # Now we can use those Vars to check on what the transformation created
+        log_block = z.parent_block()
+
+        # We should have three Vars, two of which are indexed, and five
+        # Constraints, three of which are indexed
+
+        self.assertEqual(len(log_block.component_map(Var)), 3)
+        self.assertEqual(len(log_block.component_map(Constraint)), 5)
+
+        # Constants
+        simplex_count = 3
+        log_simplex_count = 2
+        simplex_point_count = 2
+
+        # Substitute var
+        self.assertIsInstance(log_block.substitute_var, Var)
+        self.assertIs(m.obj.expr.expr, log_block.substitute_var)
+        # Binaries
+        self.assertIsInstance(log_block.binaries, Var)
+        self.assertEqual(len(log_block.binaries), log_simplex_count)
+        # Lambdas
+        self.assertIsInstance(log_block.lambdas, Var)
+        self.assertEqual(len(log_block.lambdas), simplex_count * simplex_point_count)
+        for l in log_block.lambdas.values():
+            self.assertEqual(l.lb, 0)
+            self.assertEqual(l.ub, 1)
+
+        # Convex combo constraint
+        self.assertIsInstance(log_block.convex_combo, Constraint)
+        assertExpressionsEqual(
+            self,
+            log_block.convex_combo.expr,
+            log_block.lambdas[0, 0]
+            + log_block.lambdas[0, 1]
+            + log_block.lambdas[1, 0]
+            + log_block.lambdas[1, 1]
+            + log_block.lambdas[2, 0]
+            + log_block.lambdas[2, 1]
+            == 1,
+        )
+
+        # Set substitute constraint
+        self.assertIsInstance(log_block.set_substitute, Constraint)
+        assertExpressionsEqual(
+            self,
+            log_block.set_substitute.expr,
+            log_block.substitute_var
+            == log_block.lambdas[0, 0] * m.f1(1)
+            + log_block.lambdas[1, 0] * m.f2(3)
+            + log_block.lambdas[2, 0] * m.f3(6)
+            + log_block.lambdas[0, 1] * m.f1(3)
+            + log_block.lambdas[1, 1] * m.f2(6)
+            + log_block.lambdas[2, 1] * m.f3(10),
+            places=7,
+        )
+
+        # x constraint
+        self.assertIsInstance(log_block.x_constraint, Constraint)
+        # one-dimensional case, so there is only one x variable here
+        self.assertEqual(len(log_block.x_constraint), 1)
+        assertExpressionsEqual(
+            self,
+            log_block.x_constraint[0].expr,
+            m.x
+            == 1 * log_block.lambdas[0, 0]
+            + 3 * log_block.lambdas[0, 1]
+            + 3 * log_block.lambdas[1, 0]
+            + 6 * log_block.lambdas[1, 1]
+            + 6 * log_block.lambdas[2, 0]
+            + 10 * log_block.lambdas[2, 1],
+        )
+
+        # simplex choice 1 constraint enables lambdas when binaries are on
+        self.assertEqual(len(log_block.simplex_choice_1), log_simplex_count)
+        assertExpressionsEqual(
+            self,
+            log_block.simplex_choice_1[0].expr,
+            log_block.lambdas[2, 0] + log_block.lambdas[2, 1] <= log_block.binaries[0],
+        )
+        assertExpressionsEqual(
+            self,
+            log_block.simplex_choice_1[1].expr,
+            log_block.lambdas[1, 0] + log_block.lambdas[1, 1] <= log_block.binaries[1],
+        )
+        # simplex choice 2 constraint enables lambdas when binaries are off
+        self.assertEqual(len(log_block.simplex_choice_2), log_simplex_count)
+        assertExpressionsEqual(
+            self,
+            log_block.simplex_choice_2[0].expr,
+            log_block.lambdas[0, 0]
+            + log_block.lambdas[0, 1]
+            + log_block.lambdas[1, 0]
+            + log_block.lambdas[1, 1]
+            <= 1 - log_block.binaries[0],
+        )
+        assertExpressionsEqual(
+            self,
+            log_block.simplex_choice_2[1].expr,
+            log_block.lambdas[0, 0]
+            + log_block.lambdas[0, 1]
+            + log_block.lambdas[2, 0]
+            + log_block.lambdas[2, 1]
+            <= 1 - log_block.binaries[1],
+        )
+
+    def check_pw_paraboloid(self, m):
+        # This is a little larger, but at least test that the right numbers of
+        # everything are created
+        z = m.pw_paraboloid.get_transformation_var(m.paraboloid_expr)
+        self.assertIsInstance(z, Var)
+        paraboloid_block = z.parent_block()
+
+        self.assertEqual(len(paraboloid_block.component_map(Var)), 3)
+        self.assertEqual(len(paraboloid_block.component_map(Constraint)), 5)
+
+        # Constants
+        simplex_count = 4
+        log_simplex_count = 2
+        simplex_point_count = 3
+
+        # Substitute var
+        self.assertIsInstance(paraboloid_block.substitute_var, Var)
+        # Binaries
+        self.assertIsInstance(paraboloid_block.binaries, Var)
+        self.assertEqual(len(paraboloid_block.binaries), log_simplex_count)
+        # Lambdas
+        self.assertIsInstance(paraboloid_block.lambdas, Var)
+        self.assertEqual(
+            len(paraboloid_block.lambdas), simplex_count * simplex_point_count
+        )
+        for l in paraboloid_block.lambdas.values():
+            self.assertEqual(l.lb, 0)
+            self.assertEqual(l.ub, 1)
+
+        # Convex combo constraint
+        self.assertIsInstance(paraboloid_block.convex_combo, Constraint)
+        assertExpressionsEqual(
+            self,
+            paraboloid_block.convex_combo.expr,
+            paraboloid_block.lambdas[0, 0]
+            + paraboloid_block.lambdas[0, 1]
+            + paraboloid_block.lambdas[0, 2]
+            + paraboloid_block.lambdas[1, 0]
+            + paraboloid_block.lambdas[1, 1]
+            + paraboloid_block.lambdas[1, 2]
+            + paraboloid_block.lambdas[2, 0]
+            + paraboloid_block.lambdas[2, 1]
+            + paraboloid_block.lambdas[2, 2]
+            + paraboloid_block.lambdas[3, 0]
+            + paraboloid_block.lambdas[3, 1]
+            + paraboloid_block.lambdas[3, 2]
+            == 1,
+        )
+
+        # Set substitute constraint
+        self.assertIsInstance(paraboloid_block.set_substitute, Constraint)
+        assertExpressionsEqual(
+            self,
+            paraboloid_block.set_substitute.expr,
+            paraboloid_block.substitute_var
+            == paraboloid_block.lambdas[0, 0] * m.g1(0, 1)
+            + paraboloid_block.lambdas[1, 0] * m.g1(0, 1)
+            + paraboloid_block.lambdas[2, 0] * m.g2(3, 4)
+            + paraboloid_block.lambdas[3, 0] * m.g2(0, 7)
+            + paraboloid_block.lambdas[0, 1] * m.g1(0, 4)
+            + paraboloid_block.lambdas[1, 1] * m.g1(3, 4)
+            + paraboloid_block.lambdas[2, 1] * m.g2(3, 7)
+            + paraboloid_block.lambdas[3, 1] * m.g2(0, 4)
+            + paraboloid_block.lambdas[0, 2] * m.g1(3, 4)
+            + paraboloid_block.lambdas[1, 2] * m.g1(3, 1)
+            + paraboloid_block.lambdas[2, 2] * m.g2(0, 7)
+            + paraboloid_block.lambdas[3, 2] * m.g2(3, 4),
+            places=7,
+        )
+
+        # x constraint
+        self.assertIsInstance(paraboloid_block.x_constraint, Constraint)
+        # Here we have two x variables
+        self.assertEqual(len(paraboloid_block.x_constraint), 2)
+        assertExpressionsEqual(
+            self,
+            paraboloid_block.x_constraint[0].expr,
+            m.x1
+            == 0 * paraboloid_block.lambdas[0, 0]
+            + 0 * paraboloid_block.lambdas[0, 1]
+            + 3 * paraboloid_block.lambdas[0, 2]
+            + 0 * paraboloid_block.lambdas[1, 0]
+            + 3 * paraboloid_block.lambdas[1, 1]
+            + 3 * paraboloid_block.lambdas[1, 2]
+            + 3 * paraboloid_block.lambdas[2, 0]
+            + 3 * paraboloid_block.lambdas[2, 1]
+            + 0 * paraboloid_block.lambdas[2, 2]
+            + 0 * paraboloid_block.lambdas[3, 0]
+            + 0 * paraboloid_block.lambdas[3, 1]
+            + 3 * paraboloid_block.lambdas[3, 2],
+        )
+        assertExpressionsEqual(
+            self,
+            paraboloid_block.x_constraint[1].expr,
+            m.x2
+            == 1 * paraboloid_block.lambdas[0, 0]
+            + 4 * paraboloid_block.lambdas[0, 1]
+            + 4 * paraboloid_block.lambdas[0, 2]
+            + 1 * paraboloid_block.lambdas[1, 0]
+            + 4 * paraboloid_block.lambdas[1, 1]
+            + 1 * paraboloid_block.lambdas[1, 2]
+            + 4 * paraboloid_block.lambdas[2, 0]
+            + 7 * paraboloid_block.lambdas[2, 1]
+            + 7 * paraboloid_block.lambdas[2, 2]
+            + 7 * paraboloid_block.lambdas[3, 0]
+            + 4 * paraboloid_block.lambdas[3, 1]
+            + 4 * paraboloid_block.lambdas[3, 2],
+        )
+
+        # The choices will get long, so let's just assert we have enough
+        self.assertEqual(len(paraboloid_block.simplex_choice_1), log_simplex_count)
+        self.assertEqual(len(paraboloid_block.simplex_choice_2), log_simplex_count)
+
+    # Test methods using the common_tests.py code.
+    def test_transformation_do_not_descend(self):
+        ct.check_transformation_do_not_descend(
+            self, 'contrib.piecewise.disaggregated_logarithmic'
+        )
+
+    def test_transformation_PiecewiseLinearFunction_targets(self):
+        ct.check_transformation_PiecewiseLinearFunction_targets(
+            self, 'contrib.piecewise.disaggregated_logarithmic'
+        )
+
+    def test_descend_into_expressions(self):
+        ct.check_descend_into_expressions(
+            self, 'contrib.piecewise.disaggregated_logarithmic'
+        )
+
+    def test_descend_into_expressions_constraint_target(self):
+        ct.check_descend_into_expressions_constraint_target(
+            self, 'contrib.piecewise.disaggregated_logarithmic'
+        )
+
+    def test_descend_into_expressions_objective_target(self):
+        ct.check_descend_into_expressions_objective_target(
+            self, 'contrib.piecewise.disaggregated_logarithmic'
+        )
+
+    # Check solution of the log(x) model
+    @unittest.skipUnless(SolverFactory('gurobi').available(), 'Gurobi is not available')
+    @unittest.skipUnless(SolverFactory('gurobi').license_is_valid(), 'No license')
+    def test_solve_log_model(self):
+        m = models.make_log_x_model()
+        TransformationFactory("contrib.piecewise.disaggregated_logarithmic").apply_to(m)
+        SolverFactory("gurobi").solve(m)
+        ct.check_log_x_model_soln(self, m)
diff --git a/pyomo/contrib/piecewise/tests/test_inner_repn_gdp.py b/pyomo/contrib/piecewise/tests/test_inner_repn_gdp.py
index a0dbd1cca19..e7505bb92d3 100644
--- a/pyomo/contrib/piecewise/tests/test_inner_repn_gdp.py
+++ b/pyomo/contrib/piecewise/tests/test_inner_repn_gdp.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -12,6 +12,7 @@
 import pyomo.common.unittest as unittest
 from pyomo.contrib.piecewise.tests import models
 import pyomo.contrib.piecewise.tests.common_tests as ct
+import pyomo.contrib.piecewise.tests.common_inner_repn_tests as inner_repn_tests
 from pyomo.core.base import TransformationFactory
 from pyomo.core.expr.compare import (
     assertExpressionsEqual,
@@ -22,67 +23,6 @@
 
 
 class TestTransformPiecewiseModelToInnerRepnGDP(unittest.TestCase):
-    def check_log_disjunct(self, d, pts, f, substitute_var, x):
-        self.assertEqual(len(d.component_map(Constraint)), 3)
-        # lambdas and indicator_var
-        self.assertEqual(len(d.component_map(Var)), 2)
-        self.assertIsInstance(d.lambdas, Var)
-        self.assertEqual(len(d.lambdas), 2)
-        for lamb in d.lambdas.values():
-            self.assertEqual(lamb.lb, 0)
-            self.assertEqual(lamb.ub, 1)
-        self.assertIsInstance(d.convex_combo, Constraint)
-        assertExpressionsEqual(
-            self, d.convex_combo.expr, d.lambdas[0] + d.lambdas[1] == 1
-        )
-        self.assertIsInstance(d.set_substitute, Constraint)
-        assertExpressionsEqual(
-            self, d.set_substitute.expr, substitute_var == f(x), places=7
-        )
-        self.assertIsInstance(d.linear_combo, Constraint)
-        self.assertEqual(len(d.linear_combo), 1)
-        assertExpressionsEqual(
-            self,
-            d.linear_combo[0].expr,
-            x == pts[0] * d.lambdas[0] + pts[1] * d.lambdas[1],
-        )
-
-    def check_paraboloid_disjunct(self, d, pts, f, substitute_var, x1, x2):
-        self.assertEqual(len(d.component_map(Constraint)), 3)
-        # lambdas and indicator_var
-        self.assertEqual(len(d.component_map(Var)), 2)
-        self.assertIsInstance(d.lambdas, Var)
-        self.assertEqual(len(d.lambdas), 3)
-        for lamb in d.lambdas.values():
-            self.assertEqual(lamb.lb, 0)
-            self.assertEqual(lamb.ub, 1)
-        self.assertIsInstance(d.convex_combo, Constraint)
-        assertExpressionsEqual(
-            self, d.convex_combo.expr, d.lambdas[0] + d.lambdas[1] + d.lambdas[2] == 1
-        )
-        self.assertIsInstance(d.set_substitute, Constraint)
-        assertExpressionsEqual(
-            self, d.set_substitute.expr, substitute_var == f(x1, x2), places=7
-        )
-        self.assertIsInstance(d.linear_combo, Constraint)
-        self.assertEqual(len(d.linear_combo), 2)
-        assertExpressionsEqual(
-            self,
-            d.linear_combo[0].expr,
-            x1
-            == pts[0][0] * d.lambdas[0]
-            + pts[1][0] * d.lambdas[1]
-            + pts[2][0] * d.lambdas[2],
-        )
-        assertExpressionsEqual(
-            self,
-            d.linear_combo[1].expr,
-            x2
-            == pts[0][1] * d.lambdas[0]
-            + pts[1][1] * d.lambdas[1]
-            + pts[2][1] * d.lambdas[2],
-        )
-
     def check_pw_log(self, m):
         ##
         # Check the transformation of the approximation of log(x)
@@ -101,7 +41,9 @@ def check_pw_log(self, m):
             log_block.disjuncts[2]: ((6, 10), m.f3),
         }
         for d, (pts, f) in disjuncts_dict.items():
-            self.check_log_disjunct(d, pts, f, log_block.substitute_var, m.x)
+            inner_repn_tests.check_log_disjunct(
+                self, d, pts, f, log_block.substitute_var, m.x
+            )
 
         # Check the Disjunction
         self.assertIsInstance(log_block.pick_a_piece, Disjunction)
@@ -129,8 +71,8 @@ def check_pw_paraboloid(self, m):
             paraboloid_block.disjuncts[3]: ([(0, 7), (0, 4), (3, 4)], m.g2),
         }
         for d, (pts, f) in disjuncts_dict.items():
-            self.check_paraboloid_disjunct(
-                d, pts, f, paraboloid_block.substitute_var, m.x1, m.x2
+            inner_repn_tests.check_paraboloid_disjunct(
+                self, d, pts, f, paraboloid_block.substitute_var, m.x1, m.x2
             )
 
         # Check the Disjunction
diff --git a/pyomo/contrib/piecewise/tests/test_nested_inner_repn_gdp.py b/pyomo/contrib/piecewise/tests/test_nested_inner_repn_gdp.py
new file mode 100644
index 00000000000..2024f014f55
--- /dev/null
+++ b/pyomo/contrib/piecewise/tests/test_nested_inner_repn_gdp.py
@@ -0,0 +1,135 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import pyomo.common.unittest as unittest
+from pyomo.contrib.piecewise.tests import models
+import pyomo.contrib.piecewise.tests.common_tests as ct
+import pyomo.contrib.piecewise.tests.common_inner_repn_tests as inner_repn_tests
+from pyomo.core.base import TransformationFactory
+from pyomo.environ import SolverFactory, Var, Constraint
+from pyomo.gdp import Disjunction, Disjunct
+from pyomo.core.expr.compare import assertExpressionsEqual
+
+
+# Test the nested inner repn gdp model using the common_tests code
+class TestTransformPiecewiseModelToNestedInnerRepnGDP(unittest.TestCase):
+    # Check the structure of the log PWLF Block
+    def check_pw_log(self, m):
+        z = m.pw_log.get_transformation_var(m.log_expr)
+        self.assertIsInstance(z, Var)
+        # Now we can use those Vars to check on what the transformation created
+        log_block = z.parent_block()
+
+        # Not using ct.check_trans_block_structure() because these are slightly
+        # different
+        # Two top-level disjuncts
+        self.assertEqual(len(log_block.component_map(Disjunct)), 2)
+        # One disjunction
+        self.assertEqual(len(log_block.component_map(Disjunction)), 1)
+        # The 'z' var (that we will substitute in for the function being
+        # approximated) is here:
+        self.assertEqual(len(log_block.component_map(Var)), 1)
+        self.assertIsInstance(log_block.substitute_var, Var)
+
+        # Check the tree structure, which should be heavier on the right
+        # Parent disjunction
+        self.assertIsInstance(log_block.disj, Disjunction)
+        self.assertEqual(len(log_block.disj.disjuncts), 2)
+
+        # Left disjunct with constraints
+        self.assertIsInstance(log_block.d_l, Disjunct)
+        inner_repn_tests.check_log_disjunct(
+            self, log_block.d_l, (1, 3), m.f1, log_block.substitute_var, m.x
+        )
+
+        # Right disjunct with disjunction
+        self.assertIsInstance(log_block.d_r, Disjunct)
+        self.assertIsInstance(log_block.d_r.inner_disjunction_r, Disjunction)
+        self.assertEqual(len(log_block.d_r.inner_disjunction_r.disjuncts), 2)
+
+        # Left and right child disjuncts with constraints
+        self.assertIsInstance(log_block.d_r.d_l, Disjunct)
+        inner_repn_tests.check_log_disjunct(
+            self, log_block.d_r.d_l, (3, 6), m.f2, log_block.substitute_var, m.x
+        )
+        self.assertIsInstance(log_block.d_r.d_r, Disjunct)
+        inner_repn_tests.check_log_disjunct(
+            self, log_block.d_r.d_r, (6, 10), m.f3, log_block.substitute_var, m.x
+        )
+
+        # Check that this also became the objective
+        self.assertIs(m.obj.expr.expr, log_block.substitute_var)
+
+    # Check the structure of the paraboloid PWLF block
+    def check_pw_paraboloid(self, m):
+        z = m.pw_paraboloid.get_transformation_var(m.paraboloid_expr)
+        self.assertIsInstance(z, Var)
+        paraboloid_block = z.parent_block()
+
+        # Two top-level disjuncts
+        self.assertEqual(len(paraboloid_block.component_map(Disjunct)), 2)
+        # One disjunction
+        self.assertEqual(len(paraboloid_block.component_map(Disjunction)), 1)
+        # The 'z' var (that we will substitute in for the function being
+        # approximated) is here:
+        self.assertEqual(len(paraboloid_block.component_map(Var)), 1)
+        self.assertIsInstance(paraboloid_block.substitute_var, Var)
+
+        # This one should have an even tree with four leaf disjuncts
+        disjuncts_dict = {
+            paraboloid_block.d_l.d_l: ([(0, 1), (0, 4), (3, 4)], m.g1),
+            paraboloid_block.d_l.d_r: ([(0, 1), (3, 4), (3, 1)], m.g1),
+            paraboloid_block.d_r.d_l: ([(3, 4), (3, 7), (0, 7)], m.g2),
+            paraboloid_block.d_r.d_r: ([(0, 7), (0, 4), (3, 4)], m.g2),
+        }
+        for d, (pts, f) in disjuncts_dict.items():
+            inner_repn_tests.check_paraboloid_disjunct(
+                self, d, pts, f, paraboloid_block.substitute_var, m.x1, m.x2
+            )
+
+        # And check the substitute Var is in the objective now.
+        self.assertIs(m.indexed_c[0].body.args[0].expr, paraboloid_block.substitute_var)
+
+    # Test methods using the common_tests.py code. Copied in from test_inner_repn_gdp.py.
+    def test_transformation_do_not_descend(self):
+        ct.check_transformation_do_not_descend(
+            self, 'contrib.piecewise.nested_inner_repn_gdp'
+        )
+
+    def test_transformation_PiecewiseLinearFunction_targets(self):
+        ct.check_transformation_PiecewiseLinearFunction_targets(
+            self, 'contrib.piecewise.nested_inner_repn_gdp'
+        )
+
+    def test_descend_into_expressions(self):
+        ct.check_descend_into_expressions(
+            self, 'contrib.piecewise.nested_inner_repn_gdp'
+        )
+
+    def test_descend_into_expressions_constraint_target(self):
+        ct.check_descend_into_expressions_constraint_target(
+            self, 'contrib.piecewise.nested_inner_repn_gdp'
+        )
+
+    def test_descend_into_expressions_objective_target(self):
+        ct.check_descend_into_expressions_objective_target(
+            self, 'contrib.piecewise.nested_inner_repn_gdp'
+        )
+
+    # Check the solution of the log(x) model
+    @unittest.skipUnless(SolverFactory('gurobi').available(), 'Gurobi is not available')
+    @unittest.skipUnless(SolverFactory('gurobi').license_is_valid(), 'No license')
+    def test_solve_log_model(self):
+        m = models.make_log_x_model()
+        TransformationFactory("contrib.piecewise.nested_inner_repn_gdp").apply_to(m)
+        TransformationFactory("gdp.bigm").apply_to(m)
+        SolverFactory("gurobi").solve(m)
+        ct.check_log_x_model_soln(self, m)
diff --git a/pyomo/contrib/piecewise/tests/test_outer_repn_gdp.py b/pyomo/contrib/piecewise/tests/test_outer_repn_gdp.py
index edc5d9d3d95..5ee18875cb9 100644
--- a/pyomo/contrib/piecewise/tests/test_outer_repn_gdp.py
+++ b/pyomo/contrib/piecewise/tests/test_outer_repn_gdp.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/piecewise/tests/test_piecewise_linear_function.py b/pyomo/contrib/piecewise/tests/test_piecewise_linear_function.py
index e740e5e3384..571601fefbc 100644
--- a/pyomo/contrib/piecewise/tests/test_piecewise_linear_function.py
+++ b/pyomo/contrib/piecewise/tests/test_piecewise_linear_function.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/piecewise/tests/test_reduced_inner_repn.py b/pyomo/contrib/piecewise/tests/test_reduced_inner_repn.py
index a2d41c04016..b70281c83ed 100644
--- a/pyomo/contrib/piecewise/tests/test_reduced_inner_repn.py
+++ b/pyomo/contrib/piecewise/tests/test_reduced_inner_repn.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/piecewise/transform/__init__.py b/pyomo/contrib/piecewise/transform/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/piecewise/transform/__init__.py
+++ b/pyomo/contrib/piecewise/transform/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/piecewise/transform/convex_combination.py b/pyomo/contrib/piecewise/transform/convex_combination.py
index abfeac27129..21b72bd9e5d 100644
--- a/pyomo/contrib/piecewise/transform/convex_combination.py
+++ b/pyomo/contrib/piecewise/transform/convex_combination.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/piecewise/transform/disaggregated_convex_combination.py b/pyomo/contrib/piecewise/transform/disaggregated_convex_combination.py
index 44059935e09..0117bf1d045 100644
--- a/pyomo/contrib/piecewise/transform/disaggregated_convex_combination.py
+++ b/pyomo/contrib/piecewise/transform/disaggregated_convex_combination.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/piecewise/transform/disaggregated_logarithmic.py b/pyomo/contrib/piecewise/transform/disaggregated_logarithmic.py
new file mode 100644
index 00000000000..d582cdcfff5
--- /dev/null
+++ b/pyomo/contrib/piecewise/transform/disaggregated_logarithmic.py
@@ -0,0 +1,202 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+from pyomo.contrib.piecewise.transform.piecewise_linear_transformation_base import (
+    PiecewiseLinearTransformationBase,
+)
+from pyomo.core import Constraint, Binary, Var, RangeSet, Set
+from pyomo.core.base import TransformationFactory
+from pyomo.common.errors import DeveloperError
+from math import ceil, log2
+
+
+@TransformationFactory.register(
+    "contrib.piecewise.disaggregated_logarithmic",
+    doc="""
+    Represent a piecewise linear function "logarithmically" by using a MIP with
+    log_2(|P|) binary decision variables. This is a direct-to-MIP transformation;
+    GDP is not used.
+    """,
+)
+class DisaggregatedLogarithmicMIPTransformation(PiecewiseLinearTransformationBase):
+    """
+    Represent a piecewise linear function "logarithmically" by using a MIP with
+    log_2(|P|) binary decision variables, following the "disaggregated logarithmic"
+    method from [1]. This is a direct-to-MIP transformation; GDP is not used.
+    This method of logarithmically formulating the piecewise linear function
+    imposes no restrictions on the family of polytopes, but we assume we have
+    simplices in this code.
+
+    References
+    ----------
+    [1] J.P. Vielma, S. Ahmed, and G. Nemhauser, "Mixed-integer models
+        for nonseparable piecewise-linear optimization: unifying framework
+        and extensions," Operations Research, vol. 58, no. 2, pp. 305-315,
+        2010.
+    """
+
+    CONFIG = PiecewiseLinearTransformationBase.CONFIG()
+    _transformation_name = "pw_linear_disaggregated_log"
+
+    # Implement to use PiecewiseLinearTransformationBase. This function returns the Var
+    # that replaces the transformed piecewise linear expr
+    def _transform_pw_linear_expr(self, pw_expr, pw_linear_func, transformation_block):
+        # Get a new Block for our transformation in transformation_block.transformed_functions,
+        # which is a Block(Any). This is where we will put our new components.
+        transBlock = transformation_block.transformed_functions[
+            len(transformation_block.transformed_functions)
+        ]
+
+        # Dimensionality of the PWLF
+        dimension = pw_expr.nargs()
+        transBlock.dimension_indices = RangeSet(0, dimension - 1)
+
+        # Substitute Var that will hold the value of the PWLE
+        substitute_var = transBlock.substitute_var = Var()
+        pw_linear_func.map_transformation_var(pw_expr, substitute_var)
+
+        # Bounds for the substitute_var that we will widen
+        substitute_var_lb = float("inf")
+        substitute_var_ub = -float("inf")
+
+        # Simplices are tuples of indices of points. Give them their own indices, too
+        simplices = pw_linear_func._simplices
+        num_simplices = len(simplices)
+        transBlock.simplex_indices = RangeSet(0, num_simplices - 1)
+        # Assumption: the simplices are really full-dimensional simplices and all have the
+        # same number of points, which is dimension + 1
+        transBlock.simplex_point_indices = RangeSet(0, dimension)
+
+        # Enumeration of simplices: map from simplex number to simplex object
+        idx_to_simplex = {k: v for k, v in zip(transBlock.simplex_indices, simplices)}
+
+        # List of tuples of simplex indices with their linear function
+        simplex_indices_and_lin_funcs = list(
+            zip(transBlock.simplex_indices, pw_linear_func._linear_functions)
+        )
+
+        # We don't seem to get a convenient opportunity later, so let's just widen
+        # the bounds here. All we need to do is go through the corners of each simplex.
+        for P, linear_func in simplex_indices_and_lin_funcs:
+            for v in transBlock.simplex_point_indices:
+                val = linear_func(*pw_linear_func._points[idx_to_simplex[P][v]])
+                if val < substitute_var_lb:
+                    substitute_var_lb = val
+                if val > substitute_var_ub:
+                    substitute_var_ub = val
+        transBlock.substitute_var.setlb(substitute_var_lb)
+        transBlock.substitute_var.setub(substitute_var_ub)
+
+        log_dimension = ceil(log2(num_simplices))
+        transBlock.log_simplex_indices = RangeSet(0, log_dimension - 1)
+        transBlock.binaries = Var(transBlock.log_simplex_indices, domain=Binary)
+
+        # Injective function B: \mathcal{P} -> {0,1}^ceil(log_2(|P|)) used to identify simplices
+        # (really just polytopes are required) with binary vectors. Any injective function
+        # is enough here.
+        B = {}
+        for i in transBlock.simplex_indices:
+            # map index(P) -> corresponding vector in {0, 1}^n
+            B[i] = self._get_binary_vector(i, log_dimension)
+
+        # Build up P_0 and P_plus ahead of time.
+
+        # {P \in \mathcal{P} | B(P)_l = 0}
+        def P_0_init(m, l):
+            return [p for p in transBlock.simplex_indices if B[p][l] == 0]
+
+        transBlock.P_0 = Set(transBlock.log_simplex_indices, initialize=P_0_init)
+
+        # {P \in \mathcal{P} | B(P)_l = 1}
+        def P_plus_init(m, l):
+            return [p for p in transBlock.simplex_indices if B[p][l] == 1]
+
+        transBlock.P_plus = Set(transBlock.log_simplex_indices, initialize=P_plus_init)
+
+        # The lambda variables \lambda_{P,v} are indexed by the simplex and the point in it
+        transBlock.lambdas = Var(
+            transBlock.simplex_indices, transBlock.simplex_point_indices, bounds=(0, 1)
+        )
+
+        # Numbered citations are from Vielma et al 2010, Mixed-Integer Models
+        # for Nonseparable Piecewise-Linear Optimization
+
+        # Sum of all lambdas is one (6b)
+        transBlock.convex_combo = Constraint(
+            expr=sum(
+                transBlock.lambdas[P, v]
+                for P in transBlock.simplex_indices
+                for v in transBlock.simplex_point_indices
+            )
+            == 1
+        )
+
+        # The branching rules, establishing using the binaries that only one simplex's lambda
+        # coefficients may be nonzero
+        # Enabling lambdas when binaries are on
+        @transBlock.Constraint(transBlock.log_simplex_indices)  # (6c.1)
+        def simplex_choice_1(b, l):
+            return (
+                sum(
+                    transBlock.lambdas[P, v]
+                    for P in transBlock.P_plus[l]
+                    for v in transBlock.simplex_point_indices
+                )
+                <= transBlock.binaries[l]
+            )
+
+        # Disabling lambdas when binaries are on
+        @transBlock.Constraint(transBlock.log_simplex_indices)  # (6c.2)
+        def simplex_choice_2(b, l):
+            return (
+                sum(
+                    transBlock.lambdas[P, v]
+                    for P in transBlock.P_0[l]
+                    for v in transBlock.simplex_point_indices
+                )
+                <= 1 - transBlock.binaries[l]
+            )
+
+        # for i, (simplex, pwlf) in enumerate(choices):
+        # x_i = sum(lambda_P,v v_i, P in polytopes, v in V(P))
+        @transBlock.Constraint(transBlock.dimension_indices)  # (6a.1)
+        def x_constraint(b, i):
+            return pw_expr.args[i] == sum(
+                transBlock.lambdas[P, v]
+                * pw_linear_func._points[idx_to_simplex[P][v]][i]
+                for P in transBlock.simplex_indices
+                for v in transBlock.simplex_point_indices
+            )
+
+        # Make the substitute Var equal the PWLE (6a.2)
+        transBlock.set_substitute = Constraint(
+            expr=substitute_var
+            == sum(
+                transBlock.lambdas[P, v]
+                * linear_func(*pw_linear_func._points[idx_to_simplex[P][v]])
+                for v in transBlock.simplex_point_indices
+                for (P, linear_func) in simplex_indices_and_lin_funcs
+            )
+        )
+
+        return substitute_var
+
+    # Not a Gray code, just a regular binary representation
+    # TODO test the Gray codes too
+    # note: Must have num != 0 and ceil(log2(num)) > length to be valid
+    def _get_binary_vector(self, num, length):
+        ans = []
+        for i in range(length):
+            ans.append(num & 1)
+            num >>= 1
+        assert not num
+        ans.reverse()
+        return tuple(ans)
diff --git a/pyomo/contrib/piecewise/transform/inner_representation_gdp.py b/pyomo/contrib/piecewise/transform/inner_representation_gdp.py
index 627e41aeae9..e4818c1cbb9 100644
--- a/pyomo/contrib/piecewise/transform/inner_representation_gdp.py
+++ b/pyomo/contrib/piecewise/transform/inner_representation_gdp.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -10,8 +10,8 @@
 #  ___________________________________________________________________________
 
 from pyomo.contrib.fbbt.fbbt import compute_bounds_on_expr
-from pyomo.contrib.piecewise.transform.piecewise_to_gdp_transformation import (
-    PiecewiseLinearToGDP,
+from pyomo.contrib.piecewise.transform.piecewise_linear_transformation_base import (
+    PiecewiseLinearTransformationBase,
 )
 from pyomo.core import Constraint, NonNegativeIntegers, Suffix, Var
 from pyomo.core.base import TransformationFactory
@@ -25,7 +25,7 @@
     "simplices that are the domains of the linear "
     "functions.",
 )
-class InnerRepresentationGDPTransformation(PiecewiseLinearToGDP):
+class InnerRepresentationGDPTransformation(PiecewiseLinearTransformationBase):
     """
     Convert a model involving piecewise linear expressions into a GDP by
     representing the piecewise linear functions as Disjunctions where the
@@ -49,7 +49,7 @@ class InnerRepresentationGDPTransformation(PiecewiseLinearToGDP):
            this mode, targets must be Blocks, Constraints, and/or Objectives.
     """
 
-    CONFIG = PiecewiseLinearToGDP.CONFIG()
+    CONFIG = PiecewiseLinearTransformationBase.CONFIG()
     _transformation_name = 'pw_linear_inner_repn'
 
     def _transform_pw_linear_expr(self, pw_expr, pw_linear_func, transformation_block):
diff --git a/pyomo/contrib/piecewise/transform/multiple_choice.py b/pyomo/contrib/piecewise/transform/multiple_choice.py
index 97dc8e9d2b3..9291afa8862 100644
--- a/pyomo/contrib/piecewise/transform/multiple_choice.py
+++ b/pyomo/contrib/piecewise/transform/multiple_choice.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/piecewise/transform/nested_inner_repn.py b/pyomo/contrib/piecewise/transform/nested_inner_repn.py
new file mode 100644
index 00000000000..dbbd8c73bad
--- /dev/null
+++ b/pyomo/contrib/piecewise/transform/nested_inner_repn.py
@@ -0,0 +1,209 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+from pyomo.contrib.fbbt.fbbt import compute_bounds_on_expr
+from pyomo.contrib.piecewise.transform.piecewise_linear_transformation_base import (
+    PiecewiseLinearTransformationBase,
+)
+from pyomo.core import Constraint, NonNegativeIntegers, Suffix, Var
+from pyomo.core.base import TransformationFactory
+from pyomo.gdp import Disjunction
+from pyomo.common.errors import DeveloperError
+
+
+@TransformationFactory.register(
+    "contrib.piecewise.nested_inner_repn_gdp",
+    doc="""
+    Represent a piecewise linear function by using a nested GDP to determine
+    which polytope a point is in, then representing it as a convex combination
+    of extreme points, with multipliers "local" to that particular polytope,
+    i.e., not shared with neighbors. This formulation has linearly many Boolean
+    variables, though up to variable substitution, it has logarithmically many.
+    """,
+)
+class NestedInnerRepresentationGDPTransformation(PiecewiseLinearTransformationBase):
+    """
+    Represent a piecewise linear function by using a nested GDP to determine
+    which polytope a point is in, then representing it as a convex combination
+    of extreme points, with multipliers "local" to that particular polytope,
+    i.e., not shared with neighbors. This method of formulating the piecewise
+    linear function imposes no restrictions on the family of polytopes. Note
+    that this is NOT a logarithmic formulation - it has linearly many Boolean
+    variables.  However, it is inspired by the disaggregated logarithmic
+    formulation of [1]. Up to variable substitution, the amount of Boolean
+    variables is logarithmic, as in [1].
+
+    References
+    ----------
+    [1] J.P. Vielma, S. Ahmed, and G. Nemhauser, "Mixed-integer models
+        for nonseparable piecewise-linear optimization: unifying framework
+        and extensions," Operations Research, vol. 58, no. 2, pp. 305-315,
+        2010.
+    """
+
+    CONFIG = PiecewiseLinearTransformationBase.CONFIG()
+    _transformation_name = "pw_linear_nested_inner_repn"
+
+    # Implement to use PiecewiseLinearTransformationBase. This function returns the Var
+    # that replaces the transformed piecewise linear expr
+    def _transform_pw_linear_expr(self, pw_expr, pw_linear_func, transformation_block):
+        # Get a new Block() in transformation_block.transformed_functions, which
+        # is a Block(Any)
+        transBlock = transformation_block.transformed_functions[
+            len(transformation_block.transformed_functions)
+        ]
+
+        substitute_var = transBlock.substitute_var = Var()
+        pw_linear_func.map_transformation_var(pw_expr, substitute_var)
+        transBlock.substitute_var_lb = float("inf")
+        transBlock.substitute_var_ub = -float("inf")
+
+        choices = list(zip(pw_linear_func._simplices, pw_linear_func._linear_functions))
+
+        # If there was only one choice, don't bother making a disjunction, just
+        # use the linear function directly (but still use the substitute_var for
+        # consistency).
+        if len(choices) == 1:
+            (_, linear_func) = choices[0]  # simplex isn't important in this case
+            linear_func_expr = linear_func(*pw_expr.args)
+            transBlock.set_substitute = Constraint(
+                expr=substitute_var == linear_func_expr
+            )
+            (transBlock.substitute_var_lb, transBlock.substitute_var_ub) = (
+                compute_bounds_on_expr(linear_func_expr)
+            )
+        else:
+            # Add the disjunction
+            transBlock.disj = self._get_disjunction(
+                choices, transBlock, pw_expr, pw_linear_func, transBlock
+            )
+
+        # Set bounds as determined when setting up the disjunction
+        if transBlock.substitute_var_lb < float("inf"):
+            transBlock.substitute_var.setlb(transBlock.substitute_var_lb)
+        if transBlock.substitute_var_ub > -float("inf"):
+            transBlock.substitute_var.setub(transBlock.substitute_var_ub)
+
+        return substitute_var
+
+    # Recursively form the Disjunctions and Disjuncts. This shouldn't blow up
+    # the stack, since the whole point is that we'll only go logarithmically
+    # many calls deep.
+    def _get_disjunction(
+        self, choices, parent_block, pw_expr, pw_linear_func, root_block
+    ):
+        size = len(choices)
+
+        # Our base cases will be 3 and 2, since it would be silly to construct
+        # a Disjunction containing only one Disjunct. We can ensure that size
+        # is never 1 unless it was only passed a single choice from the start,
+        # which we can handle before calling.
+        if size > 3:
+            half = size // 2  # (integer divide)
+            # This tree will be slightly heavier on the right side
+            choices_l = choices[:half]
+            choices_r = choices[half:]
+
+            @parent_block.Disjunct()
+            def d_l(b):
+                b.inner_disjunction_l = self._get_disjunction(
+                    choices_l, b, pw_expr, pw_linear_func, root_block
+                )
+
+            @parent_block.Disjunct()
+            def d_r(b):
+                b.inner_disjunction_r = self._get_disjunction(
+                    choices_r, b, pw_expr, pw_linear_func, root_block
+                )
+
+            return Disjunction(expr=[parent_block.d_l, parent_block.d_r])
+        elif size == 3:
+            # Let's stay heavier on the right side for consistency. So the left
+            # Disjunct will be the one to contain constraints, rather than a
+            # Disjunction
+            @parent_block.Disjunct()
+            def d_l(b):
+                simplex, linear_func = choices[0]
+                self._set_disjunct_block_constraints(
+                    b, simplex, linear_func, pw_expr, pw_linear_func, root_block
+                )
+
+            @parent_block.Disjunct()
+            def d_r(b):
+                b.inner_disjunction_r = self._get_disjunction(
+                    choices[1:], b, pw_expr, pw_linear_func, root_block
+                )
+
+            return Disjunction(expr=[parent_block.d_l, parent_block.d_r])
+        elif size == 2:
+            # In this case both sides are regular Disjuncts
+            @parent_block.Disjunct()
+            def d_l(b):
+                simplex, linear_func = choices[0]
+                self._set_disjunct_block_constraints(
+                    b, simplex, linear_func, pw_expr, pw_linear_func, root_block
+                )
+
+            @parent_block.Disjunct()
+            def d_r(b):
+                simplex, linear_func = choices[1]
+                self._set_disjunct_block_constraints(
+                    b, simplex, linear_func, pw_expr, pw_linear_func, root_block
+                )
+
+            return Disjunction(expr=[parent_block.d_l, parent_block.d_r])
+        else:
+            raise DeveloperError(
+                "Unreachable: 1 or 0 choices were passed to "
+                "_get_disjunction in nested_inner_repn.py."
+            )
+
+    def _set_disjunct_block_constraints(
+        self, b, simplex, linear_func, pw_expr, pw_linear_func, root_block
+    ):
+        # Define the lambdas sparsely like in the normal inner repn,
+        # only the first few will participate in constraints
+        b.lambdas = Var(NonNegativeIntegers, dense=False, bounds=(0, 1))
+
+        # Get the extreme points to add up
+        extreme_pts = []
+        for idx in simplex:
+            extreme_pts.append(pw_linear_func._points[idx])
+
+        # Constrain sum(lambda_i) = 1
+        b.convex_combo = Constraint(
+            expr=sum(b.lambdas[i] for i in range(len(extreme_pts))) == 1
+        )
+        linear_func_expr = linear_func(*pw_expr.args)
+
+        # Make the substitute Var equal the PWLE
+        b.set_substitute = Constraint(
+            expr=root_block.substitute_var == linear_func_expr
+        )
+
+        # Widen the variable bounds to those of this linear func expression
+        (lb, ub) = compute_bounds_on_expr(linear_func_expr)
+        if lb is not None and lb < root_block.substitute_var_lb:
+            root_block.substitute_var_lb = lb
+        if ub is not None and ub > root_block.substitute_var_ub:
+            root_block.substitute_var_ub = ub
+
+        # Constrain x = \sum \lambda_i v_i
+        @b.Constraint(range(pw_expr.nargs()))  # dimension
+        def linear_combo(d, i):
+            return pw_expr.args[i] == sum(
+                d.lambdas[j] * pt[i] for j, pt in enumerate(extreme_pts)
+            )
+
+        # Mark the lambdas as local in order to prevent disagreggating multiple
+        # times in the hull transformation
+        b.LocalVars = Suffix(direction=Suffix.LOCAL)
+        b.LocalVars[b] = [v for v in b.lambdas.values()]
diff --git a/pyomo/contrib/piecewise/transform/outer_representation_gdp.py b/pyomo/contrib/piecewise/transform/outer_representation_gdp.py
index 04cd01e1246..6c26772fe6a 100644
--- a/pyomo/contrib/piecewise/transform/outer_representation_gdp.py
+++ b/pyomo/contrib/piecewise/transform/outer_representation_gdp.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -12,8 +12,8 @@
 import pyomo.common.dependencies.numpy as np
 from pyomo.common.dependencies.scipy import spatial
 from pyomo.contrib.fbbt.fbbt import compute_bounds_on_expr
-from pyomo.contrib.piecewise.transform.piecewise_to_gdp_transformation import (
-    PiecewiseLinearToGDP,
+from pyomo.contrib.piecewise.transform.piecewise_linear_transformation_base import (
+    PiecewiseLinearTransformationBase,
 )
 from pyomo.core import Constraint, NonNegativeIntegers, Suffix, Var
 from pyomo.core.base import TransformationFactory
@@ -27,7 +27,7 @@
     "the simplices that are the domains of the "
     "linear functions.",
 )
-class OuterRepresentationGDPTransformation(PiecewiseLinearToGDP):
+class OuterRepresentationGDPTransformation(PiecewiseLinearTransformationBase):
     """
     Convert a model involving piecewise linear expressions into a GDP by
     representing the piecewise linear functions as Disjunctions where the
@@ -49,7 +49,7 @@ class OuterRepresentationGDPTransformation(PiecewiseLinearToGDP):
            this mode, targets must be Blocks, Constraints, and/or Objectives.
     """
 
-    CONFIG = PiecewiseLinearToGDP.CONFIG()
+    CONFIG = PiecewiseLinearTransformationBase.CONFIG()
     _transformation_name = 'pw_linear_outer_repn'
 
     def _transform_pw_linear_expr(self, pw_expr, pw_linear_func, transformation_block):
diff --git a/pyomo/contrib/piecewise/transform/piecewise_to_gdp_transformation.py b/pyomo/contrib/piecewise/transform/piecewise_linear_transformation_base.py
similarity index 98%
rename from pyomo/contrib/piecewise/transform/piecewise_to_gdp_transformation.py
rename to pyomo/contrib/piecewise/transform/piecewise_linear_transformation_base.py
index ed4902ae6d5..7e96891bbc4 100644
--- a/pyomo/contrib/piecewise/transform/piecewise_to_gdp_transformation.py
+++ b/pyomo/contrib/piecewise/transform/piecewise_linear_transformation_base.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -33,14 +33,14 @@
     Any,
 )
 from pyomo.core.base import Transformation
-from pyomo.core.base.block import _BlockData, Block
+from pyomo.core.base.block import Block
 from pyomo.core.util import target_list
 from pyomo.gdp import Disjunct, Disjunction
 from pyomo.gdp.util import is_child_of
 from pyomo.network import Port
 
 
-class PiecewiseLinearToGDP(Transformation):
+class PiecewiseLinearTransformationBase(Transformation):
     """
     Base class for transformations of piecewise-linear models to GDPs
     """
@@ -147,7 +147,7 @@ def _apply_to_impl(self, instance, **kwds):
                 self._transform_piecewise_linear_function(
                     t, config.descend_into_expressions
                 )
-            elif t.ctype is Block or isinstance(t, _BlockData):
+            elif issubclass(t.ctype, Block):
                 self._transform_block(t, config.descend_into_expressions)
             elif t.ctype is Constraint:
                 if not config.descend_into_expressions:
diff --git a/pyomo/contrib/piecewise/transform/piecewise_to_mip_visitor.py b/pyomo/contrib/piecewise/transform/piecewise_to_mip_visitor.py
index e3347cf206a..fae95a564bf 100644
--- a/pyomo/contrib/piecewise/transform/piecewise_to_mip_visitor.py
+++ b/pyomo/contrib/piecewise/transform/piecewise_to_mip_visitor.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/piecewise/transform/reduced_inner_representation_gdp.py b/pyomo/contrib/piecewise/transform/reduced_inner_representation_gdp.py
index b89852530d9..a19507a93fd 100644
--- a/pyomo/contrib/piecewise/transform/reduced_inner_representation_gdp.py
+++ b/pyomo/contrib/piecewise/transform/reduced_inner_representation_gdp.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -10,8 +10,8 @@
 #  ___________________________________________________________________________
 
 from pyomo.contrib.fbbt.fbbt import compute_bounds_on_expr
-from pyomo.contrib.piecewise.transform.piecewise_to_gdp_transformation import (
-    PiecewiseLinearToGDP,
+from pyomo.contrib.piecewise.transform.piecewise_linear_transformation_base import (
+    PiecewiseLinearTransformationBase,
 )
 from pyomo.core import Constraint, NonNegativeIntegers, Var
 from pyomo.core.base import TransformationFactory
@@ -25,7 +25,7 @@
     "simplices that are the domains of the linear "
     "functions.",
 )
-class ReducedInnerRepresentationGDPTransformation(PiecewiseLinearToGDP):
+class ReducedInnerRepresentationGDPTransformation(PiecewiseLinearTransformationBase):
     """
     Convert a model involving piecewise linear expressions into a GDP by
     representing the piecewise linear functions as Disjunctions where the
@@ -51,7 +51,7 @@ class ReducedInnerRepresentationGDPTransformation(PiecewiseLinearToGDP):
            this mode, targets must be Blocks, Constraints, and/or Objectives.
     """
 
-    CONFIG = PiecewiseLinearToGDP.CONFIG()
+    CONFIG = PiecewiseLinearTransformationBase.CONFIG()
     _transformation_name = 'pw_linear_reduced_inner_repn'
 
     def _transform_pw_linear_expr(self, pw_expr, pw_linear_func, transformation_block):
diff --git a/pyomo/contrib/preprocessing/__init__.py b/pyomo/contrib/preprocessing/__init__.py
index dcd444ad312..6458b7a6e71 100644
--- a/pyomo/contrib/preprocessing/__init__.py
+++ b/pyomo/contrib/preprocessing/__init__.py
@@ -1 +1,12 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.contrib.preprocessing.plugins
diff --git a/pyomo/contrib/preprocessing/plugins/__init__.py b/pyomo/contrib/preprocessing/plugins/__init__.py
index 12eee351308..62f5a40c6a9 100644
--- a/pyomo/contrib/preprocessing/plugins/__init__.py
+++ b/pyomo/contrib/preprocessing/plugins/__init__.py
@@ -1,3 +1,15 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+
 def load():
     import pyomo.contrib.preprocessing.plugins.deactivate_trivial_constraints
     import pyomo.contrib.preprocessing.plugins.detect_fixed_vars
diff --git a/pyomo/contrib/preprocessing/plugins/bounds_to_vars.py b/pyomo/contrib/preprocessing/plugins/bounds_to_vars.py
index 33eaa731816..8cc17296ac3 100644
--- a/pyomo/contrib/preprocessing/plugins/bounds_to_vars.py
+++ b/pyomo/contrib/preprocessing/plugins/bounds_to_vars.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/preprocessing/plugins/constraint_tightener.py b/pyomo/contrib/preprocessing/plugins/constraint_tightener.py
index 4c8b28e0319..73851bce618 100644
--- a/pyomo/contrib/preprocessing/plugins/constraint_tightener.py
+++ b/pyomo/contrib/preprocessing/plugins/constraint_tightener.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import logging
 
 from pyomo.common import deprecated
diff --git a/pyomo/contrib/preprocessing/plugins/deactivate_trivial_constraints.py b/pyomo/contrib/preprocessing/plugins/deactivate_trivial_constraints.py
index a91e0a292f2..59e475e9ba1 100644
--- a/pyomo/contrib/preprocessing/plugins/deactivate_trivial_constraints.py
+++ b/pyomo/contrib/preprocessing/plugins/deactivate_trivial_constraints.py
@@ -2,7 +2,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/preprocessing/plugins/detect_fixed_vars.py b/pyomo/contrib/preprocessing/plugins/detect_fixed_vars.py
index 0832b4b1515..89946fe1529 100644
--- a/pyomo/contrib/preprocessing/plugins/detect_fixed_vars.py
+++ b/pyomo/contrib/preprocessing/plugins/detect_fixed_vars.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/preprocessing/plugins/equality_propagate.py b/pyomo/contrib/preprocessing/plugins/equality_propagate.py
index 03e2e11dadb..357a556fcb2 100644
--- a/pyomo/contrib/preprocessing/plugins/equality_propagate.py
+++ b/pyomo/contrib/preprocessing/plugins/equality_propagate.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/preprocessing/plugins/induced_linearity.py b/pyomo/contrib/preprocessing/plugins/induced_linearity.py
index 6378c94e44e..ba291070644 100644
--- a/pyomo/contrib/preprocessing/plugins/induced_linearity.py
+++ b/pyomo/contrib/preprocessing/plugins/induced_linearity.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/preprocessing/plugins/init_vars.py b/pyomo/contrib/preprocessing/plugins/init_vars.py
index 7469722cf23..a81d898d52c 100644
--- a/pyomo/contrib/preprocessing/plugins/init_vars.py
+++ b/pyomo/contrib/preprocessing/plugins/init_vars.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/preprocessing/plugins/int_to_binary.py b/pyomo/contrib/preprocessing/plugins/int_to_binary.py
index 6ed6c3a9cfa..e1f7f98a81b 100644
--- a/pyomo/contrib/preprocessing/plugins/int_to_binary.py
+++ b/pyomo/contrib/preprocessing/plugins/int_to_binary.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """Transformation to reformulate integer variables into binary."""
 
 from math import floor, log
diff --git a/pyomo/contrib/preprocessing/plugins/remove_zero_terms.py b/pyomo/contrib/preprocessing/plugins/remove_zero_terms.py
index 256c94d4b7a..ca2052fa471 100644
--- a/pyomo/contrib/preprocessing/plugins/remove_zero_terms.py
+++ b/pyomo/contrib/preprocessing/plugins/remove_zero_terms.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/preprocessing/plugins/strip_bounds.py b/pyomo/contrib/preprocessing/plugins/strip_bounds.py
index 51704bc9d58..196de64e405 100644
--- a/pyomo/contrib/preprocessing/plugins/strip_bounds.py
+++ b/pyomo/contrib/preprocessing/plugins/strip_bounds.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/preprocessing/plugins/var_aggregator.py b/pyomo/contrib/preprocessing/plugins/var_aggregator.py
index 651c0ecf7e0..3430d29de3a 100644
--- a/pyomo/contrib/preprocessing/plugins/var_aggregator.py
+++ b/pyomo/contrib/preprocessing/plugins/var_aggregator.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -13,7 +13,14 @@
 
 
 from pyomo.common.collections import ComponentMap, ComponentSet
-from pyomo.core.base import Block, Constraint, VarList, Objective, TransformationFactory
+from pyomo.core.base import (
+    Block,
+    Constraint,
+    VarList,
+    Objective,
+    Reals,
+    TransformationFactory,
+)
 from pyomo.core.expr import ExpressionReplacementVisitor
 from pyomo.core.expr.numvalue import value
 from pyomo.core.plugins.transform.hierarchy import IsomorphicTransformation
@@ -248,6 +255,12 @@ def _apply_to(self, model, detect_fixed_vars=True):
             # the variables in its equality set.
             z_agg.setlb(max_if_not_None(v.lb for v in eq_set if v.has_lb()))
             z_agg.setub(min_if_not_None(v.ub for v in eq_set if v.has_ub()))
+            # Set the domain of the aggregate variable to the intersection of
+            # the domains of the variables in its equality set
+            domain = Reals
+            for v in eq_set:
+                domain = domain & v.domain
+            z_agg.domain = domain
 
             # Set the fixed status of the aggregate var
             fixed_vars = [v for v in eq_set if v.fixed]
diff --git a/pyomo/contrib/preprocessing/plugins/zero_sum_propagator.py b/pyomo/contrib/preprocessing/plugins/zero_sum_propagator.py
index 16c6614cb3b..df6867719d2 100644
--- a/pyomo/contrib/preprocessing/plugins/zero_sum_propagator.py
+++ b/pyomo/contrib/preprocessing/plugins/zero_sum_propagator.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/preprocessing/tests/__init__.py b/pyomo/contrib/preprocessing/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/preprocessing/tests/__init__.py
+++ b/pyomo/contrib/preprocessing/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/preprocessing/tests/test_bounds_to_vars_xfrm.py b/pyomo/contrib/preprocessing/tests/test_bounds_to_vars_xfrm.py
index c2b8acd3e49..0df9dd2462d 100644
--- a/pyomo/contrib/preprocessing/tests/test_bounds_to_vars_xfrm.py
+++ b/pyomo/contrib/preprocessing/tests/test_bounds_to_vars_xfrm.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """Tests explicit bound to variable bound transformation module."""
 
 import pyomo.common.unittest as unittest
diff --git a/pyomo/contrib/preprocessing/tests/test_constraint_tightener.py b/pyomo/contrib/preprocessing/tests/test_constraint_tightener.py
index 8f36bee15a1..acb939552f8 100644
--- a/pyomo/contrib/preprocessing/tests/test_constraint_tightener.py
+++ b/pyomo/contrib/preprocessing/tests/test_constraint_tightener.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """Tests the Bounds Tightening module."""
 
 import pyomo.common.unittest as unittest
diff --git a/pyomo/contrib/preprocessing/tests/test_deactivate_trivial_constraints.py b/pyomo/contrib/preprocessing/tests/test_deactivate_trivial_constraints.py
index fa0ca6cfa9a..9e26aab8b77 100644
--- a/pyomo/contrib/preprocessing/tests/test_deactivate_trivial_constraints.py
+++ b/pyomo/contrib/preprocessing/tests/test_deactivate_trivial_constraints.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # -*- coding: utf-8 -*-
 """Tests deactivation of trivial constraints."""
 import pyomo.common.unittest as unittest
diff --git a/pyomo/contrib/preprocessing/tests/test_detect_fixed_vars.py b/pyomo/contrib/preprocessing/tests/test_detect_fixed_vars.py
index b3c72531f77..a67291dc69f 100644
--- a/pyomo/contrib/preprocessing/tests/test_detect_fixed_vars.py
+++ b/pyomo/contrib/preprocessing/tests/test_detect_fixed_vars.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """Tests detection of fixed variables."""
 
 import pyomo.common.unittest as unittest
diff --git a/pyomo/contrib/preprocessing/tests/test_equality_propagate.py b/pyomo/contrib/preprocessing/tests/test_equality_propagate.py
index b77f5c5f3f5..6b12f464710 100644
--- a/pyomo/contrib/preprocessing/tests/test_equality_propagate.py
+++ b/pyomo/contrib/preprocessing/tests/test_equality_propagate.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """Tests the equality set propagation module."""
 
 import pyomo.common.unittest as unittest
diff --git a/pyomo/contrib/preprocessing/tests/test_induced_linearity.py b/pyomo/contrib/preprocessing/tests/test_induced_linearity.py
index c2c24c33f14..4853cb838df 100644
--- a/pyomo/contrib/preprocessing/tests/test_induced_linearity.py
+++ b/pyomo/contrib/preprocessing/tests/test_induced_linearity.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/preprocessing/tests/test_init_vars.py b/pyomo/contrib/preprocessing/tests/test_init_vars.py
index e52c9fd5cc8..a90d39af91c 100644
--- a/pyomo/contrib/preprocessing/tests/test_init_vars.py
+++ b/pyomo/contrib/preprocessing/tests/test_init_vars.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """Tests initialization of uninitialized variables."""
 
 import pyomo.common.unittest as unittest
diff --git a/pyomo/contrib/preprocessing/tests/test_int_to_binary.py b/pyomo/contrib/preprocessing/tests/test_int_to_binary.py
index bb75a075592..8aa244212ed 100644
--- a/pyomo/contrib/preprocessing/tests/test_int_to_binary.py
+++ b/pyomo/contrib/preprocessing/tests/test_int_to_binary.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/preprocessing/tests/test_strip_bounds.py b/pyomo/contrib/preprocessing/tests/test_strip_bounds.py
index a8526c613c4..f36ff4e9f52 100644
--- a/pyomo/contrib/preprocessing/tests/test_strip_bounds.py
+++ b/pyomo/contrib/preprocessing/tests/test_strip_bounds.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """Tests stripping of variable bounds."""
 
 import pyomo.common.unittest as unittest
diff --git a/pyomo/contrib/preprocessing/tests/test_var_aggregator.py b/pyomo/contrib/preprocessing/tests/test_var_aggregator.py
index 1f2c06dd0d1..b0b672b76b0 100644
--- a/pyomo/contrib/preprocessing/tests/test_var_aggregator.py
+++ b/pyomo/contrib/preprocessing/tests/test_var_aggregator.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """Tests the variable aggregation module."""
 
 import pyomo.common.unittest as unittest
@@ -8,12 +19,16 @@
     max_if_not_None,
     min_if_not_None,
 )
+from pyomo.core.expr.compare import assertExpressionsEqual
 from pyomo.environ import (
+    Binary,
     ConcreteModel,
     Constraint,
     ConstraintList,
+    maximize,
     Objective,
     RangeSet,
+    Reals,
     SolverFactory,
     TransformationFactory,
     Var,
@@ -199,6 +214,36 @@ def test_var_update(self):
         self.assertEqual(m.x.value, 0)
         self.assertEqual(m.y.value, 0)
 
+    def test_binary_inequality(self):
+        m = ConcreteModel()
+        m.x = Var(domain=Binary)
+        m.y = Var(domain=Binary)
+        m.c = Constraint(expr=m.x == m.y)
+        m.o = Objective(expr=0.5 * m.x + m.y, sense=maximize)
+        TransformationFactory('contrib.aggregate_vars').apply_to(m)
+        var_to_z = m._var_aggregator_info.var_to_z
+        z = var_to_z[m.x]
+        self.assertIs(var_to_z[m.y], z)
+        self.assertEqual(z.domain, Binary)
+        self.assertEqual(z.lb, 0)
+        self.assertEqual(z.ub, 1)
+        assertExpressionsEqual(self, m.o.expr, 0.5 * z + z)
+
+    def test_equality_different_domains(self):
+        m = ConcreteModel()
+        m.x = Var(domain=Reals, bounds=(1, 2))
+        m.y = Var(domain=Binary)
+        m.c = Constraint(expr=m.x == m.y)
+        m.o = Objective(expr=0.5 * m.x + m.y, sense=maximize)
+        TransformationFactory('contrib.aggregate_vars').apply_to(m)
+        var_to_z = m._var_aggregator_info.var_to_z
+        z = var_to_z[m.x]
+        self.assertIs(var_to_z[m.y], z)
+        self.assertEqual(z.lb, 1)
+        self.assertEqual(z.ub, 1)
+        self.assertEqual(z.domain, Binary)
+        assertExpressionsEqual(self, m.o.expr, 0.5 * z + z)
+
 
 if __name__ == '__main__':
     unittest.main()
diff --git a/pyomo/contrib/preprocessing/tests/test_zero_sum_propagate.py b/pyomo/contrib/preprocessing/tests/test_zero_sum_propagate.py
index bec889c7635..41ece8e804f 100644
--- a/pyomo/contrib/preprocessing/tests/test_zero_sum_propagate.py
+++ b/pyomo/contrib/preprocessing/tests/test_zero_sum_propagate.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """Tests the zero sum propagation module."""
 
 import pyomo.common.unittest as unittest
diff --git a/pyomo/contrib/preprocessing/tests/test_zero_term_removal.py b/pyomo/contrib/preprocessing/tests/test_zero_term_removal.py
index d1b74822747..c5b7477c8f6 100644
--- a/pyomo/contrib/preprocessing/tests/test_zero_term_removal.py
+++ b/pyomo/contrib/preprocessing/tests/test_zero_term_removal.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """Tests detection of zero terms."""
 
 import pyomo.common.unittest as unittest
diff --git a/pyomo/contrib/preprocessing/util.py b/pyomo/contrib/preprocessing/util.py
index 69182f56656..13f3e5dd18c 100644
--- a/pyomo/contrib/preprocessing/util.py
+++ b/pyomo/contrib/preprocessing/util.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import logging
 
 from io import StringIO
diff --git a/pyomo/contrib/pynumero/README.md b/pyomo/contrib/pynumero/README.md
index 0d165dbc39c..f881e400d51 100644
--- a/pyomo/contrib/pynumero/README.md
+++ b/pyomo/contrib/pynumero/README.md
@@ -71,3 +71,75 @@ Prerequisites
    - cmake
    - a C/C++ compiler
    - MA57 library or COIN-HSL Full
+
+Code organization
+=================
+
+PyNumero was initially designed around three core components: linear solver
+interfaces, an interface for function and derivative callbacks, and block
+vector and matrix classes. Since then, it has incorporated additional
+functionality in an ad-hoc manner. The original "core functionality" of
+PyNumero, as well as the solver interfaces accessible through
+`SolverFactory`, should be considered stable and will only change after
+appropriate deprecation warnings. Other functionality should be considered
+experimental and subject to change without warning.
+
+The following is a rough overview of PyNumero, by directory:
+
+`linalg`
+--------
+
+Python interfaces to linear solvers. This is core functionality.
+
+`interfaces`
+------------
+
+- Classes that define and implement an API for function and derivative callbacks
+required by nonlinear optimization solvers, e.g. `nlp.py` and `pyomo_nlp.py`
+- Various wrappers around these NLP classes to support "hybrid" implementations,
+e.g. `PyomoNLPWithGreyBoxBlocks`
+- The `ExternalGreyBoxBlock` Pyomo modeling component and
+`ExternalGreyBoxModel` API
+- The `ExternalPyomoModel` implementation of `ExternalGreyBoxModel`, which allows
+definition of an external grey box via an implicit function
+- The `CyIpoptNLP` class, which wraps an object implementing the NLP API in
+the interface required by CyIpopt
+
+Of the above, only `PyomoNLP` and the `NLP` base class should be considered core
+functionality.
+
+`src`
+-----
+
+C++ interfaces to ASL, MA27, and MA57. The ASL and MA27 interfaces are
+core functionality.
+
+`sparse`
+--------
+
+Block vector and block matrix classes, including MPI variations.
+These are core functionality.
+
+`algorithms`
+------------
+
+Originally intended to hold various useful algorithms implemented
+on NLP objects rather than Pyomo models. Any files added here should
+be considered experimental.
+
+`algorithms/solvers`
+--------------------
+
+Interfaces to Python solvers using the NLP API defined in `interfaces`.
+Only the solvers accessible through `SolverFactory`, e.g. `PyomoCyIpoptSolver`
+and `PyomoFsolveSolver`, should be considered core functionality.
+The supported way to access these solvers is via `SolverFactory`. *The locations
+of the underlying solver objects are subject to change without warning.*
+
+`examples`
+----------
+
+The examples demonstrated in `nlp_interface.py`, `nlp_interface_2.py1`,
+`feasibility.py`, `mumps_example.py`, `sensitivity.py`, `sqp.py`,
+`parallel_matvec.py`, and `parallel_vector_ops.py` are stable. All other
+examples should be considered experimental.
diff --git a/pyomo/contrib/pynumero/__init__.py b/pyomo/contrib/pynumero/__init__.py
index 9364a552999..39ee2197cbf 100644
--- a/pyomo/contrib/pynumero/__init__.py
+++ b/pyomo/contrib/pynumero/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/algorithms/__init__.py b/pyomo/contrib/pynumero/algorithms/__init__.py
index d93cfd77b3c..a4a626013c4 100644
--- a/pyomo/contrib/pynumero/algorithms/__init__.py
+++ b/pyomo/contrib/pynumero/algorithms/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/algorithms/solvers/__init__.py b/pyomo/contrib/pynumero/algorithms/solvers/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/pynumero/algorithms/solvers/__init__.py
+++ b/pyomo/contrib/pynumero/algorithms/solvers/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/pynumero/algorithms/solvers/cyipopt_solver.py b/pyomo/contrib/pynumero/algorithms/solvers/cyipopt_solver.py
index cedbf430a12..0999550711c 100644
--- a/pyomo/contrib/pynumero/algorithms/solvers/cyipopt_solver.py
+++ b/pyomo/contrib/pynumero/algorithms/solvers/cyipopt_solver.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -24,6 +24,8 @@
 from pyomo.common.deprecation import relocated_module_attribute
 from pyomo.common.dependencies import attempt_import, numpy as np, numpy_available
 from pyomo.common.tee import redirect_fd, TeeStream
+from pyomo.common.modeling import unique_component_name
+from pyomo.core.base.objective import Objective
 
 # Because pynumero.interfaces requires numpy, we will leverage deferred
 # imports here so that the solver can be registered even when numpy is
@@ -63,7 +65,7 @@
 from pyomo.common.config import ConfigBlock, ConfigValue
 from pyomo.common.timing import TicTocTimer
 from pyomo.core.base import Block, Objective, minimize
-from pyomo.opt import SolverStatus, SolverResults, TerminationCondition, ProblemSense
+from pyomo.opt import SolverStatus, SolverResults, TerminationCondition
 from pyomo.opt.results.solution import Solution
 
 logger = logging.getLogger(__name__)
@@ -317,7 +319,13 @@ def license_is_valid(self):
         return True
 
     def version(self):
-        return tuple(int(_) for _ in cyipopt.__version__.split("."))
+        def _int(x):
+            try:
+                return int(x)
+            except:
+                return x
+
+        return tuple(_int(_) for _ in cyipopt_interface.cyipopt.__version__.split("."))
 
     def solve(self, model, **kwds):
         config = self.config(kwds, preserve_implicit=True)
@@ -332,11 +340,22 @@ def solve(self, model, **kwds):
         grey_box_blocks = list(
             model.component_data_objects(egb.ExternalGreyBoxBlock, active=True)
         )
-        if grey_box_blocks:
-            # nlp = pyomo_nlp.PyomoGreyBoxNLP(model)
-            nlp = pyomo_grey_box.PyomoNLPWithGreyBoxBlocks(model)
-        else:
-            nlp = pyomo_nlp.PyomoNLP(model)
+        # if there is no objective, add one temporarily so we can construct an NLP
+        objectives = list(model.component_data_objects(Objective, active=True))
+        if not objectives:
+            objname = unique_component_name(model, "_obj")
+            objective = model.add_component(objname, Objective(expr=0.0))
+        try:
+            if grey_box_blocks:
+                # nlp = pyomo_nlp.PyomoGreyBoxNLP(model)
+                nlp = pyomo_grey_box.PyomoNLPWithGreyBoxBlocks(model)
+            else:
+                nlp = pyomo_nlp.PyomoNLP(model)
+        finally:
+            # We only need the objective to construct the NLP, so we delete
+            # it from the model ASAP
+            if not objectives:
+                model.del_component(objective)
 
         problem = cyipopt_interface.CyIpoptNLP(
             nlp,
@@ -428,11 +447,10 @@ def solve(self, model, **kwds):
 
         results.problem.name = model.name
         obj = next(model.component_data_objects(Objective, active=True))
+        results.problem.sense = obj.sense
         if obj.sense == minimize:
-            results.problem.sense = ProblemSense.minimize
             results.problem.upper_bound = info["obj_val"]
         else:
-            results.problem.sense = ProblemSense.maximize
             results.problem.lower_bound = info["obj_val"]
         results.problem.number_of_objectives = 1
         results.problem.number_of_constraints = ng
diff --git a/pyomo/contrib/pynumero/algorithms/solvers/implicit_functions.py b/pyomo/contrib/pynumero/algorithms/solvers/implicit_functions.py
index e0bc0170d33..e40580c1161 100644
--- a/pyomo/contrib/pynumero/algorithms/solvers/implicit_functions.py
+++ b/pyomo/contrib/pynumero/algorithms/solvers/implicit_functions.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/algorithms/solvers/pyomo_ext_cyipopt.py b/pyomo/contrib/pynumero/algorithms/solvers/pyomo_ext_cyipopt.py
index b234d2f0890..7f43f6ac7c0 100644
--- a/pyomo/contrib/pynumero/algorithms/solvers/pyomo_ext_cyipopt.py
+++ b/pyomo/contrib/pynumero/algorithms/solvers/pyomo_ext_cyipopt.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -16,7 +16,7 @@
 from pyomo.contrib.pynumero.interfaces.pyomo_nlp import PyomoNLP
 from pyomo.contrib.pynumero.sparse.block_vector import BlockVector
 from pyomo.environ import Var, Constraint, value
-from pyomo.core.base.var import _VarData
+from pyomo.core.base.var import VarData
 from pyomo.common.modeling import unique_component_name
 
 """
@@ -109,12 +109,12 @@ def __init__(
            An instance of a derived class (from ExternalInputOutputModel) that provides
            the methods to compute the outputs and the derivatives.
 
-        inputs : list of Pyomo variables (_VarData)
+        inputs : list of Pyomo variables (VarData)
            The Pyomo model needs to have variables to represent the inputs to the
            external model. This is the list of those input variables in the order
            that corresponds to the input_values vector provided in the set_inputs call.
 
-        outputs : list of Pyomo variables (_VarData)
+        outputs : list of Pyomo variables (VarData)
           The Pyomo model needs to have variables to represent the outputs from the
           external model. This is the list of those output variables in the order
           that corresponds to the numpy array returned from the evaluate_outputs call.
@@ -130,7 +130,7 @@ def __init__(
         # verify that the inputs and outputs were passed correctly
         self._inputs = [v for v in inputs]
         for v in self._inputs:
-            if not isinstance(v, _VarData):
+            if not isinstance(v, VarData):
                 raise RuntimeError(
                     'Argument inputs passed to PyomoExternalCyIpoptProblem must be'
                     ' a list of VarData objects. Note: if you have an indexed variable, pass'
@@ -139,7 +139,7 @@ def __init__(
 
         self._outputs = [v for v in outputs]
         for v in self._outputs:
-            if not isinstance(v, _VarData):
+            if not isinstance(v, VarData):
                 raise RuntimeError(
                     'Argument outputs passed to PyomoExternalCyIpoptProblem must be'
                     ' a list of VarData objects. Note: if you have an indexed variable, pass'
diff --git a/pyomo/contrib/pynumero/algorithms/solvers/scipy_solvers.py b/pyomo/contrib/pynumero/algorithms/solvers/scipy_solvers.py
index 53f657c984f..ec1f106b73c 100644
--- a/pyomo/contrib/pynumero/algorithms/solvers/scipy_solvers.py
+++ b/pyomo/contrib/pynumero/algorithms/solvers/scipy_solvers.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/algorithms/solvers/square_solver_base.py b/pyomo/contrib/pynumero/algorithms/solvers/square_solver_base.py
index c4a33d97611..1be3032c358 100644
--- a/pyomo/contrib/pynumero/algorithms/solvers/square_solver_base.py
+++ b/pyomo/contrib/pynumero/algorithms/solvers/square_solver_base.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/algorithms/solvers/tests/__init__.py b/pyomo/contrib/pynumero/algorithms/solvers/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/pynumero/algorithms/solvers/tests/__init__.py
+++ b/pyomo/contrib/pynumero/algorithms/solvers/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/pynumero/algorithms/solvers/tests/test_cyipopt_interfaces.py b/pyomo/contrib/pynumero/algorithms/solvers/tests/test_cyipopt_interfaces.py
index 119c4604f19..88d4df1e17d 100644
--- a/pyomo/contrib/pynumero/algorithms/solvers/tests/test_cyipopt_interfaces.py
+++ b/pyomo/contrib/pynumero/algorithms/solvers/tests/test_cyipopt_interfaces.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/algorithms/solvers/tests/test_cyipopt_solver.py b/pyomo/contrib/pynumero/algorithms/solvers/tests/test_cyipopt_solver.py
index 7ead30117cb..0af5a772c98 100644
--- a/pyomo/contrib/pynumero/algorithms/solvers/tests/test_cyipopt_solver.py
+++ b/pyomo/contrib/pynumero/algorithms/solvers/tests/test_cyipopt_solver.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -316,3 +316,13 @@ def test_hs071_evalerror_old_cyipopt(self):
         msg = "Error in AMPL evaluation"
         with self.assertRaisesRegex(PyNumeroEvaluationError, msg):
             res = solver.solve(m, tee=True)
+
+    def test_solve_without_objective(self):
+        m = create_model1()
+        m.o.deactivate()
+        m.x[2].fix(0.0)
+        m.x[3].fix(4.0)
+        solver = pyo.SolverFactory("cyipopt")
+        res = solver.solve(m, tee=True)
+        pyo.assert_optimal_termination(res)
+        self.assertAlmostEqual(m.x[1].value, 9.0)
diff --git a/pyomo/contrib/pynumero/algorithms/solvers/tests/test_implicit_functions.py b/pyomo/contrib/pynumero/algorithms/solvers/tests/test_implicit_functions.py
index 04d4ed321f1..3a13c1a7598 100644
--- a/pyomo/contrib/pynumero/algorithms/solvers/tests/test_implicit_functions.py
+++ b/pyomo/contrib/pynumero/algorithms/solvers/tests/test_implicit_functions.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/algorithms/solvers/tests/test_pyomo_ext_cyipopt.py b/pyomo/contrib/pynumero/algorithms/solvers/tests/test_pyomo_ext_cyipopt.py
index 82a37873d5f..0036a6b3623 100644
--- a/pyomo/contrib/pynumero/algorithms/solvers/tests/test_pyomo_ext_cyipopt.py
+++ b/pyomo/contrib/pynumero/algorithms/solvers/tests/test_pyomo_ext_cyipopt.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/algorithms/solvers/tests/test_scipy_solvers.py b/pyomo/contrib/pynumero/algorithms/solvers/tests/test_scipy_solvers.py
index 6636dc3d6e2..33b58f17887 100644
--- a/pyomo/contrib/pynumero/algorithms/solvers/tests/test_scipy_solvers.py
+++ b/pyomo/contrib/pynumero/algorithms/solvers/tests/test_scipy_solvers.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/asl.py b/pyomo/contrib/pynumero/asl.py
index a28741fb230..55ecc7fd0ee 100644
--- a/pyomo/contrib/pynumero/asl.py
+++ b/pyomo/contrib/pynumero/asl.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/build.py b/pyomo/contrib/pynumero/build.py
index 08b5c512ab7..bb8443640d5 100644
--- a/pyomo/contrib/pynumero/build.py
+++ b/pyomo/contrib/pynumero/build.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/dependencies.py b/pyomo/contrib/pynumero/dependencies.py
index d386bbc3dda..d323bd43e84 100644
--- a/pyomo/contrib/pynumero/dependencies.py
+++ b/pyomo/contrib/pynumero/dependencies.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -17,7 +17,7 @@
     'numpy',
     'Pynumero requires the optional Pyomo dependency "numpy"',
     minimum_version='1.13.0',
-    defer_check=False,
+    defer_import=False,
 )
 
 if not numpy_available:
diff --git a/pyomo/contrib/pynumero/examples/__init__.py b/pyomo/contrib/pynumero/examples/__init__.py
index d93cfd77b3c..a4a626013c4 100644
--- a/pyomo/contrib/pynumero/examples/__init__.py
+++ b/pyomo/contrib/pynumero/examples/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/examples/callback/__init__.py b/pyomo/contrib/pynumero/examples/callback/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/pynumero/examples/callback/__init__.py
+++ b/pyomo/contrib/pynumero/examples/callback/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/pynumero/examples/callback/cyipopt_callback.py b/pyomo/contrib/pynumero/examples/callback/cyipopt_callback.py
index 6bd86c006a1..f66374f6213 100644
--- a/pyomo/contrib/pynumero/examples/callback/cyipopt_callback.py
+++ b/pyomo/contrib/pynumero/examples/callback/cyipopt_callback.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 from pyomo.contrib.pynumero.examples.callback.reactor_design import model as m
 import logging
diff --git a/pyomo/contrib/pynumero/examples/callback/cyipopt_callback_halt.py b/pyomo/contrib/pynumero/examples/callback/cyipopt_callback_halt.py
index 18fad2bbcd8..9e88f8d4964 100644
--- a/pyomo/contrib/pynumero/examples/callback/cyipopt_callback_halt.py
+++ b/pyomo/contrib/pynumero/examples/callback/cyipopt_callback_halt.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 from pyomo.contrib.pynumero.examples.callback.reactor_design import model as m
 
diff --git a/pyomo/contrib/pynumero/examples/callback/cyipopt_functor_callback.py b/pyomo/contrib/pynumero/examples/callback/cyipopt_functor_callback.py
index ca452f33c90..4befc816e1b 100644
--- a/pyomo/contrib/pynumero/examples/callback/cyipopt_functor_callback.py
+++ b/pyomo/contrib/pynumero/examples/callback/cyipopt_functor_callback.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 from pyomo.contrib.pynumero.examples.callback.reactor_design import model as m
 from pyomo.common.dependencies import pandas as pd
diff --git a/pyomo/contrib/pynumero/examples/callback/reactor_design.py b/pyomo/contrib/pynumero/examples/callback/reactor_design.py
index 927b25f9bc9..3d9e19a446e 100644
--- a/pyomo/contrib/pynumero/examples/callback/reactor_design.py
+++ b/pyomo/contrib/pynumero/examples/callback/reactor_design.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ
 from pyomo.core import *
 
diff --git a/pyomo/contrib/pynumero/examples/external_grey_box/__init__.py b/pyomo/contrib/pynumero/examples/external_grey_box/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/pynumero/examples/external_grey_box/__init__.py
+++ b/pyomo/contrib/pynumero/examples/external_grey_box/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/pynumero/examples/external_grey_box/param_est/__init__.py b/pyomo/contrib/pynumero/examples/external_grey_box/param_est/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/pynumero/examples/external_grey_box/param_est/__init__.py
+++ b/pyomo/contrib/pynumero/examples/external_grey_box/param_est/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/pynumero/examples/external_grey_box/param_est/generate_data.py b/pyomo/contrib/pynumero/examples/external_grey_box/param_est/generate_data.py
index 5bf0defbb8d..65bb2c82de8 100644
--- a/pyomo/contrib/pynumero/examples/external_grey_box/param_est/generate_data.py
+++ b/pyomo/contrib/pynumero/examples/external_grey_box/param_est/generate_data.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 import numpy.random as rnd
 import pyomo.contrib.pynumero.examples.external_grey_box.param_est.models as pm
diff --git a/pyomo/contrib/pynumero/examples/external_grey_box/param_est/models.py b/pyomo/contrib/pynumero/examples/external_grey_box/param_est/models.py
index a8b9befb188..c6560b4f9c5 100644
--- a/pyomo/contrib/pynumero/examples/external_grey_box/param_est/models.py
+++ b/pyomo/contrib/pynumero/examples/external_grey_box/param_est/models.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.environ as pyo
 from pyomo.contrib.pynumero.interfaces.external_grey_box import (
     ExternalGreyBoxModel,
diff --git a/pyomo/contrib/pynumero/examples/external_grey_box/param_est/perform_estimation.py b/pyomo/contrib/pynumero/examples/external_grey_box/param_est/perform_estimation.py
index f27192f9281..142b47f8172 100644
--- a/pyomo/contrib/pynumero/examples/external_grey_box/param_est/perform_estimation.py
+++ b/pyomo/contrib/pynumero/examples/external_grey_box/param_est/perform_estimation.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import sys
 import pyomo.environ as pyo
 import numpy.random as rnd
diff --git a/pyomo/contrib/pynumero/examples/external_grey_box/react_example/__init__.py b/pyomo/contrib/pynumero/examples/external_grey_box/react_example/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/pynumero/examples/external_grey_box/react_example/__init__.py
+++ b/pyomo/contrib/pynumero/examples/external_grey_box/react_example/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/pynumero/examples/external_grey_box/react_example/maximize_cb_outputs.py b/pyomo/contrib/pynumero/examples/external_grey_box/react_example/maximize_cb_outputs.py
index 9f683b146fe..e6afd8995a2 100644
--- a/pyomo/contrib/pynumero/examples/external_grey_box/react_example/maximize_cb_outputs.py
+++ b/pyomo/contrib/pynumero/examples/external_grey_box/react_example/maximize_cb_outputs.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/examples/external_grey_box/react_example/maximize_cb_ratio_residuals.py b/pyomo/contrib/pynumero/examples/external_grey_box/react_example/maximize_cb_ratio_residuals.py
index 26d70c7921e..415b58bee54 100644
--- a/pyomo/contrib/pynumero/examples/external_grey_box/react_example/maximize_cb_ratio_residuals.py
+++ b/pyomo/contrib/pynumero/examples/external_grey_box/react_example/maximize_cb_ratio_residuals.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/examples/external_grey_box/react_example/reactor_model_outputs.py b/pyomo/contrib/pynumero/examples/external_grey_box/react_example/reactor_model_outputs.py
index 6e6c997880b..ef8b2783237 100644
--- a/pyomo/contrib/pynumero/examples/external_grey_box/react_example/reactor_model_outputs.py
+++ b/pyomo/contrib/pynumero/examples/external_grey_box/react_example/reactor_model_outputs.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/examples/external_grey_box/react_example/reactor_model_residuals.py b/pyomo/contrib/pynumero/examples/external_grey_box/react_example/reactor_model_residuals.py
index 69a79425750..bc5a2ca4ce4 100644
--- a/pyomo/contrib/pynumero/examples/external_grey_box/react_example/reactor_model_residuals.py
+++ b/pyomo/contrib/pynumero/examples/external_grey_box/react_example/reactor_model_residuals.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/examples/feasibility.py b/pyomo/contrib/pynumero/examples/feasibility.py
index 94baabb7bec..59e4edcc9ec 100644
--- a/pyomo/contrib/pynumero/examples/feasibility.py
+++ b/pyomo/contrib/pynumero/examples/feasibility.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/examples/mumps_example.py b/pyomo/contrib/pynumero/examples/mumps_example.py
index 938fab99279..588ce58bc12 100644
--- a/pyomo/contrib/pynumero/examples/mumps_example.py
+++ b/pyomo/contrib/pynumero/examples/mumps_example.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import numpy as np
 import scipy.sparse as sp
 from scipy.linalg import hilbert
diff --git a/pyomo/contrib/pynumero/examples/nlp_interface.py b/pyomo/contrib/pynumero/examples/nlp_interface.py
index 730e0fbda47..556b8ec0713 100644
--- a/pyomo/contrib/pynumero/examples/nlp_interface.py
+++ b/pyomo/contrib/pynumero/examples/nlp_interface.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/examples/nlp_interface_2.py b/pyomo/contrib/pynumero/examples/nlp_interface_2.py
index ecd63d28c49..4a288a178b1 100644
--- a/pyomo/contrib/pynumero/examples/nlp_interface_2.py
+++ b/pyomo/contrib/pynumero/examples/nlp_interface_2.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/examples/parallel_matvec.py b/pyomo/contrib/pynumero/examples/parallel_matvec.py
index 26a2ec9a632..cd77bcfabc9 100644
--- a/pyomo/contrib/pynumero/examples/parallel_matvec.py
+++ b/pyomo/contrib/pynumero/examples/parallel_matvec.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import numpy as np
 from pyomo.common.dependencies import mpi4py
 from pyomo.contrib.pynumero.sparse.mpi_block_vector import MPIBlockVector
diff --git a/pyomo/contrib/pynumero/examples/parallel_vector_ops.py b/pyomo/contrib/pynumero/examples/parallel_vector_ops.py
index 4b155ce7493..fe49ff29e59 100644
--- a/pyomo/contrib/pynumero/examples/parallel_vector_ops.py
+++ b/pyomo/contrib/pynumero/examples/parallel_vector_ops.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import numpy as np
 from pyomo.common.dependencies import mpi4py
 from pyomo.contrib.pynumero.sparse.mpi_block_vector import MPIBlockVector
diff --git a/pyomo/contrib/pynumero/examples/sensitivity.py b/pyomo/contrib/pynumero/examples/sensitivity.py
index a3927d637b3..0bb0fb3a740 100644
--- a/pyomo/contrib/pynumero/examples/sensitivity.py
+++ b/pyomo/contrib/pynumero/examples/sensitivity.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/examples/sqp.py b/pyomo/contrib/pynumero/examples/sqp.py
index 7d321676817..925cab4c20b 100644
--- a/pyomo/contrib/pynumero/examples/sqp.py
+++ b/pyomo/contrib/pynumero/examples/sqp.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.contrib.pynumero.interfaces.nlp import NLP
 from pyomo.contrib.pynumero.sparse import BlockVector, BlockMatrix
 from pyomo.contrib.pynumero.linalg.ma27_interface import MA27
diff --git a/pyomo/contrib/pynumero/examples/tests/__init__.py b/pyomo/contrib/pynumero/examples/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/pynumero/examples/tests/__init__.py
+++ b/pyomo/contrib/pynumero/examples/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/pynumero/examples/tests/test_cyipopt_examples.py b/pyomo/contrib/pynumero/examples/tests/test_cyipopt_examples.py
index 167b0601f7a..2df43c1e797 100644
--- a/pyomo/contrib/pynumero/examples/tests/test_cyipopt_examples.py
+++ b/pyomo/contrib/pynumero/examples/tests/test_cyipopt_examples.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -35,7 +35,7 @@
     'One of the tests below requires a recent version of pandas for'
     ' comparing with a tolerance.',
     minimum_version='1.1.0',
-    defer_check=False,
+    defer_import=False,
 )
 
 from pyomo.contrib.pynumero.asl import AmplInterface
@@ -44,11 +44,13 @@
     raise unittest.SkipTest("Pynumero needs the ASL extension to run CyIpopt tests")
 
 import pyomo.contrib.pynumero.algorithms.solvers.cyipopt_solver as cyipopt_solver
+from pyomo.contrib.pynumero.interfaces.cyipopt_interface import cyipopt_available
 
-if not cyipopt_solver.cyipopt_available:
+if not cyipopt_available:
     raise unittest.SkipTest("PyNumero needs CyIpopt installed to run CyIpopt tests")
 import cyipopt as cyipopt_core
 
+
 example_dir = os.path.join(this_file_dir(), '..')
 
 
@@ -266,6 +268,11 @@ def test_cyipopt_functor(self):
         s = df['ca_bal']
         self.assertAlmostEqual(s.iloc[6], 0, places=3)
 
+    @unittest.skipIf(
+        cyipopt_solver.PyomoCyIpoptSolver().version() == (1, 4, 0),
+        "Terminating Ipopt through a user callback is broken in CyIpopt 1.4.0 "
+        "(see mechmotum/cyipopt#249)",
+    )
     def test_cyipopt_callback_halt(self):
         ex = import_file(
             os.path.join(example_dir, 'callback', 'cyipopt_callback_halt.py')
diff --git a/pyomo/contrib/pynumero/examples/tests/test_examples.py b/pyomo/contrib/pynumero/examples/tests/test_examples.py
index 5c7993ebbb6..d1494bab557 100644
--- a/pyomo/contrib/pynumero/examples/tests/test_examples.py
+++ b/pyomo/contrib/pynumero/examples/tests/test_examples.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.contrib.pynumero.dependencies import numpy_available, scipy_available
 import pyomo.common.unittest as unittest
 
diff --git a/pyomo/contrib/pynumero/examples/tests/test_mpi_examples.py b/pyomo/contrib/pynumero/examples/tests/test_mpi_examples.py
index 68fe907a8ef..1ee02bb70ca 100644
--- a/pyomo/contrib/pynumero/examples/tests/test_mpi_examples.py
+++ b/pyomo/contrib/pynumero/examples/tests/test_mpi_examples.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.common.unittest as unittest
 
 from pyomo.contrib.pynumero.dependencies import (
diff --git a/pyomo/contrib/pynumero/exceptions.py b/pyomo/contrib/pynumero/exceptions.py
index dc2167d75d2..6b46dd2d9a7 100644
--- a/pyomo/contrib/pynumero/exceptions.py
+++ b/pyomo/contrib/pynumero/exceptions.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/interfaces/__init__.py b/pyomo/contrib/pynumero/interfaces/__init__.py
index debe453e175..e2de0dd25cc 100644
--- a/pyomo/contrib/pynumero/interfaces/__init__.py
+++ b/pyomo/contrib/pynumero/interfaces/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/interfaces/ampl_nlp.py b/pyomo/contrib/pynumero/interfaces/ampl_nlp.py
index f5bd56696cf..30258b3e685 100644
--- a/pyomo/contrib/pynumero/interfaces/ampl_nlp.py
+++ b/pyomo/contrib/pynumero/interfaces/ampl_nlp.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -27,10 +27,8 @@
 from pyomo.common.deprecation import deprecated
 from pyomo.contrib.pynumero.interfaces.nlp import ExtendedNLP
 
-__all__ = ['AslNLP', 'AmplNLP']
 
-
-# ToDo: need to add support for modifying bounds.
+# TODO: need to add support for modifying bounds.
 # support for changing variable bounds seems possible.
 # support for changing inequality bounds would require more work. (this is less frequent?)
 # TODO: check performance impacts of caching - memory and computational time.
diff --git a/pyomo/contrib/pynumero/interfaces/cyipopt_interface.py b/pyomo/contrib/pynumero/interfaces/cyipopt_interface.py
index fc9c45c6d1a..7845a4c189e 100644
--- a/pyomo/contrib/pynumero/interfaces/cyipopt_interface.py
+++ b/pyomo/contrib/pynumero/interfaces/cyipopt_interface.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/interfaces/external_grey_box.py b/pyomo/contrib/pynumero/interfaces/external_grey_box.py
index 642fd3bf310..68e652575cc 100644
--- a/pyomo/contrib/pynumero/interfaces/external_grey_box.py
+++ b/pyomo/contrib/pynumero/interfaces/external_grey_box.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -18,7 +18,7 @@
 from pyomo.common.log import is_debug_set
 from pyomo.common.timing import ConstructionTimer
 from pyomo.core.base import Var, Set, Constraint, value
-from pyomo.core.base.block import _BlockData, Block, declare_custom_block
+from pyomo.core.base.block import BlockData, Block, declare_custom_block
 from pyomo.core.base.global_set import UnindexedComponent_index
 from pyomo.core.base.initializer import Initializer
 from pyomo.core.base.set import UnindexedComponent_set
@@ -316,7 +316,7 @@ def evaluate_jacobian_outputs(self):
     #
 
 
-class ExternalGreyBoxBlockData(_BlockData):
+class ExternalGreyBoxBlockData(BlockData):
     def set_external_model(self, external_grey_box_model, inputs=None, outputs=None):
         """
         Parameters
@@ -424,7 +424,7 @@ class ScalarExternalGreyBoxBlock(ExternalGreyBoxBlockData, ExternalGreyBoxBlock)
     def __init__(self, *args, **kwds):
         ExternalGreyBoxBlockData.__init__(self, component=self)
         ExternalGreyBoxBlock.__init__(self, *args, **kwds)
-        # The above inherit from Block and _BlockData, so it's not until here
+        # The above inherit from Block and BlockData, so it's not until here
         # that we know it's scalar. So we set the index accordingly.
         self._index = UnindexedComponent_index
 
diff --git a/pyomo/contrib/pynumero/interfaces/external_pyomo_model.py b/pyomo/contrib/pynumero/interfaces/external_pyomo_model.py
index d0e6c21fa64..bae3e0b8159 100644
--- a/pyomo/contrib/pynumero/interfaces/external_pyomo_model.py
+++ b/pyomo/contrib/pynumero/interfaces/external_pyomo_model.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/interfaces/nlp.py b/pyomo/contrib/pynumero/interfaces/nlp.py
index 95c05f06a61..d6571086429 100644
--- a/pyomo/contrib/pynumero/interfaces/nlp.py
+++ b/pyomo/contrib/pynumero/interfaces/nlp.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -50,9 +50,8 @@
 .. rubric:: Contents
 
 """
-import abc
 
-__all__ = ['NLP']
+import abc
 
 
 class NLP(object, metaclass=abc.ABCMeta):
diff --git a/pyomo/contrib/pynumero/interfaces/nlp_projections.py b/pyomo/contrib/pynumero/interfaces/nlp_projections.py
index 68cb0eef15f..4be3cd28dd5 100644
--- a/pyomo/contrib/pynumero/interfaces/nlp_projections.py
+++ b/pyomo/contrib/pynumero/interfaces/nlp_projections.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.contrib.pynumero.interfaces.nlp import NLP, ExtendedNLP
 import numpy as np
 import scipy.sparse as sp
diff --git a/pyomo/contrib/pynumero/interfaces/pyomo_grey_box_nlp.py b/pyomo/contrib/pynumero/interfaces/pyomo_grey_box_nlp.py
index 945e9a05f51..e6ed40e9974 100644
--- a/pyomo/contrib/pynumero/interfaces/pyomo_grey_box_nlp.py
+++ b/pyomo/contrib/pynumero/interfaces/pyomo_grey_box_nlp.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/interfaces/pyomo_nlp.py b/pyomo/contrib/pynumero/interfaces/pyomo_nlp.py
index 8017c642854..e12d0cf568b 100644
--- a/pyomo/contrib/pynumero/interfaces/pyomo_nlp.py
+++ b/pyomo/contrib/pynumero/interfaces/pyomo_nlp.py
@@ -1,6 +1,6 @@
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -22,15 +22,13 @@
 import pyomo.core.base as pyo
 from pyomo.common.collections import ComponentMap
 from pyomo.common.env import CtypesEnviron
+from pyomo.solvers.amplfunc_merge import amplfunc_merge
 from ..sparse.block_matrix import BlockMatrix
 from pyomo.contrib.pynumero.interfaces.ampl_nlp import AslNLP
 from pyomo.contrib.pynumero.interfaces.nlp import NLP
 from .external_grey_box import ExternalGreyBoxBlock
 
 
-__all__ = ['PyomoNLP']
-
-
 # TODO: There are todos in the code below
 class PyomoNLP(AslNLP):
     def __init__(self, pyomo_model, nl_file_options=None):
@@ -95,15 +93,8 @@ def __init__(self, pyomo_model, nl_file_options=None):
             # The NL writer advertises the external function libraries
             # through the PYOMO_AMPLFUNC environment variable; merge it
             # with any preexisting AMPLFUNC definitions
-            amplfunc = "\n".join(
-                filter(
-                    None,
-                    (
-                        os.environ.get('AMPLFUNC', None),
-                        os.environ.get('PYOMO_AMPLFUNC', None),
-                    ),
-                )
-            )
+            amplfunc = amplfunc_merge(os.environ)
+
             with CtypesEnviron(AMPLFUNC=amplfunc):
                 super(PyomoNLP, self).__init__(nl_file)
 
diff --git a/pyomo/contrib/pynumero/interfaces/tests/__init__.py b/pyomo/contrib/pynumero/interfaces/tests/__init__.py
index d93cfd77b3c..a4a626013c4 100644
--- a/pyomo/contrib/pynumero/interfaces/tests/__init__.py
+++ b/pyomo/contrib/pynumero/interfaces/tests/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/interfaces/tests/compare_utils.py b/pyomo/contrib/pynumero/interfaces/tests/compare_utils.py
index d30cfb8f56a..8296ea2d1af 100644
--- a/pyomo/contrib/pynumero/interfaces/tests/compare_utils.py
+++ b/pyomo/contrib/pynumero/interfaces/tests/compare_utils.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/interfaces/tests/external_grey_box_models.py b/pyomo/contrib/pynumero/interfaces/tests/external_grey_box_models.py
index e65e9a7eb5c..b81731b209e 100644
--- a/pyomo/contrib/pynumero/interfaces/tests/external_grey_box_models.py
+++ b/pyomo/contrib/pynumero/interfaces/tests/external_grey_box_models.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.contrib.pynumero.dependencies import (
     numpy as np,
     numpy_available,
diff --git a/pyomo/contrib/pynumero/interfaces/tests/test_cyipopt_interface.py b/pyomo/contrib/pynumero/interfaces/tests/test_cyipopt_interface.py
index f28b7b9b549..bbcd6d4f26d 100644
--- a/pyomo/contrib/pynumero/interfaces/tests/test_cyipopt_interface.py
+++ b/pyomo/contrib/pynumero/interfaces/tests/test_cyipopt_interface.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/interfaces/tests/test_dynamic_model.py b/pyomo/contrib/pynumero/interfaces/tests/test_dynamic_model.py
index ddd56afb5b4..5b8a8d688dd 100644
--- a/pyomo/contrib/pynumero/interfaces/tests/test_dynamic_model.py
+++ b/pyomo/contrib/pynumero/interfaces/tests/test_dynamic_model.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/interfaces/tests/test_external_asl_function.py b/pyomo/contrib/pynumero/interfaces/tests/test_external_asl_function.py
index 88a4024aeeb..9ca0aef4187 100644
--- a/pyomo/contrib/pynumero/interfaces/tests/test_external_asl_function.py
+++ b/pyomo/contrib/pynumero/interfaces/tests/test_external_asl_function.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/interfaces/tests/test_external_grey_box_model.py b/pyomo/contrib/pynumero/interfaces/tests/test_external_grey_box_model.py
index 58e08a409f0..0fc342c4e40 100644
--- a/pyomo/contrib/pynumero/interfaces/tests/test_external_grey_box_model.py
+++ b/pyomo/contrib/pynumero/interfaces/tests/test_external_grey_box_model.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/interfaces/tests/test_external_pyomo_block.py b/pyomo/contrib/pynumero/interfaces/tests/test_external_pyomo_block.py
index 7e250b9194e..913d3055c9c 100644
--- a/pyomo/contrib/pynumero/interfaces/tests/test_external_pyomo_block.py
+++ b/pyomo/contrib/pynumero/interfaces/tests/test_external_pyomo_block.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/interfaces/tests/test_external_pyomo_model.py b/pyomo/contrib/pynumero/interfaces/tests/test_external_pyomo_model.py
index 390d0b6fe63..9773fa7e4a8 100644
--- a/pyomo/contrib/pynumero/interfaces/tests/test_external_pyomo_model.py
+++ b/pyomo/contrib/pynumero/interfaces/tests/test_external_pyomo_model.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/interfaces/tests/test_nlp.py b/pyomo/contrib/pynumero/interfaces/tests/test_nlp.py
index 38d44473a67..4f735e06de7 100644
--- a/pyomo/contrib/pynumero/interfaces/tests/test_nlp.py
+++ b/pyomo/contrib/pynumero/interfaces/tests/test_nlp.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/interfaces/tests/test_nlp_projections.py b/pyomo/contrib/pynumero/interfaces/tests/test_nlp_projections.py
index 7bf693b1eb6..2fada5f679a 100644
--- a/pyomo/contrib/pynumero/interfaces/tests/test_nlp_projections.py
+++ b/pyomo/contrib/pynumero/interfaces/tests/test_nlp_projections.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/interfaces/tests/test_pyomo_grey_box_nlp.py b/pyomo/contrib/pynumero/interfaces/tests/test_pyomo_grey_box_nlp.py
index 52536dd9c06..ecadf40e5cf 100644
--- a/pyomo/contrib/pynumero/interfaces/tests/test_pyomo_grey_box_nlp.py
+++ b/pyomo/contrib/pynumero/interfaces/tests/test_pyomo_grey_box_nlp.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/interfaces/tests/test_utils.py b/pyomo/contrib/pynumero/interfaces/tests/test_utils.py
index dafe89ca2c7..474d26836b9 100644
--- a/pyomo/contrib/pynumero/interfaces/tests/test_utils.py
+++ b/pyomo/contrib/pynumero/interfaces/tests/test_utils.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/interfaces/utils.py b/pyomo/contrib/pynumero/interfaces/utils.py
index c7bd04eb002..2aa30fc5946 100644
--- a/pyomo/contrib/pynumero/interfaces/utils.py
+++ b/pyomo/contrib/pynumero/interfaces/utils.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/intrinsic.py b/pyomo/contrib/pynumero/intrinsic.py
index 5a2dccb64e7..34054e7ffa2 100644
--- a/pyomo/contrib/pynumero/intrinsic.py
+++ b/pyomo/contrib/pynumero/intrinsic.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -11,9 +11,7 @@
 
 from pyomo.common.dependencies import numpy as np, attempt_import
 
-block_vector = attempt_import(
-    'pyomo.contrib.pynumero.sparse.block_vector', defer_check=True
-)[0]
+block_vector = attempt_import('pyomo.contrib.pynumero.sparse.block_vector')[0]
 
 
 def norm(x, ord=None):
diff --git a/pyomo/contrib/pynumero/linalg/__init__.py b/pyomo/contrib/pynumero/linalg/__init__.py
index 09bccd7449b..c1d9ff38825 100644
--- a/pyomo/contrib/pynumero/linalg/__init__.py
+++ b/pyomo/contrib/pynumero/linalg/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/linalg/base.py b/pyomo/contrib/pynumero/linalg/base.py
index 2b4eeaef451..21565b052a5 100644
--- a/pyomo/contrib/pynumero/linalg/base.py
+++ b/pyomo/contrib/pynumero/linalg/base.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from abc import ABCMeta, abstractmethod
 import enum
 from typing import Optional, Union, Tuple
diff --git a/pyomo/contrib/pynumero/linalg/ma27.py b/pyomo/contrib/pynumero/linalg/ma27.py
index 21c137e837b..40a7d0e1064 100644
--- a/pyomo/contrib/pynumero/linalg/ma27.py
+++ b/pyomo/contrib/pynumero/linalg/ma27.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/linalg/ma27_interface.py b/pyomo/contrib/pynumero/linalg/ma27_interface.py
index 1ae02fe3290..42ac6e73154 100644
--- a/pyomo/contrib/pynumero/linalg/ma27_interface.py
+++ b/pyomo/contrib/pynumero/linalg/ma27_interface.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from .base import DirectLinearSolverInterface, LinearSolverStatus, LinearSolverResults
 from .ma27 import MA27Interface
 from scipy.sparse import isspmatrix_coo, tril, spmatrix
diff --git a/pyomo/contrib/pynumero/linalg/ma57.py b/pyomo/contrib/pynumero/linalg/ma57.py
index 1be6c8abcf7..baaa3f34100 100644
--- a/pyomo/contrib/pynumero/linalg/ma57.py
+++ b/pyomo/contrib/pynumero/linalg/ma57.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/linalg/ma57_interface.py b/pyomo/contrib/pynumero/linalg/ma57_interface.py
index ef80ac653cf..93004406612 100644
--- a/pyomo/contrib/pynumero/linalg/ma57_interface.py
+++ b/pyomo/contrib/pynumero/linalg/ma57_interface.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from .base import DirectLinearSolverInterface, LinearSolverStatus, LinearSolverResults
 from .ma57 import MA57Interface
 from scipy.sparse import isspmatrix_coo, tril, spmatrix
diff --git a/pyomo/contrib/pynumero/linalg/mumps_interface.py b/pyomo/contrib/pynumero/linalg/mumps_interface.py
index baab5562716..8735994f16c 100644
--- a/pyomo/contrib/pynumero/linalg/mumps_interface.py
+++ b/pyomo/contrib/pynumero/linalg/mumps_interface.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/linalg/scipy_interface.py b/pyomo/contrib/pynumero/linalg/scipy_interface.py
index 819e22ff1aa..025cc539245 100644
--- a/pyomo/contrib/pynumero/linalg/scipy_interface.py
+++ b/pyomo/contrib/pynumero/linalg/scipy_interface.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from .base import (
     DirectLinearSolverInterface,
     LinearSolverStatus,
diff --git a/pyomo/contrib/pynumero/linalg/tests/__init__.py b/pyomo/contrib/pynumero/linalg/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/pynumero/linalg/tests/__init__.py
+++ b/pyomo/contrib/pynumero/linalg/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/pynumero/linalg/tests/test_linear_solvers.py b/pyomo/contrib/pynumero/linalg/tests/test_linear_solvers.py
index 8d19127dde6..d2fa955434c 100644
--- a/pyomo/contrib/pynumero/linalg/tests/test_linear_solvers.py
+++ b/pyomo/contrib/pynumero/linalg/tests/test_linear_solvers.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.common import unittest
 from pyomo.contrib.pynumero.dependencies import numpy_available, scipy_available
 
diff --git a/pyomo/contrib/pynumero/linalg/tests/test_ma27.py b/pyomo/contrib/pynumero/linalg/tests/test_ma27.py
index 5a02871306a..979be6f747a 100644
--- a/pyomo/contrib/pynumero/linalg/tests/test_ma27.py
+++ b/pyomo/contrib/pynumero/linalg/tests/test_ma27.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/linalg/tests/test_ma57.py b/pyomo/contrib/pynumero/linalg/tests/test_ma57.py
index 86dbbd3ca50..de245172f96 100644
--- a/pyomo/contrib/pynumero/linalg/tests/test_ma57.py
+++ b/pyomo/contrib/pynumero/linalg/tests/test_ma57.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/linalg/tests/test_mumps_interface.py b/pyomo/contrib/pynumero/linalg/tests/test_mumps_interface.py
index 9b0aba96be1..8e5b924fb65 100644
--- a/pyomo/contrib/pynumero/linalg/tests/test_mumps_interface.py
+++ b/pyomo/contrib/pynumero/linalg/tests/test_mumps_interface.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/linalg/utils.py b/pyomo/contrib/pynumero/linalg/utils.py
index 2b7a9e99142..adec9ae5f35 100644
--- a/pyomo/contrib/pynumero/linalg/utils.py
+++ b/pyomo/contrib/pynumero/linalg/utils.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/plugins.py b/pyomo/contrib/pynumero/plugins.py
index 06bb0a5a059..c6890cbbb4d 100644
--- a/pyomo/contrib/pynumero/plugins.py
+++ b/pyomo/contrib/pynumero/plugins.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/sparse/__init__.py b/pyomo/contrib/pynumero/sparse/__init__.py
index e72d1cd7b2d..ee8196566db 100644
--- a/pyomo/contrib/pynumero/sparse/__init__.py
+++ b/pyomo/contrib/pynumero/sparse/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/sparse/base_block.py b/pyomo/contrib/pynumero/sparse/base_block.py
index 4f2ae385a7e..0b923ce6efb 100644
--- a/pyomo/contrib/pynumero/sparse/base_block.py
+++ b/pyomo/contrib/pynumero/sparse/base_block.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/sparse/block_matrix.py b/pyomo/contrib/pynumero/sparse/block_matrix.py
index 97e090fec4c..02ad584928b 100644
--- a/pyomo/contrib/pynumero/sparse/block_matrix.py
+++ b/pyomo/contrib/pynumero/sparse/block_matrix.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -31,8 +31,6 @@
 import logging
 import warnings
 
-__all__ = ['BlockMatrix', 'NotFullyDefinedBlockMatrixError']
-
 
 logger = logging.getLogger(__name__)
 
diff --git a/pyomo/contrib/pynumero/sparse/block_vector.py b/pyomo/contrib/pynumero/sparse/block_vector.py
index 00733a71752..b636dd74203 100644
--- a/pyomo/contrib/pynumero/sparse/block_vector.py
+++ b/pyomo/contrib/pynumero/sparse/block_vector.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -27,8 +27,6 @@
 from ..dependencies import numpy as np
 from .base_block import BaseBlockVector
 
-__all__ = ['BlockVector', 'NotFullyDefinedBlockVectorError']
-
 
 class NotFullyDefinedBlockVectorError(Exception):
     pass
diff --git a/pyomo/contrib/pynumero/sparse/mpi_block_matrix.py b/pyomo/contrib/pynumero/sparse/mpi_block_matrix.py
index ee045464dec..d32adebce0e 100644
--- a/pyomo/contrib/pynumero/sparse/mpi_block_matrix.py
+++ b/pyomo/contrib/pynumero/sparse/mpi_block_matrix.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -32,8 +32,6 @@
 from scipy.sparse import coo_matrix
 import operator
 
-__all__ = ['MPIBlockMatrix']
-
 
 def assert_block_structure(mat: MPIBlockMatrix):
     if mat.has_undefined_row_sizes() or mat.has_undefined_col_sizes():
diff --git a/pyomo/contrib/pynumero/sparse/mpi_block_vector.py b/pyomo/contrib/pynumero/sparse/mpi_block_vector.py
index 0f57f0eb41e..89cf136a5f7 100644
--- a/pyomo/contrib/pynumero/sparse/mpi_block_vector.py
+++ b/pyomo/contrib/pynumero/sparse/mpi_block_vector.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -17,8 +17,6 @@
 import numpy as np
 import operator
 
-__all__ = ['MPIBlockVector']
-
 
 def assert_block_structure(vec):
     if vec.has_none:
diff --git a/pyomo/contrib/pynumero/sparse/tests/__init__.py b/pyomo/contrib/pynumero/sparse/tests/__init__.py
index d93cfd77b3c..a4a626013c4 100644
--- a/pyomo/contrib/pynumero/sparse/tests/__init__.py
+++ b/pyomo/contrib/pynumero/sparse/tests/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/sparse/tests/test_block_matrix.py b/pyomo/contrib/pynumero/sparse/tests/test_block_matrix.py
index 7402881a285..48c1d3dc77e 100644
--- a/pyomo/contrib/pynumero/sparse/tests/test_block_matrix.py
+++ b/pyomo/contrib/pynumero/sparse/tests/test_block_matrix.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/sparse/tests/test_block_vector.py b/pyomo/contrib/pynumero/sparse/tests/test_block_vector.py
index 780a8bc2609..610d41a09a4 100644
--- a/pyomo/contrib/pynumero/sparse/tests/test_block_vector.py
+++ b/pyomo/contrib/pynumero/sparse/tests/test_block_vector.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/sparse/tests/test_intrinsics.py b/pyomo/contrib/pynumero/sparse/tests/test_intrinsics.py
index 0768442c2c4..ef0a5142849 100644
--- a/pyomo/contrib/pynumero/sparse/tests/test_intrinsics.py
+++ b/pyomo/contrib/pynumero/sparse/tests/test_intrinsics.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/sparse/tests/test_mpi_block_matrix.py b/pyomo/contrib/pynumero/sparse/tests/test_mpi_block_matrix.py
index 1415636c50d..917b4433120 100644
--- a/pyomo/contrib/pynumero/sparse/tests/test_mpi_block_matrix.py
+++ b/pyomo/contrib/pynumero/sparse/tests/test_mpi_block_matrix.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/sparse/tests/test_mpi_block_vector.py b/pyomo/contrib/pynumero/sparse/tests/test_mpi_block_vector.py
index cd37b7543a2..c28c524823a 100644
--- a/pyomo/contrib/pynumero/sparse/tests/test_mpi_block_vector.py
+++ b/pyomo/contrib/pynumero/sparse/tests/test_mpi_block_vector.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/src/AmplInterface.cpp b/pyomo/contrib/pynumero/src/AmplInterface.cpp
index 26053a9611b..805955f7671 100644
--- a/pyomo/contrib/pynumero/src/AmplInterface.cpp
+++ b/pyomo/contrib/pynumero/src/AmplInterface.cpp
@@ -1,7 +1,7 @@
 /**___________________________________________________________________________
  *
  * Pyomo: Python Optimization Modeling Objects
- * Copyright (c) 2008-2022
+ * Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
  * Under the terms of Contract DE-NA0003525 with National Technology and
  * Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/src/AmplInterface.hpp b/pyomo/contrib/pynumero/src/AmplInterface.hpp
index 259cf88d895..bedc6d4f669 100644
--- a/pyomo/contrib/pynumero/src/AmplInterface.hpp
+++ b/pyomo/contrib/pynumero/src/AmplInterface.hpp
@@ -1,7 +1,7 @@
 /**___________________________________________________________________________
  *
  * Pyomo: Python Optimization Modeling Objects
- * Copyright (c) 2008-2022
+ * Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
  * Under the terms of Contract DE-NA0003525 with National Technology and
  * Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/src/AssertUtils.hpp b/pyomo/contrib/pynumero/src/AssertUtils.hpp
index ba2e5dc887f..061442eb6e9 100644
--- a/pyomo/contrib/pynumero/src/AssertUtils.hpp
+++ b/pyomo/contrib/pynumero/src/AssertUtils.hpp
@@ -1,7 +1,7 @@
 /**___________________________________________________________________________
  *
  * Pyomo: Python Optimization Modeling Objects
- * Copyright (c) 2008-2022
+ * Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
  * Under the terms of Contract DE-NA0003525 with National Technology and
  * Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/pynumero/src/ma27Interface.cpp b/pyomo/contrib/pynumero/src/ma27Interface.cpp
index 624c7edd6f3..4816e1274e3 100644
--- a/pyomo/contrib/pynumero/src/ma27Interface.cpp
+++ b/pyomo/contrib/pynumero/src/ma27Interface.cpp
@@ -1,3 +1,15 @@
+/**___________________________________________________________________________
+ *
+ * Pyomo: Python Optimization Modeling Objects
+ * Copyright (c) 2008-2024
+ * National Technology and Engineering Solutions of Sandia, LLC
+ * Under the terms of Contract DE-NA0003525 with National Technology and
+ * Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+ * rights in this software.
+ * This software is distributed under the 3-clause BSD License.
+ * ___________________________________________________________________________
+**/
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdbool.h>
diff --git a/pyomo/contrib/pynumero/src/ma57Interface.cpp b/pyomo/contrib/pynumero/src/ma57Interface.cpp
index 99b98ef6215..fa9cf4e6811 100644
--- a/pyomo/contrib/pynumero/src/ma57Interface.cpp
+++ b/pyomo/contrib/pynumero/src/ma57Interface.cpp
@@ -1,3 +1,15 @@
+/**___________________________________________________________________________
+ *
+ * Pyomo: Python Optimization Modeling Objects
+ * Copyright (c) 2008-2024
+ * National Technology and Engineering Solutions of Sandia, LLC
+ * Under the terms of Contract DE-NA0003525 with National Technology and
+ * Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+ * rights in this software.
+ * This software is distributed under the 3-clause BSD License.
+ * ___________________________________________________________________________
+**/
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdbool.h>
diff --git a/pyomo/contrib/pynumero/src/tests/simple_test.cpp b/pyomo/contrib/pynumero/src/tests/simple_test.cpp
index 4edbbb67a35..9f39fbbd8ff 100644
--- a/pyomo/contrib/pynumero/src/tests/simple_test.cpp
+++ b/pyomo/contrib/pynumero/src/tests/simple_test.cpp
@@ -1,3 +1,15 @@
+/**___________________________________________________________________________
+ *
+ * Pyomo: Python Optimization Modeling Objects
+ * Copyright (c) 2008-2024
+ * National Technology and Engineering Solutions of Sandia, LLC
+ * Under the terms of Contract DE-NA0003525 with National Technology and
+ * Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+ * rights in this software.
+ * This software is distributed under the 3-clause BSD License.
+ * ___________________________________________________________________________
+**/
+
 #include<iostream>
 #include "AmplInterface.hpp"
 
diff --git a/pyomo/contrib/pynumero/tests/__init__.py b/pyomo/contrib/pynumero/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/pynumero/tests/__init__.py
+++ b/pyomo/contrib/pynumero/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/pyros/CHANGELOG.txt b/pyomo/contrib/pyros/CHANGELOG.txt
index 7d4678f0ba3..52cd7a6db47 100644
--- a/pyomo/contrib/pyros/CHANGELOG.txt
+++ b/pyomo/contrib/pyros/CHANGELOG.txt
@@ -2,6 +2,24 @@
 PyROS CHANGELOG
 ===============
 
+-------------------------------------------------------------------------------
+PyROS 1.2.11    17 Mar 2024
+-------------------------------------------------------------------------------
+- Standardize calls to subordinate solvers across all PyROS subproblem types
+- Account for user-specified subsolver time limits when automatically
+  adjusting subsolver time limits
+- Add support for automatic adjustment of SCIP subsolver time limit
+- Move start point of main PyROS solver timer to just before argument
+  validation begins
+
+
+-------------------------------------------------------------------------------
+PyROS 1.2.10    07 Feb 2024
+-------------------------------------------------------------------------------
+- Update argument resolution and validation routines of `PyROS.solve()`
+- Use methods of `common.config` for docstring of `PyROS.solve()`
+
+
 -------------------------------------------------------------------------------
 PyROS 1.2.9    15 Dec 2023
 -------------------------------------------------------------------------------
@@ -14,6 +32,7 @@ PyROS 1.2.9    15 Dec 2023
 - Refactor DR polishing routine; initialize auxiliary variables
   to values they are meant to represent
 
+
 -------------------------------------------------------------------------------
 PyROS 1.2.8    12 Oct 2023
 -------------------------------------------------------------------------------
diff --git a/pyomo/contrib/pyros/__init__.py b/pyomo/contrib/pyros/__init__.py
index aeb92eb13fd..4e134ef1166 100644
--- a/pyomo/contrib/pyros/__init__.py
+++ b/pyomo/contrib/pyros/__init__.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.contrib.pyros.pyros import PyROS
 from pyomo.contrib.pyros.pyros import ObjectiveType, pyrosTerminationCondition
 from pyomo.contrib.pyros.uncertainty_sets import (
diff --git a/pyomo/contrib/pyros/config.py b/pyomo/contrib/pyros/config.py
new file mode 100644
index 00000000000..c02dcd7ed0f
--- /dev/null
+++ b/pyomo/contrib/pyros/config.py
@@ -0,0 +1,879 @@
+"""
+Interfaces for managing PyROS solver options.
+"""
+
+from collections.abc import Iterable
+import logging
+
+from pyomo.common.collections import ComponentSet
+from pyomo.common.config import (
+    ConfigDict,
+    ConfigValue,
+    In,
+    IsInstance,
+    NonNegativeFloat,
+    InEnum,
+    Path,
+)
+from pyomo.common.errors import ApplicationError, PyomoException
+from pyomo.core.base import Var, VarData
+from pyomo.core.base.param import Param, ParamData
+from pyomo.opt import SolverFactory
+from pyomo.contrib.pyros.util import ObjectiveType, setup_pyros_logger
+from pyomo.contrib.pyros.uncertainty_sets import UncertaintySet
+
+
+default_pyros_solver_logger = setup_pyros_logger()
+
+
+def logger_domain(obj):
+    """
+    Domain validator for logger-type arguments.
+
+    This admits any object of type ``logging.Logger``,
+    or which can be cast to ``logging.Logger``.
+    """
+    if isinstance(obj, logging.Logger):
+        return obj
+    else:
+        return logging.getLogger(obj)
+
+
+logger_domain.domain_name = "None, str or logging.Logger"
+
+
+def positive_int_or_minus_one(obj):
+    """
+    Domain validator for objects castable to a strictly
+    positive int or -1.
+    """
+    ans = int(obj)
+    if ans != float(obj) or (ans <= 0 and ans != -1):
+        raise ValueError(f"Expected positive int or -1, but received value {obj!r}")
+    return ans
+
+
+positive_int_or_minus_one.domain_name = "positive int or -1"
+
+
+def mutable_param_validator(param_obj):
+    """
+    Check that Param-like object has attribute `mutable=True`.
+
+    Parameters
+    ----------
+    param_obj : Param or ParamData
+        Param-like object of interest.
+
+    Raises
+    ------
+    ValueError
+        If lengths of the param object and the accompanying
+        index set do not match. This may occur if some entry
+        of the Param is not initialized.
+    ValueError
+        If attribute `mutable` is of value False.
+    """
+    if len(param_obj) != len(param_obj.index_set()):
+        raise ValueError(
+            f"Length of Param component object with "
+            f"name {param_obj.name!r} is {len(param_obj)}, "
+            "and does not match that of its index set, "
+            f"which is of length {len(param_obj.index_set())}. "
+            "Check that all entries of the component object "
+            "have been initialized."
+        )
+    if not param_obj.mutable:
+        raise ValueError(f"Param object with name {param_obj.name!r} is immutable.")
+
+
+class InputDataStandardizer(object):
+    """
+    Standardizer for objects castable to a list of Pyomo
+    component types.
+
+    Parameters
+    ----------
+    ctype : type
+        Pyomo component type, such as Component, Var or Param.
+    cdatatype : type
+        Corresponding Pyomo component data type, such as
+        ComponentData, VarData, or ParamData.
+    ctype_validator : callable, optional
+        Validator function for objects of type `ctype`.
+    cdatatype_validator : callable, optional
+        Validator function for objects of type `cdatatype`.
+    allow_repeats : bool, optional
+        True to allow duplicate component data entries in final
+        list to which argument is cast, False otherwise.
+
+    Attributes
+    ----------
+    ctype
+    cdatatype
+    ctype_validator
+    cdatatype_validator
+    allow_repeats
+    """
+
+    def __init__(
+        self,
+        ctype,
+        cdatatype,
+        ctype_validator=None,
+        cdatatype_validator=None,
+        allow_repeats=False,
+    ):
+        """Initialize self (see class docstring)."""
+        self.ctype = ctype
+        self.cdatatype = cdatatype
+        self.ctype_validator = ctype_validator
+        self.cdatatype_validator = cdatatype_validator
+        self.allow_repeats = allow_repeats
+
+    def standardize_ctype_obj(self, obj):
+        """
+        Standardize object of type ``self.ctype`` to list
+        of objects of type ``self.cdatatype``.
+        """
+        if self.ctype_validator is not None:
+            self.ctype_validator(obj)
+        return list(obj.values())
+
+    def standardize_cdatatype_obj(self, obj):
+        """
+        Standardize object of type ``self.cdatatype`` to
+        ``[obj]``.
+        """
+        if self.cdatatype_validator is not None:
+            self.cdatatype_validator(obj)
+        return [obj]
+
+    def __call__(self, obj, from_iterable=None, allow_repeats=None):
+        """
+        Cast object to a flat list of Pyomo component data type
+        entries.
+
+        Parameters
+        ----------
+        obj : object
+            Object to be cast.
+        from_iterable : Iterable or None, optional
+            Iterable from which `obj` obtained, if any.
+        allow_repeats : bool or None, optional
+            True if list can contain repeated entries,
+            False otherwise.
+
+        Raises
+        ------
+        TypeError
+            If all entries in the resulting list
+            are not of type ``self.cdatatype``.
+        ValueError
+            If the resulting list contains duplicate entries.
+        """
+        if allow_repeats is None:
+            allow_repeats = self.allow_repeats
+
+        if isinstance(obj, self.ctype):
+            ans = self.standardize_ctype_obj(obj)
+        elif isinstance(obj, self.cdatatype):
+            ans = self.standardize_cdatatype_obj(obj)
+        elif isinstance(obj, Iterable) and not isinstance(obj, str):
+            ans = []
+            for item in obj:
+                ans.extend(self.__call__(item, from_iterable=obj))
+        else:
+            from_iterable_qual = (
+                f" (entry of iterable {from_iterable})"
+                if from_iterable is not None
+                else ""
+            )
+            raise TypeError(
+                f"Input object {obj!r}{from_iterable_qual} "
+                "is not of valid component type "
+                f"{self.ctype.__name__} or component data type "
+                f"{self.cdatatype.__name__}."
+            )
+
+        # check for duplicates if desired
+        if not allow_repeats and len(ans) != len(ComponentSet(ans)):
+            comp_name_list = [comp.name for comp in ans]
+            raise ValueError(
+                f"Standardized component list {comp_name_list} "
+                f"derived from input {obj} "
+                "contains duplicate entries."
+            )
+
+        return ans
+
+    def domain_name(self):
+        """Return str briefly describing domain encompassed by self."""
+        return (
+            f"{self.cdatatype.__name__}, {self.ctype.__name__}, "
+            f"or Iterable of {self.cdatatype.__name__}/{self.ctype.__name__}"
+        )
+
+
+class SolverNotResolvable(PyomoException):
+    """
+    Exception type for failure to cast an object to a Pyomo solver.
+    """
+
+
+class SolverResolvable(object):
+    """
+    Callable for casting an object (such as a str)
+    to a Pyomo solver.
+
+    Parameters
+    ----------
+    require_available : bool, optional
+        True if `available()` method of a standardized solver
+        object obtained through `self` must return `True`,
+        False otherwise.
+    solver_desc : str, optional
+        Descriptor for the solver obtained through `self`,
+        such as 'local solver'
+        or 'global solver'. This argument is used
+        for constructing error/exception messages.
+
+    Attributes
+    ----------
+    require_available
+    solver_desc
+    """
+
+    def __init__(self, require_available=True, solver_desc="solver"):
+        """Initialize self (see class docstring)."""
+        self.require_available = require_available
+        self.solver_desc = solver_desc
+
+    @staticmethod
+    def is_solver_type(obj):
+        """
+        Return True if object is considered a Pyomo solver,
+        False otherwise.
+
+        An object is considered a Pyomo solver provided that
+        it has callable attributes named 'solve' and
+        'available'.
+        """
+        return callable(getattr(obj, "solve", None)) and callable(
+            getattr(obj, "available", None)
+        )
+
+    def __call__(self, obj, require_available=None, solver_desc=None):
+        """
+        Cast object to a Pyomo solver.
+
+        If `obj` is a string, then ``SolverFactory(obj.lower())``
+        is returned. If `obj` is a Pyomo solver type, then
+        `obj` is returned.
+
+        Parameters
+        ----------
+        obj : object
+            Object to be cast to Pyomo solver type.
+        require_available : bool or None, optional
+            True if `available()` method of the resolved solver
+            object must return True, False otherwise.
+            If `None` is passed, then ``self.require_available``
+            is used.
+        solver_desc : str or None, optional
+            Brief description of the solver, such as 'local solver'
+            or 'backup global solver'. This argument is used
+            for constructing error/exception messages.
+            If `None` is passed, then ``self.solver_desc``
+            is used.
+
+        Returns
+        -------
+        Solver
+            Pyomo solver.
+
+        Raises
+        ------
+        SolverNotResolvable
+            If `obj` cannot be cast to a Pyomo solver because
+            it is neither a str nor a Pyomo solver type.
+        ApplicationError
+            In event that solver is not available, the
+            method `available(exception_flag=True)` of the
+            solver to which `obj` is cast should raise an
+            exception of this type. The present method
+            will also emit a more detailed error message
+            through the default PyROS logger.
+        """
+        # resort to defaults if necessary
+        if require_available is None:
+            require_available = self.require_available
+        if solver_desc is None:
+            solver_desc = self.solver_desc
+
+        # perform casting
+        if isinstance(obj, str):
+            solver = SolverFactory(obj.lower())
+        elif self.is_solver_type(obj):
+            solver = obj
+        else:
+            raise SolverNotResolvable(
+                f"Cannot cast object `{obj!r}` to a Pyomo optimizer for use as "
+                f"{solver_desc}, as the object is neither a str nor a "
+                f"Pyomo Solver type (got type {type(obj).__name__})."
+            )
+
+        # availability check, if so desired
+        if require_available:
+            try:
+                solver.available(exception_flag=True)
+            except ApplicationError:
+                default_pyros_solver_logger.exception(
+                    f"Output of `available()` method for {solver_desc} "
+                    f"with repr {solver!r} resolved from object {obj} "
+                    "is not `True`. "
+                    "Check solver and any required dependencies "
+                    "have been set up properly."
+                )
+                raise
+
+        return solver
+
+    def domain_name(self):
+        """Return str briefly describing domain encompassed by self."""
+        return "str or Solver"
+
+
+class SolverIterable(object):
+    """
+    Callable for casting an iterable (such as a list of strs)
+    to a list of Pyomo solvers.
+
+    Parameters
+    ----------
+    require_available : bool, optional
+        True if `available()` method of a standardized solver
+        object obtained through `self` must return `True`,
+        False otherwise.
+    filter_by_availability : bool, optional
+        True to remove standardized solvers for which `available()`
+        does not return True, False otherwise.
+    solver_desc : str, optional
+        Descriptor for the solver obtained through `self`,
+        such as 'backup local solver'
+        or 'backup global solver'.
+    """
+
+    def __init__(
+        self, require_available=True, filter_by_availability=True, solver_desc="solver"
+    ):
+        """Initialize self (see class docstring)."""
+        self.require_available = require_available
+        self.filter_by_availability = filter_by_availability
+        self.solver_desc = solver_desc
+
+    def __call__(
+        self, obj, require_available=None, filter_by_availability=None, solver_desc=None
+    ):
+        """
+        Cast iterable object to a list of Pyomo solver objects.
+
+        Parameters
+        ----------
+        obj : str, Solver, or Iterable of str/Solver
+            Object of interest.
+        require_available : bool or None, optional
+            True if `available()` method of each solver
+            object must return True, False otherwise.
+            If `None` is passed, then ``self.require_available``
+            is used.
+        solver_desc : str or None, optional
+            Descriptor for the solver, such as 'backup local solver'
+            or 'backup global solver'. This argument is used
+            for constructing error/exception messages.
+            If `None` is passed, then ``self.solver_desc``
+            is used.
+
+        Returns
+        -------
+        solvers : list of solver type
+            List of solver objects to which obj is cast.
+
+        Raises
+        ------
+        TypeError
+            If `obj` is a str.
+        """
+        if require_available is None:
+            require_available = self.require_available
+        if filter_by_availability is None:
+            filter_by_availability = self.filter_by_availability
+        if solver_desc is None:
+            solver_desc = self.solver_desc
+
+        solver_resolve_func = SolverResolvable()
+
+        if isinstance(obj, str) or solver_resolve_func.is_solver_type(obj):
+            # single solver resolvable is cast to singleton list.
+            # perform explicit check for str, otherwise this method
+            # would attempt to resolve each character.
+            obj_as_list = [obj]
+        else:
+            obj_as_list = list(obj)
+
+        solvers = []
+        for idx, val in enumerate(obj_as_list):
+            solver_desc_str = f"{solver_desc} " f"(index {idx})"
+            opt = solver_resolve_func(
+                obj=val,
+                require_available=require_available,
+                solver_desc=solver_desc_str,
+            )
+            if filter_by_availability and not opt.available(exception_flag=False):
+                default_pyros_solver_logger.warning(
+                    f"Output of `available()` method for solver object {opt} "
+                    f"resolved from object {val} of sequence {obj_as_list} "
+                    f"to be used as {self.solver_desc} "
+                    "is not `True`. "
+                    "Removing from list of standardized solvers."
+                )
+            else:
+                solvers.append(opt)
+
+        return solvers
+
+    def domain_name(self):
+        """Return str briefly describing domain encompassed by self."""
+        return "str, solver type, or Iterable of str/solver type"
+
+
+def pyros_config():
+    CONFIG = ConfigDict('PyROS')
+
+    # ================================================
+    # === Options common to all solvers
+    # ================================================
+    CONFIG.declare(
+        'time_limit',
+        ConfigValue(
+            default=None,
+            domain=NonNegativeFloat,
+            doc=(
+                """
+                Wall time limit for the execution of the PyROS solver
+                in seconds (including time spent by subsolvers).
+                If `None` is provided, then no time limit is enforced.
+                """
+            ),
+        ),
+    )
+    CONFIG.declare(
+        'keepfiles',
+        ConfigValue(
+            default=False,
+            domain=bool,
+            description=(
+                """
+                Export subproblems with a non-acceptable termination status
+                for debugging purposes.
+                If True is provided, then the argument
+                `subproblem_file_directory` must also be specified.
+                """
+            ),
+        ),
+    )
+    CONFIG.declare(
+        'tee',
+        ConfigValue(
+            default=False,
+            domain=bool,
+            description="Output subordinate solver logs for all subproblems.",
+        ),
+    )
+    CONFIG.declare(
+        'load_solution',
+        ConfigValue(
+            default=True,
+            domain=bool,
+            description=(
+                """
+                Load final solution(s) found by PyROS to the deterministic
+                model provided.
+                """
+            ),
+        ),
+    )
+    CONFIG.declare(
+        'symbolic_solver_labels',
+        ConfigValue(
+            default=False,
+            domain=bool,
+            description=(
+                """
+                True to ensure the component names given to the
+                subordinate solvers for every subproblem reflect
+                the names of the corresponding Pyomo modeling components,
+                False otherwise.
+                """
+            ),
+        ),
+    )
+
+    # ================================================
+    # === Required User Inputs
+    # ================================================
+    CONFIG.declare(
+        "first_stage_variables",
+        ConfigValue(
+            default=[],
+            domain=InputDataStandardizer(Var, VarData, allow_repeats=False),
+            description="First-stage (or design) variables.",
+            visibility=1,
+        ),
+    )
+    CONFIG.declare(
+        "second_stage_variables",
+        ConfigValue(
+            default=[],
+            domain=InputDataStandardizer(Var, VarData, allow_repeats=False),
+            description="Second-stage (or control) variables.",
+            visibility=1,
+        ),
+    )
+    CONFIG.declare(
+        "uncertain_params",
+        ConfigValue(
+            default=[],
+            domain=InputDataStandardizer(
+                ctype=Param,
+                cdatatype=ParamData,
+                ctype_validator=mutable_param_validator,
+                allow_repeats=False,
+            ),
+            description=(
+                """
+                Uncertain model parameters.
+                The `mutable` attribute for all uncertain parameter
+                objects should be set to True.
+                """
+            ),
+            visibility=1,
+        ),
+    )
+    CONFIG.declare(
+        "uncertainty_set",
+        ConfigValue(
+            default=None,
+            domain=IsInstance(UncertaintySet),
+            description=(
+                """
+                Uncertainty set against which the
+                final solution(s) returned by PyROS should be certified
+                to be robust.
+                """
+            ),
+            visibility=1,
+        ),
+    )
+    CONFIG.declare(
+        "local_solver",
+        ConfigValue(
+            default=None,
+            domain=SolverResolvable(solver_desc="local solver", require_available=True),
+            description="Subordinate local NLP solver.",
+            visibility=1,
+        ),
+    )
+    CONFIG.declare(
+        "global_solver",
+        ConfigValue(
+            default=None,
+            domain=SolverResolvable(
+                solver_desc="global solver", require_available=True
+            ),
+            description="Subordinate global NLP solver.",
+            visibility=1,
+        ),
+    )
+    # ================================================
+    # === Optional User Inputs
+    # ================================================
+    CONFIG.declare(
+        "objective_focus",
+        ConfigValue(
+            default=ObjectiveType.nominal,
+            domain=InEnum(ObjectiveType),
+            description=(
+                """
+                Choice of objective focus to optimize in the master problems.
+                Choices are: `ObjectiveType.worst_case`,
+                `ObjectiveType.nominal`.
+                """
+            ),
+            doc=(
+                """
+                Objective focus for the master problems:
+
+                - `ObjectiveType.nominal`:
+                  Optimize the objective function subject to the nominal
+                  uncertain parameter realization.
+                - `ObjectiveType.worst_case`:
+                  Optimize the objective function subject to the worst-case
+                  uncertain parameter realization.
+
+                By default, `ObjectiveType.nominal` is chosen.
+
+                A worst-case objective focus is required for certification
+                of robust optimality of the final solution(s) returned
+                by PyROS.
+                If a nominal objective focus is chosen, then only robust
+                feasibility is guaranteed.
+                """
+            ),
+        ),
+    )
+    CONFIG.declare(
+        "nominal_uncertain_param_vals",
+        ConfigValue(
+            default=[],
+            domain=list,
+            doc=(
+                """
+                Nominal uncertain parameter realization.
+                Entries should be provided in an order consistent with the
+                entries of the argument `uncertain_params`.
+                If an empty list is provided, then the values of the `Param`
+                objects specified through `uncertain_params` are chosen.
+                """
+            ),
+        ),
+    )
+    CONFIG.declare(
+        "decision_rule_order",
+        ConfigValue(
+            default=0,
+            domain=In([0, 1, 2]),
+            description=(
+                """
+                Order (or degree) of the polynomial decision rule functions
+                used for approximating the adjustability of the second stage
+                variables with respect to the uncertain parameters.
+                """
+            ),
+            doc=(
+                """
+                Order (or degree) of the polynomial decision rule functions
+                for approximating the adjustability of the second stage
+                variables with respect to the uncertain parameters.
+
+                Choices are:
+
+                - 0: static recourse
+                - 1: affine recourse
+                - 2: quadratic recourse
+                """
+            ),
+        ),
+    )
+    CONFIG.declare(
+        "solve_master_globally",
+        ConfigValue(
+            default=False,
+            domain=bool,
+            doc=(
+                """
+                True to solve all master problems with the subordinate
+                global solver, False to solve all master problems with
+                the subordinate local solver.
+                Along with a worst-case objective focus
+                (see argument `objective_focus`),
+                solving the master problems to global optimality is required
+                for certification
+                of robust optimality of the final solution(s) returned
+                by PyROS. Otherwise, only robust feasibility is guaranteed.
+                """
+            ),
+        ),
+    )
+    CONFIG.declare(
+        "max_iter",
+        ConfigValue(
+            default=-1,
+            domain=positive_int_or_minus_one,
+            description=(
+                """
+                Iteration limit. If -1 is provided, then no iteration
+                limit is enforced.
+                """
+            ),
+        ),
+    )
+    CONFIG.declare(
+        "robust_feasibility_tolerance",
+        ConfigValue(
+            default=1e-4,
+            domain=NonNegativeFloat,
+            description=(
+                """
+                Relative tolerance for assessing maximal inequality
+                constraint violations during the GRCS separation step.
+                """
+            ),
+        ),
+    )
+    CONFIG.declare(
+        "separation_priority_order",
+        ConfigValue(
+            default={},
+            domain=dict,
+            doc=(
+                """
+                Mapping from model inequality constraint names
+                to positive integers specifying the priorities
+                of their corresponding separation subproblems.
+                A higher integer value indicates a higher priority.
+                Constraints not referenced in the `dict` assume
+                a priority of 0.
+                Separation subproblems are solved in order of decreasing
+                priority.
+                """
+            ),
+        ),
+    )
+    CONFIG.declare(
+        "progress_logger",
+        ConfigValue(
+            default=default_pyros_solver_logger,
+            domain=logger_domain,
+            doc=(
+                """
+                Logger (or name thereof) used for reporting PyROS solver
+                progress. If `None` or a `str` is provided, then
+                ``progress_logger``
+                is cast to ``logging.getLogger(progress_logger)``.
+                In the default case, `progress_logger` is set to
+                a :class:`pyomo.contrib.pyros.util.PreformattedLogger`
+                object of level ``logging.INFO``.
+                """
+            ),
+        ),
+    )
+    CONFIG.declare(
+        "backup_local_solvers",
+        ConfigValue(
+            default=[],
+            domain=SolverIterable(
+                solver_desc="backup local solver",
+                require_available=False,
+                filter_by_availability=True,
+            ),
+            doc=(
+                """
+                Additional subordinate local NLP optimizers to invoke
+                in the event the primary local NLP optimizer fails
+                to solve a subproblem to an acceptable termination condition.
+                """
+            ),
+        ),
+    )
+    CONFIG.declare(
+        "backup_global_solvers",
+        ConfigValue(
+            default=[],
+            domain=SolverIterable(
+                solver_desc="backup global solver",
+                require_available=False,
+                filter_by_availability=True,
+            ),
+            doc=(
+                """
+                Additional subordinate global NLP optimizers to invoke
+                in the event the primary global NLP optimizer fails
+                to solve a subproblem to an acceptable termination condition.
+                """
+            ),
+        ),
+    )
+    CONFIG.declare(
+        "subproblem_file_directory",
+        ConfigValue(
+            default=None,
+            domain=Path(),
+            description=(
+                """
+                Directory to which to export subproblems not successfully
+                solved to an acceptable termination condition.
+                In the event ``keepfiles=True`` is specified, a str or
+                path-like referring to an existing directory must be
+                provided.
+                """
+            ),
+        ),
+    )
+
+    # ================================================
+    # === Advanced Options
+    # ================================================
+    CONFIG.declare(
+        "bypass_local_separation",
+        ConfigValue(
+            default=False,
+            domain=bool,
+            description=(
+                """
+                This is an advanced option.
+                Solve all separation subproblems with the subordinate global
+                solver(s) only.
+                This option is useful for expediting PyROS
+                in the event that the subordinate global optimizer(s) provided
+                can quickly solve separation subproblems to global optimality.
+                """
+            ),
+        ),
+    )
+    CONFIG.declare(
+        "bypass_global_separation",
+        ConfigValue(
+            default=False,
+            domain=bool,
+            doc=(
+                """
+                This is an advanced option.
+                Solve all separation subproblems with the subordinate local
+                solver(s) only.
+                If `True` is chosen, then robustness of the final solution(s)
+                returned by PyROS is not guaranteed, and a warning will
+                be issued at termination.
+                This option is useful for expediting PyROS
+                in the event that the subordinate global optimizer provided
+                cannot tractably solve separation subproblems to global
+                optimality.
+                """
+            ),
+        ),
+    )
+    CONFIG.declare(
+        "p_robustness",
+        ConfigValue(
+            default={},
+            domain=dict,
+            doc=(
+                """
+                This is an advanced option.
+                Add p-robustness constraints to all master subproblems.
+                If an empty dict is provided, then p-robustness constraints
+                are not added.
+                Otherwise, the dict must map a `str` of value ``'rho'``
+                to a non-negative `float`. PyROS automatically
+                specifies ``1 + p_robustness['rho']``
+                as an upper bound for the ratio of the
+                objective function value under any PyROS-sampled uncertain
+                parameter realization to the objective function under
+                the nominal parameter realization.
+                """
+            ),
+            visibility=1,
+        ),
+    )
+
+    return CONFIG
diff --git a/pyomo/contrib/pyros/master_problem_methods.py b/pyomo/contrib/pyros/master_problem_methods.py
index e2ce74a493e..2af38c1d582 100644
--- a/pyomo/contrib/pyros/master_problem_methods.py
+++ b/pyomo/contrib/pyros/master_problem_methods.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """
 Functions for handling the construction and solving of the GRCS master problem via ROSolver
 """
@@ -16,6 +27,7 @@
 from pyomo.core.expr import value
 from pyomo.core.base.set_types import NonNegativeIntegers, NonNegativeReals
 from pyomo.contrib.pyros.util import (
+    call_solver,
     selective_clone,
     ObjectiveType,
     pyrosTerminationCondition,
@@ -228,31 +240,18 @@ def solve_master_feasibility_problem(model_data, config):
     else:
         solver = config.local_solver
 
-    timer = TicTocTimer()
-    orig_setting, custom_setting_present = adjust_solver_time_settings(
-        model_data.timing, solver, config
-    )
-    model_data.timing.start_timer("main.master_feasibility")
-    timer.tic(msg=None)
-    try:
-        results = solver.solve(model, tee=config.tee, load_solutions=False)
-    except ApplicationError:
-        # account for possible external subsolver errors
-        # (such as segmentation faults, function evaluation
-        # errors, etc.)
-        config.progress_logger.error(
+    results = call_solver(
+        model=model,
+        solver=solver,
+        config=config,
+        timing_obj=model_data.timing,
+        timer_name="main.master_feasibility",
+        err_msg=(
             f"Optimizer {repr(solver)} encountered exception "
             "attempting to solve master feasibility problem in iteration "
             f"{model_data.iteration}."
-        )
-        raise
-    else:
-        setattr(results.solver, TIC_TOC_SOLVE_TIME_ATTR, timer.toc(msg=None))
-        model_data.timing.stop_timer("main.master_feasibility")
-    finally:
-        revert_solver_max_time_adjustment(
-            solver, orig_setting, custom_setting_present, config
-        )
+        ),
+    )
 
     feasible_terminations = {
         tc.optimal,
@@ -387,10 +386,17 @@ def construct_dr_polishing_problem(model_data, config):
         all_ub_cons.append(polishing_absolute_value_ub_cons)
 
         # get monomials; ensure second-stage variable term excluded
+        #
+        # the dr_eq is a linear sum where the first term is the
+        # second-stage variable: the remainder of the terms will be
+        # either MonomialTermExpressions or bare VarData
         dr_expr_terms = dr_eq.body.args[:-1]
 
         for dr_eq_term in dr_expr_terms:
-            dr_var_in_term = dr_eq_term.args[-1]
+            if dr_eq_term.is_expression_type():
+                dr_var_in_term = dr_eq_term.args[-1]
+            else:
+                dr_var_in_term = dr_eq_term
             dr_var_in_term_idx = dr_var_in_term.index()
 
             # get corresponding polishing variable
@@ -464,28 +470,18 @@ def minimize_dr_vars(model_data, config):
     config.progress_logger.debug(f" Initial DR norm: {value(polishing_obj)}")
 
     # === Solve the polishing model
-    timer = TicTocTimer()
-    orig_setting, custom_setting_present = adjust_solver_time_settings(
-        model_data.timing, solver, config
-    )
-    model_data.timing.start_timer("main.dr_polishing")
-    timer.tic(msg=None)
-    try:
-        results = solver.solve(polishing_model, tee=config.tee, load_solutions=False)
-    except ApplicationError:
-        config.progress_logger.error(
+    results = call_solver(
+        model=polishing_model,
+        solver=solver,
+        config=config,
+        timing_obj=model_data.timing,
+        timer_name="main.dr_polishing",
+        err_msg=(
             f"Optimizer {repr(solver)} encountered an exception "
             "attempting to solve decision rule polishing problem "
             f"in iteration {model_data.iteration}"
-        )
-        raise
-    else:
-        setattr(results.solver, TIC_TOC_SOLVE_TIME_ATTR, timer.toc(msg=None))
-        model_data.timing.stop_timer("main.dr_polishing")
-    finally:
-        revert_solver_max_time_adjustment(
-            solver, orig_setting, custom_setting_present, config
-        )
+        ),
+    )
 
     # interested in the time and termination status for debugging
     # purposes
@@ -708,7 +704,6 @@ def solver_call_master(model_data, config, solver, solve_data):
     solve_mode = "global" if config.solve_master_globally else "local"
     config.progress_logger.debug("Solving master problem")
 
-    timer = TicTocTimer()
     for idx, opt in enumerate(solvers):
         if idx > 0:
             config.progress_logger.warning(
@@ -716,35 +711,18 @@ def solver_call_master(model_data, config, solver, solve_data):
                 f"(solver {idx + 1} of {len(solvers)}) for "
                 f"master problem of iteration {model_data.iteration}."
             )
-        orig_setting, custom_setting_present = adjust_solver_time_settings(
-            model_data.timing, opt, config
-        )
-        model_data.timing.start_timer("main.master")
-        timer.tic(msg=None)
-        try:
-            results = opt.solve(
-                nlp_model,
-                tee=config.tee,
-                load_solutions=False,
-                symbolic_solver_labels=True,
-            )
-        except ApplicationError:
-            # account for possible external subsolver errors
-            # (such as segmentation faults, function evaluation
-            # errors, etc.)
-            config.progress_logger.error(
+        results = call_solver(
+            model=nlp_model,
+            solver=opt,
+            config=config,
+            timing_obj=model_data.timing,
+            timer_name="main.master",
+            err_msg=(
                 f"Optimizer {repr(opt)} ({idx + 1} of {len(solvers)}) "
                 "encountered exception attempting to "
                 f"solve master problem in iteration {model_data.iteration}"
-            )
-            raise
-        else:
-            setattr(results.solver, TIC_TOC_SOLVE_TIME_ATTR, timer.toc(msg=None))
-            model_data.timing.stop_timer("main.master")
-        finally:
-            revert_solver_max_time_adjustment(
-                solver, orig_setting, custom_setting_present, config
-            )
+            ),
+        )
 
         optimal_termination = check_optimal_termination(results)
         infeasible = results.solver.termination_condition == tc.infeasible
diff --git a/pyomo/contrib/pyros/pyros.py b/pyomo/contrib/pyros/pyros.py
index 829184fc70c..582233c4a56 100644
--- a/pyomo/contrib/pyros/pyros.py
+++ b/pyomo/contrib/pyros/pyros.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -11,29 +11,24 @@
 
 # pyros.py: Generalized Robust Cutting-Set Algorithm for Pyomo
 import logging
-from textwrap import indent, dedent, wrap
-from pyomo.common.collections import Bunch, ComponentSet
-from pyomo.common.config import ConfigDict, ConfigValue, In, NonNegativeFloat
+from pyomo.common.config import document_kwargs_from_configdict
 from pyomo.core.base.block import Block
 from pyomo.core.expr import value
-from pyomo.core.base.var import Var, _VarData
-from pyomo.core.base.param import Param, _ParamData
-from pyomo.core.base.objective import Objective, maximize
-from pyomo.contrib.pyros.util import a_logger, time_code, get_main_elapsed_time
+from pyomo.core.base.var import Var
+from pyomo.core.base.objective import Objective
+from pyomo.contrib.pyros.util import time_code
 from pyomo.common.modeling import unique_component_name
 from pyomo.opt import SolverFactory
+from pyomo.contrib.pyros.config import pyros_config, logger_domain
 from pyomo.contrib.pyros.util import (
-    model_is_valid,
     recast_to_min_obj,
     add_decision_rule_constraints,
     add_decision_rule_variables,
     load_final_solution,
     pyrosTerminationCondition,
-    ValidEnum,
     ObjectiveType,
-    validate_uncertainty_set,
     identify_objective_functions,
-    validate_kwarg_inputs,
+    validate_pyros_inputs,
     transform_to_standard_form,
     turn_bounds_to_constraints,
     replace_uncertain_bounds_with_constraints,
@@ -43,13 +38,12 @@
 )
 from pyomo.contrib.pyros.solve_data import ROSolveResults
 from pyomo.contrib.pyros.pyros_algorithm_methods import ROSolver_iterative_solve
-from pyomo.contrib.pyros.uncertainty_sets import uncertainty_sets
 from pyomo.core.base import Constraint
 
 from datetime import datetime
 
 
-__version__ = "1.2.9"
+__version__ = "1.2.11"
 
 
 default_pyros_solver_logger = setup_pyros_logger()
@@ -85,590 +79,6 @@ def _get_pyomo_version_info():
     return {"Pyomo version": pyomo_version, "Commit hash": commit_hash}
 
 
-def NonNegIntOrMinusOne(obj):
-    '''
-    if obj is a non-negative int, return the non-negative int
-    if obj is -1, return -1
-    else, error
-    '''
-    ans = int(obj)
-    if ans != float(obj) or (ans < 0 and ans != -1):
-        raise ValueError("Expected non-negative int, but received %s" % (obj,))
-    return ans
-
-
-def PositiveIntOrMinusOne(obj):
-    '''
-    if obj is a positive int, return the int
-    if obj is -1, return -1
-    else, error
-    '''
-    ans = int(obj)
-    if ans != float(obj) or (ans <= 0 and ans != -1):
-        raise ValueError("Expected positive int, but received %s" % (obj,))
-    return ans
-
-
-class SolverResolvable(object):
-    def __call__(self, obj):
-        '''
-        if obj is a string, return the Solver object for that solver name
-        if obj is a Solver object, return a copy of the Solver
-        if obj is a list, and each element of list is solver resolvable, return list of solvers
-        '''
-        if isinstance(obj, str):
-            return SolverFactory(obj.lower())
-        elif callable(getattr(obj, "solve", None)):
-            return obj
-        elif isinstance(obj, list):
-            return [self(o) for o in obj]
-        else:
-            raise ValueError(
-                "Expected a Pyomo solver or string object, "
-                "instead received {1}".format(obj.__class__.__name__)
-            )
-
-
-class InputDataStandardizer(object):
-    def __init__(self, ctype, cdatatype):
-        self.ctype = ctype
-        self.cdatatype = cdatatype
-
-    def __call__(self, obj):
-        if isinstance(obj, self.ctype):
-            return list(obj.values())
-        if isinstance(obj, self.cdatatype):
-            return [obj]
-        ans = []
-        for item in obj:
-            ans.extend(self.__call__(item))
-        for _ in ans:
-            assert isinstance(_, self.cdatatype)
-        return ans
-
-
-class PyROSConfigValue(ConfigValue):
-    """
-    Subclass of ``common.collections.ConfigValue``,
-    with a few attributes added to facilitate documentation
-    of the PyROS solver.
-    An instance of this class is used for storing and
-    documenting an argument to the PyROS solver.
-
-    Attributes
-    ----------
-    is_optional : bool
-        Argument is optional.
-    document_default : bool, optional
-        Document the default value of the argument
-        in any docstring generated from this instance,
-        or a `ConfigDict` object containing this instance.
-    dtype_spec_str : None or str, optional
-        String documenting valid types for this argument.
-        If `None` is provided, then this string is automatically
-        determined based on the `domain` argument to the
-        constructor.
-
-    NOTES
-    -----
-    Cleaner way to access protected attributes
-    (particularly _doc, _description) inherited from ConfigValue?
-
-    """
-
-    def __init__(
-        self,
-        default=None,
-        domain=None,
-        description=None,
-        doc=None,
-        visibility=0,
-        is_optional=True,
-        document_default=True,
-        dtype_spec_str=None,
-    ):
-        """Initialize self (see class docstring)."""
-
-        # initialize base class attributes
-        super(self.__class__, self).__init__(
-            default=default,
-            domain=domain,
-            description=description,
-            doc=doc,
-            visibility=visibility,
-        )
-
-        self.is_optional = is_optional
-        self.document_default = document_default
-
-        if dtype_spec_str is None:
-            self.dtype_spec_str = self.domain_name()
-            # except AttributeError:
-            #     self.dtype_spec_str = repr(self._domain)
-        else:
-            self.dtype_spec_str = dtype_spec_str
-
-
-def pyros_config():
-    CONFIG = ConfigDict('PyROS')
-
-    # ================================================
-    # === Options common to all solvers
-    # ================================================
-    CONFIG.declare(
-        'time_limit',
-        PyROSConfigValue(
-            default=None,
-            domain=NonNegativeFloat,
-            doc=(
-                """
-                Wall time limit for the execution of the PyROS solver
-                in seconds (including time spent by subsolvers).
-                If `None` is provided, then no time limit is enforced.
-                """
-            ),
-            is_optional=True,
-            document_default=False,
-            dtype_spec_str="None or NonNegativeFloat",
-        ),
-    )
-    CONFIG.declare(
-        'keepfiles',
-        PyROSConfigValue(
-            default=False,
-            domain=bool,
-            description=(
-                """
-                Export subproblems with a non-acceptable termination status
-                for debugging purposes.
-                If True is provided, then the argument `subproblem_file_directory`
-                must also be specified.
-                """
-            ),
-            is_optional=True,
-            document_default=True,
-            dtype_spec_str=None,
-        ),
-    )
-    CONFIG.declare(
-        'tee',
-        PyROSConfigValue(
-            default=False,
-            domain=bool,
-            description="Output subordinate solver logs for all subproblems.",
-            is_optional=True,
-            document_default=True,
-            dtype_spec_str=None,
-        ),
-    )
-    CONFIG.declare(
-        'load_solution',
-        PyROSConfigValue(
-            default=True,
-            domain=bool,
-            description=(
-                """
-                Load final solution(s) found by PyROS to the deterministic model
-                provided.
-                """
-            ),
-            is_optional=True,
-            document_default=True,
-            dtype_spec_str=None,
-        ),
-    )
-
-    # ================================================
-    # === Required User Inputs
-    # ================================================
-    CONFIG.declare(
-        "first_stage_variables",
-        PyROSConfigValue(
-            default=[],
-            domain=InputDataStandardizer(Var, _VarData),
-            description="First-stage (or design) variables.",
-            is_optional=False,
-            dtype_spec_str="list of Var",
-        ),
-    )
-    CONFIG.declare(
-        "second_stage_variables",
-        PyROSConfigValue(
-            default=[],
-            domain=InputDataStandardizer(Var, _VarData),
-            description="Second-stage (or control) variables.",
-            is_optional=False,
-            dtype_spec_str="list of Var",
-        ),
-    )
-    CONFIG.declare(
-        "uncertain_params",
-        PyROSConfigValue(
-            default=[],
-            domain=InputDataStandardizer(Param, _ParamData),
-            description=(
-                """
-                Uncertain model parameters.
-                The `mutable` attribute for all uncertain parameter
-                objects should be set to True.
-                """
-            ),
-            is_optional=False,
-            dtype_spec_str="list of Param",
-        ),
-    )
-    CONFIG.declare(
-        "uncertainty_set",
-        PyROSConfigValue(
-            default=None,
-            domain=uncertainty_sets,
-            description=(
-                """
-                Uncertainty set against which the
-                final solution(s) returned by PyROS should be certified
-                to be robust.
-                """
-            ),
-            is_optional=False,
-            dtype_spec_str="UncertaintySet",
-        ),
-    )
-    CONFIG.declare(
-        "local_solver",
-        PyROSConfigValue(
-            default=None,
-            domain=SolverResolvable(),
-            description="Subordinate local NLP solver.",
-            is_optional=False,
-            dtype_spec_str="Solver",
-        ),
-    )
-    CONFIG.declare(
-        "global_solver",
-        PyROSConfigValue(
-            default=None,
-            domain=SolverResolvable(),
-            description="Subordinate global NLP solver.",
-            is_optional=False,
-            dtype_spec_str="Solver",
-        ),
-    )
-    # ================================================
-    # === Optional User Inputs
-    # ================================================
-    CONFIG.declare(
-        "objective_focus",
-        PyROSConfigValue(
-            default=ObjectiveType.nominal,
-            domain=ValidEnum(ObjectiveType),
-            description=(
-                """
-                Choice of objective focus to optimize in the master problems.
-                Choices are: `ObjectiveType.worst_case`,
-                `ObjectiveType.nominal`.
-                """
-            ),
-            doc=(
-                """
-                Objective focus for the master problems:
-    
-                - `ObjectiveType.nominal`:
-                  Optimize the objective function subject to the nominal
-                  uncertain parameter realization.
-                - `ObjectiveType.worst_case`:
-                  Optimize the objective function subject to the worst-case
-                  uncertain parameter realization.
-    
-                By default, `ObjectiveType.nominal` is chosen.
-    
-                A worst-case objective focus is required for certification
-                of robust optimality of the final solution(s) returned
-                by PyROS.
-                If a nominal objective focus is chosen, then only robust
-                feasibility is guaranteed.
-                """
-            ),
-            is_optional=True,
-            document_default=False,
-            dtype_spec_str="ObjectiveType",
-        ),
-    )
-    CONFIG.declare(
-        "nominal_uncertain_param_vals",
-        PyROSConfigValue(
-            default=[],
-            domain=list,
-            doc=(
-                """
-                Nominal uncertain parameter realization.
-                Entries should be provided in an order consistent with the
-                entries of the argument `uncertain_params`.
-                If an empty list is provided, then the values of the `Param`
-                objects specified through `uncertain_params` are chosen.
-                """
-            ),
-            is_optional=True,
-            document_default=True,
-            dtype_spec_str="list of float",
-        ),
-    )
-    CONFIG.declare(
-        "decision_rule_order",
-        PyROSConfigValue(
-            default=0,
-            domain=In([0, 1, 2]),
-            description=(
-                """
-                Order (or degree) of the polynomial decision rule functions used
-                for approximating the adjustability of the second stage
-                variables with respect to the uncertain parameters.
-                """
-            ),
-            doc=(
-                """
-                Order (or degree) of the polynomial decision rule functions used
-                for approximating the adjustability of the second stage
-                variables with respect to the uncertain parameters.
-    
-                Choices are:
-    
-                - 0: static recourse
-                - 1: affine recourse
-                - 2: quadratic recourse
-                """
-            ),
-            is_optional=True,
-            document_default=True,
-            dtype_spec_str=None,
-        ),
-    )
-    CONFIG.declare(
-        "solve_master_globally",
-        PyROSConfigValue(
-            default=False,
-            domain=bool,
-            doc=(
-                """
-                True to solve all master problems with the subordinate
-                global solver, False to solve all master problems with
-                the subordinate local solver.
-                Along with a worst-case objective focus
-                (see argument `objective_focus`),
-                solving the master problems to global optimality is required
-                for certification
-                of robust optimality of the final solution(s) returned
-                by PyROS. Otherwise, only robust feasibility is guaranteed.
-                """
-            ),
-            is_optional=True,
-            document_default=True,
-            dtype_spec_str=None,
-        ),
-    )
-    CONFIG.declare(
-        "max_iter",
-        PyROSConfigValue(
-            default=-1,
-            domain=PositiveIntOrMinusOne,
-            description=(
-                """
-                Iteration limit. If -1 is provided, then no iteration
-                limit is enforced.
-                """
-            ),
-            is_optional=True,
-            document_default=True,
-            dtype_spec_str="int",
-        ),
-    )
-    CONFIG.declare(
-        "robust_feasibility_tolerance",
-        PyROSConfigValue(
-            default=1e-4,
-            domain=NonNegativeFloat,
-            description=(
-                """
-                Relative tolerance for assessing maximal inequality
-                constraint violations during the GRCS separation step.
-                """
-            ),
-            is_optional=True,
-            document_default=True,
-            dtype_spec_str=None,
-        ),
-    )
-    CONFIG.declare(
-        "separation_priority_order",
-        PyROSConfigValue(
-            default={},
-            domain=dict,
-            doc=(
-                """
-                Mapping from model inequality constraint names
-                to positive integers specifying the priorities
-                of their corresponding separation subproblems.
-                A higher integer value indicates a higher priority.
-                Constraints not referenced in the `dict` assume
-                a priority of 0.
-                Separation subproblems are solved in order of decreasing
-                priority.
-                """
-            ),
-            is_optional=True,
-            document_default=True,
-            dtype_spec_str=None,
-        ),
-    )
-    CONFIG.declare(
-        "progress_logger",
-        PyROSConfigValue(
-            default=default_pyros_solver_logger,
-            domain=a_logger,
-            doc=(
-                """
-                Logger (or name thereof) used for reporting PyROS solver
-                progress. If a `str` is specified, then ``progress_logger``
-                is cast to ``logging.getLogger(progress_logger)``.
-                In the default case, `progress_logger` is set to
-                a :class:`pyomo.contrib.pyros.util.PreformattedLogger`
-                object of level ``logging.INFO``.
-                """
-            ),
-            is_optional=True,
-            document_default=True,
-            dtype_spec_str="str or logging.Logger",
-        ),
-    )
-    CONFIG.declare(
-        "backup_local_solvers",
-        PyROSConfigValue(
-            default=[],
-            domain=SolverResolvable(),
-            doc=(
-                """
-                Additional subordinate local NLP optimizers to invoke
-                in the event the primary local NLP optimizer fails
-                to solve a subproblem to an acceptable termination condition.
-                """
-            ),
-            is_optional=True,
-            document_default=True,
-            dtype_spec_str="list of Solver",
-        ),
-    )
-    CONFIG.declare(
-        "backup_global_solvers",
-        PyROSConfigValue(
-            default=[],
-            domain=SolverResolvable(),
-            doc=(
-                """
-                Additional subordinate global NLP optimizers to invoke
-                in the event the primary global NLP optimizer fails
-                to solve a subproblem to an acceptable termination condition.
-                """
-            ),
-            is_optional=True,
-            document_default=True,
-            dtype_spec_str="list of Solver",
-        ),
-    )
-    CONFIG.declare(
-        "subproblem_file_directory",
-        PyROSConfigValue(
-            default=None,
-            domain=str,
-            description=(
-                """
-                Directory to which to export subproblems not successfully
-                solved to an acceptable termination condition.
-                In the event ``keepfiles=True`` is specified, a str or
-                path-like referring to an existing directory must be
-                provided.
-                """
-            ),
-            is_optional=True,
-            document_default=True,
-            dtype_spec_str="None, str, or path-like",
-        ),
-    )
-
-    # ================================================
-    # === Advanced Options
-    # ================================================
-    CONFIG.declare(
-        "bypass_local_separation",
-        PyROSConfigValue(
-            default=False,
-            domain=bool,
-            description=(
-                """
-                This is an advanced option.
-                Solve all separation subproblems with the subordinate global
-                solver(s) only.
-                This option is useful for expediting PyROS
-                in the event that the subordinate global optimizer(s) provided
-                can quickly solve separation subproblems to global optimality.
-                """
-            ),
-            is_optional=True,
-            document_default=True,
-            dtype_spec_str=None,
-        ),
-    )
-    CONFIG.declare(
-        "bypass_global_separation",
-        PyROSConfigValue(
-            default=False,
-            domain=bool,
-            doc=(
-                """
-                This is an advanced option.
-                Solve all separation subproblems with the subordinate local
-                solver(s) only.
-                If `True` is chosen, then robustness of the final solution(s)
-                returned by PyROS is not guaranteed, and a warning will
-                be issued at termination.
-                This option is useful for expediting PyROS
-                in the event that the subordinate global optimizer provided
-                cannot tractably solve separation subproblems to global
-                optimality.
-                """
-            ),
-            is_optional=True,
-            document_default=True,
-            dtype_spec_str=None,
-        ),
-    )
-    CONFIG.declare(
-        "p_robustness",
-        PyROSConfigValue(
-            default={},
-            domain=dict,
-            doc=(
-                """
-                This is an advanced option.
-                Add p-robustness constraints to all master subproblems.
-                If an empty dict is provided, then p-robustness constraints
-                are not added.
-                Otherwise, the dict must map a `str` of value ``'rho'``
-                to a non-negative `float`. PyROS automatically
-                specifies ``1 + p_robustness['rho']``
-                as an upper bound for the ratio of the
-                objective function value under any PyROS-sampled uncertain
-                parameter realization to the objective function under
-                the nominal parameter realization.
-                """
-            ),
-            is_optional=True,
-            document_default=True,
-            dtype_spec_str=None,
-        ),
-    )
-
-    return CONFIG
-
-
 @SolverFactory.register(
     "pyros",
     doc="Robust optimization (RO) solver implementing "
@@ -836,6 +246,46 @@ def _log_config(self, logger, config, exclude_options=None, **log_kwargs):
                 logger.log(msg=f" {key}={val!r}", **log_kwargs)
         logger.log(msg="-" * self._LOG_LINE_LENGTH, **log_kwargs)
 
+    def _resolve_and_validate_pyros_args(self, model, **kwds):
+        """
+        Resolve and validate arguments to ``self.solve()``.
+
+        Parameters
+        ----------
+        model : ConcreteModel
+            Deterministic model object passed to ``self.solve()``.
+        **kwds : dict
+            All other arguments to ``self.solve()``.
+
+        Returns
+        -------
+        config : ConfigDict
+            Standardized arguments.
+
+        Note
+        ----
+        This method can be broken down into three steps:
+
+        1. Cast arguments to ConfigDict. Argument-wise
+           validation is performed automatically.
+           Note that arguments specified directly take
+           precedence over arguments specified indirectly
+           through direct argument 'options'.
+        2. Inter-argument validation.
+        """
+        config = self.CONFIG(kwds.pop("options", {}))
+        config = config(kwds)
+        state_vars = validate_pyros_inputs(model, config)
+
+        return config, state_vars
+
+    @document_kwargs_from_configdict(
+        config=CONFIG,
+        section="Keyword Arguments",
+        indent_spacing=4,
+        width=72,
+        visibility=0,
+    )
     def solve(
         self,
         model,
@@ -853,21 +303,25 @@ def solve(
         ----------
         model: ConcreteModel
             The deterministic model.
-        first_stage_variables: list of Var
+        first_stage_variables: VarData, Var, or iterable of VarData/Var
             First-stage model variables (or design variables).
-        second_stage_variables: list of Var
+        second_stage_variables: VarData, Var, or iterable of VarData/Var
             Second-stage model variables (or control variables).
-        uncertain_params: list of Param
+        uncertain_params: ParamData, Param, or iterable of ParamData/Param
             Uncertain model parameters.
-            The `mutable` attribute for every uncertain parameter
-            objects must be set to True.
+            The `mutable` attribute for all uncertain parameter objects
+            must be set to True.
         uncertainty_set: UncertaintySet
             Uncertainty set against which the solution(s) returned
             will be confirmed to be robust.
-        local_solver: Solver
+        local_solver: str or solver type
             Subordinate local NLP solver.
-        global_solver: Solver
+            If a `str` is passed, then the `str` is cast to
+            ``SolverFactory(local_solver)``.
+        global_solver: str or solver type
             Subordinate global NLP solver.
+            If a `str` is passed, then the `str` is cast to
+            ``SolverFactory(global_solver)``.
 
         Returns
         -------
@@ -875,56 +329,41 @@ def solve(
             Summary of PyROS termination outcome.
 
         """
-
-        # === Add the explicit arguments to the config
-        config = self.CONFIG(kwds.pop('options', {}))
-        config.first_stage_variables = first_stage_variables
-        config.second_stage_variables = second_stage_variables
-        config.uncertain_params = uncertain_params
-        config.uncertainty_set = uncertainty_set
-        config.local_solver = local_solver
-        config.global_solver = global_solver
-
-        dev_options = kwds.pop('dev_options', {})
-        config.set_value(kwds)
-        config.set_value(dev_options)
-
-        model = model
-
-        # === Validate kwarg inputs
-        validate_kwarg_inputs(model, config)
-
-        # === Validate ability of grcs RO solver to handle this model
-        if not model_is_valid(model):
-            raise AttributeError(
-                "This model structure is not currently handled by the ROSolver."
-            )
-
-        # === Define nominal point if not specified
-        if len(config.nominal_uncertain_param_vals) == 0:
-            config.nominal_uncertain_param_vals = list(
-                p.value for p in config.uncertain_params
-            )
-        elif len(config.nominal_uncertain_param_vals) != len(config.uncertain_params):
-            raise AttributeError(
-                "The nominal_uncertain_param_vals list must be the same length"
-                "as the uncertain_params list"
-            )
-
-        # === Create data containers
         model_data = ROSolveResults()
-        model_data.timing = Bunch()
-
-        # === Start timer, run the algorithm
         model_data.timing = TimingData()
         with time_code(
             timing_data_obj=model_data.timing,
             code_block_name="main",
             is_main_timer=True,
         ):
-            # output intro and disclaimer
-            self._log_intro(logger=config.progress_logger, level=logging.INFO)
-            self._log_disclaimer(logger=config.progress_logger, level=logging.INFO)
+            kwds.update(
+                dict(
+                    first_stage_variables=first_stage_variables,
+                    second_stage_variables=second_stage_variables,
+                    uncertain_params=uncertain_params,
+                    uncertainty_set=uncertainty_set,
+                    local_solver=local_solver,
+                    global_solver=global_solver,
+                )
+            )
+
+            # we want to log the intro and disclaimer in
+            # advance of assembling the config.
+            # this helps clarify to the user that any
+            # messages logged during assembly of the config
+            # were, in fact, logged after PyROS was initiated
+            progress_logger = logger_domain(
+                kwds.get(
+                    "progress_logger",
+                    kwds.get("options", dict()).get(
+                        "progress_logger", default_pyros_solver_logger
+                    ),
+                )
+            )
+            self._log_intro(logger=progress_logger, level=logging.INFO)
+            self._log_disclaimer(logger=progress_logger, level=logging.INFO)
+
+            config, state_vars = self._resolve_and_validate_pyros_args(model, **kwds)
             self._log_config(
                 logger=config.progress_logger,
                 config=config,
@@ -940,15 +379,13 @@ def solve(
             util = Block(concrete=True)
             util.first_stage_variables = config.first_stage_variables
             util.second_stage_variables = config.second_stage_variables
+            util.state_vars = state_vars
             util.uncertain_params = config.uncertain_params
 
             model_data.util_block = unique_component_name(model, 'util')
             model.add_component(model_data.util_block, util)
             # Note:  model.component(model_data.util_block) is util
 
-            # === Validate uncertainty set happens here, requires util block for Cardinality and FactorModel sets
-            validate_uncertainty_set(config=config)
-
             # === Leads to a logger warning here for inactive obj when cloning
             model_data.original_model = model
             # === For keeping track of variables after cloning
@@ -990,22 +427,10 @@ def solve(
             # === Move bounds on control variables to explicit ineq constraints
             wm_util = model_data.working_model
 
-            # === Every non-fixed variable that is neither first-stage
-            #     nor second-stage is taken to be a state variable
-            fsv = ComponentSet(model_data.working_model.util.first_stage_variables)
-            ssv = ComponentSet(model_data.working_model.util.second_stage_variables)
-            sv = ComponentSet()
-            model_data.working_model.util.state_vars = []
-            for v in model_data.working_model.component_data_objects(Var):
-                if not v.fixed and v not in fsv | ssv | sv:
-                    model_data.working_model.util.state_vars.append(v)
-                    sv.add(v)
-
-            # Bounds on second stage variables and state variables are separation objectives,
-            #  they are brought in this was as explicit constraints
+            # cast bounds on second-stage and state variables to
+            # explicit constraints for separation objectives
             for c in model_data.working_model.util.second_stage_variables:
                 turn_bounds_to_constraints(c, wm_util, config)
-
             for c in model_data.working_model.util.state_vars:
                 turn_bounds_to_constraints(c, wm_util, config)
 
@@ -1085,131 +510,3 @@ def solve(
         config.progress_logger.info("=" * self._LOG_LINE_LENGTH)
 
         return return_soln
-
-
-def _generate_filtered_docstring():
-    """
-    Add Numpy-style 'Keyword arguments' section to `PyROS.solve()`
-    docstring.
-    """
-    cfg = PyROS.CONFIG()
-
-    # mandatory args already documented
-    exclude_args = [
-        "first_stage_variables",
-        "second_stage_variables",
-        "uncertain_params",
-        "uncertainty_set",
-        "local_solver",
-        "global_solver",
-    ]
-
-    indent_by = 8
-    width = 72
-    before = PyROS.solve.__doc__
-    section_name = "Keyword Arguments"
-
-    indent_str = ' ' * indent_by
-    wrap_width = width - indent_by
-    cfg = pyros_config()
-
-    arg_docs = []
-
-    def wrap_doc(doc, indent_by, width):
-        """
-        Wrap a string, accounting for paragraph
-        breaks ('\n\n') and bullet points (paragraphs
-        which, when dedented, are such that each line
-        starts with '- ' or '  ').
-        """
-        paragraphs = doc.split("\n\n")
-        wrapped_pars = []
-        for par in paragraphs:
-            lines = dedent(par).split("\n")
-            has_bullets = all(
-                line.startswith("- ") or line.startswith("  ")
-                for line in lines
-                if line != ""
-            )
-            if has_bullets:
-                # obtain strings of each bullet point
-                # (dedented, bullet dash and bullet indent removed)
-                bullet_groups = []
-                new_group = False
-                group = ""
-                for line in lines:
-                    new_group = line.startswith("- ")
-                    if new_group:
-                        bullet_groups.append(group)
-                        group = ""
-                    new_line = line[2:]
-                    group += f"{new_line}\n"
-                if group != "":
-                    # ensure last bullet not skipped
-                    bullet_groups.append(group)
-
-                # first entry is just ''; remove
-                bullet_groups = bullet_groups[1:]
-
-                # wrap each bullet point, then add bullet
-                # and indents as necessary
-                wrapped_groups = []
-                for group in bullet_groups:
-                    wrapped_groups.append(
-                        "\n".join(
-                            f"{'- ' if idx == 0 else '  '}{line}"
-                            for idx, line in enumerate(
-                                wrap(group, width - 2 - indent_by)
-                            )
-                        )
-                    )
-
-                # now combine bullets into single 'paragraph'
-                wrapped_pars.append(
-                    indent("\n".join(wrapped_groups), prefix=' ' * indent_by)
-                )
-            else:
-                wrapped_pars.append(
-                    indent(
-                        "\n".join(wrap(dedent(par), width=width - indent_by)),
-                        prefix=' ' * indent_by,
-                    )
-                )
-
-        return "\n\n".join(wrapped_pars)
-
-    section_header = indent(f"{section_name}\n" + "-" * len(section_name), indent_str)
-    for key, itm in cfg._data.items():
-        if key in exclude_args:
-            continue
-        arg_name = key
-        arg_dtype = itm.dtype_spec_str
-
-        if itm.is_optional:
-            if itm.document_default:
-                optional_str = f", default={repr(itm._default)}"
-            else:
-                optional_str = ", optional"
-        else:
-            optional_str = ""
-
-        arg_header = f"{indent_str}{arg_name} : {arg_dtype}{optional_str}"
-
-        # dedented_doc_str = dedent(itm.doc).replace("\n", ' ').strip()
-        if itm._doc is not None:
-            raw_arg_desc = itm._doc
-        else:
-            raw_arg_desc = itm._description
-
-        arg_description = wrap_doc(
-            raw_arg_desc, width=wrap_width, indent_by=indent_by + 4
-        )
-
-        arg_docs.append(f"{arg_header}\n{arg_description}")
-
-    kwargs_section_doc = "\n".join([section_header] + arg_docs)
-
-    return f"{before}\n{kwargs_section_doc}\n"
-
-
-PyROS.solve.__doc__ = _generate_filtered_docstring()
diff --git a/pyomo/contrib/pyros/pyros_algorithm_methods.py b/pyomo/contrib/pyros/pyros_algorithm_methods.py
index 4ae033b9498..cfb57b08c7f 100644
--- a/pyomo/contrib/pyros/pyros_algorithm_methods.py
+++ b/pyomo/contrib/pyros/pyros_algorithm_methods.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 '''
 Methods for the execution of the grcs algorithm
 '''
@@ -15,8 +26,9 @@
 )
 from pyomo.contrib.pyros.util import get_main_elapsed_time, coefficient_matching
 from pyomo.core.base import value
+from pyomo.core.expr import MonomialTermExpression
 from pyomo.common.collections import ComponentSet, ComponentMap
-from pyomo.core.base.var import _VarData as VarData
+from pyomo.core.base.var import VarData as VarData
 from itertools import chain
 from pyomo.common.dependencies import numpy as np
 
@@ -58,14 +70,17 @@ def get_dr_var_to_scaled_expr_map(
     ssv_dr_eq_zip = zip(second_stage_vars, decision_rule_eqns)
     for ssv_idx, (ssv, dr_eq) in enumerate(ssv_dr_eq_zip):
         for term in dr_eq.body.args:
-            is_ssv_term = (
-                isinstance(term.args[0], int)
-                and term.args[0] == -1
-                and isinstance(term.args[1], VarData)
-            )
-            if not is_ssv_term:
-                dr_var = term.args[1]
-                var_to_scaled_expr_map[dr_var] = term
+            if isinstance(term, MonomialTermExpression):
+                is_ssv_term = (
+                    isinstance(term.args[0], int)
+                    and term.args[0] == -1
+                    and isinstance(term.args[1], VarData)
+                )
+                if not is_ssv_term:
+                    dr_var = term.args[1]
+                    var_to_scaled_expr_map[dr_var] = term
+            elif isinstance(term, VarData):
+                var_to_scaled_expr_map[term] = MonomialTermExpression((1, term))
 
     return var_to_scaled_expr_map
 
@@ -794,7 +809,7 @@ def ROSolver_iterative_solve(model_data, config):
             len(scaled_violations) == len(separation_model.util.performance_constraints)
             and not separation_results.subsolver_error
             and not separation_results.time_out
-        )
+        ) or separation_results.all_discrete_scenarios_exhausted
 
         iter_log_record = IterationLogRecord(
             iteration=k,
diff --git a/pyomo/contrib/pyros/separation_problem_methods.py b/pyomo/contrib/pyros/separation_problem_methods.py
index b9659f044f4..18d0925bab0 100644
--- a/pyomo/contrib/pyros/separation_problem_methods.py
+++ b/pyomo/contrib/pyros/separation_problem_methods.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """
 Functions for the construction and solving of the GRCS separation problem via ROsolver
 """
@@ -7,7 +18,6 @@
 from pyomo.core.base import Var, Param
 from pyomo.common.collections import ComponentSet, ComponentMap
 from pyomo.common.dependencies import numpy as np
-from pyomo.contrib.pyros.util import ObjectiveType, get_time_from_solver
 from pyomo.contrib.pyros.solve_data import (
     DiscreteSeparationSolveCallResults,
     SeparationSolveCallResults,
@@ -26,9 +36,11 @@
 from pyomo.contrib.pyros.util import ABS_CON_CHECK_FEAS_TOL
 from pyomo.common.timing import TicTocTimer
 from pyomo.contrib.pyros.util import (
-    TIC_TOC_SOLVE_TIME_ATTR,
     adjust_solver_time_settings,
+    call_solver,
+    ObjectiveType,
     revert_solver_max_time_adjustment,
+    TIC_TOC_SOLVE_TIME_ATTR,
 )
 import os
 from copy import deepcopy
@@ -638,6 +650,7 @@ def perform_separation_loop(model_data, config, solve_globally):
                 solver_call_results=ComponentMap(),
                 solved_globally=solve_globally,
                 worst_case_perf_con=None,
+                all_discrete_scenarios_exhausted=True,
             )
 
         perf_con_to_maximize = sorted_priority_groups[
@@ -1058,6 +1071,7 @@ def solver_call_separation(
 
     separation_obj.activate()
 
+    solve_mode_adverb = "globally" if solve_globally else "locally"
     solve_call_results = SeparationSolveCallResults(
         solved_globally=solve_globally,
         time_out=False,
@@ -1065,7 +1079,6 @@ def solver_call_separation(
         found_violation=False,
         subsolver_error=False,
     )
-    timer = TicTocTimer()
     for idx, opt in enumerate(solvers):
         if idx > 0:
             config.progress_logger.warning(
@@ -1074,37 +1087,19 @@ def solver_call_separation(
                 f"separation of performance constraint {con_name_repr} "
                 f"in iteration {model_data.iteration}."
             )
-        orig_setting, custom_setting_present = adjust_solver_time_settings(
-            model_data.timing, opt, config
-        )
-        model_data.timing.start_timer(f"main.{solve_mode}_separation")
-        timer.tic(msg=None)
-        try:
-            results = opt.solve(
-                nlp_model,
-                tee=config.tee,
-                load_solutions=False,
-                symbolic_solver_labels=True,
-            )
-        except ApplicationError:
-            # account for possible external subsolver errors
-            # (such as segmentation faults, function evaluation
-            # errors, etc.)
-            adverb = "globally" if solve_globally else "locally"
-            config.progress_logger.error(
+        results = call_solver(
+            model=nlp_model,
+            solver=opt,
+            config=config,
+            timing_obj=model_data.timing,
+            timer_name=f"main.{solve_mode}_separation",
+            err_msg=(
                 f"Optimizer {repr(opt)} ({idx + 1} of {len(solvers)}) "
                 f"encountered exception attempting "
-                f"to {adverb} solve separation problem for constraint "
+                f"to {solve_mode_adverb} solve separation problem for constraint "
                 f"{con_name_repr} in iteration {model_data.iteration}."
-            )
-            raise
-        else:
-            setattr(results.solver, TIC_TOC_SOLVE_TIME_ATTR, timer.toc(msg=None))
-            model_data.timing.stop_timer(f"main.{solve_mode}_separation")
-        finally:
-            revert_solver_max_time_adjustment(
-                opt, orig_setting, custom_setting_present, config
-            )
+            ),
+        )
 
         # record termination condition for this particular solver
         solver_status_dict[str(opt)] = results.solver.termination_condition
diff --git a/pyomo/contrib/pyros/solve_data.py b/pyomo/contrib/pyros/solve_data.py
index 40a52757bae..73eee5202aa 100644
--- a/pyomo/contrib/pyros/solve_data.py
+++ b/pyomo/contrib/pyros/solve_data.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """
 Objects to contain all model data and solve results for the ROSolver
 """
@@ -336,16 +347,23 @@ class SeparationLoopResults:
     solver_call_results : ComponentMap
         Mapping from performance constraints to corresponding
         ``SeparationSolveCallResults`` objects.
-    worst_case_perf_con : None or int, optional
+    worst_case_perf_con : None or Constraint
         Performance constraint mapped to ``SeparationSolveCallResults``
         object in `self` corresponding to maximally violating
         separation problem solution.
+    all_discrete_scenarios_exhausted : bool, optional
+        For problems with discrete uncertainty sets,
+        True if all scenarios were explicitly accounted for in master
+        (which occurs if there have been
+        as many PyROS iterations as there are scenarios in the set)
+        False otherwise.
 
     Attributes
     ----------
     solver_call_results
     solved_globally
     worst_case_perf_con
+    all_discrete_scenarios_exhausted
     found_violation
     violating_param_realization
     scaled_violations
@@ -354,11 +372,18 @@ class SeparationLoopResults:
     time_out
     """
 
-    def __init__(self, solved_globally, solver_call_results, worst_case_perf_con):
+    def __init__(
+        self,
+        solved_globally,
+        solver_call_results,
+        worst_case_perf_con,
+        all_discrete_scenarios_exhausted=False,
+    ):
         """Initialize self (see class docstring)."""
         self.solver_call_results = solver_call_results
         self.solved_globally = solved_globally
         self.worst_case_perf_con = worst_case_perf_con
+        self.all_discrete_scenarios_exhausted = all_discrete_scenarios_exhausted
 
     @property
     def found_violation(self):
@@ -588,6 +613,17 @@ def get_violating_attr(self, attr_name):
         """
         return getattr(self.main_loop_results, attr_name, None)
 
+    @property
+    def all_discrete_scenarios_exhausted(self):
+        """
+        bool : For problems where the uncertainty set is of type
+        DiscreteScenarioSet,
+        True if last master problem solved explicitly
+        accounts for all scenarios in the uncertainty set,
+        False otherwise.
+        """
+        return self.get_violating_attr("all_discrete_scenarios_exhausted")
+
     @property
     def worst_case_perf_con(self):
         """
diff --git a/pyomo/contrib/pyros/tests/__init__.py b/pyomo/contrib/pyros/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/pyros/tests/__init__.py
+++ b/pyomo/contrib/pyros/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/pyros/tests/test_config.py b/pyomo/contrib/pyros/tests/test_config.py
new file mode 100644
index 00000000000..166fbada4ff
--- /dev/null
+++ b/pyomo/contrib/pyros/tests/test_config.py
@@ -0,0 +1,620 @@
+"""
+Test objects for construction of PyROS ConfigDict.
+"""
+
+import logging
+import unittest
+
+from pyomo.core.base import ConcreteModel, Var, VarData
+from pyomo.common.log import LoggingIntercept
+from pyomo.common.errors import ApplicationError
+from pyomo.core.base.param import Param, ParamData
+from pyomo.contrib.pyros.config import (
+    InputDataStandardizer,
+    mutable_param_validator,
+    logger_domain,
+    SolverNotResolvable,
+    positive_int_or_minus_one,
+    pyros_config,
+    SolverIterable,
+    SolverResolvable,
+)
+from pyomo.contrib.pyros.util import ObjectiveType
+from pyomo.opt import SolverFactory, SolverResults
+from pyomo.contrib.pyros.uncertainty_sets import BoxSet
+from pyomo.common.dependencies import numpy_available
+
+
+class TestInputDataStandardizer(unittest.TestCase):
+    """
+    Test standardizer method for Pyomo component-type inputs.
+    """
+
+    def test_single_component_data(self):
+        """
+        Test standardizer works for single component
+        data-type entry.
+        """
+        mdl = ConcreteModel()
+        mdl.v = Var([0, 1])
+
+        standardizer_func = InputDataStandardizer(Var, VarData)
+
+        standardizer_input = mdl.v[0]
+        standardizer_output = standardizer_func(standardizer_input)
+
+        self.assertIsInstance(
+            standardizer_output,
+            list,
+            msg=(
+                "Standardized output should be of type list, "
+                f"but is of type {standardizer_output.__class__.__name__}."
+            ),
+        )
+        self.assertEqual(
+            len(standardizer_output),
+            1,
+            msg="Length of standardizer output is not as expected.",
+        )
+        self.assertIs(
+            standardizer_output[0],
+            mdl.v[0],
+            msg=(
+                f"Entry {standardizer_output[0]} (id {id(standardizer_output[0])}) "
+                "is not identical to "
+                f"input component data object {mdl.v[0]} "
+                f"(id {id(mdl.v[0])})"
+            ),
+        )
+
+    def test_standardizer_indexed_component(self):
+        """
+        Test component standardizer works on indexed component.
+        """
+        mdl = ConcreteModel()
+        mdl.v = Var([0, 1])
+
+        standardizer_func = InputDataStandardizer(Var, VarData)
+
+        standardizer_input = mdl.v
+        standardizer_output = standardizer_func(standardizer_input)
+
+        self.assertIsInstance(
+            standardizer_output,
+            list,
+            msg=(
+                "Standardized output should be of type list, "
+                f"but is of type {standardizer_output.__class__.__name__}."
+            ),
+        )
+        self.assertEqual(
+            len(standardizer_output),
+            2,
+            msg="Length of standardizer output is not as expected.",
+        )
+        enum_zip = enumerate(zip(standardizer_input.values(), standardizer_output))
+        for idx, (input, output) in enum_zip:
+            self.assertIs(
+                input,
+                output,
+                msg=(
+                    f"Entry {input} (id {id(input)}) "
+                    "is not identical to "
+                    f"input component data object {output} "
+                    f"(id {id(output)})"
+                ),
+            )
+
+    def test_standardizer_multiple_components(self):
+        """
+        Test standardizer works on sequence of components.
+        """
+        mdl = ConcreteModel()
+        mdl.v = Var([0, 1])
+        mdl.x = Var(["a", "b"])
+
+        standardizer_func = InputDataStandardizer(Var, VarData)
+
+        standardizer_input = [mdl.v[0], mdl.x]
+        standardizer_output = standardizer_func(standardizer_input)
+        expected_standardizer_output = [mdl.v[0], mdl.x["a"], mdl.x["b"]]
+
+        self.assertIsInstance(
+            standardizer_output,
+            list,
+            msg=(
+                "Standardized output should be of type list, "
+                f"but is of type {standardizer_output.__class__.__name__}."
+            ),
+        )
+        self.assertEqual(
+            len(standardizer_output),
+            len(expected_standardizer_output),
+            msg="Length of standardizer output is not as expected.",
+        )
+        enum_zip = enumerate(zip(expected_standardizer_output, standardizer_output))
+        for idx, (input, output) in enum_zip:
+            self.assertIs(
+                input,
+                output,
+                msg=(
+                    f"Entry {input} (id {id(input)}) "
+                    "is not identical to "
+                    f"input component data object {output} "
+                    f"(id {id(output)})"
+                ),
+            )
+
+    def test_standardizer_invalid_duplicates(self):
+        """
+        Test standardizer raises exception if input contains duplicates
+        and duplicates are not allowed.
+        """
+        mdl = ConcreteModel()
+        mdl.v = Var([0, 1])
+        mdl.x = Var(["a", "b"])
+
+        standardizer_func = InputDataStandardizer(Var, VarData, allow_repeats=False)
+
+        exc_str = r"Standardized.*list.*contains duplicate entries\."
+        with self.assertRaisesRegex(ValueError, exc_str):
+            standardizer_func([mdl.x, mdl.v, mdl.x])
+
+    def test_standardizer_invalid_type(self):
+        """
+        Test standardizer raises exception as expected
+        when input is of invalid type.
+        """
+        standardizer_func = InputDataStandardizer(Var, VarData)
+
+        exc_str = r"Input object .*is not of valid component type.*"
+        with self.assertRaisesRegex(TypeError, exc_str):
+            standardizer_func(2)
+
+    def test_standardizer_iterable_with_invalid_type(self):
+        """
+        Test standardizer raises exception as expected
+        when input is an iterable with entries of invalid type.
+        """
+        mdl = ConcreteModel()
+        mdl.v = Var([0, 1])
+        standardizer_func = InputDataStandardizer(Var, VarData)
+
+        exc_str = r"Input object .*entry of iterable.*is not of valid component type.*"
+        with self.assertRaisesRegex(TypeError, exc_str):
+            standardizer_func([mdl.v, 2])
+
+    def test_standardizer_invalid_str_passed(self):
+        """
+        Test standardizer raises exception as expected
+        when input is of invalid type str.
+        """
+        standardizer_func = InputDataStandardizer(Var, VarData)
+
+        exc_str = r"Input object .*is not of valid component type.*"
+        with self.assertRaisesRegex(TypeError, exc_str):
+            standardizer_func("abcd")
+
+    def test_standardizer_invalid_uninitialized_params(self):
+        """
+        Test standardizer raises exception when Param with
+        uninitialized entries passed.
+        """
+        standardizer_func = InputDataStandardizer(
+            ctype=Param, cdatatype=ParamData, ctype_validator=mutable_param_validator
+        )
+
+        mdl = ConcreteModel()
+        mdl.p = Param([0, 1])
+
+        exc_str = r"Length of .*does not match that of.*index set"
+        with self.assertRaisesRegex(ValueError, exc_str):
+            standardizer_func(mdl.p)
+
+    def test_standardizer_invalid_immutable_params(self):
+        """
+        Test standardizer raises exception when immutable
+        Param object(s) passed.
+        """
+        standardizer_func = InputDataStandardizer(
+            ctype=Param, cdatatype=ParamData, ctype_validator=mutable_param_validator
+        )
+
+        mdl = ConcreteModel()
+        mdl.p = Param([0, 1], initialize=1)
+
+        exc_str = r"Param object with name .*immutable"
+        with self.assertRaisesRegex(ValueError, exc_str):
+            standardizer_func(mdl.p)
+
+    def test_standardizer_valid_mutable_params(self):
+        """
+        Test Param-like standardizer works as expected for sequence
+        of valid mutable Param objects.
+        """
+        mdl = ConcreteModel()
+        mdl.p1 = Param([0, 1], initialize=0, mutable=True)
+        mdl.p2 = Param(["a", "b"], initialize=1, mutable=True)
+
+        standardizer_func = InputDataStandardizer(
+            ctype=Param, cdatatype=ParamData, ctype_validator=mutable_param_validator
+        )
+
+        standardizer_input = [mdl.p1[0], mdl.p2]
+        standardizer_output = standardizer_func(standardizer_input)
+        expected_standardizer_output = [mdl.p1[0], mdl.p2["a"], mdl.p2["b"]]
+
+        self.assertIsInstance(
+            standardizer_output,
+            list,
+            msg=(
+                "Standardized output should be of type list, "
+                f"but is of type {standardizer_output.__class__.__name__}."
+            ),
+        )
+        self.assertEqual(
+            len(standardizer_output),
+            len(expected_standardizer_output),
+            msg="Length of standardizer output is not as expected.",
+        )
+        enum_zip = enumerate(zip(expected_standardizer_output, standardizer_output))
+        for idx, (input, output) in enum_zip:
+            self.assertIs(
+                input,
+                output,
+                msg=(
+                    f"Entry {input} (id {id(input)}) "
+                    "is not identical to "
+                    f"input component data object {output} "
+                    f"(id {id(output)})"
+                ),
+            )
+
+
+AVAILABLE_SOLVER_TYPE_NAME = "available_pyros_test_solver"
+
+
+class AvailableSolver:
+    """
+    Perennially available placeholder solver.
+    """
+
+    def available(self, exception_flag=False):
+        """
+        Check solver available.
+        """
+        return True
+
+    def solve(self, model, **kwds):
+        """
+        Return SolverResults object with 'unknown' termination
+        condition. Model remains unchanged.
+        """
+        return SolverResults()
+
+
+class UnavailableSolver:
+    def available(self, exception_flag=True):
+        if exception_flag:
+            raise ApplicationError(f"Solver {self.__class__} not available")
+        return False
+
+    def solve(self, model, *args, **kwargs):
+        return SolverResults()
+
+
+class TestSolverResolvable(unittest.TestCase):
+    """
+    Test PyROS standardizer for solver-type objects.
+    """
+
+    def setUp(self):
+        SolverFactory.register(AVAILABLE_SOLVER_TYPE_NAME)(AvailableSolver)
+
+    def tearDown(self):
+        SolverFactory.unregister(AVAILABLE_SOLVER_TYPE_NAME)
+
+    def test_solver_resolvable_valid_str(self):
+        """
+        Test solver resolvable class is valid for string
+        type.
+        """
+        solver_str = AVAILABLE_SOLVER_TYPE_NAME
+        standardizer_func = SolverResolvable()
+        solver = standardizer_func(solver_str)
+        expected_solver_type = type(SolverFactory(solver_str))
+
+        self.assertIsInstance(
+            solver,
+            type(SolverFactory(solver_str)),
+            msg=(
+                "SolverResolvable object should be of type "
+                f"{expected_solver_type.__name__}, "
+                f"but got object of type {solver.__class__.__name__}."
+            ),
+        )
+
+    def test_solver_resolvable_valid_solver_type(self):
+        """
+        Test solver resolvable class is valid for string
+        type.
+        """
+        solver = SolverFactory(AVAILABLE_SOLVER_TYPE_NAME)
+        standardizer_func = SolverResolvable()
+        standardized_solver = standardizer_func(solver)
+
+        self.assertIs(
+            solver,
+            standardized_solver,
+            msg=(
+                f"Test solver {solver} and standardized solver "
+                f"{standardized_solver} are not identical."
+            ),
+        )
+
+    def test_solver_resolvable_invalid_type(self):
+        """
+        Test solver resolvable object raises expected
+        exception when invalid entry is provided.
+        """
+        invalid_object = 2
+        standardizer_func = SolverResolvable(solver_desc="local solver")
+
+        exc_str = (
+            r"Cannot cast object `2` to a Pyomo optimizer.*"
+            r"local solver.*got type int.*"
+        )
+        with self.assertRaisesRegex(SolverNotResolvable, exc_str):
+            standardizer_func(invalid_object)
+
+    def test_solver_resolvable_unavailable_solver(self):
+        """
+        Test solver standardizer fails in event solver is
+        unavailable.
+        """
+        unavailable_solver = UnavailableSolver()
+        standardizer_func = SolverResolvable(
+            solver_desc="local solver", require_available=True
+        )
+
+        exc_str = r"Solver.*UnavailableSolver.*not available"
+        with self.assertRaisesRegex(ApplicationError, exc_str):
+            with LoggingIntercept(level=logging.ERROR) as LOG:
+                standardizer_func(unavailable_solver)
+
+        error_msgs = LOG.getvalue()[:-1]
+        self.assertRegex(
+            error_msgs, r"Output of `available\(\)` method.*local solver.*"
+        )
+
+
+class TestSolverIterable(unittest.TestCase):
+    """
+    Test standardizer method for iterable of solvers,
+    used to validate `backup_local_solvers` and `backup_global_solvers`
+    arguments.
+    """
+
+    def setUp(self):
+        SolverFactory.register(AVAILABLE_SOLVER_TYPE_NAME)(AvailableSolver)
+
+    def tearDown(self):
+        SolverFactory.unregister(AVAILABLE_SOLVER_TYPE_NAME)
+
+    def test_solver_iterable_valid_list(self):
+        """
+        Test solver type standardizer works for list of valid
+        objects castable to solver.
+        """
+        solver_list = [
+            AVAILABLE_SOLVER_TYPE_NAME,
+            SolverFactory(AVAILABLE_SOLVER_TYPE_NAME),
+        ]
+        expected_solver_types = [AvailableSolver] * 2
+        standardizer_func = SolverIterable()
+
+        standardized_solver_list = standardizer_func(solver_list)
+
+        # check list of solver types returned
+        for idx, standardized_solver in enumerate(standardized_solver_list):
+            self.assertIsInstance(
+                standardized_solver,
+                expected_solver_types[idx],
+                msg=(
+                    f"Standardized solver {standardized_solver} "
+                    f"(index {idx}) expected to be of type "
+                    f"{expected_solver_types[idx].__name__}, "
+                    f"but is of type {standardized_solver.__class__.__name__}"
+                ),
+            )
+
+        # second entry of standardized solver list should be the same
+        # object as that of input list, since the input solver is a Pyomo
+        # solver type
+        self.assertIs(
+            standardized_solver_list[1],
+            solver_list[1],
+            msg=(
+                f"Test solver {solver_list[1]} and standardized solver "
+                f"{standardized_solver_list[1]} should be identical."
+            ),
+        )
+
+    def test_solver_iterable_valid_str(self):
+        """
+        Test SolverIterable raises exception when str passed.
+        """
+        solver_str = AVAILABLE_SOLVER_TYPE_NAME
+        standardizer_func = SolverIterable()
+
+        solver_list = standardizer_func(solver_str)
+        self.assertEqual(
+            len(solver_list), 1, "Standardized solver list is not of expected length"
+        )
+
+    def test_solver_iterable_unavailable_solver(self):
+        """
+        Test SolverIterable addresses unavailable solvers appropriately.
+        """
+        solvers = (AvailableSolver(), UnavailableSolver())
+
+        standardizer_func = SolverIterable(
+            require_available=True,
+            filter_by_availability=True,
+            solver_desc="example solver list",
+        )
+        exc_str = r"Solver.*UnavailableSolver.* not available"
+        with self.assertRaisesRegex(ApplicationError, exc_str):
+            standardizer_func(solvers)
+        with self.assertRaisesRegex(ApplicationError, exc_str):
+            standardizer_func(solvers, filter_by_availability=False)
+
+        standardized_solver_list = standardizer_func(
+            solvers, filter_by_availability=True, require_available=False
+        )
+        self.assertEqual(
+            len(standardized_solver_list),
+            1,
+            msg=("Length of filtered standardized solver list not as " "expected."),
+        )
+        self.assertIs(
+            standardized_solver_list[0],
+            solvers[0],
+            msg="Entry of filtered standardized solver list not as expected.",
+        )
+
+        standardized_solver_list = standardizer_func(
+            solvers, filter_by_availability=False, require_available=False
+        )
+        self.assertEqual(
+            len(standardized_solver_list),
+            2,
+            msg=("Length of filtered standardized solver list not as " "expected."),
+        )
+        self.assertEqual(
+            standardized_solver_list,
+            list(solvers),
+            msg="Entry of filtered standardized solver list not as expected.",
+        )
+
+    def test_solver_iterable_invalid_list(self):
+        """
+        Test SolverIterable raises exception if iterable contains
+        at least one invalid object.
+        """
+        invalid_object = [AVAILABLE_SOLVER_TYPE_NAME, 2]
+        standardizer_func = SolverIterable(solver_desc="backup solver")
+
+        exc_str = (
+            r"Cannot cast object `2` to a Pyomo optimizer.*"
+            r"backup solver.*index 1.*got type int.*"
+        )
+        with self.assertRaisesRegex(SolverNotResolvable, exc_str):
+            standardizer_func(invalid_object)
+
+
+class TestPyROSConfig(unittest.TestCase):
+    """
+    Test PyROS ConfigDict behaves as expected.
+    """
+
+    CONFIG = pyros_config()
+
+    def test_config_objective_focus(self):
+        """
+        Test config parses objective focus as expected.
+        """
+        config = self.CONFIG()
+
+        for obj_focus_name in ["nominal", "worst_case"]:
+            config.objective_focus = obj_focus_name
+            self.assertEqual(
+                config.objective_focus,
+                ObjectiveType[obj_focus_name],
+                msg="Objective focus not set as expected.",
+            )
+
+        for obj_focus in ObjectiveType:
+            config.objective_focus = obj_focus
+            self.assertEqual(
+                config.objective_focus,
+                obj_focus,
+                msg="Objective focus not set as expected.",
+            )
+
+        invalid_focus = "test_example"
+        exc_str = f".*{invalid_focus!r} is not a valid ObjectiveType"
+        with self.assertRaisesRegex(ValueError, exc_str):
+            config.objective_focus = invalid_focus
+
+
+class TestPositiveIntOrMinusOne(unittest.TestCase):
+    """
+    Test validator for -1 or positive int works as expected.
+    """
+
+    def test_positive_int_or_minus_one(self):
+        """
+        Test positive int or -1 validator works as expected.
+        """
+        standardizer_func = positive_int_or_minus_one
+        ans = standardizer_func(1.0)
+        self.assertEqual(
+            ans,
+            1,
+            msg=f"{positive_int_or_minus_one.__name__} output value not as expected.",
+        )
+        self.assertIs(
+            type(ans),
+            int,
+            msg=f"{positive_int_or_minus_one.__name__} output type not as expected.",
+        )
+
+        ans = standardizer_func(-1.0)
+        self.assertEqual(
+            ans,
+            -1,
+            msg=f"{positive_int_or_minus_one.__name__} output value not as expected.",
+        )
+        self.assertIs(
+            type(ans),
+            int,
+            msg=f"{positive_int_or_minus_one.__name__} output type not as expected.",
+        )
+
+        exc_str = r"Expected positive int or -1, but received value.*"
+        with self.assertRaisesRegex(ValueError, exc_str):
+            standardizer_func(1.5)
+        with self.assertRaisesRegex(ValueError, exc_str):
+            standardizer_func(0)
+
+
+class TestLoggerDomain(unittest.TestCase):
+    """
+    Test logger type domain validator.
+    """
+
+    def test_logger_type(self):
+        """
+        Test logger type validator.
+        """
+        standardizer_func = logger_domain
+        mylogger = logging.getLogger("example")
+        self.assertIs(
+            standardizer_func(mylogger),
+            mylogger,
+            msg=f"{standardizer_func.__name__} output not as expected",
+        )
+        self.assertIs(
+            standardizer_func(mylogger.name),
+            mylogger,
+            msg=f"{standardizer_func.__name__} output not as expected",
+        )
+
+        exc_str = r"A logger name must be a string"
+        with self.assertRaisesRegex(Exception, exc_str):
+            standardizer_func(2)
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/pyomo/contrib/pyros/tests/test_grcs.py b/pyomo/contrib/pyros/tests/test_grcs.py
index 8de1c2666b9..f2954750a16 100644
--- a/pyomo/contrib/pyros/tests/test_grcs.py
+++ b/pyomo/contrib/pyros/tests/test_grcs.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 '''
 Unit tests for the grcs API
 One class per function being tested, minimum one test per class
@@ -8,6 +19,7 @@
 from pyomo.common.collections import ComponentSet, ComponentMap
 from pyomo.common.config import ConfigBlock, ConfigValue
 from pyomo.core.base.set_types import NonNegativeIntegers
+from pyomo.core.base.var import VarData
 from pyomo.core.expr import (
     identify_variables,
     identify_mutable_parameters,
@@ -18,7 +30,6 @@
     selective_clone,
     add_decision_rule_variables,
     add_decision_rule_constraints,
-    model_is_valid,
     turn_bounds_to_constraints,
     transform_to_standard_form,
     ObjectiveType,
@@ -31,6 +42,7 @@
 from pyomo.contrib.pyros.util import get_vars_from_component
 from pyomo.contrib.pyros.util import identify_objective_functions
 from pyomo.common.collections import Bunch
+from pyomo.repn.plugins import nl_writer as pyomo_nl_writer
 import time
 import math
 from pyomo.contrib.pyros.util import time_code
@@ -57,7 +69,7 @@
 from pyomo.common.dependencies import numpy as np, numpy_available
 from pyomo.common.dependencies import scipy as sp, scipy_available
 from pyomo.environ import maximize as pyo_max
-from pyomo.common.errors import ApplicationError
+from pyomo.common.errors import ApplicationError, InfeasibleConstraintException
 from pyomo.opt import (
     SolverResults,
     SolverStatus,
@@ -120,6 +132,9 @@
     scip_license_is_valid = False
     scip_version = (0, 0, 0)
 
+_ipopt = SolverFactory("ipopt")
+ipopt_available = _ipopt.available(exception_flag=False)
+
 
 # @SolverFactory.register("time_delay_solver")
 class TimeDelaySolver(object):
@@ -137,7 +152,7 @@ def __init__(self, calls_to_sleep, max_time, sub_solver):
         self.num_calls = 0
         self.options = Bunch()
 
-    def available(self):
+    def available(self, exception_flag=True):
         return True
 
     def license_is_valid(self):
@@ -558,22 +573,30 @@ def test_dr_eqns_form_correct(self):
                 dr_polynomial_terms, indexed_dr_var.values(), dr_monomial_param_combos
             )
             for idx, (term, dr_var, param_combo) in enumerate(dr_polynomial_zip):
-                # term should be a monomial expression of form
-                # (uncertain parameter product) * (decision rule variable)
-                # so length of expression object should be 2
-                self.assertEqual(
-                    len(term.args),
-                    2,
-                    msg=(
-                        f"Length of `args` attribute of term {str(term)} "
-                        f"of DR equation {dr_eq.name!r} is not as expected. "
-                        f"Args: {term.args}"
-                    ),
-                )
+                # term should be either a monomial expression or scalar variable
+                if isinstance(term, MonomialTermExpression):
+                    # should be of form (uncertain parameter product) *
+                    # (decision rule variable) so length of expression
+                    # object should be 2
+                    self.assertEqual(
+                        len(term.args),
+                        2,
+                        msg=(
+                            f"Length of `args` attribute of term {str(term)} "
+                            f"of DR equation {dr_eq.name!r} is not as expected. "
+                            f"Args: {term.args}"
+                        ),
+                    )
+
+                    # check that uncertain parameters participating in
+                    # the monomial are as expected
+                    param_product_multiplicand = term.args[0]
+                    dr_var_multiplicand = term.args[1]
+                else:
+                    self.assertIsInstance(term, VarData)
+                    param_product_multiplicand = 1
+                    dr_var_multiplicand = term
 
-                # check that uncertain parameters participating in
-                # the monomial are as expected
-                param_product_multiplicand = term.args[0]
                 if idx == 0:
                     # static DR term
                     param_combo_found_in_term = (param_product_multiplicand,)
@@ -599,7 +622,6 @@ def test_dr_eqns_form_correct(self):
 
                 # check that DR variable participating in the monomial
                 # is as expected
-                dr_var_multiplicand = term.args[1]
                 self.assertIs(
                     dr_var_multiplicand,
                     dr_var,
@@ -610,21 +632,6 @@ def test_dr_eqns_form_correct(self):
                 )
 
 
-class testModelIsValid(unittest.TestCase):
-    def test_model_is_valid_via_possible_inputs(self):
-        m = ConcreteModel()
-        m.x = Var()
-        m.obj1 = Objective(expr=m.x**2)
-        self.assertTrue(model_is_valid(m))
-        m.obj2 = Objective(expr=m.x)
-        self.assertFalse(model_is_valid(m))
-        m.obj2.deactivate()
-        self.assertTrue(model_is_valid(m))
-        m.del_component("obj1")
-        m.del_component("obj2")
-        self.assertFalse(model_is_valid(m))
-
-
 class testTurnBoundsToConstraints(unittest.TestCase):
     def test_bounds_to_constraints(self):
         m = ConcreteModel()
@@ -3549,10 +3556,7 @@ class behaves like a regular Python list.
         # assigning to slices should work fine
         all_sets[3:] = [BoxSet([[1, 1.5]]), BoxSet([[1, 3]])]
 
-    @unittest.skipUnless(
-        SolverFactory('ipopt').available(exception_flag=False),
-        "Local NLP solver is not available.",
-    )
+    @unittest.skipUnless(ipopt_available, "IPOPT is not available.")
     def test_uncertainty_set_with_correct_params(self):
         '''
         Case in which the UncertaintySet is constructed using the uncertain_param objects from the model to
@@ -3591,10 +3595,7 @@ def test_uncertainty_set_with_correct_params(self):
             " be the same uncertain param Var objects in the original model.",
         )
 
-    @unittest.skipUnless(
-        SolverFactory('ipopt').available(exception_flag=False),
-        "Local NLP solver is not available.",
-    )
+    @unittest.skipUnless(ipopt_available, "IPOPT is not available.")
     def test_uncertainty_set_with_incorrect_params(self):
         '''
         Case in which the set is constructed using  uncertain_param objects which are Params instead of
@@ -3795,6 +3796,7 @@ def test_solve_master(self):
         config.declare(
             "progress_logger", ConfigValue(default=logging.getLogger(__name__))
         )
+        config.declare("symbolic_solver_labels", ConfigValue(default=False))
 
         with time_code(master_data.timing, "main", is_main_timer=True):
             master_soln = solve_master(master_data, config)
@@ -4341,14 +4343,16 @@ def test_separation_terminate_time_limit(self):
         )
 
     @unittest.skipUnless(
-        SolverFactory('gams').license_is_valid()
-        and SolverFactory('baron').license_is_valid(),
-        "Global NLP solver is not available and licensed.",
+        ipopt_available
+        and SolverFactory('gams').license_is_valid()
+        and SolverFactory('baron').license_is_valid()
+        and SolverFactory("scip").license_is_valid(),
+        "IPOPT not available or one of GAMS/BARON/SCIP not licensed",
     )
-    def test_gams_successful_time_limit(self):
+    def test_pyros_subsolver_time_limit_adjustment(self):
         """
-        Test PyROS time limit status returned in event
-        separation problem times out.
+        Check that PyROS does not ultimately alter state of
+        subordinate solver options due to time limit adjustments.
         """
         m = ConcreteModel()
         m.x1 = Var(initialize=0, bounds=(0, None))
@@ -4367,20 +4371,26 @@ def test_gams_successful_time_limit(self):
         # Instantiate the PyROS solver
         pyros_solver = SolverFactory("pyros")
 
-        # Define subsolvers utilized in the algorithm
-        # two GAMS solvers, one of which has reslim set
-        # (overridden when invoked in PyROS)
+        # subordinate solvers to test.
+        # for testing, we pass each as the 'local' solver,
+        # and the BARON solver without custom options
+        # as the 'global' solver
+        baron_no_options = SolverFactory("baron")
         local_subsolvers = [
             SolverFactory("gams:conopt"),
             SolverFactory("gams:conopt"),
             SolverFactory("ipopt"),
+            SolverFactory("ipopt", options={"max_cpu_time": 300}),
+            SolverFactory("scip"),
+            SolverFactory("scip", options={"limits/time": 300}),
+            baron_no_options,
+            SolverFactory("baron", options={"MaxTime": 300}),
         ]
         local_subsolvers[0].options["add_options"] = ["option reslim=100;"]
-        global_subsolver = SolverFactory("baron")
-        global_subsolver.options["MaxTime"] = 300
 
         # Call the PyROS solver
         for idx, opt in enumerate(local_subsolvers):
+            original_solver_options = opt.options.copy()
             results = pyros_solver.solve(
                 model=m,
                 first_stage_variables=[m.x1, m.x2],
@@ -4388,68 +4398,25 @@ def test_gams_successful_time_limit(self):
                 uncertain_params=[m.u],
                 uncertainty_set=interval,
                 local_solver=opt,
-                global_solver=global_subsolver,
+                global_solver=baron_no_options,
                 objective_focus=ObjectiveType.worst_case,
                 solve_master_globally=True,
                 time_limit=100,
             )
-
             self.assertEqual(
                 results.pyros_termination_condition,
                 pyrosTerminationCondition.robust_optimal,
                 msg=(
-                    f"Returned termination condition with local "
-                    "subsolver {idx + 1} of 2 is not robust_optimal."
+                    "Returned termination condition with local "
+                    f"subsolver {idx + 1} of 2 is not robust_optimal."
                 ),
             )
-
-        # check first local subsolver settings
-        # remain unchanged after PyROS exit
-        self.assertEqual(
-            len(list(local_subsolvers[0].options["add_options"])),
-            1,
-            msg=(
-                f"Local subsolver {local_subsolvers[0]} options 'add_options'"
-                "were changed by PyROS"
-            ),
-        )
-        self.assertEqual(
-            local_subsolvers[0].options["add_options"][0],
-            "option reslim=100;",
-            msg=(
-                f"Local subsolver {local_subsolvers[0]} setting "
-                "'add_options' was modified "
-                "by PyROS, but changes were not properly undone"
-            ),
-        )
-
-        # check global subsolver settings unchanged
-        self.assertEqual(
-            len(list(global_subsolver.options.keys())),
-            1,
-            msg=(f"Global subsolver {global_subsolver} options were changed by PyROS"),
-        )
-        self.assertEqual(
-            global_subsolver.options["MaxTime"],
-            300,
-            msg=(
-                f"Global subsolver {global_subsolver} setting "
-                "'MaxTime' was modified "
-                "by PyROS, but changes were not properly undone"
-            ),
-        )
-
-        # check other local subsolvers remain unchanged
-        for slvr, key in zip(local_subsolvers[1:], ["add_options", "max_cpu_time"]):
-            # no custom options were added to the `options`
-            # attribute of the optimizer, so any attribute
-            # of `options` should be `None`
-            self.assertIs(
-                getattr(slvr.options, key, None),
-                None,
+            self.assertEqual(
+                opt.options,
+                original_solver_options,
                 msg=(
-                    f"Local subsolver {slvr} setting '{key}' was added "
-                    "by PyROS, but not reverted"
+                    f"Options for subordinate solver {opt} were changed "
+                    "by PyROS, and the changes wee not properly reverted."
                 ),
             )
 
@@ -4650,6 +4617,76 @@ def test_discrete_separation_subsolver_error(self):
             ),
         )
 
+    @unittest.skipUnless(ipopt_available, "IPOPT is not available.")
+    def test_pyros_nl_writer_tol(self):
+        """
+        Test PyROS subsolver call routine behavior
+        with respect to the NL writer tolerance is as
+        expected.
+        """
+        m = ConcreteModel()
+        m.q = Param(initialize=1, mutable=True)
+        m.x1 = Var(initialize=1, bounds=(0, 1))
+        m.x2 = Var(initialize=2, bounds=(0, m.q))
+        m.obj = Objective(expr=m.x1 + m.x2)
+
+        # fixed just inside the PyROS-specified NL writer tolerance.
+        m.x1.fix(m.x1.upper + 9.9e-5)
+
+        current_nl_writer_tol = pyomo_nl_writer.TOL
+        ipopt_solver = SolverFactory("ipopt")
+        pyros_solver = SolverFactory("pyros")
+
+        pyros_solver.solve(
+            model=m,
+            first_stage_variables=[m.x1],
+            second_stage_variables=[m.x2],
+            uncertain_params=[m.q],
+            uncertainty_set=BoxSet([[0, 1]]),
+            local_solver=ipopt_solver,
+            global_solver=ipopt_solver,
+            decision_rule_order=0,
+            solve_master_globally=False,
+            bypass_global_separation=True,
+        )
+
+        self.assertEqual(
+            pyomo_nl_writer.TOL,
+            current_nl_writer_tol,
+            msg="Pyomo NL writer tolerance not restored as expected.",
+        )
+
+        # fixed just outside the PyROS-specified NL writer tolerance.
+        # this should be exceptional.
+        m.x1.fix(m.x1.upper + 1.01e-4)
+
+        err_msg = (
+            "model contains a trivially infeasible variable.*x1"
+            ".*fixed.*outside bounds"
+        )
+        with self.assertRaisesRegex(InfeasibleConstraintException, err_msg):
+            pyros_solver.solve(
+                model=m,
+                first_stage_variables=[m.x1],
+                second_stage_variables=[m.x2],
+                uncertain_params=[m.q],
+                uncertainty_set=BoxSet([[0, 1]]),
+                local_solver=ipopt_solver,
+                global_solver=ipopt_solver,
+                decision_rule_order=0,
+                solve_master_globally=False,
+                bypass_global_separation=True,
+            )
+
+        self.assertEqual(
+            pyomo_nl_writer.TOL,
+            current_nl_writer_tol,
+            msg=(
+                "Pyomo NL writer tolerance not restored as expected "
+                "after exceptional test."
+            ),
+        )
+
     @unittest.skipUnless(
         baron_license_is_valid, "Global NLP solver is not available and licensed."
     )
@@ -5406,16 +5443,14 @@ def test_multiple_objs(self):
 
         # check validation error raised due to multiple objectives
         with self.assertRaisesRegex(
-            AttributeError,
-            "This model structure is not currently handled by the ROSolver.",
+            ValueError, r"Expected model with exactly 1 active objective.*has 3"
         ):
             pyros_solver.solve(**solve_kwargs)
 
         # check validation error raised due to multiple objectives
         m.b.obj.deactivate()
         with self.assertRaisesRegex(
-            AttributeError,
-            "This model structure is not currently handled by the ROSolver.",
+            ValueError, r"Expected model with exactly 1 active objective.*has 2"
         ):
             pyros_solver.solve(**solve_kwargs)
 
@@ -6208,6 +6243,7 @@ def test_log_config(self):
             " keepfiles=False\n"
             " tee=False\n"
             " load_solution=True\n"
+            " symbolic_solver_labels=False\n"
             " objective_focus=<ObjectiveType.nominal: 2>\n"
             " nominal_uncertain_param_vals=[0.5]\n"
             " decision_rule_order=0\n"
@@ -6302,5 +6338,598 @@ def test_log_disclaimer(self):
         )
 
 
+class UnavailableSolver:
+    def available(self, exception_flag=True):
+        if exception_flag:
+            raise ApplicationError(f"Solver {self.__class__} not available")
+        return False
+
+    def solve(self, model, *args, **kwargs):
+        return SolverResults()
+
+
+class TestPyROSUnavailableSubsolvers(unittest.TestCase):
+    """
+    Check that appropriate exceptionsa are raised if
+    PyROS is invoked with unavailable subsolvers.
+    """
+
+    def test_pyros_unavailable_subsolver(self):
+        """
+        Test PyROS raises expected error message when
+        unavailable subsolver is passed.
+        """
+        m = ConcreteModel()
+        m.p = Param(range(3), initialize=0, mutable=True)
+        m.z = Var([0, 1], initialize=0)
+        m.con = Constraint(expr=m.z[0] + m.z[1] >= m.p[0])
+        m.obj = Objective(expr=m.z[0] + m.z[1])
+
+        pyros_solver = SolverFactory("pyros")
+
+        exc_str = r".*Solver.*UnavailableSolver.*not available"
+        with self.assertRaisesRegex(ValueError, exc_str):
+            # note: ConfigDict interface raises ValueError
+            #       once any exception is triggered,
+            #       so we check for that instead of ApplicationError
+            with LoggingIntercept(level=logging.ERROR) as LOG:
+                pyros_solver.solve(
+                    model=m,
+                    first_stage_variables=[m.z[0]],
+                    second_stage_variables=[m.z[1]],
+                    uncertain_params=[m.p[0]],
+                    uncertainty_set=BoxSet([[0, 1]]),
+                    local_solver=SimpleTestSolver(),
+                    global_solver=UnavailableSolver(),
+                )
+
+        error_msgs = LOG.getvalue()[:-1]
+        self.assertRegex(
+            error_msgs, r"Output of `available\(\)` method.*global solver.*"
+        )
+
+    @unittest.skipUnless(ipopt_available, "IPOPT is not available.")
+    def test_pyros_unavailable_backup_subsolver(self):
+        """
+        Test PyROS raises expected error message when
+        unavailable backup subsolver is passed.
+        """
+        m = ConcreteModel()
+        m.p = Param(range(3), initialize=0, mutable=True)
+        m.z = Var([0, 1], initialize=0)
+        m.con = Constraint(expr=m.z[0] + m.z[1] >= m.p[0])
+        m.obj = Objective(expr=m.z[0] + m.z[1])
+
+        pyros_solver = SolverFactory("pyros")
+
+        # note: ConfigDict interface raises ValueError
+        #       once any exception is triggered,
+        #       so we check for that instead of ApplicationError
+        with LoggingIntercept(level=logging.WARNING) as LOG:
+            pyros_solver.solve(
+                model=m,
+                first_stage_variables=[m.z[0]],
+                second_stage_variables=[m.z[1]],
+                uncertain_params=[m.p[0]],
+                uncertainty_set=BoxSet([[0, 1]]),
+                local_solver=SolverFactory("ipopt"),
+                global_solver=SolverFactory("ipopt"),
+                backup_global_solvers=[UnavailableSolver()],
+                bypass_global_separation=True,
+            )
+
+        error_msgs = LOG.getvalue()[:-1]
+        self.assertRegex(
+            error_msgs,
+            r"Output of `available\(\)` method.*backup global solver.*"
+            r"Removing from list.*",
+        )
+
+
+class TestPyROSResolveKwargs(unittest.TestCase):
+    """
+    Test PyROS resolves kwargs as expected.
+    """
+
+    @unittest.skipUnless(ipopt_available, "IPOPT is not available.")
+    @unittest.skipUnless(
+        baron_license_is_valid, "Global NLP solver is not available and licensed."
+    )
+    def test_pyros_kwargs_with_overlap(self):
+        """
+        Test PyROS works as expected when there is overlap between
+        keyword arguments passed explicitly and implicitly
+        through `options`.
+        """
+        # define model
+        m = ConcreteModel()
+        m.x1 = Var(initialize=0, bounds=(0, None))
+        m.x2 = Var(initialize=0, bounds=(0, None))
+        m.x3 = Var(initialize=0, bounds=(None, None))
+        m.u1 = Param(initialize=1.125, mutable=True)
+        m.u2 = Param(initialize=1, mutable=True)
+
+        m.con1 = Constraint(expr=m.x1 * m.u1 ** (0.5) - m.x2 * m.u1 <= 2)
+        m.con2 = Constraint(expr=m.x1**2 - m.x2**2 * m.u1 == m.x3)
+
+        m.obj = Objective(expr=(m.x1 - 4) ** 2 + (m.x2 - m.u2) ** 2)
+
+        # Define the uncertainty set
+        # we take the parameter `u2` to be 'fixed'
+        ellipsoid = AxisAlignedEllipsoidalSet(center=[1.125, 1], half_lengths=[1, 0])
+
+        # Instantiate the PyROS solver
+        pyros_solver = SolverFactory("pyros")
+
+        # Define subsolvers utilized in the algorithm
+        local_subsolver = SolverFactory('ipopt')
+        global_subsolver = SolverFactory("baron")
+
+        # Call the PyROS solver
+        results = pyros_solver.solve(
+            model=m,
+            first_stage_variables=[m.x1, m.x2],
+            second_stage_variables=[],
+            uncertain_params=[m.u1, m.u2],
+            uncertainty_set=ellipsoid,
+            local_solver=local_subsolver,
+            global_solver=global_subsolver,
+            bypass_local_separation=True,
+            solve_master_globally=True,
+            options={
+                "objective_focus": ObjectiveType.worst_case,
+                "solve_master_globally": False,
+                "max_iter": 1,
+                "time_limit": 1000,
+            },
+        )
+
+        # check termination status as expected
+        self.assertEqual(
+            results.pyros_termination_condition,
+            pyrosTerminationCondition.max_iter,
+            msg="Termination condition not as expected",
+        )
+        self.assertEqual(
+            results.iterations, 1, msg="Number of iterations not as expected"
+        )
+
+        # check config resolved as expected
+        config = results.config
+        self.assertEqual(
+            config.bypass_local_separation,
+            True,
+            msg="Resolved value of kwarg `bypass_local_separation` not as expected.",
+        )
+        self.assertEqual(
+            config.solve_master_globally,
+            True,
+            msg="Resolved value of kwarg `solve_master_globally` not as expected.",
+        )
+        self.assertEqual(
+            config.max_iter,
+            1,
+            msg="Resolved value of kwarg `max_iter` not as expected.",
+        )
+        self.assertEqual(
+            config.objective_focus,
+            ObjectiveType.worst_case,
+            msg="Resolved value of kwarg `objective_focus` not as expected.",
+        )
+        self.assertEqual(
+            config.time_limit,
+            1e3,
+            msg="Resolved value of kwarg `time_limit` not as expected.",
+        )
+
+
+class SimpleTestSolver:
+    """
+    Simple test solver class with no actual solve()
+    functionality. Written to test unrelated aspects
+    of PyROS functionality.
+    """
+
+    def available(self, exception_flag=False):
+        """
+        Check solver available.
+        """
+        return True
+
+    def solve(self, model, **kwds):
+        """
+        Return SolverResults object with 'unknown' termination
+        condition. Model remains unchanged.
+        """
+        res = SolverResults()
+        res.solver.termination_condition = TerminationCondition.unknown
+
+        return res
+
+
+class TestPyROSSolverAdvancedValidation(unittest.TestCase):
+    """
+    Test PyROS solver returns expected exception messages
+    when arguments are invalid.
+    """
+
+    def build_simple_test_model(self):
+        """
+        Build simple valid test model.
+        """
+        m = ConcreteModel(name="test_model")
+
+        m.x1 = Var(initialize=0, bounds=(0, None))
+        m.x2 = Var(initialize=0, bounds=(0, None))
+        m.u = Param(initialize=1.125, mutable=True)
+
+        m.con1 = Constraint(expr=m.x1 * m.u ** (0.5) - m.x2 * m.u <= 2)
+
+        m.obj = Objective(expr=(m.x1 - 4) ** 2 + (m.x2 - 1) ** 2)
+
+        return m
+
+    def test_pyros_invalid_model_type(self):
+        """
+        Test PyROS fails if model is not of correct class.
+        """
+        mdl = self.build_simple_test_model()
+
+        local_solver = SimpleTestSolver()
+        global_solver = SimpleTestSolver()
+
+        pyros = SolverFactory("pyros")
+
+        exc_str = "Model should be of type.*but is of type.*"
+        with self.assertRaisesRegex(TypeError, exc_str):
+            pyros.solve(
+                model=2,
+                first_stage_variables=[mdl.x1],
+                second_stage_variables=[mdl.x2],
+                uncertain_params=[mdl.u],
+                uncertainty_set=BoxSet([[1 / 4, 2]]),
+                local_solver=local_solver,
+                global_solver=global_solver,
+            )
+
+    def test_pyros_multiple_objectives(self):
+        """
+        Test PyROS raises exception if input model has multiple
+        objectives.
+        """
+        mdl = self.build_simple_test_model()
+        mdl.obj2 = Objective(expr=(mdl.x1 + mdl.x2))
+
+        local_solver = SimpleTestSolver()
+        global_solver = SimpleTestSolver()
+
+        pyros = SolverFactory("pyros")
+
+        exc_str = "Expected model with exactly 1 active.*but.*has 2"
+        with self.assertRaisesRegex(ValueError, exc_str):
+            pyros.solve(
+                model=mdl,
+                first_stage_variables=[mdl.x1],
+                second_stage_variables=[mdl.x2],
+                uncertain_params=[mdl.u],
+                uncertainty_set=BoxSet([[1 / 4, 2]]),
+                local_solver=local_solver,
+                global_solver=global_solver,
+            )
+
+    def test_pyros_empty_dof_vars(self):
+        """
+        Test PyROS solver raises exception raised if there are no
+        first-stage variables or second-stage variables.
+        """
+        # build model
+        mdl = self.build_simple_test_model()
+
+        # prepare solvers
+        pyros = SolverFactory("pyros")
+        local_solver = SimpleTestSolver()
+        global_solver = SimpleTestSolver()
+
+        # perform checks
+        exc_str = (
+            "Arguments `first_stage_variables` and "
+            "`second_stage_variables` are both empty lists."
+        )
+        with self.assertRaisesRegex(ValueError, exc_str):
+            pyros.solve(
+                model=mdl,
+                first_stage_variables=[],
+                second_stage_variables=[],
+                uncertain_params=[mdl.u],
+                uncertainty_set=BoxSet([[1 / 4, 2]]),
+                local_solver=local_solver,
+                global_solver=global_solver,
+            )
+
+    def test_pyros_overlap_dof_vars(self):
+        """
+        Test PyROS solver raises exception raised if there are Vars
+        passed as both first-stage and second-stage.
+        """
+        # build model
+        mdl = self.build_simple_test_model()
+
+        # prepare solvers
+        pyros = SolverFactory("pyros")
+        local_solver = SimpleTestSolver()
+        global_solver = SimpleTestSolver()
+
+        # perform checks
+        exc_str = (
+            "Arguments `first_stage_variables` and `second_stage_variables` "
+            "contain at least one common Var object."
+        )
+        with LoggingIntercept(level=logging.ERROR) as LOG:
+            with self.assertRaisesRegex(ValueError, exc_str):
+                pyros.solve(
+                    model=mdl,
+                    first_stage_variables=[mdl.x1],
+                    second_stage_variables=[mdl.x1, mdl.x2],
+                    uncertain_params=[mdl.u],
+                    uncertainty_set=BoxSet([[1 / 4, 2]]),
+                    local_solver=local_solver,
+                    global_solver=global_solver,
+                )
+
+        # check logger output is as expected
+        log_msgs = LOG.getvalue().split("\n")[:-1]
+        self.assertEqual(
+            len(log_msgs), 3, "Error message does not contain expected number of lines."
+        )
+        self.assertRegex(
+            text=log_msgs[0],
+            expected_regex=(
+                "The following Vars were found in both `first_stage_variables`"
+                "and `second_stage_variables`.*"
+            ),
+        )
+        self.assertRegex(text=log_msgs[1], expected_regex=" 'x1'")
+        self.assertRegex(
+            text=log_msgs[2],
+            expected_regex="Ensure no Vars are included in both arguments.",
+        )
+
+    def test_pyros_vars_not_in_model(self):
+        """
+        Test PyROS appropriately raises exception if there are
+        variables not included in active model objective
+        or constraints which are not descended from model.
+        """
+        # set up model
+        mdl = self.build_simple_test_model()
+        mdl.name = "model1"
+        mdl2 = self.build_simple_test_model()
+        mdl2.name = "model2"
+
+        # set up solvers
+        local_solver = SimpleTestSolver()
+        global_solver = SimpleTestSolver()
+        pyros = SolverFactory("pyros")
+
+        mdl.bad_con = Constraint(expr=mdl2.x1 + mdl2.x2 >= 1)
+
+        desc_dof_map = [
+            ("first-stage", [mdl2.x1], [], 2),
+            ("second-stage", [], [mdl2.x2], 2),
+            ("state", [mdl.x1], [], 3),
+        ]
+
+        # now perform checks
+        for vardesc, first_stage_vars, second_stage_vars, numlines in desc_dof_map:
+            with LoggingIntercept(level=logging.ERROR) as LOG:
+                exc_str = (
+                    "Found entries of "
+                    f"{vardesc} variables not descended from.*model.*"
+                )
+                with self.assertRaisesRegex(ValueError, exc_str):
+                    pyros.solve(
+                        model=mdl,
+                        first_stage_variables=first_stage_vars,
+                        second_stage_variables=second_stage_vars,
+                        uncertain_params=[mdl.u],
+                        uncertainty_set=BoxSet([[1 / 4, 2]]),
+                        local_solver=local_solver,
+                        global_solver=global_solver,
+                    )
+
+            log_msgs = LOG.getvalue().split("\n")[:-1]
+
+            # check detailed log message is as expected
+            self.assertEqual(
+                len(log_msgs),
+                numlines,
+                "Error-level log message does not contain expected number of lines.",
+            )
+            self.assertRegex(
+                text=log_msgs[0],
+                expected_regex=(
+                    f"The following {vardesc} variables"
+                    ".*not descended from.*model with name 'model1'"
+                ),
+            )
+
+    def test_pyros_non_continuous_vars(self):
+        """
+        Test PyROS raises exception if model contains
+        non-continuous variables.
+        """
+        # build model; make one variable discrete
+        mdl = self.build_simple_test_model()
+        mdl.x2.domain = NonNegativeIntegers
+
+        # prepare solvers
+        pyros = SolverFactory("pyros")
+        local_solver = SimpleTestSolver()
+        global_solver = SimpleTestSolver()
+
+        # perform checks
+        exc_str = "Model with name 'test_model' contains non-continuous Vars."
+        with LoggingIntercept(level=logging.ERROR) as LOG:
+            with self.assertRaisesRegex(ValueError, exc_str):
+                pyros.solve(
+                    model=mdl,
+                    first_stage_variables=[mdl.x1],
+                    second_stage_variables=[mdl.x2],
+                    uncertain_params=[mdl.u],
+                    uncertainty_set=BoxSet([[1 / 4, 2]]),
+                    local_solver=local_solver,
+                    global_solver=global_solver,
+                )
+
+        # check logger output is as expected
+        log_msgs = LOG.getvalue().split("\n")[:-1]
+        self.assertEqual(
+            len(log_msgs), 3, "Error message does not contain expected number of lines."
+        )
+        self.assertRegex(
+            text=log_msgs[0],
+            expected_regex=(
+                "The following Vars of model with name 'test_model' "
+                "are non-continuous:"
+            ),
+        )
+        self.assertRegex(text=log_msgs[1], expected_regex=" 'x2'")
+        self.assertRegex(
+            text=log_msgs[2],
+            expected_regex=(
+                "Ensure all model variables passed to " "PyROS solver are continuous."
+            ),
+        )
+
+    def test_pyros_uncertainty_dimension_mismatch(self):
+        """
+        Test PyROS solver raises exception if uncertainty
+        set dimension does not match the number
+        of uncertain parameters.
+        """
+        # build model
+        mdl = self.build_simple_test_model()
+
+        # prepare solvers
+        pyros = SolverFactory("pyros")
+        local_solver = SimpleTestSolver()
+        global_solver = SimpleTestSolver()
+
+        # perform checks
+        exc_str = (
+            r"Length of argument `uncertain_params` does not match dimension "
+            r"of argument `uncertainty_set` \(1 != 2\)."
+        )
+        with self.assertRaisesRegex(ValueError, exc_str):
+            pyros.solve(
+                model=mdl,
+                first_stage_variables=[mdl.x1],
+                second_stage_variables=[mdl.x2],
+                uncertain_params=[mdl.u],
+                uncertainty_set=BoxSet([[1 / 4, 2], [0, 1]]),
+                local_solver=local_solver,
+                global_solver=global_solver,
+            )
+
+    @unittest.skipUnless(ipopt_available, "IPOPT is not available.")
+    def test_pyros_nominal_point_not_in_set(self):
+        """
+        Test PyROS raises exception if nominal point is not in the
+        uncertainty set.
+
+        NOTE: need executable solvers to solve set bounding problems
+              for validity checks.
+        """
+        # build model
+        mdl = self.build_simple_test_model()
+
+        # prepare solvers
+        pyros = SolverFactory("pyros")
+        local_solver = SolverFactory("ipopt")
+        global_solver = SolverFactory("ipopt")
+
+        # perform checks
+        exc_str = (
+            r"Nominal uncertain parameter realization \[0\] "
+            "is not a point in the uncertainty set.*"
+        )
+        with self.assertRaisesRegex(ValueError, exc_str):
+            pyros.solve(
+                model=mdl,
+                first_stage_variables=[mdl.x1],
+                second_stage_variables=[mdl.x2],
+                uncertain_params=[mdl.u],
+                uncertainty_set=BoxSet([[1 / 4, 2]]),
+                local_solver=local_solver,
+                global_solver=global_solver,
+                nominal_uncertain_param_vals=[0],
+            )
+
+    @unittest.skipUnless(ipopt_available, "IPOPT is not available.")
+    def test_pyros_nominal_point_len_mismatch(self):
+        """
+        Test PyROS raises exception if there is mismatch between length
+        of nominal uncertain parameter specification and number
+        of uncertain parameters.
+        """
+        # build model
+        mdl = self.build_simple_test_model()
+
+        # prepare solvers
+        pyros = SolverFactory("pyros")
+        local_solver = SolverFactory("ipopt")
+        global_solver = SolverFactory("ipopt")
+
+        # perform checks
+        exc_str = (
+            r"Lengths of arguments `uncertain_params` "
+            r"and `nominal_uncertain_param_vals` "
+            r"do not match \(1 != 2\)."
+        )
+        with self.assertRaisesRegex(ValueError, exc_str):
+            pyros.solve(
+                model=mdl,
+                first_stage_variables=[mdl.x1],
+                second_stage_variables=[mdl.x2],
+                uncertain_params=[mdl.u],
+                uncertainty_set=BoxSet([[1 / 4, 2]]),
+                local_solver=local_solver,
+                global_solver=global_solver,
+                nominal_uncertain_param_vals=[0, 1],
+            )
+
+    @unittest.skipUnless(ipopt_available, "IPOPT is not available.")
+    def test_pyros_invalid_bypass_separation(self):
+        """
+        Test PyROS raises exception if both local and
+        global separation are set to be bypassed.
+        """
+        # build model
+        mdl = self.build_simple_test_model()
+
+        # prepare solvers
+        pyros = SolverFactory("pyros")
+        local_solver = SolverFactory("ipopt")
+        global_solver = SolverFactory("ipopt")
+
+        # perform checks
+        exc_str = (
+            r"Arguments `bypass_local_separation` and `bypass_global_separation` "
+            r"cannot both be True."
+        )
+        with self.assertRaisesRegex(ValueError, exc_str):
+            pyros.solve(
+                model=mdl,
+                first_stage_variables=[mdl.x1],
+                second_stage_variables=[mdl.x2],
+                uncertain_params=[mdl.u],
+                uncertainty_set=BoxSet([[1 / 4, 2]]),
+                local_solver=local_solver,
+                global_solver=global_solver,
+                bypass_local_separation=True,
+                bypass_global_separation=True,
+            )
+
+
 if __name__ == "__main__":
     unittest.main()
diff --git a/pyomo/contrib/pyros/uncertainty_sets.py b/pyomo/contrib/pyros/uncertainty_sets.py
index 1b51e41fcaf..028a9f38da1 100644
--- a/pyomo/contrib/pyros/uncertainty_sets.py
+++ b/pyomo/contrib/pyros/uncertainty_sets.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """
 Abstract and pre-defined classes for representing uncertainty sets (or
 uncertain parameter spaces) of two-stage nonlinear robust optimization
@@ -272,14 +283,6 @@ def generate_shape_str(shape, required_shape):
         )
 
 
-def uncertainty_sets(obj):
-    if not isinstance(obj, UncertaintySet):
-        raise ValueError(
-            "Expected an UncertaintySet object, instead received %s" % (obj,)
-        )
-    return obj
-
-
 def column(matrix, i):
     # Get column i of a given multi-dimensional list
     return [row[i] for row in matrix]
diff --git a/pyomo/contrib/pyros/util.py b/pyomo/contrib/pyros/util.py
index e2986ae18c7..ecabca8f115 100644
--- a/pyomo/contrib/pyros/util.py
+++ b/pyomo/contrib/pyros/util.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 '''
 Utility functions for the PyROS solver
 '''
@@ -5,7 +16,9 @@
 import copy
 from enum import Enum, auto
 from pyomo.common.collections import ComponentSet, ComponentMap
+from pyomo.common.errors import ApplicationError
 from pyomo.common.modeling import unique_component_name
+from pyomo.common.timing import TicTocTimer
 from pyomo.core.base import (
     Constraint,
     Var,
@@ -25,6 +38,7 @@
 from pyomo.core.expr import value
 from pyomo.core.expr.numeric_expr import NPV_MaxExpression, NPV_MinExpression
 from pyomo.repn.standard_repn import generate_standard_repn
+from pyomo.repn.plugins import nl_writer as pyomo_nl_writer
 from pyomo.core.expr.visitor import (
     identify_variables,
     identify_mutable_parameters,
@@ -219,15 +233,15 @@ def get_main_elapsed_time(timing_data_obj):
 
 def adjust_solver_time_settings(timing_data_obj, solver, config):
     """
-    Adjust solver max time setting based on current PyROS elapsed
-    time.
+    Adjust maximum time allowed for subordinate solver, based
+    on total PyROS solver elapsed time up to this point.
 
     Parameters
     ----------
     timing_data_obj : Bunch
         PyROS timekeeper.
     solver : solver type
-        Solver for which to adjust the max time setting.
+        Subordinate solver for which to adjust the max time setting.
     config : ConfigDict
         PyROS solver config.
 
@@ -249,26 +263,37 @@ def adjust_solver_time_settings(timing_data_obj, solver, config):
     ----
     (1) Adjustment only supported for GAMS, BARON, and IPOPT
         interfaces. This routine can be generalized to other solvers
-        after a generic interface to the time limit setting
+        after a generic Pyomo interface to the time limit setting
         is introduced.
-    (2) For IPOPT, and probably also BARON, the CPU time limit
-        rather than the wallclock time limit, is adjusted, as
-        no interface to wallclock limit available.
-        For this reason, extra 30s is added to time remaining
-        for subsolver time limit.
-        (The extra 30s is large enough to ensure solver
-        elapsed time is not beneath elapsed time - user time limit,
-        but not so large as to overshoot the user-specified time limit
-        by an inordinate margin.)
+    (2) For IPOPT and BARON, the CPU time limit,
+        rather than the wallclock time limit, may be adjusted,
+        as there may be no means by which to specify the wall time
+        limit explicitly.
+    (3) For GAMS, we adjust the time limit through the GAMS Reslim
+        option. However, this may be overridden by any user
+        specifications included in a GAMS optfile, which may be
+        difficult to track down.
+    (4) To ensure the time limit is specified to a strictly
+        positive value, the time limit is adjusted to a value of
+        at least 1 second.
     """
+    # in case there is no time remaining: we set time limit
+    # to a minimum of 1s, as some solvers require a strictly
+    # positive time limit
+    time_limit_buffer = 1
+
     if config.time_limit is not None:
         time_remaining = config.time_limit - get_main_elapsed_time(timing_data_obj)
         if isinstance(solver, type(SolverFactory("gams", solver_io="shell"))):
             original_max_time_setting = solver.options["add_options"]
             custom_setting_present = "add_options" in solver.options
 
-            # adjust GAMS solver time
-            reslim_str = f"option reslim={max(30, 30 + time_remaining)};"
+            # note: our time limit will be overridden by any
+            #       time limits specified by the user through a
+            #       GAMS optfile, but tracking down the optfile
+            #       and/or the GAMS subsolver specific option
+            #       is more difficult
+            reslim_str = "option reslim=" f"{max(time_limit_buffer, time_remaining)};"
             if isinstance(solver.options["add_options"], list):
                 solver.options["add_options"].append(reslim_str)
             else:
@@ -278,7 +303,16 @@ def adjust_solver_time_settings(timing_data_obj, solver, config):
             if isinstance(solver, SolverFactory.get_class("baron")):
                 options_key = "MaxTime"
             elif isinstance(solver, SolverFactory.get_class("ipopt")):
-                options_key = "max_cpu_time"
+                options_key = (
+                    # IPOPT 3.14.0+ added support for specifying
+                    # wall time limit explicitly; this is preferred
+                    # over CPU time limit
+                    "max_wall_time"
+                    if solver.version() >= (3, 14, 0, 0)
+                    else "max_cpu_time"
+                )
+            elif isinstance(solver, SolverFactory.get_class("scip")):
+                options_key = "limits/time"
             else:
                 options_key = None
 
@@ -286,8 +320,19 @@ def adjust_solver_time_settings(timing_data_obj, solver, config):
                 custom_setting_present = options_key in solver.options
                 original_max_time_setting = solver.options[options_key]
 
-                # ensure positive value assigned to avoid application error
-                solver.options[options_key] = max(30, 30 + time_remaining)
+                # account for elapsed time remaining and
+                # original time limit setting.
+                # if no original time limit is set, then we assume
+                # there is no time limit, rather than tracking
+                # down the solver-specific default
+                orig_max_time = (
+                    float("inf")
+                    if original_max_time_setting is None
+                    else original_max_time_setting
+                )
+                solver.options[options_key] = min(
+                    max(time_limit_buffer, time_remaining), orig_max_time
+                )
             else:
                 custom_setting_present = False
                 original_max_time_setting = None
@@ -333,7 +378,16 @@ def revert_solver_max_time_adjustment(
         elif isinstance(solver, SolverFactory.get_class("baron")):
             options_key = "MaxTime"
         elif isinstance(solver, SolverFactory.get_class("ipopt")):
-            options_key = "max_cpu_time"
+            options_key = (
+                # IPOPT 3.14.0+ added support for specifying
+                # wall time limit explicitly; this is preferred
+                # over CPU time limit
+                "max_wall_time"
+                if solver.version() >= (3, 14, 0, 0)
+                else "max_cpu_time"
+            )
+        elif isinstance(solver, SolverFactory.get_class("scip")):
+            options_key = "limits/time"
         else:
             options_key = None
 
@@ -348,12 +402,7 @@ def revert_solver_max_time_adjustment(
                 if isinstance(solver, type(SolverFactory("gams", solver_io="shell"))):
                     solver.options[options_key].pop()
             else:
-                # remove the max time specification introduced.
-                # All lines are needed here to completely remove the option
-                # from access through getattr and dictionary reference.
                 delattr(solver.options, options_key)
-                if options_key in solver.options.keys():
-                    del solver.options[options_key]
 
 
 class PreformattedLogger(logging.Logger):
@@ -434,51 +483,6 @@ def setup_pyros_logger(name=DEFAULT_LOGGER_NAME):
     return logger
 
 
-def a_logger(str_or_logger):
-    """
-    Standardize a string or logger object to a logger object.
-
-    Parameters
-    ----------
-    str_or_logger : str or logging.Logger
-        String or logger object to normalize.
-
-    Returns
-    -------
-    logging.Logger
-        If `str_or_logger` is of type `logging.Logger`,then
-        `str_or_logger` is returned.
-        Otherwise, ``logging.getLogger(str_or_logger)``
-        is returned. In the event `str_or_logger` is
-        the name of the default PyROS logger, the logger level
-        is set to `logging.INFO`, and a `PreformattedLogger`
-        instance is returned in lieu of a standard `Logger`
-        instance.
-    """
-    if isinstance(str_or_logger, logging.Logger):
-        return logging.getLogger(str_or_logger.name)
-    else:
-        return logging.getLogger(str_or_logger)
-
-
-def ValidEnum(enum_class):
-    '''
-    Python 3 dependent format string
-    '''
-
-    def fcn(obj):
-        if obj not in enum_class:
-            raise ValueError(
-                "Expected an {0} object, "
-                "instead received {1}".format(
-                    enum_class.__name__, obj.__class__.__name__
-                )
-            )
-        return obj
-
-    return fcn
-
-
 class pyrosTerminationCondition(Enum):
     """Enumeration of all possible PyROS termination conditions."""
 
@@ -557,14 +561,6 @@ def recast_to_min_obj(model, obj):
         obj.sense = minimize
 
 
-def model_is_valid(model):
-    """
-    Assess whether model is valid on basis of the number of active
-    Objectives. A valid model must contain exactly one active Objective.
-    """
-    return len(list(model.component_data_objects(Objective, active=True))) == 1
-
-
 def turn_bounds_to_constraints(variable, model, config=None):
     '''
     Turn the variable in question's "bounds" into direct inequality constraints on the model.
@@ -648,41 +644,6 @@ def get_time_from_solver(results):
     return float("nan") if solve_time is None else solve_time
 
 
-def validate_uncertainty_set(config):
-    '''
-    Confirm expression output from uncertainty set function references all q in q.
-    Typecheck the uncertainty_set.q is Params referenced inside of m.
-    Give warning that the nominal point (default value in the model) is not in the specified uncertainty set.
-    :param config: solver config
-    '''
-    # === Check that q in UncertaintySet object constraint expression is referencing q in model.uncertain_params
-    uncertain_params = config.uncertain_params
-
-    # === Non-zero number of uncertain parameters
-    if len(uncertain_params) == 0:
-        raise AttributeError(
-            "Must provide uncertain params, uncertain_params list length is 0."
-        )
-    # === No duplicate parameters
-    if len(uncertain_params) != len(ComponentSet(uncertain_params)):
-        raise AttributeError("No duplicates allowed for uncertain param objects.")
-    # === Ensure nominal point is in the set
-    if not config.uncertainty_set.point_in_set(
-        point=config.nominal_uncertain_param_vals
-    ):
-        raise AttributeError(
-            "Nominal point for uncertain parameters must be in the uncertainty set."
-        )
-    # === Check set validity via boundedness and non-emptiness
-    if not config.uncertainty_set.is_valid(config=config):
-        raise AttributeError(
-            "Invalid uncertainty set detected. Check the uncertainty set object to "
-            "ensure non-emptiness and boundedness."
-        )
-
-    return
-
-
 def add_bounds_for_uncertain_parameters(model, config):
     '''
     This function solves a set of optimization problems to determine bounds on the uncertain parameters
@@ -862,98 +823,345 @@ def replace_uncertain_bounds_with_constraints(model, uncertain_params):
             v.setlb(None)
 
 
-def validate_kwarg_inputs(model, config):
-    '''
-    Confirm kwarg inputs satisfy PyROS requirements.
-    :param model: the deterministic model
-    :param config: the config for this PyROS instance
-    :return:
-    '''
-
-    # === Check if model is ConcreteModel object
-    if not isinstance(model, ConcreteModel):
-        raise ValueError("Model passed to PyROS solver must be a ConcreteModel object.")
+def check_components_descended_from_model(model, components, components_name, config):
+    """
+    Check all members in a provided sequence of Pyomo component
+    objects are descended from a given ConcreteModel object.
 
-    first_stage_variables = config.first_stage_variables
-    second_stage_variables = config.second_stage_variables
-    uncertain_params = config.uncertain_params
+    Parameters
+    ----------
+    model : ConcreteModel
+        Model from which components should all be descended.
+    components : Iterable of Component
+        Components of interest.
+    components_name : str
+        Brief description or name for the sequence of components.
+        Used for constructing error messages.
+    config : ConfigDict
+        PyROS solver options.
 
-    if not config.first_stage_variables and not config.second_stage_variables:
-        # Must have non-zero DOF
+    Raises
+    ------
+    ValueError
+        If at least one entry of `components` is not descended
+        from `model`.
+    """
+    components_not_in_model = [comp for comp in components if comp.model() is not model]
+    if components_not_in_model:
+        comp_names_str = "\n ".join(
+            f"{comp.name!r}, from model with name {comp.model().name!r}"
+            for comp in components_not_in_model
+        )
+        config.progress_logger.error(
+            f"The following {components_name} "
+            "are not descended from the "
+            f"input deterministic model with name {model.name!r}:\n "
+            f"{comp_names_str}"
+        )
         raise ValueError(
-            "first_stage_variables and "
-            "second_stage_variables cannot both be empty lists."
+            f"Found entries of {components_name} "
+            "not descended from input model. "
+            "Check logger output messages."
         )
 
-    if ComponentSet(first_stage_variables) != ComponentSet(
-        config.first_stage_variables
-    ):
+
+def get_state_vars(blk, first_stage_variables, second_stage_variables):
+    """
+    Get state variables of a modeling block.
+
+    The state variables with respect to `blk` are the unfixed
+    `VarData` objects participating in the active objective
+    or constraints descended from `blk` which are not
+    first-stage variables or second-stage variables.
+
+    Parameters
+    ----------
+    blk : ScalarBlock
+        Block of interest.
+    first_stage_variables : Iterable of VarData
+        First-stage variables.
+    second_stage_variables : Iterable of VarData
+        Second-stage variables.
+
+    Yields
+    ------
+    VarData
+        State variable.
+    """
+    dof_var_set = ComponentSet(first_stage_variables) | ComponentSet(
+        second_stage_variables
+    )
+    for var in get_vars_from_component(blk, (Objective, Constraint)):
+        is_state_var = not var.fixed and var not in dof_var_set
+        if is_state_var:
+            yield var
+
+
+def check_variables_continuous(model, vars, config):
+    """
+    Check that all DOF and state variables of the model
+    are continuous.
+
+    Parameters
+    ----------
+    model : ConcreteModel
+        Input deterministic model.
+    config : ConfigDict
+        PyROS solver options.
+
+    Raises
+    ------
+    ValueError
+        If at least one variable is found to not be continuous.
+
+    Note
+    ----
+    A variable is considered continuous if the `is_continuous()`
+    method returns True.
+    """
+    non_continuous_vars = [var for var in vars if not var.is_continuous()]
+    if non_continuous_vars:
+        non_continuous_vars_str = "\n ".join(
+            f"{var.name!r}" for var in non_continuous_vars
+        )
+        config.progress_logger.error(
+            f"The following Vars of model with name {model.name!r} "
+            f"are non-continuous:\n {non_continuous_vars_str}\n"
+            "Ensure all model variables passed to PyROS solver are continuous."
+        )
         raise ValueError(
-            "All elements in first_stage_variables must be Var members of the model object."
+            f"Model with name {model.name!r} contains non-continuous Vars."
         )
 
-    if ComponentSet(second_stage_variables) != ComponentSet(
-        config.second_stage_variables
-    ):
+
+def validate_model(model, config):
+    """
+    Validate deterministic model passed to PyROS solver.
+
+    Parameters
+    ----------
+    model : ConcreteModel
+        Deterministic model. Should have only one active Objective.
+    config : ConfigDict
+        PyROS solver options.
+
+    Returns
+    -------
+    ComponentSet
+        The variables participating in the active Objective
+        and Constraint expressions of `model`.
+
+    Raises
+    ------
+    TypeError
+        If model is not of type ConcreteModel.
+    ValueError
+        If model does not have exactly one active Objective
+        component.
+    """
+    # note: only support ConcreteModel. no support for Blocks
+    if not isinstance(model, ConcreteModel):
+        raise TypeError(
+            f"Model should be of type {ConcreteModel.__name__}, "
+            f"but is of type {type(model).__name__}."
+        )
+
+    # active objectives check
+    active_objs_list = list(
+        model.component_data_objects(Objective, active=True, descend_into=True)
+    )
+    if len(active_objs_list) != 1:
         raise ValueError(
-            "All elements in second_stage_variables must be Var members of the model object."
+            "Expected model with exactly 1 active objective, but "
+            f"model provided has {len(active_objs_list)}."
         )
 
-    if any(
-        v in ComponentSet(second_stage_variables)
-        for v in ComponentSet(first_stage_variables)
-    ):
+
+def validate_variable_partitioning(model, config):
+    """
+    Check that partitioning of the first-stage variables,
+    second-stage variables, and uncertain parameters
+    is valid.
+
+    Parameters
+    ----------
+    model : ConcreteModel
+        Input deterministic model.
+    config : ConfigDict
+        PyROS solver options.
+
+    Returns
+    -------
+    list of VarData
+        State variables of the model.
+
+    Raises
+    ------
+    ValueError
+        If first-stage variables and second-stage variables
+        overlap, or there are no first-stage variables
+        and no second-stage variables.
+    """
+    # at least one DOF required
+    if not config.first_stage_variables and not config.second_stage_variables:
         raise ValueError(
-            "No common elements allowed between first_stage_variables and second_stage_variables."
+            "Arguments `first_stage_variables` and "
+            "`second_stage_variables` are both empty lists."
         )
 
-    if ComponentSet(uncertain_params) != ComponentSet(config.uncertain_params):
+    # ensure no overlap between DOF var sets
+    overlapping_vars = ComponentSet(config.first_stage_variables) & ComponentSet(
+        config.second_stage_variables
+    )
+    if overlapping_vars:
+        overlapping_var_list = "\n ".join(f"{var.name!r}" for var in overlapping_vars)
+        config.progress_logger.error(
+            "The following Vars were found in both `first_stage_variables`"
+            f"and `second_stage_variables`:\n {overlapping_var_list}"
+            "\nEnsure no Vars are included in both arguments."
+        )
         raise ValueError(
-            "uncertain_params must be mutable Param members of the model object."
+            "Arguments `first_stage_variables` and `second_stage_variables` "
+            "contain at least one common Var object."
         )
 
-    if not config.uncertainty_set:
+    state_vars = list(
+        get_state_vars(
+            model,
+            first_stage_variables=config.first_stage_variables,
+            second_stage_variables=config.second_stage_variables,
+        )
+    )
+    var_type_list_map = {
+        "first-stage variables": config.first_stage_variables,
+        "second-stage variables": config.second_stage_variables,
+        "state variables": state_vars,
+    }
+    for desc, vars in var_type_list_map.items():
+        check_components_descended_from_model(
+            model=model, components=vars, components_name=desc, config=config
+        )
+
+    all_vars = config.first_stage_variables + config.second_stage_variables + state_vars
+    check_variables_continuous(model, all_vars, config)
+
+    return state_vars
+
+
+def validate_uncertainty_specification(model, config):
+    """
+    Validate specification of uncertain parameters and uncertainty
+    set.
+
+    Parameters
+    ----------
+    model : ConcreteModel
+        Input deterministic model.
+    config : ConfigDict
+        PyROS solver options.
+
+    Raises
+    ------
+    ValueError
+        If at least one of the following holds:
+
+        - dimension of uncertainty set does not equal number of
+          uncertain parameters
+        - uncertainty set `is_valid()` method does not return
+          true.
+        - nominal parameter realization is not in the uncertainty set.
+    """
+    check_components_descended_from_model(
+        model=model,
+        components=config.uncertain_params,
+        components_name="uncertain parameters",
+        config=config,
+    )
+
+    if len(config.uncertain_params) != config.uncertainty_set.dim:
         raise ValueError(
-            "An UncertaintySet object must be provided to the PyROS solver."
+            "Length of argument `uncertain_params` does not match dimension "
+            "of argument `uncertainty_set` "
+            f"({len(config.uncertain_params)} != {config.uncertainty_set.dim})."
         )
 
-    non_mutable_params = []
-    for p in config.uncertain_params:
-        if not (
-            not p.is_constant() and p.is_fixed() and not p.is_potentially_variable()
-        ):
-            non_mutable_params.append(p)
-        if non_mutable_params:
-            raise ValueError(
-                "Param objects which are uncertain must have attribute mutable=True. "
-                "Offending Params: %s" % [p.name for p in non_mutable_params]
-            )
+    # validate uncertainty set
+    if not config.uncertainty_set.is_valid(config=config):
+        raise ValueError(
+            f"Uncertainty set {config.uncertainty_set} is invalid, "
+            "as it is either empty or unbounded."
+        )
 
-    # === Solvers provided check
-    if not config.local_solver or not config.global_solver:
+    # fill-in nominal point as necessary, if not provided.
+    # otherwise, check length matches uncertainty dimension
+    if not config.nominal_uncertain_param_vals:
+        config.nominal_uncertain_param_vals = [
+            value(param, exception=True) for param in config.uncertain_params
+        ]
+    elif len(config.nominal_uncertain_param_vals) != len(config.uncertain_params):
         raise ValueError(
-            "User must designate both a local and global optimization solver via the local_solver"
-            " and global_solver options."
+            "Lengths of arguments `uncertain_params` and "
+            "`nominal_uncertain_param_vals` "
+            "do not match "
+            f"({len(config.uncertain_params)} != "
+            f"{len(config.nominal_uncertain_param_vals)})."
         )
 
-    if config.bypass_local_separation and config.bypass_global_separation:
+    # uncertainty set should contain nominal point
+    nominal_point_in_set = config.uncertainty_set.point_in_set(
+        point=config.nominal_uncertain_param_vals
+    )
+    if not nominal_point_in_set:
         raise ValueError(
-            "User cannot simultaneously enable options "
-            "'bypass_local_separation' and "
-            "'bypass_global_separation'."
+            "Nominal uncertain parameter realization "
+            f"{config.nominal_uncertain_param_vals} "
+            "is not a point in the uncertainty set "
+            f"{config.uncertainty_set!r}."
         )
 
-    # === Degrees of freedom provided check
-    if len(config.first_stage_variables) + len(config.second_stage_variables) == 0:
+
+def validate_separation_problem_options(model, config):
+    """
+    Validate separation problem arguments to the PyROS solver.
+
+    Parameters
+    ----------
+    model : ConcreteModel
+        Input deterministic model.
+    config : ConfigDict
+        PyROS solver options.
+
+    Raises
+    ------
+    ValueError
+        If options `bypass_local_separation` and
+        `bypass_global_separation` are set to False.
+    """
+    if config.bypass_local_separation and config.bypass_global_separation:
         raise ValueError(
-            "User must designate at least one first- and/or second-stage variable."
+            "Arguments `bypass_local_separation` "
+            "and `bypass_global_separation` "
+            "cannot both be True."
         )
 
-    # === Uncertain params provided check
-    if len(config.uncertain_params) == 0:
-        raise ValueError("User must designate at least one uncertain parameter.")
 
-    return
+def validate_pyros_inputs(model, config):
+    """
+    Perform advanced validation of PyROS solver arguments.
+
+    Parameters
+    ----------
+    model : ConcreteModel
+        Input deterministic model.
+    config : ConfigDict
+        PyROS solver options.
+    """
+    validate_model(model, config)
+    state_vars = validate_variable_partitioning(model, config)
+    validate_uncertainty_specification(model, config)
+    validate_separation_problem_options(model, config)
+
+    return state_vars
 
 
 def substitute_ssv_in_dr_constraints(model, constraint):
@@ -1561,6 +1769,92 @@ def process_termination_condition_master_problem(config, results):
             )
 
 
+def call_solver(model, solver, config, timing_obj, timer_name, err_msg):
+    """
+    Solve a model with a given optimizer, keeping track of
+    wall time requirements.
+
+    Parameters
+    ----------
+    model : ConcreteModel
+        Model of interest.
+    solver : Pyomo solver type
+        Subordinate optimizer.
+    config : ConfigDict
+        PyROS solver settings.
+    timing_obj : TimingData
+        PyROS solver timing data object.
+    timer_name : str
+        Name of sub timer under the hierarchical timer contained in
+        ``timing_obj`` to start/stop for keeping track of solve
+        time requirements.
+    err_msg : str
+        Message to log through ``config.progress_logger.exception()``
+        in event an ApplicationError is raised while attempting to
+        solve the model.
+
+    Returns
+    -------
+    SolverResults
+        Solve results. Note that ``results.solver`` contains
+        an additional attribute, named after
+        ``TIC_TOC_SOLVE_TIME_ATTR``, of which the value is set to the
+        recorded solver wall time.
+
+    Raises
+    ------
+    ApplicationError
+        If ApplicationError is raised by the solver.
+        In this case, `err_msg` is logged through
+        ``config.progress_logger.exception()`` before
+        the exception is raised.
+    """
+    tt_timer = TicTocTimer()
+
+    orig_setting, custom_setting_present = adjust_solver_time_settings(
+        timing_obj, solver, config
+    )
+    timing_obj.start_timer(timer_name)
+    tt_timer.tic(msg=None)
+
+    # tentative: reduce risk of InfeasibleConstraintException
+    # occurring due to discrepancies between Pyomo NL writer
+    # tolerance and (default) subordinate solver (e.g. IPOPT)
+    # feasibility tolerances.
+    # e.g., a Var fixed outside bounds beyond the Pyomo NL writer
+    # tolerance, but still within the default IPOPT feasibility
+    # tolerance
+    current_nl_writer_tol = pyomo_nl_writer.TOL
+    pyomo_nl_writer.TOL = 1e-4
+
+    try:
+        results = solver.solve(
+            model,
+            tee=config.tee,
+            load_solutions=False,
+            symbolic_solver_labels=config.symbolic_solver_labels,
+        )
+    except ApplicationError:
+        # account for possible external subsolver errors
+        # (such as segmentation faults, function evaluation
+        # errors, etc.)
+        config.progress_logger.error(err_msg)
+        raise
+    else:
+        setattr(
+            results.solver, TIC_TOC_SOLVE_TIME_ATTR, tt_timer.toc(msg=None, delta=True)
+        )
+    finally:
+        pyomo_nl_writer.TOL = current_nl_writer_tol
+
+        timing_obj.stop_timer(timer_name)
+        revert_solver_max_time_adjustment(
+            solver, orig_setting, custom_setting_present, config
+        )
+
+    return results
+
+
 class IterationLogRecord:
     """
     PyROS solver iteration log record.
diff --git a/pyomo/contrib/satsolver/__init__.py b/pyomo/contrib/satsolver/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/satsolver/__init__.py
+++ b/pyomo/contrib/satsolver/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/satsolver/satsolver.py b/pyomo/contrib/satsolver/satsolver.py
index 139b5218169..b5004d6a611 100644
--- a/pyomo/contrib/satsolver/satsolver.py
+++ b/pyomo/contrib/satsolver/satsolver.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import math
 
 from pyomo.common.dependencies import attempt_import
diff --git a/pyomo/contrib/satsolver/test_satsolver.py b/pyomo/contrib/satsolver/test_satsolver.py
index 7ac7aaff03f..f19f172f7b2 100644
--- a/pyomo/contrib/satsolver/test_satsolver.py
+++ b/pyomo/contrib/satsolver/test_satsolver.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/sensitivity_toolbox/__init__.py b/pyomo/contrib/sensitivity_toolbox/__init__.py
index cac6562157e..a20cbc389d7 100644
--- a/pyomo/contrib/sensitivity_toolbox/__init__.py
+++ b/pyomo/contrib/sensitivity_toolbox/__init__.py
@@ -1,7 +1,18 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # ___________________________________________________________________________
 #
 # Pyomo: Python Optimization Modeling Objects
-# Copyright (c) 2008-2022
+# Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 # Under the terms of Contract DE-NA0003525 with National Technology and
 # Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/sensitivity_toolbox/examples/HIV_Transmission.py b/pyomo/contrib/sensitivity_toolbox/examples/HIV_Transmission.py
index 2c8996c95ca..8d43dea26b2 100755
--- a/pyomo/contrib/sensitivity_toolbox/examples/HIV_Transmission.py
+++ b/pyomo/contrib/sensitivity_toolbox/examples/HIV_Transmission.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/sensitivity_toolbox/examples/__init__.py b/pyomo/contrib/sensitivity_toolbox/examples/__init__.py
index 5223f39bbc1..a408b878891 100644
--- a/pyomo/contrib/sensitivity_toolbox/examples/__init__.py
+++ b/pyomo/contrib/sensitivity_toolbox/examples/__init__.py
@@ -1,7 +1,18 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # ___________________________________________________________________________
 #
 # Pyomo: Python Optimization Modeling Objects
-# Copyright (c) 2008-2022
+# Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 # Under the terms of Contract DE-NA0003525 with National Technology and
 # Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/sensitivity_toolbox/examples/feedbackController.py b/pyomo/contrib/sensitivity_toolbox/examples/feedbackController.py
index 1112a0c82b3..d973bedf5ba 100644
--- a/pyomo/contrib/sensitivity_toolbox/examples/feedbackController.py
+++ b/pyomo/contrib/sensitivity_toolbox/examples/feedbackController.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/sensitivity_toolbox/examples/parameter.py b/pyomo/contrib/sensitivity_toolbox/examples/parameter.py
index 3ed1628f2c2..85d31d3303e 100644
--- a/pyomo/contrib/sensitivity_toolbox/examples/parameter.py
+++ b/pyomo/contrib/sensitivity_toolbox/examples/parameter.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/sensitivity_toolbox/examples/parameter_kaug.py b/pyomo/contrib/sensitivity_toolbox/examples/parameter_kaug.py
index f54e7903442..c5e61307046 100644
--- a/pyomo/contrib/sensitivity_toolbox/examples/parameter_kaug.py
+++ b/pyomo/contrib/sensitivity_toolbox/examples/parameter_kaug.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/sensitivity_toolbox/examples/rangeInequality.py b/pyomo/contrib/sensitivity_toolbox/examples/rangeInequality.py
index 39e4d26f695..b06cc8390d2 100644
--- a/pyomo/contrib/sensitivity_toolbox/examples/rangeInequality.py
+++ b/pyomo/contrib/sensitivity_toolbox/examples/rangeInequality.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/sensitivity_toolbox/examples/rooney_biegler.py b/pyomo/contrib/sensitivity_toolbox/examples/rooney_biegler.py
index f058e8189dc..3efb20bd44b 100644
--- a/pyomo/contrib/sensitivity_toolbox/examples/rooney_biegler.py
+++ b/pyomo/contrib/sensitivity_toolbox/examples/rooney_biegler.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 ##############################################################################
 # Institute for the Design of Advanced Energy Systems Process Systems
 # Engineering Framework (IDAES PSE Framework) Copyright (c) 2018-2019, by the
diff --git a/pyomo/contrib/sensitivity_toolbox/k_aug.py b/pyomo/contrib/sensitivity_toolbox/k_aug.py
index 8d739506492..a7fc10569fe 100644
--- a/pyomo/contrib/sensitivity_toolbox/k_aug.py
+++ b/pyomo/contrib/sensitivity_toolbox/k_aug.py
@@ -1,7 +1,18 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # ______________________________________________________________________________
 #
 # Pyomo: Python Optimization Modeling Objects
-# Copyright (c) 2008-2022
+# Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 # Under the terms of Contract DE-NA0003525 with National Technology and
 # Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/sensitivity_toolbox/sens.py b/pyomo/contrib/sensitivity_toolbox/sens.py
index e1c69d75974..a3d69b2c7b1 100644
--- a/pyomo/contrib/sensitivity_toolbox/sens.py
+++ b/pyomo/contrib/sensitivity_toolbox/sens.py
@@ -1,7 +1,18 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # ______________________________________________________________________________
 #
 # Pyomo: Python Optimization Modeling Objects
-# Copyright (c) 2008-2022
+# Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 # Under the terms of Contract DE-NA0003525 with National Technology and
 # Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/sensitivity_toolbox/tests/__init__.py b/pyomo/contrib/sensitivity_toolbox/tests/__init__.py
index 557846ee521..53f447ece43 100644
--- a/pyomo/contrib/sensitivity_toolbox/tests/__init__.py
+++ b/pyomo/contrib/sensitivity_toolbox/tests/__init__.py
@@ -1,7 +1,18 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # ___________________________________________________________________________
 #
 # Pyomo: Python Optimization Modeling Objects
-# Copyright (c) 2008-2022
+# Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 # Under the terms of Contract DE-NA0003525 with National Technology and
 # Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/sensitivity_toolbox/tests/test_k_aug_interface.py b/pyomo/contrib/sensitivity_toolbox/tests/test_k_aug_interface.py
index 8c14cfc91d0..e941656a392 100644
--- a/pyomo/contrib/sensitivity_toolbox/tests/test_k_aug_interface.py
+++ b/pyomo/contrib/sensitivity_toolbox/tests/test_k_aug_interface.py
@@ -1,7 +1,18 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # ____________________________________________________________________________
 #
 # Pyomo: Python Optimization Modeling Objects
-# Copyright (c) 2008-2022
+# Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 # Under the terms of Contract DE-NA0003525 with National Technology and
 # Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/sensitivity_toolbox/tests/test_sens.py b/pyomo/contrib/sensitivity_toolbox/tests/test_sens.py
index f4b3fb5548c..69cf0303987 100644
--- a/pyomo/contrib/sensitivity_toolbox/tests/test_sens.py
+++ b/pyomo/contrib/sensitivity_toolbox/tests/test_sens.py
@@ -1,7 +1,18 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # ____________________________________________________________________________
 #
 # Pyomo: Python Optimization Modeling Objects
-# Copyright (c) 2008-2022
+# Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 # Under the terms of Contract DE-NA0003525 with National Technology and
 # Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/sensitivity_toolbox/tests/test_sens_unit.py b/pyomo/contrib/sensitivity_toolbox/tests/test_sens_unit.py
index 05faada3007..9f4bcb2b497 100644
--- a/pyomo/contrib/sensitivity_toolbox/tests/test_sens_unit.py
+++ b/pyomo/contrib/sensitivity_toolbox/tests/test_sens_unit.py
@@ -1,7 +1,18 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # ____________________________________________________________________________
 #
 # Pyomo: Python Optimization Modeling Objects
-# Copyright (c) 2008-2022
+# Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 # Under the terms of Contract DE-NA0003525 with National Technology and
 # Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/simplemodel/__init__.py b/pyomo/contrib/simplemodel/__init__.py
index 4fa4fa2dd16..f2f4922223e 100644
--- a/pyomo/contrib/simplemodel/__init__.py
+++ b/pyomo/contrib/simplemodel/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/simplification/__init__.py b/pyomo/contrib/simplification/__init__.py
new file mode 100644
index 00000000000..c6111ddcb89
--- /dev/null
+++ b/pyomo/contrib/simplification/__init__.py
@@ -0,0 +1,12 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+from .simplify import Simplifier
diff --git a/pyomo/contrib/simplification/build.py b/pyomo/contrib/simplification/build.py
new file mode 100644
index 00000000000..b4bec63088a
--- /dev/null
+++ b/pyomo/contrib/simplification/build.py
@@ -0,0 +1,209 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import glob
+import logging
+import os
+import shutil
+import sys
+import subprocess
+
+from pyomo.common.download import FileDownloader
+from pyomo.common.envvar import PYOMO_CONFIG_DIR
+from pyomo.common.fileutils import find_library, this_file_dir
+from pyomo.common.tempfiles import TempfileManager
+
+logger = logging.getLogger(__name__ if __name__ != '__main__' else 'pyomo')
+
+
+def build_ginac_library(parallel=None, argv=None, env=None):
+    sys.stdout.write("\n**** Building GiNaC library ****\n")
+
+    configure_cmd = [
+        os.path.join('.', 'configure'),
+        '--prefix=' + PYOMO_CONFIG_DIR,
+        '--disable-static',
+    ]
+    make_cmd = ['make']
+    if parallel:
+        make_cmd.append(f'-j{parallel}')
+    install_cmd = ['make', 'install']
+
+    env = dict(os.environ)
+    pcdir = os.path.join(PYOMO_CONFIG_DIR, 'lib', 'pkgconfig')
+    if 'PKG_CONFIG_PATH' in env:
+        pcdir += os.pathsep + env['PKG_CONFIG_PATH']
+    env['PKG_CONFIG_PATH'] = pcdir
+
+    with TempfileManager.new_context() as tempfile:
+        tmpdir = tempfile.mkdtemp()
+
+        downloader = FileDownloader()
+        if argv:
+            downloader.parse_args(argv)
+
+        url = 'https://www.ginac.de/CLN/cln-1.3.7.tar.bz2'
+        cln_dir = os.path.join(tmpdir, 'cln')
+        downloader.set_destination_filename(cln_dir)
+        logger.info(
+            "Fetching CLN from %s and installing it to %s"
+            % (url, downloader.destination())
+        )
+        downloader.get_tar_archive(url, dirOffset=1)
+        assert subprocess.run(configure_cmd, cwd=cln_dir, env=env).returncode == 0
+        logger.info("\nBuilding CLN\n")
+        assert subprocess.run(make_cmd, cwd=cln_dir, env=env).returncode == 0
+        assert subprocess.run(install_cmd, cwd=cln_dir, env=env).returncode == 0
+
+        url = 'https://www.ginac.de/ginac-1.8.7.tar.bz2'
+        ginac_dir = os.path.join(tmpdir, 'ginac')
+        downloader.set_destination_filename(ginac_dir)
+        logger.info(
+            "Fetching GiNaC from %s and installing it to %s"
+            % (url, downloader.destination())
+        )
+        downloader.get_tar_archive(url, dirOffset=1)
+        assert subprocess.run(configure_cmd, cwd=ginac_dir, env=env).returncode == 0
+        logger.info("\nBuilding GiNaC\n")
+        assert subprocess.run(make_cmd, cwd=ginac_dir, env=env).returncode == 0
+        assert subprocess.run(install_cmd, cwd=ginac_dir, env=env).returncode == 0
+        print("Installed GiNaC to %s" % (ginac_dir,))
+
+
+def _find_include(libdir, incpaths):
+    rel_path = ('include',) + incpaths
+    while 1:
+        basedir = os.path.dirname(libdir)
+        if not basedir or basedir == libdir:
+            return None
+        if os.path.exists(os.path.join(basedir, *rel_path)):
+            return os.path.join(basedir, *(rel_path[: -len(incpaths)]))
+        libdir = basedir
+
+
+def build_ginac_interface(parallel=None, args=None):
+    from distutils.dist import Distribution
+    from pybind11.setup_helpers import Pybind11Extension, build_ext
+    from pyomo.common.cmake_builder import handleReadonly
+
+    sys.stdout.write("\n**** Building GiNaC interface ****\n")
+
+    if args is None:
+        args = []
+    sources = [
+        os.path.join(this_file_dir(), 'ginac', 'src', fname)
+        for fname in ['ginac_interface.cpp']
+    ]
+
+    ginac_lib = find_library('ginac')
+    if not ginac_lib:
+        raise RuntimeError(
+            'could not find the GiNaC library; please make sure either to install '
+            'the library and development headers system-wide, or include the '
+            'path to the library in the LD_LIBRARY_PATH environment variable'
+        )
+    ginac_lib_dir = os.path.dirname(ginac_lib)
+    ginac_include_dir = _find_include(ginac_lib_dir, ('ginac', 'ginac.h'))
+    if not ginac_include_dir:
+        raise RuntimeError('could not find GiNaC include directory')
+
+    cln_lib = find_library('cln')
+    if not cln_lib:
+        raise RuntimeError(
+            'could not find the CLN library; please make sure either to install '
+            'the library and development headers system-wide, or include the '
+            'path to the library in the LD_LIBRARY_PATH environment variable'
+        )
+    cln_lib_dir = os.path.dirname(cln_lib)
+    cln_include_dir = _find_include(cln_lib_dir, ('cln', 'cln.h'))
+    if not cln_include_dir:
+        raise RuntimeError('could not find CLN include directory')
+
+    extra_args = ['-std=c++11']
+    ext = Pybind11Extension(
+        'ginac_interface',
+        sources=sources,
+        language='c++',
+        include_dirs=[cln_include_dir, ginac_include_dir],
+        library_dirs=[cln_lib_dir, ginac_lib_dir],
+        libraries=['cln', 'ginac'],
+        extra_compile_args=extra_args,
+    )
+
+    class ginacBuildExt(build_ext):
+        def run(self):
+            basedir = os.path.abspath(os.path.curdir)
+            with TempfileManager.new_context() as tempfile:
+                if self.inplace:
+                    tmpdir = os.path.join(this_file_dir(), 'ginac')
+                else:
+                    tmpdir = os.path.abspath(tempfile.mkdtemp())
+                sys.stdout.write("Building in '%s'\n" % tmpdir)
+                os.chdir(tmpdir)
+                super(ginacBuildExt, self).run()
+                if not self.inplace:
+                    library = glob.glob("build/*/ginac_interface.*")[0]
+                    target = os.path.join(
+                        PYOMO_CONFIG_DIR,
+                        'lib',
+                        'python%s.%s' % sys.version_info[:2],
+                        'site-packages',
+                        '.',
+                    )
+                    if not os.path.exists(target):
+                        os.makedirs(target)
+                    sys.stdout.write(f"Installing {library} in {target}\n")
+                    shutil.copy(library, target)
+
+    package_config = {
+        'name': 'ginac_interface',
+        'packages': [],
+        'ext_modules': [ext],
+        'cmdclass': {"build_ext": ginacBuildExt},
+    }
+
+    dist = Distribution(package_config)
+    dist.script_args = ['build_ext'] + args
+    dist.parse_command_line()
+    dist.run_command('build_ext')
+
+
+class GiNaCInterfaceBuilder(object):
+    def __call__(self, parallel):
+        return build_ginac_interface(parallel)
+
+    def skip(self):
+        return not find_library('ginac')
+
+
+if __name__ == '__main__':
+    import argparse
+
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        "-j",
+        dest='parallel',
+        type=int,
+        default=None,
+        help="Enable parallel build with PARALLEL cores",
+    )
+    parser.add_argument(
+        "--build-deps",
+        dest='build_deps',
+        action='store_true',
+        default=False,
+        help="Download and build the CLN/GiNaC libraries",
+    )
+    options, argv = parser.parse_known_args(sys.argv)
+    logging.getLogger('pyomo').setLevel(logging.INFO)
+    if options.build_deps:
+        build_ginac_library(options.parallel, [])
+    build_ginac_interface(options.parallel, argv[1:])
diff --git a/pyomo/contrib/simplification/ginac/__init__.py b/pyomo/contrib/simplification/ginac/__init__.py
new file mode 100644
index 00000000000..6896bec12c4
--- /dev/null
+++ b/pyomo/contrib/simplification/ginac/__init__.py
@@ -0,0 +1,52 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+from pyomo.common.dependencies import attempt_import as _attempt_import
+
+
+def _importer():
+    import os
+    import sys
+    from ctypes import cdll
+    from pyomo.common.envvar import PYOMO_CONFIG_DIR
+    from pyomo.common.fileutils import find_library
+
+    try:
+        pyomo_config_dir = os.path.join(
+            PYOMO_CONFIG_DIR,
+            'lib',
+            'python%s.%s' % sys.version_info[:2],
+            'site-packages',
+        )
+        sys.path.insert(0, pyomo_config_dir)
+        # GiNaC needs 2 libraries that are generally dynamically linked
+        # to the interface library.  If we built those ourselves, then
+        # the libraries will be PYOMO_CONFIG_DIR/lib ... but that
+        # directory is very likely to NOT be on the library search path
+        # when the Python interpreter was started.  We will manually
+        # look for those two libraries, and if we find them, load them
+        # into this process (so the interface can find them)
+        for lib in ('cln', 'ginac'):
+            fname = find_library(lib)
+            if fname is not None:
+                cdll.LoadLibrary(fname)
+
+        import ginac_interface
+    except ImportError:
+        from . import ginac_interface
+    finally:
+        assert sys.path[0] == pyomo_config_dir
+        sys.path.pop(0)
+
+    return ginac_interface
+
+
+interface, interface_available = _attempt_import('ginac_interface', importer=_importer)
diff --git a/pyomo/contrib/simplification/ginac/src/ginac_interface.cpp b/pyomo/contrib/simplification/ginac/src/ginac_interface.cpp
new file mode 100644
index 00000000000..9b05baf71ca
--- /dev/null
+++ b/pyomo/contrib/simplification/ginac/src/ginac_interface.cpp
@@ -0,0 +1,332 @@
+//  ___________________________________________________________________________
+//
+//  Pyomo: Python Optimization Modeling Objects
+//  Copyright (c) 2008-2024
+//  National Technology and Engineering Solutions of Sandia, LLC
+//  Under the terms of Contract DE-NA0003525 with National Technology and
+//  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+//  rights in this software.
+//  This software is distributed under the 3-clause BSD License.
+//  ___________________________________________________________________________
+
+#include "ginac_interface.hpp"
+
+
+bool is_integer(double x) {
+  return std::floor(x) == x;
+}
+
+
+ex ginac_expr_from_pyomo_node(
+  py::handle expr, 
+  std::unordered_map<long, ex> &leaf_map, 
+  std::unordered_map<ex, py::object> &ginac_pyomo_map, 
+  PyomoExprTypes &expr_types,
+  bool symbolic_solver_labels
+  ) {
+  ex res;
+  ExprType tmp_type =
+      expr_types.expr_type_map[py::type::of(expr)].cast<ExprType>();
+
+  switch (tmp_type) {
+  case py_float: {
+    double val = expr.cast<double>();
+    if (is_integer(val)) {
+      res = numeric((long) val);
+    }
+    else {
+      res = numeric(val);
+    }
+    break;
+  }
+  case var: {
+    long expr_id = expr_types.id(expr).cast<long>();
+    if (leaf_map.count(expr_id) == 0) {
+      std::string vname;
+      if (symbolic_solver_labels) {
+        vname = expr.attr("name").cast<std::string>();
+      }
+      else {
+        vname = "x" + std::to_string(expr_id);
+      }
+      py::object lb = expr.attr("lb");
+      if (lb.is_none() || lb.cast<double>() < 0) {
+        leaf_map[expr_id] = realsymbol(vname);
+      }
+      else {
+        leaf_map[expr_id] = possymbol(vname);
+      }
+      ginac_pyomo_map[leaf_map[expr_id]] = expr.cast<py::object>();
+    }
+    res = leaf_map[expr_id];
+    break;
+  }
+  case param: {
+    long expr_id = expr_types.id(expr).cast<long>();
+    if (leaf_map.count(expr_id) == 0) {
+      std::string pname;
+      if (symbolic_solver_labels) {
+        pname = expr.attr("name").cast<std::string>();
+      }
+      else {
+        pname = "p" + std::to_string(expr_id);
+      }
+      leaf_map[expr_id] = realsymbol(pname);
+      ginac_pyomo_map[leaf_map[expr_id]] = expr.cast<py::object>();
+    }
+    res = leaf_map[expr_id];
+    break;
+  }
+  case product: {
+    py::list pyomo_args = expr.attr("args");
+    res = ginac_expr_from_pyomo_node(pyomo_args[0], leaf_map, ginac_pyomo_map, expr_types, symbolic_solver_labels) * ginac_expr_from_pyomo_node(pyomo_args[1], leaf_map, ginac_pyomo_map, expr_types, symbolic_solver_labels);
+    break;
+  }
+  case sum: {
+    py::list pyomo_args = expr.attr("args");
+    for (py::handle arg : pyomo_args) {
+      res += ginac_expr_from_pyomo_node(arg, leaf_map, ginac_pyomo_map, expr_types, symbolic_solver_labels);
+    }
+    break;
+  }
+  case negation: {
+    py::list pyomo_args = expr.attr("args");
+    res = - ginac_expr_from_pyomo_node(pyomo_args[0], leaf_map, ginac_pyomo_map, expr_types, symbolic_solver_labels);
+    break;
+  }
+  case external_func: {
+    long expr_id = expr_types.id(expr).cast<long>();
+    if (leaf_map.count(expr_id) == 0) {
+      leaf_map[expr_id] = realsymbol("f" + std::to_string(expr_id));
+      ginac_pyomo_map[leaf_map[expr_id]] = expr.cast<py::object>();
+    }
+    res = leaf_map[expr_id];
+    break;
+  }
+  case ExprType::power: {
+    py::list pyomo_args = expr.attr("args");
+    res = pow(ginac_expr_from_pyomo_node(pyomo_args[0], leaf_map, ginac_pyomo_map, expr_types, symbolic_solver_labels), ginac_expr_from_pyomo_node(pyomo_args[1], leaf_map, ginac_pyomo_map, expr_types, symbolic_solver_labels));
+    break;
+  }
+  case division: {
+    py::list pyomo_args = expr.attr("args");
+    res = ginac_expr_from_pyomo_node(pyomo_args[0], leaf_map, ginac_pyomo_map, expr_types, symbolic_solver_labels) / ginac_expr_from_pyomo_node(pyomo_args[1], leaf_map, ginac_pyomo_map, expr_types, symbolic_solver_labels);
+    break;
+  }
+  case unary_func: {
+    std::string function_name = expr.attr("getname")().cast<std::string>();
+    py::list pyomo_args = expr.attr("args");
+    if (function_name == "exp")
+      res = exp(ginac_expr_from_pyomo_node(pyomo_args[0], leaf_map, ginac_pyomo_map, expr_types, symbolic_solver_labels));
+    else if (function_name == "log")
+      res = log(ginac_expr_from_pyomo_node(pyomo_args[0], leaf_map, ginac_pyomo_map, expr_types, symbolic_solver_labels));
+    else if (function_name == "sin")
+      res = sin(ginac_expr_from_pyomo_node(pyomo_args[0], leaf_map, ginac_pyomo_map, expr_types, symbolic_solver_labels));
+    else if (function_name == "cos")
+      res = cos(ginac_expr_from_pyomo_node(pyomo_args[0], leaf_map, ginac_pyomo_map, expr_types, symbolic_solver_labels));
+    else if (function_name == "tan")
+      res = tan(ginac_expr_from_pyomo_node(pyomo_args[0], leaf_map, ginac_pyomo_map, expr_types, symbolic_solver_labels));
+    else if (function_name == "asin")
+      res = asin(ginac_expr_from_pyomo_node(pyomo_args[0], leaf_map, ginac_pyomo_map, expr_types, symbolic_solver_labels));
+    else if (function_name == "acos")
+      res = acos(ginac_expr_from_pyomo_node(pyomo_args[0], leaf_map, ginac_pyomo_map, expr_types, symbolic_solver_labels));
+    else if (function_name == "atan")
+      res = atan(ginac_expr_from_pyomo_node(pyomo_args[0], leaf_map, ginac_pyomo_map, expr_types, symbolic_solver_labels));
+    else if (function_name == "sqrt")
+      res = sqrt(ginac_expr_from_pyomo_node(pyomo_args[0], leaf_map, ginac_pyomo_map, expr_types, symbolic_solver_labels));
+    else
+      throw py::value_error("Unrecognized expression type: " + function_name);
+    break;
+  }
+  case linear: {
+    py::list pyomo_args = expr.attr("args");
+    for (py::handle arg : pyomo_args) {
+      res += ginac_expr_from_pyomo_node(arg, leaf_map, ginac_pyomo_map, expr_types, symbolic_solver_labels);
+    }
+    break;
+  }
+  case named_expr: {
+    res = ginac_expr_from_pyomo_node(expr.attr("expr"), leaf_map, ginac_pyomo_map, expr_types, symbolic_solver_labels);
+    break;
+  }
+  case numeric_constant: {
+    res = numeric(expr.attr("value").cast<double>());
+    break;
+  }
+  case pyomo_unit: {
+    res = numeric(1.0);
+    break;
+  }
+  case unary_abs: {
+    py::list pyomo_args = expr.attr("args");
+    res = abs(ginac_expr_from_pyomo_node(pyomo_args[0], leaf_map, ginac_pyomo_map, expr_types, symbolic_solver_labels));
+    break;
+  }
+  default: {
+    throw py::value_error("Unrecognized expression type: " +
+                          expr_types.builtins.attr("str")(py::type::of(expr))
+                              .cast<std::string>());
+    break;
+  }
+  }
+  return res;
+}
+
+ex pyomo_expr_to_ginac_expr(
+  py::handle expr,
+  std::unordered_map<long, ex> &leaf_map,
+  std::unordered_map<ex, py::object> &ginac_pyomo_map,
+  PyomoExprTypes &expr_types,
+  bool symbolic_solver_labels
+  ) {
+    ex res = ginac_expr_from_pyomo_node(expr, leaf_map, ginac_pyomo_map, expr_types, symbolic_solver_labels);
+    return res;
+  }
+
+ex pyomo_to_ginac(py::handle expr, PyomoExprTypes &expr_types) {
+  std::unordered_map<long, ex> leaf_map;
+  std::unordered_map<ex, py::object> ginac_pyomo_map;
+  ex res = ginac_expr_from_pyomo_node(expr, leaf_map, ginac_pyomo_map, expr_types, true);
+  return res;
+}
+
+
+class GinacToPyomoVisitor 
+: public visitor, 
+  public symbol::visitor, 
+  public numeric::visitor, 
+  public add::visitor, 
+  public mul::visitor, 
+  public GiNaC::power::visitor, 
+  public function::visitor, 
+  public basic::visitor
+{
+  public:
+  std::unordered_map<ex, py::object> *leaf_map;
+  std::unordered_map<ex, py::object> node_map;
+  PyomoExprTypes *expr_types;
+
+  GinacToPyomoVisitor(std::unordered_map<ex, py::object> *_leaf_map, PyomoExprTypes *_expr_types) : leaf_map(_leaf_map), expr_types(_expr_types) {}
+  ~GinacToPyomoVisitor() = default;
+
+  void visit(const symbol& e) {
+    node_map[e] = leaf_map->at(e);
+  }
+
+  void visit(const numeric& e) {
+    double val = e.to_double();
+    node_map[e] = expr_types->NumericConstant(py::cast(val));
+  }
+
+  void visit(const add& e) {
+    size_t n = e.nops();
+    py::object pe = node_map[e.op(0)];
+    for (unsigned long ndx=1; ndx < n; ++ndx) {
+      pe = pe.attr("__add__")(node_map[e.op(ndx)]);
+    }
+    node_map[e] = pe;
+  }
+
+  void visit(const mul& e) {
+    size_t n = e.nops();
+    py::object pe = node_map[e.op(0)];
+    for (unsigned long ndx=1; ndx < n; ++ndx) {
+      pe = pe.attr("__mul__")(node_map[e.op(ndx)]);
+    }
+    node_map[e] = pe;
+  }
+
+  void visit(const GiNaC::power& e) {
+    py::object arg1 = node_map[e.op(0)];
+    py::object arg2 = node_map[e.op(1)];
+    py::object pe = arg1.attr("__pow__")(arg2);
+    node_map[e] = pe;
+  }
+
+  void visit(const function& e) {
+    py::object arg = node_map[e.op(0)];
+    std::string func_type = e.get_name();
+    py::object pe;
+    if (func_type == "exp") {
+      pe = expr_types->exp(arg);
+    }
+    else if (func_type == "log") {
+      pe = expr_types->log(arg);
+    }
+    else if (func_type == "sin") {
+      pe = expr_types->sin(arg);
+    }
+    else if (func_type == "cos") {
+      pe = expr_types->cos(arg);
+    }
+    else if (func_type == "tan") {
+      pe = expr_types->tan(arg);
+    }
+    else if (func_type == "asin") {
+      pe = expr_types->asin(arg);
+    }
+    else if (func_type == "acos") {
+      pe = expr_types->acos(arg);
+    }
+    else if (func_type == "atan") {
+      pe = expr_types->atan(arg);
+    }
+    else if (func_type == "sqrt") {
+      pe = expr_types->sqrt(arg);
+    }
+    else {
+      throw py::value_error("unrecognized unary function: " + func_type);
+    }
+    node_map[e] = pe;
+  }
+
+  void visit(const basic& e) {
+    throw py::value_error("unrecognized ginac expression type");
+  }
+};
+
+
+ex GinacInterface::to_ginac(py::handle expr) {
+  return pyomo_expr_to_ginac_expr(expr, leaf_map, ginac_pyomo_map, expr_types, symbolic_solver_labels);
+}
+
+py::object GinacInterface::from_ginac(ex &ge) {
+  GinacToPyomoVisitor v(&ginac_pyomo_map, &expr_types);
+  ge.traverse_postorder(v);
+  return v.node_map[ge];
+}
+
+PYBIND11_MODULE(ginac_interface, m) {
+  m.def("pyomo_to_ginac", &pyomo_to_ginac);
+  py::class_<PyomoExprTypes>(m, "PyomoExprTypes", py::module_local())
+    .def(py::init<>());
+  py::class_<ex>(m, "ginac_expression")
+    .def("expand", [](ex &ge) {
+      return ge.expand();
+    })
+    .def("normal", &ex::normal)
+    .def("__str__", [](ex &ge) {
+	std::ostringstream stream;
+	stream << ge;
+	return stream.str();
+      });
+  py::class_<GinacInterface>(m, "GinacInterface")
+    .def(py::init<bool>())
+    .def("to_ginac", &GinacInterface::to_ginac)
+    .def("from_ginac", &GinacInterface::from_ginac);
+  py::enum_<ExprType>(m, "ExprType", py::module_local())
+      .value("py_float", ExprType::py_float)
+      .value("var", ExprType::var)
+      .value("param", ExprType::param)
+      .value("product", ExprType::product)
+      .value("sum", ExprType::sum)
+      .value("negation", ExprType::negation)
+      .value("external_func", ExprType::external_func)
+      .value("power", ExprType::power)
+      .value("division", ExprType::division)
+      .value("unary_func", ExprType::unary_func)
+      .value("linear", ExprType::linear)
+      .value("named_expr", ExprType::named_expr)
+      .value("numeric_constant", ExprType::numeric_constant)
+      .export_values();
+}
diff --git a/pyomo/contrib/simplification/ginac/src/ginac_interface.hpp b/pyomo/contrib/simplification/ginac/src/ginac_interface.hpp
new file mode 100644
index 00000000000..bc5b0d7b6fc
--- /dev/null
+++ b/pyomo/contrib/simplification/ginac/src/ginac_interface.hpp
@@ -0,0 +1,190 @@
+#pragma once
+#include <algorithm>
+#include <cmath>
+#include <cstdlib>
+#include <fstream>
+#include <iostream>
+#include <iterator>
+#include <list>
+#include <memory>
+#include <pybind11/numpy.h>
+#include <pybind11/operators.h>
+#include <pybind11/pybind11.h>
+#include <pybind11/stl.h>
+#include <set>
+#include <sstream>
+#include <stdexcept>
+#include <tuple>
+#include <typeinfo>
+#include <unordered_map>
+#include <unordered_set>
+#include <utility>
+#include <vector>
+#include <ginac/ginac.h>
+#define PYBIND11_DETAILED_ERROR_MESSAGES
+
+namespace py = pybind11;
+using namespace pybind11::literals;
+using namespace GiNaC;
+
+enum ExprType {
+  py_float = 0,
+  var = 1,
+  param = 2,
+  product = 3,
+  sum = 4,
+  negation = 5,
+  external_func = 6,
+  power = 7,
+  division = 8,
+  unary_func = 9,
+  linear = 10,
+  named_expr = 11,
+  numeric_constant = 12,
+  pyomo_unit = 13,
+  unary_abs = 14
+};
+
+class PyomoExprTypes {
+public:
+  PyomoExprTypes() {
+    expr_type_map[int_] = py_float;
+    expr_type_map[float_] = py_float;
+    expr_type_map[np_int16] = py_float;
+    expr_type_map[np_int32] = py_float;
+    expr_type_map[np_int64] = py_float;
+    expr_type_map[np_longlong] = py_float;
+    expr_type_map[np_uint16] = py_float;
+    expr_type_map[np_uint32] = py_float;
+    expr_type_map[np_uint64] = py_float;
+    expr_type_map[np_ulonglong] = py_float;
+    expr_type_map[np_float16] = py_float;
+    expr_type_map[np_float32] = py_float;
+    expr_type_map[np_float64] = py_float;
+    expr_type_map[ScalarVar] = var;
+    expr_type_map[_GeneralVarData] = var;
+    expr_type_map[AutoLinkedBinaryVar] = var;
+    expr_type_map[ScalarParam] = param;
+    expr_type_map[_ParamData] = param;
+    expr_type_map[MonomialTermExpression] = product;
+    expr_type_map[ProductExpression] = product;
+    expr_type_map[NPV_ProductExpression] = product;
+    expr_type_map[SumExpression] = sum;
+    expr_type_map[NPV_SumExpression] = sum;
+    expr_type_map[NegationExpression] = negation;
+    expr_type_map[NPV_NegationExpression] = negation;
+    expr_type_map[ExternalFunctionExpression] = external_func;
+    expr_type_map[NPV_ExternalFunctionExpression] = external_func;
+    expr_type_map[PowExpression] = ExprType::power;
+    expr_type_map[NPV_PowExpression] = ExprType::power;
+    expr_type_map[DivisionExpression] = division;
+    expr_type_map[NPV_DivisionExpression] = division;
+    expr_type_map[UnaryFunctionExpression] = unary_func;
+    expr_type_map[NPV_UnaryFunctionExpression] = unary_func;
+    expr_type_map[LinearExpression] = linear;
+    expr_type_map[_GeneralExpressionData] = named_expr;
+    expr_type_map[ScalarExpression] = named_expr;
+    expr_type_map[Integral] = named_expr;
+    expr_type_map[ScalarIntegral] = named_expr;
+    expr_type_map[NumericConstant] = numeric_constant;
+    expr_type_map[_PyomoUnit] = pyomo_unit;
+    expr_type_map[AbsExpression] = unary_abs;
+    expr_type_map[NPV_AbsExpression] = unary_abs;
+  }
+  ~PyomoExprTypes() = default;
+  py::int_ ione = 1;
+  py::float_ fone = 1.0;
+  py::type int_ = py::type::of(ione);
+  py::type float_ = py::type::of(fone);
+  py::object np = py::module_::import("numpy");
+  py::type np_int16 = np.attr("int16");
+  py::type np_int32 = np.attr("int32");
+  py::type np_int64 = np.attr("int64");
+  py::type np_longlong = np.attr("longlong");
+  py::type np_uint16 = np.attr("uint16");
+  py::type np_uint32 = np.attr("uint32");
+  py::type np_uint64 = np.attr("uint64");
+  py::type np_ulonglong = np.attr("ulonglong");
+  py::type np_float16 = np.attr("float16");
+  py::type np_float32 = np.attr("float32");
+  py::type np_float64 = np.attr("float64");
+  py::object ScalarParam =
+      py::module_::import("pyomo.core.base.param").attr("ScalarParam");
+  py::object _ParamData =
+      py::module_::import("pyomo.core.base.param").attr("_ParamData");
+  py::object ScalarVar =
+      py::module_::import("pyomo.core.base.var").attr("ScalarVar");
+  py::object _GeneralVarData =
+      py::module_::import("pyomo.core.base.var").attr("_GeneralVarData");
+  py::object AutoLinkedBinaryVar =
+      py::module_::import("pyomo.gdp.disjunct").attr("AutoLinkedBinaryVar");
+  py::object numeric_expr = py::module_::import("pyomo.core.expr.numeric_expr");
+  py::object NegationExpression = numeric_expr.attr("NegationExpression");
+  py::object NPV_NegationExpression =
+      numeric_expr.attr("NPV_NegationExpression");
+  py::object ExternalFunctionExpression =
+      numeric_expr.attr("ExternalFunctionExpression");
+  py::object NPV_ExternalFunctionExpression =
+      numeric_expr.attr("NPV_ExternalFunctionExpression");
+  py::object PowExpression = numeric_expr.attr("PowExpression");
+  py::object NPV_PowExpression = numeric_expr.attr("NPV_PowExpression");
+  py::object ProductExpression = numeric_expr.attr("ProductExpression");
+  py::object NPV_ProductExpression = numeric_expr.attr("NPV_ProductExpression");
+  py::object MonomialTermExpression =
+      numeric_expr.attr("MonomialTermExpression");
+  py::object DivisionExpression = numeric_expr.attr("DivisionExpression");
+  py::object NPV_DivisionExpression =
+      numeric_expr.attr("NPV_DivisionExpression");
+  py::object SumExpression = numeric_expr.attr("SumExpression");
+  py::object NPV_SumExpression = numeric_expr.attr("NPV_SumExpression");
+  py::object UnaryFunctionExpression =
+      numeric_expr.attr("UnaryFunctionExpression");
+  py::object AbsExpression = numeric_expr.attr("AbsExpression");
+  py::object NPV_AbsExpression = numeric_expr.attr("NPV_AbsExpression");
+  py::object NPV_UnaryFunctionExpression =
+      numeric_expr.attr("NPV_UnaryFunctionExpression");
+  py::object LinearExpression = numeric_expr.attr("LinearExpression");
+  py::object NumericConstant =
+      py::module_::import("pyomo.core.expr.numvalue").attr("NumericConstant");
+  py::object expr_module = py::module_::import("pyomo.core.base.expression");
+  py::object _GeneralExpressionData =
+      expr_module.attr("_GeneralExpressionData");
+  py::object ScalarExpression = expr_module.attr("ScalarExpression");
+  py::object ScalarIntegral =
+      py::module_::import("pyomo.dae.integral").attr("ScalarIntegral");
+  py::object Integral =
+      py::module_::import("pyomo.dae.integral").attr("Integral");
+  py::object _PyomoUnit =
+      py::module_::import("pyomo.core.base.units_container").attr("_PyomoUnit");
+  py::object exp = numeric_expr.attr("exp");
+  py::object log = numeric_expr.attr("log");
+  py::object sin = numeric_expr.attr("sin");
+  py::object cos = numeric_expr.attr("cos");
+  py::object tan = numeric_expr.attr("tan");
+  py::object asin = numeric_expr.attr("asin");
+  py::object acos = numeric_expr.attr("acos");
+  py::object atan = numeric_expr.attr("atan");
+  py::object sqrt = numeric_expr.attr("sqrt");
+  py::object builtins = py::module_::import("builtins");
+  py::object id = builtins.attr("id");
+  py::object len = builtins.attr("len");
+  py::dict expr_type_map;
+};
+
+ex pyomo_to_ginac(py::handle expr, PyomoExprTypes &expr_types);
+
+
+class GinacInterface {
+    public:
+    std::unordered_map<long, ex> leaf_map;
+    std::unordered_map<ex, py::object> ginac_pyomo_map;
+    PyomoExprTypes expr_types;
+    bool symbolic_solver_labels = false;
+
+    GinacInterface() = default;
+    GinacInterface(bool _symbolic_solver_labels) : symbolic_solver_labels(_symbolic_solver_labels) {}
+    ~GinacInterface() = default;
+
+    ex to_ginac(py::handle expr);
+    py::object from_ginac(ex &ginac_expr);
+};
diff --git a/pyomo/contrib/simplification/plugins.py b/pyomo/contrib/simplification/plugins.py
new file mode 100644
index 00000000000..6b08f7be4d7
--- /dev/null
+++ b/pyomo/contrib/simplification/plugins.py
@@ -0,0 +1,17 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+from pyomo.common.extensions import ExtensionBuilderFactory
+from .build import GiNaCInterfaceBuilder
+
+
+def load():
+    ExtensionBuilderFactory.register('ginac')(GiNaCInterfaceBuilder)
diff --git a/pyomo/contrib/simplification/simplify.py b/pyomo/contrib/simplification/simplify.py
new file mode 100644
index 00000000000..874b5b1e801
--- /dev/null
+++ b/pyomo/contrib/simplification/simplify.py
@@ -0,0 +1,75 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import logging
+import warnings
+
+from pyomo.common.enums import NamedIntEnum
+from pyomo.core.expr.sympy_tools import sympy2pyomo_expression, sympyify_expression
+from pyomo.core.expr.numeric_expr import NumericExpression
+from pyomo.core.expr.numvalue import value, is_constant
+
+from pyomo.contrib.simplification.ginac import (
+    interface as ginac_interface,
+    interface_available as ginac_available,
+)
+
+
+def simplify_with_sympy(expr: NumericExpression):
+    if is_constant(expr):
+        return value(expr)
+    object_map, sympy_expr = sympyify_expression(expr, keep_mutable_parameters=True)
+    new_expr = sympy2pyomo_expression(sympy_expr.simplify(), object_map)
+    if is_constant(new_expr):
+        new_expr = value(new_expr)
+    return new_expr
+
+
+def simplify_with_ginac(expr: NumericExpression, ginac_interface):
+    if is_constant(expr):
+        return value(expr)
+    ginac_expr = ginac_interface.to_ginac(expr)
+    return ginac_interface.from_ginac(ginac_expr.normal())
+
+
+class Simplifier(object):
+    class Mode(NamedIntEnum):
+        auto = 0
+        sympy = 1
+        ginac = 2
+
+    def __init__(
+        self, suppress_no_ginac_warnings: bool = False, mode: Mode = Mode.auto
+    ) -> None:
+        if mode == Simplifier.Mode.auto:
+            if ginac_available:
+                mode = Simplifier.Mode.ginac
+            else:
+                if not suppress_no_ginac_warnings:
+                    msg = (
+                        "GiNaC does not seem to be available. Using SymPy. "
+                        + "Note that the GiNaC interface is significantly faster."
+                    )
+                    logging.getLogger(__name__).warning(msg)
+                    warnings.warn(msg)
+                mode = Simplifier.Mode.sympy
+
+        if mode == Simplifier.Mode.ginac:
+            self.gi = ginac_interface.GinacInterface(False)
+            self.simplify = self._simplify_with_ginac
+        else:
+            self.simplify = self._simplify_with_sympy
+
+    def _simplify_with_ginac(self, expr: NumericExpression):
+        return simplify_with_ginac(expr, self.gi)
+
+    def _simplify_with_sympy(self, expr: NumericExpression):
+        return simplify_with_sympy(expr)
diff --git a/pyomo/contrib/simplification/tests/__init__.py b/pyomo/contrib/simplification/tests/__init__.py
new file mode 100644
index 00000000000..a4a626013c4
--- /dev/null
+++ b/pyomo/contrib/simplification/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/simplification/tests/test_simplification.py b/pyomo/contrib/simplification/tests/test_simplification.py
new file mode 100644
index 00000000000..1ff9f5a3cc4
--- /dev/null
+++ b/pyomo/contrib/simplification/tests/test_simplification.py
@@ -0,0 +1,123 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+from pyomo.common import unittest
+from pyomo.common.fileutils import this_file_dir
+from pyomo.contrib.simplification import Simplifier
+from pyomo.contrib.simplification.simplify import ginac_available
+from pyomo.core.expr.compare import assertExpressionsEqual, compare_expressions
+from pyomo.core.expr.calculus.diff_with_pyomo import reverse_sd
+from pyomo.core.expr.sympy_tools import sympy_available
+
+import pyomo.environ as pe
+
+
+class SimplificationMixin:
+    def compare_against_possible_results(self, got, expected_list):
+        success = False
+        for exp in expected_list:
+            if compare_expressions(got, exp):
+                success = True
+                break
+        self.assertTrue(success)
+
+    def test_simplify(self):
+        m = pe.ConcreteModel()
+        x = m.x = pe.Var(bounds=(0, None))
+        e = x * pe.log(x)
+        der1 = reverse_sd(e)[x]
+        der2 = reverse_sd(der1)[x]
+        der2_simp = self.simp.simplify(der2)
+        expected = x**-1.0
+        assertExpressionsEqual(self, expected, der2_simp)
+
+    def test_mul(self):
+        m = pe.ConcreteModel()
+        x = m.x = pe.Var()
+        e = 2 * x
+        e2 = self.simp.simplify(e)
+        expected = 2.0 * x
+        assertExpressionsEqual(self, expected, e2)
+
+    def test_sum(self):
+        m = pe.ConcreteModel()
+        x = m.x = pe.Var()
+        e = 2 + x
+        e2 = self.simp.simplify(e)
+        self.compare_against_possible_results(e2, [2.0 + x, x + 2.0])
+
+    def test_neg(self):
+        m = pe.ConcreteModel()
+        x = m.x = pe.Var()
+        e = -pe.log(x)
+        e2 = self.simp.simplify(e)
+        self.compare_against_possible_results(
+            e2, [(-1.0) * pe.log(x), pe.log(x) * (-1.0), -pe.log(x)]
+        )
+
+    def test_pow(self):
+        m = pe.ConcreteModel()
+        x = m.x = pe.Var()
+        e = x**2.0
+        e2 = self.simp.simplify(e)
+        assertExpressionsEqual(self, e, e2)
+
+    def test_div(self):
+        m = pe.ConcreteModel()
+        x = m.x = pe.Var()
+        y = m.y = pe.Var()
+        e = x / y + y / x - x / y
+        e2 = self.simp.simplify(e)
+        self.compare_against_possible_results(
+            e2, [y / x, y * (1.0 / x), y * x**-1.0, x**-1.0 * y]
+        )
+
+    def test_unary(self):
+        m = pe.ConcreteModel()
+        x = m.x = pe.Var()
+        func_list = [pe.log, pe.sin, pe.cos, pe.tan, pe.asin, pe.acos, pe.atan]
+        for func in func_list:
+            e = func(x)
+            e2 = self.simp.simplify(e)
+            assertExpressionsEqual(self, e, e2)
+
+    def test_param(self):
+        m = pe.ConcreteModel()
+        x = m.x = pe.Var()
+        p = m.p = pe.Param(mutable=True)
+        e1 = p * x**2 + p * x + p * x**2
+        e2 = self.simp.simplify(e1)
+        self.compare_against_possible_results(
+            e2,
+            [
+                p * x**2.0 * 2.0 + p * x,
+                p * x + p * x**2.0 * 2.0,
+                2.0 * p * x**2.0 + p * x,
+                p * x + 2.0 * p * x**2.0,
+                x**2.0 * p * 2.0 + p * x,
+                p * x + x**2.0 * p * 2.0,
+                p * x * (1 + 2 * x),
+            ],
+        )
+
+
+@unittest.skipUnless(sympy_available, 'sympy is not available')
+class TestSimplificationSympy(unittest.TestCase, SimplificationMixin):
+    def setUp(self):
+        self.simp = Simplifier(mode=Simplifier.Mode.sympy)
+
+
+@unittest.pytest.mark.default
+@unittest.pytest.mark.builders
+@unittest.skipUnless(ginac_available, 'GiNaC is not available')
+class TestSimplificationGiNaC(unittest.TestCase, SimplificationMixin):
+    def setUp(self):
+        self.simp = Simplifier(mode=Simplifier.Mode.ginac)
diff --git a/pyomo/contrib/solver/__init__.py b/pyomo/contrib/solver/__init__.py
new file mode 100644
index 00000000000..a4a626013c4
--- /dev/null
+++ b/pyomo/contrib/solver/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/solver/base.py b/pyomo/contrib/solver/base.py
new file mode 100644
index 00000000000..98bf3836004
--- /dev/null
+++ b/pyomo/contrib/solver/base.py
@@ -0,0 +1,638 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import abc
+import enum
+from typing import Sequence, Dict, Optional, Mapping, NoReturn, List, Tuple
+import os
+
+from pyomo.core.base.constraint import ConstraintData
+from pyomo.core.base.var import VarData
+from pyomo.core.base.param import ParamData
+from pyomo.core.base.block import BlockData
+from pyomo.core.base.objective import Objective, ObjectiveData
+from pyomo.common.config import document_kwargs_from_configdict, ConfigValue
+from pyomo.common.errors import ApplicationError
+from pyomo.common.deprecation import deprecation_warning
+from pyomo.common.modeling import NOTSET
+from pyomo.opt.results.results_ import SolverResults as LegacySolverResults
+from pyomo.opt.results.solution import Solution as LegacySolution
+from pyomo.core.kernel.objective import minimize
+from pyomo.core.base import SymbolMap
+from pyomo.core.base.label import NumericLabeler
+from pyomo.core.staleflag import StaleFlagManager
+from pyomo.contrib.solver.config import SolverConfig, PersistentSolverConfig
+from pyomo.contrib.solver.util import get_objective
+from pyomo.contrib.solver.results import (
+    Results,
+    legacy_solver_status_map,
+    legacy_termination_condition_map,
+    legacy_solution_status_map,
+)
+
+
+class SolverBase(abc.ABC):
+    """
+    This base class defines the methods required for all solvers:
+        - available: Determines whether the solver is able to be run,
+                     combining both whether it can be found on the system and if the license is valid.
+        - solve: The main method of every solver
+        - version: The version of the solver
+        - is_persistent: Set to false for all non-persistent solvers.
+
+    Additionally, solvers should have a :attr:`config<SolverBase.config>` attribute that
+    inherits from one of :class:`SolverConfig<pyomo.contrib.solver.config.SolverConfig>`,
+    :class:`BranchAndBoundConfig<pyomo.contrib.solver.config.BranchAndBoundConfig>`,
+    :class:`PersistentSolverConfig<pyomo.contrib.solver.config.PersistentSolverConfig>`, or
+    :class:`PersistentBranchAndBoundConfig<pyomo.contrib.solver.config.PersistentBranchAndBoundConfig>`.
+    """
+
+    CONFIG = SolverConfig()
+
+    def __init__(self, **kwds) -> None:
+        # We allow the user and/or developer to name the solver something else,
+        # if they really desire.
+        # Otherwise it defaults to the name defined when the solver was registered
+        # in the SolverFactory or the class name (all lowercase), whichever is
+        # applicable
+        if "name" in kwds:
+            self.name = kwds.pop('name')
+        elif not hasattr(self, 'name'):
+            self.name = type(self).__name__.lower()
+        self.config = self.CONFIG(value=kwds)
+
+    #
+    # Support "with" statements. Forgetting to call deactivate
+    # on Plugins is a common source of memory leaks
+    #
+    def __enter__(self):
+        return self
+
+    def __exit__(self, t, v, traceback):
+        """Exit statement - enables `with` statements."""
+
+    class Availability(enum.IntEnum):
+        """
+        Class to capture different statuses in which a solver can exist in
+        order to record its availability for use.
+        """
+
+        FullLicense = 2
+        LimitedLicense = 1
+        NotFound = 0
+        BadVersion = -1
+        BadLicense = -2
+        NeedsCompiledExtension = -3
+
+        def __bool__(self):
+            return self._value_ > 0
+
+        def __format__(self, format_spec):
+            # We want general formatting of this Enum to return the
+            # formatted string value and not the int (which is the
+            # default implementation from IntEnum)
+            return format(self.name, format_spec)
+
+        def __str__(self):
+            # Note: Python 3.11 changed the core enums so that the
+            # "mixin" type for standard enums overrides the behavior
+            # specified in __format__.  We will override str() here to
+            # preserve the previous behavior
+            return self.name
+
+    @document_kwargs_from_configdict(CONFIG)
+    @abc.abstractmethod
+    def solve(self, model: BlockData, **kwargs) -> Results:
+        """
+        Solve a Pyomo model.
+
+        Parameters
+        ----------
+        model: BlockData
+            The Pyomo model to be solved
+        **kwargs
+            Additional keyword arguments (including solver_options - passthrough
+            options; delivered directly to the solver (with no validation))
+
+        Returns
+        -------
+        results: :class:`Results<pyomo.contrib.solver.results.Results>`
+            A results object
+        """
+
+    @abc.abstractmethod
+    def available(self) -> bool:
+        """Test if the solver is available on this system.
+
+        Nominally, this will return True if the solver interface is
+        valid and can be used to solve problems and False if it cannot.
+
+        Note that for licensed solvers there are a number of "levels" of
+        available: depending on the license, the solver may be available
+        with limitations on problem size or runtime (e.g., 'demo'
+        vs. 'community' vs. 'full').  In these cases, the solver may
+        return a subclass of enum.IntEnum, with members that resolve to
+        True if the solver is available (possibly with limitations).
+        The Enum may also have multiple members that all resolve to
+        False indicating the reason why the interface is not available
+        (not found, bad license, unsupported version, etc).
+
+        Returns
+        -------
+        available: SolverBase.Availability
+            An enum that indicates "how available" the solver is.
+            Note that the enum can be cast to bool, which will
+            be True if the solver is runable at all and False
+            otherwise.
+        """
+
+    @abc.abstractmethod
+    def version(self) -> Tuple:
+        """
+        Returns
+        -------
+        version: tuple
+            A tuple representing the version
+        """
+
+    def is_persistent(self) -> bool:
+        """
+        Returns
+        -------
+        is_persistent: bool
+            True if the solver is a persistent solver.
+        """
+        return False
+
+
+class PersistentSolverBase(SolverBase):
+    """
+    Base class upon which persistent solvers can be built. This inherits the
+    methods from the solver base class and adds those methods that are necessary
+    for persistent solvers.
+
+    Example usage can be seen in the Gurobi interface.
+    """
+
+    @document_kwargs_from_configdict(PersistentSolverConfig())
+    @abc.abstractmethod
+    def solve(self, model: BlockData, **kwargs) -> Results:
+        super().solve(model, kwargs)
+
+    def is_persistent(self):
+        """
+        Returns
+        -------
+        is_persistent: bool
+            True if the solver is a persistent solver.
+        """
+        return True
+
+    def _load_vars(self, vars_to_load: Optional[Sequence[VarData]] = None) -> NoReturn:
+        """
+        Load the solution of the primal variables into the value attribute of the variables.
+
+        Parameters
+        ----------
+        vars_to_load: list
+            A list of the variables whose solution should be loaded. If vars_to_load is None, then the solution
+            to all primal variables will be loaded.
+        """
+        for v, val in self._get_primals(vars_to_load=vars_to_load).items():
+            v.set_value(val, skip_validation=True)
+        StaleFlagManager.mark_all_as_stale(delayed=True)
+
+    @abc.abstractmethod
+    def _get_primals(
+        self, vars_to_load: Optional[Sequence[VarData]] = None
+    ) -> Mapping[VarData, float]:
+        """
+        Get mapping of variables to primals.
+
+        Parameters
+        ----------
+        vars_to_load : Optional[Sequence[VarData]], optional
+            Which vars to be populated into the map. The default is None.
+
+        Returns
+        -------
+        Mapping[VarData, float]
+            A map of variables to primals.
+        """
+        raise NotImplementedError(
+            f'{type(self)} does not support the get_primals method'
+        )
+
+    def _get_duals(
+        self, cons_to_load: Optional[Sequence[ConstraintData]] = None
+    ) -> Dict[ConstraintData, float]:
+        """
+        Declare sign convention in docstring here.
+
+        Parameters
+        ----------
+        cons_to_load: list
+            A list of the constraints whose duals should be loaded. If cons_to_load is None, then the duals for all
+            constraints will be loaded.
+
+        Returns
+        -------
+        duals: dict
+            Maps constraints to dual values
+        """
+        raise NotImplementedError(f'{type(self)} does not support the get_duals method')
+
+    def _get_reduced_costs(
+        self, vars_to_load: Optional[Sequence[VarData]] = None
+    ) -> Mapping[VarData, float]:
+        """
+        Parameters
+        ----------
+        vars_to_load: list
+            A list of the variables whose reduced cost should be loaded. If vars_to_load is None, then all reduced costs
+            will be loaded.
+
+        Returns
+        -------
+        reduced_costs: ComponentMap
+            Maps variable to reduced cost
+        """
+        raise NotImplementedError(
+            f'{type(self)} does not support the get_reduced_costs method'
+        )
+
+    @abc.abstractmethod
+    def set_instance(self, model):
+        """
+        Set an instance of the model
+        """
+
+    @abc.abstractmethod
+    def set_objective(self, obj: ObjectiveData):
+        """
+        Set current objective for the model
+        """
+
+    @abc.abstractmethod
+    def add_variables(self, variables: List[VarData]):
+        """
+        Add variables to the model
+        """
+
+    @abc.abstractmethod
+    def add_parameters(self, params: List[ParamData]):
+        """
+        Add parameters to the model
+        """
+
+    @abc.abstractmethod
+    def add_constraints(self, cons: List[ConstraintData]):
+        """
+        Add constraints to the model
+        """
+
+    @abc.abstractmethod
+    def add_block(self, block: BlockData):
+        """
+        Add a block to the model
+        """
+
+    @abc.abstractmethod
+    def remove_variables(self, variables: List[VarData]):
+        """
+        Remove variables from the model
+        """
+
+    @abc.abstractmethod
+    def remove_parameters(self, params: List[ParamData]):
+        """
+        Remove parameters from the model
+        """
+
+    @abc.abstractmethod
+    def remove_constraints(self, cons: List[ConstraintData]):
+        """
+        Remove constraints from the model
+        """
+
+    @abc.abstractmethod
+    def remove_block(self, block: BlockData):
+        """
+        Remove a block from the model
+        """
+
+    @abc.abstractmethod
+    def update_variables(self, variables: List[VarData]):
+        """
+        Update variables on the model
+        """
+
+    @abc.abstractmethod
+    def update_parameters(self):
+        """
+        Update parameters on the model
+        """
+
+
+class LegacySolverWrapper:
+    """
+    Class to map the new solver interface features into the legacy solver
+    interface. Necessary for backwards compatibility.
+    """
+
+    def __init__(self, **kwargs):
+        if 'solver_io' in kwargs:
+            raise NotImplementedError('Still working on this')
+        # There is no reason for a user to be trying to mix both old
+        # and new options. That is silly. So we will yell at them.
+        self.options = kwargs.pop('options', None)
+        if 'solver_options' in kwargs:
+            if self.options is not None:
+                raise ValueError(
+                    "Both 'options' and 'solver_options' were requested. "
+                    "Please use one or the other, not both."
+                )
+            self.options = kwargs.pop('solver_options')
+        super().__init__(**kwargs)
+
+    #
+    # Support "with" statements
+    #
+    def __enter__(self):
+        return self
+
+    def __exit__(self, t, v, traceback):
+        """Exit statement - enables `with` statements."""
+
+    def _map_config(
+        self,
+        tee=NOTSET,
+        load_solutions=NOTSET,
+        symbolic_solver_labels=NOTSET,
+        timelimit=NOTSET,
+        report_timing=NOTSET,
+        raise_exception_on_nonoptimal_result=NOTSET,
+        solver_io=NOTSET,
+        suffixes=NOTSET,
+        logfile=NOTSET,
+        keepfiles=NOTSET,
+        solnfile=NOTSET,
+        options=NOTSET,
+        solver_options=NOTSET,
+        writer_config=NOTSET,
+    ):
+        """Map between legacy and new interface configuration options"""
+        self.config = self.config()
+        if 'report_timing' not in self.config:
+            self.config.declare(
+                'report_timing', ConfigValue(domain=bool, default=False)
+            )
+        if tee is not NOTSET:
+            self.config.tee = tee
+        if load_solutions is not NOTSET:
+            self.config.load_solutions = load_solutions
+        if symbolic_solver_labels is not NOTSET:
+            self.config.symbolic_solver_labels = symbolic_solver_labels
+        if timelimit is not NOTSET:
+            self.config.time_limit = timelimit
+        if report_timing is not NOTSET:
+            self.config.report_timing = report_timing
+        if self.options is not None:
+            self.config.solver_options.set_value(self.options)
+        if (options is not NOTSET) and (solver_options is not NOTSET):
+            # There is no reason for a user to be trying to mix both old
+            # and new options. That is silly. So we will yell at them.
+            # Example that would raise an error:
+            # solver.solve(model, options={'foo' : 'bar'}, solver_options={'foo' : 'not_bar'})
+            raise ValueError(
+                "Both 'options' and 'solver_options' were requested. "
+                "Please use one or the other, not both."
+            )
+        elif options is not NOTSET:
+            # This block is trying to mimic the existing logic in the legacy
+            # interface that allows users to pass initialized options to
+            # the solver object and override them in the solve call.
+            self.config.solver_options.set_value(options)
+        elif solver_options is not NOTSET:
+            self.config.solver_options.set_value(solver_options)
+        if writer_config is not NOTSET:
+            self.config.writer_config.set_value(writer_config)
+        # This is a new flag in the interface. To preserve backwards compatibility,
+        # its default is set to "False"
+        if raise_exception_on_nonoptimal_result is not NOTSET:
+            self.config.raise_exception_on_nonoptimal_result = (
+                raise_exception_on_nonoptimal_result
+            )
+        if solver_io is not NOTSET and solver_io is not None:
+            raise NotImplementedError('Still working on this')
+        if suffixes is not NOTSET and suffixes is not None:
+            raise NotImplementedError('Still working on this')
+        if logfile is not NOTSET and logfile is not None:
+            raise NotImplementedError('Still working on this')
+        if keepfiles or 'keepfiles' in self.config:
+            cwd = os.getcwd()
+            deprecation_warning(
+                "`keepfiles` has been deprecated in the new solver interface. "
+                "Use `working_dir` instead to designate a directory in which files "
+                f"should be generated and saved. Setting `working_dir` to `{cwd}`.",
+                version='6.7.1',
+            )
+            self.config.working_dir = cwd
+        # I believe this currently does nothing; however, it is unclear what
+        # our desired behavior is for this.
+        if solnfile is not NOTSET:
+            if 'filename' in self.config:
+                filename = os.path.splitext(solnfile)[0]
+                self.config.filename = filename
+
+    def _map_results(self, model, results):
+        """Map between legacy and new Results objects"""
+        legacy_results = LegacySolverResults()
+        legacy_soln = LegacySolution()
+        legacy_results.solver.status = legacy_solver_status_map[
+            results.termination_condition
+        ]
+        legacy_results.solver.termination_condition = legacy_termination_condition_map[
+            results.termination_condition
+        ]
+        legacy_soln.status = legacy_solution_status_map[results.solution_status]
+        legacy_results.solver.termination_message = str(results.termination_condition)
+        legacy_results.problem.number_of_constraints = float('nan')
+        legacy_results.problem.number_of_variables = float('nan')
+        number_of_objectives = sum(
+            1
+            for _ in model.component_data_objects(
+                Objective, active=True, descend_into=True
+            )
+        )
+        legacy_results.problem.number_of_objectives = number_of_objectives
+        if number_of_objectives == 1:
+            obj = get_objective(model)
+            legacy_results.problem.sense = obj.sense
+
+            if obj.sense == minimize:
+                legacy_results.problem.lower_bound = results.objective_bound
+                legacy_results.problem.upper_bound = results.incumbent_objective
+            else:
+                legacy_results.problem.upper_bound = results.objective_bound
+                legacy_results.problem.lower_bound = results.incumbent_objective
+        if (
+            results.incumbent_objective is not None
+            and results.objective_bound is not None
+        ):
+            legacy_soln.gap = abs(results.incumbent_objective - results.objective_bound)
+        else:
+            legacy_soln.gap = None
+        return legacy_results, legacy_soln
+
+    def _solution_handler(
+        self, load_solutions, model, results, legacy_results, legacy_soln
+    ):
+        """Method to handle the preferred action for the solution"""
+        symbol_map = SymbolMap()
+        symbol_map.default_labeler = NumericLabeler('x')
+        if not hasattr(model, 'solutions'):
+            # This logic gets around Issue #2130 in which
+            # solutions is not an attribute on Blocks
+            from pyomo.core.base.PyomoModel import ModelSolutions
+
+            setattr(model, 'solutions', ModelSolutions(model))
+        model.solutions.add_symbol_map(symbol_map)
+        legacy_results._smap_id = id(symbol_map)
+        delete_legacy_soln = True
+        if load_solutions:
+            if hasattr(model, 'dual') and model.dual.import_enabled():
+                for c, val in results.solution_loader.get_duals().items():
+                    model.dual[c] = val
+            if hasattr(model, 'rc') and model.rc.import_enabled():
+                for v, val in results.solution_loader.get_reduced_costs().items():
+                    model.rc[v] = val
+        elif results.incumbent_objective is not None:
+            delete_legacy_soln = False
+            for v, val in results.solution_loader.get_primals().items():
+                legacy_soln.variable[symbol_map.getSymbol(v)] = {'Value': val}
+            if hasattr(model, 'dual') and model.dual.import_enabled():
+                for c, val in results.solution_loader.get_duals().items():
+                    legacy_soln.constraint[symbol_map.getSymbol(c)] = {'Dual': val}
+            if hasattr(model, 'rc') and model.rc.import_enabled():
+                for v, val in results.solution_loader.get_reduced_costs().items():
+                    legacy_soln.variable['Rc'] = val
+
+        legacy_results.solution.insert(legacy_soln)
+        # Timing info was not originally on the legacy results, but we want
+        # to make it accessible to folks who are utilizing the backwards
+        # compatible version.
+        legacy_results.timing_info = results.timing_info
+        if delete_legacy_soln:
+            legacy_results.solution.delete(0)
+        return legacy_results
+
+    def solve(
+        self,
+        model: BlockData,
+        tee: bool = False,
+        load_solutions: bool = True,
+        logfile: Optional[str] = None,
+        solnfile: Optional[str] = None,
+        timelimit: Optional[float] = None,
+        report_timing: bool = False,
+        solver_io: Optional[str] = None,
+        suffixes: Optional[Sequence] = None,
+        options: Optional[Dict] = None,
+        keepfiles: bool = False,
+        symbolic_solver_labels: bool = False,
+        # These are for forward-compatibility
+        raise_exception_on_nonoptimal_result: bool = False,
+        solver_options: Optional[Dict] = None,
+        writer_config: Optional[Dict] = None,
+    ):
+        """
+        Solve method: maps new solve method style to backwards compatible version.
+
+        Returns
+        -------
+        legacy_results
+            Legacy results object
+
+        """
+        original_config = self.config
+
+        map_args = (
+            'tee',
+            'load_solutions',
+            'symbolic_solver_labels',
+            'timelimit',
+            'report_timing',
+            'raise_exception_on_nonoptimal_result',
+            'solver_io',
+            'suffixes',
+            'logfile',
+            'keepfiles',
+            'solnfile',
+            'options',
+            'solver_options',
+            'writer_config',
+        )
+        loc = locals()
+        filtered_args = {k: loc[k] for k in map_args if loc.get(k, None) is not None}
+        self._map_config(**filtered_args)
+
+        results: Results = super().solve(model)
+        legacy_results, legacy_soln = self._map_results(model, results)
+        legacy_results = self._solution_handler(
+            load_solutions, model, results, legacy_results, legacy_soln
+        )
+
+        if self.config.report_timing:
+            print(results.timing_info.timer)
+
+        self.config = original_config
+
+        return legacy_results
+
+    def available(self, exception_flag=True):
+        """
+        Returns a bool determining whether the requested solver is available
+        on the system.
+        """
+        ans = super().available()
+        if exception_flag and not ans:
+            raise ApplicationError(
+                f'Solver "{self.name}" is not available. '
+                f'The returned status is: {ans}.'
+            )
+        return bool(ans)
+
+    def license_is_valid(self) -> bool:
+        """Test if the solver license is valid on this system.
+
+        Note that this method is included for compatibility with the
+        legacy SolverFactory interface.  Unlicensed or open source
+        solvers will return True by definition.  Licensed solvers will
+        return True if a valid license is found.
+
+        Returns
+        -------
+        available: bool
+            True if the solver license is valid. Otherwise, False.
+
+        """
+        return bool(self.available())
+
+    def config_block(self, init=False):
+        from pyomo.scripting.solve_config import default_config_block
+
+        return default_config_block(self, init)[0]
+
+    def set_options(self, options):
+        opts = {k: v for k, v in options.value().items() if v is not None}
+        if opts:
+            self._map_config(**opts)
diff --git a/pyomo/contrib/solver/config.py b/pyomo/contrib/solver/config.py
new file mode 100644
index 00000000000..e60219a74b5
--- /dev/null
+++ b/pyomo/contrib/solver/config.py
@@ -0,0 +1,406 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import io
+import logging
+import sys
+
+from collections.abc import Sequence
+from typing import Optional, List, TextIO
+
+from pyomo.common.config import (
+    ConfigDict,
+    ConfigValue,
+    NonNegativeFloat,
+    NonNegativeInt,
+    ADVANCED_OPTION,
+    Bool,
+    Path,
+)
+from pyomo.common.log import LogStream
+from pyomo.common.numeric_types import native_logical_types
+from pyomo.common.timing import HierarchicalTimer
+
+
+def TextIO_or_Logger(val):
+    ans = []
+    if not isinstance(val, Sequence):
+        val = [val]
+    for v in val:
+        if v.__class__ in native_logical_types:
+            if v:
+                ans.append(sys.stdout)
+        elif isinstance(v, io.TextIOBase):
+            ans.append(v)
+        elif isinstance(v, logging.Logger):
+            ans.append(LogStream(level=logging.INFO, logger=v))
+        else:
+            raise ValueError(
+                "Expected bool, TextIOBase, or Logger, but received {v.__class__}"
+            )
+    return ans
+
+
+class SolverConfig(ConfigDict):
+    """
+    Base config for all direct solver interfaces
+    """
+
+    def __init__(
+        self,
+        description=None,
+        doc=None,
+        implicit=False,
+        implicit_domain=None,
+        visibility=0,
+    ):
+        super().__init__(
+            description=description,
+            doc=doc,
+            implicit=implicit,
+            implicit_domain=implicit_domain,
+            visibility=visibility,
+        )
+
+        self.tee: List[TextIO] = self.declare(
+            'tee',
+            ConfigValue(
+                domain=TextIO_or_Logger,
+                default=False,
+                description="""``tee`` accepts :py:class:`bool`,
+                :py:class:`io.TextIOBase`, or :py:class:`logging.Logger`
+                (or a list of these types).  ``True`` is mapped to
+                ``sys.stdout``.  The solver log will be printed to each of
+                these streams / destinations.""",
+            ),
+        )
+        self.working_dir: Optional[Path] = self.declare(
+            'working_dir',
+            ConfigValue(
+                domain=Path(),
+                default=None,
+                description="The directory in which generated files should be saved. "
+                "This replaces the `keepfiles` option.",
+            ),
+        )
+        self.load_solutions: bool = self.declare(
+            'load_solutions',
+            ConfigValue(
+                domain=Bool,
+                default=True,
+                description="If True, the values of the primal variables will be loaded into the model.",
+            ),
+        )
+        self.raise_exception_on_nonoptimal_result: bool = self.declare(
+            'raise_exception_on_nonoptimal_result',
+            ConfigValue(
+                domain=Bool,
+                default=True,
+                description="If False, the `solve` method will continue processing "
+                "even if the returned result is nonoptimal.",
+            ),
+        )
+        self.symbolic_solver_labels: bool = self.declare(
+            'symbolic_solver_labels',
+            ConfigValue(
+                domain=Bool,
+                default=False,
+                description="If True, the names given to the solver will reflect the names of the Pyomo components. "
+                "Cannot be changed after set_instance is called.",
+            ),
+        )
+        self.timer: Optional[HierarchicalTimer] = self.declare(
+            'timer',
+            ConfigValue(
+                default=None,
+                description="A timer object for recording relevant process timing data.",
+            ),
+        )
+        self.threads: Optional[int] = self.declare(
+            'threads',
+            ConfigValue(
+                domain=NonNegativeInt,
+                description="Number of threads to be used by a solver.",
+                default=None,
+            ),
+        )
+        self.time_limit: Optional[float] = self.declare(
+            'time_limit',
+            ConfigValue(
+                domain=NonNegativeFloat,
+                description="Time limit applied to the solver (in seconds).",
+            ),
+        )
+        self.solver_options: ConfigDict = self.declare(
+            'solver_options',
+            ConfigDict(implicit=True, description="Options to pass to the solver."),
+        )
+
+
+class BranchAndBoundConfig(SolverConfig):
+    """
+    Base config for all direct MIP solver interfaces
+
+    Attributes
+    ----------
+    rel_gap: float
+        The relative value of the gap in relation to the best bound
+    abs_gap: float
+        The absolute value of the difference between the incumbent and best bound
+    """
+
+    def __init__(
+        self,
+        description=None,
+        doc=None,
+        implicit=False,
+        implicit_domain=None,
+        visibility=0,
+    ):
+        super().__init__(
+            description=description,
+            doc=doc,
+            implicit=implicit,
+            implicit_domain=implicit_domain,
+            visibility=visibility,
+        )
+
+        self.rel_gap: Optional[float] = self.declare(
+            'rel_gap',
+            ConfigValue(
+                domain=NonNegativeFloat,
+                description="Optional termination condition; the relative value of the "
+                "gap in relation to the best bound",
+            ),
+        )
+        self.abs_gap: Optional[float] = self.declare(
+            'abs_gap',
+            ConfigValue(
+                domain=NonNegativeFloat,
+                description="Optional termination condition; the absolute value of the "
+                "difference between the incumbent and best bound",
+            ),
+        )
+
+
+class AutoUpdateConfig(ConfigDict):
+    """
+    This is necessary for persistent solvers.
+
+    Attributes
+    ----------
+    check_for_new_or_removed_constraints: bool
+    check_for_new_or_removed_vars: bool
+    check_for_new_or_removed_params: bool
+    check_for_new_objective: bool
+    update_constraints: bool
+    update_vars: bool
+    update_parameters: bool
+    update_named_expressions: bool
+    update_objective: bool
+    treat_fixed_vars_as_params: bool
+    """
+
+    def __init__(
+        self,
+        description=None,
+        doc=None,
+        implicit=False,
+        implicit_domain=None,
+        visibility=0,
+    ):
+        if doc is None:
+            doc = 'Configuration options to detect changes in model between solves'
+        super().__init__(
+            description=description,
+            doc=doc,
+            implicit=implicit,
+            implicit_domain=implicit_domain,
+            visibility=visibility,
+        )
+
+        self.check_for_new_or_removed_constraints: bool = self.declare(
+            'check_for_new_or_removed_constraints',
+            ConfigValue(
+                domain=bool,
+                default=True,
+                description="""
+                If False, new/old constraints will not be automatically detected on subsequent
+                solves. Use False only when manually updating the solver with opt.add_constraints()
+                and opt.remove_constraints() or when you are certain constraints are not being
+                added to/removed from the model.""",
+            ),
+        )
+        self.check_for_new_or_removed_vars: bool = self.declare(
+            'check_for_new_or_removed_vars',
+            ConfigValue(
+                domain=bool,
+                default=True,
+                description="""
+                If False, new/old variables will not be automatically detected on subsequent 
+                solves. Use False only when manually updating the solver with opt.add_variables() and 
+                opt.remove_variables() or when you are certain variables are not being added to /
+                removed from the model.""",
+            ),
+        )
+        self.check_for_new_or_removed_params: bool = self.declare(
+            'check_for_new_or_removed_params',
+            ConfigValue(
+                domain=bool,
+                default=True,
+                description="""
+                If False, new/old parameters will not be automatically detected on subsequent 
+                solves. Use False only when manually updating the solver with opt.add_parameters() and 
+                opt.remove_parameters() or when you are certain parameters are not being added to /
+                removed from the model.""",
+            ),
+        )
+        self.check_for_new_objective: bool = self.declare(
+            'check_for_new_objective',
+            ConfigValue(
+                domain=bool,
+                default=True,
+                description="""
+                If False, new/old objectives will not be automatically detected on subsequent 
+                solves. Use False only when manually updating the solver with opt.set_objective() or 
+                when you are certain objectives are not being added to / removed from the model.""",
+            ),
+        )
+        self.update_constraints: bool = self.declare(
+            'update_constraints',
+            ConfigValue(
+                domain=bool,
+                default=True,
+                description="""
+                If False, changes to existing constraints will not be automatically detected on 
+                subsequent solves. This includes changes to the lower, body, and upper attributes of 
+                constraints. Use False only when manually updating the solver with 
+                opt.remove_constraints() and opt.add_constraints() or when you are certain constraints 
+                are not being modified.""",
+            ),
+        )
+        self.update_vars: bool = self.declare(
+            'update_vars',
+            ConfigValue(
+                domain=bool,
+                default=True,
+                description="""
+                If False, changes to existing variables will not be automatically detected on 
+                subsequent solves. This includes changes to the lb, ub, domain, and fixed 
+                attributes of variables. Use False only when manually updating the solver with 
+                opt.update_variables() or when you are certain variables are not being modified.""",
+            ),
+        )
+        self.update_parameters: bool = self.declare(
+            'update_parameters',
+            ConfigValue(
+                domain=bool,
+                default=True,
+                description="""
+                If False, changes to parameter values will not be automatically detected on 
+                subsequent solves. Use False only when manually updating the solver with 
+                opt.update_parameters() or when you are certain parameters are not being modified.""",
+            ),
+        )
+        self.update_named_expressions: bool = self.declare(
+            'update_named_expressions',
+            ConfigValue(
+                domain=bool,
+                default=True,
+                description="""
+                If False, changes to Expressions will not be automatically detected on 
+                subsequent solves. Use False only when manually updating the solver with 
+                opt.remove_constraints() and opt.add_constraints() or when you are certain 
+                Expressions are not being modified.""",
+            ),
+        )
+        self.update_objective: bool = self.declare(
+            'update_objective',
+            ConfigValue(
+                domain=bool,
+                default=True,
+                description="""
+                If False, changes to objectives will not be automatically detected on 
+                subsequent solves. This includes the expr and sense attributes of objectives. Use 
+                False only when manually updating the solver with opt.set_objective() or when you are 
+                certain objectives are not being modified.""",
+            ),
+        )
+        self.treat_fixed_vars_as_params: bool = self.declare(
+            'treat_fixed_vars_as_params',
+            ConfigValue(
+                domain=bool,
+                default=True,
+                visibility=ADVANCED_OPTION,
+                description="""
+                This is an advanced option that should only be used in special circumstances. 
+                With the default setting of True, fixed variables will be treated like parameters. 
+                This means that z == x*y will be linear if x or y is fixed and the constraint 
+                can be written to an LP file. If the value of the fixed variable gets changed, we have 
+                to completely reprocess all constraints using that variable. If 
+                treat_fixed_vars_as_params is False, then constraints will be processed as if fixed 
+                variables are not fixed, and the solver will be told the variable is fixed. This means 
+                z == x*y could not be written to an LP file even if x and/or y is fixed. However, 
+                updating the values of fixed variables is much faster this way.""",
+            ),
+        )
+
+
+class PersistentSolverConfig(SolverConfig):
+    """
+    Base config for all persistent solver interfaces
+    """
+
+    def __init__(
+        self,
+        description=None,
+        doc=None,
+        implicit=False,
+        implicit_domain=None,
+        visibility=0,
+    ):
+        super().__init__(
+            description=description,
+            doc=doc,
+            implicit=implicit,
+            implicit_domain=implicit_domain,
+            visibility=visibility,
+        )
+
+        self.auto_updates: AutoUpdateConfig = self.declare(
+            'auto_updates', AutoUpdateConfig()
+        )
+
+
+class PersistentBranchAndBoundConfig(BranchAndBoundConfig):
+    """
+    Base config for all persistent MIP solver interfaces
+    """
+
+    def __init__(
+        self,
+        description=None,
+        doc=None,
+        implicit=False,
+        implicit_domain=None,
+        visibility=0,
+    ):
+        super().__init__(
+            description=description,
+            doc=doc,
+            implicit=implicit,
+            implicit_domain=implicit_domain,
+            visibility=visibility,
+        )
+
+        self.auto_updates: AutoUpdateConfig = self.declare(
+            'auto_updates', AutoUpdateConfig()
+        )
diff --git a/pyomo/contrib/solver/factory.py b/pyomo/contrib/solver/factory.py
new file mode 100644
index 00000000000..d3ca1329af3
--- /dev/null
+++ b/pyomo/contrib/solver/factory.py
@@ -0,0 +1,41 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+
+from pyomo.opt.base.solvers import LegacySolverFactory
+from pyomo.common.factory import Factory
+from pyomo.contrib.solver.base import LegacySolverWrapper
+
+
+class SolverFactoryClass(Factory):
+    def register(self, name, legacy_name=None, doc=None):
+        if legacy_name is None:
+            legacy_name = name
+
+        def decorator(cls):
+            self._cls[name] = cls
+            self._doc[name] = doc
+
+            class LegacySolver(LegacySolverWrapper, cls):
+                pass
+
+            LegacySolverFactory.register(legacy_name, doc + " (new interface)")(
+                LegacySolver
+            )
+
+            # Preserve the preferred name, as registered in the Factory
+            cls.name = name
+            return cls
+
+        return decorator
+
+
+SolverFactory = SolverFactoryClass()
diff --git a/pyomo/contrib/solver/gurobi.py b/pyomo/contrib/solver/gurobi.py
new file mode 100644
index 00000000000..10d8120c8b3
--- /dev/null
+++ b/pyomo/contrib/solver/gurobi.py
@@ -0,0 +1,1505 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+from collections.abc import Iterable
+import logging
+import math
+from typing import List, Optional
+from pyomo.common.collections import ComponentSet, ComponentMap, OrderedSet
+from pyomo.common.dependencies import attempt_import
+from pyomo.common.errors import PyomoException
+from pyomo.common.tee import capture_output, TeeStream
+from pyomo.common.timing import HierarchicalTimer
+from pyomo.common.shutdown import python_is_shutting_down
+from pyomo.common.config import ConfigValue
+from pyomo.core.kernel.objective import minimize, maximize
+from pyomo.core.base import SymbolMap, NumericLabeler, TextLabeler
+from pyomo.core.base.var import VarData
+from pyomo.core.base.constraint import ConstraintData
+from pyomo.core.base.sos import SOSConstraintData
+from pyomo.core.base.param import ParamData
+from pyomo.core.expr.numvalue import value, is_constant, is_fixed, native_numeric_types
+from pyomo.repn import generate_standard_repn
+from pyomo.core.expr.numeric_expr import NPV_MaxExpression, NPV_MinExpression
+from pyomo.contrib.solver.base import PersistentSolverBase
+from pyomo.contrib.solver.results import Results, TerminationCondition, SolutionStatus
+from pyomo.contrib.solver.config import PersistentBranchAndBoundConfig
+from pyomo.contrib.solver.persistent import PersistentSolverUtils
+from pyomo.contrib.solver.solution import PersistentSolutionLoader
+from pyomo.core.staleflag import StaleFlagManager
+import sys
+import datetime
+import io
+
+logger = logging.getLogger(__name__)
+
+
+def _import_gurobipy():
+    try:
+        import gurobipy
+    except ImportError:
+        Gurobi._available = Gurobi.Availability.NotFound
+        raise
+    if gurobipy.GRB.VERSION_MAJOR < 7:
+        Gurobi._available = Gurobi.Availability.BadVersion
+        raise ImportError('The APPSI Gurobi interface requires gurobipy>=7.0.0')
+    return gurobipy
+
+
+gurobipy, gurobipy_available = attempt_import('gurobipy', importer=_import_gurobipy)
+
+
+class DegreeError(PyomoException):
+    pass
+
+
+class GurobiConfig(PersistentBranchAndBoundConfig):
+    def __init__(
+        self,
+        description=None,
+        doc=None,
+        implicit=False,
+        implicit_domain=None,
+        visibility=0,
+    ):
+        super(GurobiConfig, self).__init__(
+            description=description,
+            doc=doc,
+            implicit=implicit,
+            implicit_domain=implicit_domain,
+            visibility=visibility,
+        )
+        self.use_mipstart: bool = self.declare(
+            'use_mipstart',
+            ConfigValue(
+                default=False,
+                domain=bool,
+                description="If True, the values of the integer variables will be passed to Gurobi.",
+            ),
+        )
+
+
+class GurobiSolutionLoader(PersistentSolutionLoader):
+    def load_vars(self, vars_to_load=None, solution_number=0):
+        self._assert_solution_still_valid()
+        self._solver._load_vars(
+            vars_to_load=vars_to_load, solution_number=solution_number
+        )
+
+    def get_primals(self, vars_to_load=None, solution_number=0):
+        self._assert_solution_still_valid()
+        return self._solver._get_primals(
+            vars_to_load=vars_to_load, solution_number=solution_number
+        )
+
+
+class _MutableLowerBound(object):
+    def __init__(self, expr):
+        self.var = None
+        self.expr = expr
+
+    def update(self):
+        self.var.setAttr('lb', value(self.expr))
+
+
+class _MutableUpperBound(object):
+    def __init__(self, expr):
+        self.var = None
+        self.expr = expr
+
+    def update(self):
+        self.var.setAttr('ub', value(self.expr))
+
+
+class _MutableLinearCoefficient(object):
+    def __init__(self):
+        self.expr = None
+        self.var = None
+        self.con = None
+        self.gurobi_model = None
+
+    def update(self):
+        self.gurobi_model.chgCoeff(self.con, self.var, value(self.expr))
+
+
+class _MutableRangeConstant(object):
+    def __init__(self):
+        self.lhs_expr = None
+        self.rhs_expr = None
+        self.con = None
+        self.slack_name = None
+        self.gurobi_model = None
+
+    def update(self):
+        rhs_val = value(self.rhs_expr)
+        lhs_val = value(self.lhs_expr)
+        self.con.rhs = rhs_val
+        slack = self.gurobi_model.getVarByName(self.slack_name)
+        slack.ub = rhs_val - lhs_val
+
+
+class _MutableConstant(object):
+    def __init__(self):
+        self.expr = None
+        self.con = None
+
+    def update(self):
+        self.con.rhs = value(self.expr)
+
+
+class _MutableQuadraticConstraint(object):
+    def __init__(
+        self, gurobi_model, gurobi_con, constant, linear_coefs, quadratic_coefs
+    ):
+        self.con = gurobi_con
+        self.gurobi_model = gurobi_model
+        self.constant = constant
+        self.last_constant_value = value(self.constant.expr)
+        self.linear_coefs = linear_coefs
+        self.last_linear_coef_values = [value(i.expr) for i in self.linear_coefs]
+        self.quadratic_coefs = quadratic_coefs
+        self.last_quadratic_coef_values = [value(i.expr) for i in self.quadratic_coefs]
+
+    def get_updated_expression(self):
+        gurobi_expr = self.gurobi_model.getQCRow(self.con)
+        for ndx, coef in enumerate(self.linear_coefs):
+            current_coef_value = value(coef.expr)
+            incremental_coef_value = (
+                current_coef_value - self.last_linear_coef_values[ndx]
+            )
+            gurobi_expr += incremental_coef_value * coef.var
+            self.last_linear_coef_values[ndx] = current_coef_value
+        for ndx, coef in enumerate(self.quadratic_coefs):
+            current_coef_value = value(coef.expr)
+            incremental_coef_value = (
+                current_coef_value - self.last_quadratic_coef_values[ndx]
+            )
+            gurobi_expr += incremental_coef_value * coef.var1 * coef.var2
+            self.last_quadratic_coef_values[ndx] = current_coef_value
+        return gurobi_expr
+
+    def get_updated_rhs(self):
+        return value(self.constant.expr)
+
+
+class _MutableObjective(object):
+    def __init__(self, gurobi_model, constant, linear_coefs, quadratic_coefs):
+        self.gurobi_model = gurobi_model
+        self.constant = constant
+        self.linear_coefs = linear_coefs
+        self.quadratic_coefs = quadratic_coefs
+        self.last_quadratic_coef_values = [value(i.expr) for i in self.quadratic_coefs]
+
+    def get_updated_expression(self):
+        for ndx, coef in enumerate(self.linear_coefs):
+            coef.var.obj = value(coef.expr)
+        self.gurobi_model.ObjCon = value(self.constant.expr)
+
+        gurobi_expr = None
+        for ndx, coef in enumerate(self.quadratic_coefs):
+            if value(coef.expr) != self.last_quadratic_coef_values[ndx]:
+                if gurobi_expr is None:
+                    self.gurobi_model.update()
+                    gurobi_expr = self.gurobi_model.getObjective()
+                current_coef_value = value(coef.expr)
+                incremental_coef_value = (
+                    current_coef_value - self.last_quadratic_coef_values[ndx]
+                )
+                gurobi_expr += incremental_coef_value * coef.var1 * coef.var2
+                self.last_quadratic_coef_values[ndx] = current_coef_value
+        return gurobi_expr
+
+
+class _MutableQuadraticCoefficient(object):
+    def __init__(self):
+        self.expr = None
+        self.var1 = None
+        self.var2 = None
+
+
+class Gurobi(PersistentSolverUtils, PersistentSolverBase):
+    """
+    Interface to Gurobi
+    """
+
+    CONFIG = GurobiConfig()
+
+    _available = None
+    _num_instances = 0
+
+    def __init__(self, **kwds):
+        PersistentSolverUtils.__init__(self)
+        PersistentSolverBase.__init__(self, **kwds)
+        Gurobi._num_instances += 1
+        self._solver_model = None
+        self._symbol_map = SymbolMap()
+        self._labeler = None
+        self._pyomo_var_to_solver_var_map = dict()
+        self._pyomo_con_to_solver_con_map = dict()
+        self._solver_con_to_pyomo_con_map = dict()
+        self._pyomo_sos_to_solver_sos_map = dict()
+        self._range_constraints = OrderedSet()
+        self._mutable_helpers = dict()
+        self._mutable_bounds = dict()
+        self._mutable_quadratic_helpers = dict()
+        self._mutable_objective = None
+        self._needs_updated = True
+        self._callback = None
+        self._callback_func = None
+        self._constraints_added_since_update = OrderedSet()
+        self._vars_added_since_update = ComponentSet()
+        self._last_results_object: Optional[Results] = None
+        self._config: Optional[GurobiConfig] = None
+
+    def available(self):
+        if not gurobipy_available:  # this triggers the deferred import
+            return self.Availability.NotFound
+        elif self._available == self.Availability.BadVersion:
+            return self.Availability.BadVersion
+        else:
+            return self._check_license()
+
+    def _check_license(self):
+        avail = False
+        try:
+            # Gurobipy writes out license file information when creating
+            # the environment
+            with capture_output(capture_fd=True):
+                m = gurobipy.Model()
+            if self._solver_model is None:
+                self._solver_model = m
+            avail = True
+        except gurobipy.GurobiError:
+            avail = False
+
+        if avail:
+            if self._available is None:
+                self._available = Gurobi._check_full_license()
+            return self._available
+        else:
+            return self.Availability.BadLicense
+
+    @classmethod
+    def _check_full_license(cls):
+        m = gurobipy.Model()
+        m.setParam('OutputFlag', 0)
+        try:
+            m.addVars(range(2001))
+            m.optimize()
+            return cls.Availability.FullLicense
+        except gurobipy.GurobiError:
+            return cls.Availability.LimitedLicense
+
+    def release_license(self):
+        self._reinit()
+        if gurobipy_available:
+            with capture_output(capture_fd=True):
+                gurobipy.disposeDefaultEnv()
+
+    def __del__(self):
+        if not python_is_shutting_down():
+            Gurobi._num_instances -= 1
+            if Gurobi._num_instances == 0:
+                self.release_license()
+
+    def version(self):
+        version = (
+            gurobipy.GRB.VERSION_MAJOR,
+            gurobipy.GRB.VERSION_MINOR,
+            gurobipy.GRB.VERSION_TECHNICAL,
+        )
+        return version
+
+    @property
+    def symbol_map(self):
+        return self._symbol_map
+
+    def _solve(self):
+        config = self._config
+        timer = config.timer
+        ostreams = [io.StringIO()] + config.tee
+
+        with TeeStream(*ostreams) as t, capture_output(t.STDOUT, capture_fd=False):
+            options = config.solver_options
+
+            self._solver_model.setParam('LogToConsole', 1)
+
+            if config.threads is not None:
+                self._solver_model.setParam('Threads', config.threads)
+            if config.time_limit is not None:
+                self._solver_model.setParam('TimeLimit', config.time_limit)
+            if config.rel_gap is not None:
+                self._solver_model.setParam('MIPGap', config.rel_gap)
+            if config.abs_gap is not None:
+                self._solver_model.setParam('MIPGapAbs', config.abs_gap)
+
+            if config.use_mipstart:
+                for (
+                    pyomo_var_id,
+                    gurobi_var,
+                ) in self._pyomo_var_to_solver_var_map.items():
+                    pyomo_var = self._vars[pyomo_var_id][0]
+                    if pyomo_var.is_integer() and pyomo_var.value is not None:
+                        self.set_var_attr(pyomo_var, 'Start', pyomo_var.value)
+
+            for key, option in options.items():
+                self._solver_model.setParam(key, option)
+
+            timer.start('optimize')
+            self._solver_model.optimize(self._callback)
+            timer.stop('optimize')
+
+        self._needs_updated = False
+        res = self._postsolve(timer)
+        res.solver_configuration = config
+        res.solver_name = 'Gurobi'
+        res.solver_version = self.version()
+        res.solver_log = ostreams[0].getvalue()
+        return res
+
+    def solve(self, model, **kwds) -> Results:
+        start_timestamp = datetime.datetime.now(datetime.timezone.utc)
+        self._config = config = self.config(value=kwds, preserve_implicit=True)
+        StaleFlagManager.mark_all_as_stale()
+        # Note: solver availability check happens in set_instance(),
+        # which will be called (either by the user before this call, or
+        # below) before this method calls self._solve.
+        if self._last_results_object is not None:
+            self._last_results_object.solution_loader.invalidate()
+        if config.timer is None:
+            config.timer = HierarchicalTimer()
+        timer = config.timer
+        if model is not self._model:
+            timer.start('set_instance')
+            self.set_instance(model)
+            timer.stop('set_instance')
+        else:
+            timer.start('update')
+            self.update(timer=timer)
+            timer.stop('update')
+        res = self._solve()
+        self._last_results_object = res
+        end_timestamp = datetime.datetime.now(datetime.timezone.utc)
+        res.timing_info.start_timestamp = start_timestamp
+        res.timing_info.wall_time = (end_timestamp - start_timestamp).total_seconds()
+        res.timing_info.timer = timer
+        return res
+
+    def _process_domain_and_bounds(
+        self, var, var_id, mutable_lbs, mutable_ubs, ndx, gurobipy_var
+    ):
+        _v, _lb, _ub, _fixed, _domain_interval, _value = self._vars[id(var)]
+        lb, ub, step = _domain_interval
+        if lb is None:
+            lb = -gurobipy.GRB.INFINITY
+        if ub is None:
+            ub = gurobipy.GRB.INFINITY
+        if step == 0:
+            vtype = gurobipy.GRB.CONTINUOUS
+        elif step == 1:
+            if lb == 0 and ub == 1:
+                vtype = gurobipy.GRB.BINARY
+            else:
+                vtype = gurobipy.GRB.INTEGER
+        else:
+            raise ValueError(
+                f'Unrecognized domain step: {step} (should be either 0 or 1)'
+            )
+        if _fixed:
+            lb = _value
+            ub = _value
+        else:
+            if _lb is not None:
+                if not is_constant(_lb):
+                    mutable_bound = _MutableLowerBound(NPV_MaxExpression((_lb, lb)))
+                    if gurobipy_var is None:
+                        mutable_lbs[ndx] = mutable_bound
+                    else:
+                        mutable_bound.var = gurobipy_var
+                    self._mutable_bounds[var_id, 'lb'] = (var, mutable_bound)
+                lb = max(value(_lb), lb)
+            if _ub is not None:
+                if not is_constant(_ub):
+                    mutable_bound = _MutableUpperBound(NPV_MinExpression((_ub, ub)))
+                    if gurobipy_var is None:
+                        mutable_ubs[ndx] = mutable_bound
+                    else:
+                        mutable_bound.var = gurobipy_var
+                    self._mutable_bounds[var_id, 'ub'] = (var, mutable_bound)
+                ub = min(value(_ub), ub)
+
+        return lb, ub, vtype
+
+    def _add_variables(self, variables: List[VarData]):
+        var_names = list()
+        vtypes = list()
+        lbs = list()
+        ubs = list()
+        mutable_lbs = dict()
+        mutable_ubs = dict()
+        for ndx, var in enumerate(variables):
+            varname = self._symbol_map.getSymbol(var, self._labeler)
+            lb, ub, vtype = self._process_domain_and_bounds(
+                var, id(var), mutable_lbs, mutable_ubs, ndx, None
+            )
+            var_names.append(varname)
+            vtypes.append(vtype)
+            lbs.append(lb)
+            ubs.append(ub)
+
+        gurobi_vars = self._solver_model.addVars(
+            len(variables), lb=lbs, ub=ubs, vtype=vtypes, name=var_names
+        )
+
+        for ndx, pyomo_var in enumerate(variables):
+            gurobi_var = gurobi_vars[ndx]
+            self._pyomo_var_to_solver_var_map[id(pyomo_var)] = gurobi_var
+        for ndx, mutable_bound in mutable_lbs.items():
+            mutable_bound.var = gurobi_vars[ndx]
+        for ndx, mutable_bound in mutable_ubs.items():
+            mutable_bound.var = gurobi_vars[ndx]
+        self._vars_added_since_update.update(variables)
+        self._needs_updated = True
+
+    def _add_parameters(self, params: List[ParamData]):
+        pass
+
+    def _reinit(self):
+        saved_config = self.config
+        saved_tmp_config = self._config
+        self.__init__()
+        self.config = saved_config
+        self._config = saved_tmp_config
+
+    def set_instance(self, model):
+        if self._last_results_object is not None:
+            self._last_results_object.solution_loader.invalidate()
+        if not self.available():
+            c = self.__class__
+            raise PyomoException(
+                f'Solver {c.__module__}.{c.__qualname__} is not available '
+                f'({self.available()}).'
+            )
+        self._reinit()
+        self._model = model
+
+        if self.config.symbolic_solver_labels:
+            self._labeler = TextLabeler()
+        else:
+            self._labeler = NumericLabeler('x')
+
+        if model.name is not None:
+            self._solver_model = gurobipy.Model(model.name)
+        else:
+            self._solver_model = gurobipy.Model()
+
+        self.add_block(model)
+        if self._objective is None:
+            self.set_objective(None)
+
+    def _get_expr_from_pyomo_expr(self, expr):
+        mutable_linear_coefficients = list()
+        mutable_quadratic_coefficients = list()
+        repn = generate_standard_repn(expr, quadratic=True, compute_values=False)
+
+        degree = repn.polynomial_degree()
+        if (degree is None) or (degree > 2):
+            raise DegreeError(
+                'GurobiAuto does not support expressions of degree {0}.'.format(degree)
+            )
+
+        if len(repn.linear_vars) > 0:
+            linear_coef_vals = list()
+            for ndx, coef in enumerate(repn.linear_coefs):
+                if not is_constant(coef):
+                    mutable_linear_coefficient = _MutableLinearCoefficient()
+                    mutable_linear_coefficient.expr = coef
+                    mutable_linear_coefficient.var = self._pyomo_var_to_solver_var_map[
+                        id(repn.linear_vars[ndx])
+                    ]
+                    mutable_linear_coefficients.append(mutable_linear_coefficient)
+                linear_coef_vals.append(value(coef))
+            new_expr = gurobipy.LinExpr(
+                linear_coef_vals,
+                [self._pyomo_var_to_solver_var_map[id(i)] for i in repn.linear_vars],
+            )
+        else:
+            new_expr = 0.0
+
+        for ndx, v in enumerate(repn.quadratic_vars):
+            x, y = v
+            gurobi_x = self._pyomo_var_to_solver_var_map[id(x)]
+            gurobi_y = self._pyomo_var_to_solver_var_map[id(y)]
+            coef = repn.quadratic_coefs[ndx]
+            if not is_constant(coef):
+                mutable_quadratic_coefficient = _MutableQuadraticCoefficient()
+                mutable_quadratic_coefficient.expr = coef
+                mutable_quadratic_coefficient.var1 = gurobi_x
+                mutable_quadratic_coefficient.var2 = gurobi_y
+                mutable_quadratic_coefficients.append(mutable_quadratic_coefficient)
+            coef_val = value(coef)
+            new_expr += coef_val * gurobi_x * gurobi_y
+
+        return (
+            new_expr,
+            repn.constant,
+            mutable_linear_coefficients,
+            mutable_quadratic_coefficients,
+        )
+
+    def _add_constraints(self, cons: List[ConstraintData]):
+        for con in cons:
+            conname = self._symbol_map.getSymbol(con, self._labeler)
+            (
+                gurobi_expr,
+                repn_constant,
+                mutable_linear_coefficients,
+                mutable_quadratic_coefficients,
+            ) = self._get_expr_from_pyomo_expr(con.body)
+
+            if (
+                gurobi_expr.__class__ in {gurobipy.LinExpr, gurobipy.Var}
+                or gurobi_expr.__class__ in native_numeric_types
+            ):
+                if con.equality:
+                    rhs_expr = con.lower - repn_constant
+                    rhs_val = value(rhs_expr)
+                    gurobipy_con = self._solver_model.addLConstr(
+                        gurobi_expr, gurobipy.GRB.EQUAL, rhs_val, name=conname
+                    )
+                    if not is_constant(rhs_expr):
+                        mutable_constant = _MutableConstant()
+                        mutable_constant.expr = rhs_expr
+                        mutable_constant.con = gurobipy_con
+                        self._mutable_helpers[con] = [mutable_constant]
+                elif con.has_lb() and con.has_ub():
+                    lhs_expr = con.lower - repn_constant
+                    rhs_expr = con.upper - repn_constant
+                    lhs_val = value(lhs_expr)
+                    rhs_val = value(rhs_expr)
+                    gurobipy_con = self._solver_model.addRange(
+                        gurobi_expr, lhs_val, rhs_val, name=conname
+                    )
+                    self._range_constraints.add(con)
+                    if not is_constant(lhs_expr) or not is_constant(rhs_expr):
+                        mutable_range_constant = _MutableRangeConstant()
+                        mutable_range_constant.lhs_expr = lhs_expr
+                        mutable_range_constant.rhs_expr = rhs_expr
+                        mutable_range_constant.con = gurobipy_con
+                        mutable_range_constant.slack_name = 'Rg' + conname
+                        mutable_range_constant.gurobi_model = self._solver_model
+                        self._mutable_helpers[con] = [mutable_range_constant]
+                elif con.has_lb():
+                    rhs_expr = con.lower - repn_constant
+                    rhs_val = value(rhs_expr)
+                    gurobipy_con = self._solver_model.addLConstr(
+                        gurobi_expr, gurobipy.GRB.GREATER_EQUAL, rhs_val, name=conname
+                    )
+                    if not is_constant(rhs_expr):
+                        mutable_constant = _MutableConstant()
+                        mutable_constant.expr = rhs_expr
+                        mutable_constant.con = gurobipy_con
+                        self._mutable_helpers[con] = [mutable_constant]
+                elif con.has_ub():
+                    rhs_expr = con.upper - repn_constant
+                    rhs_val = value(rhs_expr)
+                    gurobipy_con = self._solver_model.addLConstr(
+                        gurobi_expr, gurobipy.GRB.LESS_EQUAL, rhs_val, name=conname
+                    )
+                    if not is_constant(rhs_expr):
+                        mutable_constant = _MutableConstant()
+                        mutable_constant.expr = rhs_expr
+                        mutable_constant.con = gurobipy_con
+                        self._mutable_helpers[con] = [mutable_constant]
+                else:
+                    raise ValueError(
+                        "Constraint does not have a lower "
+                        "or an upper bound: {0} \n".format(con)
+                    )
+                for tmp in mutable_linear_coefficients:
+                    tmp.con = gurobipy_con
+                    tmp.gurobi_model = self._solver_model
+                if len(mutable_linear_coefficients) > 0:
+                    if con not in self._mutable_helpers:
+                        self._mutable_helpers[con] = mutable_linear_coefficients
+                    else:
+                        self._mutable_helpers[con].extend(mutable_linear_coefficients)
+            elif gurobi_expr.__class__ is gurobipy.QuadExpr:
+                if con.equality:
+                    rhs_expr = con.lower - repn_constant
+                    rhs_val = value(rhs_expr)
+                    gurobipy_con = self._solver_model.addQConstr(
+                        gurobi_expr, gurobipy.GRB.EQUAL, rhs_val, name=conname
+                    )
+                elif con.has_lb() and con.has_ub():
+                    raise NotImplementedError(
+                        'Quadratic range constraints are not supported'
+                    )
+                elif con.has_lb():
+                    rhs_expr = con.lower - repn_constant
+                    rhs_val = value(rhs_expr)
+                    gurobipy_con = self._solver_model.addQConstr(
+                        gurobi_expr, gurobipy.GRB.GREATER_EQUAL, rhs_val, name=conname
+                    )
+                elif con.has_ub():
+                    rhs_expr = con.upper - repn_constant
+                    rhs_val = value(rhs_expr)
+                    gurobipy_con = self._solver_model.addQConstr(
+                        gurobi_expr, gurobipy.GRB.LESS_EQUAL, rhs_val, name=conname
+                    )
+                else:
+                    raise ValueError(
+                        "Constraint does not have a lower "
+                        "or an upper bound: {0} \n".format(con)
+                    )
+                if (
+                    len(mutable_linear_coefficients) > 0
+                    or len(mutable_quadratic_coefficients) > 0
+                    or not is_constant(repn_constant)
+                ):
+                    mutable_constant = _MutableConstant()
+                    mutable_constant.expr = rhs_expr
+                    mutable_quadratic_constraint = _MutableQuadraticConstraint(
+                        self._solver_model,
+                        gurobipy_con,
+                        mutable_constant,
+                        mutable_linear_coefficients,
+                        mutable_quadratic_coefficients,
+                    )
+                    self._mutable_quadratic_helpers[con] = mutable_quadratic_constraint
+            else:
+                raise ValueError(
+                    'Unrecognized Gurobi expression type: ' + str(gurobi_expr.__class__)
+                )
+
+            self._pyomo_con_to_solver_con_map[con] = gurobipy_con
+            self._solver_con_to_pyomo_con_map[id(gurobipy_con)] = con
+        self._constraints_added_since_update.update(cons)
+        self._needs_updated = True
+
+    def _add_sos_constraints(self, cons: List[SOSConstraintData]):
+        for con in cons:
+            conname = self._symbol_map.getSymbol(con, self._labeler)
+            level = con.level
+            if level == 1:
+                sos_type = gurobipy.GRB.SOS_TYPE1
+            elif level == 2:
+                sos_type = gurobipy.GRB.SOS_TYPE2
+            else:
+                raise ValueError(
+                    "Solver does not support SOS level {0} constraints".format(level)
+                )
+
+            gurobi_vars = []
+            weights = []
+
+            for v, w in con.get_items():
+                v_id = id(v)
+                gurobi_vars.append(self._pyomo_var_to_solver_var_map[v_id])
+                weights.append(w)
+
+            gurobipy_con = self._solver_model.addSOS(sos_type, gurobi_vars, weights)
+            self._pyomo_sos_to_solver_sos_map[con] = gurobipy_con
+        self._constraints_added_since_update.update(cons)
+        self._needs_updated = True
+
+    def _remove_constraints(self, cons: List[ConstraintData]):
+        for con in cons:
+            if con in self._constraints_added_since_update:
+                self._update_gurobi_model()
+            solver_con = self._pyomo_con_to_solver_con_map[con]
+            self._solver_model.remove(solver_con)
+            self._symbol_map.removeSymbol(con)
+            del self._pyomo_con_to_solver_con_map[con]
+            del self._solver_con_to_pyomo_con_map[id(solver_con)]
+            self._range_constraints.discard(con)
+            self._mutable_helpers.pop(con, None)
+            self._mutable_quadratic_helpers.pop(con, None)
+        self._needs_updated = True
+
+    def _remove_sos_constraints(self, cons: List[SOSConstraintData]):
+        for con in cons:
+            if con in self._constraints_added_since_update:
+                self._update_gurobi_model()
+            solver_sos_con = self._pyomo_sos_to_solver_sos_map[con]
+            self._solver_model.remove(solver_sos_con)
+            self._symbol_map.removeSymbol(con)
+            del self._pyomo_sos_to_solver_sos_map[con]
+        self._needs_updated = True
+
+    def _remove_variables(self, variables: List[VarData]):
+        for var in variables:
+            v_id = id(var)
+            if var in self._vars_added_since_update:
+                self._update_gurobi_model()
+            solver_var = self._pyomo_var_to_solver_var_map[v_id]
+            self._solver_model.remove(solver_var)
+            self._symbol_map.removeSymbol(var)
+            del self._pyomo_var_to_solver_var_map[v_id]
+            self._mutable_bounds.pop(v_id, None)
+        self._needs_updated = True
+
+    def _remove_parameters(self, params: List[ParamData]):
+        pass
+
+    def _update_variables(self, variables: List[VarData]):
+        for var in variables:
+            var_id = id(var)
+            if var_id not in self._pyomo_var_to_solver_var_map:
+                raise ValueError(
+                    'The Var provided to update_var needs to be added first: {0}'.format(
+                        var
+                    )
+                )
+            self._mutable_bounds.pop((var_id, 'lb'), None)
+            self._mutable_bounds.pop((var_id, 'ub'), None)
+            gurobipy_var = self._pyomo_var_to_solver_var_map[var_id]
+            lb, ub, vtype = self._process_domain_and_bounds(
+                var, var_id, None, None, None, gurobipy_var
+            )
+            gurobipy_var.setAttr('lb', lb)
+            gurobipy_var.setAttr('ub', ub)
+            gurobipy_var.setAttr('vtype', vtype)
+        self._needs_updated = True
+
+    def update_parameters(self):
+        for con, helpers in self._mutable_helpers.items():
+            for helper in helpers:
+                helper.update()
+        for k, (v, helper) in self._mutable_bounds.items():
+            helper.update()
+
+        for con, helper in self._mutable_quadratic_helpers.items():
+            if con in self._constraints_added_since_update:
+                self._update_gurobi_model()
+            gurobi_con = helper.con
+            new_gurobi_expr = helper.get_updated_expression()
+            new_rhs = helper.get_updated_rhs()
+            new_sense = gurobi_con.qcsense
+            pyomo_con = self._solver_con_to_pyomo_con_map[id(gurobi_con)]
+            name = self._symbol_map.getSymbol(pyomo_con, self._labeler)
+            self._solver_model.remove(gurobi_con)
+            new_con = self._solver_model.addQConstr(
+                new_gurobi_expr, new_sense, new_rhs, name=name
+            )
+            self._pyomo_con_to_solver_con_map[id(pyomo_con)] = new_con
+            del self._solver_con_to_pyomo_con_map[id(gurobi_con)]
+            self._solver_con_to_pyomo_con_map[id(new_con)] = pyomo_con
+            helper.con = new_con
+            self._constraints_added_since_update.add(con)
+
+        helper = self._mutable_objective
+        pyomo_obj = self._objective
+        new_gurobi_expr = helper.get_updated_expression()
+        if new_gurobi_expr is not None:
+            if pyomo_obj.sense == minimize:
+                sense = gurobipy.GRB.MINIMIZE
+            else:
+                sense = gurobipy.GRB.MAXIMIZE
+            self._solver_model.setObjective(new_gurobi_expr, sense=sense)
+
+    def _set_objective(self, obj):
+        if obj is None:
+            sense = gurobipy.GRB.MINIMIZE
+            gurobi_expr = 0
+            repn_constant = 0
+            mutable_linear_coefficients = list()
+            mutable_quadratic_coefficients = list()
+        else:
+            if obj.sense == minimize:
+                sense = gurobipy.GRB.MINIMIZE
+            elif obj.sense == maximize:
+                sense = gurobipy.GRB.MAXIMIZE
+            else:
+                raise ValueError(
+                    'Objective sense is not recognized: {0}'.format(obj.sense)
+                )
+
+            (
+                gurobi_expr,
+                repn_constant,
+                mutable_linear_coefficients,
+                mutable_quadratic_coefficients,
+            ) = self._get_expr_from_pyomo_expr(obj.expr)
+
+        mutable_constant = _MutableConstant()
+        mutable_constant.expr = repn_constant
+        mutable_objective = _MutableObjective(
+            self._solver_model,
+            mutable_constant,
+            mutable_linear_coefficients,
+            mutable_quadratic_coefficients,
+        )
+        self._mutable_objective = mutable_objective
+
+        # These two lines are needed as a workaround
+        # see PR #2454
+        self._solver_model.setObjective(0)
+        self._solver_model.update()
+
+        self._solver_model.setObjective(gurobi_expr + value(repn_constant), sense=sense)
+        self._needs_updated = True
+
+    def _postsolve(self, timer: HierarchicalTimer):
+        config = self._config
+
+        gprob = self._solver_model
+        grb = gurobipy.GRB
+        status = gprob.Status
+
+        results = Results()
+        results.solution_loader = GurobiSolutionLoader(self)
+        results.timing_info.gurobi_time = gprob.Runtime
+
+        if gprob.SolCount > 0:
+            if status == grb.OPTIMAL:
+                results.solution_status = SolutionStatus.optimal
+            else:
+                results.solution_status = SolutionStatus.feasible
+        else:
+            results.solution_status = SolutionStatus.noSolution
+
+        if status == grb.LOADED:  # problem is loaded, but no solution
+            results.termination_condition = TerminationCondition.unknown
+        elif status == grb.OPTIMAL:  # optimal
+            results.termination_condition = (
+                TerminationCondition.convergenceCriteriaSatisfied
+            )
+        elif status == grb.INFEASIBLE:
+            results.termination_condition = TerminationCondition.provenInfeasible
+        elif status == grb.INF_OR_UNBD:
+            results.termination_condition = TerminationCondition.infeasibleOrUnbounded
+        elif status == grb.UNBOUNDED:
+            results.termination_condition = TerminationCondition.unbounded
+        elif status == grb.CUTOFF:
+            results.termination_condition = TerminationCondition.objectiveLimit
+        elif status == grb.ITERATION_LIMIT:
+            results.termination_condition = TerminationCondition.iterationLimit
+        elif status == grb.NODE_LIMIT:
+            results.termination_condition = TerminationCondition.iterationLimit
+        elif status == grb.TIME_LIMIT:
+            results.termination_condition = TerminationCondition.maxTimeLimit
+        elif status == grb.SOLUTION_LIMIT:
+            results.termination_condition = TerminationCondition.unknown
+        elif status == grb.INTERRUPTED:
+            results.termination_condition = TerminationCondition.interrupted
+        elif status == grb.NUMERIC:
+            results.termination_condition = TerminationCondition.unknown
+        elif status == grb.SUBOPTIMAL:
+            results.termination_condition = TerminationCondition.unknown
+        elif status == grb.USER_OBJ_LIMIT:
+            results.termination_condition = TerminationCondition.objectiveLimit
+        else:
+            results.termination_condition = TerminationCondition.unknown
+
+        if (
+            results.termination_condition
+            != TerminationCondition.convergenceCriteriaSatisfied
+            and config.raise_exception_on_nonoptimal_result
+        ):
+            raise RuntimeError(
+                'Solver did not find the optimal solution. Set opt.config.raise_exception_on_nonoptimal_result = False to bypass this error.'
+            )
+
+        results.incumbent_objective = None
+        results.objective_bound = None
+        if self._objective is not None:
+            try:
+                results.incumbent_objective = gprob.ObjVal
+            except (gurobipy.GurobiError, AttributeError):
+                results.incumbent_objective = None
+            try:
+                results.objective_bound = gprob.ObjBound
+            except (gurobipy.GurobiError, AttributeError):
+                if self._objective.sense == minimize:
+                    results.objective_bound = -math.inf
+                else:
+                    results.objective_bound = math.inf
+
+            if results.incumbent_objective is not None and not math.isfinite(
+                results.incumbent_objective
+            ):
+                results.incumbent_objective = None
+
+        results.iteration_count = gprob.getAttr('IterCount')
+
+        timer.start('load solution')
+        if config.load_solutions:
+            if gprob.SolCount > 0:
+                self._load_vars()
+            else:
+                raise RuntimeError(
+                    'A feasible solution was not found, so no solution can be loaded.'
+                    'Please set opt.config.load_solutions=False and check '
+                    'results.solution_status and '
+                    'results.incumbent_objective before loading a solution.'
+                )
+        timer.stop('load solution')
+
+        return results
+
+    def _load_suboptimal_mip_solution(self, vars_to_load, solution_number):
+        if (
+            self.get_model_attr('NumIntVars') == 0
+            and self.get_model_attr('NumBinVars') == 0
+        ):
+            raise ValueError(
+                'Cannot obtain suboptimal solutions for a continuous model'
+            )
+        var_map = self._pyomo_var_to_solver_var_map
+        ref_vars = self._referenced_variables
+        original_solution_number = self.get_gurobi_param_info('SolutionNumber')[2]
+        self.set_gurobi_param('SolutionNumber', solution_number)
+        gurobi_vars_to_load = [var_map[pyomo_var] for pyomo_var in vars_to_load]
+        vals = self._solver_model.getAttr("Xn", gurobi_vars_to_load)
+        res = ComponentMap()
+        for var_id, val in zip(vars_to_load, vals):
+            using_cons, using_sos, using_obj = ref_vars[var_id]
+            if using_cons or using_sos or (using_obj is not None):
+                res[self._vars[var_id][0]] = val
+        self.set_gurobi_param('SolutionNumber', original_solution_number)
+        return res
+
+    def _load_vars(self, vars_to_load=None, solution_number=0):
+        for v, val in self._get_primals(
+            vars_to_load=vars_to_load, solution_number=solution_number
+        ).items():
+            v.set_value(val, skip_validation=True)
+        StaleFlagManager.mark_all_as_stale(delayed=True)
+
+    def _get_primals(self, vars_to_load=None, solution_number=0):
+        if self._needs_updated:
+            self._update_gurobi_model()  # this is needed to ensure that solutions cannot be loaded after the model has been changed
+
+        if self._solver_model.SolCount == 0:
+            raise RuntimeError(
+                'Solver does not currently have a valid solution. Please '
+                'check the termination condition.'
+            )
+
+        var_map = self._pyomo_var_to_solver_var_map
+        ref_vars = self._referenced_variables
+        if vars_to_load is None:
+            vars_to_load = self._pyomo_var_to_solver_var_map.keys()
+        else:
+            vars_to_load = [id(v) for v in vars_to_load]
+
+        if solution_number != 0:
+            return self._load_suboptimal_mip_solution(
+                vars_to_load=vars_to_load, solution_number=solution_number
+            )
+        else:
+            gurobi_vars_to_load = [
+                var_map[pyomo_var_id] for pyomo_var_id in vars_to_load
+            ]
+            vals = self._solver_model.getAttr("X", gurobi_vars_to_load)
+
+            res = ComponentMap()
+            for var_id, val in zip(vars_to_load, vals):
+                using_cons, using_sos, using_obj = ref_vars[var_id]
+                if using_cons or using_sos or (using_obj is not None):
+                    res[self._vars[var_id][0]] = val
+            return res
+
+    def _get_reduced_costs(self, vars_to_load=None):
+        if self._needs_updated:
+            self._update_gurobi_model()
+
+        if self._solver_model.Status != gurobipy.GRB.OPTIMAL:
+            raise RuntimeError(
+                'Solver does not currently have valid reduced costs. Please '
+                'check the termination condition.'
+            )
+
+        var_map = self._pyomo_var_to_solver_var_map
+        ref_vars = self._referenced_variables
+        res = ComponentMap()
+        if vars_to_load is None:
+            vars_to_load = self._pyomo_var_to_solver_var_map.keys()
+        else:
+            vars_to_load = [id(v) for v in vars_to_load]
+
+        gurobi_vars_to_load = [var_map[pyomo_var_id] for pyomo_var_id in vars_to_load]
+        vals = self._solver_model.getAttr("Rc", gurobi_vars_to_load)
+
+        for var_id, val in zip(vars_to_load, vals):
+            using_cons, using_sos, using_obj = ref_vars[var_id]
+            if using_cons or using_sos or (using_obj is not None):
+                res[self._vars[var_id][0]] = val
+
+        return res
+
+    def _get_duals(self, cons_to_load=None):
+        if self._needs_updated:
+            self._update_gurobi_model()
+
+        if self._solver_model.Status != gurobipy.GRB.OPTIMAL:
+            raise RuntimeError(
+                'Solver does not currently have valid duals. Please '
+                'check the termination condition.'
+            )
+
+        con_map = self._pyomo_con_to_solver_con_map
+        reverse_con_map = self._solver_con_to_pyomo_con_map
+        dual = dict()
+
+        if cons_to_load is None:
+            linear_cons_to_load = self._solver_model.getConstrs()
+            quadratic_cons_to_load = self._solver_model.getQConstrs()
+        else:
+            gurobi_cons_to_load = OrderedSet(
+                [con_map[pyomo_con] for pyomo_con in cons_to_load]
+            )
+            linear_cons_to_load = list(
+                gurobi_cons_to_load.intersection(
+                    OrderedSet(self._solver_model.getConstrs())
+                )
+            )
+            quadratic_cons_to_load = list(
+                gurobi_cons_to_load.intersection(
+                    OrderedSet(self._solver_model.getQConstrs())
+                )
+            )
+        linear_vals = self._solver_model.getAttr("Pi", linear_cons_to_load)
+        quadratic_vals = self._solver_model.getAttr("QCPi", quadratic_cons_to_load)
+
+        for gurobi_con, val in zip(linear_cons_to_load, linear_vals):
+            pyomo_con = reverse_con_map[id(gurobi_con)]
+            dual[pyomo_con] = val
+        for gurobi_con, val in zip(quadratic_cons_to_load, quadratic_vals):
+            pyomo_con = reverse_con_map[id(gurobi_con)]
+            dual[pyomo_con] = val
+
+        return dual
+
+    def update(self, timer: HierarchicalTimer = None):
+        if self._needs_updated:
+            self._update_gurobi_model()
+        super(Gurobi, self).update(timer=timer)
+        self._update_gurobi_model()
+
+    def _update_gurobi_model(self):
+        self._solver_model.update()
+        self._constraints_added_since_update = OrderedSet()
+        self._vars_added_since_update = ComponentSet()
+        self._needs_updated = False
+
+    def get_model_attr(self, attr):
+        """
+        Get the value of an attribute on the Gurobi model.
+
+        Parameters
+        ----------
+        attr: str
+            The attribute to get. See Gurobi documentation for descriptions of the attributes.
+        """
+        if self._needs_updated:
+            self._update_gurobi_model()
+        return self._solver_model.getAttr(attr)
+
+    def write(self, filename):
+        """
+        Write the model to a file (e.g., and lp file).
+
+        Parameters
+        ----------
+        filename: str
+            Name of the file to which the model should be written.
+        """
+        self._solver_model.write(filename)
+        self._constraints_added_since_update = OrderedSet()
+        self._vars_added_since_update = ComponentSet()
+        self._needs_updated = False
+
+    def set_linear_constraint_attr(self, con, attr, val):
+        """
+        Set the value of an attribute on a gurobi linear constraint.
+
+        Parameters
+        ----------
+        con: pyomo.core.base.constraint.ConstraintData
+            The pyomo constraint for which the corresponding gurobi constraint attribute
+            should be modified.
+        attr: str
+            The attribute to be modified. Options are:
+                CBasis
+                DStart
+                Lazy
+        val: any
+            See gurobi documentation for acceptable values.
+        """
+        if attr in {'Sense', 'RHS', 'ConstrName'}:
+            raise ValueError(
+                'Linear constraint attr {0} cannot be set with'.format(attr)
+                + ' the set_linear_constraint_attr method. Please use'
+                + ' the remove_constraint and add_constraint methods.'
+            )
+        self._pyomo_con_to_solver_con_map[con].setAttr(attr, val)
+        self._needs_updated = True
+
+    def set_var_attr(self, var, attr, val):
+        """
+        Set the value of an attribute on a gurobi variable.
+
+        Parameters
+        ----------
+        var: pyomo.core.base.var.VarData
+            The pyomo var for which the corresponding gurobi var attribute
+            should be modified.
+        attr: str
+            The attribute to be modified. Options are:
+                Start
+                VarHintVal
+                VarHintPri
+                BranchPriority
+                VBasis
+                PStart
+        val: any
+            See gurobi documentation for acceptable values.
+        """
+        if attr in {'LB', 'UB', 'VType', 'VarName'}:
+            raise ValueError(
+                'Var attr {0} cannot be set with'.format(attr)
+                + ' the set_var_attr method. Please use'
+                + ' the update_var method.'
+            )
+        if attr == 'Obj':
+            raise ValueError(
+                'Var attr Obj cannot be set with'
+                + ' the set_var_attr method. Please use'
+                + ' the set_objective method.'
+            )
+        self._pyomo_var_to_solver_var_map[id(var)].setAttr(attr, val)
+        self._needs_updated = True
+
+    def get_var_attr(self, var, attr):
+        """
+        Get the value of an attribute on a gurobi var.
+
+        Parameters
+        ----------
+        var: pyomo.core.base.var.VarData
+            The pyomo var for which the corresponding gurobi var attribute
+            should be retrieved.
+        attr: str
+            The attribute to get. See gurobi documentation
+        """
+        if self._needs_updated:
+            self._update_gurobi_model()
+        return self._pyomo_var_to_solver_var_map[id(var)].getAttr(attr)
+
+    def get_linear_constraint_attr(self, con, attr):
+        """
+        Get the value of an attribute on a gurobi linear constraint.
+
+        Parameters
+        ----------
+        con: pyomo.core.base.constraint.ConstraintData
+            The pyomo constraint for which the corresponding gurobi constraint attribute
+            should be retrieved.
+        attr: str
+            The attribute to get. See the Gurobi documentation
+        """
+        if self._needs_updated:
+            self._update_gurobi_model()
+        return self._pyomo_con_to_solver_con_map[con].getAttr(attr)
+
+    def get_sos_attr(self, con, attr):
+        """
+        Get the value of an attribute on a gurobi sos constraint.
+
+        Parameters
+        ----------
+        con: pyomo.core.base.sos.SOSConstraintData
+            The pyomo SOS constraint for which the corresponding gurobi SOS constraint attribute
+            should be retrieved.
+        attr: str
+            The attribute to get. See the Gurobi documentation
+        """
+        if self._needs_updated:
+            self._update_gurobi_model()
+        return self._pyomo_sos_to_solver_sos_map[con].getAttr(attr)
+
+    def get_quadratic_constraint_attr(self, con, attr):
+        """
+        Get the value of an attribute on a gurobi quadratic constraint.
+
+        Parameters
+        ----------
+        con: pyomo.core.base.constraint.ConstraintData
+            The pyomo constraint for which the corresponding gurobi constraint attribute
+            should be retrieved.
+        attr: str
+            The attribute to get. See the Gurobi documentation
+        """
+        if self._needs_updated:
+            self._update_gurobi_model()
+        return self._pyomo_con_to_solver_con_map[con].getAttr(attr)
+
+    def set_gurobi_param(self, param, val):
+        """
+        Set a gurobi parameter.
+
+        Parameters
+        ----------
+        param: str
+            The gurobi parameter to set. Options include any gurobi parameter.
+            Please see the Gurobi documentation for options.
+        val: any
+            The value to set the parameter to. See Gurobi documentation for possible values.
+        """
+        self._solver_model.setParam(param, val)
+
+    def get_gurobi_param_info(self, param):
+        """
+        Get information about a gurobi parameter.
+
+        Parameters
+        ----------
+        param: str
+            The gurobi parameter to get info for. See Gurobi documentation for possible options.
+
+        Returns
+        -------
+        six-tuple containing the parameter name, type, value, minimum value, maximum value, and default value.
+        """
+        return self._solver_model.getParamInfo(param)
+
+    def _intermediate_callback(self):
+        def f(gurobi_model, where):
+            self._callback_func(self._model, self, where)
+
+        return f
+
+    def set_callback(self, func=None):
+        """
+        Specify a callback for gurobi to use.
+
+        Parameters
+        ----------
+        func: function
+            The function to call. The function should have three arguments. The first will be the pyomo model being
+            solved. The second will be the GurobiPersistent instance. The third will be an enum member of
+            gurobipy.GRB.Callback. This will indicate where in the branch and bound algorithm gurobi is at. For
+            example, suppose we want to solve
+
+            .. math::
+
+                min 2*x + y
+
+                s.t.
+
+                    y >= (x-2)**2
+
+                    0 <= x <= 4
+
+                    y >= 0
+
+                    y integer
+
+            as an MILP using extended cutting planes in callbacks.
+
+                >>> from gurobipy import GRB # doctest:+SKIP
+                >>> import pyomo.environ as pe
+                >>> from pyomo.core.expr.taylor_series import taylor_series_expansion
+                >>> from pyomo.contrib import appsi
+                >>>
+                >>> m = pe.ConcreteModel()
+                >>> m.x = pe.Var(bounds=(0, 4))
+                >>> m.y = pe.Var(within=pe.Integers, bounds=(0, None))
+                >>> m.obj = pe.Objective(expr=2*m.x + m.y)
+                >>> m.cons = pe.ConstraintList()  # for the cutting planes
+                >>>
+                >>> def _add_cut(xval):
+                ...     # a function to generate the cut
+                ...     m.x.value = xval
+                ...     return m.cons.add(m.y >= taylor_series_expansion((m.x - 2)**2))
+                ...
+                >>> _c = _add_cut(0)  # start with 2 cuts at the bounds of x
+                >>> _c = _add_cut(4)  # this is an arbitrary choice
+                >>>
+                >>> opt = appsi.solvers.Gurobi()
+                >>> opt.config.stream_solver = True
+                >>> opt.set_instance(m) # doctest:+SKIP
+                >>> opt.gurobi_options['PreCrush'] = 1
+                >>> opt.gurobi_options['LazyConstraints'] = 1
+                >>>
+                >>> def my_callback(cb_m, cb_opt, cb_where):
+                ...     if cb_where == GRB.Callback.MIPSOL:
+                ...         cb_opt.cbGetSolution(vars=[m.x, m.y])
+                ...         if m.y.value < (m.x.value - 2)**2 - 1e-6:
+                ...             cb_opt.cbLazy(_add_cut(m.x.value))
+                ...
+                >>> opt.set_callback(my_callback)
+                >>> res = opt.solve(m) # doctest:+SKIP
+
+        """
+        if func is not None:
+            self._callback_func = func
+            self._callback = self._intermediate_callback()
+        else:
+            self._callback = None
+            self._callback_func = None
+
+    def cbCut(self, con):
+        """
+        Add a cut within a callback.
+
+        Parameters
+        ----------
+        con: pyomo.core.base.constraint.ConstraintData
+            The cut to add
+        """
+        if not con.active:
+            raise ValueError('cbCut expected an active constraint.')
+
+        if is_fixed(con.body):
+            raise ValueError('cbCut expected a non-trivial constraint')
+
+        (
+            gurobi_expr,
+            repn_constant,
+            mutable_linear_coefficients,
+            mutable_quadratic_coefficients,
+        ) = self._get_expr_from_pyomo_expr(con.body)
+
+        if con.has_lb():
+            if con.has_ub():
+                raise ValueError('Range constraints are not supported in cbCut.')
+            if not is_fixed(con.lower):
+                raise ValueError(
+                    'Lower bound of constraint {0} is not constant.'.format(con)
+                )
+        if con.has_ub():
+            if not is_fixed(con.upper):
+                raise ValueError(
+                    'Upper bound of constraint {0} is not constant.'.format(con)
+                )
+
+        if con.equality:
+            self._solver_model.cbCut(
+                lhs=gurobi_expr,
+                sense=gurobipy.GRB.EQUAL,
+                rhs=value(con.lower - repn_constant),
+            )
+        elif con.has_lb() and (value(con.lower) > -float('inf')):
+            self._solver_model.cbCut(
+                lhs=gurobi_expr,
+                sense=gurobipy.GRB.GREATER_EQUAL,
+                rhs=value(con.lower - repn_constant),
+            )
+        elif con.has_ub() and (value(con.upper) < float('inf')):
+            self._solver_model.cbCut(
+                lhs=gurobi_expr,
+                sense=gurobipy.GRB.LESS_EQUAL,
+                rhs=value(con.upper - repn_constant),
+            )
+        else:
+            raise ValueError(
+                'Constraint does not have a lower or an upper bound {0} \n'.format(con)
+            )
+
+    def cbGet(self, what):
+        return self._solver_model.cbGet(what)
+
+    def cbGetNodeRel(self, vars):
+        """
+        Parameters
+        ----------
+        vars: Var or iterable of Var
+        """
+        if not isinstance(vars, Iterable):
+            vars = [vars]
+        gurobi_vars = [self._pyomo_var_to_solver_var_map[id(i)] for i in vars]
+        var_values = self._solver_model.cbGetNodeRel(gurobi_vars)
+        for i, v in enumerate(vars):
+            v.set_value(var_values[i], skip_validation=True)
+
+    def cbGetSolution(self, vars):
+        """
+        Parameters
+        ----------
+        vars: iterable of vars
+        """
+        if not isinstance(vars, Iterable):
+            vars = [vars]
+        gurobi_vars = [self._pyomo_var_to_solver_var_map[id(i)] for i in vars]
+        var_values = self._solver_model.cbGetSolution(gurobi_vars)
+        for i, v in enumerate(vars):
+            v.set_value(var_values[i], skip_validation=True)
+
+    def cbLazy(self, con):
+        """
+        Parameters
+        ----------
+        con: pyomo.core.base.constraint.ConstraintData
+            The lazy constraint to add
+        """
+        if not con.active:
+            raise ValueError('cbLazy expected an active constraint.')
+
+        if is_fixed(con.body):
+            raise ValueError('cbLazy expected a non-trivial constraint')
+
+        (
+            gurobi_expr,
+            repn_constant,
+            mutable_linear_coefficients,
+            mutable_quadratic_coefficients,
+        ) = self._get_expr_from_pyomo_expr(con.body)
+
+        if con.has_lb():
+            if con.has_ub():
+                raise ValueError('Range constraints are not supported in cbLazy.')
+            if not is_fixed(con.lower):
+                raise ValueError(
+                    'Lower bound of constraint {0} is not constant.'.format(con)
+                )
+        if con.has_ub():
+            if not is_fixed(con.upper):
+                raise ValueError(
+                    'Upper bound of constraint {0} is not constant.'.format(con)
+                )
+
+        if con.equality:
+            self._solver_model.cbLazy(
+                lhs=gurobi_expr,
+                sense=gurobipy.GRB.EQUAL,
+                rhs=value(con.lower - repn_constant),
+            )
+        elif con.has_lb() and (value(con.lower) > -float('inf')):
+            self._solver_model.cbLazy(
+                lhs=gurobi_expr,
+                sense=gurobipy.GRB.GREATER_EQUAL,
+                rhs=value(con.lower - repn_constant),
+            )
+        elif con.has_ub() and (value(con.upper) < float('inf')):
+            self._solver_model.cbLazy(
+                lhs=gurobi_expr,
+                sense=gurobipy.GRB.LESS_EQUAL,
+                rhs=value(con.upper - repn_constant),
+            )
+        else:
+            raise ValueError(
+                'Constraint does not have a lower or an upper bound {0} \n'.format(con)
+            )
+
+    def cbSetSolution(self, vars, solution):
+        if not isinstance(vars, Iterable):
+            vars = [vars]
+        gurobi_vars = [self._pyomo_var_to_solver_var_map[id(i)] for i in vars]
+        self._solver_model.cbSetSolution(gurobi_vars, solution)
+
+    def cbUseSolution(self):
+        return self._solver_model.cbUseSolution()
+
+    def reset(self):
+        self._solver_model.reset()
diff --git a/pyomo/contrib/solver/gurobi_direct.py b/pyomo/contrib/solver/gurobi_direct.py
new file mode 100644
index 00000000000..edca7018f92
--- /dev/null
+++ b/pyomo/contrib/solver/gurobi_direct.py
@@ -0,0 +1,420 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import datetime
+import io
+import math
+import os
+
+from pyomo.common.config import ConfigValue
+from pyomo.common.collections import ComponentMap, ComponentSet
+from pyomo.common.dependencies import attempt_import
+from pyomo.common.enums import ObjectiveSense
+from pyomo.common.shutdown import python_is_shutting_down
+from pyomo.common.tee import capture_output, TeeStream
+from pyomo.common.timing import HierarchicalTimer
+
+from pyomo.contrib.solver.base import SolverBase
+from pyomo.contrib.solver.config import BranchAndBoundConfig
+from pyomo.contrib.solver.results import Results, SolutionStatus, TerminationCondition
+from pyomo.contrib.solver.solution import SolutionLoaderBase
+
+from pyomo.core.staleflag import StaleFlagManager
+
+from pyomo.repn.plugins.standard_form import LinearStandardFormCompiler
+
+gurobipy, gurobipy_available = attempt_import('gurobipy')
+
+
+class GurobiConfig(BranchAndBoundConfig):
+    def __init__(
+        self,
+        description=None,
+        doc=None,
+        implicit=False,
+        implicit_domain=None,
+        visibility=0,
+    ):
+        super(GurobiConfig, self).__init__(
+            description=description,
+            doc=doc,
+            implicit=implicit,
+            implicit_domain=implicit_domain,
+            visibility=visibility,
+        )
+        self.use_mipstart: bool = self.declare(
+            'use_mipstart',
+            ConfigValue(
+                default=False,
+                domain=bool,
+                description="If True, the current values of the integer variables "
+                "will be passed to Gurobi.",
+            ),
+        )
+
+
+class GurobiDirectSolutionLoader(SolutionLoaderBase):
+    def __init__(self, grb_model, grb_cons, grb_vars, pyo_cons, pyo_vars, pyo_obj):
+        self._grb_model = grb_model
+        self._grb_cons = grb_cons
+        self._grb_vars = grb_vars
+        self._pyo_cons = pyo_cons
+        self._pyo_vars = pyo_vars
+        self._pyo_obj = pyo_obj
+        GurobiDirect._num_instances += 1
+
+    def __del__(self):
+        if not python_is_shutting_down():
+            GurobiDirect._num_instances -= 1
+            if GurobiDirect._num_instances == 0:
+                GurobiDirect.release_license()
+
+    def load_vars(self, vars_to_load=None, solution_number=0):
+        assert solution_number == 0
+        if self._grb_model.SolCount == 0:
+            raise RuntimeError(
+                'Solver does not currently have a valid solution. Please '
+                'check the termination condition.'
+            )
+
+        iterator = zip(self._pyo_vars, self._grb_vars.x.tolist())
+        if vars_to_load:
+            vars_to_load = ComponentSet(vars_to_load)
+            iterator = filter(lambda var_val: var_val[0] in vars_to_load, iterator)
+        for p_var, g_var in iterator:
+            p_var.set_value(g_var, skip_validation=True)
+        StaleFlagManager.mark_all_as_stale(delayed=True)
+
+    def get_primals(self, vars_to_load=None, solution_number=0):
+        assert solution_number == 0
+        if self._grb_model.SolCount == 0:
+            raise RuntimeError(
+                'Solver does not currently have a valid solution. Please '
+                'check the termination condition.'
+            )
+
+        iterator = zip(self._pyo_vars, self._grb_vars.x.tolist())
+        if vars_to_load:
+            vars_to_load = ComponentSet(vars_to_load)
+            iterator = filter(lambda var_val: var_val[0] in vars_to_load, iterator)
+        return ComponentMap(iterator)
+
+    def get_duals(self, cons_to_load=None):
+        if self._grb_model.Status != gurobipy.GRB.OPTIMAL:
+            raise RuntimeError(
+                'Solver does not currently have valid duals. Please '
+                'check the termination condition.'
+            )
+
+        def dedup(_iter):
+            last = None
+            for con_info_dual in _iter:
+                if not con_info_dual[1] and con_info_dual[0][0] is last:
+                    continue
+                last = con_info_dual[0][0]
+                yield con_info_dual
+
+        iterator = dedup(zip(self._pyo_cons, self._grb_cons.getAttr('Pi').tolist()))
+        if cons_to_load:
+            cons_to_load = set(cons_to_load)
+            iterator = filter(
+                lambda con_info_dual: con_info_dual[0][0] in cons_to_load, iterator
+            )
+        return {con_info[0]: dual for con_info, dual in iterator}
+
+    def get_reduced_costs(self, vars_to_load=None):
+        if self._grb_model.Status != gurobipy.GRB.OPTIMAL:
+            raise RuntimeError(
+                'Solver does not currently have valid reduced costs. Please '
+                'check the termination condition.'
+            )
+
+        iterator = zip(self._pyo_vars, self._grb_vars.getAttr('Rc').tolist())
+        if vars_to_load:
+            vars_to_load = ComponentSet(vars_to_load)
+            iterator = filter(lambda var_rc: var_rc[0] in vars_to_load, iterator)
+        return ComponentMap(iterator)
+
+
+class GurobiDirect(SolverBase):
+    CONFIG = GurobiConfig()
+
+    _available = None
+    _num_instances = 0
+    _tc_map = None
+
+    def __init__(self, **kwds):
+        super().__init__(**kwds)
+        GurobiDirect._num_instances += 1
+
+    def available(self):
+        if not gurobipy_available:  # this triggers the deferred import
+            return self.Availability.NotFound
+        elif self._available == self.Availability.BadVersion:
+            return self.Availability.BadVersion
+        else:
+            return self._check_license()
+
+    def _check_license(self):
+        avail = False
+        try:
+            # Gurobipy writes out license file information when creating
+            # the environment
+            with capture_output(capture_fd=True):
+                m = gurobipy.Model()
+            avail = True
+        except gurobipy.GurobiError:
+            avail = False
+
+        if avail:
+            if self._available is None:
+                self._available = GurobiDirect._check_full_license(m)
+            return self._available
+        else:
+            return self.Availability.BadLicense
+
+    @classmethod
+    def _check_full_license(cls, model=None):
+        if model is None:
+            model = gurobipy.Model()
+        model.setParam('OutputFlag', 0)
+        try:
+            model.addVars(range(2001))
+            model.optimize()
+            return cls.Availability.FullLicense
+        except gurobipy.GurobiError:
+            return cls.Availability.LimitedLicense
+
+    def __del__(self):
+        if not python_is_shutting_down():
+            GurobiDirect._num_instances -= 1
+            if GurobiDirect._num_instances == 0:
+                self.release_license()
+
+    @staticmethod
+    def release_license():
+        if gurobipy_available:
+            with capture_output(capture_fd=True):
+                gurobipy.disposeDefaultEnv()
+
+    def version(self):
+        version = (
+            gurobipy.GRB.VERSION_MAJOR,
+            gurobipy.GRB.VERSION_MINOR,
+            gurobipy.GRB.VERSION_TECHNICAL,
+        )
+        return version
+
+    def solve(self, model, **kwds) -> Results:
+        start_timestamp = datetime.datetime.now(datetime.timezone.utc)
+        config = self.config(value=kwds, preserve_implicit=True)
+        if config.timer is None:
+            config.timer = HierarchicalTimer()
+        timer = config.timer
+
+        StaleFlagManager.mark_all_as_stale()
+
+        timer.start('compile_model')
+        repn = LinearStandardFormCompiler().write(
+            model, mixed_form=True, set_sense=None
+        )
+        timer.stop('compile_model')
+
+        if len(repn.objectives) > 1:
+            raise ValueError(
+                f"The {self.__class__.__name__} solver only supports models "
+                f"with zero or one objectives (received {len(repn.objectives)})."
+            )
+
+        timer.start('prepare_matrices')
+        inf = float('inf')
+        ninf = -inf
+        lb = []
+        ub = []
+        for v in repn.columns:
+            _l, _u = v.bounds
+            if _l is None:
+                _l = ninf
+            if _u is None:
+                _u = inf
+            lb.append(_l)
+            ub.append(_u)
+        CON = gurobipy.GRB.CONTINUOUS
+        BIN = gurobipy.GRB.BINARY
+        INT = gurobipy.GRB.INTEGER
+        vtype = [
+            (
+                CON
+                if v.is_continuous()
+                else (BIN if v.is_binary() else INT if v.is_integer() else '?')
+            )
+            for v in repn.columns
+        ]
+        sense_type = '=<>'  # Note: ordering matches 0, 1, -1
+        sense = [sense_type[r[1]] for r in repn.rows]
+        timer.stop('prepare_matrices')
+
+        ostreams = [io.StringIO()] + config.tee
+
+        try:
+            orig_cwd = os.getcwd()
+            if config.working_dir:
+                os.chdir(config.working_dir)
+            with TeeStream(*ostreams) as t, capture_output(t.STDOUT, capture_fd=False):
+                gurobi_model = gurobipy.Model()
+
+                timer.start('transfer_model')
+                x = gurobi_model.addMVar(
+                    len(repn.columns),
+                    lb=lb,
+                    ub=ub,
+                    obj=repn.c.todense()[0] if repn.c.shape[0] else 0,
+                    vtype=vtype,
+                )
+                A = gurobi_model.addMConstr(repn.A, x, sense, repn.rhs)
+                if repn.c.shape[0]:
+                    gurobi_model.setAttr('ObjCon', repn.c_offset[0])
+                    gurobi_model.setAttr('ModelSense', int(repn.objectives[0].sense))
+                # Note: calling gurobi_model.update() here is not
+                # necessary (it will happen as part of optimize())
+                timer.stop('transfer_model')
+
+                options = config.solver_options
+
+                gurobi_model.setParam('LogToConsole', 1)
+
+                if config.threads is not None:
+                    gurobi_model.setParam('Threads', config.threads)
+                if config.time_limit is not None:
+                    gurobi_model.setParam('TimeLimit', config.time_limit)
+                if config.rel_gap is not None:
+                    gurobi_model.setParam('MIPGap', config.rel_gap)
+                if config.abs_gap is not None:
+                    gurobi_model.setParam('MIPGapAbs', config.abs_gap)
+
+                if config.use_mipstart:
+                    raise MouseTrap("MIPSTART not yet supported")
+
+                for key, option in options.items():
+                    gurobi_model.setParam(key, option)
+
+                timer.start('optimize')
+                gurobi_model.optimize()
+                timer.stop('optimize')
+        finally:
+            os.chdir(orig_cwd)
+
+        res = self._postsolve(
+            timer,
+            config,
+            GurobiDirectSolutionLoader(
+                gurobi_model, A, x, repn.rows, repn.columns, repn.objectives
+            ),
+        )
+        res.solver_configuration = config
+        res.solver_name = 'Gurobi'
+        res.solver_version = self.version()
+        res.solver_log = ostreams[0].getvalue()
+
+        end_timestamp = datetime.datetime.now(datetime.timezone.utc)
+        res.timing_info.start_timestamp = start_timestamp
+        res.timing_info.wall_time = (end_timestamp - start_timestamp).total_seconds()
+        res.timing_info.timer = timer
+        return res
+
+    def _postsolve(self, timer: HierarchicalTimer, config, loader):
+        grb_model = loader._grb_model
+        status = grb_model.Status
+
+        results = Results()
+        results.solution_loader = loader
+        results.timing_info.gurobi_time = grb_model.Runtime
+
+        if grb_model.SolCount > 0:
+            if status == gurobipy.GRB.OPTIMAL:
+                results.solution_status = SolutionStatus.optimal
+            else:
+                results.solution_status = SolutionStatus.feasible
+        else:
+            results.solution_status = SolutionStatus.noSolution
+
+        results.termination_condition = self._get_tc_map().get(
+            status, TerminationCondition.unknown
+        )
+
+        if (
+            results.termination_condition
+            != TerminationCondition.convergenceCriteriaSatisfied
+            and config.raise_exception_on_nonoptimal_result
+        ):
+            raise RuntimeError(
+                'Solver did not find the optimal solution. Set '
+                'opt.config.raise_exception_on_nonoptimal_result=False '
+                'to bypass this error.'
+            )
+
+        if loader._pyo_obj:
+            try:
+                if math.isfinite(grb_model.ObjVal):
+                    results.incumbent_objective = grb_model.ObjVal
+                else:
+                    results.incumbent_objective = None
+            except (gurobipy.GurobiError, AttributeError):
+                results.incumbent_objective = None
+            try:
+                results.objective_bound = grb_model.ObjBound
+            except (gurobipy.GurobiError, AttributeError):
+                if grb_model.ModelSense == ObjectiveSense.minimize:
+                    results.objective_bound = -math.inf
+                else:
+                    results.objective_bound = math.inf
+        else:
+            results.incumbent_objective = None
+            results.objective_bound = None
+
+        results.iteration_count = grb_model.getAttr('IterCount')
+
+        timer.start('load solution')
+        if config.load_solutions:
+            if grb_model.SolCount > 0:
+                results.solution_loader.load_vars()
+            else:
+                raise RuntimeError(
+                    'A feasible solution was not found, so no solution can be loaded.'
+                    'Please set opt.config.load_solutions=False and check '
+                    'results.solution_status and '
+                    'results.incumbent_objective before loading a solution.'
+                )
+        timer.stop('load solution')
+
+        return results
+
+    def _get_tc_map(self):
+        if GurobiDirect._tc_map is None:
+            grb = gurobipy.GRB
+            tc = TerminationCondition
+            GurobiDirect._tc_map = {
+                grb.LOADED: tc.unknown,  # problem is loaded, but no solution
+                grb.OPTIMAL: tc.convergenceCriteriaSatisfied,
+                grb.INFEASIBLE: tc.provenInfeasible,
+                grb.INF_OR_UNBD: tc.infeasibleOrUnbounded,
+                grb.UNBOUNDED: tc.unbounded,
+                grb.CUTOFF: tc.objectiveLimit,
+                grb.ITERATION_LIMIT: tc.iterationLimit,
+                grb.NODE_LIMIT: tc.iterationLimit,
+                grb.TIME_LIMIT: tc.maxTimeLimit,
+                grb.SOLUTION_LIMIT: tc.unknown,
+                grb.INTERRUPTED: tc.interrupted,
+                grb.NUMERIC: tc.unknown,
+                grb.SUBOPTIMAL: tc.unknown,
+                grb.USER_OBJ_LIMIT: tc.objectiveLimit,
+            }
+        return GurobiDirect._tc_map
diff --git a/pyomo/contrib/solver/ipopt.py b/pyomo/contrib/solver/ipopt.py
new file mode 100644
index 00000000000..c88696f531b
--- /dev/null
+++ b/pyomo/contrib/solver/ipopt.py
@@ -0,0 +1,537 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import logging
+import os
+import subprocess
+import datetime
+import io
+from typing import Mapping, Optional, Sequence
+
+from pyomo.common import Executable
+from pyomo.common.config import ConfigValue, document_kwargs_from_configdict, ConfigDict
+from pyomo.common.errors import (
+    PyomoException,
+    DeveloperError,
+    InfeasibleConstraintException,
+)
+from pyomo.common.tempfiles import TempfileManager
+from pyomo.common.timing import HierarchicalTimer
+from pyomo.core.base.var import VarData
+from pyomo.core.staleflag import StaleFlagManager
+from pyomo.repn.plugins.nl_writer import NLWriter, NLWriterInfo
+from pyomo.contrib.solver.base import SolverBase
+from pyomo.contrib.solver.config import SolverConfig
+from pyomo.contrib.solver.results import Results, TerminationCondition, SolutionStatus
+from pyomo.contrib.solver.sol_reader import parse_sol_file
+from pyomo.contrib.solver.solution import SolSolutionLoader
+from pyomo.common.tee import TeeStream
+from pyomo.core.expr.visitor import replace_expressions
+from pyomo.core.expr.numvalue import value
+from pyomo.core.base.suffix import Suffix
+from pyomo.common.collections import ComponentMap
+
+logger = logging.getLogger(__name__)
+
+
+class IpoptSolverError(PyomoException):
+    """
+    General exception to catch solver system errors
+    """
+
+
+class IpoptConfig(SolverConfig):
+    def __init__(
+        self,
+        description=None,
+        doc=None,
+        implicit=False,
+        implicit_domain=None,
+        visibility=0,
+    ):
+        super().__init__(
+            description=description,
+            doc=doc,
+            implicit=implicit,
+            implicit_domain=implicit_domain,
+            visibility=visibility,
+        )
+
+        self.executable: Executable = self.declare(
+            'executable',
+            ConfigValue(
+                default=Executable('ipopt'),
+                description="Preferred executable for ipopt. Defaults to searching the "
+                "``PATH`` for the first available ``ipopt``.",
+            ),
+        )
+        self.writer_config: ConfigDict = self.declare(
+            'writer_config', NLWriter.CONFIG()
+        )
+
+
+class IpoptSolutionLoader(SolSolutionLoader):
+    def get_reduced_costs(
+        self, vars_to_load: Optional[Sequence[VarData]] = None
+    ) -> Mapping[VarData, float]:
+        if self._nl_info is None:
+            raise RuntimeError(
+                'Solution loader does not currently have a valid solution. Please '
+                'check results.TerminationCondition and/or results.SolutionStatus.'
+            )
+        if len(self._nl_info.eliminated_vars) > 0:
+            raise NotImplementedError(
+                'For now, turn presolve off (opt.config.writer_config.linear_presolve=False) '
+                'to get dual variable values.'
+            )
+        if self._sol_data is None:
+            raise DeveloperError(
+                "Solution data is empty. This should not "
+                "have happened. Report this error to the Pyomo Developers."
+            )
+        if self._nl_info.scaling is None:
+            scale_list = [1] * len(self._nl_info.variables)
+            obj_scale = 1
+        else:
+            scale_list = self._nl_info.scaling.variables
+            obj_scale = self._nl_info.scaling.objectives[0]
+        sol_data = self._sol_data
+        nl_info = self._nl_info
+        zl_map = sol_data.var_suffixes['ipopt_zL_out']
+        zu_map = sol_data.var_suffixes['ipopt_zU_out']
+        rc = dict()
+        for ndx, v in enumerate(nl_info.variables):
+            scale = scale_list[ndx]
+            v_id = id(v)
+            rc[v_id] = (v, 0)
+            if ndx in zl_map:
+                zl = zl_map[ndx] * scale / obj_scale
+                if abs(zl) > abs(rc[v_id][1]):
+                    rc[v_id] = (v, zl)
+            if ndx in zu_map:
+                zu = zu_map[ndx] * scale / obj_scale
+                if abs(zu) > abs(rc[v_id][1]):
+                    rc[v_id] = (v, zu)
+
+        if vars_to_load is None:
+            res = ComponentMap(rc.values())
+            for v, _ in nl_info.eliminated_vars:
+                res[v] = 0
+        else:
+            res = ComponentMap()
+            for v in vars_to_load:
+                if id(v) in rc:
+                    res[v] = rc[id(v)][1]
+                else:
+                    # eliminated vars
+                    res[v] = 0
+        return res
+
+
+ipopt_command_line_options = {
+    'acceptable_compl_inf_tol',
+    'acceptable_constr_viol_tol',
+    'acceptable_dual_inf_tol',
+    'acceptable_tol',
+    'alpha_for_y',
+    'bound_frac',
+    'bound_mult_init_val',
+    'bound_push',
+    'bound_relax_factor',
+    'compl_inf_tol',
+    'constr_mult_init_max',
+    'constr_viol_tol',
+    'diverging_iterates_tol',
+    'dual_inf_tol',
+    'expect_infeasible_problem',
+    'file_print_level',
+    'halt_on_ampl_error',
+    'hessian_approximation',
+    'honor_original_bounds',
+    'linear_scaling_on_demand',
+    'linear_solver',
+    'linear_system_scaling',
+    'ma27_pivtol',
+    'ma27_pivtolmax',
+    'ma57_pivot_order',
+    'ma57_pivtol',
+    'ma57_pivtolmax',
+    'max_cpu_time',
+    'max_iter',
+    'max_refinement_steps',
+    'max_soc',
+    'maxit',
+    'min_refinement_steps',
+    'mu_init',
+    'mu_max',
+    'mu_oracle',
+    'mu_strategy',
+    'nlp_scaling_max_gradient',
+    'nlp_scaling_method',
+    'obj_scaling_factor',
+    'option_file_name',
+    'outlev',
+    'output_file',
+    'pardiso_matching_strategy',
+    'print_level',
+    'print_options_documentation',
+    'print_user_options',
+    'required_infeasibility_reduction',
+    'slack_bound_frac',
+    'slack_bound_push',
+    'tol',
+    'wantsol',
+    'warm_start_bound_push',
+    'warm_start_init_point',
+    'warm_start_mult_bound_push',
+    'watchdog_shortened_iter_trigger',
+}
+
+
+class Ipopt(SolverBase):
+    CONFIG = IpoptConfig()
+
+    def __init__(self, **kwds):
+        super().__init__(**kwds)
+        self._writer = NLWriter()
+        self._available_cache = None
+        self._version_cache = None
+        self._version_timeout = 2
+
+    def available(self, config=None):
+        if config is None:
+            config = self.config
+        pth = config.executable.path()
+        if self._available_cache is None or self._available_cache[0] != pth:
+            if pth is None:
+                self._available_cache = (None, self.Availability.NotFound)
+            else:
+                self._available_cache = (pth, self.Availability.FullLicense)
+        return self._available_cache[1]
+
+    def version(self, config=None):
+        if config is None:
+            config = self.config
+        pth = config.executable.path()
+        if self._version_cache is None or self._version_cache[0] != pth:
+            if pth is None:
+                self._version_cache = (None, None)
+            else:
+                results = subprocess.run(
+                    [str(pth), '--version'],
+                    timeout=self._version_timeout,
+                    stdout=subprocess.PIPE,
+                    stderr=subprocess.STDOUT,
+                    universal_newlines=True,
+                )
+                version = results.stdout.splitlines()[0]
+                version = version.split(' ')[1].strip()
+                version = tuple(int(i) for i in version.split('.'))
+                self._version_cache = (pth, version)
+        return self._version_cache[1]
+
+    def _write_options_file(self, filename: str, options: Mapping):
+        # First we need to determine if we even need to create a file.
+        # If options is empty, then we return False
+        opt_file_exists = False
+        if not options:
+            return False
+        # If it has options in it, parse them and write them to a file.
+        # If they are command line options, ignore them; they will be
+        # parsed during _create_command_line
+        for k, val in options.items():
+            if k not in ipopt_command_line_options:
+                opt_file_exists = True
+                with open(filename + '.opt', 'a+') as opt_file:
+                    opt_file.write(str(k) + ' ' + str(val) + '\n')
+        return opt_file_exists
+
+    def _create_command_line(self, basename: str, config: IpoptConfig, opt_file: bool):
+        cmd = [str(config.executable), basename + '.nl', '-AMPL']
+        if opt_file:
+            cmd.append('option_file_name=' + basename + '.opt')
+        if 'option_file_name' in config.solver_options:
+            raise ValueError(
+                'Pyomo generates the ipopt options file as part of the `solve` method. '
+                'Add all options to ipopt.config.solver_options instead.'
+            )
+        if (
+            config.time_limit is not None
+            and 'max_cpu_time' not in config.solver_options
+        ):
+            config.solver_options['max_cpu_time'] = config.time_limit
+        for k, val in config.solver_options.items():
+            if k in ipopt_command_line_options:
+                cmd.append(str(k) + '=' + str(val))
+        return cmd
+
+    @document_kwargs_from_configdict(CONFIG)
+    def solve(self, model, **kwds):
+        # Begin time tracking
+        start_timestamp = datetime.datetime.now(datetime.timezone.utc)
+        # Update configuration options, based on keywords passed to solve
+        config: IpoptConfig = self.config(value=kwds, preserve_implicit=True)
+        # Check if solver is available
+        avail = self.available(config)
+        if not avail:
+            raise IpoptSolverError(
+                f'Solver {self.__class__} is not available ({avail}).'
+            )
+        if config.threads:
+            logger.log(
+                logging.WARNING,
+                msg=f"The `threads` option was specified, but this is not used by {self.__class__}.",
+            )
+        if config.timer is None:
+            timer = HierarchicalTimer()
+        else:
+            timer = config.timer
+        StaleFlagManager.mark_all_as_stale()
+        with TempfileManager.new_context() as tempfile:
+            if config.working_dir is None:
+                dname = tempfile.mkdtemp()
+            else:
+                dname = config.working_dir
+            if not os.path.exists(dname):
+                os.mkdir(dname)
+            basename = os.path.join(dname, model.name)
+            if os.path.exists(basename + '.nl'):
+                raise RuntimeError(
+                    f"NL file with the same name {basename + '.nl'} already exists!"
+                )
+            # Note: the ASL has an issue where string constants written
+            # to the NL file (e.g. arguments in external functions) MUST
+            # be terminated with '\n' regardless of platform.  We will
+            # disable universal newlines in the NL file to prevent
+            # Python from mapping those '\n' to '\r\n' on Windows.
+            with open(basename + '.nl', 'w', newline='\n') as nl_file, open(
+                basename + '.row', 'w'
+            ) as row_file, open(basename + '.col', 'w') as col_file:
+                timer.start('write_nl_file')
+                self._writer.config.set_value(config.writer_config)
+                try:
+                    nl_info = self._writer.write(
+                        model,
+                        nl_file,
+                        row_file,
+                        col_file,
+                        symbolic_solver_labels=config.symbolic_solver_labels,
+                    )
+                    proven_infeasible = False
+                except InfeasibleConstraintException:
+                    proven_infeasible = True
+                timer.stop('write_nl_file')
+            if not proven_infeasible and len(nl_info.variables) > 0:
+                # Get a copy of the environment to pass to the subprocess
+                env = os.environ.copy()
+                if nl_info.external_function_libraries:
+                    if env.get('AMPLFUNC'):
+                        nl_info.external_function_libraries.append(env.get('AMPLFUNC'))
+                    env['AMPLFUNC'] = "\n".join(nl_info.external_function_libraries)
+                # Write the opt_file, if there should be one; return a bool to say
+                # whether or not we have one (so we can correctly build the command line)
+                opt_file = self._write_options_file(
+                    filename=basename, options=config.solver_options
+                )
+                # Call ipopt - passing the files via the subprocess
+                cmd = self._create_command_line(
+                    basename=basename, config=config, opt_file=opt_file
+                )
+                # this seems silly, but we have to give the subprocess slightly longer to finish than
+                # ipopt
+                if config.time_limit is not None:
+                    timeout = config.time_limit + min(
+                        max(1.0, 0.01 * config.time_limit), 100
+                    )
+                else:
+                    timeout = None
+
+                ostreams = [io.StringIO()] + config.tee
+                with TeeStream(*ostreams) as t:
+                    timer.start('subprocess')
+                    process = subprocess.run(
+                        cmd,
+                        timeout=timeout,
+                        env=env,
+                        universal_newlines=True,
+                        stdout=t.STDOUT,
+                        stderr=t.STDERR,
+                    )
+                    timer.stop('subprocess')
+                    # This is the stuff we need to parse to get the iterations
+                    # and time
+                    (iters, ipopt_time_nofunc, ipopt_time_func, ipopt_total_time) = (
+                        self._parse_ipopt_output(ostreams[0])
+                    )
+
+            if proven_infeasible:
+                results = Results()
+                results.termination_condition = TerminationCondition.provenInfeasible
+                results.solution_loader = SolSolutionLoader(None, None)
+                results.iteration_count = 0
+                results.timing_info.total_seconds = 0
+            elif len(nl_info.variables) == 0:
+                if len(nl_info.eliminated_vars) == 0:
+                    results = Results()
+                    results.termination_condition = TerminationCondition.emptyModel
+                    results.solution_loader = SolSolutionLoader(None, None)
+                else:
+                    results = Results()
+                    results.termination_condition = (
+                        TerminationCondition.convergenceCriteriaSatisfied
+                    )
+                    results.solution_status = SolutionStatus.optimal
+                    results.solution_loader = SolSolutionLoader(None, nl_info=nl_info)
+                    results.iteration_count = 0
+                    results.timing_info.total_seconds = 0
+            else:
+                if os.path.isfile(basename + '.sol'):
+                    with open(basename + '.sol', 'r') as sol_file:
+                        timer.start('parse_sol')
+                        results = self._parse_solution(sol_file, nl_info)
+                        timer.stop('parse_sol')
+                else:
+                    results = Results()
+                if process.returncode != 0:
+                    results.extra_info.return_code = process.returncode
+                    results.termination_condition = TerminationCondition.error
+                    results.solution_loader = SolSolutionLoader(None, None)
+                else:
+                    results.iteration_count = iters
+                    if ipopt_time_nofunc is not None:
+                        results.timing_info.ipopt_excluding_nlp_functions = (
+                            ipopt_time_nofunc
+                        )
+
+                    if ipopt_time_func is not None:
+                        results.timing_info.nlp_function_evaluations = ipopt_time_func
+                    if ipopt_total_time is not None:
+                        results.timing_info.total_seconds = ipopt_total_time
+        if (
+            config.raise_exception_on_nonoptimal_result
+            and results.solution_status != SolutionStatus.optimal
+        ):
+            raise RuntimeError(
+                'Solver did not find the optimal solution. Set '
+                'opt.config.raise_exception_on_nonoptimal_result = False to bypass this error.'
+            )
+
+        results.solver_name = self.name
+        results.solver_version = self.version(config)
+        if (
+            config.load_solutions
+            and results.solution_status == SolutionStatus.noSolution
+        ):
+            raise RuntimeError(
+                'A feasible solution was not found, so no solution can be loaded.'
+                'Please set opt.config.load_solutions=False to bypass this error.'
+            )
+
+        if config.load_solutions:
+            results.solution_loader.load_vars()
+            if (
+                hasattr(model, 'dual')
+                and isinstance(model.dual, Suffix)
+                and model.dual.import_enabled()
+            ):
+                model.dual.update(results.solution_loader.get_duals())
+            if (
+                hasattr(model, 'rc')
+                and isinstance(model.rc, Suffix)
+                and model.rc.import_enabled()
+            ):
+                model.rc.update(results.solution_loader.get_reduced_costs())
+
+        if (
+            results.solution_status in {SolutionStatus.feasible, SolutionStatus.optimal}
+            and len(nl_info.objectives) > 0
+        ):
+            if config.load_solutions:
+                results.incumbent_objective = value(nl_info.objectives[0])
+            else:
+                results.incumbent_objective = value(
+                    replace_expressions(
+                        nl_info.objectives[0].expr,
+                        substitution_map={
+                            id(v): val
+                            for v, val in results.solution_loader.get_primals().items()
+                        },
+                        descend_into_named_expressions=True,
+                        remove_named_expressions=True,
+                    )
+                )
+
+        results.solver_configuration = config
+        if not proven_infeasible and len(nl_info.variables) > 0:
+            results.solver_log = ostreams[0].getvalue()
+
+        # Capture/record end-time / wall-time
+        end_timestamp = datetime.datetime.now(datetime.timezone.utc)
+        results.timing_info.start_timestamp = start_timestamp
+        results.timing_info.wall_time = (
+            end_timestamp - start_timestamp
+        ).total_seconds()
+        results.timing_info.timer = timer
+        return results
+
+    def _parse_ipopt_output(self, stream: io.StringIO):
+        """
+        Parse an IPOPT output file and return:
+
+        * number of iterations
+        * time in IPOPT
+
+        """
+
+        iters = None
+        nofunc_time = None
+        func_time = None
+        total_time = None
+        # parse the output stream to get the iteration count and solver time
+        for line in stream.getvalue().splitlines():
+            if line.startswith("Number of Iterations....:"):
+                tokens = line.split()
+                iters = int(tokens[-1])
+            elif line.startswith(
+                "Total seconds in IPOPT                               ="
+            ):
+                # Newer versions of IPOPT no longer separate timing into
+                # two different values. This is so we have compatibility with
+                # both new and old versions
+                tokens = line.split()
+                total_time = float(tokens[-1])
+            elif line.startswith(
+                "Total CPU secs in IPOPT (w/o function evaluations)   ="
+            ):
+                tokens = line.split()
+                nofunc_time = float(tokens[-1])
+            elif line.startswith(
+                "Total CPU secs in NLP function evaluations           ="
+            ):
+                tokens = line.split()
+                func_time = float(tokens[-1])
+
+        return iters, nofunc_time, func_time, total_time
+
+    def _parse_solution(self, instream: io.TextIOBase, nl_info: NLWriterInfo):
+        results = Results()
+        res, sol_data = parse_sol_file(
+            sol_file=instream, nl_info=nl_info, result=results
+        )
+
+        if res.solution_status == SolutionStatus.noSolution:
+            res.solution_loader = SolSolutionLoader(None, None)
+        else:
+            res.solution_loader = IpoptSolutionLoader(
+                sol_data=sol_data, nl_info=nl_info
+            )
+
+        return res
diff --git a/pyomo/contrib/solver/persistent.py b/pyomo/contrib/solver/persistent.py
new file mode 100644
index 00000000000..71322b7043e
--- /dev/null
+++ b/pyomo/contrib/solver/persistent.py
@@ -0,0 +1,523 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  __________________________________________________________________________
+
+import abc
+from typing import List
+
+from pyomo.core.base.constraint import ConstraintData, Constraint
+from pyomo.core.base.sos import SOSConstraintData, SOSConstraint
+from pyomo.core.base.var import VarData
+from pyomo.core.base.param import ParamData, Param
+from pyomo.core.base.objective import ObjectiveData
+from pyomo.common.collections import ComponentMap
+from pyomo.common.timing import HierarchicalTimer
+from pyomo.core.expr.numvalue import NumericConstant
+from pyomo.contrib.solver.util import collect_vars_and_named_exprs, get_objective
+
+
+class PersistentSolverUtils(abc.ABC):
+    def __init__(self):
+        self._model = None
+        self._active_constraints = {}  # maps constraint to (lower, body, upper)
+        self._vars = {}  # maps var id to (var, lb, ub, fixed, domain, value)
+        self._params = {}  # maps param id to param
+        self._objective = None
+        self._objective_expr = None
+        self._objective_sense = None
+        self._named_expressions = (
+            {}
+        )  # maps constraint to list of tuples (named_expr, named_expr.expr)
+        self._external_functions = ComponentMap()
+        self._obj_named_expressions = []
+        self._referenced_variables = (
+            {}
+        )  # var_id: [dict[constraints, None], dict[sos constraints, None], None or objective]
+        self._vars_referenced_by_con = {}
+        self._vars_referenced_by_obj = []
+        self._expr_types = None
+
+    def set_instance(self, model):
+        saved_config = self.config
+        self.__init__()
+        self.config = saved_config
+        self._model = model
+        self.add_block(model)
+        if self._objective is None:
+            self.set_objective(None)
+
+    @abc.abstractmethod
+    def _add_variables(self, variables: List[VarData]):
+        pass
+
+    def add_variables(self, variables: List[VarData]):
+        for v in variables:
+            if id(v) in self._referenced_variables:
+                raise ValueError(
+                    'variable {name} has already been added'.format(name=v.name)
+                )
+            self._referenced_variables[id(v)] = [{}, {}, None]
+            self._vars[id(v)] = (
+                v,
+                v._lb,
+                v._ub,
+                v.fixed,
+                v.domain.get_interval(),
+                v.value,
+            )
+        self._add_variables(variables)
+
+    @abc.abstractmethod
+    def _add_parameters(self, params: List[ParamData]):
+        pass
+
+    def add_parameters(self, params: List[ParamData]):
+        for p in params:
+            self._params[id(p)] = p
+        self._add_parameters(params)
+
+    @abc.abstractmethod
+    def _add_constraints(self, cons: List[ConstraintData]):
+        pass
+
+    def _check_for_new_vars(self, variables: List[VarData]):
+        new_vars = {}
+        for v in variables:
+            v_id = id(v)
+            if v_id not in self._referenced_variables:
+                new_vars[v_id] = v
+        self.add_variables(list(new_vars.values()))
+
+    def _check_to_remove_vars(self, variables: List[VarData]):
+        vars_to_remove = {}
+        for v in variables:
+            v_id = id(v)
+            ref_cons, ref_sos, ref_obj = self._referenced_variables[v_id]
+            if len(ref_cons) == 0 and len(ref_sos) == 0 and ref_obj is None:
+                vars_to_remove[v_id] = v
+        self.remove_variables(list(vars_to_remove.values()))
+
+    def add_constraints(self, cons: List[ConstraintData]):
+        all_fixed_vars = {}
+        for con in cons:
+            if con in self._named_expressions:
+                raise ValueError(
+                    'constraint {name} has already been added'.format(name=con.name)
+                )
+            self._active_constraints[con] = (con.lower, con.body, con.upper)
+            tmp = collect_vars_and_named_exprs(con.body)
+            named_exprs, variables, fixed_vars, external_functions = tmp
+            self._check_for_new_vars(variables)
+            self._named_expressions[con] = [(e, e.expr) for e in named_exprs]
+            if len(external_functions) > 0:
+                self._external_functions[con] = external_functions
+            self._vars_referenced_by_con[con] = variables
+            for v in variables:
+                self._referenced_variables[id(v)][0][con] = None
+            if not self.config.auto_updates.treat_fixed_vars_as_params:
+                for v in fixed_vars:
+                    v.unfix()
+                    all_fixed_vars[id(v)] = v
+        self._add_constraints(cons)
+        for v in all_fixed_vars.values():
+            v.fix()
+
+    @abc.abstractmethod
+    def _add_sos_constraints(self, cons: List[SOSConstraintData]):
+        pass
+
+    def add_sos_constraints(self, cons: List[SOSConstraintData]):
+        for con in cons:
+            if con in self._vars_referenced_by_con:
+                raise ValueError(
+                    'constraint {name} has already been added'.format(name=con.name)
+                )
+            self._active_constraints[con] = tuple()
+            variables = con.get_variables()
+            self._check_for_new_vars(variables)
+            self._named_expressions[con] = []
+            self._vars_referenced_by_con[con] = variables
+            for v in variables:
+                self._referenced_variables[id(v)][1][con] = None
+        self._add_sos_constraints(cons)
+
+    @abc.abstractmethod
+    def _set_objective(self, obj: ObjectiveData):
+        pass
+
+    def set_objective(self, obj: ObjectiveData):
+        if self._objective is not None:
+            for v in self._vars_referenced_by_obj:
+                self._referenced_variables[id(v)][2] = None
+            self._check_to_remove_vars(self._vars_referenced_by_obj)
+            self._external_functions.pop(self._objective, None)
+        if obj is not None:
+            self._objective = obj
+            self._objective_expr = obj.expr
+            self._objective_sense = obj.sense
+            tmp = collect_vars_and_named_exprs(obj.expr)
+            named_exprs, variables, fixed_vars, external_functions = tmp
+            self._check_for_new_vars(variables)
+            self._obj_named_expressions = [(i, i.expr) for i in named_exprs]
+            if len(external_functions) > 0:
+                self._external_functions[obj] = external_functions
+            self._vars_referenced_by_obj = variables
+            for v in variables:
+                self._referenced_variables[id(v)][2] = obj
+            if not self.config.auto_updates.treat_fixed_vars_as_params:
+                for v in fixed_vars:
+                    v.unfix()
+            self._set_objective(obj)
+            for v in fixed_vars:
+                v.fix()
+        else:
+            self._vars_referenced_by_obj = []
+            self._objective = None
+            self._objective_expr = None
+            self._objective_sense = None
+            self._obj_named_expressions = []
+            self._set_objective(obj)
+
+    def add_block(self, block):
+        param_dict = {}
+        for p in block.component_objects(Param, descend_into=True):
+            if p.mutable:
+                for _p in p.values():
+                    param_dict[id(_p)] = _p
+        self.add_parameters(list(param_dict.values()))
+        self.add_constraints(
+            list(
+                block.component_data_objects(Constraint, descend_into=True, active=True)
+            )
+        )
+        self.add_sos_constraints(
+            list(
+                block.component_data_objects(
+                    SOSConstraint, descend_into=True, active=True
+                )
+            )
+        )
+        obj = get_objective(block)
+        if obj is not None:
+            self.set_objective(obj)
+
+    @abc.abstractmethod
+    def _remove_constraints(self, cons: List[ConstraintData]):
+        pass
+
+    def remove_constraints(self, cons: List[ConstraintData]):
+        self._remove_constraints(cons)
+        for con in cons:
+            if con not in self._named_expressions:
+                raise ValueError(
+                    'cannot remove constraint {name} - it was not added'.format(
+                        name=con.name
+                    )
+                )
+            for v in self._vars_referenced_by_con[con]:
+                self._referenced_variables[id(v)][0].pop(con)
+            self._check_to_remove_vars(self._vars_referenced_by_con[con])
+            del self._active_constraints[con]
+            del self._named_expressions[con]
+            self._external_functions.pop(con, None)
+            del self._vars_referenced_by_con[con]
+
+    @abc.abstractmethod
+    def _remove_sos_constraints(self, cons: List[SOSConstraintData]):
+        pass
+
+    def remove_sos_constraints(self, cons: List[SOSConstraintData]):
+        self._remove_sos_constraints(cons)
+        for con in cons:
+            if con not in self._vars_referenced_by_con:
+                raise ValueError(
+                    'cannot remove constraint {name} - it was not added'.format(
+                        name=con.name
+                    )
+                )
+            for v in self._vars_referenced_by_con[con]:
+                self._referenced_variables[id(v)][1].pop(con)
+            self._check_to_remove_vars(self._vars_referenced_by_con[con])
+            del self._active_constraints[con]
+            del self._named_expressions[con]
+            del self._vars_referenced_by_con[con]
+
+    @abc.abstractmethod
+    def _remove_variables(self, variables: List[VarData]):
+        pass
+
+    def remove_variables(self, variables: List[VarData]):
+        self._remove_variables(variables)
+        for v in variables:
+            v_id = id(v)
+            if v_id not in self._referenced_variables:
+                raise ValueError(
+                    'cannot remove variable {name} - it has not been added'.format(
+                        name=v.name
+                    )
+                )
+            cons_using, sos_using, obj_using = self._referenced_variables[v_id]
+            if cons_using or sos_using or (obj_using is not None):
+                raise ValueError(
+                    'cannot remove variable {name} - it is still being used by constraints or the objective'.format(
+                        name=v.name
+                    )
+                )
+            del self._referenced_variables[v_id]
+            del self._vars[v_id]
+
+    @abc.abstractmethod
+    def _remove_parameters(self, params: List[ParamData]):
+        pass
+
+    def remove_parameters(self, params: List[ParamData]):
+        self._remove_parameters(params)
+        for p in params:
+            del self._params[id(p)]
+
+    def remove_block(self, block):
+        self.remove_constraints(
+            list(
+                block.component_data_objects(
+                    ctype=Constraint, descend_into=True, active=True
+                )
+            )
+        )
+        self.remove_sos_constraints(
+            list(
+                block.component_data_objects(
+                    ctype=SOSConstraint, descend_into=True, active=True
+                )
+            )
+        )
+        self.remove_parameters(
+            list(
+                dict(
+                    (id(p), p)
+                    for p in block.component_data_objects(
+                        ctype=Param, descend_into=True
+                    )
+                ).values()
+            )
+        )
+
+    @abc.abstractmethod
+    def _update_variables(self, variables: List[VarData]):
+        pass
+
+    def update_variables(self, variables: List[VarData]):
+        for v in variables:
+            self._vars[id(v)] = (
+                v,
+                v._lb,
+                v._ub,
+                v.fixed,
+                v.domain.get_interval(),
+                v.value,
+            )
+        self._update_variables(variables)
+
+    @abc.abstractmethod
+    def update_parameters(self):
+        pass
+
+    def update(self, timer: HierarchicalTimer = None):
+        if timer is None:
+            timer = HierarchicalTimer()
+        config = self.config.auto_updates
+        new_vars = []
+        old_vars = []
+        new_params = []
+        old_params = []
+        new_cons = []
+        old_cons = []
+        old_sos = []
+        new_sos = []
+        current_vars_dict = {}
+        current_cons_dict = {}
+        current_sos_dict = {}
+        timer.start('vars')
+        if config.update_vars:
+            start_vars = {v_id: v_tuple[0] for v_id, v_tuple in self._vars.items()}
+        timer.stop('vars')
+        timer.start('params')
+        if config.check_for_new_or_removed_params:
+            current_params_dict = {}
+            for p in self._model.component_objects(Param, descend_into=True):
+                if p.mutable:
+                    for _p in p.values():
+                        current_params_dict[id(_p)] = _p
+            for p_id, p in current_params_dict.items():
+                if p_id not in self._params:
+                    new_params.append(p)
+            for p_id, p in self._params.items():
+                if p_id not in current_params_dict:
+                    old_params.append(p)
+        timer.stop('params')
+        timer.start('cons')
+        if config.check_for_new_or_removed_constraints or config.update_constraints:
+            current_cons_dict = {
+                c: None
+                for c in self._model.component_data_objects(
+                    Constraint, descend_into=True, active=True
+                )
+            }
+            current_sos_dict = {
+                c: None
+                for c in self._model.component_data_objects(
+                    SOSConstraint, descend_into=True, active=True
+                )
+            }
+            for c in current_cons_dict.keys():
+                if c not in self._vars_referenced_by_con:
+                    new_cons.append(c)
+            for c in current_sos_dict.keys():
+                if c not in self._vars_referenced_by_con:
+                    new_sos.append(c)
+            for c in self._vars_referenced_by_con.keys():
+                if c not in current_cons_dict and c not in current_sos_dict:
+                    if (c.ctype is Constraint) or (
+                        c.ctype is None and isinstance(c, ConstraintData)
+                    ):
+                        old_cons.append(c)
+                    else:
+                        assert (c.ctype is SOSConstraint) or (
+                            c.ctype is None and isinstance(c, SOSConstraintData)
+                        )
+                        old_sos.append(c)
+        self.remove_constraints(old_cons)
+        self.remove_sos_constraints(old_sos)
+        timer.stop('cons')
+        timer.start('params')
+        self.remove_parameters(old_params)
+
+        # sticking this between removal and addition
+        # is important so that we don't do unnecessary work
+        if config.update_parameters:
+            self.update_parameters()
+
+        self.add_parameters(new_params)
+        timer.stop('params')
+        timer.start('vars')
+        self.add_variables(new_vars)
+        timer.stop('vars')
+        timer.start('cons')
+        self.add_constraints(new_cons)
+        self.add_sos_constraints(new_sos)
+        new_cons_set = set(new_cons)
+        new_sos_set = set(new_sos)
+        new_vars_set = set(id(v) for v in new_vars)
+        cons_to_remove_and_add = {}
+        need_to_set_objective = False
+        if config.update_constraints:
+            cons_to_update = []
+            sos_to_update = []
+            for c in current_cons_dict.keys():
+                if c not in new_cons_set:
+                    cons_to_update.append(c)
+            for c in current_sos_dict.keys():
+                if c not in new_sos_set:
+                    sos_to_update.append(c)
+            for c in cons_to_update:
+                lower, body, upper = self._active_constraints[c]
+                new_lower, new_body, new_upper = c.lower, c.body, c.upper
+                if new_body is not body:
+                    cons_to_remove_and_add[c] = None
+                    continue
+                if new_lower is not lower:
+                    if (
+                        type(new_lower) is NumericConstant
+                        and type(lower) is NumericConstant
+                        and new_lower.value == lower.value
+                    ):
+                        pass
+                    else:
+                        cons_to_remove_and_add[c] = None
+                        continue
+                if new_upper is not upper:
+                    if (
+                        type(new_upper) is NumericConstant
+                        and type(upper) is NumericConstant
+                        and new_upper.value == upper.value
+                    ):
+                        pass
+                    else:
+                        cons_to_remove_and_add[c] = None
+                        continue
+            self.remove_sos_constraints(sos_to_update)
+            self.add_sos_constraints(sos_to_update)
+        timer.stop('cons')
+        timer.start('vars')
+        if config.update_vars:
+            end_vars = {v_id: v_tuple[0] for v_id, v_tuple in self._vars.items()}
+            vars_to_check = [v for v_id, v in end_vars.items() if v_id in start_vars]
+        if config.update_vars:
+            vars_to_update = []
+            for v in vars_to_check:
+                _v, lb, ub, fixed, domain_interval, value = self._vars[id(v)]
+                if (fixed != v.fixed) or (fixed and (value != v.value)):
+                    vars_to_update.append(v)
+                    if self.config.auto_updates.treat_fixed_vars_as_params:
+                        for c in self._referenced_variables[id(v)][0]:
+                            cons_to_remove_and_add[c] = None
+                        if self._referenced_variables[id(v)][2] is not None:
+                            need_to_set_objective = True
+                elif lb is not v._lb:
+                    vars_to_update.append(v)
+                elif ub is not v._ub:
+                    vars_to_update.append(v)
+                elif domain_interval != v.domain.get_interval():
+                    vars_to_update.append(v)
+            self.update_variables(vars_to_update)
+        timer.stop('vars')
+        timer.start('cons')
+        cons_to_remove_and_add = list(cons_to_remove_and_add.keys())
+        self.remove_constraints(cons_to_remove_and_add)
+        self.add_constraints(cons_to_remove_and_add)
+        timer.stop('cons')
+        timer.start('named expressions')
+        if config.update_named_expressions:
+            cons_to_update = []
+            for c, expr_list in self._named_expressions.items():
+                if c in new_cons_set:
+                    continue
+                for named_expr, old_expr in expr_list:
+                    if named_expr.expr is not old_expr:
+                        cons_to_update.append(c)
+                        break
+            self.remove_constraints(cons_to_update)
+            self.add_constraints(cons_to_update)
+            for named_expr, old_expr in self._obj_named_expressions:
+                if named_expr.expr is not old_expr:
+                    need_to_set_objective = True
+                    break
+        timer.stop('named expressions')
+        timer.start('objective')
+        if self.config.auto_updates.check_for_new_objective:
+            pyomo_obj = get_objective(self._model)
+            if pyomo_obj is not self._objective:
+                need_to_set_objective = True
+        else:
+            pyomo_obj = self._objective
+        if self.config.auto_updates.update_objective:
+            if pyomo_obj is not None and pyomo_obj.expr is not self._objective_expr:
+                need_to_set_objective = True
+            elif pyomo_obj is not None and pyomo_obj.sense is not self._objective_sense:
+                # we can definitely do something faster here than resetting the whole objective
+                need_to_set_objective = True
+        if need_to_set_objective:
+            self.set_objective(pyomo_obj)
+        timer.stop('objective')
+
+        # this has to be done after the objective and constraints in case the
+        # old objective/constraints use old variables
+        timer.start('vars')
+        self.remove_variables(old_vars)
+        timer.stop('vars')
diff --git a/pyomo/contrib/solver/plugins.py b/pyomo/contrib/solver/plugins.py
new file mode 100644
index 00000000000..82c10a32fd8
--- /dev/null
+++ b/pyomo/contrib/solver/plugins.py
@@ -0,0 +1,30 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+
+from .factory import SolverFactory
+from .ipopt import Ipopt
+from .gurobi import Gurobi
+from .gurobi_direct import GurobiDirect
+
+
+def load():
+    SolverFactory.register(
+        name='ipopt', legacy_name='ipopt_v2', doc='The IPOPT NLP solver'
+    )(Ipopt)
+    SolverFactory.register(
+        name='gurobi', legacy_name='gurobi_v2', doc='Persistent interface to Gurobi'
+    )(Gurobi)
+    SolverFactory.register(
+        name='gurobi_direct',
+        legacy_name='gurobi_direct_v2',
+        doc='Direct (scipy-based) interface to Gurobi',
+    )(GurobiDirect)
diff --git a/pyomo/contrib/solver/results.py b/pyomo/contrib/solver/results.py
new file mode 100644
index 00000000000..cbc04681235
--- /dev/null
+++ b/pyomo/contrib/solver/results.py
@@ -0,0 +1,353 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import enum
+from typing import Optional, Tuple
+from datetime import datetime
+
+from pyomo.common.config import (
+    ConfigDict,
+    ConfigValue,
+    IsInstance,
+    NonNegativeInt,
+    In,
+    NonNegativeFloat,
+    ADVANCED_OPTION,
+)
+from pyomo.opt.results.solution import SolutionStatus as LegacySolutionStatus
+from pyomo.opt.results.solver import (
+    TerminationCondition as LegacyTerminationCondition,
+    SolverStatus as LegacySolverStatus,
+)
+
+
+class TerminationCondition(enum.Enum):
+    """
+    An Enum that enumerates all possible exit statuses for a solver call.
+
+    Attributes
+    ----------
+    convergenceCriteriaSatisfied: 0
+        The solver exited because convergence criteria of the problem were
+        satisfied.
+    maxTimeLimit: 1
+        The solver exited due to reaching a specified time limit.
+    iterationLimit: 2
+        The solver exited due to reaching a specified iteration limit.
+    objectiveLimit: 3
+        The solver exited due to reaching an objective limit. For example,
+        in Gurobi, the exit message "Optimal objective for model was proven to
+        be worse than the value specified in the Cutoff parameter" would map
+        to objectiveLimit.
+    minStepLength: 4
+        The solver exited due to a minimum step length.
+        Minimum step length reached may mean that the problem is infeasible or
+        that the problem is feasible but the solver could not converge.
+    unbounded: 5
+        The solver exited because the problem has been found to be unbounded.
+    provenInfeasible: 6
+        The solver exited because the problem has been proven infeasible.
+    locallyInfeasible: 7
+        The solver exited because no feasible solution was found to the
+        submitted problem, but it could not be proven that no such solution exists.
+    infeasibleOrUnbounded: 8
+        Some solvers do not specify between infeasibility or unboundedness and
+        instead return that one or the other has occurred. For example, in
+        Gurobi, this may occur because there are some steps in presolve that
+        prevent Gurobi from distinguishing between infeasibility and unboundedness.
+    error: 9
+        The solver exited with some error. The error message will also be
+        captured and returned.
+    interrupted: 10
+        The solver was interrupted while running.
+    licensingProblems: 11
+        The solver experienced issues with licensing. This could be that no
+        license was found, the license is of the wrong type for the problem (e.g.,
+        problem is too big for type of license), or there was an issue contacting
+        a licensing server.
+    emptyModel: 12
+        The model being solved did not have any variables
+    unknown: 42
+        All other unrecognized exit statuses fall in this category.
+    """
+
+    convergenceCriteriaSatisfied = 0
+
+    maxTimeLimit = 1
+
+    iterationLimit = 2
+
+    objectiveLimit = 3
+
+    minStepLength = 4
+
+    unbounded = 5
+
+    provenInfeasible = 6
+
+    locallyInfeasible = 7
+
+    infeasibleOrUnbounded = 8
+
+    error = 9
+
+    interrupted = 10
+
+    licensingProblems = 11
+
+    emptyModel = 12
+
+    unknown = 42
+
+
+class SolutionStatus(enum.Enum):
+    """
+    An enumeration for interpreting the result of a termination. This describes the designated
+    status by the solver to be loaded back into the model.
+
+    Attributes
+    ----------
+    noSolution: 0
+        No (single) solution was found; possible that a population of solutions
+        was returned.
+    infeasible: 10
+        Solution point does not satisfy some domains and/or constraints.
+    feasible: 20
+        A solution for which all of the constraints in the model are satisfied.
+    optimal: 30
+        A feasible solution where the objective function reaches its specified
+        sense (e.g., maximum, minimum)
+    """
+
+    noSolution = 0
+
+    infeasible = 10
+
+    feasible = 20
+
+    optimal = 30
+
+
+class Results(ConfigDict):
+    """
+    Attributes
+    ----------
+    solution_loader: SolutionLoaderBase
+        Object for loading the solution back into the model.
+    termination_condition: :class:`TerminationCondition<pyomo.contrib.solver.results.TerminationCondition>`
+        The reason the solver exited. This is a member of the
+        TerminationCondition enum.
+    solution_status: :class:`SolutionStatus<pyomo.contrib.solver.results.SolutionStatus>`
+        The result of the solve call. This is a member of the SolutionStatus
+        enum.
+    incumbent_objective: float
+        If a feasible solution was found, this is the objective value of
+        the best solution found. If no feasible solution was found, this is
+        None.
+    objective_bound: float
+        The best objective bound found. For minimization problems, this is
+        the lower bound. For maximization problems, this is the upper bound.
+        For solvers that do not provide an objective bound, this should be -inf
+        (minimization) or inf (maximization)
+    solver_name: str
+        The name of the solver in use.
+    solver_version: tuple
+        A tuple representing the version of the solver in use.
+    iteration_count: int
+        The total number of iterations.
+    timing_info: ConfigDict
+        A ConfigDict containing three pieces of information:
+            - ``start_timestamp``: UTC timestamp of when run was initiated
+            - ``wall_time``: elapsed wall clock time for entire process
+            - ``timer``: a HierarchicalTimer object containing timing data about the solve
+
+        Specific solvers may add other relevant timing information, as appropriate.
+    extra_info: ConfigDict
+        A ConfigDict to store extra information such as solver messages.
+    solver_configuration: ConfigDict
+        A copy of the SolverConfig ConfigDict, for later inspection/reproducibility.
+    solver_log: str
+        (ADVANCED OPTION) Any solver log messages.
+    """
+
+    def __init__(
+        self,
+        description=None,
+        doc=None,
+        implicit=False,
+        implicit_domain=None,
+        visibility=0,
+    ):
+        super().__init__(
+            description=description,
+            doc=doc,
+            implicit=implicit,
+            implicit_domain=implicit_domain,
+            visibility=visibility,
+        )
+
+        self.solution_loader = self.declare(
+            'solution_loader',
+            ConfigValue(
+                description="Object for loading the solution back into the model."
+            ),
+        )
+        self.termination_condition: TerminationCondition = self.declare(
+            'termination_condition',
+            ConfigValue(
+                domain=In(TerminationCondition),
+                default=TerminationCondition.unknown,
+                description="The reason the solver exited. This is a member of the "
+                "TerminationCondition enum.",
+            ),
+        )
+        self.solution_status: SolutionStatus = self.declare(
+            'solution_status',
+            ConfigValue(
+                domain=In(SolutionStatus),
+                default=SolutionStatus.noSolution,
+                description="The result of the solve call. This is a member of "
+                "the SolutionStatus enum.",
+            ),
+        )
+        self.incumbent_objective: Optional[float] = self.declare(
+            'incumbent_objective',
+            ConfigValue(
+                domain=float,
+                default=None,
+                description="If a feasible solution was found, this is the objective "
+                "value of the best solution found. If no feasible solution was found, this is None.",
+            ),
+        )
+        self.objective_bound: Optional[float] = self.declare(
+            'objective_bound',
+            ConfigValue(
+                domain=float,
+                default=None,
+                description="The best objective bound found. For minimization problems, "
+                "this is the lower bound. For maximization problems, this is the "
+                "upper bound. For solvers that do not provide an objective bound, "
+                "this should be -inf (minimization) or inf (maximization)",
+            ),
+        )
+        self.solver_name: Optional[str] = self.declare(
+            'solver_name',
+            ConfigValue(domain=str, description="The name of the solver in use."),
+        )
+        self.solver_version: Optional[Tuple[int, ...]] = self.declare(
+            'solver_version',
+            ConfigValue(
+                domain=tuple,
+                description="A tuple representing the version of the solver in use.",
+            ),
+        )
+        self.iteration_count: Optional[int] = self.declare(
+            'iteration_count',
+            ConfigValue(
+                domain=NonNegativeInt,
+                default=None,
+                description="The total number of iterations.",
+            ),
+        )
+        self.timing_info: ConfigDict = self.declare(
+            'timing_info', ConfigDict(implicit=True)
+        )
+
+        self.timing_info.start_timestamp: datetime = self.timing_info.declare(
+            'start_timestamp',
+            ConfigValue(
+                domain=IsInstance(datetime),
+                description="UTC timestamp of when run was initiated.",
+            ),
+        )
+        self.timing_info.wall_time: Optional[float] = self.timing_info.declare(
+            'wall_time',
+            ConfigValue(
+                domain=NonNegativeFloat,
+                description="Elapsed wall clock time for entire process.",
+            ),
+        )
+        self.extra_info: ConfigDict = self.declare(
+            'extra_info', ConfigDict(implicit=True)
+        )
+        self.solver_configuration: ConfigDict = self.declare(
+            'solver_configuration',
+            ConfigValue(
+                description="A copy of the config object used in the solve call.",
+                visibility=ADVANCED_OPTION,
+            ),
+        )
+        self.solver_log: str = self.declare(
+            'solver_log',
+            ConfigValue(
+                domain=str,
+                default=None,
+                visibility=ADVANCED_OPTION,
+                description="Any solver log messages.",
+            ),
+        )
+
+    def display(
+        self, content_filter=None, indent_spacing=2, ostream=None, visibility=0
+    ):
+        return super().display(content_filter, indent_spacing, ostream, visibility)
+
+
+# Everything below here preserves backwards compatibility
+
+legacy_termination_condition_map = {
+    TerminationCondition.unknown: LegacyTerminationCondition.unknown,
+    TerminationCondition.maxTimeLimit: LegacyTerminationCondition.maxTimeLimit,
+    TerminationCondition.iterationLimit: LegacyTerminationCondition.maxIterations,
+    TerminationCondition.objectiveLimit: LegacyTerminationCondition.minFunctionValue,
+    TerminationCondition.minStepLength: LegacyTerminationCondition.minStepLength,
+    TerminationCondition.convergenceCriteriaSatisfied: LegacyTerminationCondition.optimal,
+    TerminationCondition.unbounded: LegacyTerminationCondition.unbounded,
+    TerminationCondition.provenInfeasible: LegacyTerminationCondition.infeasible,
+    TerminationCondition.locallyInfeasible: LegacyTerminationCondition.infeasible,
+    TerminationCondition.infeasibleOrUnbounded: LegacyTerminationCondition.infeasibleOrUnbounded,
+    TerminationCondition.error: LegacyTerminationCondition.error,
+    TerminationCondition.interrupted: LegacyTerminationCondition.resourceInterrupt,
+    TerminationCondition.licensingProblems: LegacyTerminationCondition.licensingProblems,
+}
+
+
+legacy_solver_status_map = {
+    TerminationCondition.unknown: LegacySolverStatus.unknown,
+    TerminationCondition.maxTimeLimit: LegacySolverStatus.aborted,
+    TerminationCondition.iterationLimit: LegacySolverStatus.aborted,
+    TerminationCondition.objectiveLimit: LegacySolverStatus.aborted,
+    TerminationCondition.minStepLength: LegacySolverStatus.error,
+    TerminationCondition.convergenceCriteriaSatisfied: LegacySolverStatus.ok,
+    TerminationCondition.unbounded: LegacySolverStatus.error,
+    TerminationCondition.provenInfeasible: LegacySolverStatus.error,
+    TerminationCondition.locallyInfeasible: LegacySolverStatus.error,
+    TerminationCondition.infeasibleOrUnbounded: LegacySolverStatus.error,
+    TerminationCondition.error: LegacySolverStatus.error,
+    TerminationCondition.interrupted: LegacySolverStatus.aborted,
+    TerminationCondition.licensingProblems: LegacySolverStatus.error,
+}
+
+
+legacy_solution_status_map = {
+    SolutionStatus.noSolution: LegacySolutionStatus.unknown,
+    SolutionStatus.noSolution: LegacySolutionStatus.stoppedByLimit,
+    SolutionStatus.noSolution: LegacySolutionStatus.error,
+    SolutionStatus.noSolution: LegacySolutionStatus.other,
+    SolutionStatus.noSolution: LegacySolutionStatus.unsure,
+    SolutionStatus.noSolution: LegacySolutionStatus.unbounded,
+    SolutionStatus.optimal: LegacySolutionStatus.locallyOptimal,
+    SolutionStatus.optimal: LegacySolutionStatus.globallyOptimal,
+    SolutionStatus.optimal: LegacySolutionStatus.optimal,
+    SolutionStatus.infeasible: LegacySolutionStatus.infeasible,
+    SolutionStatus.feasible: LegacySolutionStatus.feasible,
+    SolutionStatus.feasible: LegacySolutionStatus.bestSoFar,
+}
diff --git a/pyomo/contrib/solver/sol_reader.py b/pyomo/contrib/solver/sol_reader.py
new file mode 100644
index 00000000000..41d840f8d07
--- /dev/null
+++ b/pyomo/contrib/solver/sol_reader.py
@@ -0,0 +1,207 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+
+from typing import Tuple, Dict, Any, List
+import io
+
+from pyomo.common.errors import DeveloperError, PyomoException
+from pyomo.repn.plugins.nl_writer import NLWriterInfo
+from pyomo.contrib.solver.results import Results, SolutionStatus, TerminationCondition
+
+
+class SolFileData:
+    def __init__(self) -> None:
+        self.primals: List[float] = list()
+        self.duals: List[float] = list()
+        self.var_suffixes: Dict[str, Dict[int, Any]] = dict()
+        self.con_suffixes: Dict[str, Dict[Any]] = dict()
+        self.obj_suffixes: Dict[str, Dict[int, Any]] = dict()
+        self.problem_suffixes: Dict[str, List[Any]] = dict()
+        self.other: List(str) = list()
+
+
+def parse_sol_file(
+    sol_file: io.TextIOBase, nl_info: NLWriterInfo, result: Results
+) -> Tuple[Results, SolFileData]:
+    sol_data = SolFileData()
+
+    #
+    # Some solvers (minto) do not write a message.  We will assume
+    # all non-blank lines up to the 'Options' line is the message.
+    # For backwards compatibility and general safety, we will parse all
+    # lines until "Options" appears. Anything before "Options" we will
+    # consider to be the solver message.
+    message = []
+    for line in sol_file:
+        if not line:
+            break
+        line = line.strip()
+        if "Options" in line:
+            break
+        message.append(line)
+    message = '\n'.join(message)
+    # Once "Options" appears, we must now read the content under it.
+    model_objects = []
+    if "Options" in line:
+        line = sol_file.readline()
+        number_of_options = int(line)
+        # We are adding in this DeveloperError to see if the alternative case
+        # is ever actually hit in the wild. In a previous iteration of the sol
+        # reader, there was logic to check for the number of options, but it
+        # was uncovered by tests and unclear if actually necessary.
+        if number_of_options > 4:
+            raise DeveloperError(
+                """
+The sol file reader has hit an unexpected error while parsing. The number of
+options recorded is greater than 4. Please report this error to the Pyomo
+developers.
+                                 """
+            )
+        for i in range(number_of_options + 4):
+            line = sol_file.readline()
+            model_objects.append(int(line))
+    else:
+        raise PyomoException("ERROR READING `sol` FILE. No 'Options' line found.")
+    # Identify the total number of variables and constraints
+    number_of_cons = model_objects[number_of_options + 1]
+    number_of_vars = model_objects[number_of_options + 3]
+    assert number_of_cons == len(nl_info.constraints)
+    assert number_of_vars == len(nl_info.variables)
+
+    duals = [float(sol_file.readline()) for i in range(number_of_cons)]
+    variable_vals = [float(sol_file.readline()) for i in range(number_of_vars)]
+
+    # Parse the exit code line and capture it
+    exit_code = [0, 0]
+    line = sol_file.readline()
+    if line and ('objno' in line):
+        exit_code_line = line.split()
+        if len(exit_code_line) != 3:
+            raise PyomoException(
+                f"ERROR READING `sol` FILE. Expected two numbers in `objno` line; received {line}."
+            )
+        exit_code = [int(exit_code_line[1]), int(exit_code_line[2])]
+    else:
+        raise PyomoException(
+            f"ERROR READING `sol` FILE. Expected `objno`; received {line}."
+        )
+    result.extra_info.solver_message = message.strip().replace('\n', '; ')
+    exit_code_message = ''
+    if (exit_code[1] >= 0) and (exit_code[1] <= 99):
+        result.solution_status = SolutionStatus.optimal
+        result.termination_condition = TerminationCondition.convergenceCriteriaSatisfied
+    elif (exit_code[1] >= 100) and (exit_code[1] <= 199):
+        exit_code_message = "Optimal solution indicated, but ERROR LIKELY!"
+        result.solution_status = SolutionStatus.feasible
+        result.termination_condition = TerminationCondition.error
+    elif (exit_code[1] >= 200) and (exit_code[1] <= 299):
+        exit_code_message = "INFEASIBLE SOLUTION: constraints cannot be satisfied!"
+        result.solution_status = SolutionStatus.infeasible
+        result.termination_condition = TerminationCondition.locallyInfeasible
+    elif (exit_code[1] >= 300) and (exit_code[1] <= 399):
+        exit_code_message = (
+            "UNBOUNDED PROBLEM: the objective can be improved without limit!"
+        )
+        result.solution_status = SolutionStatus.noSolution
+        result.termination_condition = TerminationCondition.unbounded
+    elif (exit_code[1] >= 400) and (exit_code[1] <= 499):
+        exit_code_message = (
+            "EXCEEDED MAXIMUM NUMBER OF ITERATIONS: the solver "
+            "was stopped by a limit that you set!"
+        )
+        result.solution_status = SolutionStatus.infeasible
+        result.termination_condition = (
+            TerminationCondition.iterationLimit
+        )  # this is not always correct
+    elif (exit_code[1] >= 500) and (exit_code[1] <= 599):
+        exit_code_message = (
+            "FAILURE: the solver stopped by an error condition "
+            "in the solver routines!"
+        )
+        result.termination_condition = TerminationCondition.error
+
+    if result.extra_info.solver_message:
+        if exit_code_message:
+            result.extra_info.solver_message += '; ' + exit_code_message
+    else:
+        result.extra_info.solver_message = exit_code_message
+
+    if result.solution_status != SolutionStatus.noSolution:
+        sol_data.primals = variable_vals
+        sol_data.duals = duals
+        ### Read suffixes ###
+        line = sol_file.readline()
+        while line:
+            line = line.strip()
+            if line == "":
+                continue
+            line = line.split()
+            # Some sort of garbage we tag onto the solver message, assuming we are past the suffixes
+            if line[0] != 'suffix':
+                # We assume this is the start of a
+                # section like kestrel_option, which
+                # comes after all suffixes.
+                remaining = ""
+                line = sol_file.readline()
+                while line:
+                    remaining += line.strip() + "; "
+                    line = sol_file.readline()
+                result.extra_info.solver_message += remaining
+                break
+            read_data_type = int(line[1])
+            data_type = read_data_type & 3  # 0-var, 1-con, 2-obj, 3-prob
+            convert_function = int
+            if (read_data_type & 4) == 4:
+                convert_function = float
+            number_of_entries = int(line[2])
+            # The third entry is name length, and it is length+1. This is unnecessary
+            # except for data validation.
+            # The fourth entry is table "length", e.g., memory size.
+            number_of_string_lines = int(line[5])
+            suffix_name = sol_file.readline().strip()
+            # Add any arbitrary string lines to the "other" list
+            for line in range(number_of_string_lines):
+                sol_data.other.append(sol_file.readline())
+            if data_type == 0:  # Var
+                sol_data.var_suffixes[suffix_name] = dict()
+                for cnt in range(number_of_entries):
+                    suf_line = sol_file.readline().split()
+                    var_ndx = int(suf_line[0])
+                    sol_data.var_suffixes[suffix_name][var_ndx] = convert_function(
+                        suf_line[1]
+                    )
+            elif data_type == 1:  # Con
+                sol_data.con_suffixes[suffix_name] = dict()
+                for cnt in range(number_of_entries):
+                    suf_line = sol_file.readline().split()
+                    con_ndx = int(suf_line[0])
+                    sol_data.con_suffixes[suffix_name][con_ndx] = convert_function(
+                        suf_line[1]
+                    )
+            elif data_type == 2:  # Obj
+                sol_data.obj_suffixes[suffix_name] = dict()
+                for cnt in range(number_of_entries):
+                    suf_line = sol_file.readline().split()
+                    obj_ndx = int(suf_line[0])
+                    sol_data.obj_suffixes[suffix_name][obj_ndx] = convert_function(
+                        suf_line[1]
+                    )
+            elif data_type == 3:  # Prob
+                sol_data.problem_suffixes[suffix_name] = list()
+                for cnt in range(number_of_entries):
+                    suf_line = sol_file.readline().split()
+                    sol_data.problem_suffixes[suffix_name].append(
+                        convert_function(suf_line[1])
+                    )
+            line = sol_file.readline()
+
+    return result, sol_data
diff --git a/pyomo/contrib/solver/solution.py b/pyomo/contrib/solver/solution.py
new file mode 100644
index 00000000000..a3e66475982
--- /dev/null
+++ b/pyomo/contrib/solver/solution.py
@@ -0,0 +1,237 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import abc
+from typing import Sequence, Dict, Optional, Mapping, NoReturn
+
+from pyomo.core.base.constraint import ConstraintData
+from pyomo.core.base.var import VarData
+from pyomo.core.expr import value
+from pyomo.common.collections import ComponentMap
+from pyomo.common.errors import DeveloperError
+from pyomo.core.staleflag import StaleFlagManager
+from pyomo.contrib.solver.sol_reader import SolFileData
+from pyomo.repn.plugins.nl_writer import NLWriterInfo
+from pyomo.core.expr.visitor import replace_expressions
+
+
+class SolutionLoaderBase(abc.ABC):
+    """
+    Base class for all future SolutionLoader classes.
+
+    Intent of this class and its children is to load the solution back into the model.
+    """
+
+    def load_vars(self, vars_to_load: Optional[Sequence[VarData]] = None) -> NoReturn:
+        """
+        Load the solution of the primal variables into the value attribute of the variables.
+
+        Parameters
+        ----------
+        vars_to_load: list
+            The minimum set of variables whose solution should be loaded. If vars_to_load is None, then the solution
+            to all primal variables will be loaded. Even if vars_to_load is specified, the values of other
+            variables may also be loaded depending on the interface.
+        """
+        for v, val in self.get_primals(vars_to_load=vars_to_load).items():
+            v.set_value(val, skip_validation=True)
+        StaleFlagManager.mark_all_as_stale(delayed=True)
+
+    @abc.abstractmethod
+    def get_primals(
+        self, vars_to_load: Optional[Sequence[VarData]] = None
+    ) -> Mapping[VarData, float]:
+        """
+        Returns a ComponentMap mapping variable to var value.
+
+        Parameters
+        ----------
+        vars_to_load: list
+            A list of the variables whose solution value should be retrieved. If vars_to_load is None,
+            then the values for all variables will be retrieved.
+
+        Returns
+        -------
+        primals: ComponentMap
+            Maps variables to solution values
+        """
+
+    def get_duals(
+        self, cons_to_load: Optional[Sequence[ConstraintData]] = None
+    ) -> Dict[ConstraintData, float]:
+        """
+        Returns a dictionary mapping constraint to dual value.
+
+        Parameters
+        ----------
+        cons_to_load: list
+            A list of the constraints whose duals should be retrieved. If cons_to_load is None, then the duals for all
+            constraints will be retrieved.
+
+        Returns
+        -------
+        duals: dict
+            Maps constraints to dual values
+        """
+        raise NotImplementedError(f'{type(self)} does not support the get_duals method')
+
+    def get_reduced_costs(
+        self, vars_to_load: Optional[Sequence[VarData]] = None
+    ) -> Mapping[VarData, float]:
+        """
+        Returns a ComponentMap mapping variable to reduced cost.
+
+        Parameters
+        ----------
+        vars_to_load: list
+            A list of the variables whose reduced cost should be retrieved. If vars_to_load is None, then the
+            reduced costs for all variables will be loaded.
+
+        Returns
+        -------
+        reduced_costs: ComponentMap
+            Maps variables to reduced costs
+        """
+        raise NotImplementedError(
+            f'{type(self)} does not support the get_reduced_costs method'
+        )
+
+
+class PersistentSolutionLoader(SolutionLoaderBase):
+    def __init__(self, solver):
+        self._solver = solver
+        self._valid = True
+
+    def _assert_solution_still_valid(self):
+        if not self._valid:
+            raise RuntimeError('The results in the solver are no longer valid.')
+
+    def get_primals(self, vars_to_load=None):
+        self._assert_solution_still_valid()
+        return self._solver._get_primals(vars_to_load=vars_to_load)
+
+    def get_duals(
+        self, cons_to_load: Optional[Sequence[ConstraintData]] = None
+    ) -> Dict[ConstraintData, float]:
+        self._assert_solution_still_valid()
+        return self._solver._get_duals(cons_to_load=cons_to_load)
+
+    def get_reduced_costs(
+        self, vars_to_load: Optional[Sequence[VarData]] = None
+    ) -> Mapping[VarData, float]:
+        self._assert_solution_still_valid()
+        return self._solver._get_reduced_costs(vars_to_load=vars_to_load)
+
+    def invalidate(self):
+        self._valid = False
+
+
+class SolSolutionLoader(SolutionLoaderBase):
+    def __init__(self, sol_data: SolFileData, nl_info: NLWriterInfo) -> None:
+        self._sol_data = sol_data
+        self._nl_info = nl_info
+
+    def load_vars(self, vars_to_load: Optional[Sequence[VarData]] = None) -> NoReturn:
+        if self._nl_info is None:
+            raise RuntimeError(
+                'Solution loader does not currently have a valid solution. Please '
+                'check results.TerminationCondition and/or results.SolutionStatus.'
+            )
+        if self._sol_data is None:
+            assert len(self._nl_info.variables) == 0
+        else:
+            if self._nl_info.scaling:
+                for v, val, scale in zip(
+                    self._nl_info.variables,
+                    self._sol_data.primals,
+                    self._nl_info.scaling.variables,
+                ):
+                    v.set_value(val / scale, skip_validation=True)
+            else:
+                for v, val in zip(self._nl_info.variables, self._sol_data.primals):
+                    v.set_value(val, skip_validation=True)
+
+        for v, v_expr in self._nl_info.eliminated_vars:
+            v.value = value(v_expr)
+
+        StaleFlagManager.mark_all_as_stale(delayed=True)
+
+    def get_primals(
+        self, vars_to_load: Optional[Sequence[VarData]] = None
+    ) -> Mapping[VarData, float]:
+        if self._nl_info is None:
+            raise RuntimeError(
+                'Solution loader does not currently have a valid solution. Please '
+                'check results.TerminationCondition and/or results.SolutionStatus.'
+            )
+        val_map = dict()
+        if self._sol_data is None:
+            assert len(self._nl_info.variables) == 0
+        else:
+            if self._nl_info.scaling is None:
+                scale_list = [1] * len(self._nl_info.variables)
+            else:
+                scale_list = self._nl_info.scaling.variables
+            for v, val, scale in zip(
+                self._nl_info.variables, self._sol_data.primals, scale_list
+            ):
+                val_map[id(v)] = val / scale
+
+        for v, v_expr in self._nl_info.eliminated_vars:
+            val = replace_expressions(v_expr, substitution_map=val_map)
+            v_id = id(v)
+            val_map[v_id] = val
+
+        res = ComponentMap()
+        if vars_to_load is None:
+            vars_to_load = self._nl_info.variables + [
+                v for v, _ in self._nl_info.eliminated_vars
+            ]
+        for v in vars_to_load:
+            res[v] = val_map[id(v)]
+
+        return res
+
+    def get_duals(
+        self, cons_to_load: Optional[Sequence[ConstraintData]] = None
+    ) -> Dict[ConstraintData, float]:
+        if self._nl_info is None:
+            raise RuntimeError(
+                'Solution loader does not currently have a valid solution. Please '
+                'check results.TerminationCondition and/or results.SolutionStatus.'
+            )
+        if len(self._nl_info.eliminated_vars) > 0:
+            raise NotImplementedError(
+                'For now, turn presolve off (opt.config.writer_config.linear_presolve=False) '
+                'to get dual variable values.'
+            )
+        if self._sol_data is None:
+            raise DeveloperError(
+                "Solution data is empty. This should not "
+                "have happened. Report this error to the Pyomo Developers."
+            )
+        res = dict()
+        if self._nl_info.scaling is None:
+            scale_list = [1] * len(self._nl_info.constraints)
+            obj_scale = 1
+        else:
+            scale_list = self._nl_info.scaling.constraints
+            obj_scale = self._nl_info.scaling.objectives[0]
+        if cons_to_load is None:
+            cons_to_load = set(self._nl_info.constraints)
+        else:
+            cons_to_load = set(cons_to_load)
+        for c, val, scale in zip(
+            self._nl_info.constraints, self._sol_data.duals, scale_list
+        ):
+            if c in cons_to_load:
+                res[c] = val * scale / obj_scale
+        return res
diff --git a/pyomo/contrib/solver/tests/__init__.py b/pyomo/contrib/solver/tests/__init__.py
new file mode 100644
index 00000000000..a4a626013c4
--- /dev/null
+++ b/pyomo/contrib/solver/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/solver/tests/solvers/__init__.py b/pyomo/contrib/solver/tests/solvers/__init__.py
new file mode 100644
index 00000000000..a4a626013c4
--- /dev/null
+++ b/pyomo/contrib/solver/tests/solvers/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/solver/tests/solvers/test_gurobi_persistent.py b/pyomo/contrib/solver/tests/solvers/test_gurobi_persistent.py
new file mode 100644
index 00000000000..2f281e2abf0
--- /dev/null
+++ b/pyomo/contrib/solver/tests/solvers/test_gurobi_persistent.py
@@ -0,0 +1,700 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import pyomo.common.unittest as unittest
+import pyomo.environ as pe
+from pyomo.contrib.solver.gurobi import Gurobi
+from pyomo.contrib.solver.results import SolutionStatus
+from pyomo.core.expr.taylor_series import taylor_series_expansion
+
+
+opt = Gurobi()
+if not opt.available():
+    raise unittest.SkipTest
+import gurobipy
+
+
+def create_pmedian_model():
+    d_dict = {
+        (1, 1): 1.777356642700564,
+        (1, 2): 1.6698255595592497,
+        (1, 3): 1.099139603924817,
+        (1, 4): 1.3529705111901453,
+        (1, 5): 1.467907742900842,
+        (1, 6): 1.5346837414708774,
+        (2, 1): 1.9783090609123972,
+        (2, 2): 1.130315350158659,
+        (2, 3): 1.6712434682302661,
+        (2, 4): 1.3642294159473756,
+        (2, 5): 1.4888357071619858,
+        (2, 6): 1.2030122107340537,
+        (3, 1): 1.6661983755713592,
+        (3, 2): 1.227663031206932,
+        (3, 3): 1.4580640582967632,
+        (3, 4): 1.0407223975549575,
+        (3, 5): 1.9742897953778287,
+        (3, 6): 1.4874760742689066,
+        (4, 1): 1.4616138636373597,
+        (4, 2): 1.7141471558082002,
+        (4, 3): 1.4157281494999725,
+        (4, 4): 1.888011688001529,
+        (4, 5): 1.0232934487237717,
+        (4, 6): 1.8335062677845464,
+        (5, 1): 1.468494740997508,
+        (5, 2): 1.8114798126442795,
+        (5, 3): 1.9455914886158723,
+        (5, 4): 1.983088378194899,
+        (5, 5): 1.1761820755785306,
+        (5, 6): 1.698655759576308,
+        (6, 1): 1.108855711312383,
+        (6, 2): 1.1602637342062019,
+        (6, 3): 1.0928602740245892,
+        (6, 4): 1.3140620798928404,
+        (6, 5): 1.0165386843386672,
+        (6, 6): 1.854049125736362,
+        (7, 1): 1.2910160386456968,
+        (7, 2): 1.7800475863350327,
+        (7, 3): 1.5480965161255695,
+        (7, 4): 1.1943306766997612,
+        (7, 5): 1.2920382721805297,
+        (7, 6): 1.3194527773994338,
+        (8, 1): 1.6585982235379078,
+        (8, 2): 1.2315210354122292,
+        (8, 3): 1.6194303369953538,
+        (8, 4): 1.8953386098022103,
+        (8, 5): 1.8694342085696831,
+        (8, 6): 1.2938069356684523,
+        (9, 1): 1.4582048085805495,
+        (9, 2): 1.484979797871119,
+        (9, 3): 1.2803882693587225,
+        (9, 4): 1.3289569463506004,
+        (9, 5): 1.9842424240265042,
+        (9, 6): 1.0119441379208745,
+        (10, 1): 1.1429007682932852,
+        (10, 2): 1.6519772165446711,
+        (10, 3): 1.0749931799469326,
+        (10, 4): 1.2920787022811089,
+        (10, 5): 1.7934429721917704,
+        (10, 6): 1.9115931008709737,
+    }
+
+    model = pe.ConcreteModel()
+    model.N = pe.Param(initialize=10)
+    model.Locations = pe.RangeSet(1, model.N)
+    model.P = pe.Param(initialize=3)
+    model.M = pe.Param(initialize=6)
+    model.Customers = pe.RangeSet(1, model.M)
+    model.d = pe.Param(
+        model.Locations, model.Customers, initialize=d_dict, within=pe.Reals
+    )
+    model.x = pe.Var(model.Locations, model.Customers, bounds=(0.0, 1.0))
+    model.y = pe.Var(model.Locations, within=pe.Binary)
+
+    def rule(model):
+        return sum(
+            model.d[n, m] * model.x[n, m]
+            for n in model.Locations
+            for m in model.Customers
+        )
+
+    model.obj = pe.Objective(rule=rule)
+
+    def rule(model, m):
+        return (sum(model.x[n, m] for n in model.Locations), 1.0)
+
+    model.single_x = pe.Constraint(model.Customers, rule=rule)
+
+    def rule(model, n, m):
+        return (None, model.x[n, m] - model.y[n], 0.0)
+
+    model.bound_y = pe.Constraint(model.Locations, model.Customers, rule=rule)
+
+    def rule(model):
+        return (sum(model.y[n] for n in model.Locations) - model.P, 0.0)
+
+    model.num_facilities = pe.Constraint(rule=rule)
+
+    return model
+
+
+class TestGurobiPersistentSimpleLPUpdates(unittest.TestCase):
+    def setUp(self):
+        self.m = pe.ConcreteModel()
+        m = self.m
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.p1 = pe.Param(mutable=True)
+        m.p2 = pe.Param(mutable=True)
+        m.p3 = pe.Param(mutable=True)
+        m.p4 = pe.Param(mutable=True)
+        m.obj = pe.Objective(expr=m.x + m.y)
+        m.c1 = pe.Constraint(expr=m.y - m.p1 * m.x >= m.p2)
+        m.c2 = pe.Constraint(expr=m.y - m.p3 * m.x >= m.p4)
+
+    def get_solution(self):
+        try:
+            import numpy as np
+        except:
+            raise unittest.SkipTest('numpy is not available')
+        p1 = self.m.p1.value
+        p2 = self.m.p2.value
+        p3 = self.m.p3.value
+        p4 = self.m.p4.value
+        A = np.array([[1, -p1], [1, -p3]])
+        rhs = np.array([p2, p4])
+        sol = np.linalg.solve(A, rhs)
+        x = float(sol[1])
+        y = float(sol[0])
+        return x, y
+
+    def set_params(self, p1, p2, p3, p4):
+        self.m.p1.value = p1
+        self.m.p2.value = p2
+        self.m.p3.value = p3
+        self.m.p4.value = p4
+
+    def test_lp(self):
+        self.set_params(-1, -2, 0.1, -2)
+        x, y = self.get_solution()
+        opt = Gurobi()
+        res = opt.solve(self.m)
+        self.assertAlmostEqual(x + y, res.incumbent_objective)
+        self.assertAlmostEqual(x + y, res.objective_bound)
+        self.assertEqual(res.solution_status, SolutionStatus.optimal)
+        self.assertTrue(res.incumbent_objective is not None)
+        self.assertAlmostEqual(x, self.m.x.value)
+        self.assertAlmostEqual(y, self.m.y.value)
+
+        self.set_params(-1.25, -1, 0.5, -2)
+        opt.config.load_solutions = False
+        res = opt.solve(self.m)
+        self.assertAlmostEqual(x, self.m.x.value)
+        self.assertAlmostEqual(y, self.m.y.value)
+        x, y = self.get_solution()
+        self.assertNotAlmostEqual(x, self.m.x.value)
+        self.assertNotAlmostEqual(y, self.m.y.value)
+        res.solution_loader.load_vars()
+        self.assertAlmostEqual(x, self.m.x.value)
+        self.assertAlmostEqual(y, self.m.y.value)
+
+
+class TestGurobiPersistent(unittest.TestCase):
+    def test_nonconvex_qcp_objective_bound_1(self):
+        # the goal of this test is to ensure we can get an objective bound
+        # for nonconvex but continuous problems even if a feasible solution
+        # is not found
+        #
+        # This is a fragile test because it could fail if Gurobi's algorithms improve
+        # (e.g., a heuristic solution is found before an objective bound of -8 is reached
+        m = pe.ConcreteModel()
+        m.x = pe.Var(bounds=(-5, 5))
+        m.y = pe.Var(bounds=(-5, 5))
+        m.obj = pe.Objective(expr=-m.x**2 - m.y)
+        m.c1 = pe.Constraint(expr=m.y <= -2 * m.x + 1)
+        m.c2 = pe.Constraint(expr=m.y <= m.x - 2)
+        opt = Gurobi()
+        opt.config.solver_options['nonconvex'] = 2
+        opt.config.solver_options['BestBdStop'] = -8
+        opt.config.load_solutions = False
+        opt.config.raise_exception_on_nonoptimal_result = False
+        res = opt.solve(m)
+        self.assertEqual(res.incumbent_objective, None)
+        self.assertAlmostEqual(res.objective_bound, -8)
+
+    def test_nonconvex_qcp_objective_bound_2(self):
+        # the goal of this test is to ensure we can objective_bound properly
+        # for nonconvex but continuous problems when the solver terminates with a nonzero gap
+        #
+        # This is a fragile test because it could fail if Gurobi's algorithms change
+        m = pe.ConcreteModel()
+        m.x = pe.Var(bounds=(-5, 5))
+        m.y = pe.Var(bounds=(-5, 5))
+        m.obj = pe.Objective(expr=-m.x**2 - m.y)
+        m.c1 = pe.Constraint(expr=m.y <= -2 * m.x + 1)
+        m.c2 = pe.Constraint(expr=m.y <= m.x - 2)
+        opt = Gurobi()
+        opt.config.solver_options['nonconvex'] = 2
+        opt.config.solver_options['MIPGap'] = 0.5
+        res = opt.solve(m)
+        self.assertAlmostEqual(res.incumbent_objective, -4)
+        self.assertAlmostEqual(res.objective_bound, -6)
+
+    def test_range_constraints(self):
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.xl = pe.Param(initialize=-1, mutable=True)
+        m.xu = pe.Param(initialize=1, mutable=True)
+        m.c = pe.Constraint(expr=pe.inequality(m.xl, m.x, m.xu))
+        m.obj = pe.Objective(expr=m.x)
+
+        opt = Gurobi()
+        opt.set_instance(m)
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.x.value, -1)
+
+        m.xl.value = -3
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.x.value, -3)
+
+        del m.obj
+        m.obj = pe.Objective(expr=m.x, sense=pe.maximize)
+
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.x.value, 1)
+
+        m.xu.value = 3
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.x.value, 3)
+
+    def test_quadratic_constraint_with_params(self):
+        m = pe.ConcreteModel()
+        m.a = pe.Param(initialize=1, mutable=True)
+        m.b = pe.Param(initialize=1, mutable=True)
+        m.c = pe.Param(initialize=1, mutable=True)
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.obj = pe.Objective(expr=m.y)
+        m.con = pe.Constraint(expr=m.y >= m.a * m.x**2 + m.b * m.x + m.c)
+
+        opt = Gurobi()
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.x.value, -m.b.value / (2 * m.a.value))
+        self.assertAlmostEqual(
+            m.y.value, m.a.value * m.x.value**2 + m.b.value * m.x.value + m.c.value
+        )
+
+        m.a.value = 2
+        m.b.value = 4
+        m.c.value = -1
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.x.value, -m.b.value / (2 * m.a.value))
+        self.assertAlmostEqual(
+            m.y.value, m.a.value * m.x.value**2 + m.b.value * m.x.value + m.c.value
+        )
+
+    def test_quadratic_objective(self):
+        m = pe.ConcreteModel()
+        m.a = pe.Param(initialize=1, mutable=True)
+        m.b = pe.Param(initialize=1, mutable=True)
+        m.c = pe.Param(initialize=1, mutable=True)
+        m.x = pe.Var()
+        m.obj = pe.Objective(expr=m.a * m.x**2 + m.b * m.x + m.c)
+
+        opt = Gurobi()
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.x.value, -m.b.value / (2 * m.a.value))
+        self.assertAlmostEqual(
+            res.incumbent_objective,
+            m.a.value * m.x.value**2 + m.b.value * m.x.value + m.c.value,
+        )
+
+        m.a.value = 2
+        m.b.value = 4
+        m.c.value = -1
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.x.value, -m.b.value / (2 * m.a.value))
+        self.assertAlmostEqual(
+            res.incumbent_objective,
+            m.a.value * m.x.value**2 + m.b.value * m.x.value + m.c.value,
+        )
+
+    def test_var_bounds(self):
+        m = pe.ConcreteModel()
+        m.x = pe.Var(bounds=(-1, 1))
+        m.obj = pe.Objective(expr=m.x)
+
+        opt = Gurobi()
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.x.value, -1)
+
+        m.x.setlb(-3)
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.x.value, -3)
+
+        del m.obj
+        m.obj = pe.Objective(expr=m.x, sense=pe.maximize)
+
+        opt = Gurobi()
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.x.value, 1)
+
+        m.x.setub(3)
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.x.value, 3)
+
+    def test_fixed_var(self):
+        m = pe.ConcreteModel()
+        m.a = pe.Param(initialize=1, mutable=True)
+        m.b = pe.Param(initialize=1, mutable=True)
+        m.c = pe.Param(initialize=1, mutable=True)
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.obj = pe.Objective(expr=m.y)
+        m.con = pe.Constraint(expr=m.y >= m.a * m.x**2 + m.b * m.x + m.c)
+
+        m.x.fix(1)
+        opt = Gurobi()
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.x.value, 1)
+        self.assertAlmostEqual(m.y.value, 3)
+
+        m.x.value = 2
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.x.value, 2)
+        self.assertAlmostEqual(m.y.value, 7)
+
+        m.x.unfix()
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.x.value, -m.b.value / (2 * m.a.value))
+        self.assertAlmostEqual(
+            m.y.value, m.a.value * m.x.value**2 + m.b.value * m.x.value + m.c.value
+        )
+
+    def test_linear_constraint_attr(self):
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.c = pe.Constraint(expr=m.x + m.y == 1)
+
+        opt = Gurobi()
+        opt.set_instance(m)
+        opt.set_linear_constraint_attr(m.c, 'Lazy', 1)
+        self.assertEqual(opt.get_linear_constraint_attr(m.c, 'Lazy'), 1)
+
+    def test_quadratic_constraint_attr(self):
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.c = pe.Constraint(expr=m.y >= m.x**2)
+
+        opt = Gurobi()
+        opt.set_instance(m)
+        self.assertEqual(opt.get_quadratic_constraint_attr(m.c, 'QCRHS'), 0)
+
+    def test_var_attr(self):
+        m = pe.ConcreteModel()
+        m.x = pe.Var(within=pe.Binary)
+        m.obj = pe.Objective(expr=m.x)
+
+        opt = Gurobi()
+        opt.set_instance(m)
+        opt.set_var_attr(m.x, 'Start', 1)
+        self.assertEqual(opt.get_var_attr(m.x, 'Start'), 1)
+
+    def test_callback(self):
+        m = pe.ConcreteModel()
+        m.x = pe.Var(bounds=(0, 4))
+        m.y = pe.Var(within=pe.Integers, bounds=(0, None))
+        m.obj = pe.Objective(expr=2 * m.x + m.y)
+        m.cons = pe.ConstraintList()
+
+        def _add_cut(xval):
+            m.x.value = xval
+            return m.cons.add(m.y >= taylor_series_expansion((m.x - 2) ** 2))
+
+        _add_cut(0)
+        _add_cut(4)
+
+        opt = Gurobi()
+        opt.set_instance(m)
+        opt.set_gurobi_param('PreCrush', 1)
+        opt.set_gurobi_param('LazyConstraints', 1)
+
+        def _my_callback(cb_m, cb_opt, cb_where):
+            if cb_where == gurobipy.GRB.Callback.MIPSOL:
+                cb_opt.cbGetSolution(vars=[m.x, m.y])
+                if m.y.value < (m.x.value - 2) ** 2 - 1e-6:
+                    cb_opt.cbLazy(_add_cut(m.x.value))
+
+        opt.set_callback(_my_callback)
+        opt.solve(m)
+        self.assertAlmostEqual(m.x.value, 1)
+        self.assertAlmostEqual(m.y.value, 1)
+
+    def test_nonconvex(self):
+        if gurobipy.GRB.VERSION_MAJOR < 9:
+            raise unittest.SkipTest
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.obj = pe.Objective(expr=m.x**2 + m.y**2)
+        m.c = pe.Constraint(expr=m.y == (m.x - 1) ** 2 - 2)
+        opt = Gurobi()
+        opt.config.solver_options['nonconvex'] = 2
+        opt.solve(m)
+        self.assertAlmostEqual(m.x.value, -0.3660254037844423, 2)
+        self.assertAlmostEqual(m.y.value, -0.13397459621555508, 2)
+
+    def test_nonconvex2(self):
+        if gurobipy.GRB.VERSION_MAJOR < 9:
+            raise unittest.SkipTest
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.obj = pe.Objective(expr=m.x**2 + m.y**2)
+        m.c1 = pe.Constraint(expr=0 <= -m.y + (m.x - 1) ** 2 - 2)
+        m.c2 = pe.Constraint(expr=0 >= -m.y + (m.x - 1) ** 2 - 2)
+        opt = Gurobi()
+        opt.config.solver_options['nonconvex'] = 2
+        opt.solve(m)
+        self.assertAlmostEqual(m.x.value, -0.3660254037844423, 2)
+        self.assertAlmostEqual(m.y.value, -0.13397459621555508, 2)
+
+    def test_solution_number(self):
+        m = create_pmedian_model()
+        opt = Gurobi()
+        opt.config.solver_options['PoolSolutions'] = 3
+        opt.config.solver_options['PoolSearchMode'] = 2
+        res = opt.solve(m)
+        num_solutions = opt.get_model_attr('SolCount')
+        self.assertEqual(num_solutions, 3)
+        res.solution_loader.load_vars(solution_number=0)
+        self.assertAlmostEqual(pe.value(m.obj.expr), 6.431184939357673)
+        res.solution_loader.load_vars(solution_number=1)
+        self.assertAlmostEqual(pe.value(m.obj.expr), 6.584793218502477)
+        res.solution_loader.load_vars(solution_number=2)
+        self.assertAlmostEqual(pe.value(m.obj.expr), 6.592304628123309)
+
+    def test_zero_time_limit(self):
+        m = create_pmedian_model()
+        opt = Gurobi()
+        opt.config.time_limit = 0
+        opt.config.load_solutions = False
+        opt.config.raise_exception_on_nonoptimal_result = False
+        res = opt.solve(m)
+        num_solutions = opt.get_model_attr('SolCount')
+
+        # Behavior is different on different platforms, so
+        # we have to see if there are any solutions
+        # This means that there is no guarantee we are testing
+        # what we are trying to test. Unfortunately, I'm
+        # not sure of a good way to guarantee that
+        if num_solutions == 0:
+            self.assertIsNone(res.incumbent_objective)
+
+
+class TestManualModel(unittest.TestCase):
+    def setUp(self):
+        opt = Gurobi()
+        opt.config.auto_updates.check_for_new_or_removed_params = False
+        opt.config.auto_updates.check_for_new_or_removed_vars = False
+        opt.config.auto_updates.check_for_new_or_removed_constraints = False
+        opt.config.auto_updates.update_parameters = False
+        opt.config.auto_updates.update_vars = False
+        opt.config.auto_updates.update_constraints = False
+        opt.config.auto_updates.update_named_expressions = False
+        self.opt = opt
+
+    def test_basics(self):
+        m = pe.ConcreteModel()
+        m.x = pe.Var(bounds=(-10, 10))
+        m.y = pe.Var()
+        m.obj = pe.Objective(expr=m.x**2 + m.y**2)
+        m.c1 = pe.Constraint(expr=m.y >= 2 * m.x + 1)
+
+        opt = self.opt
+        opt.set_instance(m)
+
+        self.assertEqual(opt.get_model_attr('NumVars'), 2)
+        self.assertEqual(opt.get_model_attr('NumConstrs'), 1)
+        self.assertEqual(opt.get_model_attr('NumQConstrs'), 0)
+        self.assertEqual(opt.get_var_attr(m.x, 'LB'), -10)
+        self.assertEqual(opt.get_var_attr(m.x, 'UB'), 10)
+
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.x.value, -0.4)
+        self.assertAlmostEqual(m.y.value, 0.2)
+        duals = res.solution_loader.get_duals()
+        self.assertAlmostEqual(duals[m.c1], -0.4)
+
+        m.c2 = pe.Constraint(expr=m.y >= -m.x + 1)
+        opt.add_constraints([m.c2])
+        self.assertEqual(opt.get_model_attr('NumVars'), 2)
+        self.assertEqual(opt.get_model_attr('NumConstrs'), 2)
+        self.assertEqual(opt.get_model_attr('NumQConstrs'), 0)
+
+        opt.config.load_solutions = False
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.x.value, -0.4)
+        self.assertAlmostEqual(m.y.value, 0.2)
+        res.solution_loader.load_vars()
+        self.assertAlmostEqual(m.x.value, 0)
+        self.assertAlmostEqual(m.y.value, 1)
+
+        opt.remove_constraints([m.c2])
+        m.del_component(m.c2)
+        self.assertEqual(opt.get_model_attr('NumVars'), 2)
+        self.assertEqual(opt.get_model_attr('NumConstrs'), 1)
+        self.assertEqual(opt.get_model_attr('NumQConstrs'), 0)
+
+        self.assertEqual(opt.get_gurobi_param_info('FeasibilityTol')[2], 1e-6)
+        opt.config.solver_options['FeasibilityTol'] = 1e-7
+        opt.config.load_solutions = True
+        res = opt.solve(m)
+        self.assertEqual(opt.get_gurobi_param_info('FeasibilityTol')[2], 1e-7)
+        self.assertAlmostEqual(m.x.value, -0.4)
+        self.assertAlmostEqual(m.y.value, 0.2)
+
+        m.x.setlb(-5)
+        m.x.setub(5)
+        opt.update_variables([m.x])
+        self.assertEqual(opt.get_var_attr(m.x, 'LB'), -5)
+        self.assertEqual(opt.get_var_attr(m.x, 'UB'), 5)
+
+        m.x.fix(0)
+        opt.update_variables([m.x])
+        self.assertEqual(opt.get_var_attr(m.x, 'LB'), 0)
+        self.assertEqual(opt.get_var_attr(m.x, 'UB'), 0)
+
+        m.x.unfix()
+        opt.update_variables([m.x])
+        self.assertEqual(opt.get_var_attr(m.x, 'LB'), -5)
+        self.assertEqual(opt.get_var_attr(m.x, 'UB'), 5)
+
+        m.c2 = pe.Constraint(expr=m.y >= m.x**2)
+        opt.add_constraints([m.c2])
+        self.assertEqual(opt.get_model_attr('NumVars'), 2)
+        self.assertEqual(opt.get_model_attr('NumConstrs'), 1)
+        self.assertEqual(opt.get_model_attr('NumQConstrs'), 1)
+
+        opt.remove_constraints([m.c2])
+        m.del_component(m.c2)
+        self.assertEqual(opt.get_model_attr('NumVars'), 2)
+        self.assertEqual(opt.get_model_attr('NumConstrs'), 1)
+        self.assertEqual(opt.get_model_attr('NumQConstrs'), 0)
+
+        m.z = pe.Var()
+        opt.add_variables([m.z])
+        self.assertEqual(opt.get_model_attr('NumVars'), 3)
+        opt.remove_variables([m.z])
+        del m.z
+        self.assertEqual(opt.get_model_attr('NumVars'), 2)
+
+    def test_update1(self):
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.z = pe.Var()
+        m.obj = pe.Objective(expr=m.z)
+        m.c1 = pe.Constraint(expr=m.z >= m.x**2 + m.y**2)
+
+        opt = self.opt
+        opt.set_instance(m)
+        self.assertEqual(opt._solver_model.getAttr('NumQConstrs'), 1)
+
+        opt.remove_constraints([m.c1])
+        opt.update()
+        self.assertEqual(opt._solver_model.getAttr('NumQConstrs'), 0)
+
+        opt.add_constraints([m.c1])
+        self.assertEqual(opt._solver_model.getAttr('NumQConstrs'), 0)
+        opt.update()
+        self.assertEqual(opt._solver_model.getAttr('NumQConstrs'), 1)
+
+    def test_update2(self):
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.z = pe.Var()
+        m.obj = pe.Objective(expr=m.z)
+        m.c2 = pe.Constraint(expr=m.x + m.y == 1)
+
+        opt = self.opt
+        opt.config.symbolic_solver_labels = True
+        opt.set_instance(m)
+        self.assertEqual(opt._solver_model.getAttr('NumConstrs'), 1)
+
+        opt.remove_constraints([m.c2])
+        opt.update()
+        self.assertEqual(opt._solver_model.getAttr('NumConstrs'), 0)
+
+        opt.add_constraints([m.c2])
+        self.assertEqual(opt._solver_model.getAttr('NumConstrs'), 0)
+        opt.update()
+        self.assertEqual(opt._solver_model.getAttr('NumConstrs'), 1)
+
+    def test_update3(self):
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.z = pe.Var()
+        m.obj = pe.Objective(expr=m.z)
+        m.c1 = pe.Constraint(expr=m.z >= m.x**2 + m.y**2)
+
+        opt = self.opt
+        opt.set_instance(m)
+        opt.update()
+        self.assertEqual(opt._solver_model.getAttr('NumQConstrs'), 1)
+        m.c2 = pe.Constraint(expr=m.y >= m.x**2)
+        opt.add_constraints([m.c2])
+        self.assertEqual(opt._solver_model.getAttr('NumQConstrs'), 1)
+        opt.remove_constraints([m.c2])
+        opt.update()
+        self.assertEqual(opt._solver_model.getAttr('NumQConstrs'), 1)
+
+    def test_update4(self):
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.z = pe.Var()
+        m.obj = pe.Objective(expr=m.z)
+        m.c1 = pe.Constraint(expr=m.z >= m.x + m.y)
+
+        opt = self.opt
+        opt.set_instance(m)
+        opt.update()
+        self.assertEqual(opt._solver_model.getAttr('NumConstrs'), 1)
+        m.c2 = pe.Constraint(expr=m.y >= m.x)
+        opt.add_constraints([m.c2])
+        self.assertEqual(opt._solver_model.getAttr('NumConstrs'), 1)
+        opt.remove_constraints([m.c2])
+        opt.update()
+        self.assertEqual(opt._solver_model.getAttr('NumConstrs'), 1)
+
+    def test_update5(self):
+        m = pe.ConcreteModel()
+        m.a = pe.Set(initialize=[1, 2, 3], ordered=True)
+        m.x = pe.Var(m.a, within=pe.Binary)
+        m.y = pe.Var(within=pe.Binary)
+        m.obj = pe.Objective(expr=m.y)
+        m.c1 = pe.SOSConstraint(var=m.x, sos=1)
+
+        opt = self.opt
+        opt.set_instance(m)
+        self.assertEqual(opt._solver_model.getAttr('NumSOS'), 1)
+
+        opt.remove_sos_constraints([m.c1])
+        opt.update()
+        self.assertEqual(opt._solver_model.getAttr('NumSOS'), 0)
+
+        opt.add_sos_constraints([m.c1])
+        self.assertEqual(opt._solver_model.getAttr('NumSOS'), 0)
+        opt.update()
+        self.assertEqual(opt._solver_model.getAttr('NumSOS'), 1)
+
+    def test_update6(self):
+        m = pe.ConcreteModel()
+        m.a = pe.Set(initialize=[1, 2, 3], ordered=True)
+        m.x = pe.Var(m.a, within=pe.Binary)
+        m.y = pe.Var(within=pe.Binary)
+        m.obj = pe.Objective(expr=m.y)
+        m.c1 = pe.SOSConstraint(var=m.x, sos=1)
+
+        opt = self.opt
+        opt.set_instance(m)
+        opt.update()
+        self.assertEqual(opt._solver_model.getAttr('NumSOS'), 1)
+        m.c2 = pe.SOSConstraint(var=m.x, sos=2)
+        opt.add_sos_constraints([m.c2])
+        self.assertEqual(opt._solver_model.getAttr('NumSOS'), 1)
+        opt.remove_sos_constraints([m.c2])
+        opt.update()
+        self.assertEqual(opt._solver_model.getAttr('NumSOS'), 1)
diff --git a/pyomo/contrib/solver/tests/solvers/test_ipopt.py b/pyomo/contrib/solver/tests/solvers/test_ipopt.py
new file mode 100644
index 00000000000..d5d82981ed8
--- /dev/null
+++ b/pyomo/contrib/solver/tests/solvers/test_ipopt.py
@@ -0,0 +1,57 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+
+import pyomo.environ as pyo
+from pyomo.common.fileutils import ExecutableData
+from pyomo.common.config import ConfigDict
+from pyomo.contrib.solver.ipopt import IpoptConfig
+from pyomo.contrib.solver.factory import SolverFactory
+from pyomo.common import unittest
+
+
+"""
+TODO:
+    - Test unique configuration options
+    - Test unique results options
+    - Ensure that `*.opt` file is only created when needed
+    - Ensure options are correctly parsing to env or opt file
+    - Failures at appropriate times
+"""
+
+
+class TestIpopt(unittest.TestCase):
+    def create_model(self):
+        model = pyo.ConcreteModel()
+        model.x = pyo.Var(initialize=1.5)
+        model.y = pyo.Var(initialize=1.5)
+
+        def rosenbrock(m):
+            return (1.0 - m.x) ** 2 + 100.0 * (m.y - m.x**2) ** 2
+
+        model.obj = pyo.Objective(rule=rosenbrock, sense=pyo.minimize)
+        return model
+
+    def test_ipopt_config(self):
+        # Test default initialization
+        config = IpoptConfig()
+        self.assertTrue(config.load_solutions)
+        self.assertIsInstance(config.solver_options, ConfigDict)
+        self.assertIsInstance(config.executable, ExecutableData)
+
+        # Test custom initialization
+        solver = SolverFactory('ipopt', executable='/path/to/exe')
+        self.assertFalse(solver.config.tee)
+        self.assertTrue(solver.config.executable.startswith('/path'))
+
+        # Change value on a solve call
+        # model = self.create_model()
+        # result = solver.solve(model, tee=True)
diff --git a/pyomo/contrib/solver/tests/solvers/test_solvers.py b/pyomo/contrib/solver/tests/solvers/test_solvers.py
new file mode 100644
index 00000000000..f91de2287b7
--- /dev/null
+++ b/pyomo/contrib/solver/tests/solvers/test_solvers.py
@@ -0,0 +1,1682 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import random
+import math
+from typing import Type
+
+import pyomo.environ as pe
+from pyomo import gdp
+from pyomo.common.dependencies import attempt_import
+import pyomo.common.unittest as unittest
+from pyomo.contrib.solver.results import TerminationCondition, SolutionStatus, Results
+from pyomo.contrib.solver.base import SolverBase
+from pyomo.contrib.solver.ipopt import Ipopt
+from pyomo.contrib.solver.gurobi import Gurobi
+from pyomo.contrib.solver.gurobi_direct import GurobiDirect
+from pyomo.core.expr.numeric_expr import LinearExpression
+
+
+np, numpy_available = attempt_import('numpy')
+parameterized, param_available = attempt_import('parameterized')
+parameterized = parameterized.parameterized
+
+
+if not param_available:
+    raise unittest.SkipTest('Parameterized is not available.')
+
+all_solvers = [('gurobi', Gurobi), ('gurobi_direct', GurobiDirect), ('ipopt', Ipopt)]
+mip_solvers = [('gurobi', Gurobi), ('gurobi_direct', GurobiDirect)]
+nlp_solvers = [('ipopt', Ipopt)]
+qcp_solvers = [('gurobi', Gurobi), ('ipopt', Ipopt)]
+miqcqp_solvers = [('gurobi', Gurobi)]
+nl_solvers = [('ipopt', Ipopt)]
+nl_solvers_set = {i[0] for i in nl_solvers}
+
+
+def _load_tests(solver_list):
+    res = list()
+    for solver_name, solver in solver_list:
+        if solver_name in nl_solvers_set:
+            test_name = f"{solver_name}_presolve"
+            res.append((test_name, solver, True))
+            test_name = f"{solver_name}"
+            res.append((test_name, solver, False))
+        else:
+            test_name = f"{solver_name}"
+            res.append((test_name, solver, None))
+    return res
+
+
+@unittest.skipUnless(numpy_available, 'numpy is not available')
+class TestSolvers(unittest.TestCase):
+    @parameterized.expand(input=all_solvers)
+    def test_config_overwrite(self, name: str, opt_class: Type[SolverBase]):
+        self.assertIsNot(SolverBase.CONFIG, opt_class.CONFIG)
+
+    @parameterized.expand(input=_load_tests(all_solvers))
+    def test_remove_variable_and_objective(
+        self, name: str, opt_class: Type[SolverBase], use_presolve
+    ):
+        # this test is for issue #2888
+        opt: SolverBase = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+        m = pe.ConcreteModel()
+        m.x = pe.Var(bounds=(2, None))
+        m.obj = pe.Objective(expr=m.x)
+        res = opt.solve(m)
+        self.assertEqual(res.solution_status, SolutionStatus.optimal)
+        self.assertAlmostEqual(m.x.value, 2)
+
+        del m.x
+        del m.obj
+        m.x = pe.Var(bounds=(2, None))
+        m.obj = pe.Objective(expr=m.x)
+        res = opt.solve(m)
+        self.assertEqual(res.solution_status, SolutionStatus.optimal)
+        self.assertAlmostEqual(m.x.value, 2)
+
+    @parameterized.expand(input=_load_tests(all_solvers))
+    def test_stale_vars(
+        self, name: str, opt_class: Type[SolverBase], use_presolve: bool
+    ):
+        opt: SolverBase = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.z = pe.Var()
+        m.obj = pe.Objective(expr=m.y)
+        m.c1 = pe.Constraint(expr=m.y >= m.x)
+        m.c2 = pe.Constraint(expr=m.y >= -m.x)
+        m.x.value = 1
+        m.y.value = 1
+        m.z.value = 1
+        self.assertFalse(m.x.stale)
+        self.assertFalse(m.y.stale)
+        self.assertFalse(m.z.stale)
+
+        res = opt.solve(m)
+        self.assertFalse(m.x.stale)
+        self.assertFalse(m.y.stale)
+        self.assertTrue(m.z.stale)
+
+        opt.config.load_solutions = False
+        res = opt.solve(m)
+        self.assertTrue(m.x.stale)
+        self.assertTrue(m.y.stale)
+        self.assertTrue(m.z.stale)
+        res.solution_loader.load_vars()
+        self.assertFalse(m.x.stale)
+        self.assertFalse(m.y.stale)
+        self.assertTrue(m.z.stale)
+
+        res = opt.solve(m)
+        self.assertTrue(m.x.stale)
+        self.assertTrue(m.y.stale)
+        self.assertTrue(m.z.stale)
+        res.solution_loader.load_vars([m.y])
+        self.assertFalse(m.y.stale)
+
+    @parameterized.expand(input=_load_tests(all_solvers))
+    def test_range_constraint(
+        self, name: str, opt_class: Type[SolverBase], use_presolve: bool
+    ):
+        opt: SolverBase = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.obj = pe.Objective(expr=m.x)
+        m.c = pe.Constraint(expr=(-1, m.x, 1))
+        res = opt.solve(m)
+        self.assertEqual(res.solution_status, SolutionStatus.optimal)
+        self.assertAlmostEqual(m.x.value, -1)
+        duals = res.solution_loader.get_duals()
+        self.assertAlmostEqual(duals[m.c], 1)
+        m.obj.sense = pe.maximize
+        res = opt.solve(m)
+        self.assertEqual(res.solution_status, SolutionStatus.optimal)
+        self.assertAlmostEqual(m.x.value, 1)
+        duals = res.solution_loader.get_duals()
+        self.assertAlmostEqual(duals[m.c], 1)
+
+    @parameterized.expand(input=_load_tests(all_solvers))
+    def test_reduced_costs(
+        self, name: str, opt_class: Type[SolverBase], use_presolve: bool
+    ):
+        opt: SolverBase = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+        m = pe.ConcreteModel()
+        m.x = pe.Var(bounds=(-1, 1))
+        m.y = pe.Var(bounds=(-2, 2))
+        m.obj = pe.Objective(expr=3 * m.x + 4 * m.y)
+        res = opt.solve(m)
+        self.assertEqual(res.solution_status, SolutionStatus.optimal)
+        self.assertAlmostEqual(m.x.value, -1)
+        self.assertAlmostEqual(m.y.value, -2)
+        rc = res.solution_loader.get_reduced_costs()
+        self.assertAlmostEqual(rc[m.x], 3)
+        self.assertAlmostEqual(rc[m.y], 4)
+        m.obj.expr *= -1
+        res = opt.solve(m)
+        rc = res.solution_loader.get_reduced_costs()
+        self.assertAlmostEqual(rc[m.x], -3)
+        self.assertAlmostEqual(rc[m.y], -4)
+
+    @parameterized.expand(input=_load_tests(all_solvers))
+    def test_reduced_costs2(
+        self, name: str, opt_class: Type[SolverBase], use_presolve: bool
+    ):
+        opt: SolverBase = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+        m = pe.ConcreteModel()
+        m.x = pe.Var(bounds=(-1, 1))
+        m.obj = pe.Objective(expr=m.x)
+        res = opt.solve(m)
+        self.assertEqual(res.solution_status, SolutionStatus.optimal)
+        self.assertAlmostEqual(m.x.value, -1)
+        rc = res.solution_loader.get_reduced_costs()
+        self.assertAlmostEqual(rc[m.x], 1)
+        m.obj.sense = pe.maximize
+        res = opt.solve(m)
+        self.assertEqual(res.solution_status, SolutionStatus.optimal)
+        self.assertAlmostEqual(m.x.value, 1)
+        rc = res.solution_loader.get_reduced_costs()
+        self.assertAlmostEqual(rc[m.x], 1)
+
+    @parameterized.expand(input=_load_tests(all_solvers))
+    def test_param_changes(
+        self, name: str, opt_class: Type[SolverBase], use_presolve: bool
+    ):
+        opt: SolverBase = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.a1 = pe.Param(mutable=True)
+        m.a2 = pe.Param(mutable=True)
+        m.b1 = pe.Param(mutable=True)
+        m.b2 = pe.Param(mutable=True)
+        m.obj = pe.Objective(expr=m.y)
+        m.c1 = pe.Constraint(expr=(0, m.y - m.a1 * m.x - m.b1, None))
+        m.c2 = pe.Constraint(expr=(None, -m.y + m.a2 * m.x + m.b2, 0))
+
+        params_to_test = [(1, -1, 2, 1), (1, -2, 2, 1), (1, -1, 3, 1)]
+        for a1, a2, b1, b2 in params_to_test:
+            m.a1.value = a1
+            m.a2.value = a2
+            m.b1.value = b1
+            m.b2.value = b2
+            res: Results = opt.solve(m)
+            self.assertEqual(res.solution_status, SolutionStatus.optimal)
+            self.assertAlmostEqual(m.x.value, (b2 - b1) / (a1 - a2))
+            self.assertAlmostEqual(m.y.value, a1 * (b2 - b1) / (a1 - a2) + b1)
+            self.assertAlmostEqual(res.incumbent_objective, m.y.value)
+            if res.objective_bound is None:
+                bound = -math.inf
+            else:
+                bound = res.objective_bound
+            self.assertTrue(bound <= m.y.value)
+            duals = res.solution_loader.get_duals()
+            self.assertAlmostEqual(duals[m.c1], (1 + a1 / (a2 - a1)))
+            self.assertAlmostEqual(duals[m.c2], a1 / (a2 - a1))
+
+    @parameterized.expand(input=_load_tests(all_solvers))
+    def test_immutable_param(
+        self, name: str, opt_class: Type[SolverBase], use_presolve: bool
+    ):
+        """
+        This test is important because component_data_objects returns immutable params as floats.
+        We want to make sure we process these correctly.
+        """
+        opt: SolverBase = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.a1 = pe.Param(mutable=True)
+        m.a2 = pe.Param(initialize=-1)
+        m.b1 = pe.Param(mutable=True)
+        m.b2 = pe.Param(mutable=True)
+        m.obj = pe.Objective(expr=m.y)
+        m.c1 = pe.Constraint(expr=(0, m.y - m.a1 * m.x - m.b1, None))
+        m.c2 = pe.Constraint(expr=(None, -m.y + m.a2 * m.x + m.b2, 0))
+
+        params_to_test = [(1, 2, 1), (1, 2, 1), (1, 3, 1)]
+        for a1, b1, b2 in params_to_test:
+            a2 = m.a2.value
+            m.a1.value = a1
+            m.b1.value = b1
+            m.b2.value = b2
+            res: Results = opt.solve(m)
+            self.assertEqual(res.solution_status, SolutionStatus.optimal)
+            self.assertAlmostEqual(m.x.value, (b2 - b1) / (a1 - a2))
+            self.assertAlmostEqual(m.y.value, a1 * (b2 - b1) / (a1 - a2) + b1)
+            self.assertAlmostEqual(res.incumbent_objective, m.y.value)
+            if res.objective_bound is None:
+                bound = -math.inf
+            else:
+                bound = res.objective_bound
+            self.assertTrue(bound <= m.y.value)
+            duals = res.solution_loader.get_duals()
+            self.assertAlmostEqual(duals[m.c1], (1 + a1 / (a2 - a1)))
+            self.assertAlmostEqual(duals[m.c2], a1 / (a2 - a1))
+
+    @parameterized.expand(input=_load_tests(all_solvers))
+    def test_equality(self, name: str, opt_class: Type[SolverBase], use_presolve: bool):
+        opt: SolverBase = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        check_duals = True
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+                check_duals = False
+            else:
+                opt.config.writer_config.linear_presolve = False
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.a1 = pe.Param(mutable=True)
+        m.a2 = pe.Param(mutable=True)
+        m.b1 = pe.Param(mutable=True)
+        m.b2 = pe.Param(mutable=True)
+        m.obj = pe.Objective(expr=m.y)
+        m.c1 = pe.Constraint(expr=m.y == m.a1 * m.x + m.b1)
+        m.c2 = pe.Constraint(expr=m.y == m.a2 * m.x + m.b2)
+
+        params_to_test = [(1, -1, 2, 1), (1, -2, 2, 1), (1, -1, 3, 1)]
+        for a1, a2, b1, b2 in params_to_test:
+            m.a1.value = a1
+            m.a2.value = a2
+            m.b1.value = b1
+            m.b2.value = b2
+            res: Results = opt.solve(m)
+            self.assertEqual(res.solution_status, SolutionStatus.optimal)
+            self.assertAlmostEqual(m.x.value, (b2 - b1) / (a1 - a2))
+            self.assertAlmostEqual(m.y.value, a1 * (b2 - b1) / (a1 - a2) + b1)
+            self.assertAlmostEqual(res.incumbent_objective, m.y.value)
+            if res.objective_bound is None:
+                bound = -math.inf
+            else:
+                bound = res.objective_bound
+            self.assertTrue(bound <= m.y.value)
+            if check_duals:
+                duals = res.solution_loader.get_duals()
+                self.assertAlmostEqual(duals[m.c1], (1 + a1 / (a2 - a1)))
+                self.assertAlmostEqual(duals[m.c2], -a1 / (a2 - a1))
+
+    @parameterized.expand(input=_load_tests(all_solvers))
+    def test_linear_expression(
+        self, name: str, opt_class: Type[SolverBase], use_presolve: bool
+    ):
+        opt: SolverBase = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.a1 = pe.Param(mutable=True)
+        m.a2 = pe.Param(mutable=True)
+        m.b1 = pe.Param(mutable=True)
+        m.b2 = pe.Param(mutable=True)
+        m.obj = pe.Objective(expr=m.y)
+        e = LinearExpression(
+            constant=m.b1, linear_coefs=[-1, m.a1], linear_vars=[m.y, m.x]
+        )
+        m.c1 = pe.Constraint(expr=e == 0)
+        e = LinearExpression(
+            constant=m.b2, linear_coefs=[-1, m.a2], linear_vars=[m.y, m.x]
+        )
+        m.c2 = pe.Constraint(expr=e == 0)
+
+        params_to_test = [(1, -1, 2, 1), (1, -2, 2, 1), (1, -1, 3, 1)]
+        for a1, a2, b1, b2 in params_to_test:
+            m.a1.value = a1
+            m.a2.value = a2
+            m.b1.value = b1
+            m.b2.value = b2
+            res: Results = opt.solve(m)
+            self.assertEqual(res.solution_status, SolutionStatus.optimal)
+            self.assertAlmostEqual(m.y.value, a1 * (b2 - b1) / (a1 - a2) + b1)
+            self.assertAlmostEqual(res.incumbent_objective, m.y.value)
+            if res.objective_bound is None:
+                bound = -math.inf
+            else:
+                bound = res.objective_bound
+            self.assertTrue(bound <= m.y.value)
+
+    @parameterized.expand(input=_load_tests(all_solvers))
+    def test_no_objective(
+        self, name: str, opt_class: Type[SolverBase], use_presolve: bool
+    ):
+        opt: SolverBase = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        check_duals = True
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                check_duals = False
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.a1 = pe.Param(mutable=True)
+        m.a2 = pe.Param(mutable=True)
+        m.b1 = pe.Param(mutable=True)
+        m.b2 = pe.Param(mutable=True)
+        m.c1 = pe.Constraint(expr=m.y == m.a1 * m.x + m.b1)
+        m.c2 = pe.Constraint(expr=m.y == m.a2 * m.x + m.b2)
+
+        params_to_test = [(1, -1, 2, 1), (1, -2, 2, 1), (1, -1, 3, 1)]
+        for a1, a2, b1, b2 in params_to_test:
+            m.a1.value = a1
+            m.a2.value = a2
+            m.b1.value = b1
+            m.b2.value = b2
+            res: Results = opt.solve(m)
+            self.assertEqual(res.solution_status, SolutionStatus.optimal)
+            self.assertAlmostEqual(m.x.value, (b2 - b1) / (a1 - a2))
+            self.assertAlmostEqual(m.y.value, a1 * (b2 - b1) / (a1 - a2) + b1)
+            self.assertEqual(res.incumbent_objective, None)
+            self.assertEqual(res.objective_bound, None)
+            if check_duals:
+                duals = res.solution_loader.get_duals()
+                self.assertAlmostEqual(duals[m.c1], 0)
+                self.assertAlmostEqual(duals[m.c2], 0)
+
+    @parameterized.expand(input=_load_tests(all_solvers))
+    def test_add_remove_cons(
+        self, name: str, opt_class: Type[SolverBase], use_presolve: bool
+    ):
+        opt: SolverBase = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        a1 = -1
+        a2 = 1
+        b1 = 1
+        b2 = 2
+        a3 = 1
+        b3 = 3
+        m.obj = pe.Objective(expr=m.y)
+        m.c1 = pe.Constraint(expr=m.y >= a1 * m.x + b1)
+        m.c2 = pe.Constraint(expr=m.y >= a2 * m.x + b2)
+        res = opt.solve(m)
+        self.assertEqual(res.solution_status, SolutionStatus.optimal)
+        self.assertAlmostEqual(m.x.value, (b2 - b1) / (a1 - a2))
+        self.assertAlmostEqual(m.y.value, a1 * (b2 - b1) / (a1 - a2) + b1)
+        self.assertAlmostEqual(res.incumbent_objective, m.y.value)
+        if res.objective_bound is None:
+            bound = -math.inf
+        else:
+            bound = res.objective_bound
+        self.assertTrue(bound <= m.y.value)
+        duals = res.solution_loader.get_duals()
+        self.assertAlmostEqual(duals[m.c1], -(1 + a1 / (a2 - a1)))
+        self.assertAlmostEqual(duals[m.c2], a1 / (a2 - a1))
+
+        m.c3 = pe.Constraint(expr=m.y >= a3 * m.x + b3)
+        res = opt.solve(m)
+        self.assertEqual(res.solution_status, SolutionStatus.optimal)
+        self.assertAlmostEqual(m.x.value, (b3 - b1) / (a1 - a3))
+        self.assertAlmostEqual(m.y.value, a1 * (b3 - b1) / (a1 - a3) + b1)
+        self.assertAlmostEqual(res.incumbent_objective, m.y.value)
+        self.assertTrue(res.objective_bound is None or res.objective_bound <= m.y.value)
+        duals = res.solution_loader.get_duals()
+        self.assertAlmostEqual(duals[m.c1], -(1 + a1 / (a3 - a1)))
+        self.assertAlmostEqual(duals[m.c2], 0)
+        self.assertAlmostEqual(duals[m.c3], a1 / (a3 - a1))
+
+        del m.c3
+        res = opt.solve(m)
+        self.assertEqual(res.solution_status, SolutionStatus.optimal)
+        self.assertAlmostEqual(m.x.value, (b2 - b1) / (a1 - a2))
+        self.assertAlmostEqual(m.y.value, a1 * (b2 - b1) / (a1 - a2) + b1)
+        self.assertAlmostEqual(res.incumbent_objective, m.y.value)
+        self.assertTrue(res.objective_bound is None or res.objective_bound <= m.y.value)
+        duals = res.solution_loader.get_duals()
+        self.assertAlmostEqual(duals[m.c1], -(1 + a1 / (a2 - a1)))
+        self.assertAlmostEqual(duals[m.c2], a1 / (a2 - a1))
+
+    @parameterized.expand(input=_load_tests(all_solvers))
+    def test_results_infeasible(
+        self, name: str, opt_class: Type[SolverBase], use_presolve: bool
+    ):
+        opt: SolverBase = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.obj = pe.Objective(expr=m.y)
+        m.c1 = pe.Constraint(expr=m.y >= m.x)
+        m.c2 = pe.Constraint(expr=m.y <= m.x - 1)
+        with self.assertRaises(Exception):
+            res = opt.solve(m)
+        opt.config.load_solutions = False
+        opt.config.raise_exception_on_nonoptimal_result = False
+        res = opt.solve(m)
+        self.assertNotEqual(res.solution_status, SolutionStatus.optimal)
+        if isinstance(opt, Ipopt):
+            acceptable_termination_conditions = {
+                TerminationCondition.locallyInfeasible,
+                TerminationCondition.unbounded,
+            }
+        else:
+            acceptable_termination_conditions = {
+                TerminationCondition.provenInfeasible,
+                TerminationCondition.infeasibleOrUnbounded,
+            }
+        self.assertIn(res.termination_condition, acceptable_termination_conditions)
+        self.assertAlmostEqual(m.x.value, None)
+        self.assertAlmostEqual(m.y.value, None)
+        self.assertTrue(res.incumbent_objective is None)
+
+        if not isinstance(opt, Ipopt):
+            # ipopt can return the values of the variables/duals at the last iterate
+            # even if it did not converge; raise_exception_on_nonoptimal_result
+            # is set to False, so we are free to load infeasible solutions
+            with self.assertRaisesRegex(
+                RuntimeError, '.*does not currently have a valid solution.*'
+            ):
+                res.solution_loader.load_vars()
+            with self.assertRaisesRegex(
+                RuntimeError, '.*does not currently have valid duals.*'
+            ):
+                res.solution_loader.get_duals()
+            with self.assertRaisesRegex(
+                RuntimeError, '.*does not currently have valid reduced costs.*'
+            ):
+                res.solution_loader.get_reduced_costs()
+
+    @parameterized.expand(input=_load_tests(all_solvers))
+    def test_duals(self, name: str, opt_class: Type[SolverBase], use_presolve: bool):
+        opt: SolverBase = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.obj = pe.Objective(expr=m.y)
+        m.c1 = pe.Constraint(expr=m.y - m.x >= 0)
+        m.c2 = pe.Constraint(expr=m.y + m.x - 2 >= 0)
+
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.x.value, 1)
+        self.assertAlmostEqual(m.y.value, 1)
+        duals = res.solution_loader.get_duals()
+        self.assertAlmostEqual(duals[m.c1], 0.5)
+        self.assertAlmostEqual(duals[m.c2], 0.5)
+
+        duals = res.solution_loader.get_duals(cons_to_load=[m.c1])
+        self.assertAlmostEqual(duals[m.c1], 0.5)
+        self.assertNotIn(m.c2, duals)
+
+    @parameterized.expand(input=_load_tests(qcp_solvers))
+    def test_mutable_quadratic_coefficient(
+        self, name: str, opt_class: Type[SolverBase], use_presolve: bool
+    ):
+        opt: SolverBase = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.a = pe.Param(initialize=1, mutable=True)
+        m.b = pe.Param(initialize=-1, mutable=True)
+        m.obj = pe.Objective(expr=m.x**2 + m.y**2)
+        m.c = pe.Constraint(expr=m.y >= (m.a * m.x + m.b) ** 2)
+
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.x.value, 0.41024548525899274, 4)
+        self.assertAlmostEqual(m.y.value, 0.34781038127030117, 4)
+        m.a.value = 2
+        m.b.value = -0.5
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.x.value, 0.10256137418973625, 4)
+        self.assertAlmostEqual(m.y.value, 0.0869525991355825, 4)
+
+    @parameterized.expand(input=_load_tests(qcp_solvers))
+    def test_mutable_quadratic_objective(
+        self, name: str, opt_class: Type[SolverBase], use_presolve: bool
+    ):
+        opt: SolverBase = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.a = pe.Param(initialize=1, mutable=True)
+        m.b = pe.Param(initialize=-1, mutable=True)
+        m.c = pe.Param(initialize=1, mutable=True)
+        m.d = pe.Param(initialize=1, mutable=True)
+        m.obj = pe.Objective(expr=m.x**2 + m.c * m.y**2 + m.d * m.x)
+        m.ccon = pe.Constraint(expr=m.y >= (m.a * m.x + m.b) ** 2)
+
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.x.value, 0.2719178742733325, 4)
+        self.assertAlmostEqual(m.y.value, 0.5301035741688002, 4)
+        m.c.value = 3.5
+        m.d.value = -1
+        res = opt.solve(m)
+
+        self.assertAlmostEqual(m.x.value, 0.6962249634573562, 4)
+        self.assertAlmostEqual(m.y.value, 0.09227926676152151, 4)
+
+    @parameterized.expand(input=_load_tests(all_solvers))
+    def test_fixed_vars(
+        self, name: str, opt_class: Type[SolverBase], use_presolve: bool
+    ):
+        for treat_fixed_vars_as_params in [True, False]:
+            opt: SolverBase = opt_class()
+            if opt.is_persistent():
+                opt.config.auto_updates.treat_fixed_vars_as_params = (
+                    treat_fixed_vars_as_params
+                )
+            if not opt.available():
+                raise unittest.SkipTest(f'Solver {opt.name} not available.')
+            if any(name.startswith(i) for i in nl_solvers_set):
+                if use_presolve:
+                    opt.config.writer_config.linear_presolve = True
+                else:
+                    opt.config.writer_config.linear_presolve = False
+            m = pe.ConcreteModel()
+            m.x = pe.Var()
+            m.x.fix(0)
+            m.y = pe.Var()
+            a1 = 1
+            a2 = -1
+            b1 = 1
+            b2 = 2
+            m.obj = pe.Objective(expr=m.y)
+            m.c1 = pe.Constraint(expr=m.y >= a1 * m.x + b1)
+            m.c2 = pe.Constraint(expr=m.y >= a2 * m.x + b2)
+            res = opt.solve(m)
+            self.assertAlmostEqual(m.x.value, 0)
+            self.assertAlmostEqual(m.y.value, 2)
+            m.x.unfix()
+            res = opt.solve(m)
+            self.assertAlmostEqual(m.x.value, (b2 - b1) / (a1 - a2))
+            self.assertAlmostEqual(m.y.value, a1 * (b2 - b1) / (a1 - a2) + b1)
+            m.x.fix(0)
+            res = opt.solve(m)
+            self.assertAlmostEqual(m.x.value, 0)
+            self.assertAlmostEqual(m.y.value, 2)
+            m.x.value = 2
+            res = opt.solve(m)
+            self.assertAlmostEqual(m.x.value, 2)
+            self.assertAlmostEqual(m.y.value, 3)
+            m.x.value = 0
+            res = opt.solve(m)
+            self.assertAlmostEqual(m.x.value, 0)
+            self.assertAlmostEqual(m.y.value, 2)
+
+    @parameterized.expand(input=_load_tests(all_solvers))
+    def test_fixed_vars_2(
+        self, name: str, opt_class: Type[SolverBase], use_presolve: bool
+    ):
+        opt: SolverBase = opt_class()
+        if opt.is_persistent():
+            opt.config.auto_updates.treat_fixed_vars_as_params = True
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.x.fix(0)
+        m.y = pe.Var()
+        a1 = 1
+        a2 = -1
+        b1 = 1
+        b2 = 2
+        m.obj = pe.Objective(expr=m.y)
+        m.c1 = pe.Constraint(expr=m.y >= a1 * m.x + b1)
+        m.c2 = pe.Constraint(expr=m.y >= a2 * m.x + b2)
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.x.value, 0)
+        self.assertAlmostEqual(m.y.value, 2)
+        m.x.unfix()
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.x.value, (b2 - b1) / (a1 - a2))
+        self.assertAlmostEqual(m.y.value, a1 * (b2 - b1) / (a1 - a2) + b1)
+        m.x.fix(0)
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.x.value, 0)
+        self.assertAlmostEqual(m.y.value, 2)
+        m.x.value = 2
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.x.value, 2)
+        self.assertAlmostEqual(m.y.value, 3)
+        m.x.value = 0
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.x.value, 0)
+        self.assertAlmostEqual(m.y.value, 2)
+
+    @parameterized.expand(input=_load_tests(all_solvers))
+    def test_fixed_vars_3(
+        self, name: str, opt_class: Type[SolverBase], use_presolve: bool
+    ):
+        opt: SolverBase = opt_class()
+        if opt.is_persistent():
+            opt.config.auto_updates.treat_fixed_vars_as_params = True
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.obj = pe.Objective(expr=m.x + m.y)
+        m.c1 = pe.Constraint(expr=m.x == 2 / m.y)
+        m.y.fix(1)
+        res = opt.solve(m)
+        self.assertAlmostEqual(res.incumbent_objective, 3)
+        self.assertAlmostEqual(m.x.value, 2)
+
+    @parameterized.expand(input=_load_tests(nlp_solvers))
+    def test_fixed_vars_4(
+        self, name: str, opt_class: Type[SolverBase], use_presolve: bool
+    ):
+        opt: SolverBase = opt_class()
+        if opt.is_persistent():
+            opt.config.auto_updates.treat_fixed_vars_as_params = True
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.obj = pe.Objective(expr=m.x**2 + m.y**2)
+        m.c1 = pe.Constraint(expr=m.x == 2 / m.y)
+        m.y.fix(1)
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.x.value, 2)
+        m.y.unfix()
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.x.value, 2**0.5)
+        self.assertAlmostEqual(m.y.value, 2**0.5)
+
+    @parameterized.expand(input=_load_tests(all_solvers))
+    def test_mutable_param_with_range(
+        self, name: str, opt_class: Type[SolverBase], use_presolve: bool
+    ):
+        opt: SolverBase = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.a1 = pe.Param(initialize=0, mutable=True)
+        m.a2 = pe.Param(initialize=0, mutable=True)
+        m.b1 = pe.Param(initialize=0, mutable=True)
+        m.b2 = pe.Param(initialize=0, mutable=True)
+        m.c1 = pe.Param(initialize=0, mutable=True)
+        m.c2 = pe.Param(initialize=0, mutable=True)
+        m.obj = pe.Objective(expr=m.y)
+        m.con1 = pe.Constraint(expr=(m.b1, m.y - m.a1 * m.x, m.c1))
+        m.con2 = pe.Constraint(expr=(m.b2, m.y - m.a2 * m.x, m.c2))
+
+        np.random.seed(0)
+        params_to_test = [
+            (
+                np.random.uniform(0, 10),
+                np.random.uniform(-10, 0),
+                np.random.uniform(-5, 2.5),
+                np.random.uniform(-5, 2.5),
+                np.random.uniform(2.5, 10),
+                np.random.uniform(2.5, 10),
+                pe.minimize,
+            ),
+            (
+                np.random.uniform(0, 10),
+                np.random.uniform(-10, 0),
+                np.random.uniform(-5, 2.5),
+                np.random.uniform(-5, 2.5),
+                np.random.uniform(2.5, 10),
+                np.random.uniform(2.5, 10),
+                pe.maximize,
+            ),
+            (
+                np.random.uniform(0, 10),
+                np.random.uniform(-10, 0),
+                np.random.uniform(-5, 2.5),
+                np.random.uniform(-5, 2.5),
+                np.random.uniform(2.5, 10),
+                np.random.uniform(2.5, 10),
+                pe.minimize,
+            ),
+            (
+                np.random.uniform(0, 10),
+                np.random.uniform(-10, 0),
+                np.random.uniform(-5, 2.5),
+                np.random.uniform(-5, 2.5),
+                np.random.uniform(2.5, 10),
+                np.random.uniform(2.5, 10),
+                pe.maximize,
+            ),
+        ]
+        for a1, a2, b1, b2, c1, c2, sense in params_to_test:
+            m.a1.value = float(a1)
+            m.a2.value = float(a2)
+            m.b1.value = float(b1)
+            m.b2.value = float(b2)
+            m.c1.value = float(c1)
+            m.c2.value = float(c2)
+            m.obj.sense = sense
+            res: Results = opt.solve(m)
+            self.assertEqual(res.solution_status, SolutionStatus.optimal)
+            if sense is pe.minimize:
+                self.assertAlmostEqual(m.x.value, (b2 - b1) / (a1 - a2), 6)
+                self.assertAlmostEqual(m.y.value, a1 * (b2 - b1) / (a1 - a2) + b1, 6)
+                self.assertAlmostEqual(res.incumbent_objective, m.y.value, 6)
+                self.assertTrue(
+                    res.objective_bound is None
+                    or res.objective_bound <= m.y.value + 1e-12
+                )
+                duals = res.solution_loader.get_duals()
+                self.assertAlmostEqual(duals[m.con1], (1 + a1 / (a2 - a1)), 6)
+                self.assertAlmostEqual(duals[m.con2], -a1 / (a2 - a1), 6)
+            else:
+                self.assertAlmostEqual(m.x.value, (c2 - c1) / (a1 - a2), 6)
+                self.assertAlmostEqual(m.y.value, a1 * (c2 - c1) / (a1 - a2) + c1, 6)
+                self.assertAlmostEqual(res.incumbent_objective, m.y.value, 6)
+                self.assertTrue(
+                    res.objective_bound is None
+                    or res.objective_bound >= m.y.value - 1e-12
+                )
+                duals = res.solution_loader.get_duals()
+                self.assertAlmostEqual(duals[m.con1], (1 + a1 / (a2 - a1)), 6)
+                self.assertAlmostEqual(duals[m.con2], -a1 / (a2 - a1), 6)
+
+    @parameterized.expand(input=_load_tests(all_solvers))
+    def test_add_and_remove_vars(
+        self, name: str, opt_class: Type[SolverBase], use_presolve: bool
+    ):
+        opt = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+        m = pe.ConcreteModel()
+        m.y = pe.Var(bounds=(-1, None))
+        m.obj = pe.Objective(expr=m.y)
+        if opt.is_persistent():
+            opt.config.auto_updates.update_parameters = False
+            opt.config.auto_updates.update_vars = False
+            opt.config.auto_updates.update_constraints = False
+            opt.config.auto_updates.update_named_expressions = False
+            opt.config.auto_updates.check_for_new_or_removed_params = False
+            opt.config.auto_updates.check_for_new_or_removed_constraints = False
+            opt.config.auto_updates.check_for_new_or_removed_vars = False
+        opt.config.load_solutions = False
+        res = opt.solve(m)
+        self.assertEqual(res.solution_status, SolutionStatus.optimal)
+        res.solution_loader.load_vars()
+        self.assertAlmostEqual(m.y.value, -1)
+        m.x = pe.Var()
+        a1 = 1
+        a2 = -1
+        b1 = 2
+        b2 = 1
+        m.c1 = pe.Constraint(expr=(0, m.y - a1 * m.x - b1, None))
+        m.c2 = pe.Constraint(expr=(None, -m.y + a2 * m.x + b2, 0))
+        if opt.is_persistent():
+            opt.add_constraints([m.c1, m.c2])
+        res = opt.solve(m)
+        self.assertEqual(res.solution_status, SolutionStatus.optimal)
+        res.solution_loader.load_vars()
+        self.assertAlmostEqual(m.x.value, (b2 - b1) / (a1 - a2))
+        self.assertAlmostEqual(m.y.value, a1 * (b2 - b1) / (a1 - a2) + b1)
+        m.c1.deactivate()
+        m.c2.deactivate()
+        if opt.is_persistent():
+            opt.remove_constraints([m.c1, m.c2])
+        m.x.value = None
+        res = opt.solve(m)
+        self.assertEqual(res.solution_status, SolutionStatus.optimal)
+        res.solution_loader.load_vars()
+        self.assertEqual(m.x.value, None)
+        self.assertAlmostEqual(m.y.value, -1)
+
+    @parameterized.expand(input=_load_tests(nlp_solvers))
+    def test_exp(self, name: str, opt_class: Type[SolverBase], use_presolve: bool):
+        opt = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.obj = pe.Objective(expr=m.x**2 + m.y**2)
+        m.c1 = pe.Constraint(expr=m.y >= pe.exp(m.x))
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.x.value, -0.42630274815985264)
+        self.assertAlmostEqual(m.y.value, 0.6529186341994245)
+
+    @parameterized.expand(input=_load_tests(nlp_solvers))
+    def test_log(self, name: str, opt_class: Type[SolverBase], use_presolve: bool):
+        opt = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+        m = pe.ConcreteModel()
+        m.x = pe.Var(initialize=1)
+        m.y = pe.Var()
+        m.obj = pe.Objective(expr=m.x**2 + m.y**2)
+        m.c1 = pe.Constraint(expr=m.y <= pe.log(m.x))
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.x.value, 0.6529186341994245)
+        self.assertAlmostEqual(m.y.value, -0.42630274815985264)
+
+    @parameterized.expand(input=_load_tests(all_solvers))
+    def test_with_numpy(
+        self, name: str, opt_class: Type[SolverBase], use_presolve: bool
+    ):
+        opt: SolverBase = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.obj = pe.Objective(expr=m.y)
+        a1 = 1
+        b1 = 3
+        a2 = -2
+        b2 = 1
+        m.c1 = pe.Constraint(
+            expr=(np.float64(0), m.y - np.int64(1) * m.x - np.float32(3), None)
+        )
+        m.c2 = pe.Constraint(
+            expr=(None, -m.y + np.int32(-2) * m.x + np.float64(1), np.float16(0))
+        )
+        res = opt.solve(m)
+        self.assertEqual(res.solution_status, SolutionStatus.optimal)
+        self.assertAlmostEqual(m.x.value, (b2 - b1) / (a1 - a2))
+        self.assertAlmostEqual(m.y.value, a1 * (b2 - b1) / (a1 - a2) + b1)
+
+    @parameterized.expand(input=_load_tests(all_solvers))
+    def test_bounds_with_params(
+        self, name: str, opt_class: Type[SolverBase], use_presolve: bool
+    ):
+        opt: SolverBase = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+        m = pe.ConcreteModel()
+        m.y = pe.Var()
+        m.p = pe.Param(mutable=True)
+        m.y.setlb(m.p)
+        m.p.value = 1
+        m.obj = pe.Objective(expr=m.y)
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.y.value, 1)
+        m.p.value = -1
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.y.value, -1)
+        m.y.setlb(None)
+        m.y.setub(m.p)
+        m.obj.sense = pe.maximize
+        m.p.value = 5
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.y.value, 5)
+        m.p.value = 4
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.y.value, 4)
+        m.y.setub(None)
+        m.y.setlb(m.p)
+        m.obj.sense = pe.minimize
+        m.p.value = 3
+        res = opt.solve(m)
+        self.assertAlmostEqual(m.y.value, 3)
+
+    @parameterized.expand(input=_load_tests(all_solvers))
+    def test_solution_loader(
+        self, name: str, opt_class: Type[SolverBase], use_presolve: bool
+    ):
+        opt: SolverBase = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+        m = pe.ConcreteModel()
+        m.x = pe.Var(bounds=(1, None))
+        m.y = pe.Var()
+        m.obj = pe.Objective(expr=m.y)
+        m.c1 = pe.Constraint(expr=(0, m.y - m.x, None))
+        m.c2 = pe.Constraint(expr=(0, m.y - m.x + 1, None))
+        opt.config.load_solutions = False
+        res = opt.solve(m)
+        self.assertIsNone(m.x.value)
+        self.assertIsNone(m.y.value)
+        res.solution_loader.load_vars()
+        self.assertAlmostEqual(m.x.value, 1)
+        self.assertAlmostEqual(m.y.value, 1)
+        m.x.value = None
+        m.y.value = None
+        res.solution_loader.load_vars([m.y])
+        self.assertAlmostEqual(m.y.value, 1)
+        primals = res.solution_loader.get_primals()
+        self.assertIn(m.x, primals)
+        self.assertIn(m.y, primals)
+        self.assertAlmostEqual(primals[m.x], 1)
+        self.assertAlmostEqual(primals[m.y], 1)
+        primals = res.solution_loader.get_primals([m.y])
+        self.assertNotIn(m.x, primals)
+        self.assertIn(m.y, primals)
+        self.assertAlmostEqual(primals[m.y], 1)
+        reduced_costs = res.solution_loader.get_reduced_costs()
+        self.assertIn(m.x, reduced_costs)
+        self.assertIn(m.y, reduced_costs)
+        self.assertAlmostEqual(reduced_costs[m.x], 1)
+        self.assertAlmostEqual(reduced_costs[m.y], 0)
+        reduced_costs = res.solution_loader.get_reduced_costs([m.y])
+        self.assertNotIn(m.x, reduced_costs)
+        self.assertIn(m.y, reduced_costs)
+        self.assertAlmostEqual(reduced_costs[m.y], 0)
+        duals = res.solution_loader.get_duals()
+        self.assertIn(m.c1, duals)
+        self.assertIn(m.c2, duals)
+        self.assertAlmostEqual(duals[m.c1], 1)
+        self.assertAlmostEqual(duals[m.c2], 0)
+        duals = res.solution_loader.get_duals([m.c1])
+        self.assertNotIn(m.c2, duals)
+        self.assertIn(m.c1, duals)
+        self.assertAlmostEqual(duals[m.c1], 1)
+
+    @parameterized.expand(input=_load_tests(all_solvers))
+    def test_time_limit(
+        self, name: str, opt_class: Type[SolverBase], use_presolve: bool
+    ):
+        opt: SolverBase = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+        from sys import platform
+
+        if platform == 'win32':
+            raise unittest.SkipTest
+
+        N = 30
+        m = pe.ConcreteModel()
+        m.jobs = pe.Set(initialize=list(range(N)))
+        m.tasks = pe.Set(initialize=list(range(N)))
+        m.x = pe.Var(m.jobs, m.tasks, bounds=(0, 1))
+
+        random.seed(0)
+        coefs = list()
+        lin_vars = list()
+        for j in m.jobs:
+            for t in m.tasks:
+                coefs.append(random.uniform(0, 10))
+                lin_vars.append(m.x[j, t])
+        obj_expr = LinearExpression(
+            linear_coefs=coefs, linear_vars=lin_vars, constant=0
+        )
+        m.obj = pe.Objective(expr=obj_expr, sense=pe.maximize)
+
+        m.c1 = pe.Constraint(m.jobs)
+        m.c2 = pe.Constraint(m.tasks)
+        for j in m.jobs:
+            expr = LinearExpression(
+                linear_coefs=[1] * N,
+                linear_vars=[m.x[j, t] for t in m.tasks],
+                constant=0,
+            )
+            m.c1[j] = expr == 1
+        for t in m.tasks:
+            expr = LinearExpression(
+                linear_coefs=[1] * N,
+                linear_vars=[m.x[j, t] for j in m.jobs],
+                constant=0,
+            )
+            m.c2[t] = expr == 1
+        if isinstance(opt, Ipopt):
+            opt.config.time_limit = 1e-6
+        else:
+            opt.config.time_limit = 0
+        opt.config.load_solutions = False
+        opt.config.raise_exception_on_nonoptimal_result = False
+        res = opt.solve(m)
+        self.assertIn(
+            res.termination_condition,
+            {TerminationCondition.maxTimeLimit, TerminationCondition.iterationLimit},
+        )
+
+    @parameterized.expand(input=_load_tests(all_solvers))
+    def test_objective_changes(
+        self, name: str, opt_class: Type[SolverBase], use_presolve: bool
+    ):
+        opt: SolverBase = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.c1 = pe.Constraint(expr=m.y >= m.x + 1)
+        m.c2 = pe.Constraint(expr=m.y >= -m.x + 1)
+        m.obj = pe.Objective(expr=m.y)
+        res = opt.solve(m)
+        self.assertAlmostEqual(res.incumbent_objective, 1)
+        del m.obj
+        m.obj = pe.Objective(expr=2 * m.y)
+        res = opt.solve(m)
+        self.assertAlmostEqual(res.incumbent_objective, 2)
+        m.obj.expr = 3 * m.y
+        res = opt.solve(m)
+        self.assertAlmostEqual(res.incumbent_objective, 3)
+        m.obj.sense = pe.maximize
+        opt.config.raise_exception_on_nonoptimal_result = False
+        opt.config.load_solutions = False
+        res = opt.solve(m)
+        self.assertIn(
+            res.termination_condition,
+            {
+                TerminationCondition.unbounded,
+                TerminationCondition.infeasibleOrUnbounded,
+            },
+        )
+        m.obj.sense = pe.minimize
+        opt.config.load_solutions = True
+        del m.obj
+        m.obj = pe.Objective(expr=m.x * m.y)
+        m.x.fix(2)
+        res = opt.solve(m)
+        self.assertAlmostEqual(res.incumbent_objective, 6, 6)
+        m.x.fix(3)
+        res = opt.solve(m)
+        self.assertAlmostEqual(res.incumbent_objective, 12, 6)
+        m.x.unfix()
+        m.y.fix(2)
+        m.x.setlb(-3)
+        m.x.setub(5)
+        res = opt.solve(m)
+        self.assertAlmostEqual(res.incumbent_objective, -2, 6)
+        m.y.unfix()
+        m.x.setlb(None)
+        m.x.setub(None)
+        m.e = pe.Expression(expr=2)
+        del m.obj
+        m.obj = pe.Objective(expr=m.e * m.y)
+        res = opt.solve(m)
+        self.assertAlmostEqual(res.incumbent_objective, 2)
+        m.e.expr = 3
+        res = opt.solve(m)
+        self.assertAlmostEqual(res.incumbent_objective, 3)
+        if opt.is_persistent():
+            opt.config.auto_updates.check_for_new_objective = False
+            m.e.expr = 4
+            res = opt.solve(m)
+            self.assertAlmostEqual(res.incumbent_objective, 4)
+
+    @parameterized.expand(input=_load_tests(all_solvers))
+    def test_domain(self, name: str, opt_class: Type[SolverBase], use_presolve: bool):
+        opt: SolverBase = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+        m = pe.ConcreteModel()
+        m.x = pe.Var(bounds=(1, None), domain=pe.NonNegativeReals)
+        m.obj = pe.Objective(expr=m.x)
+        res = opt.solve(m)
+        self.assertAlmostEqual(res.incumbent_objective, 1)
+        m.x.setlb(-1)
+        res = opt.solve(m)
+        self.assertAlmostEqual(res.incumbent_objective, 0)
+        m.x.setlb(1)
+        res = opt.solve(m)
+        self.assertAlmostEqual(res.incumbent_objective, 1)
+        m.x.setlb(-1)
+        m.x.domain = pe.Reals
+        res = opt.solve(m)
+        self.assertAlmostEqual(res.incumbent_objective, -1)
+        m.x.domain = pe.NonNegativeReals
+        res = opt.solve(m)
+        self.assertAlmostEqual(res.incumbent_objective, 0)
+
+    @parameterized.expand(input=_load_tests(mip_solvers))
+    def test_domain_with_integers(
+        self, name: str, opt_class: Type[SolverBase], use_presolve: bool
+    ):
+        opt: SolverBase = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+        m = pe.ConcreteModel()
+        m.x = pe.Var(bounds=(-1, None), domain=pe.NonNegativeIntegers)
+        m.obj = pe.Objective(expr=m.x)
+        res = opt.solve(m)
+        self.assertAlmostEqual(res.incumbent_objective, 0)
+        m.x.setlb(0.5)
+        res = opt.solve(m)
+        self.assertAlmostEqual(res.incumbent_objective, 1)
+        m.x.setlb(-5.5)
+        m.x.domain = pe.Integers
+        res = opt.solve(m)
+        self.assertAlmostEqual(res.incumbent_objective, -5)
+        m.x.domain = pe.Binary
+        res = opt.solve(m)
+        self.assertAlmostEqual(res.incumbent_objective, 0)
+        m.x.setlb(0.5)
+        res = opt.solve(m)
+        self.assertAlmostEqual(res.incumbent_objective, 1)
+
+    @parameterized.expand(input=_load_tests(all_solvers))
+    def test_fixed_binaries(
+        self, name: str, opt_class: Type[SolverBase], use_presolve: bool
+    ):
+        opt: SolverBase = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+        m = pe.ConcreteModel()
+        m.x = pe.Var(domain=pe.Binary)
+        m.y = pe.Var()
+        m.obj = pe.Objective(expr=m.y)
+        m.c = pe.Constraint(expr=m.y >= m.x)
+        m.x.fix(0)
+        res = opt.solve(m)
+        self.assertAlmostEqual(res.incumbent_objective, 0)
+        m.x.fix(1)
+        res = opt.solve(m)
+        self.assertAlmostEqual(res.incumbent_objective, 1)
+
+        opt: SolverBase = opt_class()
+        if opt.is_persistent():
+            opt.config.auto_updates.treat_fixed_vars_as_params = False
+        m.x.fix(0)
+        res = opt.solve(m)
+        self.assertAlmostEqual(res.incumbent_objective, 0)
+        m.x.fix(1)
+        res = opt.solve(m)
+        self.assertAlmostEqual(res.incumbent_objective, 1)
+
+    @parameterized.expand(input=_load_tests(mip_solvers))
+    def test_with_gdp(self, name: str, opt_class: Type[SolverBase], use_presolve: bool):
+        opt: SolverBase = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+
+        m = pe.ConcreteModel()
+        m.x = pe.Var(bounds=(-10, 10))
+        m.y = pe.Var(bounds=(-10, 10))
+        m.obj = pe.Objective(expr=m.y)
+        m.d1 = gdp.Disjunct()
+        m.d1.c1 = pe.Constraint(expr=m.y >= m.x + 2)
+        m.d1.c2 = pe.Constraint(expr=m.y >= -m.x + 2)
+        m.d2 = gdp.Disjunct()
+        m.d2.c1 = pe.Constraint(expr=m.y >= m.x + 1)
+        m.d2.c2 = pe.Constraint(expr=m.y >= -m.x + 1)
+        m.disjunction = gdp.Disjunction(expr=[m.d2, m.d1])
+        pe.TransformationFactory("gdp.bigm").apply_to(m)
+
+        res = opt.solve(m)
+        self.assertAlmostEqual(res.incumbent_objective, 1)
+        self.assertAlmostEqual(m.x.value, 0)
+        self.assertAlmostEqual(m.y.value, 1)
+
+        opt: SolverBase = opt_class()
+        opt.use_extensions = True
+        res = opt.solve(m)
+        self.assertAlmostEqual(res.incumbent_objective, 1)
+        self.assertAlmostEqual(m.x.value, 0)
+        self.assertAlmostEqual(m.y.value, 1)
+
+    @parameterized.expand(input=_load_tests(all_solvers))
+    def test_variables_elsewhere(
+        self, name: str, opt_class: Type[SolverBase], use_presolve: bool
+    ):
+        opt: SolverBase = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.b = pe.Block()
+        m.b.obj = pe.Objective(expr=m.y)
+        m.b.c1 = pe.Constraint(expr=m.y >= m.x + 2)
+        m.b.c2 = pe.Constraint(expr=m.y >= -m.x)
+
+        res = opt.solve(m.b)
+        self.assertEqual(res.solution_status, SolutionStatus.optimal)
+        self.assertAlmostEqual(res.incumbent_objective, 1)
+        self.assertAlmostEqual(m.x.value, -1)
+        self.assertAlmostEqual(m.y.value, 1)
+
+        m.x.setlb(0)
+        res = opt.solve(m.b)
+        self.assertEqual(res.solution_status, SolutionStatus.optimal)
+        self.assertAlmostEqual(res.incumbent_objective, 2)
+        self.assertAlmostEqual(m.x.value, 0)
+        self.assertAlmostEqual(m.y.value, 2)
+
+    @parameterized.expand(input=_load_tests(all_solvers))
+    def test_variables_elsewhere2(
+        self, name: str, opt_class: Type[SolverBase], use_presolve: bool
+    ):
+        opt: SolverBase = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.z = pe.Var()
+
+        m.obj = pe.Objective(expr=m.y)
+        m.c1 = pe.Constraint(expr=m.y >= m.x)
+        m.c2 = pe.Constraint(expr=m.y >= -m.x)
+        m.c3 = pe.Constraint(expr=m.y >= m.z + 1)
+        m.c4 = pe.Constraint(expr=m.y >= -m.z + 1)
+
+        res = opt.solve(m)
+        self.assertEqual(res.solution_status, SolutionStatus.optimal)
+        self.assertAlmostEqual(res.incumbent_objective, 1)
+        sol = res.solution_loader.get_primals()
+        self.assertIn(m.x, sol)
+        self.assertIn(m.y, sol)
+        self.assertIn(m.z, sol)
+
+        del m.c3
+        del m.c4
+        res = opt.solve(m)
+        self.assertEqual(res.solution_status, SolutionStatus.optimal)
+        self.assertAlmostEqual(res.incumbent_objective, 0)
+        sol = res.solution_loader.get_primals()
+        self.assertIn(m.x, sol)
+        self.assertIn(m.y, sol)
+        self.assertNotIn(m.z, sol)
+
+    @parameterized.expand(input=_load_tests(all_solvers))
+    def test_bug_1(self, name: str, opt_class: Type[SolverBase], use_presolve: bool):
+        opt: SolverBase = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+
+        m = pe.ConcreteModel()
+        m.x = pe.Var(bounds=(3, 7))
+        m.y = pe.Var(bounds=(-10, 10))
+        m.p = pe.Param(mutable=True, initialize=0)
+
+        m.obj = pe.Objective(expr=m.y)
+        m.c = pe.Constraint(expr=m.y >= m.p * m.x)
+
+        res = opt.solve(m)
+        self.assertEqual(res.solution_status, SolutionStatus.optimal)
+        self.assertAlmostEqual(res.incumbent_objective, 0)
+
+        m.p.value = 1
+        res = opt.solve(m)
+        self.assertEqual(res.solution_status, SolutionStatus.optimal)
+        self.assertAlmostEqual(res.incumbent_objective, 3)
+
+    @parameterized.expand(input=_load_tests(all_solvers))
+    def test_bug_2(self, name: str, opt_class: Type[SolverBase], use_presolve: bool):
+        """
+        This test is for a bug where an objective containing a fixed variable does
+        not get updated properly when the variable is unfixed.
+        """
+        for fixed_var_option in [True, False]:
+            opt: SolverBase = opt_class()
+            if not opt.available():
+                raise unittest.SkipTest(f'Solver {opt.name} not available.')
+            if any(name.startswith(i) for i in nl_solvers_set):
+                if use_presolve:
+                    opt.config.writer_config.linear_presolve = True
+                else:
+                    opt.config.writer_config.linear_presolve = False
+            if opt.is_persistent():
+                opt.config.auto_updates.treat_fixed_vars_as_params = fixed_var_option
+
+            m = pe.ConcreteModel()
+            m.x = pe.Var(bounds=(-10, 10))
+            m.y = pe.Var()
+            m.obj = pe.Objective(expr=3 * m.y - m.x)
+            m.c = pe.Constraint(expr=m.y >= m.x)
+
+            m.x.fix(1)
+            res = opt.solve(m)
+            self.assertAlmostEqual(res.incumbent_objective, 2, 5)
+
+            m.x.unfix()
+            m.x.setlb(-9)
+            m.x.setub(9)
+            res = opt.solve(m)
+            self.assertAlmostEqual(res.incumbent_objective, -18, 5)
+
+    @parameterized.expand(input=_load_tests(nl_solvers))
+    def test_presolve_with_zero_coef(
+        self, name: str, opt_class: Type[SolverBase], use_presolve: bool
+    ):
+        opt: SolverBase = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        if use_presolve:
+            opt.config.writer_config.linear_presolve = True
+        else:
+            opt.config.writer_config.linear_presolve = False
+
+        """
+        when c2 gets presolved out, c1 becomes 
+        x - y + y = 0 which becomes
+        x - 0*y == 0 which is the zero we are testing for
+        """
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.z = pe.Var()
+        m.obj = pe.Objective(expr=m.x**2 + m.y**2 + m.z**2)
+        m.c1 = pe.Constraint(expr=m.x == m.y + m.z + 1.5)
+        m.c2 = pe.Constraint(expr=m.z == -m.y)
+
+        res = opt.solve(m)
+        self.assertAlmostEqual(res.incumbent_objective, 2.25)
+        self.assertAlmostEqual(m.x.value, 1.5)
+        self.assertAlmostEqual(m.y.value, 0)
+        self.assertAlmostEqual(m.z.value, 0)
+
+        m.x.setlb(2)
+        res = opt.solve(
+            m, load_solutions=False, raise_exception_on_nonoptimal_result=False
+        )
+        if use_presolve:
+            exp = TerminationCondition.provenInfeasible
+        else:
+            exp = TerminationCondition.locallyInfeasible
+        self.assertEqual(res.termination_condition, exp)
+
+        m = pe.ConcreteModel()
+        m.w = pe.Var()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.z = pe.Var()
+        m.obj = pe.Objective(expr=m.x**2 + m.y**2 + m.z**2 + m.w**2)
+        m.c1 = pe.Constraint(expr=m.x + m.w == m.y + m.z)
+        m.c2 = pe.Constraint(expr=m.z == -m.y)
+        m.c3 = pe.Constraint(expr=m.x == -m.w)
+
+        res = opt.solve(m)
+        self.assertAlmostEqual(res.incumbent_objective, 0)
+        self.assertAlmostEqual(m.w.value, 0)
+        self.assertAlmostEqual(m.x.value, 0)
+        self.assertAlmostEqual(m.y.value, 0)
+        self.assertAlmostEqual(m.z.value, 0)
+
+        del m.c1
+        m.c1 = pe.Constraint(expr=m.x + m.w == m.y + m.z + 1.5)
+        res = opt.solve(
+            m, load_solutions=False, raise_exception_on_nonoptimal_result=False
+        )
+        self.assertEqual(res.termination_condition, exp)
+
+    @parameterized.expand(input=_load_tests(all_solvers))
+    def test_scaling(self, name: str, opt_class: Type[SolverBase], use_presolve: bool):
+        opt: SolverBase = opt_class()
+        if not opt.available():
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        check_duals = True
+        if any(name.startswith(i) for i in nl_solvers_set):
+            if use_presolve:
+                check_duals = False
+                opt.config.writer_config.linear_presolve = True
+            else:
+                opt.config.writer_config.linear_presolve = False
+
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.obj = pe.Objective(expr=m.y)
+        m.c1 = pe.Constraint(expr=m.y >= (m.x - 1) + 1)
+        m.c2 = pe.Constraint(expr=m.y >= -(m.x - 1) + 1)
+        m.scaling_factor = pe.Suffix(direction=pe.Suffix.EXPORT)
+        m.scaling_factor[m.x] = 0.5
+        m.scaling_factor[m.y] = 2
+        m.scaling_factor[m.c1] = 0.5
+        m.scaling_factor[m.c2] = 2
+        m.scaling_factor[m.obj] = 2
+
+        res = opt.solve(m)
+        self.assertAlmostEqual(res.incumbent_objective, 1)
+        self.assertAlmostEqual(m.x.value, 1)
+        self.assertAlmostEqual(m.y.value, 1)
+        primals = res.solution_loader.get_primals()
+        self.assertAlmostEqual(primals[m.x], 1)
+        self.assertAlmostEqual(primals[m.y], 1)
+        if check_duals:
+            duals = res.solution_loader.get_duals()
+            self.assertAlmostEqual(duals[m.c1], -0.5)
+            self.assertAlmostEqual(duals[m.c2], -0.5)
+            rc = res.solution_loader.get_reduced_costs()
+            self.assertAlmostEqual(rc[m.x], 0)
+            self.assertAlmostEqual(rc[m.y], 0)
+
+        m.x.setlb(2)
+        res = opt.solve(m)
+        self.assertAlmostEqual(res.incumbent_objective, 2)
+        self.assertAlmostEqual(m.x.value, 2)
+        self.assertAlmostEqual(m.y.value, 2)
+        primals = res.solution_loader.get_primals()
+        self.assertAlmostEqual(primals[m.x], 2)
+        self.assertAlmostEqual(primals[m.y], 2)
+        if check_duals:
+            duals = res.solution_loader.get_duals()
+            self.assertAlmostEqual(duals[m.c1], -1)
+            self.assertAlmostEqual(duals[m.c2], 0)
+            rc = res.solution_loader.get_reduced_costs()
+            self.assertAlmostEqual(rc[m.x], 1)
+            self.assertAlmostEqual(rc[m.y], 0)
+
+
+class TestLegacySolverInterface(unittest.TestCase):
+    @parameterized.expand(input=all_solvers)
+    def test_param_updates(self, name: str, opt_class: Type[SolverBase]):
+        opt = pe.SolverFactory(name + '_v2')
+        if not opt.available(exception_flag=False):
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.y = pe.Var()
+        m.a1 = pe.Param(mutable=True)
+        m.a2 = pe.Param(mutable=True)
+        m.b1 = pe.Param(mutable=True)
+        m.b2 = pe.Param(mutable=True)
+        m.obj = pe.Objective(expr=m.y)
+        m.c1 = pe.Constraint(expr=(0, m.y - m.a1 * m.x - m.b1, None))
+        m.c2 = pe.Constraint(expr=(None, -m.y + m.a2 * m.x + m.b2, 0))
+        m.dual = pe.Suffix(direction=pe.Suffix.IMPORT)
+
+        params_to_test = [(1, -1, 2, 1), (1, -2, 2, 1), (1, -1, 3, 1)]
+        for a1, a2, b1, b2 in params_to_test:
+            m.a1.value = a1
+            m.a2.value = a2
+            m.b1.value = b1
+            m.b2.value = b2
+            res = opt.solve(m)
+            pe.assert_optimal_termination(res)
+            self.assertAlmostEqual(m.x.value, (b2 - b1) / (a1 - a2))
+            self.assertAlmostEqual(m.y.value, a1 * (b2 - b1) / (a1 - a2) + b1)
+            self.assertAlmostEqual(m.dual[m.c1], (1 + a1 / (a2 - a1)))
+            self.assertAlmostEqual(m.dual[m.c2], a1 / (a2 - a1))
+
+    @parameterized.expand(input=all_solvers)
+    def test_load_solutions(self, name: str, opt_class: Type[SolverBase]):
+        opt = pe.SolverFactory(name + '_v2')
+        if not opt.available(exception_flag=False):
+            raise unittest.SkipTest(f'Solver {opt.name} not available.')
+        m = pe.ConcreteModel()
+        m.x = pe.Var()
+        m.obj = pe.Objective(expr=m.x)
+        m.c = pe.Constraint(expr=(-1, m.x, 1))
+        m.dual = pe.Suffix(direction=pe.Suffix.IMPORT)
+        res = opt.solve(m, load_solutions=False)
+        pe.assert_optimal_termination(res)
+        self.assertIsNone(m.x.value)
+        self.assertNotIn(m.c, m.dual)
+        m.solutions.load_from(res)
+        self.assertAlmostEqual(m.x.value, -1)
+        self.assertAlmostEqual(m.dual[m.c], 1)
diff --git a/pyomo/contrib/solver/tests/unit/__init__.py b/pyomo/contrib/solver/tests/unit/__init__.py
new file mode 100644
index 00000000000..a4a626013c4
--- /dev/null
+++ b/pyomo/contrib/solver/tests/unit/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/solver/tests/unit/sol_files/__init__.py b/pyomo/contrib/solver/tests/unit/sol_files/__init__.py
new file mode 100644
index 00000000000..a4a626013c4
--- /dev/null
+++ b/pyomo/contrib/solver/tests/unit/sol_files/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/solver/tests/unit/sol_files/bad_objno.sol b/pyomo/contrib/solver/tests/unit/sol_files/bad_objno.sol
new file mode 100644
index 00000000000..a7eccfca388
--- /dev/null
+++ b/pyomo/contrib/solver/tests/unit/sol_files/bad_objno.sol
@@ -0,0 +1,22 @@
+CONOPT 3.17A: Optimal; objective 1
+4 iterations; evals: nf = 2, ng = 0, nc = 2, nJ = 0, nH = 0, nHv = 0
+
+Options
+3
+1
+1
+0
+1
+1
+1
+1
+1
+1
+Xobjno 0 0
+suffix 0 1 8 0 0
+sstatus
+0 1
+suffix 1 1 8 0 0
+sstatus
+0 3
+
diff --git a/pyomo/contrib/solver/tests/unit/sol_files/bad_objnoline.sol b/pyomo/contrib/solver/tests/unit/sol_files/bad_objnoline.sol
new file mode 100644
index 00000000000..6abcacbb3c4
--- /dev/null
+++ b/pyomo/contrib/solver/tests/unit/sol_files/bad_objnoline.sol
@@ -0,0 +1,22 @@
+CONOPT 3.17A: Optimal; objective 1
+4 iterations; evals: nf = 2, ng = 0, nc = 2, nJ = 0, nH = 0, nHv = 0
+
+Options
+3
+1
+1
+0
+1
+1
+1
+1
+1
+1
+objno 0 0 1
+suffix 0 1 8 0 0
+sstatus
+0 1
+suffix 1 1 8 0 0
+sstatus
+0 3
+
diff --git a/pyomo/contrib/solver/tests/unit/sol_files/bad_options.sol b/pyomo/contrib/solver/tests/unit/sol_files/bad_options.sol
new file mode 100644
index 00000000000..f59a2ffd3b4
--- /dev/null
+++ b/pyomo/contrib/solver/tests/unit/sol_files/bad_options.sol
@@ -0,0 +1,22 @@
+CONOPT 3.17A: Optimal; objective 1
+4 iterations; evals: nf = 2, ng = 0, nc = 2, nJ = 0, nH = 0, nHv = 0
+
+OXptions
+3
+1
+1
+0
+1
+1
+1
+1
+1
+1
+objno 0 0
+suffix 0 1 8 0 0
+sstatus
+0 1
+suffix 1 1 8 0 0
+sstatus
+0 3
+
diff --git a/pyomo/contrib/solver/tests/unit/sol_files/conopt_optimal.sol b/pyomo/contrib/solver/tests/unit/sol_files/conopt_optimal.sol
new file mode 100644
index 00000000000..4ff14b50bc7
--- /dev/null
+++ b/pyomo/contrib/solver/tests/unit/sol_files/conopt_optimal.sol
@@ -0,0 +1,22 @@
+CONOPT 3.17A: Optimal; objective 1
+4 iterations; evals: nf = 2, ng = 0, nc = 2, nJ = 0, nH = 0, nHv = 0
+
+Options
+3
+1
+1
+0
+1
+1
+1
+1
+1
+1
+objno 0 0
+suffix 0 1 8 0 0
+sstatus
+0 1
+suffix 1 1 8 0 0
+sstatus
+0 3
+
diff --git a/pyomo/contrib/solver/tests/unit/sol_files/depr_solver.sol b/pyomo/contrib/solver/tests/unit/sol_files/depr_solver.sol
new file mode 100644
index 00000000000..01ceb566334
--- /dev/null
+++ b/pyomo/contrib/solver/tests/unit/sol_files/depr_solver.sol
@@ -0,0 +1,67 @@
+PICO Solver: final f = 88.200000
+
+Options
+3
+0
+0
+0
+24
+24
+32
+32
+0
+0
+0.12599999999999997
+0
+0
+0
+0
+0
+0
+0
+0
+0
+0
+0
+0
+0
+0
+0
+0
+0
+0
+0
+0
+0
+0
+0
+0
+0
+46.666666666666664
+0
+0
+0
+0
+0
+0
+933.3333333333336
+10000
+10000
+10000
+10000
+0
+100
+0
+100
+0
+100
+0
+100
+46.666666666666664
+53.333333333333336
+0
+100
+0
+100
+0
+100
diff --git a/pyomo/contrib/solver/tests/unit/sol_files/iis_no_variable_values.sol b/pyomo/contrib/solver/tests/unit/sol_files/iis_no_variable_values.sol
new file mode 100644
index 00000000000..641a3162a8f
--- /dev/null
+++ b/pyomo/contrib/solver/tests/unit/sol_files/iis_no_variable_values.sol
@@ -0,0 +1,34 @@
+CPLEX 12.8.0.0: integer infeasible.
+0 MIP simplex iterations
+0 branch-and-bound nodes
+Returning an IIS of 2 variables and 1 constraints.
+No basis.
+
+Options
+3
+1
+1
+0
+1
+0
+2
+0
+objno 0 220
+suffix 0 2 4 181 11
+iis
+
+0	non	not in the iis
+1	low	at lower bound
+2	fix	fixed
+3	upp	at upper bound
+4	mem	member
+5	pmem	possible member
+6	plow	possibly at lower bound
+7	pupp	possibly at upper bound
+8	bug
+
+0 1
+1 1
+suffix 1 1 4 0 0
+iis
+0 4
diff --git a/pyomo/contrib/solver/tests/unit/sol_files/infeasible1.sol b/pyomo/contrib/solver/tests/unit/sol_files/infeasible1.sol
new file mode 100644
index 00000000000..9e7c47f2091
--- /dev/null
+++ b/pyomo/contrib/solver/tests/unit/sol_files/infeasible1.sol
@@ -0,0 +1,491 @@
+ 
+Ipopt 3.12: Converged to a locally infeasible point. Problem may be infeasible.
+
+Options
+3
+1
+1
+0
+242
+242
+86
+86
+-3.5031247438024307e-14
+-3.5234584915901186e-14
+-3.5172095867741636e-14
+-3.530546013164763e-14
+-3.5172095867741636e-14
+-3.5305460131648396e-14
+-2.366093398247632e-13
+-2.3660933995816667e-13
+-2.366093403160036e-13
+-2.366093402111279e-13
+-2.366093403160036e-13
+-2.366093402111279e-13
+-3.230618014133495e-14
+-3.229008861611988e-14
+-3.2372291959738883e-14
+-3.233107904711923e-14
+-3.2372291959738883e-14
+-3.233107904711986e-14
+-2.366093402825742e-13
+-2.3660934046399004e-13
+-2.366093408240676e-13
+-2.3660934074259244e-13
+-2.366093408240676e-13
+-2.3660934074259244e-13
+-3.5337260190603076e-15
+-3.5384985959538063e-15
+-3.5360752870197467e-15
+-3.5401103667524204e-15
+-3.5360752870197475e-15
+-3.540110366752954e-15
+-1.1241014244910024e-13
+-7.229408362081387e-14
+-1.1241014257725814e-13
+-7.229408365067014e-14
+-1.1241014257725814e-13
+-7.229408365067014e-14
+-0.045045044618550245
+-2.2503048100082865e-13
+-0.04504504461894986
+-2.3019280438209537e-13
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diff --git a/pyomo/contrib/solver/tests/unit/sol_files/infeasible2.sol b/pyomo/contrib/solver/tests/unit/sol_files/infeasible2.sol
new file mode 100644
index 00000000000..6fddb053745
--- /dev/null
+++ b/pyomo/contrib/solver/tests/unit/sol_files/infeasible2.sol
@@ -0,0 +1,13 @@
+
+ Couenne (C:\Users\SASCHA~1\AppData\Local\Temp\tmpvcmknhw0.pyomo.nl May 18 2015): Infeasible
+
+Options
+3
+0
+1
+0
+242
+0
+86
+0
+objno 0 220
diff --git a/pyomo/contrib/solver/tests/unit/test_base.py b/pyomo/contrib/solver/tests/unit/test_base.py
new file mode 100644
index 00000000000..b52f96ba903
--- /dev/null
+++ b/pyomo/contrib/solver/tests/unit/test_base.py
@@ -0,0 +1,374 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import os
+
+from pyomo.common import unittest
+from pyomo.common.config import ConfigDict
+from pyomo.contrib.solver import base
+
+
+class TestSolverBase(unittest.TestCase):
+    def test_abstract_member_list(self):
+        expected_list = ['solve', 'available', 'version']
+        member_list = list(base.SolverBase.__abstractmethods__)
+        self.assertEqual(sorted(expected_list), sorted(member_list))
+
+    def test_class_method_list(self):
+        expected_list = [
+            'Availability',
+            'CONFIG',
+            'available',
+            'is_persistent',
+            'solve',
+            'version',
+        ]
+        method_list = [
+            method for method in dir(base.SolverBase) if method.startswith('_') is False
+        ]
+        self.assertEqual(sorted(expected_list), sorted(method_list))
+
+    @unittest.mock.patch.multiple(base.SolverBase, __abstractmethods__=set())
+    def test_init(self):
+        self.instance = base.SolverBase()
+        self.assertFalse(self.instance.is_persistent())
+        self.assertEqual(self.instance.version(), None)
+        self.assertEqual(self.instance.name, 'solverbase')
+        self.assertEqual(self.instance.CONFIG, self.instance.config)
+        self.assertEqual(self.instance.solve(None), None)
+        self.assertEqual(self.instance.available(), None)
+
+    @unittest.mock.patch.multiple(base.SolverBase, __abstractmethods__=set())
+    def test_context_manager(self):
+        with base.SolverBase() as self.instance:
+            self.assertFalse(self.instance.is_persistent())
+            self.assertEqual(self.instance.version(), None)
+            self.assertEqual(self.instance.name, 'solverbase')
+            self.assertEqual(self.instance.CONFIG, self.instance.config)
+            self.assertEqual(self.instance.solve(None), None)
+            self.assertEqual(self.instance.available(), None)
+
+    @unittest.mock.patch.multiple(base.SolverBase, __abstractmethods__=set())
+    def test_config_kwds(self):
+        self.instance = base.SolverBase(tee=True)
+        self.assertTrue(self.instance.config.tee)
+
+    @unittest.mock.patch.multiple(base.SolverBase, __abstractmethods__=set())
+    def test_solver_availability(self):
+        self.instance = base.SolverBase()
+        self.instance.Availability._value_ = 1
+        self.assertTrue(self.instance.Availability.__bool__(self.instance.Availability))
+        self.instance.Availability._value_ = -1
+        self.assertFalse(
+            self.instance.Availability.__bool__(self.instance.Availability)
+        )
+
+    @unittest.mock.patch.multiple(base.SolverBase, __abstractmethods__=set())
+    def test_custom_solver_name(self):
+        self.instance = base.SolverBase(name='my_unique_name')
+        self.assertEqual(self.instance.name, 'my_unique_name')
+
+
+class TestPersistentSolverBase(unittest.TestCase):
+    def test_abstract_member_list(self):
+        expected_list = [
+            'remove_parameters',
+            'version',
+            'update_variables',
+            'remove_variables',
+            'add_constraints',
+            '_get_primals',
+            'set_instance',
+            'set_objective',
+            'update_parameters',
+            'remove_block',
+            'add_block',
+            'available',
+            'add_parameters',
+            'remove_constraints',
+            'add_variables',
+            'solve',
+        ]
+        member_list = list(base.PersistentSolverBase.__abstractmethods__)
+        self.assertEqual(sorted(expected_list), sorted(member_list))
+
+    def test_class_method_list(self):
+        expected_list = [
+            'Availability',
+            'CONFIG',
+            '_get_duals',
+            '_get_primals',
+            '_get_reduced_costs',
+            '_load_vars',
+            'add_block',
+            'add_constraints',
+            'add_parameters',
+            'add_variables',
+            'available',
+            'is_persistent',
+            'remove_block',
+            'remove_constraints',
+            'remove_parameters',
+            'remove_variables',
+            'set_instance',
+            'set_objective',
+            'solve',
+            'update_parameters',
+            'update_variables',
+            'version',
+        ]
+        method_list = [
+            method
+            for method in dir(base.PersistentSolverBase)
+            if (method.startswith('__') or method.startswith('_abc')) is False
+        ]
+        self.assertEqual(sorted(expected_list), sorted(method_list))
+
+    @unittest.mock.patch.multiple(base.PersistentSolverBase, __abstractmethods__=set())
+    def test_init(self):
+        self.instance = base.PersistentSolverBase()
+        self.assertTrue(self.instance.is_persistent())
+        self.assertEqual(self.instance.set_instance(None), None)
+        self.assertEqual(self.instance.add_variables(None), None)
+        self.assertEqual(self.instance.add_parameters(None), None)
+        self.assertEqual(self.instance.add_constraints(None), None)
+        self.assertEqual(self.instance.add_block(None), None)
+        self.assertEqual(self.instance.remove_variables(None), None)
+        self.assertEqual(self.instance.remove_parameters(None), None)
+        self.assertEqual(self.instance.remove_constraints(None), None)
+        self.assertEqual(self.instance.remove_block(None), None)
+        self.assertEqual(self.instance.set_objective(None), None)
+        self.assertEqual(self.instance.update_variables(None), None)
+        self.assertEqual(self.instance.update_parameters(), None)
+
+        with self.assertRaises(NotImplementedError):
+            self.instance._get_primals()
+
+        with self.assertRaises(NotImplementedError):
+            self.instance._get_duals()
+
+        with self.assertRaises(NotImplementedError):
+            self.instance._get_reduced_costs()
+
+    @unittest.mock.patch.multiple(base.PersistentSolverBase, __abstractmethods__=set())
+    def test_context_manager(self):
+        with base.PersistentSolverBase() as self.instance:
+            self.assertTrue(self.instance.is_persistent())
+            self.assertEqual(self.instance.set_instance(None), None)
+            self.assertEqual(self.instance.add_variables(None), None)
+            self.assertEqual(self.instance.add_parameters(None), None)
+            self.assertEqual(self.instance.add_constraints(None), None)
+            self.assertEqual(self.instance.add_block(None), None)
+            self.assertEqual(self.instance.remove_variables(None), None)
+            self.assertEqual(self.instance.remove_parameters(None), None)
+            self.assertEqual(self.instance.remove_constraints(None), None)
+            self.assertEqual(self.instance.remove_block(None), None)
+            self.assertEqual(self.instance.set_objective(None), None)
+            self.assertEqual(self.instance.update_variables(None), None)
+            self.assertEqual(self.instance.update_parameters(), None)
+
+
+class TestLegacySolverWrapper(unittest.TestCase):
+    def test_class_method_list(self):
+        expected_list = [
+            'available',
+            'config_block',
+            'license_is_valid',
+            'set_options',
+            'solve',
+        ]
+        method_list = [
+            method
+            for method in dir(base.LegacySolverWrapper)
+            if method.startswith('_') is False
+        ]
+        self.assertEqual(sorted(expected_list), sorted(method_list))
+
+    def test_context_manager(self):
+        with base.LegacySolverWrapper() as instance:
+            with self.assertRaises(AttributeError):
+                instance.available()
+
+    def test_map_config(self):
+        # Create a fake/empty config structure that can be added to an empty
+        # instance of LegacySolverWrapper
+        self.config = ConfigDict(implicit=True)
+        self.config.declare(
+            'solver_options',
+            ConfigDict(implicit=True, description="Options to pass to the solver."),
+        )
+        instance = base.LegacySolverWrapper()
+        instance.config = self.config
+        instance._map_config(
+            True, False, False, 20, True, False, None, None, None, False, None, None
+        )
+        self.assertTrue(instance.config.tee)
+        self.assertFalse(instance.config.load_solutions)
+        self.assertEqual(instance.config.time_limit, 20)
+        self.assertEqual(instance.config.report_timing, True)
+        # Keepfiles should not be created because we did not declare keepfiles on
+        # the original config
+        with self.assertRaises(AttributeError):
+            print(instance.config.keepfiles)
+        # We haven't implemented solver_io, suffixes, or logfile
+        with self.assertRaises(NotImplementedError):
+            instance._map_config(
+                False,
+                False,
+                False,
+                20,
+                False,
+                False,
+                None,
+                None,
+                '/path/to/bogus/file',
+                False,
+                None,
+                None,
+            )
+        with self.assertRaises(NotImplementedError):
+            instance._map_config(
+                False,
+                False,
+                False,
+                20,
+                False,
+                False,
+                None,
+                '/path/to/bogus/file',
+                None,
+                False,
+                None,
+                None,
+            )
+        with self.assertRaises(NotImplementedError):
+            instance._map_config(
+                False,
+                False,
+                False,
+                20,
+                False,
+                False,
+                '/path/to/bogus/file',
+                None,
+                None,
+                False,
+                None,
+                None,
+            )
+        # If they ask for keepfiles, we redirect them to working_dir
+        instance._map_config(
+            False, False, False, 20, False, False, None, None, None, True, None, None
+        )
+        self.assertEqual(instance.config.working_dir, os.getcwd())
+        with self.assertRaises(AttributeError):
+            print(instance.config.keepfiles)
+
+    def test_solver_options_behavior(self):
+        # options can work in multiple ways (set from instantiation, set
+        # after instantiation, set during solve).
+        # Test case 1: Set at instantiation
+        solver = base.LegacySolverWrapper(options={'max_iter': 6})
+        self.assertEqual(solver.options, {'max_iter': 6})
+
+        # Test case 2: Set later
+        solver = base.LegacySolverWrapper()
+        solver.options = {'max_iter': 4, 'foo': 'bar'}
+        self.assertEqual(solver.options, {'max_iter': 4, 'foo': 'bar'})
+
+        # Test case 3: pass some options to the mapping (aka, 'solve' command)
+        solver = base.LegacySolverWrapper()
+        config = ConfigDict(implicit=True)
+        config.declare(
+            'solver_options',
+            ConfigDict(implicit=True, description="Options to pass to the solver."),
+        )
+        solver.config = config
+        solver._map_config(options={'max_iter': 4})
+        self.assertEqual(solver.config.solver_options, {'max_iter': 4})
+
+        # Test case 4: Set at instantiation and override during 'solve' call
+        solver = base.LegacySolverWrapper(options={'max_iter': 6})
+        config = ConfigDict(implicit=True)
+        config.declare(
+            'solver_options',
+            ConfigDict(implicit=True, description="Options to pass to the solver."),
+        )
+        solver.config = config
+        solver._map_config(options={'max_iter': 4})
+        self.assertEqual(solver.config.solver_options, {'max_iter': 4})
+        self.assertEqual(solver.options, {'max_iter': 6})
+
+        # solver_options are also supported
+        # Test case 1: set at instantiation
+        solver = base.LegacySolverWrapper(solver_options={'max_iter': 6})
+        self.assertEqual(solver.options, {'max_iter': 6})
+
+        # Test case 2: pass some solver_options to the mapping (aka, 'solve' command)
+        solver = base.LegacySolverWrapper()
+        config = ConfigDict(implicit=True)
+        config.declare(
+            'solver_options',
+            ConfigDict(implicit=True, description="Options to pass to the solver."),
+        )
+        solver.config = config
+        solver._map_config(solver_options={'max_iter': 4})
+        self.assertEqual(solver.config.solver_options, {'max_iter': 4})
+
+        # Test case 3: Set at instantiation and override during 'solve' call
+        solver = base.LegacySolverWrapper(solver_options={'max_iter': 6})
+        config = ConfigDict(implicit=True)
+        config.declare(
+            'solver_options',
+            ConfigDict(implicit=True, description="Options to pass to the solver."),
+        )
+        solver.config = config
+        solver._map_config(solver_options={'max_iter': 4})
+        self.assertEqual(solver.config.solver_options, {'max_iter': 4})
+        self.assertEqual(solver.options, {'max_iter': 6})
+
+        # users can mix... sort of
+        # Test case 1: Initialize with options, solve with solver_options
+        solver = base.LegacySolverWrapper(options={'max_iter': 6})
+        config = ConfigDict(implicit=True)
+        config.declare(
+            'solver_options',
+            ConfigDict(implicit=True, description="Options to pass to the solver."),
+        )
+        solver.config = config
+        solver._map_config(solver_options={'max_iter': 4})
+        self.assertEqual(solver.config.solver_options, {'max_iter': 4})
+
+        # users CANNOT initialize both values at the same time, because how
+        # do we know what to do with it then?
+        # Test case 1: Class instance
+        with self.assertRaises(ValueError):
+            solver = base.LegacySolverWrapper(
+                options={'max_iter': 6}, solver_options={'max_iter': 4}
+            )
+        # Test case 2: Passing to `solve`
+        solver = base.LegacySolverWrapper()
+        config = ConfigDict(implicit=True)
+        config.declare(
+            'solver_options',
+            ConfigDict(implicit=True, description="Options to pass to the solver."),
+        )
+        solver.config = config
+        with self.assertRaises(ValueError):
+            solver._map_config(solver_options={'max_iter': 4}, options={'max_iter': 6})
+
+    def test_map_results(self):
+        # Unclear how to test this
+        pass
+
+    def test_solution_handler(self):
+        # Unclear how to test this
+        pass
diff --git a/pyomo/contrib/solver/tests/unit/test_config.py b/pyomo/contrib/solver/tests/unit/test_config.py
new file mode 100644
index 00000000000..354cfd8a37a
--- /dev/null
+++ b/pyomo/contrib/solver/tests/unit/test_config.py
@@ -0,0 +1,120 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+from pyomo.common import unittest
+from pyomo.contrib.solver.config import (
+    SolverConfig,
+    BranchAndBoundConfig,
+    AutoUpdateConfig,
+    PersistentSolverConfig,
+)
+
+
+class TestSolverConfig(unittest.TestCase):
+    def test_interface_default_instantiation(self):
+        config = SolverConfig()
+        self.assertIsNone(config._description)
+        self.assertEqual(config._visibility, 0)
+        self.assertFalse(config.tee)
+        self.assertTrue(config.load_solutions)
+        self.assertTrue(config.raise_exception_on_nonoptimal_result)
+        self.assertFalse(config.symbolic_solver_labels)
+        self.assertIsNone(config.timer)
+        self.assertIsNone(config.threads)
+        self.assertIsNone(config.time_limit)
+
+    def test_interface_custom_instantiation(self):
+        config = SolverConfig(description="A description")
+        config.tee = True
+        self.assertTrue(config.tee)
+        self.assertEqual(config._description, "A description")
+        self.assertFalse(config.time_limit)
+        config.time_limit = 1.0
+        self.assertEqual(config.time_limit, 1.0)
+        self.assertIsInstance(config.time_limit, float)
+
+
+class TestBranchAndBoundConfig(unittest.TestCase):
+    def test_interface_default_instantiation(self):
+        config = BranchAndBoundConfig()
+        self.assertIsNone(config._description)
+        self.assertEqual(config._visibility, 0)
+        self.assertFalse(config.tee)
+        self.assertTrue(config.load_solutions)
+        self.assertFalse(config.symbolic_solver_labels)
+        self.assertIsNone(config.rel_gap)
+        self.assertIsNone(config.abs_gap)
+
+    def test_interface_custom_instantiation(self):
+        config = BranchAndBoundConfig(description="A description")
+        config.tee = True
+        self.assertTrue(config.tee)
+        self.assertEqual(config._description, "A description")
+        self.assertFalse(config.time_limit)
+        config.time_limit = 1.0
+        self.assertEqual(config.time_limit, 1.0)
+        self.assertIsInstance(config.time_limit, float)
+        config.rel_gap = 2.5
+        self.assertEqual(config.rel_gap, 2.5)
+
+
+class TestAutoUpdateConfig(unittest.TestCase):
+    def test_interface_default_instantiation(self):
+        config = AutoUpdateConfig()
+        self.assertTrue(config.check_for_new_or_removed_constraints)
+        self.assertTrue(config.check_for_new_or_removed_vars)
+        self.assertTrue(config.check_for_new_or_removed_params)
+        self.assertTrue(config.check_for_new_objective)
+        self.assertTrue(config.update_constraints)
+        self.assertTrue(config.update_vars)
+        self.assertTrue(config.update_named_expressions)
+        self.assertTrue(config.update_objective)
+        self.assertTrue(config.update_objective)
+        self.assertTrue(config.treat_fixed_vars_as_params)
+
+    def test_interface_custom_instantiation(self):
+        config = AutoUpdateConfig(description="A description")
+        config.check_for_new_objective = False
+        self.assertEqual(config._description, "A description")
+        self.assertTrue(config.check_for_new_or_removed_constraints)
+        self.assertFalse(config.check_for_new_objective)
+
+
+class TestPersistentSolverConfig(unittest.TestCase):
+    def test_interface_default_instantiation(self):
+        config = PersistentSolverConfig()
+        self.assertIsNone(config._description)
+        self.assertEqual(config._visibility, 0)
+        self.assertFalse(config.tee)
+        self.assertTrue(config.load_solutions)
+        self.assertTrue(config.raise_exception_on_nonoptimal_result)
+        self.assertFalse(config.symbolic_solver_labels)
+        self.assertIsNone(config.timer)
+        self.assertIsNone(config.threads)
+        self.assertIsNone(config.time_limit)
+        self.assertTrue(config.auto_updates.check_for_new_or_removed_constraints)
+        self.assertTrue(config.auto_updates.check_for_new_or_removed_vars)
+        self.assertTrue(config.auto_updates.check_for_new_or_removed_params)
+        self.assertTrue(config.auto_updates.check_for_new_objective)
+        self.assertTrue(config.auto_updates.update_constraints)
+        self.assertTrue(config.auto_updates.update_vars)
+        self.assertTrue(config.auto_updates.update_named_expressions)
+        self.assertTrue(config.auto_updates.update_objective)
+        self.assertTrue(config.auto_updates.update_objective)
+        self.assertTrue(config.auto_updates.treat_fixed_vars_as_params)
+
+    def test_interface_custom_instantiation(self):
+        config = PersistentSolverConfig(description="A description")
+        config.tee = True
+        config.auto_updates.check_for_new_objective = False
+        self.assertTrue(config.tee)
+        self.assertEqual(config._description, "A description")
+        self.assertFalse(config.auto_updates.check_for_new_objective)
diff --git a/pyomo/contrib/solver/tests/unit/test_ipopt.py b/pyomo/contrib/solver/tests/unit/test_ipopt.py
new file mode 100644
index 00000000000..cc459245506
--- /dev/null
+++ b/pyomo/contrib/solver/tests/unit/test_ipopt.py
@@ -0,0 +1,225 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import os
+
+from pyomo.common import unittest, Executable
+from pyomo.common.errors import DeveloperError
+from pyomo.common.tempfiles import TempfileManager
+from pyomo.repn.plugins.nl_writer import NLWriter
+from pyomo.contrib.solver import ipopt
+
+
+ipopt_available = ipopt.Ipopt().available()
+
+
+@unittest.skipIf(not ipopt_available, "The 'ipopt' command is not available")
+class TestIpoptSolverConfig(unittest.TestCase):
+    def test_default_instantiation(self):
+        config = ipopt.IpoptConfig()
+        # Should be inherited
+        self.assertIsNone(config._description)
+        self.assertEqual(config._visibility, 0)
+        self.assertFalse(config.tee)
+        self.assertTrue(config.load_solutions)
+        self.assertTrue(config.raise_exception_on_nonoptimal_result)
+        self.assertFalse(config.symbolic_solver_labels)
+        self.assertIsNone(config.timer)
+        self.assertIsNone(config.threads)
+        self.assertIsNone(config.time_limit)
+        # Unique to this object
+        self.assertIsInstance(config.executable, type(Executable('path')))
+        self.assertIsInstance(config.writer_config, type(NLWriter.CONFIG()))
+
+    def test_custom_instantiation(self):
+        config = ipopt.IpoptConfig(description="A description")
+        config.tee = True
+        self.assertTrue(config.tee)
+        self.assertEqual(config._description, "A description")
+        self.assertIsNone(config.time_limit)
+        # Default should be `ipopt`
+        self.assertIsNotNone(str(config.executable))
+        self.assertIn('ipopt', str(config.executable))
+        # Set to a totally bogus path
+        config.executable = Executable('/bogus/path')
+        self.assertIsNone(config.executable.executable)
+        self.assertFalse(config.executable.available())
+
+
+class TestIpoptSolutionLoader(unittest.TestCase):
+    def test_get_reduced_costs_error(self):
+        loader = ipopt.IpoptSolutionLoader(None, None)
+        with self.assertRaises(RuntimeError):
+            loader.get_reduced_costs()
+
+        # Set _nl_info to something completely bogus but is not None
+        class NLInfo:
+            pass
+
+        loader._nl_info = NLInfo()
+        loader._nl_info.eliminated_vars = [1, 2, 3]
+        with self.assertRaises(NotImplementedError):
+            loader.get_reduced_costs()
+        # Reset _nl_info so we can ensure we get an error
+        # when _sol_data is None
+        loader._nl_info.eliminated_vars = []
+        with self.assertRaises(DeveloperError):
+            loader.get_reduced_costs()
+
+
+@unittest.skipIf(not ipopt_available, "The 'ipopt' command is not available")
+class TestIpoptInterface(unittest.TestCase):
+    def test_class_member_list(self):
+        opt = ipopt.Ipopt()
+        expected_list = [
+            'Availability',
+            'CONFIG',
+            'config',
+            'available',
+            'is_persistent',
+            'solve',
+            'version',
+            'name',
+        ]
+        method_list = [method for method in dir(opt) if method.startswith('_') is False]
+        self.assertEqual(sorted(expected_list), sorted(method_list))
+
+    def test_default_instantiation(self):
+        opt = ipopt.Ipopt()
+        self.assertFalse(opt.is_persistent())
+        self.assertIsNotNone(opt.version())
+        self.assertEqual(opt.name, 'ipopt')
+        self.assertEqual(opt.CONFIG, opt.config)
+        self.assertTrue(opt.available())
+
+    def test_context_manager(self):
+        with ipopt.Ipopt() as opt:
+            self.assertFalse(opt.is_persistent())
+            self.assertIsNotNone(opt.version())
+            self.assertEqual(opt.name, 'ipopt')
+            self.assertEqual(opt.CONFIG, opt.config)
+            self.assertTrue(opt.available())
+
+    def test_available_cache(self):
+        opt = ipopt.Ipopt()
+        opt.available()
+        self.assertTrue(opt._available_cache[1])
+        self.assertIsNotNone(opt._available_cache[0])
+        # Now we will try with a custom config that has a fake path
+        config = ipopt.IpoptConfig()
+        config.executable = Executable('/a/bogus/path')
+        opt.available(config=config)
+        self.assertFalse(opt._available_cache[1])
+        self.assertIsNone(opt._available_cache[0])
+
+    def test_version_cache(self):
+        opt = ipopt.Ipopt()
+        opt.version()
+        self.assertIsNotNone(opt._version_cache[0])
+        self.assertIsNotNone(opt._version_cache[1])
+        # Now we will try with a custom config that has a fake path
+        config = ipopt.IpoptConfig()
+        config.executable = Executable('/a/bogus/path')
+        opt.version(config=config)
+        self.assertIsNone(opt._version_cache[0])
+        self.assertIsNone(opt._version_cache[1])
+
+    def test_write_options_file(self):
+        # If we have no options, we should get false back
+        opt = ipopt.Ipopt()
+        result = opt._write_options_file('fakename', None)
+        self.assertFalse(result)
+        # Pass it some options that ARE on the command line
+        opt = ipopt.Ipopt(solver_options={'max_iter': 4})
+        result = opt._write_options_file('myfile', opt.config.solver_options)
+        self.assertFalse(result)
+        self.assertFalse(os.path.isfile('myfile.opt'))
+        # Now we are going to actually pass it some options that are NOT on
+        # the command line
+        opt = ipopt.Ipopt(solver_options={'custom_option': 4})
+        with TempfileManager.new_context() as temp:
+            dname = temp.mkdtemp()
+            if not os.path.exists(dname):
+                os.mkdir(dname)
+            filename = os.path.join(dname, 'myfile')
+            result = opt._write_options_file(filename, opt.config.solver_options)
+            self.assertTrue(result)
+            self.assertTrue(os.path.isfile(filename + '.opt'))
+        # Make sure all options are writing to the file
+        opt = ipopt.Ipopt(solver_options={'custom_option_1': 4, 'custom_option_2': 3})
+        with TempfileManager.new_context() as temp:
+            dname = temp.mkdtemp()
+            if not os.path.exists(dname):
+                os.mkdir(dname)
+            filename = os.path.join(dname, 'myfile')
+            result = opt._write_options_file(filename, opt.config.solver_options)
+            self.assertTrue(result)
+            self.assertTrue(os.path.isfile(filename + '.opt'))
+            with open(filename + '.opt', 'r') as f:
+                data = f.readlines()
+                self.assertEqual(len(data), len(list(opt.config.solver_options.keys())))
+
+    def test_create_command_line(self):
+        opt = ipopt.Ipopt()
+        # No custom options, no file created. Plain and simple.
+        result = opt._create_command_line('myfile', opt.config, False)
+        self.assertEqual(result, [str(opt.config.executable), 'myfile.nl', '-AMPL'])
+        # Custom command line options
+        opt = ipopt.Ipopt(solver_options={'max_iter': 4})
+        result = opt._create_command_line('myfile', opt.config, False)
+        self.assertEqual(
+            result, [str(opt.config.executable), 'myfile.nl', '-AMPL', 'max_iter=4']
+        )
+        # Let's see if we correctly parse config.time_limit
+        opt = ipopt.Ipopt(solver_options={'max_iter': 4}, time_limit=10)
+        result = opt._create_command_line('myfile', opt.config, False)
+        self.assertEqual(
+            result,
+            [
+                str(opt.config.executable),
+                'myfile.nl',
+                '-AMPL',
+                'max_iter=4',
+                'max_cpu_time=10.0',
+            ],
+        )
+        # Now let's do multiple command line options
+        opt = ipopt.Ipopt(solver_options={'max_iter': 4, 'max_cpu_time': 10})
+        result = opt._create_command_line('myfile', opt.config, False)
+        self.assertEqual(
+            result,
+            [
+                str(opt.config.executable),
+                'myfile.nl',
+                '-AMPL',
+                'max_cpu_time=10',
+                'max_iter=4',
+            ],
+        )
+        # Let's now include if we "have" an options file
+        result = opt._create_command_line('myfile', opt.config, True)
+        self.assertEqual(
+            result,
+            [
+                str(opt.config.executable),
+                'myfile.nl',
+                '-AMPL',
+                'option_file_name=myfile.opt',
+                'max_cpu_time=10',
+                'max_iter=4',
+            ],
+        )
+        # Finally, let's make sure it errors if someone tries to pass option_file_name
+        opt = ipopt.Ipopt(
+            solver_options={'max_iter': 4, 'option_file_name': 'myfile.opt'}
+        )
+        with self.assertRaises(ValueError):
+            result = opt._create_command_line('myfile', opt.config, False)
diff --git a/pyomo/contrib/solver/tests/unit/test_results.py b/pyomo/contrib/solver/tests/unit/test_results.py
new file mode 100644
index 00000000000..a15c9b87253
--- /dev/null
+++ b/pyomo/contrib/solver/tests/unit/test_results.py
@@ -0,0 +1,261 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+from io import StringIO
+from typing import Sequence, Dict, Optional, Mapping, MutableMapping
+
+
+from pyomo.common import unittest
+from pyomo.common.config import ConfigDict
+from pyomo.core.base.constraint import ConstraintData
+from pyomo.core.base.var import VarData
+from pyomo.common.collections import ComponentMap
+from pyomo.contrib.solver import results
+from pyomo.contrib.solver import solution
+import pyomo.environ as pyo
+from pyomo.core.base.var import Var
+
+
+class SolutionLoaderExample(solution.SolutionLoaderBase):
+    """
+    This is an example instantiation of a SolutionLoader that is used for
+    testing generated results.
+    """
+
+    def __init__(
+        self,
+        primals: Optional[MutableMapping],
+        duals: Optional[MutableMapping],
+        reduced_costs: Optional[MutableMapping],
+    ):
+        """
+        Parameters
+        ----------
+        primals: dict
+            maps id(Var) to (var, value)
+        duals: dict
+            maps Constraint to dual value
+        reduced_costs: dict
+            maps id(Var) to (var, reduced_cost)
+        """
+        self._primals = primals
+        self._duals = duals
+        self._reduced_costs = reduced_costs
+
+    def get_primals(
+        self, vars_to_load: Optional[Sequence[VarData]] = None
+    ) -> Mapping[VarData, float]:
+        if self._primals is None:
+            raise RuntimeError(
+                'Solution loader does not currently have a valid solution. Please '
+                'check the termination condition.'
+            )
+        if vars_to_load is None:
+            return ComponentMap(self._primals.values())
+        else:
+            primals = ComponentMap()
+            for v in vars_to_load:
+                primals[v] = self._primals[id(v)][1]
+            return primals
+
+    def get_duals(
+        self, cons_to_load: Optional[Sequence[ConstraintData]] = None
+    ) -> Dict[ConstraintData, float]:
+        if self._duals is None:
+            raise RuntimeError(
+                'Solution loader does not currently have valid duals. Please '
+                'check the termination condition and ensure the solver returns duals '
+                'for the given problem type.'
+            )
+        if cons_to_load is None:
+            duals = dict(self._duals)
+        else:
+            duals = {}
+            for c in cons_to_load:
+                duals[c] = self._duals[c]
+        return duals
+
+    def get_reduced_costs(
+        self, vars_to_load: Optional[Sequence[VarData]] = None
+    ) -> Mapping[VarData, float]:
+        if self._reduced_costs is None:
+            raise RuntimeError(
+                'Solution loader does not currently have valid reduced costs. Please '
+                'check the termination condition and ensure the solver returns reduced '
+                'costs for the given problem type.'
+            )
+        if vars_to_load is None:
+            rc = ComponentMap(self._reduced_costs.values())
+        else:
+            rc = ComponentMap()
+            for v in vars_to_load:
+                rc[v] = self._reduced_costs[id(v)][1]
+        return rc
+
+
+class TestTerminationCondition(unittest.TestCase):
+    def test_member_list(self):
+        member_list = results.TerminationCondition._member_names_
+        expected_list = [
+            'unknown',
+            'convergenceCriteriaSatisfied',
+            'maxTimeLimit',
+            'iterationLimit',
+            'objectiveLimit',
+            'minStepLength',
+            'unbounded',
+            'provenInfeasible',
+            'locallyInfeasible',
+            'infeasibleOrUnbounded',
+            'error',
+            'interrupted',
+            'licensingProblems',
+        ]
+        self.assertEqual(member_list.sort(), expected_list.sort())
+
+    def test_codes(self):
+        self.assertEqual(results.TerminationCondition.unknown.value, 42)
+        self.assertEqual(
+            results.TerminationCondition.convergenceCriteriaSatisfied.value, 0
+        )
+        self.assertEqual(results.TerminationCondition.maxTimeLimit.value, 1)
+        self.assertEqual(results.TerminationCondition.iterationLimit.value, 2)
+        self.assertEqual(results.TerminationCondition.objectiveLimit.value, 3)
+        self.assertEqual(results.TerminationCondition.minStepLength.value, 4)
+        self.assertEqual(results.TerminationCondition.unbounded.value, 5)
+        self.assertEqual(results.TerminationCondition.provenInfeasible.value, 6)
+        self.assertEqual(results.TerminationCondition.locallyInfeasible.value, 7)
+        self.assertEqual(results.TerminationCondition.infeasibleOrUnbounded.value, 8)
+        self.assertEqual(results.TerminationCondition.error.value, 9)
+        self.assertEqual(results.TerminationCondition.interrupted.value, 10)
+        self.assertEqual(results.TerminationCondition.licensingProblems.value, 11)
+
+
+class TestSolutionStatus(unittest.TestCase):
+    def test_member_list(self):
+        member_list = results.SolutionStatus._member_names_
+        expected_list = ['noSolution', 'infeasible', 'feasible', 'optimal']
+        self.assertEqual(member_list, expected_list)
+
+    def test_codes(self):
+        self.assertEqual(results.SolutionStatus.noSolution.value, 0)
+        self.assertEqual(results.SolutionStatus.infeasible.value, 10)
+        self.assertEqual(results.SolutionStatus.feasible.value, 20)
+        self.assertEqual(results.SolutionStatus.optimal.value, 30)
+
+
+class TestResults(unittest.TestCase):
+    def test_member_list(self):
+        res = results.Results()
+        expected_declared = {
+            'extra_info',
+            'incumbent_objective',
+            'iteration_count',
+            'objective_bound',
+            'solution_loader',
+            'solution_status',
+            'solver_name',
+            'solver_version',
+            'termination_condition',
+            'timing_info',
+            'solver_log',
+            'solver_configuration',
+        }
+        actual_declared = res._declared
+        self.assertEqual(expected_declared, actual_declared)
+
+    def test_default_initialization(self):
+        res = results.Results()
+        self.assertIsNone(res.solution_loader)
+        self.assertIsNone(res.incumbent_objective)
+        self.assertIsNone(res.objective_bound)
+        self.assertEqual(
+            res.termination_condition, results.TerminationCondition.unknown
+        )
+        self.assertEqual(res.solution_status, results.SolutionStatus.noSolution)
+        self.assertIsNone(res.solver_name)
+        self.assertIsNone(res.solver_version)
+        self.assertIsNone(res.iteration_count)
+        self.assertIsInstance(res.timing_info, ConfigDict)
+        self.assertIsInstance(res.extra_info, ConfigDict)
+        self.assertIsNone(res.timing_info.start_timestamp)
+        self.assertIsNone(res.timing_info.wall_time)
+
+    def test_display(self):
+        res = results.Results()
+        stream = StringIO()
+        res.display(ostream=stream)
+        expected_print = """solution_loader: None
+termination_condition: TerminationCondition.unknown
+solution_status: SolutionStatus.noSolution
+incumbent_objective: None
+objective_bound: None
+solver_name: None
+solver_version: None
+iteration_count: None
+timing_info:
+  start_timestamp: None
+  wall_time: None
+extra_info:
+"""
+        out = stream.getvalue()
+        if 'null' in out:
+            out = out.replace('null', 'None')
+        self.assertEqual(expected_print, out)
+
+    def test_generated_results(self):
+        m = pyo.ConcreteModel()
+        m.x = Var()
+        m.y = Var()
+        m.c1 = pyo.Constraint(expr=m.x == 1)
+        m.c2 = pyo.Constraint(expr=m.y == 2)
+
+        primals = {}
+        primals[id(m.x)] = (m.x, 1)
+        primals[id(m.y)] = (m.y, 2)
+        duals = {}
+        duals[m.c1] = 3
+        duals[m.c2] = 4
+        rc = {}
+        rc[id(m.x)] = (m.x, 5)
+        rc[id(m.y)] = (m.y, 6)
+
+        res = results.Results()
+        res.solution_loader = SolutionLoaderExample(
+            primals=primals, duals=duals, reduced_costs=rc
+        )
+
+        res.solution_loader.load_vars()
+        self.assertAlmostEqual(m.x.value, 1)
+        self.assertAlmostEqual(m.y.value, 2)
+
+        m.x.value = None
+        m.y.value = None
+
+        res.solution_loader.load_vars([m.y])
+        self.assertIsNone(m.x.value)
+        self.assertAlmostEqual(m.y.value, 2)
+
+        duals2 = res.solution_loader.get_duals()
+        self.assertAlmostEqual(duals[m.c1], duals2[m.c1])
+        self.assertAlmostEqual(duals[m.c2], duals2[m.c2])
+
+        duals2 = res.solution_loader.get_duals([m.c2])
+        self.assertNotIn(m.c1, duals2)
+        self.assertAlmostEqual(duals[m.c2], duals2[m.c2])
+
+        rc2 = res.solution_loader.get_reduced_costs()
+        self.assertAlmostEqual(rc[id(m.x)][1], rc2[m.x])
+        self.assertAlmostEqual(rc[id(m.y)][1], rc2[m.y])
+
+        rc2 = res.solution_loader.get_reduced_costs([m.y])
+        self.assertNotIn(m.x, rc2)
+        self.assertAlmostEqual(rc[id(m.y)][1], rc2[m.y])
diff --git a/pyomo/contrib/solver/tests/unit/test_sol_reader.py b/pyomo/contrib/solver/tests/unit/test_sol_reader.py
new file mode 100644
index 00000000000..d5602945e07
--- /dev/null
+++ b/pyomo/contrib/solver/tests/unit/test_sol_reader.py
@@ -0,0 +1,51 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+from pyomo.common import unittest
+from pyomo.common.fileutils import this_file_dir
+from pyomo.common.tempfiles import TempfileManager
+from pyomo.contrib.solver.sol_reader import parse_sol_file, SolFileData
+
+currdir = this_file_dir()
+
+
+class TestSolFileData(unittest.TestCase):
+    def test_default_instantiation(self):
+        instance = SolFileData()
+        self.assertIsInstance(instance.primals, list)
+        self.assertIsInstance(instance.duals, list)
+        self.assertIsInstance(instance.var_suffixes, dict)
+        self.assertIsInstance(instance.con_suffixes, dict)
+        self.assertIsInstance(instance.obj_suffixes, dict)
+        self.assertIsInstance(instance.problem_suffixes, dict)
+        self.assertIsInstance(instance.other, list)
+
+
+class TestSolParser(unittest.TestCase):
+    # I am not sure how to write these tests best since the sol parser requires
+    # not only a file but also the nl_info and results objects.
+    def setUp(self):
+        TempfileManager.push()
+
+    def tearDown(self):
+        TempfileManager.pop(remove=True)
+
+    def test_default_behavior(self):
+        pass
+
+    def test_custom_behavior(self):
+        pass
+
+    def test_infeasible1(self):
+        pass
+
+    def test_infeasible2(self):
+        pass
diff --git a/pyomo/contrib/solver/tests/unit/test_solution.py b/pyomo/contrib/solver/tests/unit/test_solution.py
new file mode 100644
index 00000000000..a5ee8a9e391
--- /dev/null
+++ b/pyomo/contrib/solver/tests/unit/test_solution.py
@@ -0,0 +1,88 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+from pyomo.common import unittest
+from pyomo.contrib.solver.solution import SolutionLoaderBase, PersistentSolutionLoader
+
+
+class TestSolutionLoaderBase(unittest.TestCase):
+    def test_abstract_member_list(self):
+        expected_list = ['get_primals']
+        member_list = list(SolutionLoaderBase.__abstractmethods__)
+        self.assertEqual(sorted(expected_list), sorted(member_list))
+
+    def test_member_list(self):
+        expected_list = ['load_vars', 'get_primals', 'get_duals', 'get_reduced_costs']
+        method_list = [
+            method
+            for method in dir(SolutionLoaderBase)
+            if method.startswith('_') is False
+        ]
+        self.assertEqual(sorted(expected_list), sorted(method_list))
+
+    @unittest.mock.patch.multiple(SolutionLoaderBase, __abstractmethods__=set())
+    def test_solution_loader_base(self):
+        self.instance = SolutionLoaderBase()
+        self.assertEqual(self.instance.get_primals(), None)
+        with self.assertRaises(NotImplementedError):
+            self.instance.get_duals()
+        with self.assertRaises(NotImplementedError):
+            self.instance.get_reduced_costs()
+
+
+class TestSolSolutionLoader(unittest.TestCase):
+    # I am currently unsure how to test this further because it relies heavily on
+    # SolFileData and NLWriterInfo
+    def test_member_list(self):
+        expected_list = ['load_vars', 'get_primals', 'get_duals', 'get_reduced_costs']
+        method_list = [
+            method
+            for method in dir(SolutionLoaderBase)
+            if method.startswith('_') is False
+        ]
+        self.assertEqual(sorted(expected_list), sorted(method_list))
+
+
+class TestPersistentSolutionLoader(unittest.TestCase):
+    def test_abstract_member_list(self):
+        # We expect no abstract members at this point because it's a real-life
+        # instantiation of SolutionLoaderBase
+        member_list = list(PersistentSolutionLoader('ipopt').__abstractmethods__)
+        self.assertEqual(member_list, [])
+
+    def test_member_list(self):
+        expected_list = [
+            'load_vars',
+            'get_primals',
+            'get_duals',
+            'get_reduced_costs',
+            'invalidate',
+        ]
+        method_list = [
+            method
+            for method in dir(PersistentSolutionLoader)
+            if method.startswith('_') is False
+        ]
+        self.assertEqual(sorted(expected_list), sorted(method_list))
+
+    def test_default_initialization(self):
+        # Realistically, a solver object should be passed into this.
+        # However, it works with a string. It'll just error loudly if you
+        # try to run get_primals, etc.
+        self.instance = PersistentSolutionLoader('ipopt')
+        self.assertTrue(self.instance._valid)
+        self.assertEqual(self.instance._solver, 'ipopt')
+
+    def test_invalid(self):
+        self.instance = PersistentSolutionLoader('ipopt')
+        self.instance.invalidate()
+        with self.assertRaises(RuntimeError):
+            self.instance.get_primals()
diff --git a/pyomo/contrib/solver/tests/unit/test_util.py b/pyomo/contrib/solver/tests/unit/test_util.py
new file mode 100644
index 00000000000..f2e8ee707f4
--- /dev/null
+++ b/pyomo/contrib/solver/tests/unit/test_util.py
@@ -0,0 +1,142 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+from pyomo.common import unittest
+import pyomo.environ as pyo
+from pyomo.contrib.solver.util import (
+    collect_vars_and_named_exprs,
+    get_objective,
+    check_optimal_termination,
+    assert_optimal_termination,
+    SolverStatus,
+    LegacyTerminationCondition,
+)
+from pyomo.contrib.solver.results import Results, SolutionStatus, TerminationCondition
+from typing import Callable
+from pyomo.common.gsl import find_GSL
+from pyomo.opt.results import SolverResults
+
+
+class TestGenericUtils(unittest.TestCase):
+    def basics_helper(self, collector: Callable, *args):
+        m = pyo.ConcreteModel()
+        m.x = pyo.Var()
+        m.y = pyo.Var()
+        m.z = pyo.Var()
+        m.E = pyo.Expression(expr=2 * m.z + 1)
+        m.y.fix(3)
+        e = m.x * m.y + m.x * m.E
+        named_exprs, var_list, fixed_vars, external_funcs = collector(e, *args)
+        self.assertEqual([m.E], named_exprs)
+        self.assertEqual([m.x, m.y, m.z], var_list)
+        self.assertEqual([m.y], fixed_vars)
+        self.assertEqual([], external_funcs)
+
+    def test_collect_vars_basics(self):
+        self.basics_helper(collect_vars_and_named_exprs)
+
+    def external_func_helper(self, collector: Callable, *args):
+        DLL = find_GSL()
+        if not DLL:
+            self.skipTest('Could not find amplgsl.dll library')
+
+        m = pyo.ConcreteModel()
+        m.x = pyo.Var()
+        m.y = pyo.Var()
+        m.z = pyo.Var()
+        m.hypot = pyo.ExternalFunction(library=DLL, function='gsl_hypot')
+        func = m.hypot(m.x, m.x * m.y)
+        m.E = pyo.Expression(expr=2 * func)
+        m.y.fix(3)
+        e = m.z + m.x * m.E
+        named_exprs, var_list, fixed_vars, external_funcs = collector(e, *args)
+        self.assertEqual([m.E], named_exprs)
+        self.assertEqual([m.z, m.x, m.y], var_list)
+        self.assertEqual([m.y], fixed_vars)
+        self.assertEqual([func], external_funcs)
+
+    def test_collect_vars_external(self):
+        self.external_func_helper(collect_vars_and_named_exprs)
+
+    def simple_model(self):
+        model = pyo.ConcreteModel()
+        model.x = pyo.Var([1, 2], domain=pyo.NonNegativeReals)
+        model.OBJ = pyo.Objective(expr=2 * model.x[1] + 3 * model.x[2])
+        model.Constraint1 = pyo.Constraint(expr=3 * model.x[1] + 4 * model.x[2] >= 1)
+        return model
+
+    def test_get_objective_success(self):
+        model = self.simple_model()
+        self.assertEqual(model.OBJ, get_objective(model))
+
+    def test_get_objective_raise(self):
+        model = self.simple_model()
+        model.OBJ2 = pyo.Objective(expr=model.x[1] - 4 * model.x[2])
+        with self.assertRaises(ValueError):
+            get_objective(model)
+
+    def test_check_optimal_termination_new_interface(self):
+        results = Results()
+        results.solution_status = SolutionStatus.optimal
+        results.termination_condition = (
+            TerminationCondition.convergenceCriteriaSatisfied
+        )
+        # Both items satisfied
+        self.assertTrue(check_optimal_termination(results))
+        # Termination condition not satisfied
+        results.termination_condition = TerminationCondition.iterationLimit
+        self.assertFalse(check_optimal_termination(results))
+        # Both not satisfied
+        results.solution_status = SolutionStatus.noSolution
+        self.assertFalse(check_optimal_termination(results))
+
+    def test_check_optimal_termination_condition_legacy_interface(self):
+        results = SolverResults()
+        results.solver.status = SolverStatus.ok
+        results.solver.termination_condition = LegacyTerminationCondition.optimal
+        # Both items satisfied
+        self.assertTrue(check_optimal_termination(results))
+        # Termination condition not satisfied
+        results.solver.termination_condition = LegacyTerminationCondition.unknown
+        self.assertFalse(check_optimal_termination(results))
+        # Both not satisfied
+        results.solver.termination_condition = SolverStatus.aborted
+        self.assertFalse(check_optimal_termination(results))
+
+    def test_assert_optimal_termination_new_interface(self):
+        results = Results()
+        results.solution_status = SolutionStatus.optimal
+        results.termination_condition = (
+            TerminationCondition.convergenceCriteriaSatisfied
+        )
+        assert_optimal_termination(results)
+        # Termination condition not satisfied
+        results.termination_condition = TerminationCondition.iterationLimit
+        with self.assertRaises(RuntimeError):
+            assert_optimal_termination(results)
+        # Both not satisfied
+        results.solution_status = SolutionStatus.noSolution
+        with self.assertRaises(RuntimeError):
+            assert_optimal_termination(results)
+
+    def test_assert_optimal_termination_legacy_interface(self):
+        results = SolverResults()
+        results.solver.status = SolverStatus.ok
+        results.solver.termination_condition = LegacyTerminationCondition.optimal
+        assert_optimal_termination(results)
+        # Termination condition not satisfied
+        results.solver.termination_condition = LegacyTerminationCondition.unknown
+        with self.assertRaises(RuntimeError):
+            assert_optimal_termination(results)
+        # Both not satisfied
+        results.solver.termination_condition = SolverStatus.aborted
+        with self.assertRaises(RuntimeError):
+            assert_optimal_termination(results)
diff --git a/pyomo/contrib/solver/util.py b/pyomo/contrib/solver/util.py
new file mode 100644
index 00000000000..c6bbfbd22ad
--- /dev/null
+++ b/pyomo/contrib/solver/util.py
@@ -0,0 +1,143 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+from pyomo.core.expr.visitor import ExpressionValueVisitor, nonpyomo_leaf_types
+import pyomo.core.expr as EXPR
+from pyomo.core.base.objective import Objective
+from pyomo.opt.results.solver import (
+    SolverStatus,
+    TerminationCondition as LegacyTerminationCondition,
+)
+
+
+from pyomo.contrib.solver.results import TerminationCondition, SolutionStatus
+
+
+def get_objective(block):
+    """
+    Get current active objective on a block. If there is more than one active,
+    return an error.
+    """
+    obj = None
+    for o in block.component_data_objects(
+        Objective, descend_into=True, active=True, sort=True
+    ):
+        if obj is not None:
+            raise ValueError('Multiple active objectives found')
+        obj = o
+    return obj
+
+
+def check_optimal_termination(results):
+    """
+    This function returns True if the termination condition for the solver
+    is 'optimal'.
+
+    Parameters
+    ----------
+    results : Pyomo Results object returned from solver.solve
+
+    Returns
+    -------
+    `bool`
+    """
+    if hasattr(results, 'solution_status'):
+        if results.solution_status == SolutionStatus.optimal and (
+            results.termination_condition
+            == TerminationCondition.convergenceCriteriaSatisfied
+        ):
+            return True
+    else:
+        if results.solver.status == SolverStatus.ok and (
+            results.solver.termination_condition == LegacyTerminationCondition.optimal
+            or results.solver.termination_condition
+            == LegacyTerminationCondition.locallyOptimal
+            or results.solver.termination_condition
+            == LegacyTerminationCondition.globallyOptimal
+        ):
+            return True
+    return False
+
+
+def assert_optimal_termination(results):
+    """
+    This function checks if the termination condition for the solver
+    is 'optimal', 'locallyOptimal', or 'globallyOptimal', and the status is 'ok'
+    and it raises a RuntimeError exception if this is not true.
+
+    Parameters
+    ----------
+    results : Pyomo Results object returned from solver.solve
+    """
+    if not check_optimal_termination(results):
+        if hasattr(results, 'solution_status'):
+            msg = (
+                'Solver failed to return an optimal solution. '
+                'Solution status: {}, Termination condition: {}'.format(
+                    results.solution_status, results.termination_condition
+                )
+            )
+        else:
+            msg = (
+                'Solver failed to return an optimal solution. '
+                'Solver status: {}, Termination condition: {}'.format(
+                    results.solver.status, results.solver.termination_condition
+                )
+            )
+        raise RuntimeError(msg)
+
+
+class _VarAndNamedExprCollector(ExpressionValueVisitor):
+    def __init__(self):
+        self.named_expressions = {}
+        self.variables = {}
+        self.fixed_vars = {}
+        self._external_functions = {}
+
+    def visit(self, node, values):
+        pass
+
+    def visiting_potential_leaf(self, node):
+        if type(node) in nonpyomo_leaf_types:
+            return True, None
+
+        if node.is_variable_type():
+            self.variables[id(node)] = node
+            if node.is_fixed():
+                self.fixed_vars[id(node)] = node
+            return True, None
+
+        if node.is_named_expression_type():
+            self.named_expressions[id(node)] = node
+            return False, None
+
+        if type(node) is EXPR.ExternalFunctionExpression:
+            self._external_functions[id(node)] = node
+            return False, None
+
+        if node.is_expression_type():
+            return False, None
+
+        return True, None
+
+
+_visitor = _VarAndNamedExprCollector()
+
+
+def collect_vars_and_named_exprs(expr):
+    _visitor.__init__()
+    _visitor.dfs_postorder_stack(expr)
+    return (
+        list(_visitor.named_expressions.values()),
+        list(_visitor.variables.values()),
+        list(_visitor.fixed_vars.values()),
+        list(_visitor._external_functions.values()),
+    )
diff --git a/pyomo/contrib/trustregion/TRF.py b/pyomo/contrib/trustregion/TRF.py
index 45e60df7658..ea3a8c746a4 100644
--- a/pyomo/contrib/trustregion/TRF.py
+++ b/pyomo/contrib/trustregion/TRF.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -35,7 +35,7 @@
 
 logger = logging.getLogger('pyomo.contrib.trustregion')
 
-__version__ = '0.2.0'
+__version__ = (0, 2, 0)
 
 
 def trust_region_method(model, decision_variables, ext_fcn_surrogate_map_rule, config):
diff --git a/pyomo/contrib/trustregion/__init__.py b/pyomo/contrib/trustregion/__init__.py
index 62ba0892686..38b30839be3 100644
--- a/pyomo/contrib/trustregion/__init__.py
+++ b/pyomo/contrib/trustregion/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/trustregion/examples/__init__.py b/pyomo/contrib/trustregion/examples/__init__.py
index 62ba0892686..38b30839be3 100644
--- a/pyomo/contrib/trustregion/examples/__init__.py
+++ b/pyomo/contrib/trustregion/examples/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/trustregion/examples/example1.py b/pyomo/contrib/trustregion/examples/example1.py
index 19965ff1cb2..66df26d143f 100755
--- a/pyomo/contrib/trustregion/examples/example1.py
+++ b/pyomo/contrib/trustregion/examples/example1.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/trustregion/examples/example2.py b/pyomo/contrib/trustregion/examples/example2.py
index 0c506eb6891..ad648855410 100644
--- a/pyomo/contrib/trustregion/examples/example2.py
+++ b/pyomo/contrib/trustregion/examples/example2.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/trustregion/filter.py b/pyomo/contrib/trustregion/filter.py
index 2f0b20ee8f8..7e647a7f0c5 100644
--- a/pyomo/contrib/trustregion/filter.py
+++ b/pyomo/contrib/trustregion/filter.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/trustregion/interface.py b/pyomo/contrib/trustregion/interface.py
index f68f2fdb308..b459e7cfa17 100644
--- a/pyomo/contrib/trustregion/interface.py
+++ b/pyomo/contrib/trustregion/interface.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/trustregion/plugins.py b/pyomo/contrib/trustregion/plugins.py
index 59a11986f3c..d4ed22b9d2f 100644
--- a/pyomo/contrib/trustregion/plugins.py
+++ b/pyomo/contrib/trustregion/plugins.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/trustregion/tests/__init__.py b/pyomo/contrib/trustregion/tests/__init__.py
index 62ba0892686..38b30839be3 100644
--- a/pyomo/contrib/trustregion/tests/__init__.py
+++ b/pyomo/contrib/trustregion/tests/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/trustregion/tests/test_TRF.py b/pyomo/contrib/trustregion/tests/test_TRF.py
index e14a784b4af..e2b2b2b64ad 100644
--- a/pyomo/contrib/trustregion/tests/test_TRF.py
+++ b/pyomo/contrib/trustregion/tests/test_TRF.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/trustregion/tests/test_examples.py b/pyomo/contrib/trustregion/tests/test_examples.py
index a954b0851c7..5451cca5961 100644
--- a/pyomo/contrib/trustregion/tests/test_examples.py
+++ b/pyomo/contrib/trustregion/tests/test_examples.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/trustregion/tests/test_filter.py b/pyomo/contrib/trustregion/tests/test_filter.py
index 1b89d8d5cd1..18e833685f8 100644
--- a/pyomo/contrib/trustregion/tests/test_filter.py
+++ b/pyomo/contrib/trustregion/tests/test_filter.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/trustregion/tests/test_interface.py b/pyomo/contrib/trustregion/tests/test_interface.py
index a7e6457a5ca..0922ccf950b 100644
--- a/pyomo/contrib/trustregion/tests/test_interface.py
+++ b/pyomo/contrib/trustregion/tests/test_interface.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -33,7 +33,7 @@
     cos,
     SolverFactory,
 )
-from pyomo.core.base.var import _GeneralVarData
+from pyomo.core.base.var import VarData
 from pyomo.core.expr.numeric_expr import ExternalFunctionExpression
 from pyomo.core.expr.visitor import identify_variables
 from pyomo.contrib.trustregion.interface import TRFInterface
@@ -158,7 +158,7 @@ def test_replaceExternalFunctionsWithVariables(self):
             self.assertIsInstance(k, ExternalFunctionExpression)
             self.assertIn(str(self.interface.model.x[0]), str(k))
             self.assertIn(str(self.interface.model.x[1]), str(k))
-            self.assertIsInstance(i, _GeneralVarData)
+            self.assertIsInstance(i, VarData)
             self.assertEqual(i, self.interface.data.ef_outputs[1])
         for i, k in self.interface.data.basis_expressions.items():
             self.assertEqual(k, 0)
diff --git a/pyomo/contrib/trustregion/tests/test_util.py b/pyomo/contrib/trustregion/tests/test_util.py
index 3054c2c2bd5..bdc91744e61 100644
--- a/pyomo/contrib/trustregion/tests/test_util.py
+++ b/pyomo/contrib/trustregion/tests/test_util.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/trustregion/util.py b/pyomo/contrib/trustregion/util.py
index f27420a2bee..ff3f218fc27 100644
--- a/pyomo/contrib/trustregion/util.py
+++ b/pyomo/contrib/trustregion/util.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/viewer/README.md b/pyomo/contrib/viewer/README.md
index cfc50b54ce2..93d773e3829 100644
--- a/pyomo/contrib/viewer/README.md
+++ b/pyomo/contrib/viewer/README.md
@@ -42,6 +42,24 @@ ui = get_mainwindow(model=model)
 # Do model things, the viewer will stay in sync with the Pyomo model
 ```
 
+If you are working in Jupyter notebook, Jupyter qtconsole, or other Jupyter-
+based IDEs, and your model is in the __main__ namespace (this is the usual case),
+you can specify the model by its variable name as below.  The advantage of this
+is that if you replace the model with a new model having the same variable name,
+the UI will automatically update without having to manually reset the model pointer.
+
+```python
+%gui qt  #Enables IPython's GUI event loop integration.
+# Execute the above in its own cell and wait for it to finish before moving on.
+from pyomo.contrib.viewer.ui import get_mainwindow
+import pyomo.environ as pyo
+
+model = pyo.ConcreteModel() # could import an existing model here
+ui = get_mainwindow(model_var_name_in_main="model")
+
+# Do model things, the viewer will stay in sync with the Pyomo model
+```
+
 **Note:** the ```%gui qt``` cell must be executed in its own cell and execution
 must complete before running any other cells (you can't use "run all").
 
diff --git a/pyomo/contrib/viewer/__init__.py b/pyomo/contrib/viewer/__init__.py
index 8b137891791..a4a626013c4 100644
--- a/pyomo/contrib/viewer/__init__.py
+++ b/pyomo/contrib/viewer/__init__.py
@@ -1 +1,10 @@
-
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/viewer/model_browser.py b/pyomo/contrib/viewer/model_browser.py
index 8379518a4cf..91dc946c55d 100644
--- a/pyomo/contrib/viewer/model_browser.py
+++ b/pyomo/contrib/viewer/model_browser.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -33,7 +33,7 @@
 import pyomo.contrib.viewer.qt as myqt
 from pyomo.contrib.viewer.report import value_no_exception, get_residual
 
-from pyomo.core.base.param import _ParamData
+from pyomo.core.base.param import ParamData
 from pyomo.environ import (
     Block,
     BooleanVar,
@@ -243,7 +243,7 @@ def _get_expr_callback(self):
             return None
 
     def _get_value_callback(self):
-        if isinstance(self.data, _ParamData):
+        if isinstance(self.data, ParamData):
             v = value_no_exception(self.data, div0="divide_by_0")
             # Check the param value for numpy float and int, sometimes numpy
             # values can sneak in especially if you set parameters from data
@@ -295,7 +295,7 @@ def _get_residual_callback(self):
     def _get_units_callback(self):
         if isinstance(self.data, (Var, Var._ComponentDataClass)):
             return str(units.get_units(self.data))
-        if isinstance(self.data, (Param, _ParamData)):
+        if isinstance(self.data, (Param, ParamData)):
             return str(units.get_units(self.data))
         return self._cache_units
 
@@ -320,7 +320,7 @@ def _set_value_callback(self, val):
                     o.value = val
             except:
                 return
-        elif isinstance(self.data, _ParamData):
+        elif isinstance(self.data, ParamData):
             if not self.data.parent_component().mutable:
                 return
             try:
diff --git a/pyomo/contrib/viewer/model_select.py b/pyomo/contrib/viewer/model_select.py
index 3c6c4ccdf17..1e65e91a089 100644
--- a/pyomo/contrib/viewer/model_select.py
+++ b/pyomo/contrib/viewer/model_select.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -60,31 +60,33 @@ def select_model(self):
         items = self.tableWidget.selectedItems()
         if len(items) == 0:
             return
-        self.ui_data.model = self.models[items[0].row()]
+        self.ui_data.model_var_name_in_main = self.models[items[0].row()][1]
+        self.ui_data.model = self.models[items[0].row()][0]
         self.close()
 
     def update_models(self):
         import __main__
 
-        s = __main__.__dict__
+        s = dir(__main__)
         keys = []
         for k in s:
-            if isinstance(s[k], pyo.Block):
+            if isinstance(getattr(__main__, k), pyo.Block):
                 keys.append(k)
         self.tableWidget.clearContents()
         self.tableWidget.setRowCount(len(keys))
         self.models = []
         for row, k in enumerate(sorted(keys)):
+            model = getattr(__main__, k)
             item = myqt.QTableWidgetItem()
             item.setText(k)
             self.tableWidget.setItem(row, 0, item)
             item = myqt.QTableWidgetItem()
             try:
-                item.setText(s[k].name)
+                item.setText(model.name)
             except:
                 item.setText("None")
             self.tableWidget.setItem(row, 1, item)
             item = myqt.QTableWidgetItem()
-            item.setText(str(type(s[k])))
+            item.setText(str(type(model)))
             self.tableWidget.setItem(row, 2, item)
-            self.models.append(s[k])
+            self.models.append((model, k))
diff --git a/pyomo/contrib/viewer/pyomo_viewer.py b/pyomo/contrib/viewer/pyomo_viewer.py
index a8fec745af4..e4f75c86840 100644
--- a/pyomo/contrib/viewer/pyomo_viewer.py
+++ b/pyomo/contrib/viewer/pyomo_viewer.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -41,7 +41,7 @@ class QtApp(
         model
     except NameError:
         model=None
-    ui, model = get_mainwindow(model=model, ask_close=False)
+    ui = get_mainwindow(model=model, ask_close=False)
 ui.setWindowTitle('Pyomo Model Viewer -- {}')"""
 
     _kernel_cmd_hide_ui = """try:
diff --git a/pyomo/contrib/viewer/qt.py b/pyomo/contrib/viewer/qt.py
index 150fa3560f6..2715d275758 100644
--- a/pyomo/contrib/viewer/qt.py
+++ b/pyomo/contrib/viewer/qt.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/viewer/report.py b/pyomo/contrib/viewer/report.py
index 6f212b2fbc3..a28e0082212 100644
--- a/pyomo/contrib/viewer/report.py
+++ b/pyomo/contrib/viewer/report.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -50,7 +50,7 @@ def get_residual(ui_data, c):
             values of the constraint body. This function uses the cached values
             and will not trigger recalculation. If variable values have changed,
             this may not yield accurate results.
-        c(_ConstraintData): a constraint or constraint data
+        c(ConstraintData): a constraint or constraint data
     Returns:
         (float) residual
     """
@@ -149,7 +149,7 @@ def degrees_of_freedom(blk):
     Return the degrees of freedom.
 
     Args:
-        blk (Block or _BlockData): Block to count degrees of freedom in
+        blk (Block or BlockData): Block to count degrees of freedom in
     Returns:
         (int): Number of degrees of freedom
     """
diff --git a/pyomo/contrib/viewer/residual_table.py b/pyomo/contrib/viewer/residual_table.py
index 73cf73847e5..94e8902848f 100644
--- a/pyomo/contrib/viewer/residual_table.py
+++ b/pyomo/contrib/viewer/residual_table.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/viewer/tests/__init__.py b/pyomo/contrib/viewer/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/contrib/viewer/tests/__init__.py
+++ b/pyomo/contrib/viewer/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/contrib/viewer/tests/test_data_model_item.py b/pyomo/contrib/viewer/tests/test_data_model_item.py
index f3e7aaf9513..d780b315044 100644
--- a/pyomo/contrib/viewer/tests/test_data_model_item.py
+++ b/pyomo/contrib/viewer/tests/test_data_model_item.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -46,15 +46,10 @@
 from pyomo.contrib.viewer.model_browser import ComponentDataItem
 from pyomo.contrib.viewer.ui_data import UIData
 from pyomo.common.dependencies import DeferredImportError
+from pyomo.core.base.units_container import pint_available
 
-try:
-    x = pyo.units.m
-    units_available = True
-except DeferredImportError:
-    units_available = False
 
-
-@unittest.skipIf(not units_available, "Pyomo units are not available")
+@unittest.skipIf(not pint_available, "Pyomo units are not available")
 class TestDataModelItem(unittest.TestCase):
     def setUp(self):
         # Borrowed this test model from the trust region tests
diff --git a/pyomo/contrib/viewer/tests/test_data_model_tree.py b/pyomo/contrib/viewer/tests/test_data_model_tree.py
index db745aee9ca..2e5c3592198 100644
--- a/pyomo/contrib/viewer/tests/test_data_model_tree.py
+++ b/pyomo/contrib/viewer/tests/test_data_model_tree.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -42,12 +42,7 @@
 from pyomo.contrib.viewer.model_browser import ComponentDataModel
 import pyomo.contrib.viewer.qt as myqt
 from pyomo.common.dependencies import DeferredImportError
-
-try:
-    _x = pyo.units.m
-    units_available = True
-except DeferredImportError:
-    units_available = False
+from pyomo.core.base.units_container import pint_available
 
 available = myqt.available
 
@@ -63,7 +58,7 @@ def __init__(*args, **kwargs):
             pass
 
 
-@unittest.skipIf(not available or not units_available, "PyQt or units not available")
+@unittest.skipIf(not available or not pint_available, "PyQt or units not available")
 class TestDataModel(unittest.TestCase):
     def setUp(self):
         # Borrowed this test model from the trust region tests
diff --git a/pyomo/contrib/viewer/tests/test_qt.py b/pyomo/contrib/viewer/tests/test_qt.py
index 38a022b6668..b7250729cd9 100644
--- a/pyomo/contrib/viewer/tests/test_qt.py
+++ b/pyomo/contrib/viewer/tests/test_qt.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -103,7 +103,7 @@ def blackbox(a, b):
 @unittest.skipIf(not available, "Qt packages are not available.")
 def test_get_mainwindow(qtbot):
     m = get_model()
-    mw, m = get_mainwindow(model=m, testing=True)
+    mw = get_mainwindow(model=m, testing=True)
     assert hasattr(mw, "menuBar")
     assert isinstance(mw.variables, ModelBrowser)
     assert isinstance(mw.constraints, ModelBrowser)
@@ -113,13 +113,13 @@ def test_get_mainwindow(qtbot):
 
 @unittest.skipIf(not available, "Qt packages are not available.")
 def test_close_mainwindow(qtbot):
-    mw, m = get_mainwindow(model=None, testing=True)
+    mw = get_mainwindow(model=None, testing=True)
     mw.exit_action()
 
 
 @unittest.skipIf(not available, "Qt packages are not available.")
 def test_show_model_select_no_models(qtbot):
-    mw, m = get_mainwindow(model=None, testing=True)
+    mw = get_mainwindow(model=None, testing=True)
     ms = mw.show_model_select()
     ms.update_models()
     ms.select_model()
@@ -128,7 +128,7 @@ def test_show_model_select_no_models(qtbot):
 @unittest.skipIf(not available, "Qt packages are not available.")
 def test_model_information(qtbot):
     m = get_model()
-    mw, m = get_mainwindow(model=m, testing=True)
+    mw = get_mainwindow(model=m, testing=True)
     mw.model_information()
     assert isinstance(mw._dialog, QMessageBox)
     text = mw._dialog.text()
@@ -149,7 +149,7 @@ def test_model_information(qtbot):
 @unittest.skipIf(not available, "Qt packages are not available.")
 def test_tree_expand_collapse(qtbot):
     m = get_model()
-    mw, m = get_mainwindow(model=m, testing=True)
+    mw = get_mainwindow(model=m, testing=True)
     mw.variables.treeView.expandAll()
     mw.variables.treeView.collapseAll()
 
@@ -157,7 +157,7 @@ def test_tree_expand_collapse(qtbot):
 @unittest.skipIf(not available, "Qt packages are not available.")
 def test_residual_table(qtbot):
     m = get_model()
-    mw, m = get_mainwindow(model=m, testing=True)
+    mw = get_mainwindow(model=m, testing=True)
     mw.residuals_restart()
     mw.ui_data.calculate_expressions()
     mw.residuals.calculate()
@@ -184,7 +184,7 @@ def test_residual_table(qtbot):
 @unittest.skipIf(not available, "Qt packages are not available.")
 def test_var_tree(qtbot):
     m = get_model()
-    mw, m = get_mainwindow(model=m, testing=True)
+    mw = get_mainwindow(model=m, testing=True)
     qtbot.addWidget(mw)
     mw.variables.treeView.expandAll()
     root_index = mw.variables.datmodel.index(0, 0)
@@ -218,7 +218,7 @@ def test_var_tree(qtbot):
 @unittest.skipIf(not available, "Qt packages are not available.")
 def test_bad_view(qtbot):
     m = get_model()
-    mw, m = get_mainwindow(model=m, testing=True)
+    mw = get_mainwindow(model=m, testing=True)
     err = None
     try:
         mw.badTree = mw._tree_restart(
diff --git a/pyomo/contrib/viewer/tests/test_report.py b/pyomo/contrib/viewer/tests/test_report.py
index b496e2294ff..88044490a77 100644
--- a/pyomo/contrib/viewer/tests/test_report.py
+++ b/pyomo/contrib/viewer/tests/test_report.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/contrib/viewer/ui.py b/pyomo/contrib/viewer/ui.py
index 8a621534b31..ac96e58eea9 100644
--- a/pyomo/contrib/viewer/ui.py
+++ b/pyomo/contrib/viewer/ui.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -66,7 +66,9 @@ class _MainWindow(object):
     _log.error(_err)
 
 
-def get_mainwindow(model=None, show=True, ask_close=True, testing=False):
+def get_mainwindow(
+    model=None, show=True, ask_close=True, model_var_name_in_main=None, testing=False
+):
     """
     Create a UI MainWindow.
 
@@ -79,16 +81,32 @@ def get_mainwindow(model=None, show=True, ask_close=True, testing=False):
         (ui, model): ui is the MainWindow widget, and model is the linked Pyomo
             model.  If no model is provided a new ConcreteModel is created
     """
+    model_name = model_var_name_in_main
     if model is None:
-        model = pyo.ConcreteModel(name="Default")
-    ui = MainWindow(model=model, ask_close=ask_close, testing=testing)
+        import __main__
+
+        if model_name in dir(__main__):
+            if isinstance(getattr(__main__, model_name), pyo.Block):
+                model = getattr(__main__, model_name)
+        else:
+            for s in dir(__main__):
+                if isinstance(getattr(__main__, s), pyo.Block):
+                    model = getattr(__main__, s)
+                    model_name = s
+                    break
+    ui = MainWindow(
+        model=model,
+        model_var_name_in_main=model_name,
+        ask_close=ask_close,
+        testing=testing,
+    )
     try:
         get_ipython().events.register("post_execute", ui.refresh_on_execute)
     except AttributeError:
         pass  # not in ipy kernel, so is fine to not register callback
     if show:
         ui.show()
-    return ui, model
+    return ui
 
 
 class MainWindow(_MainWindow, _MainWindowUI):
@@ -97,6 +115,7 @@ def __init__(self, *args, **kwargs):
         main = self.main = kwargs.pop("main", None)
         ask_close = self.ask_close = kwargs.pop("ask_close", True)
         self.testing = kwargs.pop("testing", False)
+        model_var_name_in_main = kwargs.pop("model_var_name_in_main", None)
         flags = kwargs.pop("flags", 0)
         self.ui_data = UIData(model=model)
         super().__init__(*args, **kwargs)
@@ -128,6 +147,7 @@ def __init__(self, *args, **kwargs):
         self.actionCalculateExpressions.triggered.connect(
             self.ui_data.calculate_expressions
         )
+        self.ui_data.model_var_name_in_main = model_var_name_in_main
         self.actionTile.triggered.connect(self.mdiArea.tileSubWindows)
         self.actionCascade.triggered.connect(self.mdiArea.cascadeSubWindows)
         self.actionTabs.triggered.connect(self.toggle_tabs)
@@ -256,6 +276,18 @@ def refresh_on_execute(self):
         ipython kernel.  The main purpose of this right now it to refresh the
         UI display so that it matches the current state of the model.
         """
+        if self.ui_data.model_var_name_in_main is not None:
+            import __main__
+
+            try:
+                mname = self.ui_data.model_var_name_in_main
+                mid = id(getattr(__main__, mname))
+                if id(self.ui_data.model) != mid:
+                    self.ui_data.model = getattr(__main__, mname)
+                    self.update_model
+                    return
+            except AttributeError:
+                pass
         for w in self._refresh_list:
             try:
                 w.refresh()
diff --git a/pyomo/contrib/viewer/ui_data.py b/pyomo/contrib/viewer/ui_data.py
index 8bbaac14e13..8d83be91e5f 100644
--- a/pyomo/contrib/viewer/ui_data.py
+++ b/pyomo/contrib/viewer/ui_data.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -39,16 +39,27 @@ class UIDataNoUi(object):
     UIData.  The class is split this way for testing when PyQt is not available.
     """
 
-    def __init__(self, model=None):
+    def __init__(self, model=None, model_var_name_in_main=None):
         """
         This class holds the basic UI setup, but doesn't depend on Qt. It
         shouldn't really be used except for testing when Qt is not available.
 
         Args:
             model: The Pyomo model to view
+            model_var_name_in_main: if this is set, check that the model variable
+                which points to a model object in __main__ has the same id when
+                the UI is refreshed due to a command being executed in jupyter
+                notebook or QtConsole, if not the same id, then update the model
+                Since the model viewer is not necessarily pointed at a model in the
+                __main__ namespace only set this if you want the model to auto
+                update.  Since the model selector dialog lets you choose models
+                from the __main__ namespace it sets this when you select a model.
+                This is useful if you run a script repeatedly that replaces a model
+                preventing you from looking at a previous version of the model.
         """
         super().__init__()
         self._model = None
+        self.model_var_name_in_main = model_var_name_in_main
         self._begin_update = False
         self.value_cache = ComponentMap()
         self.value_cache_units = ComponentMap()
diff --git a/pyomo/core/__init__.py b/pyomo/core/__init__.py
index 5cbebcee9ec..f0d168d98f9 100644
--- a/pyomo/core/__init__.py
+++ b/pyomo/core/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -33,6 +33,8 @@
     exactly,
     atleast,
     atmost,
+    all_different,
+    count_if,
     implies,
     lnot,
     xor,
@@ -99,7 +101,7 @@
     BooleanValue,
     native_logical_values,
 )
-from pyomo.core.kernel.objective import minimize, maximize
+from pyomo.core.base import minimize, maximize
 from pyomo.core.base.config import PyomoOptions
 
 from pyomo.core.base.expression import Expression
diff --git a/pyomo/core/base/PyomoModel.py b/pyomo/core/base/PyomoModel.py
index 055f6f8450a..22bbc5fa02b 100644
--- a/pyomo/core/base/PyomoModel.py
+++ b/pyomo/core/base/PyomoModel.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,8 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['Model', 'ConcreteModel', 'AbstractModel', 'global_option']
-
 import logging
 import sys
 from weakref import ref as weakref_ref
@@ -20,7 +18,7 @@
 from pyomo.common import timing
 from pyomo.common.collections import Bunch
 from pyomo.common.dependencies import pympler, pympler_available
-from pyomo.common.deprecation import deprecated, deprecation_warning
+from pyomo.common.deprecation import deprecated
 from pyomo.common.gc_manager import PauseGC
 from pyomo.common.log import is_debug_set
 from pyomo.common.numeric_types import value
@@ -34,11 +32,10 @@
 from pyomo.core.base.block import ScalarBlock
 from pyomo.core.base.set import Set
 from pyomo.core.base.componentuid import ComponentUID
-from pyomo.core.base.transformation import TransformationFactory
 from pyomo.core.base.label import CNameLabeler, CuidLabeler
 from pyomo.dataportal.DataPortal import DataPortal
 
-from pyomo.opt.results import SolverResults, Solution, SolverStatus, UndefinedData
+from pyomo.opt.results import Solution, SolverStatus, UndefinedData
 
 from contextlib import nullcontext
 from io import StringIO
@@ -789,7 +786,7 @@ def _load_model_data(self, modeldata, namespaces, **kwds):
             profile_memory = kwds.get('profile_memory', 0)
 
             if profile_memory >= 2 and pympler_available:
-                mem_used = pympler.muppy.get_size(muppy.get_objects())
+                mem_used = pympler.muppy.get_size(pympler.muppy.get_objects())
                 print("")
                 print(
                     "      Total memory = %d bytes prior to model "
@@ -798,7 +795,7 @@ def _load_model_data(self, modeldata, namespaces, **kwds):
 
                 if profile_memory >= 3:
                     gc.collect()
-                    mem_used = pympler.muppy.get_size(muppy.get_objects())
+                    mem_used = pympler.muppy.get_size(pympler.muppy.get_objects())
                     print(
                         "      Total memory = %d bytes prior to model "
                         "construction (after garbage collection)" % mem_used
diff --git a/pyomo/core/base/__init__.py b/pyomo/core/base/__init__.py
index f7815f1676b..6b295196864 100644
--- a/pyomo/core/base/__init__.py
+++ b/pyomo/core/base/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -12,6 +12,7 @@
 # TODO: this import is for historical backwards compatibility and should
 # probably be removed
 from pyomo.common.collections import ComponentMap
+from pyomo.common.enums import minimize, maximize
 
 from pyomo.core.expr.symbol_map import SymbolMap
 from pyomo.core.expr.numvalue import (
@@ -33,10 +34,11 @@
     BooleanValue,
     native_logical_values,
 )
-from pyomo.core.kernel.objective import minimize, maximize
-from pyomo.core.base.config import PyomoOptions
 
-from pyomo.core.base.expression import Expression, _ExpressionData
+from pyomo.core.base.component import name, Component, ModelComponentFactory
+from pyomo.core.base.componentuid import ComponentUID
+from pyomo.core.base.config import PyomoOptions
+from pyomo.core.base.enums import SortComponents, TraversalStrategy
 from pyomo.core.base.label import (
     CuidLabeler,
     CounterLabeler,
@@ -47,56 +49,73 @@
     NameLabeler,
     ShortNameLabeler,
 )
+from pyomo.core.base.misc import display
+from pyomo.core.base.reference import Reference
+from pyomo.core.base.symbol_map import symbol_map_from_instance
+from pyomo.core.base.transformation import (
+    Transformation,
+    TransformationFactory,
+    ReverseTransformationToken,
+)
+
+from pyomo.core.base.PyomoModel import (
+    global_option,
+    ModelSolution,
+    ModelSolutions,
+    Model,
+    ConcreteModel,
+    AbstractModel,
+)
 
 #
 # Components
 #
-from pyomo.core.base.component import name, Component, ModelComponentFactory
-from pyomo.core.base.componentuid import ComponentUID
 from pyomo.core.base.action import BuildAction
-from pyomo.core.base.check import BuildCheck
-from pyomo.core.base.set import Set, SetOf, simple_set_rule, RangeSet
-from pyomo.core.base.param import Param
-from pyomo.core.base.var import Var, _VarData, _GeneralVarData, ScalarVar, VarList
+from pyomo.core.base.block import (
+    Block,
+    BlockData,
+    ScalarBlock,
+    active_components,
+    components,
+    active_components_data,
+    components_data,
+)
 from pyomo.core.base.boolean_var import (
     BooleanVar,
-    _BooleanVarData,
-    _GeneralBooleanVarData,
+    BooleanVarData,
     BooleanVarList,
     ScalarBooleanVar,
 )
+from pyomo.core.base.check import BuildCheck
+from pyomo.core.base.connector import Connector, ConnectorData
 from pyomo.core.base.constraint import (
     simple_constraint_rule,
     simple_constraintlist_rule,
     ConstraintList,
     Constraint,
-    _ConstraintData,
+    ConstraintData,
 )
+from pyomo.core.base.expression import Expression, NamedExpressionData, ExpressionData
+from pyomo.core.base.external import ExternalFunction
 from pyomo.core.base.logical_constraint import (
     LogicalConstraint,
     LogicalConstraintList,
-    _LogicalConstraintData,
+    LogicalConstraintData,
 )
 from pyomo.core.base.objective import (
     simple_objective_rule,
     simple_objectivelist_rule,
     Objective,
     ObjectiveList,
-    _ObjectiveData,
-)
-from pyomo.core.base.connector import Connector
-from pyomo.core.base.sos import SOSConstraint
-from pyomo.core.base.piecewise import Piecewise
-from pyomo.core.base.suffix import (
-    active_export_suffix_generator,
-    active_import_suffix_generator,
-    Suffix,
+    ObjectiveData,
 )
-from pyomo.core.base.external import ExternalFunction
-from pyomo.core.base.symbol_map import symbol_map_from_instance
-from pyomo.core.base.reference import Reference
-
+from pyomo.core.base.param import Param, ParamData
+from pyomo.core.base.piecewise import Piecewise, PiecewiseData
 from pyomo.core.base.set import (
+    Set,
+    SetData,
+    SetOf,
+    RangeSet,
     Reals,
     PositiveReals,
     NonPositiveReals,
@@ -116,34 +135,21 @@
     PercentFraction,
     RealInterval,
     IntegerInterval,
+    simple_set_rule,
 )
-from pyomo.core.base.misc import display
-from pyomo.core.base.block import (
-    Block,
-    ScalarBlock,
-    active_components,
-    components,
-    active_components_data,
-    components_data,
-)
-from pyomo.core.base.enums import SortComponents, TraversalStrategy
-from pyomo.core.base.PyomoModel import (
-    global_option,
-    ModelSolution,
-    ModelSolutions,
-    Model,
-    ConcreteModel,
-    AbstractModel,
-)
-from pyomo.core.base.transformation import (
-    Transformation,
-    TransformationFactory,
-    ReverseTransformationToken,
+from pyomo.core.base.sos import SOSConstraint, SOSConstraintData
+from pyomo.core.base.suffix import (
+    active_export_suffix_generator,
+    active_import_suffix_generator,
+    Suffix,
 )
+from pyomo.core.base.var import Var, VarData, ScalarVar, VarList
 
 from pyomo.core.base.instance2dat import instance2dat
 
+#
 # These APIs are deprecated and should be removed in the near future
+#
 from pyomo.core.base.set import set_options, RealSet, IntegerSet, BooleanSet
 
 from pyomo.common.deprecation import relocated_module_attribute
@@ -155,4 +161,25 @@
 relocated_module_attribute(
     'SimpleBooleanVar', 'pyomo.core.base.boolean_var.SimpleBooleanVar', version='6.0'
 )
+# Historically, only a subset of "private" component data classes were imported here
+relocated_module_attribute(
+    f'_GeneralVarData', f'pyomo.core.base.VarData', version='6.7.2'
+)
+relocated_module_attribute(
+    f'_GeneralBooleanVarData', f'pyomo.core.base.BooleanVarData', version='6.7.2'
+)
+relocated_module_attribute(
+    f'_ExpressionData', f'pyomo.core.base.NamedExpressionData', version='6.7.2'
+)
+for _cdata in (
+    'ConstraintData',
+    'LogicalConstraintData',
+    'VarData',
+    'BooleanVarData',
+    'ObjectiveData',
+):
+    relocated_module_attribute(
+        f'_{_cdata}', f'pyomo.core.base.{_cdata}', version='6.7.2'
+    )
+del _cdata
 del relocated_module_attribute
diff --git a/pyomo/core/base/action.py b/pyomo/core/base/action.py
index b54beab8584..d24d94fe05a 100644
--- a/pyomo/core/base/action.py
+++ b/pyomo/core/base/action.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,8 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['BuildAction']
-
 import logging
 import types
 
@@ -24,7 +22,8 @@
 
 
 @ModelComponentFactory.register(
-    "A component that performs arbitrary actions during model construction.  The action rule is applied to every index value."
+    "A component that performs arbitrary actions during model construction.  "
+    "The action rule is applied to every index value."
 )
 class BuildAction(IndexedComponent):
     """A build action, which executes a rule for all valid indices.
diff --git a/pyomo/core/base/block.py b/pyomo/core/base/block.py
index 89e872ebbe5..653809e0419 100644
--- a/pyomo/core/base/block.py
+++ b/pyomo/core/base/block.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,31 +9,20 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = [
-    'Block',
-    'TraversalStrategy',
-    'SortComponents',
-    'active_components',
-    'components',
-    'active_components_data',
-    'components_data',
-    'SimpleBlock',
-    'ScalarBlock',
-]
-
+from __future__ import annotations
 import copy
-import enum
 import logging
 import sys
 import weakref
 import textwrap
-from contextlib import contextmanager
 
-from inspect import isclass
+from collections import defaultdict
+from contextlib import contextmanager
+from inspect import isclass, currentframe
+from io import StringIO
 from itertools import filterfalse, chain
 from operator import itemgetter, attrgetter
-from io import StringIO
-from pyomo.common.pyomo_typing import overload
+from typing import Union, Any, Type
 
 from pyomo.common.autoslots import AutoSlots
 from pyomo.common.collections import Mapping
@@ -41,7 +30,7 @@
 from pyomo.common.formatting import StreamIndenter
 from pyomo.common.gc_manager import PauseGC
 from pyomo.common.log import is_debug_set
-from pyomo.common.sorting import sorted_robust
+from pyomo.common.pyomo_typing import overload
 from pyomo.common.timing import ConstructionTimer
 from pyomo.core.base.component import (
     Component,
@@ -51,12 +40,13 @@
 from pyomo.core.base.enums import SortComponents, TraversalStrategy
 from pyomo.core.base.global_set import UnindexedComponent_index
 from pyomo.core.base.componentuid import ComponentUID
-from pyomo.core.base.set import Any, GlobalSetBase, _SetDataBase
+from pyomo.core.base.set import Any
 from pyomo.core.base.var import Var
 from pyomo.core.base.initializer import Initializer
 from pyomo.core.base.indexed_component import (
     ActiveIndexedComponent,
     UnindexedComponent_set,
+    IndexedComponent,
 )
 
 from pyomo.opt.base import ProblemFormat, guess_format
@@ -170,13 +160,13 @@ def __init__(self):
         self.seen_data = set()
 
     def unique(self, comp, items, are_values):
-        """Returns generator that filters duplicate _ComponentData objects from items
+        """Returns generator that filters duplicate ComponentData objects from items
 
         Parameters
         ----------
         comp: ComponentBase
            The Component (indexed or scalar) that contains all
-           _ComponentData returned by the `items` generator.  `comp` may
+           ComponentData returned by the `items` generator.  `comp` may
            be an IndexedComponent generated by :py:func:`Reference` (and
            hence may not own the component datas in `items`)
 
@@ -185,8 +175,8 @@ def unique(self, comp, items, are_values):
             `comp` Component.
 
         are_values: bool
-            If `True`, `items` yields _ComponentData objects, otherwise,
-            `items` yields `(index, _ComponentData)` tuples.
+            If `True`, `items` yields ComponentData objects, otherwise,
+            `items` yields `(index, ComponentData)` tuples.
 
         """
         if comp.is_reference():
@@ -264,7 +254,7 @@ class _BlockConstruction(object):
 class PseudoMap(AutoSlots.Mixin):
     """
     This class presents a "mock" dict interface to the internal
-    _BlockData data structures.  We return this object to the
+    BlockData data structures.  We return this object to the
     user to preserve the historical "{ctype : {name : obj}}"
     interface without actually regenerating that dict-of-dicts data
     structure.
@@ -497,7 +487,7 @@ def iteritems(self):
         return self.items()
 
 
-class _BlockData(ActiveComponentData):
+class BlockData(ActiveComponentData):
     """
     This class holds the fundamental block data.
     """
@@ -547,11 +537,12 @@ def __init__(self, component):
         #   _ctypes:      { ctype -> [1st idx, last idx, count] }
         #   _decl:        { name -> idx }
         #   _decl_order:  list( tuples( obj, next_type_idx ) )
-        super(_BlockData, self).__setattr__('_ctypes', {})
-        super(_BlockData, self).__setattr__('_decl', {})
-        super(_BlockData, self).__setattr__('_decl_order', [])
+        super(BlockData, self).__setattr__('_ctypes', {})
+        super(BlockData, self).__setattr__('_decl', {})
+        super(BlockData, self).__setattr__('_decl_order', [])
+        self._private_data = None
 
-    def __getattr__(self, val):
+    def __getattr__(self, val) -> Union[Component, IndexedComponent, Any]:
         if val in ModelComponentFactory:
             return _component_decorator(self, ModelComponentFactory.get_class(val))
         # Since the base classes don't support getattr, we can just
@@ -560,7 +551,7 @@ def __getattr__(self, val):
             "'%s' object has no attribute '%s'" % (self.__class__.__name__, val)
         )
 
-    def __setattr__(self, name, val):
+    def __setattr__(self, name: str, val: Union[Component, IndexedComponent, Any]):
         """
         Set an attribute of a block data object.
         """
@@ -583,7 +574,7 @@ def __setattr__(self, name, val):
                 # Other Python objects are added with the standard __setattr__
                 # method.
                 #
-                super(_BlockData, self).__setattr__(name, val)
+                super(BlockData, self).__setattr__(name, val)
         #
         # Case 2.  The attribute exists and it is a component in the
         #          list of declarations in this block.  We will use the
@@ -637,11 +628,11 @@ def __setattr__(self, name, val):
         #
         else:
             #
-            # NB: This is important: the _BlockData is either a scalar
+            # NB: This is important: the BlockData is either a scalar
             # Block (where _parent and _component are defined) or a
             # single block within an Indexed Block (where only
             # _component is defined).  Regardless, the
-            # _BlockData.__init__() method declares these methods and
+            # BlockData.__init__() method declares these methods and
             # sets them either to None or a weakref.  Thus, we will
             # never have a problem converting these objects from
             # weakrefs into Blocks and back (when pickling); the
@@ -656,23 +647,23 @@ def __setattr__(self, name, val):
             # return True, this shouldn't be too inefficient.
             #
             if name == '_parent':
-                if val is not None and not isinstance(val(), _BlockData):
+                if val is not None and not isinstance(val(), BlockData):
                     raise ValueError(
                         "Cannot set the '_parent' attribute of Block '%s' "
                         "to a non-Block object (with type=%s); Did you "
                         "try to create a model component named '_parent'?"
                         % (self.name, type(val))
                     )
-                super(_BlockData, self).__setattr__(name, val)
+                super(BlockData, self).__setattr__(name, val)
             elif name == '_component':
-                if val is not None and not isinstance(val(), _BlockData):
+                if val is not None and not isinstance(val(), BlockData):
                     raise ValueError(
                         "Cannot set the '_component' attribute of Block '%s' "
                         "to a non-Block object (with type=%s); Did you "
                         "try to create a model component named '_component'?"
                         % (self.name, type(val))
                     )
-                super(_BlockData, self).__setattr__(name, val)
+                super(BlockData, self).__setattr__(name, val)
             #
             # At this point, we should only be seeing non-component data
             # the user is hanging on the blocks (uncommon) or the
@@ -689,7 +680,7 @@ def __setattr__(self, name, val):
                 delattr(self, name)
                 self.add_component(name, val)
             else:
-                super(_BlockData, self).__setattr__(name, val)
+                super(BlockData, self).__setattr__(name, val)
 
     def __delattr__(self, name):
         """
@@ -712,7 +703,7 @@ def __delattr__(self, name):
             # Other Python objects are removed with the standard __detattr__
             # method.
             #
-            super(_BlockData, self).__delattr__(name)
+            super(BlockData, self).__delattr__(name)
 
     def _compact_decl_storage(self):
         idxMap = {}
@@ -784,11 +775,11 @@ def transfer_attributes_from(self, src):
 
         Parameters
         ----------
-        src: _BlockData or dict
+        src: BlockData or dict
             The Block or mapping that contains the new attributes to
             assign to this block.
         """
-        if isinstance(src, _BlockData):
+        if isinstance(src, BlockData):
             # There is a special case where assigning a parent block to
             # this block creates a circular hierarchy
             if src is self:
@@ -797,7 +788,7 @@ def transfer_attributes_from(self, src):
             while p_block is not None:
                 if p_block is src:
                     raise ValueError(
-                        "_BlockData.transfer_attributes_from(): Cannot set a "
+                        "BlockData.transfer_attributes_from(): Cannot set a "
                         "sub-block (%s) to a parent block (%s): creates a "
                         "circular hierarchy" % (self, src)
                     )
@@ -813,7 +804,7 @@ def transfer_attributes_from(self, src):
             del_src_comp = lambda x: None
         else:
             raise ValueError(
-                "_BlockData.transfer_attributes_from(): expected a "
+                "BlockData.transfer_attributes_from(): expected a "
                 "Block or dict; received %s" % (type(src).__name__,)
             )
 
@@ -846,47 +837,6 @@ def transfer_attributes_from(self, src):
             ):
                 setattr(self, k, v)
 
-    def _add_implicit_sets(self, val):
-        """TODO: This method has known issues (see tickets) and needs to be
-        reviewed. [JDS 9/2014]"""
-
-        _component_sets = getattr(val, '_implicit_subsets', None)
-        #
-        # FIXME: The name attribute should begin with "_", and None
-        # should replace "_unknown_"
-        #
-        if _component_sets is not None:
-            for ctr, tset in enumerate(_component_sets):
-                if tset.parent_component().parent_block() is None and not isinstance(
-                    tset.parent_component(), GlobalSetBase
-                ):
-                    self.add_component("%s_index_%d" % (val.local_name, ctr), tset)
-        if (
-            getattr(val, '_index_set', None) is not None
-            and isinstance(val._index_set, _SetDataBase)
-            and val._index_set.parent_component().parent_block() is None
-            and not isinstance(val._index_set.parent_component(), GlobalSetBase)
-        ):
-            self.add_component(
-                "%s_index" % (val.local_name,), val._index_set.parent_component()
-            )
-        if (
-            getattr(val, 'initialize', None) is not None
-            and isinstance(val.initialize, _SetDataBase)
-            and val.initialize.parent_component().parent_block() is None
-            and not isinstance(val.initialize.parent_component(), GlobalSetBase)
-        ):
-            self.add_component(
-                "%s_index_init" % (val.local_name,), val.initialize.parent_component()
-            )
-        if (
-            getattr(val, 'domain', None) is not None
-            and isinstance(val.domain, _SetDataBase)
-            and val.domain.parent_block() is None
-            and not isinstance(val.domain, GlobalSetBase)
-        ):
-            self.add_component("%s_domain" % (val.local_name,), val.domain)
-
     def collect_ctypes(self, active=None, descend_into=True):
         """
         Count all component types stored on or under this
@@ -928,7 +878,7 @@ def collect_ctypes(self, active=None, descend_into=True):
 
     def model(self):
         #
-        # Special case: the "Model" is always the top-level _BlockData,
+        # Special case: the "Model" is always the top-level BlockData,
         # so if this is the top-level block, it must be the model
         #
         # Also note the interesting and intentional characteristic for
@@ -1066,16 +1016,11 @@ def add_component(self, name, val):
         val._parent = weakref.ref(self)
         val._name = name
         #
-        # We want to add the temporary / implicit sets first so that
-        # they get constructed before this component
-        #
-        # FIXME: This is sloppy and wasteful (most components trigger
-        # this, even when there is no need for it).  We should
-        # reconsider the whole _implicit_subsets logic to defer this
-        # kind of thing to an "update_parent()" method on the
-        # components.
+        # Update the context of any anonymous sets
         #
-        self._add_implicit_sets(val)
+        if getattr(val, '_anonymous_sets', None) is not None:
+            for _set in val._anonymous_sets:
+                _set._parent = val._parent
         #
         # Add the component to the underlying Component store
         #
@@ -1090,7 +1035,7 @@ def add_component(self, name, val):
         # is inappropriate here.  The correct way to add the attribute
         # is to delegate the work to the next class up the MRO.
         #
-        super(_BlockData, self).__setattr__(name, val)
+        super(BlockData, self).__setattr__(name, val)
         #
         # Update the ctype linked lists
         #
@@ -1112,26 +1057,13 @@ def add_component(self, name, val):
         # Error, for disabled support implicit rule names
         #
         if '_rule' in val.__dict__ and val._rule is None:
-            _found = False
             try:
                 _test = val.local_name + '_rule'
                 for i in (1, 2):
                     frame = sys._getframe(i)
-                    _found |= _test in frame.f_locals
             except:
                 pass
-            if _found:
-                # JDS: Do not blindly reformat this message.  The
-                # formatter inserts arbitrarily-long names(), which can
-                # cause the resulting logged message to be very poorly
-                # formatted due to long lines.
-                logger.warning(
-                    """As of Pyomo 4.0, Pyomo components no longer support implicit rules.
-You defined a component (%s) that appears
-to rely on an implicit rule (%s).
-Components must now specify their rules explicitly using 'rule=' keywords."""
-                    % (val.name, _test)
-                )
+
         #
         # Don't reconstruct if this component has already been constructed.
         # This allows a user to move a component from one block to
@@ -1148,9 +1080,8 @@ def add_component(self, name, val):
         #   added to the class by Block.__init__()
         #
         if getattr(_component, '_constructed', False):
-            # NB: we don't have to construct the temporary / implicit
-            # sets here: if necessary, that happens when
-            # _add_implicit_sets() calls add_component().
+            # NB: we don't have to construct the anonymous sets here: if
+            # necessary, that happens in component.construct()
             if _BlockConstruction.data:
                 data = _BlockConstruction.data.get(id(self), None)
                 if data is not None:
@@ -1162,7 +1093,7 @@ def add_component(self, name, val):
                 # This is tricky: If we are in the middle of
                 # constructing an indexed block, the block component
                 # already has _constructed=True.  Now, if the
-                # _BlockData.__init__() defines any local variables
+                # BlockData.__init__() defines any local variables
                 # (like pyomo.gdp.Disjunct's indicator_var), name(True)
                 # will fail: this block data exists and has a parent(),
                 # but it has not yet been added to the parent's _data
@@ -1237,6 +1168,10 @@ def del_component(self, name_or_object):
 
         # Clear the _parent attribute
         obj._parent = None
+        # Update the context of any anonymous sets
+        if getattr(obj, '_anonymous_sets', None) is not None:
+            for _set in obj._anonymous_sets:
+                _set._parent = None
 
         # Now that this component is not in the _decl map, we can call
         # delattr as usual.
@@ -1246,7 +1181,7 @@ def del_component(self, name_or_object):
         # Note: 'del self.__dict__[name]' is inappropriate here.  The
         # correct way to add the attribute is to delegate the work to
         # the next class up the MRO.
-        super(_BlockData, self).__delattr__(name)
+        super(BlockData, self).__delattr__(name)
 
     def reclassify_component_type(
         self, name_or_object, new_ctype, preserve_declaration_order=True
@@ -1451,7 +1386,7 @@ def _component_data_iteritems(self, ctype, active, sort, dedup):
 
         Generator that returns a nested 2-tuple of
 
-            ((component name, index value), _ComponentData)
+            ((component name, index value), ComponentData)
 
         for every component data in the block matching the specified
         ctype(s).
@@ -1468,7 +1403,7 @@ def _component_data_iteritems(self, ctype, active, sort, dedup):
             Iterate over the components in a specified sorted order
 
         dedup: _DeduplicateInfo
-            Deduplicator to prevent returning the same _ComponentData twice
+            Deduplicator to prevent returning the same ComponentData twice
         """
         for name, comp in PseudoMap(self, ctype, active, sort).items():
             # NOTE: Suffix has a dict interface (something other derived
@@ -1504,7 +1439,7 @@ def _component_data_iteritems(self, ctype, active, sort, dedup):
             yield from dedup.unique(comp, _items, False)
 
     def _component_data_itervalues(self, ctype, active, sort, dedup):
-        """Generator that returns the _ComponentData for every component data
+        """Generator that returns the ComponentData for every component data
         in the block.
 
         Parameters
@@ -1519,7 +1454,7 @@ def _component_data_itervalues(self, ctype, active, sort, dedup):
             Iterate over the components in a specified sorted order
 
         dedup: _DeduplicateInfo
-            Deduplicator to prevent returning the same _ComponentData twice
+            Deduplicator to prevent returning the same ComponentData twice
         """
         for comp in PseudoMap(self, ctype, active, sort).values():
             # NOTE: Suffix has a dict interface (something other derived
@@ -1625,7 +1560,7 @@ def component_data_iterindex(
         generator recursively descends into sub-blocks.  The
         tuple is
 
-            ((component name, index value), _ComponentData)
+            ((component name, index value), ComponentData)
 
         """
         dedup = _DeduplicateInfo()
@@ -2028,6 +1963,28 @@ def _create_objects_for_deepcopy(self, memo, component_list):
                 comp._create_objects_for_deepcopy(memo, component_list)
         return _ans
 
+    def private_data(self, scope=None):
+        mod = currentframe().f_back.f_globals['__name__']
+        if scope is None:
+            scope = mod
+        elif not mod.startswith(scope):
+            raise ValueError(
+                "All keys in the 'private_data' dictionary must "
+                "be substrings of the caller's module name. "
+                "Received '%s' when calling private_data on Block "
+                "'%s'." % (scope, self.name)
+            )
+        if self._private_data is None:
+            self._private_data = {}
+        if scope not in self._private_data:
+            self._private_data[scope] = Block._private_data_initializers[scope]()
+        return self._private_data[scope]
+
+
+class _BlockData(metaclass=RenamedClass):
+    __renamed__new_class__ = BlockData
+    __renamed__version__ = '6.7.2'
+
 
 @ModelComponentFactory.register(
     "A component that contains one or more model components."
@@ -2042,7 +1999,19 @@ class Block(ActiveIndexedComponent):
     is deferred.
     """
 
-    _ComponentDataClass = _BlockData
+    _ComponentDataClass = BlockData
+    _private_data_initializers = defaultdict(lambda: dict)
+
+    @overload
+    def __new__(
+        cls: Type[Block], *args, **kwds
+    ) -> Union[ScalarBlock, IndexedBlock]: ...
+
+    @overload
+    def __new__(cls: Type[ScalarBlock], *args, **kwds) -> ScalarBlock: ...
+
+    @overload
+    def __new__(cls: Type[IndexedBlock], *args, **kwds) -> IndexedBlock: ...
 
     def __new__(cls, *args, **kwds):
         if cls != Block:
@@ -2123,7 +2092,7 @@ def _getitem_when_not_present(self, idx):
             # components declared by the rule have the opportunity
             # to be initialized with data from
             # _BlockConstruction.data as they are transferred over.
-            if obj is not _block and isinstance(obj, _BlockData):
+            if obj is not _block and isinstance(obj, BlockData):
                 _block.transfer_attributes_from(obj)
         finally:
             if data is not None and _block is not self:
@@ -2138,6 +2107,11 @@ def construct(self, data=None):
         """
         Initialize the block
         """
+        if self._constructed:
+            return
+        self._constructed = True
+
+        timer = ConstructionTimer(self)
         if is_debug_set(logger):
             logger.debug(
                 "Constructing %s '%s', from data=%s",
@@ -2145,10 +2119,10 @@ def construct(self, data=None):
                 self.name,
                 str(data),
             )
-        if self._constructed:
-            return
-        timer = ConstructionTimer(self)
-        self._constructed = True
+
+        if self._anonymous_sets is not None:
+            for _set in self._anonymous_sets:
+                _set.construct()
 
         # Constructing blocks is tricky.  Scalar blocks are already
         # partially constructed (they have _data[None] == self) in order
@@ -2239,12 +2213,29 @@ def display(self, filename=None, ostream=None, prefix=""):
             ostream = sys.stdout
 
         for key in sorted(self):
-            _BlockData.display(self[key], filename, ostream, prefix)
+            BlockData.display(self[key], filename, ostream, prefix)
+
+    @staticmethod
+    def register_private_data_initializer(initializer, scope=None):
+        mod = currentframe().f_back.f_globals['__name__']
+        if scope is None:
+            scope = mod
+        elif not mod.startswith(scope):
+            raise ValueError(
+                "'private_data' scope must be substrings of the caller's module name. "
+                f"Received '{scope}' when calling register_private_data_initializer()."
+            )
+        if scope in Block._private_data_initializers:
+            raise RuntimeError(
+                "Duplicate initializer registration for 'private_data' dictionary "
+                f"(scope={scope})"
+            )
+        Block._private_data_initializers[scope] = initializer
 
 
-class ScalarBlock(_BlockData, Block):
+class ScalarBlock(BlockData, Block):
     def __init__(self, *args, **kwds):
-        _BlockData.__init__(self, component=self)
+        BlockData.__init__(self, component=self)
         Block.__init__(self, *args, **kwds)
         # Initialize the data dict so that (abstract) attribute
         # assignment will work.  Note that we do not trigger
@@ -2266,6 +2257,11 @@ class IndexedBlock(Block):
     def __init__(self, *args, **kwds):
         Block.__init__(self, *args, **kwds)
 
+    @overload
+    def __getitem__(self, index) -> BlockData: ...
+
+    __getitem__ = IndexedComponent.__getitem__  # type: ignore
+
 
 #
 # Deprecated functions.
@@ -2321,101 +2317,120 @@ def components_data(block, ctype, sort=None, sort_by_keys=False, sort_by_names=F
 # Create a Block and record all the default attributes, methods, etc.
 # These will be assumed to be the set of illegal component names.
 #
-_BlockData._Block_reserved_words = set(dir(Block()))
-
+BlockData._Block_reserved_words = set(dir(Block()))
 
-class _IndexedCustomBlockMeta(type):
-    """Metaclass for creating an indexed custom block."""
 
-    pass
-
-
-class _ScalarCustomBlockMeta(type):
-    """Metaclass for creating a scalar custom block."""
-
-    def __new__(meta, name, bases, dct):
-        def __init__(self, *args, **kwargs):
-            # bases[0] is the custom block data object
-            bases[0].__init__(self, component=self)
-            # bases[1] is the custom block object that
-            # is used for declaration
-            bases[1].__init__(self, *args, **kwargs)
-
-        dct["__init__"] = __init__
-        return type.__new__(meta, name, bases, dct)
+class ScalarCustomBlockMixin(object):
+    def __init__(self, *args, **kwargs):
+        # __bases__ for the ScalarCustomBlock is
+        #
+        #    (ScalarCustomBlockMixin, {custom_data}, {custom_block})
+        #
+        # Unfortunately, we cannot guarantee that this is being called
+        # from the ScalarCustomBlock (someone could have inherited from
+        # that class to make another scalar class).  We will walk up the
+        # MRO to find the Scalar class (which should be the only class
+        # that has this Mixin as the first base class)
+        for cls in self.__class__.__mro__:
+            if cls.__bases__[0] is ScalarCustomBlockMixin:
+                _mixin, _data, _block = cls.__bases__
+                _data.__init__(self, component=self)
+                _block.__init__(self, *args, **kwargs)
+                break
 
 
 class CustomBlock(Block):
     """The base class used by instances of custom block components"""
 
-    def __init__(self, *args, **kwds):
+    def __init__(self, *args, **kwargs):
         if self._default_ctype is not None:
-            kwds.setdefault('ctype', self._default_ctype)
-        Block.__init__(self, *args, **kwds)
-
-    def __new__(cls, *args, **kwds):
-        if cls.__name__.startswith('_Indexed') or cls.__name__.startswith('_Scalar'):
-            # we are entering here the second time (recursive)
-            # therefore, we need to create what we have
-            return super(CustomBlock, cls).__new__(cls)
+            kwargs.setdefault('ctype', self._default_ctype)
+        Block.__init__(self, *args, **kwargs)
+
+    def __new__(cls, *args, **kwargs):
+        if cls.__bases__[0] is not CustomBlock:
+            # we are creating a class other than the "generic" derived
+            # custom block class.  We can assume that the routing of the
+            # generic block class to the specific Scalar or Indexed
+            # subclass has already occurred and we can pass control up
+            # to (toward) object.__new__()
+            return super().__new__(cls, *args, **kwargs)
+        # If the first base class is this CustomBlock class, then the
+        # user is attempting to create the "generic" block class.
+        # Depending on the arguments, we need to map this to either the
+        # Scalar or Indexed block subclass.
         if not args or (args[0] is UnindexedComponent_set and len(args) == 1):
-            n = _ScalarCustomBlockMeta(
-                "_Scalar%s" % (cls.__name__,), (cls._ComponentDataClass, cls), {}
-            )
-            return n.__new__(n)
+            return super().__new__(cls._scalar_custom_block, *args, **kwargs)
         else:
-            n = _IndexedCustomBlockMeta("_Indexed%s" % (cls.__name__,), (cls,), {})
-            return n.__new__(n)
+            return super().__new__(cls._indexed_custom_block, *args, **kwargs)
 
 
 def declare_custom_block(name, new_ctype=None):
     """Decorator to declare components for a custom block data class
 
-    >>> @declare_custom_block(name=FooBlock)
-    ... class FooBlockData(_BlockData):
+    >>> @declare_custom_block(name="FooBlock")
+    ... class FooBlockData(BlockData):
     ...    # custom block data class
     ...    pass
     """
 
-    def proc_dec(cls):
-        # this is the decorator function that
-        # creates the block component class
+    def block_data_decorator(block_data):
+        # this is the decorator function that creates the block
+        # component classes
 
-        # Default (derived) Block attributes
-        clsbody = {
-            "__module__": cls.__module__,  # magic to fix the module
-            # Default IndexedComponent data object is the decorated class:
-            "_ComponentDataClass": cls,
-            # By default this new block does not declare a new ctype
-            "_default_ctype": None,
-        }
-
-        c = type(
+        # Declare the new Block component (derived from CustomBlock)
+        # corresponding to the BlockData that we are decorating
+        #
+        # Note the use of `type(CustomBlock)` to pick up the metaclass
+        # that was used to create the CustomBlock (in general, it should
+        # be `type`)
+        comp = type(CustomBlock)(
             name,  # name of new class
             (CustomBlock,),  # base classes
-            clsbody,  # class body definitions (will populate __dict__)
+            # class body definitions (populate the new class' __dict__)
+            {
+                # ensure the created class is associated with the calling module
+                "__module__": block_data.__module__,
+                # Default IndexedComponent data object is the decorated class:
+                "_ComponentDataClass": block_data,
+                # By default this new block does not declare a new ctype
+                "_default_ctype": None,
+            },
         )
 
         if new_ctype is not None:
             if new_ctype is True:
-                c._default_ctype = c
-            elif type(new_ctype) is type:
-                c._default_ctype = new_ctype
+                comp._default_ctype = comp
+            elif isinstance(new_ctype, type):
+                comp._default_ctype = new_ctype
             else:
                 raise ValueError(
                     "Expected new_ctype to be either type "
                     "or 'True'; received: %s" % (new_ctype,)
                 )
 
-        # Register the new Block type in the same module as the BlockData
-        setattr(sys.modules[cls.__module__], name, c)
-        # TODO: can we also register concrete Indexed* and Scalar*
-        # classes into the original BlockData module (instead of relying
-        # on metaclasses)?
+        # Declare Indexed and Scalar versions of the custom block.  We
+        # will register them both with the calling module scope, and
+        # with the CustomBlock (so that CustomBlock.__new__ can route
+        # the object creation to the correct class)
+        comp._indexed_custom_block = type(comp)(
+            "Indexed" + name,
+            (comp,),
+            {  # ensure the created class is associated with the calling module
+                "__module__": block_data.__module__
+            },
+        )
+        comp._scalar_custom_block = type(comp)(
+            "Scalar" + name,
+            (ScalarCustomBlockMixin, block_data, comp),
+            {  # ensure the created class is associated with the calling module
+                "__module__": block_data.__module__
+            },
+        )
 
-        # are these necessary?
-        setattr(cls, '_orig_name', name)
-        setattr(cls, '_orig_module', cls.__module__)
-        return cls
+        # Register the new Block types in the same module as the BlockData
+        for _cls in (comp, comp._indexed_custom_block, comp._scalar_custom_block):
+            setattr(sys.modules[block_data.__module__], _cls.__name__, _cls)
+        return block_data
 
-    return proc_dec
+    return block_data_decorator
diff --git a/pyomo/core/base/blockutil.py b/pyomo/core/base/blockutil.py
index 21e6ac4db90..d91a5c85ac2 100644
--- a/pyomo/core/base/blockutil.py
+++ b/pyomo/core/base/blockutil.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -12,8 +12,6 @@
 # the purpose of this file is to collect all utility methods that compute
 # attributes of blocks, based on their contents.
 
-__all__ = ['has_discrete_variables']
-
 from pyomo.common import deprecated
 from pyomo.core.base import Var
 
diff --git a/pyomo/core/base/boolean_var.py b/pyomo/core/base/boolean_var.py
index 1945045abdd..db9a41fceda 100644
--- a/pyomo/core/base/boolean_var.py
+++ b/pyomo/core/base/boolean_var.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -68,27 +68,65 @@ def __setstate__(self, state):
         self._boolvar = weakref_ref(state)
 
 
-class _BooleanVarData(ComponentData, BooleanValue):
-    """
-    This class defines the data for a single variable.
-
-    Constructor Arguments:
-        component   The BooleanVar object that owns this data.
-    Public Class Attributes:
-        fixed       If True, then this variable is treated as a
-                        fixed constant in the model.
-        stale       A Boolean indicating whether the value of this variable is
-                        legitimate.  This value is true if the value should
-                        be considered legitimate for purposes of reporting or
-                        other interrogation.
-        value       The numeric value of this variable.
+def _associated_binary_mapper(encode, val):
+    if val is None:
+        return None
+    if encode:
+        if val.__class__ is not _DeprecatedImplicitAssociatedBinaryVariable:
+            return val()
+    else:
+        if val.__class__ is not _DeprecatedImplicitAssociatedBinaryVariable:
+            return weakref_ref(val)
+    return val
+
+
+class BooleanVarData(ComponentData, BooleanValue):
+    """This class defines the data for a single Boolean variable.
+
+    Parameters
+    ----------
+    component: Component
+        The BooleanVar object that owns this data.
+
+    Attributes
+    ----------
+    domain: SetData
+        The domain of this variable.
+
+    fixed: bool
+        If True, then this variable is treated as a fixed constant in
+        the model.
+
+    stale: bool
+        A Boolean indicating whether the value of this variable is
+        Consistent with the most recent solve.  `True` indicates that
+        this variable's value was set prior to the most recent solve and
+        was not updated by the results returned by the solve.
+
+    value: bool
+        The value of this variable.
     """
 
-    __slots__ = ()
+    __slots__ = ('_value', 'fixed', '_stale', '_associated_binary')
+    __autoslot_mappers__ = {
+        '_associated_binary': _associated_binary_mapper,
+        '_stale': StaleFlagManager.stale_mapper,
+    }
 
     def __init__(self, component=None):
+        #
+        # These lines represent in-lining of the
+        # following constructors:
+        #   - BooleanVarData
+        #   - ComponentData
+        #   - BooleanValue
         self._component = weakref_ref(component) if (component is not None) else None
         self._index = NOTSET
+        self._value = None
+        self.fixed = False
+        self._stale = 0  # True
+
+        self._associated_binary = None
 
     def is_fixed(self):
         """Returns True if this variable is fixed, otherwise returns False."""
@@ -132,113 +170,6 @@ def __call__(self, exception=True):
         """Compute the value of this variable."""
         return self.value
 
-    @property
-    def value(self):
-        """Return the value for this variable."""
-        raise NotImplementedError
-
-    @property
-    def domain(self):
-        """Return the domain for this variable."""
-        raise NotImplementedError
-
-    @property
-    def fixed(self):
-        """Return the fixed indicator for this variable."""
-        raise NotImplementedError
-
-    @property
-    def stale(self):
-        """Return the stale indicator for this variable."""
-        raise NotImplementedError
-
-    def fix(self, value=NOTSET, skip_validation=False):
-        """Fix the value of this variable (treat as nonvariable)
-
-        This sets the `fixed` indicator to True.  If ``value`` is
-        provided, the value (and the ``skip_validation`` flag) are first
-        passed to :py:meth:`set_value()`.
-
-        """
-        self.fixed = True
-        if value is not NOTSET:
-            self.set_value(value, skip_validation)
-
-    def unfix(self):
-        """Unfix this variable (treat as variable)
-
-        This sets the `fixed` indicator to False.
-
-        """
-        self.fixed = False
-
-    def free(self):
-        """Alias for :py:meth:`unfix`"""
-        return self.unfix()
-
-
-def _associated_binary_mapper(encode, val):
-    if val is None:
-        return None
-    if encode:
-        if val.__class__ is not _DeprecatedImplicitAssociatedBinaryVariable:
-            return val()
-    else:
-        if val.__class__ is not _DeprecatedImplicitAssociatedBinaryVariable:
-            return weakref_ref(val)
-    return val
-
-
-class _GeneralBooleanVarData(_BooleanVarData):
-    """
-    This class defines the data for a single Boolean variable.
-
-    Constructor Arguments:
-        component   The BooleanVar object that owns this data.
-
-    Public Class Attributes:
-        domain      The domain of this variable.
-        fixed       If True, then this variable is treated as a
-                        fixed constant in the model.
-        stale       A Boolean indicating whether the value of this variable is
-                        legitimiate.  This value is true if the value should
-                        be considered legitimate for purposes of reporting or
-                        other interrogation.
-        value       The numeric value of this variable.
-
-    The domain attribute is a property because it is
-    too widely accessed directly to enforce explicit getter/setter
-    methods and we need to deter directly modifying or accessing
-    these attributes in certain cases.
-    """
-
-    __slots__ = ('_value', 'fixed', '_stale', '_associated_binary')
-    __autoslot_mappers__ = {
-        '_associated_binary': _associated_binary_mapper,
-        '_stale': StaleFlagManager.stale_mapper,
-    }
-
-    def __init__(self, component=None):
-        #
-        # These lines represent in-lining of the
-        # following constructors:
-        #   - _BooleanVarData
-        #   - ComponentData
-        #   - BooleanValue
-        self._component = weakref_ref(component) if (component is not None) else None
-        self._index = NOTSET
-        self._value = None
-        self.fixed = False
-        self._stale = 0  # True
-
-        self._associated_binary = None
-
-    #
-    # Abstract Interface
-    #
-
-    # value is an attribute
-
     @property
     def value(self):
         """Return (or set) the value for this variable."""
@@ -265,14 +196,14 @@ def stale(self, val):
             self._stale = StaleFlagManager.get_flag(0)
 
     def get_associated_binary(self):
-        """Get the binary _VarData associated with this
-        _GeneralBooleanVarData"""
+        """Get the binary VarData associated with this
+        BooleanVarData"""
         return (
             self._associated_binary() if self._associated_binary is not None else None
         )
 
     def associate_binary_var(self, binary_var):
-        """Associate a binary _VarData to this _GeneralBooleanVarData"""
+        """Associate a binary VarData to this BooleanVarData"""
         if (
             self._associated_binary is not None
             and type(self._associated_binary)
@@ -294,6 +225,40 @@ def associate_binary_var(self, binary_var):
         if binary_var is not None:
             self._associated_binary = weakref_ref(binary_var)
 
+    def fix(self, value=NOTSET, skip_validation=False):
+        """Fix the value of this variable (treat as nonvariable)
+
+        This sets the `fixed` indicator to True.  If ``value`` is
+        provided, the value (and the ``skip_validation`` flag) are first
+        passed to :py:meth:`set_value()`.
+
+        """
+        self.fixed = True
+        if value is not NOTSET:
+            self.set_value(value, skip_validation)
+
+    def unfix(self):
+        """Unfix this variable (treat as variable)
+
+        This sets the `fixed` indicator to False.
+
+        """
+        self.fixed = False
+
+    def free(self):
+        """Alias for :py:meth:`unfix`"""
+        return self.unfix()
+
+
+class _BooleanVarData(metaclass=RenamedClass):
+    __renamed__new_class__ = BooleanVarData
+    __renamed__version__ = '6.7.2'
+
+
+class _GeneralBooleanVarData(metaclass=RenamedClass):
+    __renamed__new_class__ = BooleanVarData
+    __renamed__version__ = '6.7.2'
+
 
 @ModelComponentFactory.register("Logical decision variables.")
 class BooleanVar(IndexedComponent):
@@ -309,7 +274,7 @@ class BooleanVar(IndexedComponent):
             to True.
     """
 
-    _ComponentDataClass = _GeneralBooleanVarData
+    _ComponentDataClass = BooleanVarData
 
     def __new__(cls, *args, **kwds):
         if cls != BooleanVar:
@@ -385,8 +350,12 @@ def construct(self, data=None):
         timer = ConstructionTimer(self)
         self._constructed = True
 
+        if self._anonymous_sets is not None:
+            for _set in self._anonymous_sets:
+                _set.construct()
+
         #
-        # Construct _BooleanVarData objects for all index values
+        # Construct BooleanVarData objects for all index values
         #
         if not self.is_indexed():
             self._data[None] = self
@@ -497,11 +466,11 @@ def _pprint(self):
         )
 
 
-class ScalarBooleanVar(_GeneralBooleanVarData, BooleanVar):
+class ScalarBooleanVar(BooleanVarData, BooleanVar):
     """A single variable."""
 
     def __init__(self, *args, **kwd):
-        _GeneralBooleanVarData.__init__(self, component=self)
+        BooleanVarData.__init__(self, component=self)
         BooleanVar.__init__(self, *args, **kwd)
         self._index = UnindexedComponent_index
 
@@ -517,7 +486,7 @@ def __init__(self, *args, **kwd):
     def value(self):
         """Return the value for this variable."""
         if self._constructed:
-            return _GeneralBooleanVarData.value.fget(self)
+            return BooleanVarData.value.fget(self)
         raise ValueError(
             "Accessing the value of variable '%s' "
             "before the Var has been constructed (there "
@@ -528,7 +497,7 @@ def value(self):
     def value(self, val):
         """Set the value for this variable."""
         if self._constructed:
-            return _GeneralBooleanVarData.value.fset(self, val)
+            return BooleanVarData.value.fset(self, val)
         raise ValueError(
             "Setting the value of variable '%s' "
             "before the Var has been constructed (there "
@@ -537,7 +506,7 @@ def value(self, val):
 
     @property
     def domain(self):
-        return _GeneralBooleanVarData.domain.fget(self)
+        return BooleanVarData.domain.fget(self)
 
     def fix(self, value=NOTSET, skip_validation=False):
         """
@@ -545,7 +514,7 @@ def fix(self, value=NOTSET, skip_validation=False):
         indicating the variable should be fixed at its current value.
         """
         if self._constructed:
-            return _GeneralBooleanVarData.fix(self, value, skip_validation)
+            return BooleanVarData.fix(self, value, skip_validation)
         raise ValueError(
             "Fixing variable '%s' "
             "before the Var has been constructed (there "
@@ -555,7 +524,7 @@ def fix(self, value=NOTSET, skip_validation=False):
     def unfix(self):
         """Sets the fixed indicator to False."""
         if self._constructed:
-            return _GeneralBooleanVarData.unfix(self)
+            return BooleanVarData.unfix(self)
         raise ValueError(
             "Freeing variable '%s' "
             "before the Var has been constructed (there "
diff --git a/pyomo/core/base/check.py b/pyomo/core/base/check.py
index 0e9d8e889b2..485d1a73b6b 100644
--- a/pyomo/core/base/check.py
+++ b/pyomo/core/base/check.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,8 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['BuildCheck']
-
 import logging
 import types
 
diff --git a/pyomo/core/base/component.py b/pyomo/core/base/component.py
index bb855bd6f8d..966ce8c0737 100644
--- a/pyomo/core/base/component.py
+++ b/pyomo/core/base/component.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -20,6 +20,7 @@
 from pyomo.common.autoslots import AutoSlots, fast_deepcopy
 from pyomo.common.collections import OrderedDict
 from pyomo.common.deprecation import (
+    RenamedClass,
     deprecated,
     deprecation_warning,
     relocated_module_attribute,
@@ -79,7 +80,7 @@ class CloneError(pyomo.common.errors.PyomoException):
     pass
 
 
-class _ComponentBase(PyomoObject):
+class ComponentBase(PyomoObject):
     """A base class for Component and ComponentData
 
     This class defines some fundamental methods and properties that are
@@ -368,7 +369,7 @@ def pprint(self, ostream=None, verbose=False, prefix=""):
 
     @property
     def name(self):
-        """Get the fully qualifed component name."""
+        """Get the fully qualified component name."""
         return self.getname(fully_qualified=True)
 
     # Adding a setter here to help users adapt to the new
@@ -474,7 +475,12 @@ def _pprint_base_impl(
             ostream.write(_data)
 
 
-class Component(_ComponentBase):
+class _ComponentBase(metaclass=RenamedClass):
+    __renamed__new_class__ = ComponentBase
+    __renamed__version__ = '6.7.2'
+
+
+class Component(ComponentBase):
     """
     This is the base class for all Pyomo modeling components.
 
@@ -501,7 +507,7 @@ def __init__(self, **kwds):
         #
         self._ctype = kwds.pop('ctype', None)
         self.doc = kwds.pop('doc', None)
-        self._name = kwds.pop('name', str(type(self).__name__))
+        self._name = kwds.pop('name', None)
         if kwds:
             raise ValueError(
                 "Unexpected keyword options found while constructing '%s':\n\t%s"
@@ -625,6 +631,8 @@ def getname(self, fully_qualified=False, name_buffer=None, relative_to=None):
             Generate fully_qualified names relative to the specified block.
         """
         local_name = self._name
+        if local_name is None:
+            local_name = type(self).__name__
         if fully_qualified:
             pb = self.parent_block()
             if relative_to is None:
@@ -655,14 +663,14 @@ def getname(self, fully_qualified=False, name_buffer=None, relative_to=None):
                 "use of this argument poses risks if the buffer contains "
                 "names relative to different Blocks in the model hierarchy or "
                 "a mixture of local and fully_qualified names.",
-                version='TODO',
+                version='6.4.1',
             )
             name_buffer[id(self)] = ans
         return ans
 
     @property
     def name(self):
-        """Get the fully qualifed component name."""
+        """Get the fully qualified component name."""
         return self.getname(fully_qualified=True)
 
     # Allow setting a component's name if it is not owned by a parent
@@ -777,7 +785,7 @@ def deactivate(self):
         self._active = False
 
 
-class ComponentData(_ComponentBase):
+class ComponentData(ComponentBase):
     """
     This is the base class for the component data used
     in Pyomo modeling components.  Subclasses of ComponentData are
@@ -800,11 +808,11 @@ class ComponentData(_ComponentBase):
     __autoslot_mappers__ = {'_component': AutoSlots.weakref_mapper}
 
     # NOTE: This constructor is in-lined in the constructors for the following
-    # classes: _BooleanVarData, _ConnectorData, _ConstraintData,
-    # _GeneralExpressionData, _LogicalConstraintData,
-    # _GeneralLogicalConstraintData, _GeneralObjectiveData,
-    # _ParamData,_GeneralVarData, _GeneralBooleanVarData, _DisjunctionData,
-    # _ArcData, _PortData, _LinearConstraintData, and
+    # classes: BooleanVarData, ConnectorData, ConstraintData,
+    # ExpressionData, LogicalConstraintData,
+    # LogicalConstraintData, ObjectiveData,
+    # ParamData,VarData, BooleanVarData, DisjunctionData,
+    # ArcData, PortData, _LinearConstraintData, and
     # _LinearMatrixConstraintData. Changes made here need to be made in those
     # constructors as well!
     def __init__(self, component):
@@ -914,7 +922,7 @@ def getname(self, fully_qualified=False, name_buffer=None, relative_to=None):
                 "use of this argument poses risks if the buffer contains "
                 "names relative to different Blocks in the model hierarchy or "
                 "a mixture of local and fully_qualified names.",
-                version='TODO',
+                version='6.4.1',
             )
             if id(self) in name_buffer:
                 # Return the name if it is in the buffer
diff --git a/pyomo/core/base/component_namer.py b/pyomo/core/base/component_namer.py
index 17d46c12fae..c2fa01f6ad5 100644
--- a/pyomo/core/base/component_namer.py
+++ b/pyomo/core/base/component_namer.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/base/component_order.py b/pyomo/core/base/component_order.py
index 0685571ccb0..9244828cbe5 100644
--- a/pyomo/core/base/component_order.py
+++ b/pyomo/core/base/component_order.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,9 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-
-__all__ = ['items', 'display_items', 'display_name']
-
 from pyomo.core.base.set import Set, RangeSet
 from pyomo.core.base.param import Param
 from pyomo.core.base.var import Var
diff --git a/pyomo/core/base/componentuid.py b/pyomo/core/base/componentuid.py
index 89f7e5f8320..2075aa197dc 100644
--- a/pyomo/core/base/componentuid.py
+++ b/pyomo/core/base/componentuid.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/base/config.py b/pyomo/core/base/config.py
index 4c6cc06f90c..14c00522673 100644
--- a/pyomo/core/base/config.py
+++ b/pyomo/core/base/config.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/base/connector.py b/pyomo/core/base/connector.py
index f3d4833b837..1363f5abd65 100644
--- a/pyomo/core/base/connector.py
+++ b/pyomo/core/base/connector.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,8 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['Connector']
-
 import logging
 import sys
 from weakref import ref as weakref_ref
@@ -26,12 +24,11 @@
 from pyomo.core.base.global_set import UnindexedComponent_index
 from pyomo.core.base.indexed_component import IndexedComponent
 from pyomo.core.base.misc import apply_indexed_rule
-from pyomo.core.base.transformation import TransformationFactory
 
 logger = logging.getLogger('pyomo.core')
 
 
-class _ConnectorData(ComponentData, NumericValue):
+class ConnectorData(ComponentData, NumericValue):
     """Holds the actual connector information"""
 
     __slots__ = ('vars', 'aggregators')
@@ -108,6 +105,11 @@ def _iter_vars(self):
                     yield v
 
 
+class _ConnectorData(metaclass=RenamedClass):
+    __renamed__new_class__ = ConnectorData
+    __renamed__version__ = '6.7.2'
+
+
 @ModelComponentFactory.register(
     "A bundle of variables that can be manipulated together."
 )
@@ -160,7 +162,7 @@ def __init__(self, *args, **kwd):
     # IndexedComponent
     #
     def _getitem_when_not_present(self, idx):
-        _conval = self._data[idx] = _ConnectorData(component=self)
+        _conval = self._data[idx] = ConnectorData(component=self)
         return _conval
 
     def construct(self, data=None):
@@ -173,7 +175,7 @@ def construct(self, data=None):
         timer = ConstructionTimer(self)
         self._constructed = True
         #
-        # Construct _ConnectorData objects for all index values
+        # Construct ConnectorData objects for all index values
         #
         if self.is_indexed():
             self._initialize_members(self._index_set)
@@ -261,9 +263,9 @@ def _line_generator(k, v):
         )
 
 
-class ScalarConnector(Connector, _ConnectorData):
+class ScalarConnector(Connector, ConnectorData):
     def __init__(self, *args, **kwd):
-        _ConnectorData.__init__(self, component=self)
+        ConnectorData.__init__(self, component=self)
         Connector.__init__(self, *args, **kwd)
         self._index = UnindexedComponent_index
 
diff --git a/pyomo/core/base/constraint.py b/pyomo/core/base/constraint.py
index e391b4a5605..e12860991c2 100644
--- a/pyomo/core/base/constraint.py
+++ b/pyomo/core/base/constraint.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,20 +9,12 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = [
-    'Constraint',
-    '_ConstraintData',
-    'ConstraintList',
-    'simple_constraint_rule',
-    'simple_constraintlist_rule',
-]
-
-import io
+from __future__ import annotations
 import sys
 import logging
-import math
 from weakref import ref as weakref_ref
 from pyomo.common.pyomo_typing import overload
+from typing import Union, Type
 
 from pyomo.common.deprecation import RenamedClass
 from pyomo.common.errors import DeveloperError
@@ -37,6 +29,7 @@
     as_numeric,
     is_fixed,
     native_numeric_types,
+    native_logical_types,
     native_types,
 )
 from pyomo.core.expr import (
@@ -51,6 +44,7 @@
     ActiveIndexedComponent,
     UnindexedComponent_set,
     rule_wrapper,
+    IndexedComponent,
 )
 from pyomo.core.base.set import Set
 from pyomo.core.base.disable_methods import disable_methods
@@ -94,14 +88,15 @@ def C_rule(model, i, j):
 
     model.c = Constraint(rule=simple_constraint_rule(...))
     """
-    return rule_wrapper(
-        rule,
-        {
-            None: Constraint.Skip,
-            True: Constraint.Feasible,
-            False: Constraint.Infeasible,
-        },
-    )
+    map_types = set([type(None)]) | native_logical_types
+    result_map = {None: Constraint.Skip}
+    for l_type in native_logical_types:
+        result_map[l_type(True)] = Constraint.Feasible
+        result_map[l_type(False)] = Constraint.Infeasible
+    # Note: some logical types hash the same as bool (e.g., np.bool_), so
+    # we will pass the set of all logical types in addition to the
+    # result_map
+    return rule_wrapper(rule, result_map, map_types=map_types)
 
 
 def simple_constraintlist_rule(rule):
@@ -119,27 +114,24 @@ def C_rule(model, i, j):
 
     model.c = ConstraintList(expr=simple_constraintlist_rule(...))
     """
-    return rule_wrapper(
-        rule,
-        {
-            None: ConstraintList.End,
-            True: Constraint.Feasible,
-            False: Constraint.Infeasible,
-        },
-    )
-
-
-#
-# This class is a pure interface
-#
-
-
-class _ConstraintData(ActiveComponentData):
+    map_types = set([type(None)]) | native_logical_types
+    result_map = {None: ConstraintList.End}
+    for l_type in native_logical_types:
+        result_map[l_type(True)] = Constraint.Feasible
+        result_map[l_type(False)] = Constraint.Infeasible
+    # Note: some logical types hash the same as bool (e.g., np.bool_), so
+    # we will pass the set of all logical types in addition to the
+    # result_map
+    return rule_wrapper(rule, result_map, map_types=map_types)
+
+
+class ConstraintData(ActiveComponentData):
     """
-    This class defines the data for a single constraint.
+    This class defines the data for a single algebraic constraint.
 
     Constructor arguments:
         component       The Constraint object that owns this data.
+        expr            The Pyomo expression stored in this constraint.
 
     Public class attributes:
         active          A boolean that is true if this constraint is
@@ -159,164 +151,17 @@ class _ConstraintData(ActiveComponentData):
         _active         A boolean that indicates whether this data is active
     """
 
-    __slots__ = ()
+    __slots__ = ('_body', '_lower', '_upper', '_expr')
 
     # Set to true when a constraint class stores its expression
     # in linear canonical form
     _linear_canonical_form = False
 
-    def __init__(self, component=None):
-        #
-        # These lines represent in-lining of the
-        # following constructors:
-        #   - _ConstraintData,
-        #   - ActiveComponentData
-        #   - ComponentData
-        self._component = weakref_ref(component) if (component is not None) else None
-        self._index = NOTSET
-        self._active = True
-
-    #
-    # Interface
-    #
-
-    def __call__(self, exception=True):
-        """Compute the value of the body of this constraint."""
-        return value(self.body, exception=exception)
-
-    def has_lb(self):
-        """Returns :const:`False` when the lower bound is
-        :const:`None` or negative infinity"""
-        return self.lb is not None
-
-    def has_ub(self):
-        """Returns :const:`False` when the upper bound is
-        :const:`None` or positive infinity"""
-        return self.ub is not None
-
-    def lslack(self):
-        """
-        Returns the value of f(x)-L for constraints of the form:
-            L <= f(x) (<= U)
-            (U >=) f(x) >= L
-        """
-        lb = self.lb
-        if lb is None:
-            return _inf
-        else:
-            return value(self.body) - lb
-
-    def uslack(self):
-        """
-        Returns the value of U-f(x) for constraints of the form:
-            (L <=) f(x) <= U
-            U >= f(x) (>= L)
-        """
-        ub = self.ub
-        if ub is None:
-            return _inf
-        else:
-            return ub - value(self.body)
-
-    def slack(self):
-        """
-        Returns the smaller of lslack and uslack values
-        """
-        lb = self.lb
-        ub = self.ub
-        body = value(self.body)
-        if lb is None:
-            return ub - body
-        elif ub is None:
-            return body - lb
-        return min(ub - body, body - lb)
-
-    #
-    # Abstract Interface
-    #
-
-    @property
-    def body(self):
-        """Access the body of a constraint expression."""
-        raise NotImplementedError
-
-    @property
-    def lower(self):
-        """Access the lower bound of a constraint expression."""
-        raise NotImplementedError
-
-    @property
-    def upper(self):
-        """Access the upper bound of a constraint expression."""
-        raise NotImplementedError
-
-    @property
-    def lb(self):
-        """Access the value of the lower bound of a constraint expression."""
-        raise NotImplementedError
-
-    @property
-    def ub(self):
-        """Access the value of the upper bound of a constraint expression."""
-        raise NotImplementedError
-
-    @property
-    def equality(self):
-        """A boolean indicating whether this is an equality constraint."""
-        raise NotImplementedError
-
-    @property
-    def strict_lower(self):
-        """True if this constraint has a strict lower bound."""
-        raise NotImplementedError
-
-    @property
-    def strict_upper(self):
-        """True if this constraint has a strict upper bound."""
-        raise NotImplementedError
-
-    def set_value(self, expr):
-        """Set the expression on this constraint."""
-        raise NotImplementedError
-
-    def get_value(self):
-        """Get the expression on this constraint."""
-        raise NotImplementedError
-
-
-class _GeneralConstraintData(_ConstraintData):
-    """
-    This class defines the data for a single general constraint.
-
-    Constructor arguments:
-        component       The Constraint object that owns this data.
-        expr            The Pyomo expression stored in this constraint.
-
-    Public class attributes:
-        active          A boolean that is true if this constraint is
-                            active in the model.
-        body            The Pyomo expression for this constraint
-        lower           The Pyomo expression for the lower bound
-        upper           The Pyomo expression for the upper bound
-        equality        A boolean that indicates whether this is an
-                            equality constraint
-        strict_lower    A boolean that indicates whether this
-                            constraint uses a strict lower bound
-        strict_upper    A boolean that indicates whether this
-                            constraint uses a strict upper bound
-
-    Private class attributes:
-        _component      The objective component.
-        _active         A boolean that indicates whether this data is active
-    """
-
-    __slots__ = ('_body', '_lower', '_upper', '_expr')
-
     def __init__(self, expr=None, component=None):
         #
         # These lines represent in-lining of the
         # following constructors:
-        #   - _ConstraintData,
+        #   - ConstraintData,
         #   - ActiveComponentData
         #   - ComponentData
         self._component = weakref_ref(component) if (component is not None) else None
@@ -329,9 +174,9 @@ def __init__(self, expr=None, component=None):
         if expr is not None:
             self.set_value(expr)
 
-    #
-    # Abstract Interface
-    #
+    def __call__(self, exception=True):
+        """Compute the value of the body of this constraint."""
+        return value(self.body, exception=exception)
 
     @property
     def body(self):
@@ -455,6 +300,16 @@ def strict_upper(self):
         """True if this constraint has a strict upper bound."""
         return False
 
+    def has_lb(self):
+        """Returns :const:`False` when the lower bound is
+        :const:`None` or negative infinity"""
+        return self.lb is not None
+
+    def has_ub(self):
+        """Returns :const:`False` when the upper bound is
+        :const:`None` or positive infinity"""
+        return self.ub is not None
+
     @property
     def expr(self):
         """Return the expression associated with this constraint."""
@@ -682,6 +537,53 @@ def set_value(self, expr):
                         "upper bound (%s)." % (self.name, self._upper)
                     )
 
+    def lslack(self):
+        """
+        Returns the value of f(x)-L for constraints of the form:
+            L <= f(x) (<= U)
+            (U >=) f(x) >= L
+        """
+        lb = self.lb
+        if lb is None:
+            return _inf
+        else:
+            return value(self.body) - lb
+
+    def uslack(self):
+        """
+        Returns the value of U-f(x) for constraints of the form:
+            (L <=) f(x) <= U
+            U >= f(x) (>= L)
+        """
+        ub = self.ub
+        if ub is None:
+            return _inf
+        else:
+            return ub - value(self.body)
+
+    def slack(self):
+        """
+        Returns the smaller of lslack and uslack values
+        """
+        lb = self.lb
+        ub = self.ub
+        body = value(self.body)
+        if lb is None:
+            return ub - body
+        elif ub is None:
+            return body - lb
+        return min(ub - body, body - lb)
+
+
+class _ConstraintData(metaclass=RenamedClass):
+    __renamed__new_class__ = ConstraintData
+    __renamed__version__ = '6.7.2'
+
+
+class _GeneralConstraintData(metaclass=RenamedClass):
+    __renamed__new_class__ = ConstraintData
+    __renamed__version__ = '6.7.2'
+
 
 @ModelComponentFactory.register("General constraint expressions.")
 class Constraint(ActiveIndexedComponent):
@@ -717,8 +619,6 @@ class Constraint(ActiveIndexedComponent):
             A dictionary from the index set to component data objects
         _index
             The set of valid indices
-        _implicit_subsets
-            A tuple of set objects that represents the index set
         _model
             A weakref to the model that owns this component
         _parent
@@ -727,7 +627,7 @@ class Constraint(ActiveIndexedComponent):
             The class type for the derived subclass
     """
 
-    _ComponentDataClass = _GeneralConstraintData
+    _ComponentDataClass = ConstraintData
 
     class Infeasible(object):
         pass
@@ -737,6 +637,17 @@ class Infeasible(object):
     Violated = Infeasible
     Satisfied = Feasible
 
+    @overload
+    def __new__(
+        cls: Type[Constraint], *args, **kwds
+    ) -> Union[ScalarConstraint, IndexedConstraint]: ...
+
+    @overload
+    def __new__(cls: Type[ScalarConstraint], *args, **kwds) -> ScalarConstraint: ...
+
+    @overload
+    def __new__(cls: Type[IndexedConstraint], *args, **kwds) -> IndexedConstraint: ...
+
     def __new__(cls, *args, **kwds):
         if cls != Constraint:
             return super(Constraint, cls).__new__(cls)
@@ -771,6 +682,10 @@ def construct(self, data=None):
         if is_debug_set(logger):
             logger.debug("Constructing constraint %s" % (self.name))
 
+        if self._anonymous_sets is not None:
+            for _set in self._anonymous_sets:
+                _set.construct()
+
         rule = self.rule
         try:
             # We do not (currently) accept data for constructing Constraints
@@ -870,14 +785,14 @@ def display(self, prefix="", ostream=None):
         )
 
 
-class ScalarConstraint(_GeneralConstraintData, Constraint):
+class ScalarConstraint(ConstraintData, Constraint):
     """
     ScalarConstraint is the implementation representing a single,
     non-indexed constraint.
     """
 
     def __init__(self, *args, **kwds):
-        _GeneralConstraintData.__init__(self, component=self, expr=None)
+        ConstraintData.__init__(self, component=self, expr=None)
         Constraint.__init__(self, *args, **kwds)
         self._index = UnindexedComponent_index
 
@@ -888,7 +803,7 @@ def __init__(self, *args, **kwds):
     # currently in place). So during initialization only, we will
     # treat them as "indexed" objects where things like
     # Constraint.Skip are managed. But after that they will behave
-    # like _ConstraintData objects where set_value does not handle
+    # like ConstraintData objects where set_value does not handle
     # Constraint.Skip but expects a valid expression or None.
     #
     @property
@@ -901,7 +816,7 @@ def body(self):
                 "an expression. There is currently "
                 "nothing to access." % (self.name)
             )
-        return _GeneralConstraintData.body.fget(self)
+        return ConstraintData.body.fget(self)
 
     @property
     def lower(self):
@@ -913,7 +828,7 @@ def lower(self):
                 "an expression. There is currently "
                 "nothing to access." % (self.name)
             )
-        return _GeneralConstraintData.lower.fget(self)
+        return ConstraintData.lower.fget(self)
 
     @property
     def upper(self):
@@ -925,7 +840,7 @@ def upper(self):
                 "an expression. There is currently "
                 "nothing to access." % (self.name)
             )
-        return _GeneralConstraintData.upper.fget(self)
+        return ConstraintData.upper.fget(self)
 
     @property
     def equality(self):
@@ -937,7 +852,7 @@ def equality(self):
                 "an expression. There is currently "
                 "nothing to access." % (self.name)
             )
-        return _GeneralConstraintData.equality.fget(self)
+        return ConstraintData.equality.fget(self)
 
     @property
     def strict_lower(self):
@@ -949,7 +864,7 @@ def strict_lower(self):
                 "an expression. There is currently "
                 "nothing to access." % (self.name)
             )
-        return _GeneralConstraintData.strict_lower.fget(self)
+        return ConstraintData.strict_lower.fget(self)
 
     @property
     def strict_upper(self):
@@ -961,7 +876,7 @@ def strict_upper(self):
                 "an expression. There is currently "
                 "nothing to access." % (self.name)
             )
-        return _GeneralConstraintData.strict_upper.fget(self)
+        return ConstraintData.strict_upper.fget(self)
 
     def clear(self):
         self._data = {}
@@ -1025,6 +940,11 @@ def add(self, index, expr):
         """Add a constraint with a given index."""
         return self.__setitem__(index, expr)
 
+    @overload
+    def __getitem__(self, index) -> ConstraintData: ...
+
+    __getitem__ = IndexedComponent.__getitem__  # type: ignore
+
 
 @ModelComponentFactory.register("A list of constraint expressions.")
 class ConstraintList(IndexedConstraint):
@@ -1044,8 +964,7 @@ def __init__(self, **kwargs):
         _rule = kwargs.pop('rule', None)
         self._starting_index = kwargs.pop('starting_index', 1)
 
-        args = (Set(dimen=1),)
-        super(ConstraintList, self).__init__(*args, **kwargs)
+        super(ConstraintList, self).__init__(Set(dimen=1), **kwargs)
 
         self.rule = Initializer(
             _rule, treat_sequences_as_mappings=False, allow_generators=True
@@ -1067,7 +986,9 @@ def construct(self, data=None):
         if is_debug_set(logger):
             logger.debug("Constructing constraint list %s" % (self.name))
 
-        self.index_set().construct()
+        if self._anonymous_sets is not None:
+            for _set in self._anonymous_sets:
+                _set.construct()
 
         if self.rule is not None:
             _rule = self.rule(self.parent_block(), ())
diff --git a/pyomo/core/base/disable_methods.py b/pyomo/core/base/disable_methods.py
index 61d63d0a385..ff8eb98487a 100644
--- a/pyomo/core/base/disable_methods.py
+++ b/pyomo/core/base/disable_methods.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/base/enums.py b/pyomo/core/base/enums.py
index ddcc66fdc4e..31f2212a661 100644
--- a/pyomo/core/base/enums.py
+++ b/pyomo/core/base/enums.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/base/expression.py b/pyomo/core/base/expression.py
index 780bc17c8a3..a5120759236 100644
--- a/pyomo/core/base/expression.py
+++ b/pyomo/core/base/expression.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,15 +9,13 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['Expression', '_ExpressionData']
-
 import sys
 import logging
 from weakref import ref as weakref_ref
 from pyomo.common.pyomo_typing import overload
 
 from pyomo.common.log import is_debug_set
-from pyomo.common.deprecation import deprecated, RenamedClass
+from pyomo.common.deprecation import RenamedClass
 from pyomo.common.modeling import NOTSET
 from pyomo.common.formatting import tabular_writer
 from pyomo.common.timing import ConstructionTimer
@@ -32,31 +30,30 @@
 from pyomo.core.base.component import ComponentData, ModelComponentFactory
 from pyomo.core.base.global_set import UnindexedComponent_index
 from pyomo.core.base.indexed_component import IndexedComponent, UnindexedComponent_set
-from pyomo.core.base.misc import apply_indexed_rule
 from pyomo.core.expr.numvalue import as_numeric
 from pyomo.core.base.initializer import Initializer
 
 logger = logging.getLogger('pyomo.core')
 
 
-class _ExpressionData(numeric_expr.NumericValue):
-    """
-    An object that defines a named expression.
+class NamedExpressionData(numeric_expr.NumericValue):
+    """An object that defines a generic "named expression".
+
+    This is the base class for both :py:class:`ExpressionData` and
+    :py:class:`ObjectiveData`.
 
     Public Class Attributes
         expr       The expression owned by this data.
+
     """
 
+    # Note: derived classes are expected to declare the _args_ slot
     __slots__ = ()
 
     EXPRESSION_SYSTEM = EXPR.ExpressionType.NUMERIC
     PRECEDENCE = 0
     ASSOCIATIVITY = EXPR.OperatorAssociativity.NON_ASSOCIATIVE
 
-    #
-    # Interface
-    #
-
     def __call__(self, exception=True):
         """Compute the value of this expression."""
         (arg,) = self._args_
@@ -65,6 +62,18 @@ def __call__(self, exception=True):
             return arg
         return arg(exception=exception)
 
+    def create_node_with_local_data(self, values):
+        """
+        Construct a simple expression after constructing the
+        contained expression.
+
+        This class provides a consistent interface for constructing a
+        node, which is used in tree visitor scripts.
+        """
+        obj = self.__class__()
+        obj._args_ = values
+        return obj
+
     def is_named_expression_type(self):
         """A boolean indicating whether this in a named expression."""
         return True
@@ -113,9 +122,10 @@ def _compute_polynomial_degree(self, result):
     def _is_fixed(self, values):
         return values[0]
 
-    #
-    # Abstract Interface
-    #
+    # NamedExpressionData should never return False because
+    # they can store subexpressions that contain variables
+    def is_potentially_variable(self):
+        return True
 
     @property
     def expr(self):
@@ -128,58 +138,6 @@ def expr(self):
     def expr(self, value):
         self.set_value(value)
 
-    def set_value(self, expr):
-        """Set the expression on this expression."""
-        raise NotImplementedError
-
-    def is_constant(self):
-        """A boolean indicating whether this expression is constant."""
-        raise NotImplementedError
-
-    def is_fixed(self):
-        """A boolean indicating whether this expression is fixed."""
-        raise NotImplementedError
-
-    # _ExpressionData should never return False because
-    # they can store subexpressions that contain variables
-    def is_potentially_variable(self):
-        return True
-
-
-class _GeneralExpressionDataImpl(_ExpressionData):
-    """
-    An object that defines an expression that is never cloned
-
-    Constructor Arguments
-        expr        The Pyomo expression stored in this expression.
-        component   The Expression object that owns this data.
-
-    Public Class Attributes
-        expr       The expression owned by this data.
-    """
-
-    __slots__ = ()
-
-    def __init__(self, expr=None):
-        self._args_ = (expr,)
-
-    def create_node_with_local_data(self, values):
-        """
-        Construct a simple expression after constructing the
-        contained expression.
-
-        This class provides a consistent interface for constructing a
-        node, which is used in tree visitor scripts.
-        """
-        obj = ScalarExpression()
-        obj.construct()
-        obj._args_ = values
-        return obj
-
-    #
-    # Abstract Interface
-    #
-
     def set_value(self, expr):
         """Set the expression on this expression."""
         if expr is None or expr.__class__ in native_numeric_types:
@@ -238,7 +196,17 @@ def __ipow__(self, other):
         return numeric_expr._pow_dispatcher[e.__class__, other.__class__](e, other)
 
 
-class _GeneralExpressionData(_GeneralExpressionDataImpl, ComponentData):
+class _ExpressionData(metaclass=RenamedClass):
+    __renamed__new_class__ = NamedExpressionData
+    __renamed__version__ = '6.7.2'
+
+
+class _GeneralExpressionDataImpl(metaclass=RenamedClass):
+    __renamed__new_class__ = NamedExpressionData
+    __renamed__version__ = '6.7.2'
+
+
+class ExpressionData(NamedExpressionData, ComponentData):
     """
     An object that defines an expression that is never cloned
 
@@ -256,12 +224,16 @@ class _GeneralExpressionData(_GeneralExpressionDataImpl, ComponentData):
     __slots__ = ('_args_',)
 
     def __init__(self, expr=None, component=None):
-        _GeneralExpressionDataImpl.__init__(self, expr)
-        # Inlining ComponentData.__init__
+        self._args_ = (expr,)
         self._component = weakref_ref(component) if (component is not None) else None
         self._index = NOTSET
 
 
+class _GeneralExpressionData(metaclass=RenamedClass):
+    __renamed__new_class__ = ExpressionData
+    __renamed__version__ = '6.7.2'
+
+
 @ModelComponentFactory.register(
     "Named expressions that can be used in other expressions."
 )
@@ -278,7 +250,7 @@ class Expression(IndexedComponent):
         doc         Text describing this component.
     """
 
-    _ComponentDataClass = _GeneralExpressionData
+    _ComponentDataClass = ExpressionData
     # This seems like a copy-paste error, and should be renamed/removed
     NoConstraint = IndexedComponent.Skip
 
@@ -393,6 +365,10 @@ def construct(self, data=None):
                 % (self.name, str(data))
             )
 
+        if self._anonymous_sets is not None:
+            for _set in self._anonymous_sets:
+                _set.construct()
+
         try:
             # We do not (currently) accept data for constructing Constraints
             assert data is None
@@ -401,9 +377,9 @@ def construct(self, data=None):
             timer.report()
 
 
-class ScalarExpression(_GeneralExpressionData, Expression):
+class ScalarExpression(ExpressionData, Expression):
     def __init__(self, *args, **kwds):
-        _GeneralExpressionData.__init__(self, expr=None, component=self)
+        ExpressionData.__init__(self, expr=None, component=self)
         Expression.__init__(self, *args, **kwds)
         self._index = UnindexedComponent_index
 
@@ -426,7 +402,7 @@ def __call__(self, exception=True):
     def expr(self):
         """Return expression on this expression."""
         if self._constructed:
-            return _GeneralExpressionData.expr.fget(self)
+            return ExpressionData.expr.fget(self)
         raise ValueError(
             "Accessing the expression of Expression '%s' "
             "before the Expression has been constructed (there "
@@ -444,7 +420,7 @@ def clear(self):
     def set_value(self, expr):
         """Set the expression on this expression."""
         if self._constructed:
-            return _GeneralExpressionData.set_value(self, expr)
+            return ExpressionData.set_value(self, expr)
         raise ValueError(
             "Setting the expression of Expression '%s' "
             "before the Expression has been constructed (there "
@@ -454,7 +430,7 @@ def set_value(self, expr):
     def is_constant(self):
         """A boolean indicating whether this expression is constant."""
         if self._constructed:
-            return _GeneralExpressionData.is_constant(self)
+            return ExpressionData.is_constant(self)
         raise ValueError(
             "Accessing the is_constant flag of Expression '%s' "
             "before the Expression has been constructed (there "
@@ -464,7 +440,7 @@ def is_constant(self):
     def is_fixed(self):
         """A boolean indicating whether this expression is fixed."""
         if self._constructed:
-            return _GeneralExpressionData.is_fixed(self)
+            return ExpressionData.is_fixed(self)
         raise ValueError(
             "Accessing the is_fixed flag of Expression '%s' "
             "before the Expression has been constructed (there "
@@ -508,6 +484,6 @@ def add(self, index, expr):
         """Add an expression with a given index."""
         if (type(expr) is tuple) and (expr == Expression.Skip):
             return None
-        cdata = _GeneralExpressionData(expr, component=self)
+        cdata = ExpressionData(expr, component=self)
         self._data[index] = cdata
         return cdata
diff --git a/pyomo/core/base/external.py b/pyomo/core/base/external.py
index 93fb69e8cf7..0fda004b664 100644
--- a/pyomo/core/base/external.py
+++ b/pyomo/core/base/external.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -31,20 +31,18 @@
 
 from pyomo.common.autoslots import AutoSlots
 from pyomo.common.fileutils import find_library
-from pyomo.core.expr.numvalue import (
+from pyomo.common.numeric_types import (
+    check_if_native_type,
     native_types,
     native_numeric_types,
-    pyomo_constant_types,
-    NonNumericValue,
-    NumericConstant,
     value,
+    _pyomo_constant_types,
 )
+from pyomo.core.expr.numvalue import NonNumericValue, NumericConstant
 import pyomo.core.expr as EXPR
 from pyomo.core.base.component import Component
 from pyomo.core.base.units_container import units
 
-__all__ = ('ExternalFunction',)
-
 logger = logging.getLogger('pyomo.core')
 nan = float('nan')
 
@@ -199,14 +197,15 @@ def __call__(self, *args):
         pv = False
         for i, arg in enumerate(args_):
             try:
-                # Q: Is there a better way to test if a value is an object
-                #    not in native_types and not a standard expression type?
                 if arg.__class__ in native_types:
                     continue
                 if arg.is_potentially_variable():
                     pv = True
+                continue
             except AttributeError:
-                args_[i] = NonNumericValue(arg)
+                if check_if_native_type(arg):
+                    continue
+            args_[i] = NonNumericValue(arg)
         #
         if pv:
             return EXPR.ExternalFunctionExpression(args_, self)
@@ -493,7 +492,7 @@ def is_constant(self):
         return False
 
 
-pyomo_constant_types.add(_PythonCallbackFunctionID)
+_pyomo_constant_types.add(_PythonCallbackFunctionID)
 
 
 class PythonCallbackFunction(ExternalFunction):
diff --git a/pyomo/core/base/global_set.py b/pyomo/core/base/global_set.py
index f4d97403308..b1bb98abee0 100644
--- a/pyomo/core/base/global_set.py
+++ b/pyomo/core/base/global_set.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -72,8 +72,11 @@ def _parent(self, val):
 class _UnindexedComponent_set(GlobalSetBase):
     local_name = 'UnindexedComponent_set'
 
+    _anonymous_sets = GlobalSetBase
+
     def __init__(self, name):
         self.name = name
+        self._constructed = True
 
     def __contains__(self, val):
         return val is None
@@ -180,6 +183,12 @@ def prev(self, item, step=1):
     def prevw(self, item, step=1):
         return self.nextw(item, -step)
 
+    def parent_block(self):
+        return None
+
+    def parent_component(self):
+        return self
+
 
 UnindexedComponent_set = _UnindexedComponent_set('UnindexedComponent_set')
 GlobalSets[UnindexedComponent_set.local_name] = UnindexedComponent_set
diff --git a/pyomo/core/base/indexed_component.py b/pyomo/core/base/indexed_component.py
index 86b210331bb..37a62e5c4d7 100644
--- a/pyomo/core/base/indexed_component.py
+++ b/pyomo/core/base/indexed_component.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,21 +9,16 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['IndexedComponent', 'ActiveIndexedComponent']
-
-import enum
 import inspect
 import logging
 import sys
 import textwrap
 
-from copy import deepcopy
-
 import pyomo.core.expr as EXPR
 import pyomo.core.base as BASE
 from pyomo.core.base.indexed_component_slice import IndexedComponent_slice
 from pyomo.core.base.initializer import Initializer
-from pyomo.core.base.component import Component, ActiveComponent
+from pyomo.core.base.component import Component, ActiveComponent, ComponentData
 from pyomo.core.base.config import PyomoOptions
 from pyomo.core.base.enums import SortComponents
 from pyomo.core.base.global_set import UnindexedComponent_set
@@ -31,9 +26,9 @@
 from pyomo.core.pyomoobject import PyomoObject
 from pyomo.common import DeveloperError
 from pyomo.common.autoslots import fast_deepcopy
-from pyomo.common.dependencies import numpy as np, numpy_available
+from pyomo.common.collections import ComponentSet
 from pyomo.common.deprecation import deprecated, deprecation_warning
-from pyomo.common.errors import DeveloperError, TemplateExpressionError
+from pyomo.common.errors import TemplateExpressionError
 from pyomo.common.modeling import NOTSET
 from pyomo.common.numeric_types import native_types
 from pyomo.common.sorting import sorted_robust
@@ -165,9 +160,12 @@ def _get_indexed_component_data_name(component, index):
 """
 
 
-def rule_result_substituter(result_map):
+def rule_result_substituter(result_map, map_types):
     _map = result_map
-    _map_types = set(type(key) for key in result_map)
+    if map_types is None:
+        _map_types = set(type(key) for key in result_map)
+    else:
+        _map_types = map_types
 
     def rule_result_substituter_impl(rule, *args, **kwargs):
         if rule.__class__ in _map_types:
@@ -208,7 +206,7 @@ def rule_result_substituter_impl(rule, *args, **kwargs):
 """
 
 
-def rule_wrapper(rule, wrapping_fcn, positional_arg_map=None):
+def rule_wrapper(rule, wrapping_fcn, positional_arg_map=None, map_types=None):
     """Wrap a rule with another function
 
     This utility method provides a way to wrap a function (rule) with
@@ -235,7 +233,7 @@ def rule_wrapper(rule, wrapping_fcn, positional_arg_map=None):
 
     """
     if isinstance(wrapping_fcn, dict):
-        wrapping_fcn = rule_result_substituter(wrapping_fcn)
+        wrapping_fcn = rule_result_substituter(wrapping_fcn, map_types)
         if not inspect.isfunction(rule):
             return wrapping_fcn(rule)
     # Because some of our processing of initializer functions relies on
@@ -255,8 +253,7 @@ def rule_wrapper(rule, wrapping_fcn, positional_arg_map=None):
 
 
 class IndexedComponent(Component):
-    """
-    This is the base class for all indexed modeling components.
+    """This is the base class for all indexed modeling components.
     This class stores a dictionary, self._data, that maps indices
     to component data objects.  The object self._index_set defines valid
     keys for this dictionary, and the dictionary keys may be a
@@ -278,11 +275,16 @@ class IndexedComponent(Component):
         doc         A text string describing this component
 
     Private class attributes:
-        _data               A dictionary from the index set to
-                                component data objects
-        _index_set              The set of valid indices
-        _implicit_subsets   A temporary data element that stores
-                                sets that are transferred to the model
+
+        _data:  A dictionary from the index set to component data objects
+
+        _index_set:  The set of valid indices
+
+        _anonymous_sets: A ComponentSet of "anonymous" sets used by this
+            component.  Anonymous sets are Set / SetOperator / RangeSet
+            that compose attributes like _index_set, but are not
+            themselves explicitly assigned (and named) on any Block
+
     """
 
     class Skip(object):
@@ -304,37 +306,33 @@ def __init__(self, *args, **kwds):
         #
         self._data = {}
         #
-        if len(args) == 0 or (len(args) == 1 and args[0] is UnindexedComponent_set):
+        if len(args) == 0 or (args[0] is UnindexedComponent_set and len(args) == 1):
             #
             # If no indexing sets are provided, generate a dummy index
             #
-            self._implicit_subsets = None
             self._index_set = UnindexedComponent_set
+            self._anonymous_sets = None
         elif len(args) == 1:
             #
             # If a single indexing set is provided, just process it.
             #
-            self._implicit_subsets = None
-            self._index_set = BASE.set.process_setarg(args[0])
+            self._index_set, self._anonymous_sets = BASE.set.process_setarg(args[0])
         else:
             #
             # If multiple indexing sets are provided, process them all,
-            # and store the cross-product of these sets.  The individual
-            # sets need to stored in the Pyomo model, so the
-            # _implicit_subsets class data is used for this temporary
-            # storage.
+            # and store the cross-product of these sets.
             #
-            # Example:  Pyomo allows things like
-            # "Param([1,2,3], range(100), initialize=0)".  This
-            # needs to create *3* sets: two SetOf components and then
-            # the SetProduct.  That means that the component needs to
-            # hold on to the implicit SetOf objects until the component
-            # is assigned to a model (where the implicit subsets can be
-            # "transferred" to the model).
+            # Example: Pyomo allows things like "Param([1,2,3],
+            # range(100), initialize=0)".  This needs to create *3*
+            # sets: two SetOf components and then the SetProduct.  As
+            # the user declined to name any of these sets, we will not
+            # make up names and instead store them on the model as
+            # "anonymous components"
             #
-            tmp = [BASE.set.process_setarg(x) for x in args]
-            self._implicit_subsets = tmp
-            self._index_set = tmp[0].cross(*tmp[1:])
+            self._index_set = BASE.set.SetProduct(*args)
+            self._anonymous_sets = ComponentSet((self._index_set,))
+            if self._index_set._anonymous_sets is not None:
+                self._anonymous_sets.update(self._index_set._anonymous_sets)
 
     def _create_objects_for_deepcopy(self, memo, component_list):
         _new = self.__class__.__new__(self.__class__)
@@ -608,7 +606,7 @@ def iteritems(self):
         """Return a list (index,data) tuples from the dictionary"""
         return self.items()
 
-    def __getitem__(self, index):
+    def __getitem__(self, index) -> ComponentData:
         """
         This method returns the data corresponding to the given index.
         """
@@ -733,7 +731,7 @@ def __delitem__(self, index):
 
         # this supports "del m.x[:,1]" through a simple recursive call
         if index.__class__ is IndexedComponent_slice:
-            # Assert that this slice ws just generated
+            # Assert that this slice was just generated
             assert len(index._call_stack) == 1
             # Make a copy of the slicer items *before* we start
             # iterating over it (since we will be removing items!).
@@ -983,11 +981,13 @@ def _processUnhashableIndex(self, idx):
                 slice_dim -= 1
             if normalize_index.flatten:
                 set_dim = self.dim()
-            elif self._implicit_subsets is None:
+            elif not self.is_indexed():
                 # Scalar component.
                 set_dim = 0
             else:
-                set_dim = len(self._implicit_subsets)
+                set_dim = self.index_set().dimen
+                if set_dim is None:
+                    set_dim = 1
 
             structurally_valid = False
             if slice_dim == set_dim or set_dim is None:
diff --git a/pyomo/core/base/indexed_component_slice.py b/pyomo/core/base/indexed_component_slice.py
index 9779711a19b..37b3c452433 100644
--- a/pyomo/core/base/indexed_component_slice.py
+++ b/pyomo/core/base/indexed_component_slice.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -402,8 +402,7 @@ def __init__(self, component, fixed, sliced, ellipsis, iter_over_index, sort):
         self.last_index = ()
 
         self.tuplize_unflattened_index = (
-            self.component._implicit_subsets is None
-            or len(self.component._implicit_subsets) == 1
+            len(list(self.component.index_set().subsets())) <= 1
         )
 
         if fixed is None and sliced is None and ellipsis is None:
diff --git a/pyomo/core/base/initializer.py b/pyomo/core/base/initializer.py
index 991feb0450d..c87a4236abe 100644
--- a/pyomo/core/base/initializer.py
+++ b/pyomo/core/base/initializer.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/base/instance2dat.py b/pyomo/core/base/instance2dat.py
index b11c0c18e11..5cd690b7ece 100644
--- a/pyomo/core/base/instance2dat.py
+++ b/pyomo/core/base/instance2dat.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,8 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['instance2dat']
-
 import types
 from pyomo.core.base import Set, Param, value
 
diff --git a/pyomo/core/base/label.py b/pyomo/core/base/label.py
index b642b834146..e22c1283138 100644
--- a/pyomo/core/base/label.py
+++ b/pyomo/core/base/label.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,17 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = [
-    'CounterLabeler',
-    'NumericLabeler',
-    'CNameLabeler',
-    'TextLabeler',
-    'AlphaNumericTextLabeler',
-    'NameLabeler',
-    'CuidLabeler',
-    'ShortNameLabeler',
-]
-
 import re
 
 from pyomo.common.deprecation import deprecated
diff --git a/pyomo/core/base/logical_constraint.py b/pyomo/core/base/logical_constraint.py
index 6d553c66fed..cc0780fd9bd 100644
--- a/pyomo/core/base/logical_constraint.py
+++ b/pyomo/core/base/logical_constraint.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,8 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['LogicalConstraint', '_LogicalConstraintData', 'LogicalConstraintList']
-
 import inspect
 import sys
 import logging
@@ -22,7 +20,6 @@
 from pyomo.common.modeling import NOTSET
 from pyomo.common.timing import ConstructionTimer
 
-from pyomo.core.base.constraint import Constraint
 from pyomo.core.expr.boolean_value import as_boolean, BooleanConstant
 from pyomo.core.expr.numvalue import native_types, native_logical_types
 from pyomo.core.base.component import ActiveComponentData, ModelComponentFactory
@@ -45,64 +42,7 @@
 """
 
 
-class _LogicalConstraintData(ActiveComponentData):
-    """
-    This class defines the data for a single logical constraint.
-
-    It functions as a pure interface.
-
-    Constructor arguments:
-        component       The LogicalConstraint object that owns this data.
-
-    Public class attributes:
-        active          A boolean that is true if this statement is
-                            active in the model.
-        body            The Pyomo logical expression for this statement
-
-    Private class attributes:
-        _component      The statement component.
-        _active         A boolean that indicates whether this data is active
-    """
-
-    __slots__ = ()
-
-    def __init__(self, component=None):
-        #
-        # These lines represent in-lining of the
-        # following constructors:
-        #   - ActiveComponentData
-        #   - ComponentData
-        self._component = weakref_ref(component) if (component is not None) else None
-        self._index = NOTSET
-        self._active = True
-
-    #
-    # Interface
-    #
-    def __call__(self, exception=True):
-        """Compute the value of the body of this logical constraint."""
-        if self.body is None:
-            return None
-        return self.body(exception=exception)
-
-    #
-    # Abstract Interface
-    #
-    @property
-    def expr(self):
-        """Get the expression on this logical constraint."""
-        raise NotImplementedError
-
-    def set_value(self, expr):
-        """Set the expression on this logical constraint."""
-        raise NotImplementedError
-
-    def get_value(self):
-        """Get the expression on this logical constraint."""
-        raise NotImplementedError
-
-
-class _GeneralLogicalConstraintData(_LogicalConstraintData):
+class LogicalConstraintData(ActiveComponentData):
     """
     This class defines the data for a single general logical constraint.
 
@@ -126,7 +66,7 @@ def __init__(self, expr=None, component=None):
         #
         # These lines represent in-lining of the
         # following constructors:
-        #   - _LogicalConstraintData,
+        #   - LogicalConstraintData,
         #   - ActiveComponentData
         #   - ComponentData
         self._component = weakref_ref(component) if (component is not None) else None
@@ -137,6 +77,12 @@ def __init__(self, expr=None, component=None):
         if expr is not None:
             self.set_value(expr)
 
+    def __call__(self, exception=True):
+        """Compute the value of the body of this logical constraint."""
+        if self.body is None:
+            return None
+        return self.body(exception=exception)
+
     #
     # Abstract Interface
     #
@@ -176,6 +122,16 @@ def get_value(self):
         return self._expr
 
 
+class _LogicalConstraintData(metaclass=RenamedClass):
+    __renamed__new_class__ = LogicalConstraintData
+    __renamed__version__ = '6.7.2'
+
+
+class _GeneralLogicalConstraintData(metaclass=RenamedClass):
+    __renamed__new_class__ = LogicalConstraintData
+    __renamed__version__ = '6.7.2'
+
+
 @ModelComponentFactory.register("General logical constraints.")
 class LogicalConstraint(ActiveIndexedComponent):
     """
@@ -210,8 +166,6 @@ class LogicalConstraint(ActiveIndexedComponent):
             A dictionary from the index set to component data objects
         _index_set
             The set of valid indices
-        _implicit_subsets
-            A tuple of set objects that represents the index set
         _model
             A weakref to the model that owns this component
         _parent
@@ -220,7 +174,7 @@ class LogicalConstraint(ActiveIndexedComponent):
             The class type for the derived subclass
     """
 
-    _ComponentDataClass = _GeneralLogicalConstraintData
+    _ComponentDataClass = LogicalConstraintData
 
     class Infeasible(object):
         pass
@@ -280,6 +234,10 @@ def construct(self, data=None):
         timer = ConstructionTimer(self)
         self._constructed = True
 
+        if self._anonymous_sets is not None:
+            for _set in self._anonymous_sets:
+                _set.construct()
+
         _init_expr = self._init_expr
         _init_rule = self.rule
         #
@@ -374,7 +332,7 @@ def display(self, prefix="", ostream=None):
 
     #
     # Checks flags like Constraint.Skip, etc. before actually creating a
-    # constraint object. Returns the _ConstraintData object when it should be
+    # constraint object. Returns the ConstraintData object when it should be
     #  added to the _data dict; otherwise, None is returned or an exception
     # is raised.
     #
@@ -410,14 +368,14 @@ def _check_skip_add(self, index, expr):
         return expr
 
 
-class ScalarLogicalConstraint(_GeneralLogicalConstraintData, LogicalConstraint):
+class ScalarLogicalConstraint(LogicalConstraintData, LogicalConstraint):
     """
     ScalarLogicalConstraint is the implementation representing a single,
     non-indexed logical constraint.
     """
 
     def __init__(self, *args, **kwds):
-        _GeneralLogicalConstraintData.__init__(self, component=self, expr=None)
+        LogicalConstraintData.__init__(self, component=self, expr=None)
         LogicalConstraint.__init__(self, *args, **kwds)
         self._index = UnindexedComponent_index
 
@@ -437,7 +395,7 @@ def body(self):
                     "an expression. There is currently "
                     "nothing to access." % self.name
                 )
-            return _GeneralLogicalConstraintData.body.fget(self)
+            return LogicalConstraintData.body.fget(self)
         raise ValueError(
             "Accessing the body of logical constraint '%s' "
             "before the LogicalConstraint has been constructed (there "
@@ -451,7 +409,7 @@ def body(self):
     # currently in place). So during initialization only, we will
     # treat them as "indexed" objects where things like
     # True are managed. But after that they will behave
-    # like _LogicalConstraintData objects where set_value expects
+    # like LogicalConstraintData objects where set_value expects
     # a valid expression or None.
     #
 
@@ -516,22 +474,25 @@ class LogicalConstraintList(IndexedLogicalConstraint):
 
     def __init__(self, **kwargs):
         """Constructor"""
-        args = (Set(),)
         if 'expr' in kwargs:
             raise ValueError("LogicalConstraintList does not accept the 'expr' keyword")
-        LogicalConstraint.__init__(self, *args, **kwargs)
+        LogicalConstraint.__init__(self, Set(dimen=1), **kwargs)
 
     def construct(self, data=None):
         """
         Construct the expression(s) for this logical constraint.
         """
+        if self._constructed:
+            return
+        self._constructed = True
+
         generate_debug_messages = is_debug_set(logger)
         if generate_debug_messages:
             logger.debug("Constructing logical constraint list %s" % self.name)
 
-        if self._constructed:
-            return
-        self._constructed = True
+        if self._anonymous_sets is not None:
+            for _set in self._anonymous_sets:
+                _set.construct()
 
         assert self._init_expr is None
         _init_rule = self.rule
diff --git a/pyomo/core/base/matrix_constraint.py b/pyomo/core/base/matrix_constraint.py
index 0c55dbc15d3..8dac7c3d24b 100644
--- a/pyomo/core/base/matrix_constraint.py
+++ b/pyomo/core/base/matrix_constraint.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -19,7 +19,7 @@
 from pyomo.core.expr.numvalue import value
 from pyomo.core.expr.numeric_expr import LinearExpression
 from pyomo.core.base.component import ModelComponentFactory
-from pyomo.core.base.constraint import IndexedConstraint, _ConstraintData
+from pyomo.core.base.constraint import IndexedConstraint, ConstraintData
 from pyomo.repn.standard_repn import StandardRepn
 
 from collections.abc import Mapping
@@ -28,7 +28,7 @@
 logger = logging.getLogger('pyomo.core')
 
 
-class _MatrixConstraintData(_ConstraintData):
+class _MatrixConstraintData(ConstraintData):
     """
     This class defines the data for a single linear constraint
         derived from a canonical form Ax=b constraint.
@@ -104,7 +104,7 @@ def __init__(self, index, component_ref):
         #
         # These lines represent in-lining of the
         # following constructors:
-        #   - _ConstraintData,
+        #   - ConstraintData,
         #   - ActiveComponentData
         #   - ComponentData
         self._component = component_ref
@@ -209,7 +209,7 @@ def index(self):
         return self._index
 
     #
-    # Abstract Interface (_ConstraintData)
+    # Abstract Interface (ConstraintData)
     #
 
     @property
diff --git a/pyomo/core/base/misc.py b/pyomo/core/base/misc.py
index cf37ad48fea..456a4531e30 100644
--- a/pyomo/core/base/misc.py
+++ b/pyomo/core/base/misc.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,14 +9,10 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['display']
-
 import logging
 import sys
-import types
 
 from pyomo.common.deprecation import relocated_module_attribute
-from pyomo.core.expr import native_numeric_types
 
 logger = logging.getLogger('pyomo.core')
 
diff --git a/pyomo/core/base/numvalue.py b/pyomo/core/base/numvalue.py
index 11d45228bf5..75bceef7ebb 100644
--- a/pyomo/core/base/numvalue.py
+++ b/pyomo/core/base/numvalue.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/base/objective.py b/pyomo/core/base/objective.py
index 7fb495f3e5b..f1204f2a09c 100644
--- a/pyomo/core/base/objective.py
+++ b/pyomo/core/base/objective.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,22 +9,13 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = (
-    'Objective',
-    'simple_objective_rule',
-    '_ObjectiveData',
-    'minimize',
-    'maximize',
-    'simple_objectivelist_rule',
-    'ObjectiveList',
-)
-
 import sys
 import logging
 from weakref import ref as weakref_ref
 from pyomo.common.pyomo_typing import overload
 
 from pyomo.common.deprecation import RenamedClass
+from pyomo.common.enums import ObjectiveSense, minimize, maximize
 from pyomo.common.log import is_debug_set
 from pyomo.common.modeling import NOTSET
 from pyomo.common.formatting import tabular_writer
@@ -38,14 +29,13 @@
     UnindexedComponent_set,
     rule_wrapper,
 )
-from pyomo.core.base.expression import _ExpressionData, _GeneralExpressionDataImpl
+from pyomo.core.base.expression import NamedExpressionData
 from pyomo.core.base.set import Set
 from pyomo.core.base.initializer import (
     Initializer,
     IndexedCallInitializer,
     CountedCallInitializer,
 )
-from pyomo.core.base import minimize, maximize
 
 logger = logging.getLogger('pyomo.core')
 
@@ -91,47 +81,7 @@ def O_rule(model, i, j):
     return rule_wrapper(rule, {None: ObjectiveList.End})
 
 
-#
-# This class is a pure interface
-#
-
-
-class _ObjectiveData(_ExpressionData):
-    """
-    This class defines the data for a single objective.
-
-    Public class attributes:
-        expr            The Pyomo expression for this objective
-        sense           The direction for this objective.
-    """
-
-    __slots__ = ()
-
-    #
-    # Interface
-    #
-
-    def is_minimizing(self):
-        """Return True if this is a minimization objective."""
-        return self.sense == minimize
-
-    #
-    # Abstract Interface
-    #
-
-    @property
-    def sense(self):
-        """Access sense (direction) of this objective."""
-        raise NotImplementedError
-
-    def set_sense(self, sense):
-        """Set the sense (direction) of this objective."""
-        raise NotImplementedError
-
-
-class _GeneralObjectiveData(
-    _GeneralExpressionDataImpl, _ObjectiveData, ActiveComponentData
-):
+class ObjectiveData(NamedExpressionData, ActiveComponentData):
     """
     This class defines the data for a single objective.
 
@@ -154,22 +104,20 @@ class _GeneralObjectiveData(
         _active         A boolean that indicates whether this data is active
     """
 
-    __slots__ = ("_sense", "_args_")
+    __slots__ = ("_args_", "_sense")
 
     def __init__(self, expr=None, sense=minimize, component=None):
-        _GeneralExpressionDataImpl.__init__(self, expr)
+        # Inlining NamedExpressionData.__init__
+        self._args_ = (expr,)
         # Inlining ActiveComponentData.__init__
         self._component = weakref_ref(component) if (component is not None) else None
         self._index = NOTSET
         self._active = True
-        self._sense = sense
+        self._sense = ObjectiveSense(sense)
 
-        if (self._sense != minimize) and (self._sense != maximize):
-            raise ValueError(
-                "Objective sense must be set to one of "
-                "'minimize' (%s) or 'maximize' (%s). Invalid "
-                "value: %s'" % (minimize, maximize, sense)
-            )
+    def is_minimizing(self):
+        """Return True if this is a minimization objective."""
+        return self.sense == minimize
 
     def set_value(self, expr):
         if expr is None:
@@ -192,14 +140,17 @@ def sense(self, sense):
 
     def set_sense(self, sense):
         """Set the sense (direction) of this objective."""
-        if sense in {minimize, maximize}:
-            self._sense = sense
-        else:
-            raise ValueError(
-                "Objective sense must be set to one of "
-                "'minimize' (%s) or 'maximize' (%s). Invalid "
-                "value: %s'" % (minimize, maximize, sense)
-            )
+        self._sense = ObjectiveSense(sense)
+
+
+class _ObjectiveData(metaclass=RenamedClass):
+    __renamed__new_class__ = ObjectiveData
+    __renamed__version__ = '6.7.2'
+
+
+class _GeneralObjectiveData(metaclass=RenamedClass):
+    __renamed__new_class__ = ObjectiveData
+    __renamed__version__ = '6.7.2'
 
 
 @ModelComponentFactory.register("Expressions that are minimized or maximized.")
@@ -242,8 +193,6 @@ class Objective(ActiveIndexedComponent):
             A dictionary from the index set to component data objects
         _index
             The set of valid indices
-        _implicit_subsets
-            A tuple of set objects that represents the index set
         _model
             A weakref to the model that owns this component
         _parent
@@ -252,7 +201,7 @@ class Objective(ActiveIndexedComponent):
             The class type for the derived subclass
     """
 
-    _ComponentDataClass = _GeneralObjectiveData
+    _ComponentDataClass = ObjectiveData
     NoObjective = ActiveIndexedComponent.Skip
 
     def __new__(cls, *args, **kwds):
@@ -290,6 +239,10 @@ def construct(self, data=None):
         if is_debug_set(logger):
             logger.debug("Constructing objective %s" % (self.name))
 
+        if self._anonymous_sets is not None:
+            for _set in self._anonymous_sets:
+                _set.construct()
+
         rule = self.rule
         try:
             # We do not (currently) accept data for constructing Objectives
@@ -361,11 +314,7 @@ def _pprint(self):
             ],
             self._data.items(),
             ("Active", "Sense", "Expression"),
-            lambda k, v: [
-                v.active,
-                ("minimize" if (v.sense == minimize) else "maximize"),
-                v.expr,
-            ],
+            lambda k, v: [v.active, v.sense, v.expr],
         )
 
     def display(self, prefix="", ostream=None):
@@ -397,14 +346,14 @@ def display(self, prefix="", ostream=None):
         )
 
 
-class ScalarObjective(_GeneralObjectiveData, Objective):
+class ScalarObjective(ObjectiveData, Objective):
     """
     ScalarObjective is the implementation representing a single,
     non-indexed objective.
     """
 
     def __init__(self, *args, **kwd):
-        _GeneralObjectiveData.__init__(self, expr=None, component=self)
+        ObjectiveData.__init__(self, expr=None, component=self)
         Objective.__init__(self, *args, **kwd)
         self._index = UnindexedComponent_index
 
@@ -440,7 +389,7 @@ def expr(self):
                     "a sense or expression (there is currently "
                     "no value to return)." % (self.name)
                 )
-            return _GeneralObjectiveData.expr.fget(self)
+            return ObjectiveData.expr.fget(self)
         raise ValueError(
             "Accessing the expression of objective '%s' "
             "before the Objective has been constructed (there "
@@ -463,7 +412,7 @@ def sense(self):
                     "a sense or expression (there is currently "
                     "no value to return)." % (self.name)
                 )
-            return _GeneralObjectiveData.sense.fget(self)
+            return ObjectiveData.sense.fget(self)
         raise ValueError(
             "Accessing the sense of objective '%s' "
             "before the Objective has been constructed (there "
@@ -482,7 +431,7 @@ def sense(self, sense):
     # currently in place). So during initialization only, we will
     # treat them as "indexed" objects where things like
     # Objective.Skip are managed. But after that they will behave
-    # like _ObjectiveData objects where set_value does not handle
+    # like ObjectiveData objects where set_value does not handle
     # Objective.Skip but expects a valid expression or None
     #
 
@@ -506,7 +455,7 @@ def set_sense(self, sense):
         if self._constructed:
             if len(self._data) == 0:
                 self._data[None] = self
-            return _GeneralObjectiveData.set_sense(self, sense)
+            return ObjectiveData.set_sense(self, sense)
         raise ValueError(
             "Setting the sense of objective '%s' "
             "before the Objective has been constructed (there "
@@ -564,8 +513,7 @@ def __init__(self, **kwargs):
         _rule = kwargs.pop('rule', None)
         self._starting_index = kwargs.pop('starting_index', 1)
 
-        args = (Set(dimen=1),)
-        super().__init__(*args, **kwargs)
+        super().__init__(Set(dimen=1), **kwargs)
 
         self.rule = Initializer(_rule, allow_generators=True)
         # HACK to make the "counted call" syntax work.  We wait until
@@ -585,7 +533,9 @@ def construct(self, data=None):
         if is_debug_set(logger):
             logger.debug("Constructing objective list %s" % (self.name))
 
-        self.index_set().construct()
+        if self._anonymous_sets is not None:
+            for _set in self._anonymous_sets:
+                _set.construct()
 
         if self.rule is not None:
             _rule = self.rule(self.parent_block(), ())
diff --git a/pyomo/core/base/param.py b/pyomo/core/base/param.py
index ea4290d880d..45de3286589 100644
--- a/pyomo/core/base/param.py
+++ b/pyomo/core/base/param.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,13 +9,13 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['Param']
-
+from __future__ import annotations
 import sys
 import types
 import logging
 from weakref import ref as weakref_ref
 from pyomo.common.pyomo_typing import overload
+from typing import Union, Type
 
 from pyomo.common.autoslots import AutoSlots
 from pyomo.common.deprecation import deprecation_warning, RenamedClass
@@ -118,7 +118,7 @@ def _parent(self, val):
         pass
 
 
-class _ParamData(ComponentData, NumericValue):
+class ParamData(ComponentData, NumericValue):
     """
     This class defines the data for a mutable parameter.
 
@@ -164,16 +164,31 @@ def set_value(self, value, idx=NOTSET):
         # required to be mutable.
         #
         _comp = self.parent_component()
-        if type(value) in native_types:
+        if value.__class__ in native_types:
             # TODO: warn/error: check if this Param has units: assigning
             # a dimensionless value to a united param should be an error
             pass
         elif _comp._units is not None:
             _src_magnitude = expr_value(value)
-            _src_units = units.get_units(value)
-            value = units.convert_value(
-                num_value=_src_magnitude, from_units=_src_units, to_units=_comp._units
-            )
+            # Note: expr_value() could have just registered a new numeric type
+            if value.__class__ in native_types:
+                value = _src_magnitude
+            else:
+                _src_units = units.get_units(value)
+                value = units.convert_value(
+                    num_value=_src_magnitude,
+                    from_units=_src_units,
+                    to_units=_comp._units,
+                )
+        # FIXME: we should call value() here [to ensure types get
+        # registered], but doing so breaks non-numeric Params (which we
+        # allow).  The real fix will be to follow the precedent from
+        # GetItemExpression and have separate types based on which
+        # expression "system" the Param should participate in (numeric,
+        # logical, or structural).
+        #
+        # else:
+        #     value = expr_value(value)
 
         old_value, self._value = self._value, value
         try:
@@ -237,6 +252,11 @@ def _compute_polynomial_degree(self, result):
         return 0
 
 
+class _ParamData(metaclass=RenamedClass):
+    __renamed__new_class__ = ParamData
+    __renamed__version__ = '6.7.2'
+
+
 @ModelComponentFactory.register(
     "Parameter data that is used to define a model instance."
 )
@@ -270,7 +290,7 @@ class Param(IndexedComponent, IndexedComponent_NDArrayMixin):
     """
 
     DefaultMutable = False
-    _ComponentDataClass = _ParamData
+    _ComponentDataClass = ParamData
 
     class NoValue(object):
         """A dummy type that is pickle-safe that we can use as the default
@@ -278,6 +298,17 @@ class NoValue(object):
 
         pass
 
+    @overload
+    def __new__(
+        cls: Type[Param], *args, **kwds
+    ) -> Union[ScalarParam, IndexedParam]: ...
+
+    @overload
+    def __new__(cls: Type[ScalarParam], *args, **kwds) -> ScalarParam: ...
+
+    @overload
+    def __new__(cls: Type[IndexedParam], *args, **kwds) -> IndexedParam: ...
+
     def __new__(cls, *args, **kwds):
         if cls != Param:
             return super(Param, cls).__new__(cls)
@@ -330,7 +361,7 @@ def __init__(self, *args, **kwd):
         if _domain_rule is None:
             self.domain = _ImplicitAny(owner=self, name='Any')
         else:
-            self.domain = SetInitializer(_domain_rule)(self.parent_block(), None)
+            self.domain = SetInitializer(_domain_rule)(self.parent_block(), None, self)
         # After IndexedComponent.__init__ so we can call is_indexed().
         self._rule = Initializer(
             _init,
@@ -497,14 +528,14 @@ def store_values(self, new_values, check=True):
                 # instead of incurring the penalty of checking.
                 for index, new_value in new_values.items():
                     if index not in self._data:
-                        self._data[index] = _ParamData(self)
+                        self._data[index] = ParamData(self)
                     self._data[index]._value = new_value
             else:
                 # For scalars, we will choose an approach based on
                 # how "dense" the Param is
                 if not self._data:  # empty
                     for index in self._index_set:
-                        p = self._data[index] = _ParamData(self)
+                        p = self._data[index] = ParamData(self)
                         p._value = new_values
                 elif len(self._data) == len(self._index_set):
                     for index in self._index_set:
@@ -512,7 +543,7 @@ def store_values(self, new_values, check=True):
                 else:
                     for index in self._index_set:
                         if index not in self._data:
-                            self._data[index] = _ParamData(self)
+                            self._data[index] = ParamData(self)
                         self._data[index]._value = new_values
         else:
             #
@@ -575,9 +606,9 @@ def _getitem_when_not_present(self, index):
             # a default value, as long as *solving* a model without
             # reasonable values produces an informative error.
             if self._mutable:
-                # Note: _ParamData defaults to Param.NoValue
+                # Note: ParamData defaults to Param.NoValue
                 if self.is_indexed():
-                    ans = self._data[index] = _ParamData(self)
+                    ans = self._data[index] = ParamData(self)
                 else:
                     ans = self._data[index] = self
                 ans._index = index
@@ -672,8 +703,8 @@ def _setitem_impl(self, index, obj, value):
             return obj
         else:
             old_value, self._data[index] = self._data[index], value
-            # Because we do not have a _ParamData, we cannot rely on the
-            # validation that occurs in _ParamData.set_value()
+            # Because we do not have a ParamData, we cannot rely on the
+            # validation that occurs in ParamData.set_value()
             try:
                 self._validate_value(index, value)
                 return value
@@ -710,14 +741,14 @@ def _setitem_when_not_present(self, index, value, _check_domain=True):
                 self._index = UnindexedComponent_index
                 return self
             elif self._mutable:
-                obj = self._data[index] = _ParamData(self)
+                obj = self._data[index] = ParamData(self)
                 obj.set_value(value, index)
                 obj._index = index
                 return obj
             else:
                 self._data[index] = value
-                # Because we do not have a _ParamData, we cannot rely on the
-                # validation that occurs in _ParamData.set_value()
+                # Because we do not have a ParamData, we cannot rely on the
+                # validation that occurs in ParamData.set_value()
                 self._validate_value(index, value, _check_domain)
                 return value
         except:
@@ -783,6 +814,10 @@ def construct(self, data=None):
                 )
                 self._mutable = True
 
+        if self._anonymous_sets is not None:
+            for _set in self._anonymous_sets:
+                _set.construct()
+
         try:
             #
             # If the default value is a simple type, we check it versus
@@ -871,9 +906,9 @@ def _pprint(self):
         return (headers, self.sparse_iteritems(), ("Value",), dataGen)
 
 
-class ScalarParam(_ParamData, Param):
+class ScalarParam(ParamData, Param):
     def __init__(self, *args, **kwds):
-        _ParamData.__init__(self, component=self)
+        ParamData.__init__(self, component=self)
         Param.__init__(self, *args, **kwds)
         self._index = UnindexedComponent_index
 
@@ -966,7 +1001,7 @@ def _create_objects_for_deepcopy(self, memo, component_list):
     # between potentially variable GetItemExpression objects and
     # "constant" GetItemExpression objects.  That will need to wait for
     # the expression rework [JDS; Nov 22].
-    def __getitem__(self, args):
+    def __getitem__(self, args) -> ParamData:
         try:
             return super().__getitem__(args)
         except:
diff --git a/pyomo/core/base/piecewise.py b/pyomo/core/base/piecewise.py
index ef2fb9eefae..8c5f34d2b53 100644
--- a/pyomo/core/base/piecewise.py
+++ b/pyomo/core/base/piecewise.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -32,9 +32,6 @@
 *) piecewise for functions of the form y = f(x1,x2,...)
 """
 
-
-__all__ = ['Piecewise']
-
 import logging
 import math
 import itertools
@@ -43,14 +40,14 @@
 import enum
 
 from pyomo.common.log import is_debug_set
-from pyomo.common.deprecation import deprecation_warning
+from pyomo.common.deprecation import RenamedClass, deprecation_warning
 from pyomo.common.numeric_types import value
 from pyomo.common.timing import ConstructionTimer
-from pyomo.core.base.block import Block, _BlockData
+from pyomo.core.base.block import Block, BlockData
 from pyomo.core.base.component import ModelComponentFactory
 from pyomo.core.base.constraint import Constraint, ConstraintList
 from pyomo.core.base.sos import SOSConstraint
-from pyomo.core.base.var import Var, _VarData, IndexedVar
+from pyomo.core.base.var import Var, VarData, IndexedVar
 from pyomo.core.base.set_types import PositiveReals, NonNegativeReals, Binary
 from pyomo.core.base.util import flatten_tuple
 
@@ -217,14 +214,14 @@ def _characterize_function(name, tol, f_rule, model, points, *index):
     return 0, values, False
 
 
-class _PiecewiseData(_BlockData):
+class PiecewiseData(BlockData):
     """
     This class defines the base class for all linearization
     and piecewise constraint generators..
     """
 
     def __init__(self, parent):
-        _BlockData.__init__(self, parent)
+        BlockData.__init__(self, parent)
         self._constructed = True
         self._bound_type = None
         self._domain_pts = None
@@ -275,6 +272,11 @@ def __call__(self, x):
         )
 
 
+class _PiecewiseData(metaclass=RenamedClass):
+    __renamed__new_class__ = PiecewiseData
+    __renamed__version__ = '6.7.2'
+
+
 class _SimpleSinglePiecewise(object):
     """
     Called when the piecewise points list has only two points
@@ -1128,7 +1130,7 @@ def f(model,j,x):
                       not be modified.
     """
 
-    _ComponentDataClass = _PiecewiseData
+    _ComponentDataClass = PiecewiseData
 
     def __new__(cls, *args, **kwds):
         if cls != Piecewise:
@@ -1238,7 +1240,7 @@ def __init__(self, *args, **kwds):
 
         # Check that the variables args are actually Pyomo Vars
         if not (
-            isinstance(self._domain_var, _VarData)
+            isinstance(self._domain_var, VarData)
             or isinstance(self._domain_var, IndexedVar)
         ):
             msg = (
@@ -1247,7 +1249,7 @@ def __init__(self, *args, **kwds):
             )
             raise TypeError(msg % (repr(self._domain_var),))
         if not (
-            isinstance(self._range_var, _VarData)
+            isinstance(self._range_var, VarData)
             or isinstance(self._range_var, IndexedVar)
         ):
             msg = (
@@ -1357,22 +1359,22 @@ def add(self, index, _is_indexed=None):
         _self_yvar = None
         _self_domain_pts_index = None
         if not _is_indexed:
-            # allows one to mix Var and _VarData as input to
+            # allows one to mix Var and VarData as input to
             # non-indexed Piecewise, index would be None in this case
-            # so for Var elements Var[None] is Var, but _VarData[None] would fail
+            # so for Var elements Var[None] is Var, but VarData[None] would fail
             _self_xvar = self._domain_var
             _self_yvar = self._range_var
             _self_domain_pts_index = self._domain_points[index]
         else:
-            # The following allows one to specify a Var or _VarData
+            # The following allows one to specify a Var or VarData
             # object even with an indexed Piecewise component.
             # The most common situation will most likely be a VarArray,
             # so we try this first.
-            if not isinstance(self._domain_var, _VarData):
+            if not isinstance(self._domain_var, VarData):
                 _self_xvar = self._domain_var[index]
             else:
                 _self_xvar = self._domain_var
-            if not isinstance(self._range_var, _VarData):
+            if not isinstance(self._range_var, VarData):
                 _self_yvar = self._range_var[index]
             else:
                 _self_yvar = self._range_var
@@ -1544,7 +1546,7 @@ def add(self, index, _is_indexed=None):
                     raise ValueError(msg % (self.name, index, self._pw_rep))
 
         if _is_indexed:
-            comp = _PiecewiseData(self)
+            comp = PiecewiseData(self)
         else:
             comp = self
         self._data[index] = comp
@@ -1554,9 +1556,9 @@ def add(self, index, _is_indexed=None):
         comp.build_constraints(func, _self_xvar, _self_yvar)
 
 
-class SimplePiecewise(_PiecewiseData, Piecewise):
+class SimplePiecewise(PiecewiseData, Piecewise):
     def __init__(self, *args, **kwds):
-        _PiecewiseData.__init__(self, self)
+        PiecewiseData.__init__(self, self)
         Piecewise.__init__(self, *args, **kwds)
 
 
diff --git a/pyomo/core/base/plugin.py b/pyomo/core/base/plugin.py
index 4ecb12d86a6..062e9f9fb85 100644
--- a/pyomo/core/base/plugin.py
+++ b/pyomo/core/base/plugin.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -21,30 +21,6 @@
     calling_frame=inspect.currentframe().f_back,
 )
 
-__all__ = [
-    'pyomo_callback',
-    'IPyomoExpression',
-    'ExpressionFactory',
-    'ExpressionRegistration',
-    'IPyomoPresolver',
-    'IPyomoPresolveAction',
-    'IParamRepresentation',
-    'ParamRepresentationFactory',
-    'IPyomoScriptPreprocess',
-    'IPyomoScriptCreateModel',
-    'IPyomoScriptCreateDataPortal',
-    'IPyomoScriptModifyInstance',
-    'IPyomoScriptPrintModel',
-    'IPyomoScriptPrintInstance',
-    'IPyomoScriptSaveInstance',
-    'IPyomoScriptPrintResults',
-    'IPyomoScriptSaveResults',
-    'IPyomoScriptPostprocess',
-    'ModelComponentFactory',
-    'Transformation',
-    'TransformationFactory',
-]
-
 from pyomo.core.base.component import ModelComponentFactory
 from pyomo.core.base.transformation import (
     Transformation,
diff --git a/pyomo/core/base/range.py b/pyomo/core/base/range.py
index 9df4828f550..acb004e3b10 100644
--- a/pyomo/core/base/range.py
+++ b/pyomo/core/base/range.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/base/rangeset.py b/pyomo/core/base/rangeset.py
index 18dedb84c34..32e41698aab 100644
--- a/pyomo/core/base/rangeset.py
+++ b/pyomo/core/base/rangeset.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,8 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['RangeSet']
-
 from .set import RangeSet
 
 from pyomo.common.deprecation import deprecation_warning
diff --git a/pyomo/core/base/reference.py b/pyomo/core/base/reference.py
index 79ae83b97be..558ced64f1b 100644
--- a/pyomo/core/base/reference.py
+++ b/pyomo/core/base/reference.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -18,7 +18,7 @@
     Sequence,
 )
 from pyomo.common.modeling import NOTSET
-from pyomo.core.base.set import DeclareGlobalSet, Set, SetOf, OrderedSetOf, _SetDataBase
+from pyomo.core.base.set import DeclareGlobalSet, Set, SetOf, OrderedSetOf, SetData
 from pyomo.core.base.component import Component, ComponentData
 from pyomo.core.base.global_set import UnindexedComponent_set
 from pyomo.core.base.enums import SortComponents
@@ -579,7 +579,7 @@ def Reference(reference, ctype=NOTSET):
     :py:class:`IndexedComponent`.
 
     If the indices associated with wildcards in the component slice all
-    refer to the same :py:class:`Set` objects for all data identifed by
+    refer to the same :py:class:`Set` objects for all data identified by
     the slice, then the resulting indexed component will be indexed by
     the product of those sets.  However, if all data do not share common
     set objects, or only a subset of indices in a multidimentional set
@@ -612,7 +612,7 @@ def Reference(reference, ctype=NOTSET):
         ...
         >>> m.r1 = Reference(m.b[:,:].x)
         >>> m.r1.pprint()
-        r1 : Size=4, Index=r1_index, ReferenceTo=b[:, :].x
+        r1 : Size=4, Index={1, 2}*{3, 4}, ReferenceTo=b[:, :].x
             Key    : Lower : Value : Upper : Fixed : Stale : Domain
             (1, 3) :     1 :  None :     3 : False :  True :  Reals
             (1, 4) :     1 :  None :     4 : False :  True :  Reals
@@ -625,7 +625,7 @@ def Reference(reference, ctype=NOTSET):
 
         >>> m.r2 = Reference(m.b[:,3].x)
         >>> m.r2.pprint()
-        r2 : Size=2, Index=b_index_0, ReferenceTo=b[:, 3].x
+        r2 : Size=2, Index={1, 2}, ReferenceTo=b[:, 3].x
             Key : Lower : Value : Upper : Fixed : Stale : Domain
               1 :     1 :  None :     3 : False :  True :  Reals
               2 :     2 :  None :     3 : False :  True :  Reals
@@ -642,7 +642,7 @@ def Reference(reference, ctype=NOTSET):
         ...
         >>> m.r3 = Reference(m.b[:].x[:])
         >>> m.r3.pprint()
-        r3 : Size=4, Index=r3_index, ReferenceTo=b[:].x[:]
+        r3 : Size=4, Index=ReferenceSet(b[:].x[:]), ReferenceTo=b[:].x[:]
             Key    : Lower : Value : Upper : Fixed : Stale : Domain
             (1, 3) :     1 :  None :  None : False :  True :  Reals
             (1, 4) :     1 :  None :  None : False :  True :  Reals
@@ -657,7 +657,7 @@ def Reference(reference, ctype=NOTSET):
 
         >>> m.r3[1,4] = 10
         >>> m.b[1].x.pprint()
-        x : Size=2, Index=b[1].x_index
+        x : Size=2, Index={3, 4}
             Key : Lower : Value : Upper : Fixed : Stale : Domain
               3 :     1 :  None :  None : False :  True :  Reals
               4 :     1 :    10 :  None : False : False :  Reals
@@ -774,10 +774,10 @@ def Reference(reference, ctype=NOTSET):
             # is that within the subsets list, and set is a wildcard set.
             index = wildcards[0][1]
             # index is the first wildcard set.
-            if not isinstance(index, _SetDataBase):
+            if not isinstance(index, SetData):
                 index = SetOf(index)
             for lvl, idx in wildcards[1:]:
-                if not isinstance(idx, _SetDataBase):
+                if not isinstance(idx, SetData):
                     idx = SetOf(idx)
                 index = index * idx
             # index is now either a single Set, or a SetProduct of the
diff --git a/pyomo/core/base/set.py b/pyomo/core/base/set.py
index d820ae8d933..049775fd9dd 100644
--- a/pyomo/core/base/set.py
+++ b/pyomo/core/base/set.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,6 +9,7 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
+from __future__ import annotations
 import inspect
 import itertools
 import logging
@@ -16,7 +17,10 @@
 import sys
 import weakref
 from pyomo.common.pyomo_typing import overload
+from typing import Union, Type, Any as typingAny
+from collections.abc import Iterator
 
+from pyomo.common.collections import ComponentSet
 from pyomo.common.deprecation import deprecated, deprecation_warning, RenamedClass
 from pyomo.common.errors import DeveloperError, PyomoException
 from pyomo.common.log import is_debug_set
@@ -46,7 +50,7 @@
     RangeDifferenceError,
 )
 from pyomo.core.base.component import (
-    _ComponentBase,
+    ComponentBase,
     Component,
     ComponentData,
     ModelComponentFactory,
@@ -80,10 +84,7 @@
 
 All Sets implement one of the following APIs:
 
-0. `class _SetDataBase(ComponentData)`
-   *(pure virtual interface)*
-
-1. `class _SetData(_SetDataBase)`
+1. `class SetData(ComponentData)`
    *(base class for all AML Sets)*
 
 2. `class _FiniteSetMixin(object)`
@@ -98,7 +99,7 @@
 bounded continuous ranges as well as unbounded discrete ranges).  As
 there are an infinite number of values, iteration is *not*
 supported. The base class also implements all Python set operations.
-Note that `_SetData` does *not* implement `len()`, as Python requires
+Note that `SetData` does *not* implement `len()`, as Python requires
 `len()` to return a positive integer.
 
 Finite sets add iteration and support for `len()`.  In addition, they
@@ -124,9 +125,19 @@
 
 
 def process_setarg(arg):
-    if isinstance(arg, _SetDataBase):
-        return arg
-    elif isinstance(arg, _ComponentBase):
+    if isinstance(arg, SetData):
+        if (
+            getattr(arg, '_parent', None) is not None
+            or getattr(arg, '_anonymous_sets', None) is GlobalSetBase
+            or arg.parent_component()._parent is not None
+        ):
+            return arg, None
+        _anonymous = ComponentSet((arg,))
+        if getattr(arg, '_anonymous_sets', None) is not None:
+            _anonymous.update(arg._anonymous_sets)
+        return arg, _anonymous
+
+    elif isinstance(arg, ComponentBase):
         if isinstance(arg, IndexedComponent) and arg.is_indexed():
             raise TypeError(
                 "Cannot apply a Set operator to an "
@@ -168,7 +179,7 @@ def process_setarg(arg):
             )
         ):
             ans.construct()
-        return ans
+        return process_setarg(ans)
 
     # TBD: should lists/tuples be copied into Sets, or
     # should we preserve the reference using SetOf?
@@ -188,19 +199,20 @@ def process_setarg(arg):
     # create the Set:
     #
     _defer_construct = False
-    if inspect.isgenerator(arg):
-        _ordered = True
-        _defer_construct = True
-    elif inspect.isfunction(arg):
-        _ordered = True
-        _defer_construct = True
-    elif not hasattr(arg, '__contains__'):
-        raise TypeError(
-            "Cannot create a Set from data that does not support "
-            "__contains__.  Expected set-like object supporting "
-            "collections.abc.Collection interface, but received '%s'."
-            % (type(arg).__name__,)
-        )
+    if not hasattr(arg, '__contains__'):
+        if inspect.isgenerator(arg):
+            _ordered = True
+            _defer_construct = True
+        elif inspect.isfunction(arg):
+            _ordered = True
+            _defer_construct = True
+        else:
+            raise TypeError(
+                "Cannot create a Set from data that does not support "
+                "__contains__.  Expected set-like object supporting "
+                "collections.abc.Collection interface, but received '%s'."
+                % (type(arg).__name__,)
+            )
     elif arg.__class__ is type:
         # This catches the (deprecated) RealSet API.
         return process_setarg(arg())
@@ -221,7 +233,10 @@ def process_setarg(arg):
     # Or we can do the simple thing and just use SetOf:
     #
     # ans = SetOf(arg)
-    return ans
+    _anonymous = ComponentSet((ans,))
+    if getattr(ans, '_anonymous_sets', None) is not None:
+        _anonymous.update(_anonymous_sets)
+    return ans, _anonymous
 
 
 @deprecated(
@@ -308,11 +323,22 @@ def intersect(self, other):
         else:
             self._set = SetIntersectInitializer(self._set, other)
 
-    def __call__(self, parent, idx):
+    def __call__(self, parent, idx, obj):
         if self._set is None:
             return Any
-        else:
-            return process_setarg(self._set(parent, idx))
+        _ans, _anonymous = process_setarg(self._set(parent, idx))
+        if _anonymous:
+            pc = obj.parent_component()
+            if getattr(pc, '_anonymous_sets', None) is None:
+                pc._anonymous_sets = _anonymous
+            else:
+                pc._anonymous_sets.update(_anonymous)
+            for _set in _anonymous:
+                _set._parent = pc._parent
+            if pc._constructed:
+                for _set in _anonymous:
+                    _set.construct()
+        return _ans
 
     def constant(self):
         return self._set is None or self._set.constant()
@@ -483,16 +509,8 @@ class _NotFound(object):
     pass
 
 
-# A trivial class that we can use to test if an object is a "legitimate"
-# set (either ScalarSet, or a member of an IndexedSet)
-class _SetDataBase(ComponentData):
-    """The base for all objects that can be used as a component indexing set."""
-
-    __slots__ = ()
-
-
-class _SetData(_SetDataBase):
-    """The base for all Pyomo AML objects that can be used as a component
+class SetData(ComponentData):
+    """The base for all Pyomo objects that can be used as a component
     indexing set.
 
     Derived versions of this class can be used as the Index for any
@@ -505,13 +523,13 @@ def __contains__(self, value):
             ans = self.get(value, _NotFound)
         except TypeError:
             # In Python 3.x, Sets are unhashable
-            if isinstance(value, _SetData):
+            if isinstance(value, SetData):
                 ans = _NotFound
             else:
                 raise
 
         if ans is _NotFound:
-            if isinstance(value, _SetData):
+            if isinstance(value, SetData):
                 deprecation_warning(
                     "Testing for set subsets with 'a in b' is deprecated.  "
                     "Use 'a.issubset(b)'.",
@@ -543,7 +561,7 @@ def isordered(self):
     def subsets(self, expand_all_set_operators=None):
         return iter((self,))
 
-    def __iter__(self):
+    def __iter__(self) -> Iterator[typingAny]:
         """Iterate over the set members
 
         Raises AttributeError for non-finite sets.  This must be
@@ -563,6 +581,8 @@ def __eq__(self, other):
         # ranges (or no ranges).  We will re-generate non-finite sets to
         # make sure we get an accurate "finiteness" flag.
         if hasattr(other, 'isfinite'):
+            if not other.parent_component().is_constructed():
+                return False
             other_isfinite = other.isfinite()
             if not other_isfinite:
                 try:
@@ -863,7 +883,7 @@ def _get_continuous_interval(self):
     @property
     @deprecated("The 'virtual' attribute is no longer supported", version='5.7')
     def virtual(self):
-        return isinstance(self, (_AnySet, SetOperator, _InfiniteRangeSetData))
+        return isinstance(self, (_AnySet, SetOperator, InfiniteRangeSetData))
 
     @virtual.setter
     def virtual(self, value):
@@ -1126,33 +1146,23 @@ def cross(self, *args):
 
     def __ror__(self, other):
         # See the discussion of Set vs SetOf in process_setarg above
-        #
-        # return SetOf(other) | self
-        return process_setarg(other) | self
+        return SetUnion(other, self)
 
     def __rand__(self, other):
         # See the discussion of Set vs SetOf in process_setarg above
-        #
-        # return SetOf(other) & self
-        return process_setarg(other) & self
+        return SetIntersection(other, self)
 
     def __rsub__(self, other):
         # See the discussion of Set vs SetOf in process_setarg above
-        #
-        # return SetOf(other) - self
-        return process_setarg(other) - self
+        return SetDifference(other, self)
 
     def __rxor__(self, other):
         # See the discussion of Set vs SetOf in process_setarg above
-        #
-        # return SetOf(other) ^ self
-        return process_setarg(other) ^ self
+        return SetSymmetricDifference(other, self)
 
     def __rmul__(self, other):
         # See the discussion of Set vs SetOf in process_setarg above
-        #
-        # return SetOf(other) * self
-        return process_setarg(other) * self
+        return SetProduct(other, self)
 
     def __lt__(self, other):
         """
@@ -1167,6 +1177,16 @@ def __gt__(self, other):
         return self >= other and not self == other
 
 
+class _SetData(metaclass=RenamedClass):
+    __renamed__new_class__ = SetData
+    __renamed__version__ = '6.7.2'
+
+
+class _SetDataBase(metaclass=RenamedClass):
+    __renamed__new_class__ = SetData
+    __renamed__version__ = '6.7.2'
+
+
 class _FiniteSetMixin(object):
     __slots__ = ()
 
@@ -1273,14 +1293,14 @@ def ranges(self):
                     yield NonNumericRange(i)
 
 
-class _FiniteSetData(_FiniteSetMixin, _SetData):
+class FiniteSetData(_FiniteSetMixin, SetData):
     """A general unordered iterable Set"""
 
     __slots__ = ('_values', '_domain', '_validate', '_filter', '_dimen')
 
     def __init__(self, component):
-        _SetData.__init__(self, component=component)
-        # Derived classes (like _OrderedSetData) may want to change the
+        SetData.__init__(self, component=component)
+        # Derived classes (like OrderedSetData) may want to change the
         # storage
         if not hasattr(self, '_values'):
             self._values = set()
@@ -1318,7 +1338,7 @@ def __len__(self):
         return len(self._values)
 
     def __str__(self):
-        if self.parent_block() is not None:
+        if self.parent_component()._name is not None:
             return self.name
         if not self.parent_component()._constructed:
             return type(self).__name__
@@ -1356,8 +1376,10 @@ def add(self, *values):
             else:
                 # If we are not normalizing indices, then we cannot reliably
                 # infer the set dimen
+                _d = 1
+                if isinstance(value, Sequence) and self.dimen != 1:
+                    _d = len(value)
                 _value = value
-                _d = None
             if _value not in self._domain:
                 raise ValueError(
                     "Cannot add value %s to Set %s.\n"
@@ -1447,6 +1469,11 @@ def pop(self):
         return self._values.pop()
 
 
+class _FiniteSetData(metaclass=RenamedClass):
+    __renamed__new_class__ = FiniteSetData
+    __renamed__version__ = '6.7.2'
+
+
 class _ScalarOrderedSetMixin(object):
     # This mixin is required because scalar ordered sets implement
     # __getitem__() as an alias of at()
@@ -1607,16 +1634,16 @@ def _to_0_based_index(self, item):
             )
 
 
-class _OrderedSetData(_OrderedSetMixin, _FiniteSetData):
+class OrderedSetData(_OrderedSetMixin, FiniteSetData):
     """
     This class defines the base class for an ordered set of concrete data.
 
     In older Pyomo terms, this defines a "concrete" ordered set - that is,
     a set that "owns" the list of set members.  While this class actually
     implements a set ordered by insertion order, we make the "official"
-    _InsertionOrderSetData an empty derivative class, so that
+    InsertionOrderSetData an empty derivative class, so that
 
-         issubclass(_SortedSetData, _InsertionOrderSetData) == False
+         issubclass(SortedSetData, InsertionOrderSetData) == False
 
     Constructor Arguments:
         component   The Set object that owns this data.
@@ -1629,7 +1656,7 @@ class _OrderedSetData(_OrderedSetMixin, _FiniteSetData):
     def __init__(self, component):
         self._values = {}
         self._ordered_values = []
-        _FiniteSetData.__init__(self, component=component)
+        FiniteSetData.__init__(self, component=component)
 
     def _iter_impl(self):
         """
@@ -1707,7 +1734,12 @@ def ord(self, item):
             raise ValueError("%s.ord(x): x not in %s" % (self.name, self.name))
 
 
-class _InsertionOrderSetData(_OrderedSetData):
+class _OrderedSetData(metaclass=RenamedClass):
+    __renamed__new_class__ = OrderedSetData
+    __renamed__version__ = '6.7.2'
+
+
+class InsertionOrderSetData(OrderedSetData):
     """
     This class defines the data for a ordered set where the items are ordered
     in insertion order (similar to Python's OrderedSet.
@@ -1728,7 +1760,7 @@ def set_value(self, val):
                 "This WILL potentially lead to nondeterministic behavior "
                 "in Pyomo" % (type(val).__name__,)
             )
-        super(_InsertionOrderSetData, self).set_value(val)
+        super(InsertionOrderSetData, self).set_value(val)
 
     def update(self, values):
         if type(values) in Set._UnorderedInitializers:
@@ -1738,7 +1770,12 @@ def update(self, values):
                 "This WILL potentially lead to nondeterministic behavior "
                 "in Pyomo" % (type(values).__name__,)
             )
-        super(_InsertionOrderSetData, self).update(values)
+        super(InsertionOrderSetData, self).update(values)
+
+
+class _InsertionOrderSetData(metaclass=RenamedClass):
+    __renamed__new_class__ = InsertionOrderSetData
+    __renamed__version__ = '6.7.2'
 
 
 class _SortedSetMixin(object):
@@ -1753,7 +1790,7 @@ def sorted_iter(self):
         return iter(self)
 
 
-class _SortedSetData(_SortedSetMixin, _OrderedSetData):
+class SortedSetData(_SortedSetMixin, OrderedSetData):
     """
     This class defines the data for a sorted set.
 
@@ -1768,7 +1805,7 @@ class _SortedSetData(_SortedSetMixin, _OrderedSetData):
     def __init__(self, component):
         # An empty set is sorted...
         self._is_sorted = True
-        _OrderedSetData.__init__(self, component=component)
+        OrderedSetData.__init__(self, component=component)
 
     def _iter_impl(self):
         """
@@ -1776,12 +1813,12 @@ def _iter_impl(self):
         """
         if not self._is_sorted:
             self._sort()
-        return super(_SortedSetData, self)._iter_impl()
+        return super(SortedSetData, self)._iter_impl()
 
     def __reversed__(self):
         if not self._is_sorted:
             self._sort()
-        return super(_SortedSetData, self).__reversed__()
+        return super(SortedSetData, self).__reversed__()
 
     def _add_impl(self, value):
         # Note that the sorted status has no bearing on insertion,
@@ -1795,7 +1832,7 @@ def _add_impl(self, value):
     # def discard(self, val):
 
     def clear(self):
-        super(_SortedSetData, self).clear()
+        super(SortedSetData, self).clear()
         self._is_sorted = True
 
     def at(self, index):
@@ -1807,7 +1844,7 @@ def at(self, index):
         """
         if not self._is_sorted:
             self._sort()
-        return super(_SortedSetData, self).at(index)
+        return super(SortedSetData, self).at(index)
 
     def ord(self, item):
         """
@@ -1819,7 +1856,7 @@ def ord(self, item):
         """
         if not self._is_sorted:
             self._sort()
-        return super(_SortedSetData, self).ord(item)
+        return super(SortedSetData, self).ord(item)
 
     def sorted_data(self):
         return self.data()
@@ -1832,6 +1869,11 @@ def _sort(self):
         self._is_sorted = True
 
 
+class _SortedSetData(metaclass=RenamedClass):
+    __renamed__new_class__ = SortedSetData
+    __renamed__version__ = '6.7.2'
+
+
 ############################################################################
 
 _SET_API = (('__contains__', 'test membership in'), 'get', 'ranges', 'bounds')
@@ -1890,7 +1932,8 @@ class Set(IndexedComponent):
 
     within : initialiser(set), optional
         A set that defines the valid values that can be contained
-        in this set
+        in this set. If the latter is indexed, the former can be indexed or
+        non-indexed, in which case it applies to all indices.
     domain : initializer(set), optional
         A set that defines the valid values that can be contained
         in this set
@@ -1944,9 +1987,15 @@ class InsertionOrder(object):
     class SortedOrder(object):
         pass
 
-    _ValidOrderedAuguments = {True, False, InsertionOrder, SortedOrder}
+    _ValidOrderedArguments = {True, False, InsertionOrder, SortedOrder}
     _UnorderedInitializers = {set}
 
+    @overload
+    def __new__(cls: Type[Set], *args, **kwds) -> Union[SetData, IndexedSet]: ...
+
+    @overload
+    def __new__(cls: Type[OrderedScalarSet], *args, **kwds) -> OrderedScalarSet: ...
+
     def __new__(cls, *args, **kwds):
         if cls is not Set:
             return super(Set, cls).__new__(cls)
@@ -1956,7 +2005,7 @@ def __new__(cls, *args, **kwds):
         # Many things are easier by forcing it to be consistent across
         # the set (namely, the _ComponentDataClass is constant).
         # However, it is a bit off that 'ordered' it the only arg NOT
-        # processed by Initializer.  We can mock up a _SortedSetData
+        # processed by Initializer.  We can mock up a SortedSetData
         # sort function that preserves Insertion Order (lambda x: x), but
         # the unsorted is harder (it would effectively be insertion
         # order, but ordered() may not be deterministic based on how the
@@ -1967,7 +2016,7 @@ def __new__(cls, *args, **kwds):
         ordered = kwds.get('ordered', Set.InsertionOrder)
         if ordered is True:
             ordered = Set.InsertionOrder
-        if ordered not in Set._ValidOrderedAuguments:
+        if ordered not in Set._ValidOrderedArguments:
             if inspect.isfunction(ordered):
                 ordered = Set.SortedOrder
             else:
@@ -1984,7 +2033,7 @@ def __new__(cls, *args, **kwds):
                             str(_)
                             for _ in sorted_robust(
                                 'Set.' + x.__name__ if isinstance(x, type) else x
-                                for x in Set._ValidOrderedAuguments.union(
+                                for x in Set._ValidOrderedArguments.union(
                                     {'<function>'}
                                 )
                             )
@@ -2001,11 +2050,11 @@ def __new__(cls, *args, **kwds):
         else:
             newObj = super(Set, cls).__new__(IndexedSet)
             if ordered is Set.InsertionOrder:
-                newObj._ComponentDataClass = _InsertionOrderSetData
+                newObj._ComponentDataClass = InsertionOrderSetData
             elif ordered is Set.SortedOrder:
-                newObj._ComponentDataClass = _SortedSetData
+                newObj._ComponentDataClass = SortedSetData
             else:
-                newObj._ComponentDataClass = _FiniteSetData
+                newObj._ComponentDataClass = FiniteSetData
             return newObj
 
     @overload
@@ -2088,7 +2137,7 @@ def __init__(self, *args, **kwds):
         # order to correctly parse the data stream.
         if not self.is_indexed():
             if self._init_domain.constant():
-                self._domain = self._init_domain(self.parent_block(), None)
+                self._domain = self._init_domain(self.parent_block(), None, self)
             if self._init_dimen.constant():
                 self._dimen = self._init_dimen(self.parent_block(), None)
 
@@ -2104,10 +2153,16 @@ def check_values(self):
     def construct(self, data=None):
         if self._constructed:
             return
+        self._constructed = True
+
         timer = ConstructionTimer(self)
         if is_debug_set(logger):
-            logger.debug("Constructing Set, name=%s, from data=%r" % (self.name, data))
-        self._constructed = True
+            logger.debug("Constructing Set, name=%s, from data=%r" % (self, data))
+
+        if self._anonymous_sets is not None:
+            for _set in self._anonymous_sets:
+                _set.construct()
+
         if data is not None:
             # Data supplied to construct() should override data provided
             # to the constructor
@@ -2143,7 +2198,7 @@ def _getitem_when_not_present(self, index):
         """Returns the default component data value."""
         # Because we allow sets within an IndexedSet to have different
         # dimen, we have moved the tuplization logic from PyomoModel
-        # into Set (because we cannot know the dimen of a _SetData until
+        # into Set (because we cannot know the dimen of a SetData until
         # we are actually constructing that index).  This also means
         # that we need to potentially communicate the dimen to the
         # (wrapped) value initializer.  So, we will get the dimen first,
@@ -2162,7 +2217,9 @@ def _getitem_when_not_present(self, index):
             )
             _d = None
 
-        domain = self._init_domain(_block, index)
+        domain = self._init_domain(_block, index, self)
+        if domain is not None:
+            domain.parent_component().construct()
         if _d is UnknownSetDimen and domain is not None and domain.dimen is not None:
             _d = domain.dimen
 
@@ -2186,11 +2243,9 @@ def _getitem_when_not_present(self, index):
         else:
             obj = self._data[index] = self._ComponentDataClass(component=self)
         obj._index = index
+        obj._domain = domain
         if _d is not UnknownSetDimen:
             obj._dimen = _d
-        if domain is not None:
-            obj._domain = domain
-            domain.parent_component().construct()
         if self._init_validate is not None:
             try:
                 obj._validate = Initializer(self._init_validate(_block, index))
@@ -2303,7 +2358,7 @@ def _pprint(self):
         #         else:
         #             return '{' + str(ans)[1:-1] + "}"
 
-        # TBD: In the current design, we force all _SetData within an
+        # TBD: In the current design, we force all SetData within an
         # indexed Set to have the same isordered value, so we will only
         # print it once in the header.  Is this a good design?
         try:
@@ -2323,7 +2378,7 @@ def _pprint(self):
                     _ordered = "Sorted"
                 else:
                     _ordered = "{user}"
-            elif issubclass(_refClass, _InsertionOrderSetData):
+            elif issubclass(_refClass, InsertionOrderSetData):
                 _ordered = "Insertion"
         return (
             [
@@ -2347,10 +2402,15 @@ def data(self):
         "Return a dict containing the data() of each Set in this IndexedSet"
         return {k: v.data() for k, v in self.items()}
 
+    @overload
+    def __getitem__(self, index) -> SetData: ...
+
+    __getitem__ = IndexedComponent.__getitem__  # type: ignore
+
 
-class FiniteScalarSet(_FiniteSetData, Set):
+class FiniteScalarSet(FiniteSetData, Set):
     def __init__(self, **kwds):
-        _FiniteSetData.__init__(self, component=self)
+        FiniteSetData.__init__(self, component=self)
         Set.__init__(self, **kwds)
         self._index = UnindexedComponent_index
 
@@ -2360,13 +2420,13 @@ class FiniteSimpleSet(metaclass=RenamedClass):
     __renamed__version__ = '6.0'
 
 
-class OrderedScalarSet(_ScalarOrderedSetMixin, _InsertionOrderSetData, Set):
+class OrderedScalarSet(_ScalarOrderedSetMixin, InsertionOrderSetData, Set):
     def __init__(self, **kwds):
         # In case someone inherits from us, we will provide a rational
         # default for the "ordered" flag
         kwds.setdefault('ordered', Set.InsertionOrder)
 
-        _InsertionOrderSetData.__init__(self, component=self)
+        InsertionOrderSetData.__init__(self, component=self)
         Set.__init__(self, **kwds)
 
 
@@ -2375,13 +2435,13 @@ class OrderedSimpleSet(metaclass=RenamedClass):
     __renamed__version__ = '6.0'
 
 
-class SortedScalarSet(_ScalarOrderedSetMixin, _SortedSetData, Set):
+class SortedScalarSet(_ScalarOrderedSetMixin, SortedSetData, Set):
     def __init__(self, **kwds):
         # In case someone inherits from us, we will provide a rational
         # default for the "ordered" flag
         kwds.setdefault('ordered', Set.SortedOrder)
 
-        _SortedSetData.__init__(self, component=self)
+        SortedSetData.__init__(self, component=self)
         Set.__init__(self, **kwds)
         self._index = UnindexedComponent_index
 
@@ -2424,14 +2484,14 @@ class AbstractSortedSimpleSet(metaclass=RenamedClass):
 ############################################################################
 
 
-class SetOf(_SetData, Component):
+class SetOf(SetData, Component):
     """"""
 
     def __new__(cls, *args, **kwds):
         if cls is not SetOf:
             return super(SetOf, cls).__new__(cls)
         (reference,) = args
-        if isinstance(reference, (_SetData, GlobalSetBase)):
+        if isinstance(reference, (SetData, GlobalSetBase)):
             if reference.isfinite():
                 if reference.isordered():
                     return super(SetOf, cls).__new__(OrderedSetOf)
@@ -2445,30 +2505,30 @@ def __new__(cls, *args, **kwds):
             return super(SetOf, cls).__new__(FiniteSetOf)
 
     def __init__(self, reference, **kwds):
-        _SetData.__init__(self, component=self)
+        SetData.__init__(self, component=self)
         kwds.setdefault('ctype', SetOf)
         Component.__init__(self, **kwds)
         self._ref = reference
+        self.construct()
 
     def __str__(self):
-        if self.parent_block() is not None:
+        if self._name is not None:
             return self.name
         return str(self._ref)
 
     def construct(self, data=None):
         if self._constructed:
             return
+        self._constructed = True
+
         timer = ConstructionTimer(self)
         if is_debug_set(logger):
-            logger.debug(
-                "Constructing SetOf, name=%s, from data=%r" % (self.name, data)
-            )
-        self._constructed = True
+            logger.debug("Constructing SetOf, name=%s, from data=%r" % (self, data))
         timer.report()
 
     @property
     def dimen(self):
-        if isinstance(self._ref, _SetData):
+        if isinstance(self._ref, SetData):
             return self._ref.dimen
         _iter = iter(self)
         try:
@@ -2563,7 +2623,7 @@ def ord(self, item):
 ############################################################################
 
 
-class _InfiniteRangeSetData(_SetData):
+class InfiniteRangeSetData(SetData):
     """Data class for a infinite set.
 
     This Set implements an interface to an *infinite set* defined by one
@@ -2575,7 +2635,7 @@ class _InfiniteRangeSetData(_SetData):
     __slots__ = ('_ranges',)
 
     def __init__(self, component):
-        _SetData.__init__(self, component=component)
+        SetData.__init__(self, component=component)
         self._ranges = None
 
     def get(self, value, default=None):
@@ -2608,8 +2668,13 @@ def ranges(self):
         return iter(self._ranges)
 
 
-class _FiniteRangeSetData(
-    _SortedSetMixin, _OrderedSetMixin, _FiniteSetMixin, _InfiniteRangeSetData
+class _InfiniteRangeSetData(metaclass=RenamedClass):
+    __renamed__new_class__ = InfiniteRangeSetData
+    __renamed__version__ = '6.7.2'
+
+
+class FiniteRangeSetData(
+    _SortedSetMixin, _OrderedSetMixin, _FiniteSetMixin, InfiniteRangeSetData
 ):
     __slots__ = ()
 
@@ -2632,7 +2697,7 @@ def _iter_impl(self):
         # iterate over it
         nIters = len(self._ranges) - 1
         if not nIters:
-            yield from _FiniteRangeSetData._range_gen(self._ranges[0])
+            yield from FiniteRangeSetData._range_gen(self._ranges[0])
             return
 
         # The trick here is that we need to remove any duplicates from
@@ -2643,7 +2708,7 @@ def _iter_impl(self):
         for r in self._ranges:
             # Note: there should always be at least 1 member in each
             # NumericRange
-            i = _FiniteRangeSetData._range_gen(r)
+            i = FiniteRangeSetData._range_gen(r)
             iters.append([next(i), i])
 
         iters.sort(reverse=True, key=lambda x: x[0])
@@ -2709,11 +2774,16 @@ def ord(self, item):
         )
 
     # We must redefine ranges(), bounds(), and domain so that we get the
-    # _InfiniteRangeSetData version and not the one from
+    # InfiniteRangeSetData version and not the one from
     # _FiniteSetMixin.
-    bounds = _InfiniteRangeSetData.bounds
-    ranges = _InfiniteRangeSetData.ranges
-    domain = _InfiniteRangeSetData.domain
+    bounds = InfiniteRangeSetData.bounds
+    ranges = InfiniteRangeSetData.ranges
+    domain = InfiniteRangeSetData.domain
+
+
+class _FiniteRangeSetData(metaclass=RenamedClass):
+    __renamed__new_class__ = FiniteRangeSetData
+    __renamed__version__ = '6.7.2'
 
 
 @ModelComponentFactory.register(
@@ -2932,14 +3002,12 @@ def __init__(self, *args, **kwds):
             pass
 
     def __str__(self):
-        if self.parent_block() is not None:
+        # Named components should return their name e.g., Reals
+        if self._name is not None:
             return self.name
         # Unconstructed floating components return their type
         if not self._constructed:
             return type(self).__name__
-        # Named, constructed components should return their name e.g., Reals
-        if type(self).__name__ != self._name:
-            return self.name
         # Floating, unnamed constructed components return their ranges()
         ans = ' | '.join(str(_) for _ in self.ranges())
         if ' | ' in ans:
@@ -2952,11 +3020,16 @@ def __str__(self):
     def construct(self, data=None):
         if self._constructed:
             return
+
         timer = ConstructionTimer(self)
         if is_debug_set(logger):
-            logger.debug(
-                "Constructing RangeSet, name=%s, from data=%r" % (self.name, data)
-            )
+            logger.debug("Constructing RangeSet, name=%s, from data=%r" % (self, data))
+        # Note: we cannot set the constructed flag until after we have
+        # generated the debug message: the debug message needs the name,
+        # which in turn may need ranges(), which has not been
+        # constructed.
+        self._constructed = True
+
         if data is not None:
             raise ValueError(
                 "RangeSet.construct() does not support the data= argument.\n"
@@ -2964,19 +3037,9 @@ def construct(self, data=None):
                 "as numbers, constants, or Params to the RangeSet() "
                 "declaration"
             )
-        self._constructed = True
 
         args, ranges = self._init_data
-        if any(not is_constant(arg) for arg in args):
-            logger.warning(
-                "Constructing RangeSet '%s' from non-constant data (e.g., "
-                "Var or mutable Param).  The linkage between this RangeSet "
-                "and the original source data will be broken, so updating "
-                "the data value in the future will not be reflected in this "
-                "RangeSet.  To suppress this warning, explicitly convert "
-                "the source data to a constant type (e.g., float, int, or "
-                "immutable Param)" % (self.name,)
-            )
+        nonconstant_data_warning = any(not is_constant(arg) for arg in args)
         args = tuple(value(arg) for arg in args)
         if type(ranges) is not tuple:
             ranges = tuple(ranges)
@@ -3087,7 +3150,7 @@ def construct(self, data=None):
             old_ranges.reverse()
             while old_ranges:
                 r = old_ranges.pop()
-                for i, val in enumerate(_FiniteRangeSetData._range_gen(r)):
+                for i, val in enumerate(FiniteRangeSetData._range_gen(r)):
                     if not _filter(_block, val):
                         split_r = r.range_difference((NumericRange(val, val, 0),))
                         if len(split_r) == 2:
@@ -3137,6 +3200,22 @@ def construct(self, data=None):
                         "Set %s" % (val, self.name)
                     )
 
+        # Defer the warning about non-constant args until after the
+        # component has been constructed, so that the conversion of the
+        # component to a rational string will work (anonymous RangeSets
+        # will report their ranges, which aren't present until
+        # construction is over)
+        if nonconstant_data_warning:
+            logger.warning(
+                "Constructing RangeSet '%s' from non-constant data (e.g., "
+                "Var or mutable Param).  The linkage between this RangeSet "
+                "and the original source data will be broken, so updating "
+                "the data value in the future will not be reflected in this "
+                "RangeSet.  To suppress this warning, explicitly convert "
+                "the source data to a constant type (e.g., float, int, or "
+                "immutable Param)" % (self,)
+            )
+
         timer.report()
 
     #
@@ -3169,9 +3248,9 @@ def _pprint(self):
         )
 
 
-class InfiniteScalarRangeSet(_InfiniteRangeSetData, RangeSet):
+class InfiniteScalarRangeSet(InfiniteRangeSetData, RangeSet):
     def __init__(self, *args, **kwds):
-        _InfiniteRangeSetData.__init__(self, component=self)
+        InfiniteRangeSetData.__init__(self, component=self)
         RangeSet.__init__(self, *args, **kwds)
         self._index = UnindexedComponent_index
 
@@ -3184,9 +3263,9 @@ class InfiniteSimpleRangeSet(metaclass=RenamedClass):
     __renamed__version__ = '6.0'
 
 
-class FiniteScalarRangeSet(_ScalarOrderedSetMixin, _FiniteRangeSetData, RangeSet):
+class FiniteScalarRangeSet(_ScalarOrderedSetMixin, FiniteRangeSetData, RangeSet):
     def __init__(self, *args, **kwds):
-        _FiniteRangeSetData.__init__(self, component=self)
+        FiniteRangeSetData.__init__(self, component=self)
         RangeSet.__init__(self, *args, **kwds)
         self._index = UnindexedComponent_index
 
@@ -3224,37 +3303,43 @@ class AbstractFiniteSimpleRangeSet(metaclass=RenamedClass):
 ############################################################################
 
 
-class SetOperator(_SetData, Set):
+class SetOperator(SetData, Set):
     __slots__ = ('_sets',)
 
     def __init__(self, *args, **kwds):
-        _SetData.__init__(self, component=self)
+        SetData.__init__(self, component=self)
         Set.__init__(self, **kwds)
-        implicit = []
-        sets = []
-        for _set in args:
-            _new_set = process_setarg(_set)
-            sets.append(_new_set)
-            if _new_set is not _set or _new_set.parent_block() is None:
-                implicit.append(_new_set)
-        self._sets = tuple(sets)
-        self._implicit_subsets = tuple(implicit)
-        # We will implicitly construct all set operators if the operands
-        # are all constructed.
+        self._sets, _anonymous = zip(*(process_setarg(_set) for _set in args))
+        _anonymous = tuple(filter(None, _anonymous))
+        if _anonymous:
+            self._anonymous_sets = ComponentSet()
+            for _set in _anonymous:
+                self._anonymous_sets.update(_set)
+        # We will immediately construct all set operators if the operands
+        # are all themselves constructed.
         if all(_.parent_component()._constructed for _ in self._sets):
             self.construct()
 
     def construct(self, data=None):
         if self._constructed:
             return
+        self._constructed = True
+
         timer = ConstructionTimer(self)
         if is_debug_set(logger):
             logger.debug(
-                "Constructing SetOperator, name=%s, from data=%r" % (self.name, data)
+                "Constructing SetOperator, name=%s, from data=%r" % (self, data)
             )
-        for s in self._sets:
-            s.parent_component().construct()
-        super(SetOperator, self).construct()
+
+        if self._anonymous_sets is not None:
+            for _set in self._anonymous_sets:
+                _set.construct()
+
+        # This ensures backwards compatibility by causing all scalar
+        # sets (including set operators) to be initialized (and
+        # potentially empty) after construct().
+        self._getitem_when_not_present(None)
+
         if data:
             deprecation_warning(
                 "Providing construction data to SetOperator objects is "
@@ -3275,7 +3360,7 @@ def construct(self, data=None):
             if fail:
                 raise ValueError(
                     "Constructing SetOperator %s with incompatible data "
-                    "(data=%s}" % (self.name, data)
+                    "(data=%s}" % (self, data)
                 )
         timer.report()
 
@@ -3301,7 +3386,7 @@ def __len__(self):
         )
 
     def __str__(self):
-        if self.parent_block() is not None:
+        if self._name is not None:
             return self.name
         return self._expression_str()
 
@@ -3406,7 +3491,7 @@ def _domain(self, val):
     def _checkArgs(*sets):
         ans = []
         for s in sets:
-            if isinstance(s, _SetDataBase):
+            if isinstance(s, SetData):
                 ans.append((s.isordered(), s.isfinite()))
             elif type(s) in {tuple, list}:
                 ans.append((True, True))
@@ -3895,7 +3980,7 @@ def bounds(self):
     @property
     def dimen(self):
         if not (FLATTEN_CROSS_PRODUCT and normalize_index.flatten):
-            return None
+            return len(self._sets)
         # By convention, "None" trumps UnknownSetDimen.  That is, a set
         # product is "non-dimentioned" if any term is non-dimentioned,
         # even if we do not yet know the dimentionality of another term.
@@ -4162,9 +4247,9 @@ def ord(self, item):
 ############################################################################
 
 
-class _AnySet(_SetData, Set):
+class _AnySet(SetData, Set):
     def __init__(self, **kwds):
-        _SetData.__init__(self, component=self)
+        SetData.__init__(self, component=self)
         # There is a chicken-and-egg game here: the SetInitializer uses
         # Any as part of the processing of the domain/within/bounds
         # domain restrictions.  However, Any has not been declared when
@@ -4173,6 +4258,7 @@ def __init__(self, **kwds):
         # accept (and ignore) this value.
         kwds.setdefault('domain', self)
         Set.__init__(self, **kwds)
+        self.construct()
 
     def get(self, val, default=None):
         return val if val is not Ellipsis else default
@@ -4200,7 +4286,7 @@ def domain(self):
         return Any
 
     def __str__(self):
-        if self.parent_block() is not None:
+        if self._name is not None:
             return self.name
         return type(self).__name__
 
@@ -4217,10 +4303,11 @@ def get(self, val, default=None):
         return super(_AnyWithNoneSet, self).get(val, default)
 
 
-class _EmptySet(_FiniteSetMixin, _SetData, Set):
+class _EmptySet(_FiniteSetMixin, SetData, Set):
     def __init__(self, **kwds):
-        _SetData.__init__(self, component=self)
+        SetData.__init__(self, component=self)
         Set.__init__(self, **kwds)
+        self.construct()
 
     def get(self, val, default=None):
         return default
@@ -4245,7 +4332,7 @@ def domain(self):
         return EmptySet
 
     def __str__(self):
-        if self.parent_block() is not None:
+        if self._name is not None:
             return self.name
         return type(self).__name__
 
@@ -4348,7 +4435,11 @@ def __new__(cls, *args, **kwds):
                         name = base_set.name
                     else:
                         name = cls_name
-                ans = RangeSet(ranges=list(range_init(None, None).ranges()), name=name)
+                tmp = Set()
+                ans = RangeSet(
+                    ranges=list(range_init(None, None, tmp).ranges()), name=name
+                )
+                ans._anonymous_sets = tmp._anonymous_sets
                 if name_kwd is None and (cls_name is not None or bounds is not None):
                     ans._name += str(ans.bounds())
             else:
@@ -4378,6 +4469,9 @@ def get_interval(self):
     # Cache the set bounds / interval
     _set._bounds = obj.bounds()
     _set._interval = obj.get_interval()
+    # Now that the set is constructed, override the _anonymous_sets to
+    # mark the set as a global set (used by process_setarg)
+    _set._anonymous_sets = GlobalSetBase
     return _set
 
 
diff --git a/pyomo/core/base/set_types.py b/pyomo/core/base/set_types.py
index db9fe0f796c..80c8a41ff2e 100644
--- a/pyomo/core/base/set_types.py
+++ b/pyomo/core/base/set_types.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/base/sets.py b/pyomo/core/base/sets.py
index cbaad33c0b8..72d49479dd3 100644
--- a/pyomo/core/base/sets.py
+++ b/pyomo/core/base/sets.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -13,14 +13,12 @@
 # . rename 'filter' to something else
 # . confirm that filtering is efficient
 
-__all__ = ['Set', 'set_options', 'simple_set_rule', 'SetOf']
-
 from .set import (
     process_setarg,
     set_options,
     simple_set_rule,
     _SetDataBase,
-    _SetData,
+    SetData,
     Set,
     SetOf,
     IndexedSet,
diff --git a/pyomo/core/base/sos.py b/pyomo/core/base/sos.py
index 98cc9d28c8f..afd52c111bc 100644
--- a/pyomo/core/base/sos.py
+++ b/pyomo/core/base/sos.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,8 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['SOSConstraint']
-
 import sys
 import logging
 
@@ -30,7 +28,7 @@
 logger = logging.getLogger('pyomo.core')
 
 
-class _SOSConstraintData(ActiveComponentData):
+class SOSConstraintData(ActiveComponentData):
     """
     This class defines the data for a single special ordered set.
 
@@ -103,6 +101,11 @@ def set_items(self, variables, weights):
             self._weights.append(w)
 
 
+class _SOSConstraintData(metaclass=RenamedClass):
+    __renamed__new_class__ = SOSConstraintData
+    __renamed__version__ = '6.7.2'
+
+
 @ModelComponentFactory.register("SOS constraint expressions.")
 class SOSConstraint(ActiveIndexedComponent):
     """
@@ -514,10 +517,10 @@ def add(self, index, variables, weights=None):
         Add a component data for the specified index.
         """
         if index is None:
-            # because ScalarSOSConstraint already makes an _SOSConstraintData instance
+            # because ScalarSOSConstraint already makes an SOSConstraintData instance
             soscondata = self
         else:
-            soscondata = _SOSConstraintData(self)
+            soscondata = SOSConstraintData(self)
         self._data[index] = soscondata
         soscondata._index = index
 
@@ -551,9 +554,9 @@ def pprint(self, ostream=None, verbose=False, prefix=""):
                 ostream.write("\t\t" + str(weight) + ' : ' + var.name + '\n')
 
 
-class ScalarSOSConstraint(SOSConstraint, _SOSConstraintData):
+class ScalarSOSConstraint(SOSConstraint, SOSConstraintData):
     def __init__(self, *args, **kwd):
-        _SOSConstraintData.__init__(self, self)
+        SOSConstraintData.__init__(self, self)
         SOSConstraint.__init__(self, *args, **kwd)
         self._index = UnindexedComponent_index
 
diff --git a/pyomo/core/base/suffix.py b/pyomo/core/base/suffix.py
index 160ae20f116..be2f732650d 100644
--- a/pyomo/core/base/suffix.py
+++ b/pyomo/core/base/suffix.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,8 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ('Suffix', 'active_export_suffix_generator', 'active_import_suffix_generator')
-
 import enum
 import logging
 
@@ -343,7 +341,7 @@ def clear_all_values(self):
 
     @deprecated(
         'Suffix.set_datatype is replaced with the Suffix.datatype property',
-        version='6.7.1.dev0',
+        version='6.7.1',
     )
     def set_datatype(self, datatype):
         """
@@ -353,7 +351,7 @@ def set_datatype(self, datatype):
 
     @deprecated(
         'Suffix.get_datatype is replaced with the Suffix.datatype property',
-        version='6.7.1.dev0',
+        version='6.7.1',
     )
     def get_datatype(self):
         """
@@ -363,7 +361,7 @@ def get_datatype(self):
 
     @deprecated(
         'Suffix.set_direction is replaced with the Suffix.direction property',
-        version='6.7.1.dev0',
+        version='6.7.1',
     )
     def set_direction(self, direction):
         """
@@ -373,7 +371,7 @@ def set_direction(self, direction):
 
     @deprecated(
         'Suffix.get_direction is replaced with the Suffix.direction property',
-        version='6.7.1.dev0',
+        version='6.7.1',
     )
     def get_direction(self):
         """
diff --git a/pyomo/core/base/symbol_map.py b/pyomo/core/base/symbol_map.py
index e4e7f9d781c..189cce7646a 100644
--- a/pyomo/core/base/symbol_map.py
+++ b/pyomo/core/base/symbol_map.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/base/symbolic.py b/pyomo/core/base/symbolic.py
index 3fa5c168207..c1ee08dd584 100644
--- a/pyomo/core/base/symbolic.py
+++ b/pyomo/core/base/symbolic.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/base/template_expr.py b/pyomo/core/base/template_expr.py
index f8ff345a1e5..c3697be7eb0 100644
--- a/pyomo/core/base/template_expr.py
+++ b/pyomo/core/base/template_expr.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/base/transformation.py b/pyomo/core/base/transformation.py
index 70d89af3798..31f5a251553 100644
--- a/pyomo/core/base/transformation.py
+++ b/pyomo/core/base/transformation.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/base/units_container.py b/pyomo/core/base/units_container.py
index dd6bb75aec9..f3dec1e0db1 100644
--- a/pyomo/core/base/units_container.py
+++ b/pyomo/core/base/units_container.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -119,7 +119,6 @@
     value,
     native_types,
     native_numeric_types,
-    pyomo_constant_types,
 )
 from pyomo.core.expr.template_expr import IndexTemplate
 from pyomo.core.expr.visitor import ExpressionValueVisitor
@@ -127,7 +126,6 @@
 
 pint_module, pint_available = attempt_import(
     'pint',
-    defer_check=True,
     error_message=(
         'The "pint" package failed to import. '
         'This package is necessary to use Pyomo units.'
@@ -902,7 +900,7 @@ def initializeWalker(self, expr):
 
     def beforeChild(self, node, child, child_idx):
         ctype = child.__class__
-        if ctype in native_types or ctype in pyomo_constant_types:
+        if ctype in native_types:
             return False, self._pint_dimensionless
 
         if child.is_expression_type():
@@ -917,7 +915,7 @@ def beforeChild(self, node, child, child_idx):
             pint_unit = self._pyomo_units_container._get_pint_units(pyomo_unit)
             return False, pint_unit
 
-        return True, None
+        return False, self._pint_dimensionless
 
     def exitNode(self, node, data):
         """Visitor callback when moving up the expression tree.
diff --git a/pyomo/core/base/util.py b/pyomo/core/base/util.py
index 867a303395b..6a3885cedfb 100644
--- a/pyomo/core/base/util.py
+++ b/pyomo/core/base/util.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/base/var.py b/pyomo/core/base/var.py
index f54cea98a9e..38d1d38a864 100644
--- a/pyomo/core/base/var.py
+++ b/pyomo/core/base/var.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,12 +9,12 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['Var', '_VarData', '_GeneralVarData', 'VarList', 'SimpleVar', 'ScalarVar']
-
+from __future__ import annotations
 import logging
 import sys
 from pyomo.common.pyomo_typing import overload
 from weakref import ref as weakref_ref
+from typing import Union, Type
 
 from pyomo.common.deprecation import RenamedClass
 from pyomo.common.log import is_debug_set
@@ -29,7 +29,6 @@
     value,
     is_potentially_variable,
     native_numeric_types,
-    native_types,
 )
 from pyomo.core.base.component import ComponentData, ModelComponentFactory
 from pyomo.core.base.global_set import UnindexedComponent_index
@@ -44,7 +43,6 @@
     DefaultInitializer,
     BoundInitializer,
 )
-from pyomo.core.base.misc import apply_indexed_rule
 from pyomo.core.base.set import (
     Reals,
     Binary,
@@ -54,7 +52,6 @@
     integer_global_set_ids,
 )
 from pyomo.core.base.units_container import units
-from pyomo.core.base.util import is_functor
 
 logger = logging.getLogger('pyomo.core')
 
@@ -66,8 +63,7 @@
     + [(_, False) for _ in integer_global_set_ids]
 )
 _VARDATA_API = (
-    # including 'domain' runs afoul of logic in Block._add_implicit_sets()
-    # 'domain',
+    'domain',
     'bounds',
     'lower',
     'upper',
@@ -89,241 +85,11 @@
     'value',
     'stale',
     'fixed',
+    ('__call__', "access property 'value' on"),
 )
 
 
-class _VarData(ComponentData, NumericValue):
-    """This class defines the abstract interface for a single variable.
-
-    Note that this "abstract" class is not intended to be directly
-    instantiated.
-
-    """
-
-    __slots__ = ()
-
-    #
-    # Interface
-    #
-
-    def has_lb(self):
-        """Returns :const:`False` when the lower bound is
-        :const:`None` or negative infinity"""
-        return self.lb is not None
-
-    def has_ub(self):
-        """Returns :const:`False` when the upper bound is
-        :const:`None` or positive infinity"""
-        return self.ub is not None
-
-    # TODO: deprecate this?  Properties are generally preferred over "set*()"
-    def setlb(self, val):
-        """
-        Set the lower bound for this variable after validating that
-        the value is fixed (or None).
-        """
-        self.lower = val
-
-    # TODO: deprecate this?  Properties are generally preferred over "set*()"
-    def setub(self, val):
-        """
-        Set the upper bound for this variable after validating that
-        the value is fixed (or None).
-        """
-        self.upper = val
-
-    @property
-    def bounds(self):
-        """Returns (or set) the tuple (lower bound, upper bound).
-
-        This returns the current (numeric) values of the lower and upper
-        bounds as a tuple.  If there is no bound, returns None (and not
-        +/-inf)
-
-        """
-        return self.lb, self.ub
-
-    @bounds.setter
-    def bounds(self, val):
-        self.lower, self.upper = val
-
-    @property
-    def lb(self):
-        """Return (or set) the numeric value of the variable lower bound."""
-        lb = value(self.lower)
-        return None if lb == _ninf else lb
-
-    @lb.setter
-    def lb(self, val):
-        self.lower = val
-
-    @property
-    def ub(self):
-        """Return (or set) the numeric value of the variable upper bound."""
-        ub = value(self.upper)
-        return None if ub == _inf else ub
-
-    @ub.setter
-    def ub(self, val):
-        self.upper = val
-
-    def is_integer(self):
-        """Returns True when the domain is a contiguous integer range."""
-        _id = id(self.domain)
-        if _id in _known_global_real_domains:
-            return not _known_global_real_domains[_id]
-        _interval = self.domain.get_interval()
-        if _interval is None:
-            return False
-        # Note: it is not sufficient to just check the step: the
-        # starting / ending points must be integers (or not specified)
-        start, stop, step = _interval
-        return (
-            step == 1
-            and (start is None or int(start) == start)
-            and (stop is None or int(stop) == stop)
-        )
-
-    def is_binary(self):
-        """Returns True when the domain is restricted to Binary values."""
-        domain = self.domain
-        if domain is Binary:
-            return True
-        if id(domain) in _known_global_real_domains:
-            return False
-        return domain.get_interval() == (0, 1, 1)
-
-    def is_continuous(self):
-        """Returns True when the domain is a continuous real range"""
-        _id = id(self.domain)
-        if _id in _known_global_real_domains:
-            return _known_global_real_domains[_id]
-        _interval = self.domain.get_interval()
-        return _interval is not None and _interval[2] == 0
-
-    def is_fixed(self):
-        """Returns True if this variable is fixed, otherwise returns False."""
-        return self.fixed
-
-    def is_constant(self):
-        """Returns False because this is not a constant in an expression."""
-        return False
-
-    def is_variable_type(self):
-        """Returns True because this is a variable."""
-        return True
-
-    def is_potentially_variable(self):
-        """Returns True because this is a variable."""
-        return True
-
-    def _compute_polynomial_degree(self, result):
-        """
-        If the variable is fixed, it represents a constant
-        is a polynomial with degree 0. Otherwise, it has
-        degree 1. This method is used in expressions to
-        compute polynomial degree.
-        """
-        if self.fixed:
-            return 0
-        return 1
-
-    def clear(self):
-        self.value = None
-
-    def __call__(self, exception=True):
-        """Compute the value of this variable."""
-        return self.value
-
-    #
-    # Abstract Interface
-    #
-
-    def set_value(self, val, skip_validation=False):
-        """Set the current variable value."""
-        raise NotImplementedError
-
-    @property
-    def value(self):
-        """Return (or set) the value for this variable."""
-        raise NotImplementedError
-
-    @property
-    def domain(self):
-        """Return (or set) the domain for this variable."""
-        raise NotImplementedError
-
-    @property
-    def lower(self):
-        """Return (or set) an expression for the variable lower bound."""
-        raise NotImplementedError
-
-    @property
-    def upper(self):
-        """Return (or set) an expression for the variable upper bound."""
-        raise NotImplementedError
-
-    @property
-    def fixed(self):
-        """Return (or set) the fixed indicator for this variable.
-
-        Alias for :meth:`is_fixed` / :meth:`fix` / :meth:`unfix`.
-
-        """
-        raise NotImplementedError
-
-    @property
-    def stale(self):
-        """The stale status for this variable.
-
-        Variables are "stale" if their current value was not updated as
-        part of the most recent model update.  A "model update" can be
-        one of several things: a solver invocation, loading a previous
-        solution, or manually updating a non-stale :class:`Var` value.
-
-        Returns
-        -------
-        bool
-
-        Notes
-        -----
-        Fixed :class:`Var` objects will be stale after invoking a solver
-        (as their value was not updated by the solver).
-
-        Updating a stale :class:`Var` value will not cause other
-        variable values to be come stale.  However, updating the first
-        non-stale :class:`Var` value after a solve or solution load
-        *will* cause all other variables to be marked as stale
-
-        """
-        raise NotImplementedError
-
-    def fix(self, value=NOTSET, skip_validation=False):
-        """Fix the value of this variable (treat as nonvariable)
-
-        This sets the :attr:`fixed` indicator to True.  If ``value`` is
-        provided, the value (and the ``skip_validation`` flag) are first
-        passed to :meth:`set_value()`.
-
-        """
-        self.fixed = True
-        if value is not NOTSET:
-            self.set_value(value, skip_validation)
-
-    def unfix(self):
-        """Unfix this variable (treat as variable in solver interfaces)
-
-        This sets the :attr:`fixed` indicator to False.
-
-        """
-        self.fixed = False
-
-    def free(self):
-        """Alias for :meth:`unfix`"""
-        return self.unfix()
-
-
-class _GeneralVarData(_VarData):
+class VarData(ComponentData, NumericValue):
     """This class defines the data for a single variable."""
 
     __slots__ = ('_value', '_lb', '_ub', '_domain', '_fixed', '_stale')
@@ -333,7 +99,7 @@ def __init__(self, component=None):
         #
         # These lines represent in-lining of the
         # following constructors:
-        #   - _VarData
+        #   - VarData
         #   - ComponentData
         #   - NumericValue
         self._component = weakref_ref(component) if (component is not None) else None
@@ -364,10 +130,6 @@ def copy(cls, src):
         self._index = src._index
         return self
 
-    #
-    # Abstract Interface
-    #
-
     def set_value(self, val, skip_validation=False):
         """Set the current variable value.
 
@@ -390,17 +152,22 @@ def set_value(self, val, skip_validation=False):
         #
         # Check if this Var has units: assigning dimensionless
         # values to a variable with units should be an error
-        if type(val) not in native_numeric_types:
-            if self.parent_component()._units is not None:
-                _src_magnitude = value(val)
+        if val.__class__ in native_numeric_types:
+            pass
+        elif self.parent_component()._units is not None:
+            _src_magnitude = value(val)
+            # Note: value() could have just registered a new numeric type
+            if val.__class__ in native_numeric_types:
+                val = _src_magnitude
+            else:
                 _src_units = units.get_units(val)
                 val = units.convert_value(
                     num_value=_src_magnitude,
                     from_units=_src_units,
                     to_units=self.parent_component()._units,
                 )
-            else:
-                val = value(val)
+        else:
+            val = value(val)
 
         if not skip_validation:
             if val not in self.domain:
@@ -423,20 +190,28 @@ def set_value(self, val, skip_validation=False):
 
     @property
     def value(self):
+        """Return (or set) the value for this variable."""
         return self._value
 
     @value.setter
     def value(self, val):
         self.set_value(val)
 
+    def __call__(self, exception=True):
+        """Compute the value of this variable."""
+        return self._value
+
     @property
     def domain(self):
+        """Return (or set) the domain for this variable."""
         return self._domain
 
     @domain.setter
     def domain(self, domain):
         try:
-            self._domain = SetInitializer(domain)(self.parent_block(), self.index())
+            self._domain = SetInitializer(domain)(
+                self.parent_block(), self.index(), self
+            )
         except:
             logger.error(
                 "%s is not a valid domain. Variable domains must be an "
@@ -445,9 +220,42 @@ def domain(self, domain):
             )
             raise
 
-    @_VarData.bounds.getter
+    def has_lb(self):
+        """Returns :const:`False` when the lower bound is
+        :const:`None` or negative infinity"""
+        return self.lb is not None
+
+    def has_ub(self):
+        """Returns :const:`False` when the upper bound is
+        :const:`None` or positive infinity"""
+        return self.ub is not None
+
+    # TODO: deprecate this?  Properties are generally preferred over "set*()"
+    def setlb(self, val):
+        """
+        Set the lower bound for this variable after validating that
+        the value is fixed (or None).
+        """
+        self.lower = val
+
+    # TODO: deprecate this?  Properties are generally preferred over "set*()"
+    def setub(self, val):
+        """
+        Set the upper bound for this variable after validating that
+        the value is fixed (or None).
+        """
+        self.upper = val
+
+    @property
     def bounds(self):
-        # Custom implementation of _VarData.bounds to avoid unnecessary
+        """Returns (or set) the tuple (lower bound, upper bound).
+
+        This returns the current (numeric) values of the lower and upper
+        bounds as a tuple.  If there is no bound, returns None (and not
+        +/-inf)
+
+        """
+        # Custom implementation of lb / ub to avoid unnecessary
         # expression generation and duplicate calls to domain.bounds()
         domain_lb, domain_ub = self.domain.bounds()
         # lb is the tighter of the domain and bounds
@@ -488,10 +296,14 @@ def bounds(self):
                 ub = min(ub, domain_ub)
         return lb, ub
 
-    @_VarData.lb.getter
+    @bounds.setter
+    def bounds(self, val):
+        self.lower, self.upper = val
+
+    @property
     def lb(self):
-        # Custom implementation of _VarData.lb to avoid unnecessary
-        # expression generation
+        """Return (or set) the numeric value of the variable lower bound."""
+        # Note: Implementation avoids unnecessary expression generation
         domain_lb, domain_ub = self.domain.bounds()
         # lb is the tighter of the domain and bounds
         lb = self._lb
@@ -513,10 +325,14 @@ def lb(self):
                 lb = max(lb, domain_lb)
         return lb
 
-    @_VarData.ub.getter
+    @lb.setter
+    def lb(self, val):
+        self.lower = val
+
+    @property
     def ub(self):
-        # Custom implementation of _VarData.ub to avoid unnecessary
-        # expression generation
+        """Return (or set) the numeric value of the variable upper bound."""
+        # Note: implementation avoids unnecessary expression generation
         domain_lb, domain_ub = self.domain.bounds()
         # ub is the tighter of the domain and bounds
         ub = self._ub
@@ -538,6 +354,10 @@ def ub(self):
                 ub = min(ub, domain_ub)
         return ub
 
+    @ub.setter
+    def ub(self, val):
+        self.upper = val
+
     @property
     def lower(self):
         """Return (or set) an expression for the variable lower bound.
@@ -594,8 +414,37 @@ def get_units(self):
         # component if not scalar
         return self.parent_component()._units
 
+    def fix(self, value=NOTSET, skip_validation=False):
+        """Fix the value of this variable (treat as nonvariable)
+
+        This sets the :attr:`fixed` indicator to True.  If ``value`` is
+        provided, the value (and the ``skip_validation`` flag) are first
+        passed to :meth:`set_value()`.
+
+        """
+        self.fixed = True
+        if value is not NOTSET:
+            self.set_value(value, skip_validation)
+
+    def unfix(self):
+        """Unfix this variable (treat as variable in solver interfaces)
+
+        This sets the :attr:`fixed` indicator to False.
+
+        """
+        self.fixed = False
+
+    def free(self):
+        """Alias for :meth:`unfix`"""
+        return self.unfix()
+
     @property
     def fixed(self):
+        """Return (or set) the fixed indicator for this variable.
+
+        Alias for :meth:`is_fixed` / :meth:`fix` / :meth:`unfix`.
+
+        """
         return self._fixed
 
     @fixed.setter
@@ -604,6 +453,28 @@ def fixed(self, val):
 
     @property
     def stale(self):
+        """The stale status for this variable.
+
+        Variables are "stale" if their current value was not updated as
+        part of the most recent model update.  A "model update" can be
+        one of several things: a solver invocation, loading a previous
+        solution, or manually updating a non-stale :class:`Var` value.
+
+        Returns
+        -------
+        bool
+
+        Notes
+        -----
+        Fixed :class:`Var` objects will be stale after invoking a solver
+        (as their value was not updated by the solver).
+
+        Updating a stale :class:`Var` value will not cause other
+        variable values to be come stale.  However, updating the first
+        non-stale :class:`Var` value after a solve or solution load
+        *will* cause all other variables to be marked as stale
+
+        """
         return StaleFlagManager.is_stale(self._stale)
 
     @stale.setter
@@ -613,11 +484,70 @@ def stale(self, val):
         else:
             self._stale = StaleFlagManager.get_flag(0)
 
-    # Note: override the base class definition to avoid a call through a
-    # property
+    def is_integer(self):
+        """Returns True when the domain is a contiguous integer range."""
+        _id = id(self.domain)
+        if _id in _known_global_real_domains:
+            return not _known_global_real_domains[_id]
+        _interval = self.domain.get_interval()
+        if _interval is None:
+            return False
+        # Note: it is not sufficient to just check the step: the
+        # starting / ending points must be integers (or not specified)
+        start, stop, step = _interval
+        return (
+            step == 1
+            and (start is None or int(start) == start)
+            and (stop is None or int(stop) == stop)
+        )
+
+    def is_binary(self):
+        """Returns True when the domain is restricted to Binary values."""
+        domain = self.domain
+        if domain is Binary:
+            return True
+        if id(domain) in _known_global_real_domains:
+            return False
+        return domain.get_interval() == (0, 1, 1)
+
+    def is_continuous(self):
+        """Returns True when the domain is a continuous real range"""
+        _id = id(self.domain)
+        if _id in _known_global_real_domains:
+            return _known_global_real_domains[_id]
+        _interval = self.domain.get_interval()
+        return _interval is not None and _interval[2] == 0
+
     def is_fixed(self):
+        """Returns True if this variable is fixed, otherwise returns False."""
         return self._fixed
 
+    def is_constant(self):
+        """Returns False because this is not a constant in an expression."""
+        return False
+
+    def is_variable_type(self):
+        """Returns True because this is a variable."""
+        return True
+
+    def is_potentially_variable(self):
+        """Returns True because this is a variable."""
+        return True
+
+    def clear(self):
+        self.value = None
+
+    def _compute_polynomial_degree(self, result):
+        """
+        If the variable is fixed, it represents a constant
+        is a polynomial with degree 0. Otherwise, it has
+        degree 1. This method is used in expressions to
+        compute polynomial degree.
+        """
+        if self._fixed:
+            return 0
+        return 1
+
     def _process_bound(self, val, bound_type):
         if type(val) in native_numeric_types or val is None:
             # TODO: warn/error: check if this Var has units: assigning
@@ -640,6 +570,16 @@ def _process_bound(self, val, bound_type):
         return val
 
 
+class _VarData(metaclass=RenamedClass):
+    __renamed__new_class__ = VarData
+    __renamed__version__ = '6.7.2'
+
+
+class _GeneralVarData(metaclass=RenamedClass):
+    __renamed__new_class__ = VarData
+    __renamed__version__ = '6.7.2'
+
+
 @ModelComponentFactory.register("Decision variables.")
 class Var(IndexedComponent, IndexedComponent_NDArrayMixin):
     """A numeric variable, which may be defined over an index.
@@ -665,7 +605,16 @@ class Var(IndexedComponent, IndexedComponent_NDArrayMixin):
         doc (str, optional): Text describing this component.
     """
 
-    _ComponentDataClass = _GeneralVarData
+    _ComponentDataClass = VarData
+
+    @overload
+    def __new__(cls: Type[Var], *args, **kwargs) -> Union[ScalarVar, IndexedVar]: ...
+
+    @overload
+    def __new__(cls: Type[ScalarVar], *args, **kwargs) -> ScalarVar: ...
+
+    @overload
+    def __new__(cls: Type[IndexedVar], *args, **kwargs) -> IndexedVar: ...
 
     def __new__(cls, *args, **kwargs):
         if cls is not Var:
@@ -687,7 +636,7 @@ def __init__(
         dense=True,
         units=None,
         name=None,
-        doc=None
+        doc=None,
     ): ...
 
     def __init__(self, *args, **kwargs):
@@ -763,7 +712,7 @@ def add(self, index):
 
     def construct(self, data=None):
         """
-        Construct the _VarData objects for this variable
+        Construct the VarData objects for this variable
         """
         if self._constructed:
             return
@@ -773,6 +722,10 @@ def construct(self, data=None):
         if is_debug_set(logger):
             logger.debug("Constructing Variable %s" % (self.name,))
 
+        if self._anonymous_sets is not None:
+            for _set in self._anonymous_sets:
+                _set.construct()
+
         # Note: define 'index' to avoid 'variable referenced before
         # assignment' in the error message generated in the 'except:'
         # block below.
@@ -818,7 +771,7 @@ def construct(self, data=None):
                 # initializers that are constant, we can avoid
                 # re-calling (and re-validating) the inputs in certain
                 # cases.  To support this, we will create the first
-                # _VarData and then use it as a template to initialize
+                # VarData and then use it as a template to initialize
                 # (constant portions of) every VarData so as to not
                 # repeat all the domain/bounds validation.
                 try:
@@ -853,7 +806,7 @@ def construct(self, data=None):
                         # We can directly set the attribute (not the
                         # property) because the SetInitializer ensures
                         # that the value is a proper Set.
-                        obj._domain = self._rule_domain(block, index)
+                        obj._domain = self._rule_domain(block, index, self)
                 if call_bounds_rule:
                     for index, obj in self._data.items():
                         obj.lower, obj.upper = self._rule_bounds(block, index)
@@ -890,7 +843,7 @@ def _getitem_when_not_present(self, index):
         obj._index = index
         # We can directly set the attribute (not the property) because
         # the SetInitializer ensures that the value is a proper Set.
-        obj._domain = self._rule_domain(parent, index)
+        obj._domain = self._rule_domain(parent, index, self)
         if self._rule_bounds is not None:
             obj.lower, obj.upper = self._rule_bounds(parent, index)
         if self._rule_init is not None:
@@ -936,11 +889,11 @@ def _pprint(self):
         )
 
 
-class ScalarVar(_GeneralVarData, Var):
+class ScalarVar(VarData, Var):
     """A single variable."""
 
     def __init__(self, *args, **kwd):
-        _GeneralVarData.__init__(self, component=self)
+        VarData.__init__(self, component=self)
         Var.__init__(self, *args, **kwd)
         self._index = UnindexedComponent_index
 
@@ -987,7 +940,7 @@ def fix(self, value=NOTSET, skip_validation=False):
     def unfix(self):
         """Unfix all variables in this :class:`IndexedVar` (treat as variable)
 
-        This sets the :attr:`_VarData.fixed` indicator to False for
+        This sets the :attr:`VarData.fixed` indicator to False for
         every variable in this :class:`IndexedVar`.
 
         """
@@ -1012,17 +965,17 @@ def domain(self, domain):
         try:
             domain_rule = SetInitializer(domain)
             if domain_rule.constant():
-                domain = domain_rule(self.parent_block(), None)
+                domain = domain_rule(self.parent_block(), None, self)
                 for vardata in self.values():
                     vardata._domain = domain
             elif domain_rule.contains_indices():
                 parent = self.parent_block()
                 for index in domain_rule.indices():
-                    self[index]._domain = domain_rule(parent, index)
+                    self[index]._domain = domain_rule(parent, index, self)
             else:
                 parent = self.parent_block()
                 for index, vardata in self.items():
-                    vardata._domain = domain_rule(parent, index)
+                    vardata._domain = domain_rule(parent, index, self)
         except:
             logger.error(
                 "%s is not a valid domain. Variable domains must be an "
@@ -1041,7 +994,7 @@ def domain(self, domain):
     # between potentially variable GetItemExpression objects and
     # "constant" GetItemExpression objects.  That will need to wait for
     # the expression rework [JDS; Nov 22].
-    def __getitem__(self, args):
+    def __getitem__(self, args) -> VarData:
         try:
             return super().__getitem__(args)
         except RuntimeError:
diff --git a/pyomo/core/beta/__init__.py b/pyomo/core/beta/__init__.py
index d07668534c8..a2d51d0b23e 100644
--- a/pyomo/core/beta/__init__.py
+++ b/pyomo/core/beta/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/beta/dict_objects.py b/pyomo/core/beta/dict_objects.py
index c987d0946a3..eedb3c45bf3 100644
--- a/pyomo/core/beta/dict_objects.py
+++ b/pyomo/core/beta/dict_objects.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,17 +9,15 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ()
-
 import logging
 from weakref import ref as weakref_ref
 
 from pyomo.common.log import is_debug_set
 from pyomo.core.base.set_types import Any
-from pyomo.core.base.var import IndexedVar, _VarData
-from pyomo.core.base.constraint import IndexedConstraint, _ConstraintData
-from pyomo.core.base.objective import IndexedObjective, _ObjectiveData
-from pyomo.core.base.expression import IndexedExpression, _ExpressionData
+from pyomo.core.base.var import IndexedVar, VarData
+from pyomo.core.base.constraint import IndexedConstraint, ConstraintData
+from pyomo.core.base.objective import IndexedObjective, ObjectiveData
+from pyomo.core.base.expression import IndexedExpression, ExpressionData
 
 from collections.abc import MutableMapping
 from collections.abc import Mapping
@@ -186,7 +184,7 @@ def __init__(self, *args, **kwds):
         # Constructor for ComponentDict needs to
         # go last in order to handle any initialization
         # iterable as an argument
-        ComponentDict.__init__(self, _VarData, *args, **kwds)
+        ComponentDict.__init__(self, VarData, *args, **kwds)
 
 
 class ConstraintDict(ComponentDict, IndexedConstraint):
@@ -195,7 +193,7 @@ def __init__(self, *args, **kwds):
         # Constructor for ComponentDict needs to
         # go last in order to handle any initialization
         # iterable as an argument
-        ComponentDict.__init__(self, _ConstraintData, *args, **kwds)
+        ComponentDict.__init__(self, ConstraintData, *args, **kwds)
 
 
 class ObjectiveDict(ComponentDict, IndexedObjective):
@@ -204,7 +202,7 @@ def __init__(self, *args, **kwds):
         # Constructor for ComponentDict needs to
         # go last in order to handle any initialization
         # iterable as an argument
-        ComponentDict.__init__(self, _ObjectiveData, *args, **kwds)
+        ComponentDict.__init__(self, ObjectiveData, *args, **kwds)
 
 
 class ExpressionDict(ComponentDict, IndexedExpression):
@@ -213,4 +211,4 @@ def __init__(self, *args, **kwds):
         # Constructor for ComponentDict needs to
         # go last in order to handle any initialization
         # iterable as an argument
-        ComponentDict.__init__(self, _ExpressionData, *args, **kwds)
+        ComponentDict.__init__(self, ExpressionData, *args, **kwds)
diff --git a/pyomo/core/beta/list_objects.py b/pyomo/core/beta/list_objects.py
index 2c42dfa57c8..005bfc38a1f 100644
--- a/pyomo/core/beta/list_objects.py
+++ b/pyomo/core/beta/list_objects.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,17 +9,15 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ()
-
 import logging
 from weakref import ref as weakref_ref
 
 from pyomo.common.log import is_debug_set
 from pyomo.core.base.set_types import Any
-from pyomo.core.base.var import IndexedVar, _VarData
-from pyomo.core.base.constraint import IndexedConstraint, _ConstraintData
-from pyomo.core.base.objective import IndexedObjective, _ObjectiveData
-from pyomo.core.base.expression import IndexedExpression, _ExpressionData
+from pyomo.core.base.var import IndexedVar, VarData
+from pyomo.core.base.constraint import IndexedConstraint, ConstraintData
+from pyomo.core.base.objective import IndexedObjective, ObjectiveData
+from pyomo.core.base.expression import IndexedExpression, ExpressionData
 
 from collections.abc import MutableSequence
 
@@ -234,7 +232,7 @@ def __init__(self, *args, **kwds):
         # Constructor for ComponentList needs to
         # go last in order to handle any initialization
         # iterable as an argument
-        ComponentList.__init__(self, _VarData, *args, **kwds)
+        ComponentList.__init__(self, VarData, *args, **kwds)
 
 
 class XConstraintList(ComponentList, IndexedConstraint):
@@ -243,7 +241,7 @@ def __init__(self, *args, **kwds):
         # Constructor for ComponentList needs to
         # go last in order to handle any initialization
         # iterable as an argument
-        ComponentList.__init__(self, _ConstraintData, *args, **kwds)
+        ComponentList.__init__(self, ConstraintData, *args, **kwds)
 
 
 class XObjectiveList(ComponentList, IndexedObjective):
@@ -252,7 +250,7 @@ def __init__(self, *args, **kwds):
         # Constructor for ComponentList needs to
         # go last in order to handle any initialization
         # iterable as an argument
-        ComponentList.__init__(self, _ObjectiveData, *args, **kwds)
+        ComponentList.__init__(self, ObjectiveData, *args, **kwds)
 
 
 class XExpressionList(ComponentList, IndexedExpression):
@@ -261,4 +259,4 @@ def __init__(self, *args, **kwds):
         # Constructor for ComponentList needs to
         # go last in order to handle any initialization
         # iterable as an argument
-        ComponentList.__init__(self, _ExpressionData, *args, **kwds)
+        ComponentList.__init__(self, ExpressionData, *args, **kwds)
diff --git a/pyomo/core/expr/__init__.py b/pyomo/core/expr/__init__.py
index 5e30fceeeaa..b0ad2ac4892 100644
--- a/pyomo/core/expr/__init__.py
+++ b/pyomo/core/expr/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,14 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-#
-# The definition of __all__ is a bit funky here, because we want to
-# expose symbols in pyomo.core.expr.current that are not included in
-# pyomo.core.expr.  The idea is that pyomo.core.expr provides symbols
-# that are used by general users, but pyomo.core.expr.current provides
-# symbols that are used by developers.
-#
-
 from . import (
     numvalue,
     visitor,
@@ -56,6 +48,7 @@
     #
     BooleanValue,
     BooleanConstant,
+    BooleanExpression,
     BooleanExpressionBase,
     #
     UnaryBooleanExpression,
@@ -70,6 +63,8 @@
     ExactlyExpression,
     AtMostExpression,
     AtLeastExpression,
+    AllDifferentExpression,
+    CountIfExpression,
     #
     land,
     lnot,
@@ -79,6 +74,8 @@
     exactly,
     atleast,
     atmost,
+    all_different,
+    count_if,
     implies,
 )
 from .numeric_expr import (
diff --git a/pyomo/core/expr/base.py b/pyomo/core/expr/base.py
index b74bbff4e3c..6e2066afcc5 100644
--- a/pyomo/core/expr/base.py
+++ b/pyomo/core/expr/base.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -360,7 +360,7 @@ def size(self):
         """
         return visitor.sizeof_expression(self)
 
-    def _apply_operation(self, result):  # pragma: no cover
+    def _apply_operation(self, result):
         """
         Compute the values of this node given the values of its children.
 
diff --git a/pyomo/core/expr/boolean_value.py b/pyomo/core/expr/boolean_value.py
index b9c8ece29c8..002ec91be9d 100644
--- a/pyomo/core/expr/boolean_value.py
+++ b/pyomo/core/expr/boolean_value.py
@@ -2,7 +2,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/expr/calculus/__init__.py b/pyomo/core/expr/calculus/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/core/expr/calculus/__init__.py
+++ b/pyomo/core/expr/calculus/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/core/expr/calculus/derivatives.py b/pyomo/core/expr/calculus/derivatives.py
index c9787b0e309..69fe4969938 100644
--- a/pyomo/core/expr/calculus/derivatives.py
+++ b/pyomo/core/expr/calculus/derivatives.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -39,11 +39,11 @@ def differentiate(expr, wrt=None, wrt_list=None, mode=Modes.reverse_numeric):
     ----------
     expr: pyomo.core.expr.numeric_expr.NumericExpression
         The expression to differentiate
-    wrt: pyomo.core.base.var._GeneralVarData
+    wrt: pyomo.core.base.var.VarData
         If specified, this function will return the derivative with
-        respect to wrt. wrt is normally a _GeneralVarData, but could
-        also be a _ParamData. wrt and wrt_list cannot both be specified.
-    wrt_list: list of pyomo.core.base.var._GeneralVarData
+        respect to wrt. wrt is normally a VarData, but could
+        also be a ParamData. wrt and wrt_list cannot both be specified.
+    wrt_list: list of pyomo.core.base.var.VarData
         If specified, this function will return the derivative with
         respect to each element in wrt_list.  A list will be returned
         where the values are the derivatives with respect to the
diff --git a/pyomo/core/expr/calculus/diff_with_pyomo.py b/pyomo/core/expr/calculus/diff_with_pyomo.py
index 0e3ba3cc2b2..fe3eddf1490 100644
--- a/pyomo/core/expr/calculus/diff_with_pyomo.py
+++ b/pyomo/core/expr/calculus/diff_with_pyomo.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/expr/calculus/diff_with_sympy.py b/pyomo/core/expr/calculus/diff_with_sympy.py
index 32cf60547ec..ab62fa3c307 100644
--- a/pyomo/core/expr/calculus/diff_with_sympy.py
+++ b/pyomo/core/expr/calculus/diff_with_sympy.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/expr/cnf_walker.py b/pyomo/core/expr/cnf_walker.py
index a7bf61bef5a..7b2081e5d36 100644
--- a/pyomo/core/expr/cnf_walker.py
+++ b/pyomo/core/expr/cnf_walker.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/expr/compare.py b/pyomo/core/expr/compare.py
index ec8d56896b8..4a777a9b977 100644
--- a/pyomo/core/expr/compare.py
+++ b/pyomo/core/expr/compare.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -196,7 +196,7 @@ def compare_expressions(expr1, expr2, include_named_exprs=True):
     )
     try:
         res = pn1 == pn2
-    except PyomoException:
+    except (PyomoException, AttributeError):
         res = False
     return res
 
@@ -230,10 +230,14 @@ def assertExpressionsEqual(test, a, b, include_named_exprs=True, places=None):
         test.assertEqual(len(prefix_a), len(prefix_b))
         for _a, _b in zip(prefix_a, prefix_b):
             test.assertIs(_a.__class__, _b.__class__)
-            if places is None:
-                test.assertEqual(_a, _b)
+            # If _a is nan, check _b is nan
+            if _a != _a:
+                test.assertTrue(_b != _b)
             else:
-                test.assertAlmostEqual(_a, _b, places=places)
+                if places is None:
+                    test.assertEqual(_a, _b)
+                else:
+                    test.assertAlmostEqual(_a, _b, places=places)
     except (PyomoException, AssertionError):
         test.fail(
             f"Expressions not equal:\n\t"
@@ -292,10 +296,13 @@ def assertExpressionsStructurallyEqual(
         for _a, _b in zip(prefix_a, prefix_b):
             if _a.__class__ not in native_types and _b.__class__ not in native_types:
                 test.assertIs(_a.__class__, _b.__class__)
-            if places is None:
-                test.assertEqual(_a, _b)
+            if _a != _a:
+                test.assertTrue(_b != _b)
             else:
-                test.assertAlmostEqual(_a, _b, places=places)
+                if places is None:
+                    test.assertEqual(_a, _b)
+                else:
+                    test.assertAlmostEqual(_a, _b, places=places)
     except (PyomoException, AssertionError):
         test.fail(
             f"Expressions not structurally equal:\n\t"
diff --git a/pyomo/core/expr/current.py b/pyomo/core/expr/current.py
index 0a2ff01c82a..1209dac0310 100644
--- a/pyomo/core/expr/current.py
+++ b/pyomo/core/expr/current.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/expr/expr_common.py b/pyomo/core/expr/expr_common.py
index daf86c7afc8..88065e37a2c 100644
--- a/pyomo/core/expr/expr_common.py
+++ b/pyomo/core/expr/expr_common.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/expr/expr_errors.py b/pyomo/core/expr/expr_errors.py
index e33a6cbbbd7..b0ad816d725 100644
--- a/pyomo/core/expr/expr_errors.py
+++ b/pyomo/core/expr/expr_errors.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/expr/logical_expr.py b/pyomo/core/expr/logical_expr.py
index f2d3e110166..9519b02a43b 100644
--- a/pyomo/core/expr/logical_expr.py
+++ b/pyomo/core/expr/logical_expr.py
@@ -2,7 +2,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -10,7 +10,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-
 import types
 from itertools import islice
 
@@ -36,6 +35,7 @@
 from .base import ExpressionBase
 from .boolean_value import BooleanValue, BooleanConstant
 from .expr_common import _and, _or, _equiv, _inv, _xor, _impl, ExpressionType
+from .numeric_expr import NumericExpression
 
 import operator
 
@@ -183,12 +183,62 @@ def _flattened(args):
                 yield arg
 
 
+def _flattened_boolean_args(args):
+    """Flatten any potentially indexed arguments and check that they are
+    Boolean-valued."""
+    for arg in args:
+        if arg.__class__ in native_types:
+            myiter = (arg,)
+        elif isinstance(arg, (types.GeneratorType, list)):
+            myiter = arg
+        elif arg.is_indexed():
+            myiter = arg.values()
+        else:
+            myiter = (arg,)
+        for _argdata in myiter:
+            if _argdata.__class__ in native_logical_types:
+                yield _argdata
+            elif hasattr(_argdata, 'is_logical_type') and _argdata.is_logical_type():
+                yield _argdata
+            elif isinstance(_argdata, BooleanValue):
+                yield _argdata
+            else:
+                raise ValueError(
+                    "Non-Boolean-valued argument '%s' encountered when constructing "
+                    "expression of Boolean arguments" % arg
+                )
+
+
+def _flattened_numeric_args(args):
+    """Flatten any potentially indexed arguments and check that they are
+    numeric."""
+    for arg in args:
+        if arg.__class__ in native_types:
+            myiter = (arg,)
+        elif isinstance(arg, (types.GeneratorType, list)):
+            myiter = arg
+        elif arg.is_indexed():
+            myiter = arg.values()
+        else:
+            myiter = (arg,)
+        for _argdata in myiter:
+            if _argdata.__class__ in native_numeric_types:
+                yield _argdata
+            elif hasattr(_argdata, 'is_numeric_type') and _argdata.is_numeric_type():
+                yield _argdata
+            else:
+                raise ValueError(
+                    "Non-numeric argument '%s' encountered when constructing "
+                    "expression with numeric arguments" % arg
+                )
+
+
 def land(*args):
     """
     Construct an AndExpression between passed arguments.
     """
     result = AndExpression([])
-    for argdata in _flattened(args):
+    for argdata in _flattened_boolean_args(args):
         result = result.add(argdata)
     return result
 
@@ -198,7 +248,7 @@ def lor(*args):
     Construct an OrExpression between passed arguments.
     """
     result = OrExpression([])
-    for argdata in _flattened(args):
+    for argdata in _flattened_boolean_args(args):
         result = result.add(argdata)
     return result
 
@@ -211,7 +261,7 @@ def exactly(n, *args):
     Usage: exactly(2, m.Y1, m.Y2, m.Y3, ...)
 
     """
-    result = ExactlyExpression([n] + list(_flattened(args)))
+    result = ExactlyExpression([n] + list(_flattened_boolean_args(args)))
     return result
 
 
@@ -223,7 +273,7 @@ def atmost(n, *args):
     Usage: atmost(2, m.Y1, m.Y2, m.Y3, ...)
 
     """
-    result = AtMostExpression([n] + list(_flattened(args)))
+    result = AtMostExpression([n] + list(_flattened_boolean_args(args)))
     return result
 
 
@@ -235,10 +285,30 @@ def atleast(n, *args):
     Usage: atleast(2, m.Y1, m.Y2, m.Y3, ...)
 
     """
-    result = AtLeastExpression([n] + list(_flattened(args)))
+    result = AtLeastExpression([n] + list(_flattened_boolean_args(args)))
     return result
 
 
+def all_different(*args):
+    """Creates a new AllDifferentExpression
+
+    Requires all of the arguments to take on a different value
+
+    Usage: all_different(m.X1, m.X2, ...)
+    """
+    return AllDifferentExpression(list(_flattened_numeric_args(args)))
+
+
+def count_if(*args):
+    """Creates a new CountIfExpression
+
+    Counts the number of True-valued arguments
+
+    Usage: count_if(m.Y1, m.Y2, ...)
+    """
+    return CountIfExpression(list(_flattened_boolean_args(args)))
+
+
 class UnaryBooleanExpression(BooleanExpression):
     """
     Abstract class for single-argument logical expressions.
@@ -511,4 +581,54 @@ def _apply_operation(self, result):
         return sum(result[1:]) >= result[0]
 
 
+class AllDifferentExpression(NaryBooleanExpression):
+    """
+    Logical expression that all of the N child statements have different values.
+    All arguments are expected to be discrete-valued.
+    """
+
+    __slots__ = ()
+
+    PRECEDENCE = None
+
+    def getname(self, *arg, **kwd):
+        return 'all_different'
+
+    def _to_string(self, values, verbose, smap):
+        return "all_different(%s)" % (", ".join(values))
+
+    def _apply_operation(self, result):
+        last = None
+        # we know these are integer-valued, so we can just sort them an make
+        # sure that no adjacent pairs have the same value.
+        for val in sorted(result):
+            if last == val:
+                return False
+            last = val
+        return True
+
+
+class CountIfExpression(NumericExpression):
+    """
+    Logical expression that returns the number of True child statements.
+    All arguments are expected to be Boolean-valued.
+    """
+
+    __slots__ = ()
+    PRECEDENCE = None
+
+    # NumericExpression assumes binary operator, so we have to override.
+    def nargs(self):
+        return len(self._args_)
+
+    def getname(self, *arg, **kwd):
+        return 'count_if'
+
+    def _to_string(self, values, verbose, smap):
+        return "count_if(%s)" % (", ".join(values))
+
+    def _apply_operation(self, result):
+        return sum(value(r) for r in result)
+
+
 special_boolean_atom_types = {ExactlyExpression, AtMostExpression, AtLeastExpression}
diff --git a/pyomo/core/expr/ndarray.py b/pyomo/core/expr/ndarray.py
index fcbe5477a08..41514c91153 100644
--- a/pyomo/core/expr/ndarray.py
+++ b/pyomo/core/expr/ndarray.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/expr/numeric_expr.py b/pyomo/core/expr/numeric_expr.py
index 0a300474790..21896c63219 100644
--- a/pyomo/core/expr/numeric_expr.py
+++ b/pyomo/core/expr/numeric_expr.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -722,7 +722,7 @@ def args(self):
     @deprecated(
         'The implicit recasting of a "not potentially variable" '
         'expression node to a potentially variable one is no '
-        'longer supported (this violates that immutability '
+        'longer supported (this violates the immutability '
         'promise for Pyomo5 expression trees).',
         version='6.4.3',
     )
@@ -1234,9 +1234,11 @@ class LinearExpression(SumExpression):
     """An expression object for linear polynomials.
 
     This is a derived :py:class`SumExpression` that guarantees all
-    arguments are either not potentially variable (e.g., native types,
-    Params, or NPV expressions) OR :py:class:`MonomialTermExpression`
-    objects.
+    arguments are one of the following types:
+
+      - not potentially variable (e.g., native types, Params, or NPV expressions)
+      - :py:class:`MonomialTermExpression`
+      - :py:class:`VarData`
 
     Args:
         args (tuple): Children nodes
@@ -1253,7 +1255,7 @@ def __init__(self, args=None, constant=None, linear_coefs=None, linear_vars=None
 
         You can specify `args` OR (`constant`, `linear_coefs`, and
         `linear_vars`).  If `args` is provided, it should be a list that
-        contains only constants, NPV objects/expressions, or
+        contains only constants, NPV objects/expressions, variables, or
         :py:class:`MonomialTermExpression` objects.  Alternatively, you
         can specify the constant, the list of linear_coefs and the list
         of linear_vars separately.  Note that these lists are NOT
@@ -1298,8 +1300,14 @@ def _build_cache(self):
             if arg.__class__ is MonomialTermExpression:
                 coef.append(arg._args_[0])
                 var.append(arg._args_[1])
-            else:
+            elif arg.__class__ in native_numeric_types:
+                const += arg
+            elif not arg.is_potentially_variable():
                 const += arg
+            else:
+                assert arg.is_potentially_variable()
+                coef.append(1)
+                var.append(arg)
         LinearExpression._cache = (self, const, coef, var)
 
     @property
@@ -1325,7 +1333,7 @@ def create_node_with_local_data(self, args, classtype=None):
             classtype = self.__class__
         if type(args) is not list:
             args = list(args)
-        for i, arg in enumerate(args):
+        for arg in args:
             if arg.__class__ in self._allowable_linear_expr_arg_types:
                 # 99% of the time, the arg type hasn't changed
                 continue
@@ -1336,8 +1344,7 @@ def create_node_with_local_data(self, args, classtype=None):
                 # NPV expressions are OK
                 pass
             elif arg.is_variable_type():
-                # vars are OK, but need to be mapped to monomial terms
-                args[i] = MonomialTermExpression((1, arg))
+                # vars are OK
                 continue
             else:
                 # For anything else, convert this to a general sum
@@ -1820,7 +1827,7 @@ def _add_native_param(a, b):
 def _add_native_var(a, b):
     if not a:
         return b
-    return LinearExpression([a, MonomialTermExpression((1, b))])
+    return LinearExpression([a, b])
 
 
 def _add_native_monomial(a, b):
@@ -1871,7 +1878,7 @@ def _add_npv_param(a, b):
 
 
 def _add_npv_var(a, b):
-    return LinearExpression([a, MonomialTermExpression((1, b))])
+    return LinearExpression([a, b])
 
 
 def _add_npv_monomial(a, b):
@@ -1929,7 +1936,7 @@ def _add_param_var(a, b):
         a = a.value
         if not a:
             return b
-    return LinearExpression([a, MonomialTermExpression((1, b))])
+    return LinearExpression([a, b])
 
 
 def _add_param_monomial(a, b):
@@ -1972,11 +1979,11 @@ def _add_param_other(a, b):
 def _add_var_native(a, b):
     if not b:
         return a
-    return LinearExpression([MonomialTermExpression((1, a)), b])
+    return LinearExpression([a, b])
 
 
 def _add_var_npv(a, b):
-    return LinearExpression([MonomialTermExpression((1, a)), b])
+    return LinearExpression([a, b])
 
 
 def _add_var_param(a, b):
@@ -1984,21 +1991,19 @@ def _add_var_param(a, b):
         b = b.value
         if not b:
             return a
-    return LinearExpression([MonomialTermExpression((1, a)), b])
+    return LinearExpression([a, b])
 
 
 def _add_var_var(a, b):
-    return LinearExpression(
-        [MonomialTermExpression((1, a)), MonomialTermExpression((1, b))]
-    )
+    return LinearExpression([a, b])
 
 
 def _add_var_monomial(a, b):
-    return LinearExpression([MonomialTermExpression((1, a)), b])
+    return LinearExpression([a, b])
 
 
 def _add_var_linear(a, b):
-    return b._trunc_append(MonomialTermExpression((1, a)))
+    return b._trunc_append(a)
 
 
 def _add_var_sum(a, b):
@@ -2033,7 +2038,7 @@ def _add_monomial_param(a, b):
 
 
 def _add_monomial_var(a, b):
-    return LinearExpression([a, MonomialTermExpression((1, b))])
+    return LinearExpression([a, b])
 
 
 def _add_monomial_monomial(a, b):
@@ -2076,7 +2081,7 @@ def _add_linear_param(a, b):
 
 
 def _add_linear_var(a, b):
-    return a._trunc_append(MonomialTermExpression((1, b)))
+    return a._trunc_append(b)
 
 
 def _add_linear_monomial(a, b):
@@ -2283,8 +2288,11 @@ def _iadd_mutablenpvsum_mutable(a, b):
 def _iadd_mutablenpvsum_native(a, b):
     if not b:
         return a
-    a._args_.append(b)
-    a._nargs += 1
+    if a._args_ and a._args_[-1].__class__ in native_numeric_types:
+        a._args_[-1] += b
+    else:
+        a._args_.append(b)
+        a._nargs += 1
     return a
 
 
@@ -2296,9 +2304,7 @@ def _iadd_mutablenpvsum_npv(a, b):
 
 def _iadd_mutablenpvsum_param(a, b):
     if b.is_constant():
-        b = b.value
-        if not b:
-            return a
+        return _iadd_mutablesum_native(a, b.value)
     a._args_.append(b)
     a._nargs += 1
     return a
@@ -2379,8 +2385,11 @@ def _iadd_mutablelinear_mutable(a, b):
 def _iadd_mutablelinear_native(a, b):
     if not b:
         return a
-    a._args_.append(b)
-    a._nargs += 1
+    if a._args_ and a._args_[-1].__class__ in native_numeric_types:
+        a._args_[-1] += b
+    else:
+        a._args_.append(b)
+        a._nargs += 1
     return a
 
 
@@ -2392,16 +2401,14 @@ def _iadd_mutablelinear_npv(a, b):
 
 def _iadd_mutablelinear_param(a, b):
     if b.is_constant():
-        b = b.value
-        if not b:
-            return a
+        return _iadd_mutablesum_native(a, b.value)
     a._args_.append(b)
     a._nargs += 1
     return a
 
 
 def _iadd_mutablelinear_var(a, b):
-    a._args_.append(MonomialTermExpression((1, b)))
+    a._args_.append(b)
     a._nargs += 1
     return a
 
@@ -2478,8 +2485,11 @@ def _iadd_mutablesum_mutable(a, b):
 def _iadd_mutablesum_native(a, b):
     if not b:
         return a
-    a._args_.append(b)
-    a._nargs += 1
+    if a._args_ and a._args_[-1].__class__ in native_numeric_types:
+        a._args_[-1] += b
+    else:
+        a._args_.append(b)
+        a._nargs += 1
     return a
 
 
@@ -2491,9 +2501,7 @@ def _iadd_mutablesum_npv(a, b):
 
 def _iadd_mutablesum_param(a, b):
     if b.is_constant():
-        b = b.value
-        if not b:
-            return a
+        return _iadd_mutablesum_native(a, b.value)
     a._args_.append(b)
     a._nargs += 1
     return a
diff --git a/pyomo/core/expr/numvalue.py b/pyomo/core/expr/numvalue.py
index 6c605b080a3..96e2f50b3f8 100644
--- a/pyomo/core/expr/numvalue.py
+++ b/pyomo/core/expr/numvalue.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,21 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = (
-    'value',
-    'is_constant',
-    'is_fixed',
-    'is_variable_type',
-    'is_potentially_variable',
-    'NumericValue',
-    'ZeroConstant',
-    'native_numeric_types',
-    'native_types',
-    'nonpyomo_leaf_types',
-    'polynomial_degree',
-)
-
-import collections
 import sys
 import logging
 
@@ -34,7 +19,6 @@
 )
 from pyomo.core.expr.expr_common import ExpressionType
 from pyomo.core.expr.numeric_expr import NumericValue
-import pyomo.common.numeric_types as _numeric_types
 
 # TODO: update Pyomo to import these objects from common.numeric_types
 #   (and not from here)
@@ -44,7 +28,7 @@
     native_numeric_types,
     native_integer_types,
     native_logical_types,
-    pyomo_constant_types,
+    _pyomo_constant_types,
     check_if_numeric_type,
     value,
 )
@@ -60,6 +44,16 @@
     "be treated as if they were bool (as was the case for the other "
     "native_*_types sets).  Users likely should use native_logical_types.",
 )
+relocated_module_attribute(
+    'pyomo_constant_types',
+    'pyomo.common.numeric_types._pyomo_constant_types',
+    version='6.7.2',
+    f_globals=globals(),
+    msg="The pyomo_constant_types set will be removed in the future: the set "
+    "contained only NumericConstant and _PythonCallbackFunctionID, and provided "
+    "no meaningful value to clients or walkers.  Users should likely handle "
+    "these types in the same manner as immutable Params.",
+)
 relocated_module_attribute(
     'RegisterNumericType',
     'pyomo.common.numeric_types.RegisterNumericType',
@@ -101,7 +95,7 @@
 ##------------------------------------------------------------------------
 
 
-class NonNumericValue(object):
+class NonNumericValue(PyomoObject):
     """An object that contains a non-numeric value
 
     Constructor Arguments:
@@ -116,6 +110,9 @@ def __init__(self, value):
     def __str__(self):
         return str(self.value)
 
+    def __call__(self, exception=None):
+        return self.value
+
 
 nonpyomo_leaf_types.add(NonNumericValue)
 
@@ -426,7 +423,7 @@ def pprint(self, ostream=None, verbose=False):
         ostream.write(str(self))
 
 
-pyomo_constant_types.add(NumericConstant)
+_pyomo_constant_types.add(NumericConstant)
 
 # We use as_numeric() so that the constant is also in the cache
 ZeroConstant = as_numeric(0)
diff --git a/pyomo/core/expr/relational_expr.py b/pyomo/core/expr/relational_expr.py
index 6e4831d5c0c..c80fdd4930a 100644
--- a/pyomo/core/expr/relational_expr.py
+++ b/pyomo/core/expr/relational_expr.py
@@ -2,7 +2,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/expr/symbol_map.py b/pyomo/core/expr/symbol_map.py
index ab497c217a8..ebcf9b2953e 100644
--- a/pyomo/core/expr/symbol_map.py
+++ b/pyomo/core/expr/symbol_map.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/expr/sympy_tools.py b/pyomo/core/expr/sympy_tools.py
index 7b494a610cd..d751ca35e5f 100644
--- a/pyomo/core/expr/sympy_tools.py
+++ b/pyomo/core/expr/sympy_tools.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,13 +9,13 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 import operator
-import sys
+from math import prod as _prod
 
+import pyomo.core.expr as EXPR
 from pyomo.common import DeveloperError
 from pyomo.common.collections import ComponentMap
 from pyomo.common.dependencies import attempt_import
 from pyomo.common.errors import NondifferentiableError
-import pyomo.core.expr as EXPR
 from pyomo.core.expr.numvalue import value, native_types
 
 #
@@ -28,6 +28,25 @@
 _functionMap = {}
 
 
+def _nondifferentiable(x):
+    if type(x[1]) is tuple:
+        # sympy >= 1.3 returns tuples (var, order)
+        wrt = x[1][0]
+    else:
+        # early versions of sympy returned the bare var
+        wrt = x[1]
+    raise NondifferentiableError(
+        "The sub-expression '%s' is not differentiable with respect to %s" % (x[0], wrt)
+    )
+
+
+def _external_fcn(*x):
+    raise TypeError(
+        "Expressions containing external functions are not convertible to "
+        f"sympy expressions (found 'f{x}')"
+    )
+
+
 def _configure_sympy(sympy, available):
     if not available:
         return
@@ -113,37 +132,6 @@ def _configure_sympy(sympy, available):
 sympy, sympy_available = attempt_import('sympy', callback=_configure_sympy)
 
 
-if sys.version_info[:2] < (3, 8):
-
-    def _prod(args):
-        ans = 1
-        for arg in args:
-            ans *= arg
-        return ans
-
-else:
-    from math import prod as _prod
-
-
-def _nondifferentiable(x):
-    if type(x[1]) is tuple:
-        # sympy >= 1.3 returns tuples (var, order)
-        wrt = x[1][0]
-    else:
-        # early versions of sympy returned the bare var
-        wrt = x[1]
-    raise NondifferentiableError(
-        "The sub-expression '%s' is not differentiable with respect to %s" % (x[0], wrt)
-    )
-
-
-def _external_fcn(*x):
-    raise TypeError(
-        "Expressions containing external functions are not convertible to "
-        f"sympy expressions (found 'f{x}')"
-    )
-
-
 class PyomoSympyBimap(object):
     def __init__(self):
         self.pyomo2sympy = ComponentMap()
@@ -175,10 +163,11 @@ def sympyVars(self):
 
 
 class Pyomo2SympyVisitor(EXPR.StreamBasedExpressionVisitor):
-    def __init__(self, object_map):
+    def __init__(self, object_map, keep_mutable_parameters=False):
         sympy.Add  # this ensures _configure_sympy gets run
         super(Pyomo2SympyVisitor, self).__init__()
         self.object_map = object_map
+        self.keep_mutable_parameters = keep_mutable_parameters
 
     def initializeWalker(self, expr):
         return self.beforeChild(None, expr, None)
@@ -212,6 +201,8 @@ def beforeChild(self, node, child, child_idx):
         #
         # Everything else is a constant...
         #
+        if self.keep_mutable_parameters and child.is_parameter_type() and child.mutable:
+            return False, self.object_map.getSympySymbol(child)
         return False, value(child)
 
 
@@ -245,13 +236,15 @@ def beforeChild(self, node, child, child_idx):
         return True, None
 
 
-def sympyify_expression(expr):
+def sympyify_expression(expr, keep_mutable_parameters=False):
     """Convert a Pyomo expression to a Sympy expression"""
     #
     # Create the visitor and call it.
     #
     object_map = PyomoSympyBimap()
-    visitor = Pyomo2SympyVisitor(object_map)
+    visitor = Pyomo2SympyVisitor(
+        object_map, keep_mutable_parameters=keep_mutable_parameters
+    )
     return object_map, visitor.walk_expression(expr)
 
 
diff --git a/pyomo/core/expr/taylor_series.py b/pyomo/core/expr/taylor_series.py
index 2c72f8bcfbc..2658dd36ff5 100644
--- a/pyomo/core/expr/taylor_series.py
+++ b/pyomo/core/expr/taylor_series.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.core.expr import identify_variables, value, differentiate
 import logging
 import math
diff --git a/pyomo/core/expr/template_expr.py b/pyomo/core/expr/template_expr.py
index fd6294f2289..d30046e9d82 100644
--- a/pyomo/core/expr/template_expr.py
+++ b/pyomo/core/expr/template_expr.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -19,11 +19,12 @@
 from pyomo.core.expr.base import ExpressionBase, ExpressionArgs_Mixin, NPV_Mixin
 from pyomo.core.expr.logical_expr import BooleanExpression
 from pyomo.core.expr.numeric_expr import (
+    ARG_TYPE,
     NumericExpression,
-    SumExpression,
     Numeric_NPV_Mixin,
+    SumExpression,
+    mutable_expression,
     register_arg_type,
-    ARG_TYPE,
     _balanced_parens,
 )
 from pyomo.core.expr.numvalue import (
@@ -116,18 +117,10 @@ def _to_string(self, values, verbose, smap):
         return "%s[%s]" % (values[0], ','.join(values[1:]))
 
     def _resolve_template(self, args):
-        return args[0].__getitem__(tuple(args[1:]))
+        return args[0].__getitem__(args[1:])
 
     def _apply_operation(self, result):
-        args = tuple(
-            (
-                arg
-                if arg.__class__ in native_types or not arg.is_numeric_type()
-                else value(arg)
-            )
-            for arg in result[1:]
-        )
-        return result[0].__getitem__(tuple(result[1:]))
+        return result[0].__getitem__(result[1:])
 
 
 class Numeric_GetItemExpression(GetItemExpression, NumericExpression):
@@ -258,8 +251,8 @@ def nargs(self):
         return 2
 
     def _apply_operation(self, result):
-        assert len(result) == 2
-        return getattr(result[0], result[1])
+        obj, attr = result
+        return getattr(obj, attr)
 
     def _to_string(self, values, verbose, smap):
         assert len(values) == 2
@@ -273,7 +266,7 @@ def _to_string(self, values, verbose, smap):
         return "%s.%s" % (values[0], attr)
 
     def _resolve_template(self, args):
-        return getattr(*tuple(args))
+        return getattr(*args)
 
 
 class Numeric_GetAttrExpression(GetAttrExpression, NumericExpression):
@@ -521,7 +514,15 @@ def _to_string(self, values, verbose, smap):
             return 'SUM(%s %s)' % (val, iterStr)
 
     def _resolve_template(self, args):
-        return SumExpression(args)
+        with mutable_expression() as e:
+            for arg in args:
+                e += arg
+        if e.nargs() > 1:
+            return e
+        elif not e.nargs():
+            return 0
+        else:
+            return e.arg(0)
 
 
 class IndexTemplate(NumericValue):
diff --git a/pyomo/core/expr/visitor.py b/pyomo/core/expr/visitor.py
index f1cd3b7bde6..08015f8b42c 100644
--- a/pyomo/core/expr/visitor.py
+++ b/pyomo/core/expr/visitor.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -1373,22 +1373,125 @@ def identify_components(expr, component_types):
 # =====================================================
 
 
-class _VariableVisitor(SimpleExpressionVisitor):
-    def __init__(self):
-        self.seen = set()
+class _VariableVisitor(StreamBasedExpressionVisitor):
+    def __init__(self, include_fixed=False, named_expression_cache=None):
+        """Visitor that collects all unique variables participating in an
+        expression
 
-    def visit(self, node):
-        if node.__class__ in nonpyomo_leaf_types:
-            return
+        Args:
+            include_fixed (bool): Whether to include fixed variables
+            named_expression_cache (optional, dict): Dict mapping ids of named
+                expressions to a tuple of the list of all variables and the
+                set of all variable ids contained in the named expression.
 
-        if node.is_variable_type():
-            if id(node) in self.seen:
-                return
-            self.seen.add(id(node))
-            return node
+        """
+        super().__init__()
+        self._include_fixed = include_fixed
+        if named_expression_cache is None:
+            # This cache will map named expression ids to the
+            # tuple: ([variables], {variable ids})
+            named_expression_cache = {}
+        self._named_expression_cache = named_expression_cache
+        # Stack of active named expressions. This holds the id of
+        # expressions we are currently in.
+        self._active_named_expressions = []
 
+    def initializeWalker(self, expr):
+        if expr.__class__ in native_types:
+            return False, []
+        elif expr.is_named_expression_type():
+            eid = id(expr)
+            if eid in self._named_expression_cache:
+                # If we were given a named expression that is already cached,
+                # just do nothing and return the expression's variables
+                variables, var_set = self._named_expression_cache[eid]
+                return False, variables
+            else:
+                # We were given a named expression that is not cached.
+                # Initialize data structures and add this expression to the
+                # stack. This expression will get popped in exitNode.
+                self._variables = []
+                self._seen = set()
+                self._named_expression_cache[eid] = [], set()
+                self._active_named_expressions.append(eid)
+                return True, expr
+        elif expr.is_variable_type():
+            return False, [expr]
+        else:
+            self._variables = []
+            self._seen = set()
+            return True, expr
 
-def identify_variables(expr, include_fixed=True):
+    def beforeChild(self, parent, child, index):
+        if child.__class__ in native_types:
+            return False, None
+        elif child.is_named_expression_type():
+            eid = id(child)
+            if eid in self._named_expression_cache:
+                # We have already encountered this named expression. We just add
+                # the cached variables to our list and don't descend.
+                if self._active_named_expressions:
+                    # If we are in another named expression, we update the
+                    # parent expression's cache. We don't need to update the
+                    # global list as we will do this when we exit the active
+                    # named expression.
+                    parent_eid = self._active_named_expressions[-1]
+                    variables, var_set = self._named_expression_cache[parent_eid]
+                else:
+                    # If we are not in a named expression, we update the global
+                    # list.
+                    variables = self._variables
+                    var_set = self._seen
+                for var in self._named_expression_cache[eid][0]:
+                    if id(var) not in var_set:
+                        var_set.add(id(var))
+                        variables.append(var)
+                return False, None
+            else:
+                # If we are descending into a new named expression, initialize
+                # a cache to store the expression's local variables.
+                self._named_expression_cache[id(child)] = ([], set())
+                self._active_named_expressions.append(id(child))
+                return True, None
+        elif child.is_variable_type() and (self._include_fixed or not child.fixed):
+            if self._active_named_expressions:
+                # If we are in a named expression, add new variables to the cache.
+                eid = self._active_named_expressions[-1]
+                variables, var_set = self._named_expression_cache[eid]
+            else:
+                variables = self._variables
+                var_set = self._seen
+            if id(child) not in var_set:
+                var_set.add(id(child))
+                variables.append(child)
+            return False, None
+        else:
+            return True, None
+
+    def exitNode(self, node, data):
+        if node.is_named_expression_type():
+            # If we are returning from a named expression, we have at least one
+            # active named expression. We must make sure that we properly
+            # handle the variables for the named expression we just exited.
+            eid = self._active_named_expressions.pop()
+            if self._active_named_expressions:
+                # If we still are in a named expression, we update that expression's
+                # cache with any new variables encountered.
+                parent_eid = self._active_named_expressions[-1]
+                variables, var_set = self._named_expression_cache[parent_eid]
+            else:
+                variables = self._variables
+                var_set = self._seen
+            for var in self._named_expression_cache[eid][0]:
+                if id(var) not in var_set:
+                    var_set.add(id(var))
+                    variables.append(var)
+
+    def finalizeResult(self, result):
+        return self._variables
+
+
+def identify_variables(expr, include_fixed=True, named_expression_cache=None):
     """
     A generator that yields a sequence of variables
     in an expression tree.
@@ -1402,22 +1505,13 @@ def identify_variables(expr, include_fixed=True):
     Yields:
         Each variable that is found.
     """
-    visitor = _VariableVisitor()
-    if include_fixed:
-        for v in visitor.xbfs_yield_leaves(expr):
-            if isinstance(v, tuple):
-                yield from v
-            else:
-                yield v
-    else:
-        for v in visitor.xbfs_yield_leaves(expr):
-            if isinstance(v, tuple):
-                for v_i in v:
-                    if not v_i.is_fixed():
-                        yield v_i
-            else:
-                if not v.is_fixed():
-                    yield v
+    if named_expression_cache is None:
+        named_expression_cache = {}
+    visitor = _VariableVisitor(
+        named_expression_cache=named_expression_cache, include_fixed=include_fixed
+    )
+    variables = visitor.walk_expression(expr)
+    yield from variables
 
 
 # =====================================================
diff --git a/pyomo/core/kernel/__init__.py b/pyomo/core/kernel/__init__.py
index 28a329109fc..ffe0beee080 100644
--- a/pyomo/core/kernel/__init__.py
+++ b/pyomo/core/kernel/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/kernel/base.py b/pyomo/core/kernel/base.py
index 2c0af56bc10..d599c76f6a1 100644
--- a/pyomo/core/kernel/base.py
+++ b/pyomo/core/kernel/base.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/kernel/block.py b/pyomo/core/kernel/block.py
index fd779578fc4..8ba332e5545 100644
--- a/pyomo/core/kernel/block.py
+++ b/pyomo/core/kernel/block.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/kernel/component_map.py b/pyomo/core/kernel/component_map.py
index 501854ad972..5b5b6e9a6f2 100644
--- a/pyomo/core/kernel/component_map.py
+++ b/pyomo/core/kernel/component_map.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/kernel/component_set.py b/pyomo/core/kernel/component_set.py
index b0eb3507347..969b8b86372 100644
--- a/pyomo/core/kernel/component_set.py
+++ b/pyomo/core/kernel/component_set.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/kernel/conic.py b/pyomo/core/kernel/conic.py
index 730c072d1b7..bd78ba310f4 100644
--- a/pyomo/core/kernel/conic.py
+++ b/pyomo/core/kernel/conic.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -632,7 +632,7 @@ def as_domain(cls, r, x):
         b = block()
         b.r = variable_tuple([variable(lb=0) for i in range(len(r))])
         b.x = variable()
-        b.c = _build_linking_constraints(list(r) + [x], list(b.r) + [x])
+        b.c = _build_linking_constraints(list(r) + [x], list(b.r) + [b.x])
         b.q = cls(r=b.r, x=b.x)
         return b
 
@@ -934,7 +934,7 @@ def as_domain(cls, r, x):
         b = block()
         b.r = variable_tuple([variable(lb=0) for i in range(len(r))])
         b.x = variable()
-        b.c = _build_linking_constraints(list(r) + [x], list(b.r) + [x])
+        b.c = _build_linking_constraints(list(r) + [x], list(b.r) + [b.x])
         b.q = cls(r=b.r, x=b.x)
         return b
 
diff --git a/pyomo/core/kernel/constraint.py b/pyomo/core/kernel/constraint.py
index 7c7969cb025..6aa4abc4bfe 100644
--- a/pyomo/core/kernel/constraint.py
+++ b/pyomo/core/kernel/constraint.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/kernel/container_utils.py b/pyomo/core/kernel/container_utils.py
index 7f3329aadb3..e197d0162b5 100644
--- a/pyomo/core/kernel/container_utils.py
+++ b/pyomo/core/kernel/container_utils.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/kernel/dict_container.py b/pyomo/core/kernel/dict_container.py
index b86d9c5b8f2..ae23044f8ed 100644
--- a/pyomo/core/kernel/dict_container.py
+++ b/pyomo/core/kernel/dict_container.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/kernel/expression.py b/pyomo/core/kernel/expression.py
index b375a6a89fc..a477ff9d0e3 100644
--- a/pyomo/core/kernel/expression.py
+++ b/pyomo/core/kernel/expression.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/kernel/heterogeneous_container.py b/pyomo/core/kernel/heterogeneous_container.py
index 43846673838..4783a2d3ec6 100644
--- a/pyomo/core/kernel/heterogeneous_container.py
+++ b/pyomo/core/kernel/heterogeneous_container.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/kernel/homogeneous_container.py b/pyomo/core/kernel/homogeneous_container.py
index 22a70e1edff..edec98e9736 100644
--- a/pyomo/core/kernel/homogeneous_container.py
+++ b/pyomo/core/kernel/homogeneous_container.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/kernel/list_container.py b/pyomo/core/kernel/list_container.py
index 05116797f3a..d60b0c7678d 100644
--- a/pyomo/core/kernel/list_container.py
+++ b/pyomo/core/kernel/list_container.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/kernel/matrix_constraint.py b/pyomo/core/kernel/matrix_constraint.py
index 1dc0fa7ddc3..ac0ec8e832d 100644
--- a/pyomo/core/kernel/matrix_constraint.py
+++ b/pyomo/core/kernel/matrix_constraint.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/kernel/objective.py b/pyomo/core/kernel/objective.py
index c25c86d3c09..ac6f22d07d3 100644
--- a/pyomo/core/kernel/objective.py
+++ b/pyomo/core/kernel/objective.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,15 +9,12 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
+from pyomo.common.enums import ObjectiveSense, minimize, maximize
 from pyomo.core.expr.numvalue import as_numeric
 from pyomo.core.kernel.base import _abstract_readwrite_property
 from pyomo.core.kernel.container_utils import define_simple_containers
 from pyomo.core.kernel.expression import IExpression
 
-# Constants used to define the optimization sense
-minimize = 1
-maximize = -1
-
 
 class IObjective(IExpression):
     """
@@ -84,14 +81,7 @@ def sense(self):
     @sense.setter
     def sense(self, sense):
         """Set the sense (direction) of this objective."""
-        if (sense == minimize) or (sense == maximize):
-            self._sense = sense
-        else:
-            raise ValueError(
-                "Objective sense must be set to one of: "
-                "[minimize (%s), maximize (%s)]. Invalid "
-                "value: %s'" % (minimize, maximize, sense)
-            )
+        self._sense = ObjectiveSense(sense)
 
 
 # inserts class definitions for simple _tuple, _list, and
diff --git a/pyomo/core/kernel/parameter.py b/pyomo/core/kernel/parameter.py
index 1d22072435d..d4dd6336c69 100644
--- a/pyomo/core/kernel/parameter.py
+++ b/pyomo/core/kernel/parameter.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/kernel/piecewise_library/__init__.py b/pyomo/core/kernel/piecewise_library/__init__.py
index d275b52367e..c4d2a751632 100644
--- a/pyomo/core/kernel/piecewise_library/__init__.py
+++ b/pyomo/core/kernel/piecewise_library/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/kernel/piecewise_library/transforms.py b/pyomo/core/kernel/piecewise_library/transforms.py
index f00e57c199d..bc6cb0f51ad 100644
--- a/pyomo/core/kernel/piecewise_library/transforms.py
+++ b/pyomo/core/kernel/piecewise_library/transforms.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/kernel/piecewise_library/transforms_nd.py b/pyomo/core/kernel/piecewise_library/transforms_nd.py
index f1ea67e8d4b..2c4c8a1f1f2 100644
--- a/pyomo/core/kernel/piecewise_library/transforms_nd.py
+++ b/pyomo/core/kernel/piecewise_library/transforms_nd.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/kernel/piecewise_library/util.py b/pyomo/core/kernel/piecewise_library/util.py
index e65502b1a12..23975d87596 100644
--- a/pyomo/core/kernel/piecewise_library/util.py
+++ b/pyomo/core/kernel/piecewise_library/util.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/kernel/register_numpy_types.py b/pyomo/core/kernel/register_numpy_types.py
index 5f7812354d9..b3405645d97 100644
--- a/pyomo/core/kernel/register_numpy_types.py
+++ b/pyomo/core/kernel/register_numpy_types.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -45,10 +45,12 @@
     # Historically, the lists included several numpy aliases
     numpy_int_names.extend(('int_', 'intc', 'intp'))
     numpy_int.extend((numpy.int_, numpy.intc, numpy.intp))
-    numpy_float_names.append('float_')
-    numpy_float.append(numpy.float_)
-    numpy_complex_names.append('complex_')
-    numpy_complex.append(numpy.complex_)
+    if hasattr(numpy, 'float_'):
+        numpy_float_names.append('float_')
+        numpy_float.append(numpy.float_)
+    if hasattr(numpy, 'complex_'):
+        numpy_complex_names.append('complex_')
+        numpy_complex.append(numpy.complex_)
 
 # Re-build the old numpy_* lists
 for t in native_boolean_types:
diff --git a/pyomo/core/kernel/set_types.py b/pyomo/core/kernel/set_types.py
index efe5965946a..5915f0d64b3 100644
--- a/pyomo/core/kernel/set_types.py
+++ b/pyomo/core/kernel/set_types.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/kernel/sos.py b/pyomo/core/kernel/sos.py
index cb8d8ea4930..1845343f526 100644
--- a/pyomo/core/kernel/sos.py
+++ b/pyomo/core/kernel/sos.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/kernel/suffix.py b/pyomo/core/kernel/suffix.py
index 77079364703..56e13a371a3 100644
--- a/pyomo/core/kernel/suffix.py
+++ b/pyomo/core/kernel/suffix.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/kernel/tuple_container.py b/pyomo/core/kernel/tuple_container.py
index f717fe0350a..83aab49e5db 100644
--- a/pyomo/core/kernel/tuple_container.py
+++ b/pyomo/core/kernel/tuple_container.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/kernel/variable.py b/pyomo/core/kernel/variable.py
index ff54bcb2fca..61324b3dc0f 100644
--- a/pyomo/core/kernel/variable.py
+++ b/pyomo/core/kernel/variable.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/plugins/__init__.py b/pyomo/core/plugins/__init__.py
index f763881c50c..23407cd77ef 100644
--- a/pyomo/core/plugins/__init__.py
+++ b/pyomo/core/plugins/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/plugins/transform/__init__.py b/pyomo/core/plugins/transform/__init__.py
index 7d37c706542..21e762047ca 100644
--- a/pyomo/core/plugins/transform/__init__.py
+++ b/pyomo/core/plugins/transform/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/plugins/transform/add_slack_vars.py b/pyomo/core/plugins/transform/add_slack_vars.py
index 6906b033aab..39903384729 100644
--- a/pyomo/core/plugins/transform/add_slack_vars.py
+++ b/pyomo/core/plugins/transform/add_slack_vars.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -23,7 +23,6 @@
 from pyomo.core.plugins.transform.hierarchy import NonIsomorphicTransformation
 from pyomo.common.config import ConfigBlock, ConfigValue
 from pyomo.core.base import ComponentUID
-from pyomo.core.base.constraint import _ConstraintData
 from pyomo.common.deprecation import deprecation_warning
 
 
@@ -42,7 +41,7 @@ def target_list(x):
         # [ESJ 07/15/2020] We have to just pass it through because we need the
         # instance in order to be able to do anything about it...
         return [x]
-    elif isinstance(x, (Constraint, _ConstraintData)):
+    elif getattr(x, 'ctype', None) is Constraint:
         return [x]
     elif hasattr(x, '__iter__'):
         ans = []
@@ -53,7 +52,7 @@ def target_list(x):
                     deprecation_msg = None
                 # same as above...
                 ans.append(i)
-            elif isinstance(i, (Constraint, _ConstraintData)):
+            elif getattr(i, 'ctype', None) is Constraint:
                 ans.append(i)
             else:
                 raise ValueError(
diff --git a/pyomo/core/plugins/transform/discrete_vars.py b/pyomo/core/plugins/transform/discrete_vars.py
index cfb1c5e144f..35729e76517 100644
--- a/pyomo/core/plugins/transform/discrete_vars.py
+++ b/pyomo/core/plugins/transform/discrete_vars.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/plugins/transform/eliminate_fixed_vars.py b/pyomo/core/plugins/transform/eliminate_fixed_vars.py
index 1048b957e08..934228afd7c 100644
--- a/pyomo/core/plugins/transform/eliminate_fixed_vars.py
+++ b/pyomo/core/plugins/transform/eliminate_fixed_vars.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -11,7 +11,7 @@
 
 from pyomo.core.expr import ExpressionBase, as_numeric
 from pyomo.core import Constraint, Objective, TransformationFactory
-from pyomo.core.base.var import Var, _VarData
+from pyomo.core.base.var import Var, VarData
 from pyomo.core.util import sequence
 from pyomo.core.plugins.transform.hierarchy import IsomorphicTransformation
 
@@ -77,7 +77,7 @@ def _fix_vars(self, expr, model):
             if isinstance(expr._args[i], ExpressionBase):
                 _args.append(self._fix_vars(expr._args[i], model))
             elif (
-                isinstance(expr._args[i], Var) or isinstance(expr._args[i], _VarData)
+                isinstance(expr._args[i], Var) or isinstance(expr._args[i], VarData)
             ) and expr._args[i].fixed:
                 if expr._args[i].value != 0.0:
                     _args.append(as_numeric(expr._args[i].value))
diff --git a/pyomo/core/plugins/transform/equality_transform.py b/pyomo/core/plugins/transform/equality_transform.py
index e0cc463e238..99291c2227c 100644
--- a/pyomo/core/plugins/transform/equality_transform.py
+++ b/pyomo/core/plugins/transform/equality_transform.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -66,7 +66,7 @@ def _create_using(self, model, **kwds):
             con = equality.__getattribute__(con_name)
 
             #
-            # Get all _ConstraintData objects
+            # Get all ConstraintData objects
             #
             # We need to get the keys ahead of time because we are modifying
             # con._data on-the-fly.
@@ -104,7 +104,7 @@ def _create_using(self, model, **kwds):
                     con.add(ub_name, new_expr)
 
                 # Since we explicitly `continue` for equality constraints, we
-                # can safely remove the old _ConstraintData object
+                # can safely remove the old ConstraintData object
                 del con._data[ndx]
 
         return equality.create()
diff --git a/pyomo/core/plugins/transform/expand_connectors.py b/pyomo/core/plugins/transform/expand_connectors.py
index 8fe14318669..82ec546e593 100644
--- a/pyomo/core/plugins/transform/expand_connectors.py
+++ b/pyomo/core/plugins/transform/expand_connectors.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -25,7 +25,7 @@
     Var,
     SortComponents,
 )
-from pyomo.core.base.connector import _ConnectorData, ScalarConnector
+from pyomo.core.base.connector import ConnectorData, ScalarConnector
 
 
 @TransformationFactory.register(
@@ -69,7 +69,7 @@ def _apply_to(self, instance, **kwds):
         # The set of connectors found in the current constraint
         found = ComponentSet()
 
-        connector_types = set([ScalarConnector, _ConnectorData])
+        connector_types = set([ScalarConnector, ConnectorData])
         for constraint in instance.component_data_objects(
             Constraint, sort=SortComponents.deterministic
         ):
diff --git a/pyomo/core/plugins/transform/hierarchy.py b/pyomo/core/plugins/transform/hierarchy.py
index a7667fc028a..86338d17f88 100644
--- a/pyomo/core/plugins/transform/hierarchy.py
+++ b/pyomo/core/plugins/transform/hierarchy.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/plugins/transform/logical_to_linear.py b/pyomo/core/plugins/transform/logical_to_linear.py
index f4107b8a32c..da69ca113bd 100644
--- a/pyomo/core/plugins/transform/logical_to_linear.py
+++ b/pyomo/core/plugins/transform/logical_to_linear.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """Transformation from BooleanVar and LogicalConstraint to Binary and
 Constraints."""
 
@@ -18,7 +29,7 @@
     BooleanVarList,
     SortComponents,
 )
-from pyomo.core.base.block import _BlockData
+from pyomo.core.base.block import BlockData
 from pyomo.core.base.boolean_var import _DeprecatedImplicitAssociatedBinaryVariable
 from pyomo.core.expr.cnf_walker import to_cnf
 from pyomo.core.expr import (
@@ -89,7 +100,7 @@ def _apply_to(self, model, **kwds):
             # the GDP will be solved, and it would be wrong to assume that a GDP
             # will *necessarily* be solved as an algebraic model. The star
             # example of not doing so being GDPopt.)
-            if t.ctype is Block or isinstance(t, _BlockData):
+            if t.ctype is Block or isinstance(t, BlockData):
                 self._transform_block(t, model, new_var_lists, transBlocks)
             elif t.ctype is LogicalConstraint:
                 if t.is_indexed():
@@ -274,7 +285,7 @@ class CnfToLinearVisitor(StreamBasedExpressionVisitor):
     """Convert CNF logical constraint to linear constraints.
 
     Expected expression node types: AndExpression, OrExpression, NotExpression,
-    AtLeastExpression, AtMostExpression, ExactlyExpression, _BooleanVarData
+    AtLeastExpression, AtMostExpression, ExactlyExpression, BooleanVarData
 
     """
 
@@ -361,7 +372,7 @@ def beforeChild(self, node, child, child_idx):
         if child.is_expression_type():
             return True, None
 
-        # Only thing left should be _BooleanVarData
+        # Only thing left should be BooleanVarData
         #
         # TODO: After the expr_multiple_dispatch is merged, this should
         # be switched to using as_numeric.
diff --git a/pyomo/core/plugins/transform/model.py b/pyomo/core/plugins/transform/model.py
index 99c1d21c9a0..8fe828854ce 100644
--- a/pyomo/core/plugins/transform/model.py
+++ b/pyomo/core/plugins/transform/model.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -16,10 +16,17 @@
 # because we may support an explicit matrix representation for models.
 #
 
+from pyomo.common.deprecation import deprecated
 from pyomo.core.base import Objective, Constraint
 import array
 
 
+@deprecated(
+    "to_standard_form() is deprecated.  "
+    "Please use WriterFactory('compile_standard_form')",
+    version='6.7.3',
+    remove_in='6.8.0',
+)
 def to_standard_form(self):
     """
     Produces a standard-form representation of the model. Returns
@@ -55,8 +62,8 @@ def to_standard_form(self):
     # N.B. Structure hierarchy:
     #
     # active_components: {class: {attr_name: object}}
-    # object -> Constraint: ._data: {ndx: _ConstraintData}
-    # _ConstraintData: .lower, .body, .upper
+    # object -> Constraint: ._data: {ndx: ConstraintData}
+    # ConstraintData: .lower, .body, .upper
     #
     # So, altogether, we access a lower bound via
     #
diff --git a/pyomo/core/plugins/transform/nonnegative_transform.py b/pyomo/core/plugins/transform/nonnegative_transform.py
index b32b7b1efc0..d123e68cb2e 100644
--- a/pyomo/core/plugins/transform/nonnegative_transform.py
+++ b/pyomo/core/plugins/transform/nonnegative_transform.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/plugins/transform/radix_linearization.py b/pyomo/core/plugins/transform/radix_linearization.py
index b7ff3375a76..3cfde28db3c 100644
--- a/pyomo/core/plugins/transform/radix_linearization.py
+++ b/pyomo/core/plugins/transform/radix_linearization.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -21,7 +21,7 @@
     Block,
     RangeSet,
 )
-from pyomo.core.base.var import _VarData
+from pyomo.core.base.var import VarData
 
 import logging
 
@@ -268,8 +268,8 @@ def _collect_bilinear(self, expr, bilin, quad):
                     self._collect_bilinear(e, bilin, quad)
                 # No need to check denominator, as this is poly_degree==2
                 return
-            if not isinstance(expr._numerator[0], _VarData) or not isinstance(
-                expr._numerator[1], _VarData
+            if not isinstance(expr._numerator[0], VarData) or not isinstance(
+                expr._numerator[1], VarData
             ):
                 raise RuntimeError("Cannot yet handle complex subexpressions")
             if expr._numerator[0] is expr._numerator[1]:
@@ -280,7 +280,7 @@ def _collect_bilinear(self, expr, bilin, quad):
         if type(expr) is PowExpression and value(expr._args[1]) == 2:
             # Note: directly testing the value of the exponent above is
             # safe: we have already verified that this expression is
-            # polynominal, so the exponent must be constant.
+            # polynomial, so the exponent must be constant.
             tmp = ProductExpression()
             tmp._numerator = [expr._args[0], expr._args[0]]
             tmp._denominator = []
diff --git a/pyomo/core/plugins/transform/relax_integrality.py b/pyomo/core/plugins/transform/relax_integrality.py
index 06dd2faba77..40cf74ddbcc 100644
--- a/pyomo/core/plugins/transform/relax_integrality.py
+++ b/pyomo/core/plugins/transform/relax_integrality.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/plugins/transform/scaling.py b/pyomo/core/plugins/transform/scaling.py
index 0883455f9de..11d4ac8c493 100644
--- a/pyomo/core/plugins/transform/scaling.py
+++ b/pyomo/core/plugins/transform/scaling.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -10,16 +10,7 @@
 #  ___________________________________________________________________________
 
 from pyomo.common.collections import ComponentMap
-from pyomo.core.base import (
-    Block,
-    Var,
-    Constraint,
-    Objective,
-    _ConstraintData,
-    _ObjectiveData,
-    Suffix,
-    value,
-)
+from pyomo.core.base import Block, Var, Constraint, Objective, Suffix, value
 from pyomo.core.plugins.transform.hierarchy import Transformation
 from pyomo.core.base import TransformationFactory
 from pyomo.core.base.suffix import SuffixFinder
@@ -197,7 +188,7 @@ def _apply_to(self, model, rename=True):
                 already_scaled.add(id(c))
                 # perform the constraint/objective scaling and variable sub
                 scaling_factor = component_scaling_factor_map[c]
-                if isinstance(c, _ConstraintData):
+                if c.ctype is Constraint:
                     body = scaling_factor * replace_expressions(
                         expr=c.body,
                         substitution_map=variable_substitution_dict,
@@ -226,7 +217,7 @@ def _apply_to(self, model, rename=True):
                     else:
                         c.set_value((lower, body, upper))
 
-                elif isinstance(c, _ObjectiveData):
+                elif c.ctype is Objective:
                     c.expr = scaling_factor * replace_expressions(
                         expr=c.expr,
                         substitution_map=variable_substitution_dict,
diff --git a/pyomo/core/plugins/transform/standard_form.py b/pyomo/core/plugins/transform/standard_form.py
index 54df13fc49d..ffc382a2cf7 100644
--- a/pyomo/core/plugins/transform/standard_form.py
+++ b/pyomo/core/plugins/transform/standard_form.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/plugins/transform/util.py b/pyomo/core/plugins/transform/util.py
index bba8adfbc0f..9719b1f38d9 100644
--- a/pyomo/core/plugins/transform/util.py
+++ b/pyomo/core/plugins/transform/util.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/pyomoobject.py b/pyomo/core/pyomoobject.py
index 692db444f84..3bf6de37489 100644
--- a/pyomo/core/pyomoobject.py
+++ b/pyomo/core/pyomoobject.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/staleflag.py b/pyomo/core/staleflag.py
index 7d0dddef0dd..da90032a03c 100644
--- a/pyomo/core/staleflag.py
+++ b/pyomo/core/staleflag.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/__init__.py b/pyomo/core/tests/__init__.py
index 0dc08cc5aea..761a6e6c44c 100644
--- a/pyomo/core/tests/__init__.py
+++ b/pyomo/core/tests/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/data/__init__.py b/pyomo/core/tests/data/__init__.py
index 21b3abf0760..a73865ee112 100644
--- a/pyomo/core/tests/data/__init__.py
+++ b/pyomo/core/tests/data/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/data/test_odbc_ini.py b/pyomo/core/tests/data/test_odbc_ini.py
index e7152181645..43584fe3ca9 100644
--- a/pyomo/core/tests/data/test_odbc_ini.py
+++ b/pyomo/core/tests/data/test_odbc_ini.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/diet/__init__.py b/pyomo/core/tests/diet/__init__.py
index 3e98344ba07..717247051c4 100644
--- a/pyomo/core/tests/diet/__init__.py
+++ b/pyomo/core/tests/diet/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/diet/test_diet.py b/pyomo/core/tests/diet/test_diet.py
index d92f0a024ba..9e11907179e 100644
--- a/pyomo/core/tests/diet/test_diet.py
+++ b/pyomo/core/tests/diet/test_diet.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/examples/__init__.py b/pyomo/core/tests/examples/__init__.py
index 602516fcb56..c5ecc4ee437 100644
--- a/pyomo/core/tests/examples/__init__.py
+++ b/pyomo/core/tests/examples/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/examples/pmedian.py b/pyomo/core/tests/examples/pmedian.py
index 5176f8bad18..c476f01bd17 100644
--- a/pyomo/core/tests/examples/pmedian.py
+++ b/pyomo/core/tests/examples/pmedian.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/examples/pmedian1.py b/pyomo/core/tests/examples/pmedian1.py
index 5aeec502f7c..8e11383116b 100644
--- a/pyomo/core/tests/examples/pmedian1.py
+++ b/pyomo/core/tests/examples/pmedian1.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/examples/pmedian2.py b/pyomo/core/tests/examples/pmedian2.py
index 8a908f7d661..88a9666fe41 100644
--- a/pyomo/core/tests/examples/pmedian2.py
+++ b/pyomo/core/tests/examples/pmedian2.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/examples/pmedian4.py b/pyomo/core/tests/examples/pmedian4.py
index 98dd90f3e8f..101ee3e7c46 100644
--- a/pyomo/core/tests/examples/pmedian4.py
+++ b/pyomo/core/tests/examples/pmedian4.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/examples/pmedian_concrete.py b/pyomo/core/tests/examples/pmedian_concrete.py
new file mode 100644
index 00000000000..a6a1859df23
--- /dev/null
+++ b/pyomo/core/tests/examples/pmedian_concrete.py
@@ -0,0 +1,70 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import math
+from pyomo.environ import (
+    ConcreteModel,
+    Param,
+    RangeSet,
+    Var,
+    Reals,
+    Binary,
+    PositiveIntegers,
+)
+
+
+def _cost_rule(model, n, m):
+    # We will assume costs are an arbitrary function of the indices
+    return math.sin(n * 2.33333 + m * 7.99999)
+
+
+def create_model(n=3, m=3, p=2):
+    model = ConcreteModel(name="M1")
+
+    model.N = Param(initialize=n, within=PositiveIntegers)
+    model.M = Param(initialize=m, within=PositiveIntegers)
+    model.P = Param(initialize=p, within=RangeSet(1, model.N), mutable=True)
+
+    model.Locations = RangeSet(1, model.N)
+    model.Customers = RangeSet(1, model.M)
+
+    model.cost = Param(
+        model.Locations, model.Customers, initialize=_cost_rule, within=Reals
+    )
+    model.serve_customer_from_location = Var(
+        model.Locations, model.Customers, bounds=(0.0, 1.0)
+    )
+    model.select_location = Var(model.Locations, within=Binary)
+
+    @model.Objective()
+    def obj(model):
+        return sum(
+            model.cost[n, m] * model.serve_customer_from_location[n, m]
+            for n in model.Locations
+            for m in model.Customers
+        )
+
+    @model.Constraint(model.Customers)
+    def single_x(model, m):
+        return (
+            sum(model.serve_customer_from_location[n, m] for n in model.Locations)
+            == 1.0
+        )
+
+    @model.Constraint(model.Locations, model.Customers)
+    def bound_y(model, n, m):
+        return model.serve_customer_from_location[n, m] <= model.select_location[n]
+
+    @model.Constraint()
+    def num_facilities(model):
+        return sum(model.select_location[n] for n in model.Locations) == model.P
+
+    return model
diff --git a/pyomo/core/tests/examples/test_amplbook2.py b/pyomo/core/tests/examples/test_amplbook2.py
index fdb9cc571bf..72e3d2b4599 100644
--- a/pyomo/core/tests/examples/test_amplbook2.py
+++ b/pyomo/core/tests/examples/test_amplbook2.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/examples/test_kernel_examples.py b/pyomo/core/tests/examples/test_kernel_examples.py
index 0434d9127a3..61d0fa2527d 100644
--- a/pyomo/core/tests/examples/test_kernel_examples.py
+++ b/pyomo/core/tests/examples/test_kernel_examples.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/examples/test_pyomo.py b/pyomo/core/tests/examples/test_pyomo.py
index 64c195c0ab4..2d3a39ebdda 100644
--- a/pyomo/core/tests/examples/test_pyomo.py
+++ b/pyomo/core/tests/examples/test_pyomo.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/examples/test_tutorials.py b/pyomo/core/tests/examples/test_tutorials.py
index 3a74c1ca142..c8de003007e 100644
--- a/pyomo/core/tests/examples/test_tutorials.py
+++ b/pyomo/core/tests/examples/test_tutorials.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/transform/__init__.py b/pyomo/core/tests/transform/__init__.py
index df59aa21988..f34c7624e25 100644
--- a/pyomo/core/tests/transform/__init__.py
+++ b/pyomo/core/tests/transform/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/transform/test_add_slacks.py b/pyomo/core/tests/transform/test_add_slacks.py
index a3698b7d529..b395237b8e4 100644
--- a/pyomo/core/tests/transform/test_add_slacks.py
+++ b/pyomo/core/tests/transform/test_add_slacks.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -102,10 +102,7 @@ def checkRule1(self, m):
             self,
             cons.body,
             EXPR.LinearExpression(
-                [
-                    EXPR.MonomialTermExpression((1, m.x)),
-                    EXPR.MonomialTermExpression((-1, transBlock._slack_minus_rule1)),
-                ]
+                [m.x, EXPR.MonomialTermExpression((-1, transBlock._slack_minus_rule1))]
             ),
         )
 
@@ -118,14 +115,7 @@ def checkRule3(self, m):
         self.assertEqual(cons.lower, 0.1)
 
         assertExpressionsEqual(
-            self,
-            cons.body,
-            EXPR.LinearExpression(
-                [
-                    EXPR.MonomialTermExpression((1, m.x)),
-                    EXPR.MonomialTermExpression((1, transBlock._slack_plus_rule3)),
-                ]
-            ),
+            self, cons.body, EXPR.LinearExpression([m.x, transBlock._slack_plus_rule3])
         )
 
     def test_ub_constraint_modified(self):
@@ -154,8 +144,8 @@ def test_both_bounds_constraint_modified(self):
             cons.body,
             EXPR.LinearExpression(
                 [
-                    EXPR.MonomialTermExpression((1, m.y)),
-                    EXPR.MonomialTermExpression((1, transBlock._slack_plus_rule2)),
+                    m.y,
+                    transBlock._slack_plus_rule2,
                     EXPR.MonomialTermExpression((-1, transBlock._slack_minus_rule2)),
                 ]
             ),
@@ -184,10 +174,10 @@ def test_new_obj_created(self):
             obj.expr,
             EXPR.LinearExpression(
                 [
-                    EXPR.MonomialTermExpression((1, transBlock._slack_minus_rule1)),
-                    EXPR.MonomialTermExpression((1, transBlock._slack_plus_rule2)),
-                    EXPR.MonomialTermExpression((1, transBlock._slack_minus_rule2)),
-                    EXPR.MonomialTermExpression((1, transBlock._slack_plus_rule3)),
+                    transBlock._slack_minus_rule1,
+                    transBlock._slack_plus_rule2,
+                    transBlock._slack_minus_rule2,
+                    transBlock._slack_plus_rule3,
                 ]
             ),
         )
@@ -302,10 +292,7 @@ def checkTargetsObj(self, m):
             self,
             obj.expr,
             EXPR.LinearExpression(
-                [
-                    EXPR.MonomialTermExpression((1, transBlock._slack_minus_rule1)),
-                    EXPR.MonomialTermExpression((1, transBlock._slack_plus_rule3)),
-                ]
+                [transBlock._slack_minus_rule1, transBlock._slack_plus_rule3]
             ),
         )
 
@@ -343,7 +330,7 @@ def test_error_for_non_constraint_noniterable_target(self):
         self.assertRaisesRegex(
             ValueError,
             "Expected Constraint or list of Constraints.\n\tReceived "
-            "<class 'pyomo.core.base.var._GeneralVarData'>",
+            "<class 'pyomo.core.base.var.VarData'>",
             TransformationFactory('core.add_slack_variables').apply_to,
             m,
             targets=m.indexedVar[1],
@@ -423,9 +410,9 @@ def test_transformed_constraints_sumexpression_body(self):
             c.body,
             EXPR.LinearExpression(
                 [
-                    EXPR.MonomialTermExpression((1, m.x)),
+                    m.x,
                     EXPR.MonomialTermExpression((-2, m.y)),
-                    EXPR.MonomialTermExpression((1, transBlock._slack_plus_rule4)),
+                    transBlock._slack_plus_rule4,
                     EXPR.MonomialTermExpression((-1, transBlock._slack_minus_rule4)),
                 ]
             ),
@@ -518,15 +505,9 @@ def checkTargetObj(self, m):
             obj.expr,
             EXPR.LinearExpression(
                 [
-                    EXPR.MonomialTermExpression(
-                        (1, transBlock.component("_slack_plus_rule1[1]"))
-                    ),
-                    EXPR.MonomialTermExpression(
-                        (1, transBlock.component("_slack_plus_rule1[2]"))
-                    ),
-                    EXPR.MonomialTermExpression(
-                        (1, transBlock.component("_slack_plus_rule1[3]"))
-                    ),
+                    transBlock.component("_slack_plus_rule1[1]"),
+                    transBlock.component("_slack_plus_rule1[2]"),
+                    transBlock.component("_slack_plus_rule1[3]"),
                 ]
             ),
         )
@@ -558,14 +539,7 @@ def checkTransformedRule1(self, m, i):
             EXPR.LinearExpression(
                 [
                     EXPR.MonomialTermExpression((2, m.x[i])),
-                    EXPR.MonomialTermExpression(
-                        (
-                            1,
-                            m._core_add_slack_variables.component(
-                                "_slack_plus_rule1[%s]" % i
-                            ),
-                        )
-                    ),
+                    m._core_add_slack_variables.component("_slack_plus_rule1[%s]" % i),
                 ]
             ),
         )
diff --git a/pyomo/core/tests/transform/test_scaling.py b/pyomo/core/tests/transform/test_scaling.py
index 1cb4e886956..d0fbfab61bd 100644
--- a/pyomo/core/tests/transform/test_scaling.py
+++ b/pyomo/core/tests/transform/test_scaling.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/transform/test_transform.py b/pyomo/core/tests/transform/test_transform.py
index 7c3f17fcfec..cd1f26417a7 100644
--- a/pyomo/core/tests/transform/test_transform.py
+++ b/pyomo/core/tests/transform/test_transform.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/__init__.py b/pyomo/core/tests/unit/__init__.py
index 65e82b81c0c..85ece8d8cd5 100644
--- a/pyomo/core/tests/unit/__init__.py
+++ b/pyomo/core/tests/unit/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/kernel/__init__.py b/pyomo/core/tests/unit/kernel/__init__.py
index ff387efbd03..e5231e0f859 100644
--- a/pyomo/core/tests/unit/kernel/__init__.py
+++ b/pyomo/core/tests/unit/kernel/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/kernel/test_block.py b/pyomo/core/tests/unit/kernel/test_block.py
index a22ed4fb4b5..b21771653bb 100644
--- a/pyomo/core/tests/unit/kernel/test_block.py
+++ b/pyomo/core/tests/unit/kernel/test_block.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/kernel/test_component_map.py b/pyomo/core/tests/unit/kernel/test_component_map.py
index 6d19743c3fe..3fb8b99a9a3 100644
--- a/pyomo/core/tests/unit/kernel/test_component_map.py
+++ b/pyomo/core/tests/unit/kernel/test_component_map.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/kernel/test_component_set.py b/pyomo/core/tests/unit/kernel/test_component_set.py
index 30f2cf72716..38f17a702c1 100644
--- a/pyomo/core/tests/unit/kernel/test_component_set.py
+++ b/pyomo/core/tests/unit/kernel/test_component_set.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/kernel/test_conic.py b/pyomo/core/tests/unit/kernel/test_conic.py
index 352976a2410..bd97c13fc2e 100644
--- a/pyomo/core/tests/unit/kernel/test_conic.py
+++ b/pyomo/core/tests/unit/kernel/test_conic.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -35,6 +35,8 @@
     primal_power,
     dual_exponential,
     dual_power,
+    primal_geomean,
+    dual_geomean,
 )
 
 
@@ -784,6 +786,40 @@ def test_as_domain(self):
         x[1].value = None
 
 
+# These mosek 10 constraints can't be evaluated, pprinted, checked for convexity,
+# pickled, etc., so I won't use the _conic_tester_base for them
+class Test_primal_geomean(unittest.TestCase):
+    def test_as_domain(self):
+        b = primal_geomean.as_domain(r=[2, 3], x=6)
+        self.assertIs(type(b), block)
+        self.assertIs(type(b.q), primal_geomean)
+        self.assertIs(type(b.r), variable_tuple)
+        self.assertIs(type(b.x), variable)
+        self.assertIs(type(b.c), constraint_tuple)
+        self.assertExpressionsEqual(b.c[0].body, b.r[0])
+        self.assertExpressionsEqual(b.c[0].rhs, 2)
+        self.assertExpressionsEqual(b.c[1].body, b.r[1])
+        self.assertExpressionsEqual(b.c[1].rhs, 3)
+        self.assertExpressionsEqual(b.c[2].body, b.x)
+        self.assertExpressionsEqual(b.c[2].rhs, 6)
+
+
+class Test_dual_geomean(unittest.TestCase):
+    def test_as_domain(self):
+        b = dual_geomean.as_domain(r=[2, 3], x=6)
+        self.assertIs(type(b), block)
+        self.assertIs(type(b.q), dual_geomean)
+        self.assertIs(type(b.r), variable_tuple)
+        self.assertIs(type(b.x), variable)
+        self.assertIs(type(b.c), constraint_tuple)
+        self.assertExpressionsEqual(b.c[0].body, b.r[0])
+        self.assertExpressionsEqual(b.c[0].rhs, 2)
+        self.assertExpressionsEqual(b.c[1].body, b.r[1])
+        self.assertExpressionsEqual(b.c[1].rhs, 3)
+        self.assertExpressionsEqual(b.c[2].body, b.x)
+        self.assertExpressionsEqual(b.c[2].rhs, 6)
+
+
 class TestMisc(unittest.TestCase):
     def test_build_linking_constraints(self):
         c = _build_linking_constraints([], [])
diff --git a/pyomo/core/tests/unit/kernel/test_constraint.py b/pyomo/core/tests/unit/kernel/test_constraint.py
index f2f219cc66f..97832dd8bca 100644
--- a/pyomo/core/tests/unit/kernel/test_constraint.py
+++ b/pyomo/core/tests/unit/kernel/test_constraint.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/kernel/test_dict_container.py b/pyomo/core/tests/unit/kernel/test_dict_container.py
index e6b6f8d7aab..6ae25362bb2 100644
--- a/pyomo/core/tests/unit/kernel/test_dict_container.py
+++ b/pyomo/core/tests/unit/kernel/test_dict_container.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/kernel/test_expression.py b/pyomo/core/tests/unit/kernel/test_expression.py
index 85f8c331a46..39d3eaa463c 100644
--- a/pyomo/core/tests/unit/kernel/test_expression.py
+++ b/pyomo/core/tests/unit/kernel/test_expression.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/kernel/test_kernel.py b/pyomo/core/tests/unit/kernel/test_kernel.py
index fbff295881a..b34bcdeaadb 100644
--- a/pyomo/core/tests/unit/kernel/test_kernel.py
+++ b/pyomo/core/tests/unit/kernel/test_kernel.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/kernel/test_list_container.py b/pyomo/core/tests/unit/kernel/test_list_container.py
index 9e3ada739b2..a4641f83295 100644
--- a/pyomo/core/tests/unit/kernel/test_list_container.py
+++ b/pyomo/core/tests/unit/kernel/test_list_container.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/kernel/test_matrix_constraint.py b/pyomo/core/tests/unit/kernel/test_matrix_constraint.py
index c986e5eda96..24a2915f224 100644
--- a/pyomo/core/tests/unit/kernel/test_matrix_constraint.py
+++ b/pyomo/core/tests/unit/kernel/test_matrix_constraint.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/kernel/test_objective.py b/pyomo/core/tests/unit/kernel/test_objective.py
index f60ff9bdb49..810218f1dc2 100644
--- a/pyomo/core/tests/unit/kernel/test_objective.py
+++ b/pyomo/core/tests/unit/kernel/test_objective.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/kernel/test_parameter.py b/pyomo/core/tests/unit/kernel/test_parameter.py
index 04dc08f095f..469ed9fbe8c 100644
--- a/pyomo/core/tests/unit/kernel/test_parameter.py
+++ b/pyomo/core/tests/unit/kernel/test_parameter.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/kernel/test_piecewise.py b/pyomo/core/tests/unit/kernel/test_piecewise.py
index 2c236c0dd12..3d9cf66e39c 100644
--- a/pyomo/core/tests/unit/kernel/test_piecewise.py
+++ b/pyomo/core/tests/unit/kernel/test_piecewise.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/kernel/test_sos.py b/pyomo/core/tests/unit/kernel/test_sos.py
index 9410425d405..b1cb67a96f8 100644
--- a/pyomo/core/tests/unit/kernel/test_sos.py
+++ b/pyomo/core/tests/unit/kernel/test_sos.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/kernel/test_suffix.py b/pyomo/core/tests/unit/kernel/test_suffix.py
index c4c75278d50..2a73888c2d3 100644
--- a/pyomo/core/tests/unit/kernel/test_suffix.py
+++ b/pyomo/core/tests/unit/kernel/test_suffix.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/kernel/test_tuple_container.py b/pyomo/core/tests/unit/kernel/test_tuple_container.py
index 0b45c36b299..c016c5fc789 100644
--- a/pyomo/core/tests/unit/kernel/test_tuple_container.py
+++ b/pyomo/core/tests/unit/kernel/test_tuple_container.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/kernel/test_variable.py b/pyomo/core/tests/unit/kernel/test_variable.py
index e360240f3b2..181eb15c972 100644
--- a/pyomo/core/tests/unit/kernel/test_variable.py
+++ b/pyomo/core/tests/unit/kernel/test_variable.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_action.py b/pyomo/core/tests/unit/test_action.py
index 5db6f165854..3481c90a021 100644
--- a/pyomo/core/tests/unit/test_action.py
+++ b/pyomo/core/tests/unit/test_action.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_block.py b/pyomo/core/tests/unit/test_block.py
index f68850d9421..3d578f7dc88 100644
--- a/pyomo/core/tests/unit/test_block.py
+++ b/pyomo/core/tests/unit/test_block.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -13,6 +13,7 @@
 #
 
 from io import StringIO
+import logging
 import os
 import sys
 import types
@@ -54,7 +55,7 @@
 from pyomo.core.base.block import (
     ScalarBlock,
     SubclassOf,
-    _BlockData,
+    BlockData,
     declare_custom_block,
 )
 import pyomo.core.expr as EXPR
@@ -851,7 +852,7 @@ class DerivedBlock(ScalarBlock):
             _Block_reserved_words = None
 
         DerivedBlock._Block_reserved_words = (
-            set(['a', 'b', 'c']) | _BlockData._Block_reserved_words
+            set(['a', 'b', 'c']) | BlockData._Block_reserved_words
         )
 
         m = ConcreteModel()
@@ -965,7 +966,7 @@ def __init__(self, *args, **kwds):
         b.c.d.e = Block()
         with self.assertRaisesRegex(
             ValueError,
-            r'_BlockData.transfer_attributes_from\(\): '
+            r'BlockData.transfer_attributes_from\(\): '
             r'Cannot set a sub-block \(c.d.e\) to a parent block \(c\):',
         ):
             b.c.d.e.transfer_attributes_from(b.c)
@@ -974,7 +975,7 @@ def __init__(self, *args, **kwds):
         b = Block(concrete=True)
         with self.assertRaisesRegex(
             ValueError,
-            r'_BlockData.transfer_attributes_from\(\): expected a Block '
+            r'BlockData.transfer_attributes_from\(\): expected a Block '
             'or dict; received str',
         ):
             b.transfer_attributes_from('foo')
@@ -2626,19 +2627,16 @@ def test_pprint(self):
         m = HierarchicalModel().model
         buf = StringIO()
         m.pprint(ostream=buf)
-        ref = """3 Set Declarations
+        ref = """2 Set Declarations
     a1_IDX : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    2 : {5, 4}
     a3_IDX : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    2 : {6, 7}
-    a_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    3 : {1, 2, 3}
 
 3 Block Declarations
-    a : Size=3, Index=a_index, Active=True
+    a : Size=3, Index={1, 2, 3}, Active=True
         a[1] : Active=True
             2 Block Declarations
                 c : Size=2, Index=a1_IDX, Active=True
@@ -2668,9 +2666,8 @@ def test_pprint(self):
     c : Size=1, Index=None, Active=True
         0 Declarations: 
 
-6 Declarations: a1_IDX a3_IDX c a_index a b
+5 Declarations: a1_IDX a3_IDX c a b
 """
-        print(buf.getvalue())
         self.assertEqual(ref, buf.getvalue())
 
     @unittest.skipIf(not 'glpk' in solvers, "glpk solver is not available")
@@ -2979,9 +2976,70 @@ def test_write_exceptions(self):
         with self.assertRaisesRegex(ValueError, ".*Cannot write model in format"):
             m.write(format="bogus")
 
-    def test_override_pprint(self):
+    def test_custom_block(self):
+        @declare_custom_block('TestingBlock')
+        class TestingBlockData(BlockData):
+            def __init__(self, component):
+                BlockData.__init__(self, component)
+                logging.getLogger(__name__).warning("TestingBlockData.__init__")
+
+        self.assertIn('TestingBlock', globals())
+        self.assertIn('ScalarTestingBlock', globals())
+        self.assertIn('IndexedTestingBlock', globals())
+        self.assertIs(TestingBlock.__module__, __name__)
+        self.assertIs(ScalarTestingBlock.__module__, __name__)
+        self.assertIs(IndexedTestingBlock.__module__, __name__)
+
+        with LoggingIntercept() as LOG:
+            obj = TestingBlock()
+        self.assertIs(type(obj), ScalarTestingBlock)
+        self.assertEqual(LOG.getvalue().strip(), "TestingBlockData.__init__")
+
+        with LoggingIntercept() as LOG:
+            obj = TestingBlock([1, 2])
+        self.assertIs(type(obj), IndexedTestingBlock)
+        self.assertEqual(LOG.getvalue(), "")
+
+        # Test that we can derive from a ScalarCustomBlock
+        class DerivedScalarTestingBlock(ScalarTestingBlock):
+            pass
+
+        with LoggingIntercept() as LOG:
+            obj = DerivedScalarTestingBlock()
+        self.assertIs(type(obj), DerivedScalarTestingBlock)
+        self.assertEqual(LOG.getvalue().strip(), "TestingBlockData.__init__")
+
+    def test_custom_block_ctypes(self):
+        @declare_custom_block('TestingBlock')
+        class TestingBlockData(BlockData):
+            pass
+
+        self.assertIs(TestingBlock().ctype, Block)
+
+        @declare_custom_block('TestingBlock', True)
+        class TestingBlockData(BlockData):
+            pass
+
+        self.assertIs(TestingBlock().ctype, TestingBlock)
+
+        @declare_custom_block('TestingBlock', Constraint)
+        class TestingBlockData(BlockData):
+            pass
+
+        self.assertIs(TestingBlock().ctype, Constraint)
+
+        with self.assertRaisesRegex(
+            ValueError,
+            r"Expected new_ctype to be either type or 'True'; received: \[\]",
+        ):
+
+            @declare_custom_block('TestingBlock', [])
+            class TestingBlockData(BlockData):
+                pass
+
+    def test_custom_block_override_pprint(self):
         @declare_custom_block('TempBlock')
-        class TempBlockData(_BlockData):
+        class TempBlockData(BlockData):
             def pprint(self, ostream=None, verbose=False, prefix=""):
                 ostream.write('Testing pprint of a custom block.')
 
@@ -3056,9 +3114,9 @@ def test_derived_block_construction(self):
         class ConcreteBlock(Block):
             pass
 
-        class ScalarConcreteBlock(_BlockData, ConcreteBlock):
+        class ScalarConcreteBlock(BlockData, ConcreteBlock):
             def __init__(self, *args, **kwds):
-                _BlockData.__init__(self, component=self)
+                BlockData.__init__(self, component=self)
                 ConcreteBlock.__init__(self, *args, **kwds)
 
         _buf = []
@@ -3407,6 +3465,97 @@ def test_deduplicate_component_data_iterindex(self):
             ],
         )
 
+    def test_private_data(self):
+        m = ConcreteModel()
+        m.b = Block()
+        m.b.b = Block([1, 2])
+
+        mfe = m.private_data()
+        self.assertIsInstance(mfe, dict)
+        self.assertEqual(len(mfe), 0)
+        self.assertEqual(len(m._private_data), 1)
+        self.assertIn('pyomo.core.tests.unit.test_block', m._private_data)
+        self.assertIs(mfe, m._private_data['pyomo.core.tests.unit.test_block'])
+
+        with self.assertRaisesRegex(
+            ValueError,
+            "All keys in the 'private_data' dictionary must "
+            "be substrings of the caller's module name. "
+            "Received 'no mice here' when calling private_data on Block "
+            "'b'.",
+        ):
+            mfe2 = m.b.private_data('no mice here')
+
+        mfe3 = m.b.b[1].private_data('pyomo.core.tests')
+        self.assertIsInstance(mfe3, dict)
+        self.assertEqual(len(mfe3), 0)
+        self.assertIsInstance(m.b.b[1]._private_data, dict)
+        self.assertEqual(len(m.b.b[1]._private_data), 1)
+        self.assertIn('pyomo.core.tests', m.b.b[1]._private_data)
+        self.assertIs(mfe3, m.b.b[1]._private_data['pyomo.core.tests'])
+        mfe3['there are cookies'] = 'but no mice'
+
+        mfe4 = m.b.b[1].private_data('pyomo.core.tests')
+        self.assertIs(mfe4, mfe3)
+
+    def test_register_private_data(self):
+        _save = Block._private_data_initializers
+
+        Block._private_data_initializers = pdi = _save.copy()
+        pdi.clear()
+        try:
+            self.assertEqual(len(pdi), 0)
+            b = Block(concrete=True)
+            ps = b.private_data()
+            self.assertEqual(ps, {})
+            self.assertEqual(len(pdi), 1)
+        finally:
+            Block._private_data_initializers = _save
+
+        def init():
+            return {'a': None, 'b': 1}
+
+        Block._private_data_initializers = pdi = _save.copy()
+        pdi.clear()
+        try:
+            self.assertEqual(len(pdi), 0)
+            Block.register_private_data_initializer(init)
+            self.assertEqual(len(pdi), 1)
+
+            b = Block(concrete=True)
+            ps = b.private_data()
+            self.assertEqual(ps, {'a': None, 'b': 1})
+            self.assertEqual(len(pdi), 1)
+        finally:
+            Block._private_data_initializers = _save
+
+        Block._private_data_initializers = pdi = _save.copy()
+        pdi.clear()
+        try:
+            Block.register_private_data_initializer(init)
+            self.assertEqual(len(pdi), 1)
+            Block.register_private_data_initializer(init, 'pyomo')
+            self.assertEqual(len(pdi), 2)
+
+            with self.assertRaisesRegex(
+                RuntimeError,
+                r"Duplicate initializer registration for 'private_data' "
+                r"dictionary \(scope=pyomo.core.tests.unit.test_block\)",
+            ):
+                Block.register_private_data_initializer(init)
+
+            with self.assertRaisesRegex(
+                ValueError,
+                r"'private_data' scope must be substrings of the caller's "
+                r"module name. Received 'invalid' when calling "
+                r"register_private_data_initializer\(\).",
+            ):
+                Block.register_private_data_initializer(init, 'invalid')
+
+            self.assertEqual(len(pdi), 2)
+        finally:
+            Block._private_data_initializers = _save
+
 
 if __name__ == "__main__":
     unittest.main()
diff --git a/pyomo/core/tests/unit/test_block_model.py b/pyomo/core/tests/unit/test_block_model.py
index ed751e96fc5..b4cf34e7516 100644
--- a/pyomo/core/tests/unit/test_block_model.py
+++ b/pyomo/core/tests/unit/test_block_model.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_bounds.py b/pyomo/core/tests/unit/test_bounds.py
index c2c6a69bdd2..23554f555c9 100644
--- a/pyomo/core/tests/unit/test_bounds.py
+++ b/pyomo/core/tests/unit/test_bounds.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_check.py b/pyomo/core/tests/unit/test_check.py
index 5b2d5408fd5..e61e3998fb7 100644
--- a/pyomo/core/tests/unit/test_check.py
+++ b/pyomo/core/tests/unit/test_check.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_compare.py b/pyomo/core/tests/unit/test_compare.py
index 8b8538a8656..7c3536bc084 100644
--- a/pyomo/core/tests/unit/test_compare.py
+++ b/pyomo/core/tests/unit/test_compare.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -165,17 +165,11 @@ def test_expr_if(self):
             0,
             (EqualityExpression, 2),
             (LinearExpression, 2),
-            (MonomialTermExpression, 2),
-            1,
             m.y,
-            (MonomialTermExpression, 2),
-            1,
             m.x,
             0,
             (EqualityExpression, 2),
             (LinearExpression, 2),
-            (MonomialTermExpression, 2),
-            1,
             m.y,
             (MonomialTermExpression, 2),
             -1,
diff --git a/pyomo/core/tests/unit/test_component.py b/pyomo/core/tests/unit/test_component.py
index b4408fe8c54..b12db9af047 100644
--- a/pyomo/core/tests/unit/test_component.py
+++ b/pyomo/core/tests/unit/test_component.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -66,19 +66,17 @@ def test_getname(self):
         )
 
         m.b[2]._component = None
-        self.assertEqual(
-            m.b[2].getname(fully_qualified=True), "[Unattached _BlockData]"
-        )
+        self.assertEqual(m.b[2].getname(fully_qualified=True), "[Unattached BlockData]")
         # I think that getname() should do this:
         # self.assertEqual(m.b[2].c[2,4].getname(fully_qualified=True),
-        #                 "[Unattached _BlockData].c[2,4]")
+        #                 "[Unattached BlockData].c[2,4]")
         # but it doesn't match current behavior.  I will file a PEP to
         # propose changing the behavior later and proceed to test
         # current behavior.
         self.assertEqual(m.b[2].c[2, 4].getname(fully_qualified=True), "c[2,4]")
 
         self.assertEqual(
-            m.b[2].getname(fully_qualified=False), "[Unattached _BlockData]"
+            m.b[2].getname(fully_qualified=False), "[Unattached BlockData]"
         )
         self.assertEqual(m.b[2].c[2, 4].getname(fully_qualified=False), "c[2,4]")
 
diff --git a/pyomo/core/tests/unit/test_componentuid.py b/pyomo/core/tests/unit/test_componentuid.py
index 1c9b3c444bf..5808bedb7fd 100644
--- a/pyomo/core/tests/unit/test_componentuid.py
+++ b/pyomo/core/tests/unit/test_componentuid.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -601,31 +601,26 @@ def test_generate_cuid_string_map(self):
             ComponentUID.generate_cuid_string_map(model, repr_version=1),
             ComponentUID.generate_cuid_string_map(model),
         )
-        self.assertEqual(len(cuids[0]), 29)
-        self.assertEqual(len(cuids[1]), 29)
+        self.assertEqual(len(cuids[0]), 24)
+        self.assertEqual(len(cuids[1]), 24)
         for obj in [
             model,
             model.x,
             model.y,
-            model.y_index,
             model.y[1],
             model.y[2],
             model.V,
-            model.V_index,
             model.V['a', 'b'],
             model.V[1, '2'],
             model.V[3, 4],
             model.b,
             model.b.z,
-            model.b.z_index,
             model.b.z[1],
             model.b.z['2'],
             getattr(model.b, '.H'),
-            getattr(model.b, '.H_index'),
             getattr(model.b, '.H')['a'],
             getattr(model.b, '.H')[2],
             model.B,
-            model.B_index,
             model.B['a'],
             getattr(model.B['a'], '.k'),
             model.B[2],
@@ -642,23 +637,20 @@ def test_generate_cuid_string_map(self):
             ),
             ComponentUID.generate_cuid_string_map(model, descend_into=False),
         )
-        self.assertEqual(len(cuids[0]), 18)
-        self.assertEqual(len(cuids[1]), 18)
+        self.assertEqual(len(cuids[0]), 15)
+        self.assertEqual(len(cuids[1]), 15)
         for obj in [
             model,
             model.x,
             model.y,
-            model.y_index,
             model.y[1],
             model.y[2],
             model.V,
-            model.V_index,
             model.V['a', 'b'],
             model.V[1, '2'],
             model.V[3, 4],
             model.b,
             model.B,
-            model.B_index,
             model.B['a'],
             model.B[2],
             model.component('c tuple')[(1,)],
diff --git a/pyomo/core/tests/unit/test_con.py b/pyomo/core/tests/unit/test_con.py
index bd90972fee2..15f190e281e 100644
--- a/pyomo/core/tests/unit/test_con.py
+++ b/pyomo/core/tests/unit/test_con.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -44,7 +44,7 @@
     InequalityExpression,
     RangedExpression,
 )
-from pyomo.core.base.constraint import _GeneralConstraintData
+from pyomo.core.base.constraint import ConstraintData
 
 
 class TestConstraintCreation(unittest.TestCase):
@@ -1074,7 +1074,7 @@ def test_setitem(self):
         m.c[2] = m.x**2 <= 4
         self.assertEqual(len(m.c), 1)
         self.assertEqual(list(m.c.keys()), [2])
-        self.assertIsInstance(m.c[2], _GeneralConstraintData)
+        self.assertIsInstance(m.c[2], ConstraintData)
         self.assertEqual(m.c[2].upper, 4)
 
         m.c[3] = Constraint.Skip
@@ -1388,7 +1388,7 @@ def test_empty_singleton(self):
         # Even though we construct a ScalarConstraint,
         # if it is not initialized that means it is "empty"
         # and we should encounter errors when trying to access the
-        # _ConstraintData interface methods until we assign
+        # ConstraintData interface methods until we assign
         # something to the constraint.
         #
         self.assertEqual(a._constructed, True)
diff --git a/pyomo/core/tests/unit/test_concrete.py b/pyomo/core/tests/unit/test_concrete.py
index a9bd75f05c7..9083c5cf7f9 100644
--- a/pyomo/core/tests/unit/test_concrete.py
+++ b/pyomo/core/tests/unit/test_concrete.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_connector.py b/pyomo/core/tests/unit/test_connector.py
index 1dde9f3af24..3871f5f372a 100644
--- a/pyomo/core/tests/unit/test_connector.py
+++ b/pyomo/core/tests/unit/test_connector.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -301,7 +301,7 @@ def test_expand_single_scalar(self):
         m.component('c.expanded').pprint(ostream=os)
         self.assertEqual(
             os.getvalue(),
-            """c.expanded : Size=1, Index='c.expanded_index', Active=True
+            """c.expanded : Size=1, Index={1}, Active=True
     Key : Lower : Body : Upper : Active
       1 :   1.0 :    x :   1.0 :   True
 """,
@@ -336,7 +336,7 @@ def test_expand_scalar(self):
         m.component('c.expanded').pprint(ostream=os)
         self.assertEqual(
             os.getvalue(),
-            """c.expanded : Size=2, Index='c.expanded_index', Active=True
+            """c.expanded : Size=2, Index={1, 2}, Active=True
     Key : Lower : Body : Upper : Active
       1 :   1.0 :    x :   1.0 :   True
       2 :   1.0 :    y :   1.0 :   True
@@ -372,7 +372,7 @@ def test_expand_expression(self):
         m.component('c.expanded').pprint(ostream=os)
         self.assertEqual(
             os.getvalue(),
-            """c.expanded : Size=2, Index='c.expanded_index', Active=True
+            """c.expanded : Size=2, Index={1, 2}, Active=True
     Key : Lower : Body  : Upper : Active
       1 :   1.0 :   - x :   1.0 :   True
       2 :   1.0 : 1 + y :   1.0 :   True
@@ -408,7 +408,7 @@ def test_expand_indexed(self):
         m.component('c.expanded').pprint(ostream=os)
         self.assertEqual(
             os.getvalue(),
-            """c.expanded : Size=3, Index='c.expanded_index', Active=True
+            """c.expanded : Size=3, Index={1, 2, 3}, Active=True
     Key : Lower : Body : Upper : Active
       1 :   1.0 : x[1] :   1.0 :   True
       2 :   1.0 : x[2] :   1.0 :   True
@@ -451,7 +451,7 @@ def test_expand_empty_scalar(self):
         m.component('c.expanded').pprint(ostream=os)
         self.assertEqual(
             os.getvalue(),
-            """c.expanded : Size=2, Index='c.expanded_index', Active=True
+            """c.expanded : Size=2, Index={1, 2}, Active=True
     Key : Lower : Body              : Upper : Active
       1 :   0.0 : x - 'ECON.auto.x' :   0.0 :   True
       2 :   0.0 : y - 'ECON.auto.y' :   0.0 :   True
@@ -488,7 +488,7 @@ def test_expand_empty_expression(self):
         m.component('c.expanded').pprint(ostream=os)
         self.assertEqual(
             os.getvalue(),
-            """c.expanded : Size=2, Index='c.expanded_index', Active=True
+            """c.expanded : Size=2, Index={1, 2}, Active=True
     Key : Lower : Body                  : Upper : Active
       1 :   0.0 :   - x - 'ECON.auto.x' :   0.0 :   True
       2 :   0.0 : 1 + y - 'ECON.auto.y' :   0.0 :   True
@@ -533,7 +533,7 @@ def test_expand_empty_indexed(self):
         m.component('c.expanded').pprint(ostream=os)
         self.assertEqual(
             os.getvalue(),
-            """c.expanded : Size=3, Index='c.expanded_index', Active=True
+            """c.expanded : Size=3, Index={1, 2, 3}, Active=True
     Key : Lower : Body                    : Upper : Active
       1 :   0.0 : x[1] - 'ECON.auto.x'[1] :   0.0 :   True
       2 :   0.0 : x[2] - 'ECON.auto.x'[2] :   0.0 :   True
@@ -590,7 +590,7 @@ def test_expand_multiple_empty_indexed(self):
         m.component('c.expanded').pprint(ostream=os)
         self.assertEqual(
             os.getvalue(),
-            """c.expanded : Size=3, Index='c.expanded_index', Active=True
+            """c.expanded : Size=3, Index={1, 2, 3}, Active=True
     Key : Lower : Body                     : Upper : Active
       1 :   0.0 : x[1] - 'ECON1.auto.x'[1] :   0.0 :   True
       2 :   0.0 : x[2] - 'ECON1.auto.x'[2] :   0.0 :   True
@@ -602,7 +602,7 @@ def test_expand_multiple_empty_indexed(self):
         m.component('d.expanded').pprint(ostream=os)
         self.assertEqual(
             os.getvalue(),
-            """d.expanded : Size=3, Index='d.expanded_index', Active=True
+            """d.expanded : Size=3, Index={1, 2, 3}, Active=True
     Key : Lower : Body                                  : Upper : Active
       1 :   0.0 : 'ECON2.auto.x'[1] - 'ECON1.auto.x'[1] :   0.0 :   True
       2 :   0.0 : 'ECON2.auto.x'[2] - 'ECON1.auto.x'[2] :   0.0 :   True
@@ -653,7 +653,7 @@ def test_expand_multiple_indexed(self):
         m.component('c.expanded').pprint(ostream=os)
         self.assertEqual(
             os.getvalue(),
-            """c.expanded : Size=3, Index='c.expanded_index', Active=True
+            """c.expanded : Size=3, Index={1, 2, 3}, Active=True
     Key : Lower : Body         : Upper : Active
       1 :   0.0 : x[1] - a2[1] :   0.0 :   True
       2 :   0.0 : x[2] - a2[2] :   0.0 :   True
@@ -665,7 +665,7 @@ def test_expand_multiple_indexed(self):
         m.component('d.expanded').pprint(ostream=os)
         self.assertEqual(
             os.getvalue(),
-            """d.expanded : Size=3, Index='d.expanded_index', Active=True
+            """d.expanded : Size=3, Index={1, 2, 3}, Active=True
     Key : Lower : Body          : Upper : Active
       1 :   0.0 : a1[1] - a2[1] :   0.0 :   True
       2 :   0.0 : a1[2] - a2[2] :   0.0 :   True
@@ -734,7 +734,7 @@ def test_expand_implicit_indexed(self):
         m.component('c.expanded').pprint(ostream=os)
         self.assertEqual(
             os.getvalue(),
-            """c.expanded : Size=3, Index='c.expanded_index', Active=True
+            """c.expanded : Size=3, Index={1, 2, 3}, Active=True
     Key : Lower : Body               : Upper : Active
       1 :   0.0 :       x[1] - a2[1] :   0.0 :   True
       2 :   0.0 :       x[2] - a2[2] :   0.0 :   True
@@ -746,7 +746,7 @@ def test_expand_implicit_indexed(self):
         m.component('d.expanded').pprint(ostream=os)
         self.assertEqual(
             os.getvalue(),
-            """d.expanded : Size=3, Index='d.expanded_index', Active=True
+            """d.expanded : Size=3, Index={1, 2, 3}, Active=True
     Key : Lower : Body                     : Upper : Active
       1 :   0.0 : 'ECON2.auto.x'[1] - x[1] :   0.0 :   True
       2 :   0.0 : 'ECON2.auto.x'[2] - x[2] :   0.0 :   True
@@ -789,7 +789,7 @@ def test_varlist_aggregator(self):
         m.component('c.expanded').pprint(ostream=os)
         self.assertEqual(
             os.getvalue(),
-            """c.expanded : Size=2, Index='c.expanded_index', Active=True
+            """c.expanded : Size=2, Index={1, 2}, Active=True
     Key : Lower : Body                        : Upper : Active
       1 :   0.0 : flow[1] - 'ECON1.auto.flow' :   0.0 :   True
       2 :   0.0 :  phase - 'ECON1.auto.phase' :   0.0 :   True
@@ -800,7 +800,7 @@ def test_varlist_aggregator(self):
         m.component('d.expanded').pprint(ostream=os)
         self.assertEqual(
             os.getvalue(),
-            """d.expanded : Size=2, Index='d.expanded_index', Active=True
+            """d.expanded : Size=2, Index={1, 2}, Active=True
     Key : Lower : Body                        : Upper : Active
       1 :   0.0 : 'ECON2.auto.flow' - flow[2] :   0.0 :   True
       2 :   0.0 :  'ECON2.auto.phase' - phase :   0.0 :   True
@@ -844,7 +844,7 @@ def test_indexed_connector(self):
         m.component('eq.expanded').pprint(ostream=os)
         self.assertEqual(
             os.getvalue(),
-            """eq.expanded : Size=1, Index='eq.expanded_index', Active=True
+            """eq.expanded : Size=1, Index={1}, Active=True
     Key : Lower : Body  : Upper : Active
       1 :   0.0 : x - y :   0.0 :   True
 """,
diff --git a/pyomo/core/tests/unit/test_deprecation.py b/pyomo/core/tests/unit/test_deprecation.py
index 9adf2de26cd..7d718a4bd2a 100644
--- a/pyomo/core/tests/unit/test_deprecation.py
+++ b/pyomo/core/tests/unit/test_deprecation.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_derivs.py b/pyomo/core/tests/unit/test_derivs.py
index 7db284cb29a..6a4fc6814b3 100644
--- a/pyomo/core/tests/unit/test_derivs.py
+++ b/pyomo/core/tests/unit/test_derivs.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_dict_objects.py b/pyomo/core/tests/unit/test_dict_objects.py
index 7d3244f4d86..ef9f330bfff 100644
--- a/pyomo/core/tests/unit/test_dict_objects.py
+++ b/pyomo/core/tests/unit/test_dict_objects.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -17,10 +17,10 @@
     ObjectiveDict,
     ExpressionDict,
 )
-from pyomo.core.base.var import _GeneralVarData
-from pyomo.core.base.constraint import _GeneralConstraintData
-from pyomo.core.base.objective import _GeneralObjectiveData
-from pyomo.core.base.expression import _GeneralExpressionData
+from pyomo.core.base.var import VarData
+from pyomo.core.base.constraint import ConstraintData
+from pyomo.core.base.objective import ObjectiveData
+from pyomo.core.base.expression import ExpressionData
 
 
 class _TestComponentDictBase(object):
@@ -348,10 +348,10 @@ def test_active(self):
 
 
 class TestVarDict(_TestComponentDictBase, unittest.TestCase):
-    # Note: the updated _GeneralVarData class only takes an optional
+    # Note: the updated VarData class only takes an optional
     # parent argument (you no longer pass the domain in)
     _ctype = VarDict
-    _cdatatype = lambda self, arg: _GeneralVarData()
+    _cdatatype = lambda self, arg: VarData()
 
     def setUp(self):
         _TestComponentDictBase.setUp(self)
@@ -360,7 +360,7 @@ def setUp(self):
 
 class TestExpressionDict(_TestComponentDictBase, unittest.TestCase):
     _ctype = ExpressionDict
-    _cdatatype = _GeneralExpressionData
+    _cdatatype = ExpressionData
 
     def setUp(self):
         _TestComponentDictBase.setUp(self)
@@ -375,7 +375,7 @@ def setUp(self):
 
 class TestConstraintDict(_TestActiveComponentDictBase, unittest.TestCase):
     _ctype = ConstraintDict
-    _cdatatype = _GeneralConstraintData
+    _cdatatype = ConstraintData
 
     def setUp(self):
         _TestComponentDictBase.setUp(self)
@@ -384,7 +384,7 @@ def setUp(self):
 
 class TestObjectiveDict(_TestActiveComponentDictBase, unittest.TestCase):
     _ctype = ObjectiveDict
-    _cdatatype = _GeneralObjectiveData
+    _cdatatype = ObjectiveData
 
     def setUp(self):
         _TestComponentDictBase.setUp(self)
diff --git a/pyomo/core/tests/unit/test_disable_methods.py b/pyomo/core/tests/unit/test_disable_methods.py
index 4d6595e5fe8..618752aee85 100644
--- a/pyomo/core/tests/unit/test_disable_methods.py
+++ b/pyomo/core/tests/unit/test_disable_methods.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_enums.py b/pyomo/core/tests/unit/test_enums.py
index 8f342e55188..cce908a87de 100644
--- a/pyomo/core/tests/unit/test_enums.py
+++ b/pyomo/core/tests/unit/test_enums.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_expr5.txt b/pyomo/core/tests/unit/test_expr5.txt
index a5fc934bd77..2bf78cb4985 100644
--- a/pyomo/core/tests/unit/test_expr5.txt
+++ b/pyomo/core/tests/unit/test_expr5.txt
@@ -1,11 +1,8 @@
-2 Set Declarations
+1 Set Declarations
     A : set A
         Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    3 : {1, 2, 3}
-    c3_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    1 :    {1,}
 
 2 Param Declarations
     B : param B
@@ -49,8 +46,8 @@
           2 :  -Inf : B[2]*x[2] :   1.0 :   True
           3 :  -Inf : B[3]*x[3] :   1.0 :   True
     c3 : con c3
-        Size=1, Index=c3_index, Active=True
+        Size=1, Index={1}, Active=True
         Key : Lower : Body : Upper : Active
           1 :  -Inf :    y :   0.0 :   True
 
-10 Declarations: A B C x y o c1 c2 c3_index c3
+9 Declarations: A B C x y o c1 c2 c3
diff --git a/pyomo/core/tests/unit/test_expr_misc.py b/pyomo/core/tests/unit/test_expr_misc.py
index 4ec53521d6b..f4fd7556117 100644
--- a/pyomo/core/tests/unit/test_expr_misc.py
+++ b/pyomo/core/tests/unit/test_expr_misc.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_expression.py b/pyomo/core/tests/unit/test_expression.py
index 8dca0062dd0..eb16f7c6142 100644
--- a/pyomo/core/tests/unit/test_expression.py
+++ b/pyomo/core/tests/unit/test_expression.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -29,7 +29,7 @@
     value,
     sum_product,
 )
-from pyomo.core.base.expression import _GeneralExpressionData
+from pyomo.core.base.expression import ExpressionData
 from pyomo.core.expr.compare import compare_expressions, assertExpressionsEqual
 from pyomo.common.tee import capture_output
 
@@ -515,10 +515,10 @@ def test_implicit_definition(self):
         model.E = Expression(model.idx)
         self.assertEqual(len(model.E), 3)
         expr = model.E[1]
-        self.assertIs(type(expr), _GeneralExpressionData)
+        self.assertIs(type(expr), ExpressionData)
         model.E[1] = None
         self.assertIs(expr, model.E[1])
-        self.assertIs(type(expr), _GeneralExpressionData)
+        self.assertIs(type(expr), ExpressionData)
         self.assertIs(expr.expr, None)
         model.E[1] = 5
         self.assertIs(expr, model.E[1])
@@ -537,7 +537,7 @@ def test_explicit_skip_definition(self):
 
         model.E[1] = None
         expr = model.E[1]
-        self.assertIs(type(expr), _GeneralExpressionData)
+        self.assertIs(type(expr), ExpressionData)
         self.assertIs(expr.expr, None)
         model.E[1] = 5
         self.assertIs(expr, model.E[1])
@@ -738,11 +738,11 @@ def test_pprint_oldStyle(self):
         expr = model.e * model.x**2 + model.E[1]
 
         output = """\
-sum(prod(e{sum(mon(1, x), 2)}, pow(x, 2)), E[1]{sum(pow(x, 2), 1)})
+sum(prod(e{sum(x, 2)}, pow(x, 2)), E[1]{sum(pow(x, 2), 1)})
 e : Size=1, Index=None
     Key  : Expression
-    None : sum(mon(1, x), 2)
-E : Size=2, Index=E_index
+    None : sum(x, 2)
+E : Size=2, Index={1, 2}
     Key : Expression
       1 : sum(pow(x, 2), 1)
       2 : sum(pow(x, 2), 1)
@@ -761,7 +761,7 @@ def test_pprint_oldStyle(self):
 e : Size=1, Index=None
     Key  : Expression
     None :        1.0
-E : Size=2, Index=E_index
+E : Size=2, Index={1, 2}
     Key : Expression
       1 : 2.0
       2 : sum(pow(x, 2), 1)
@@ -780,7 +780,7 @@ def test_pprint_oldStyle(self):
 e : Size=1, Index=None
     Key  : Expression
     None :  Undefined
-E : Size=2, Index=E_index
+E : Size=2, Index={1, 2}
     Key : Expression
       1 : Undefined
       2 : sum(pow(x, 2), 1)
@@ -806,7 +806,7 @@ def test_pprint_newStyle(self):
 e : Size=1, Index=None
     Key  : Expression
     None : x + 2
-E : Size=2, Index=E_index
+E : Size=2, Index={1, 2}
     Key : Expression
       1 : x**2 + 1
       2 : x**2 + 1
@@ -830,7 +830,7 @@ def test_pprint_newStyle(self):
 e : Size=1, Index=None
     Key  : Expression
     None :        1.0
-E : Size=2, Index=E_index
+E : Size=2, Index={1, 2}
     Key : Expression
       1 : 2.0
       2 : x**2 + 1
@@ -849,7 +849,7 @@ def test_pprint_newStyle(self):
 e : Size=1, Index=None
     Key  : Expression
     None :  Undefined
-E : Size=2, Index=E_index
+E : Size=2, Index={1, 2}
     Key : Expression
       1 : Undefined
       2 : x**2 + 1
@@ -951,12 +951,7 @@ def test_isub(self):
         assertExpressionsEqual(
             self,
             m.e.expr,
-            EXPR.LinearExpression(
-                [
-                    EXPR.MonomialTermExpression((1, m.x)),
-                    EXPR.MonomialTermExpression((-1, m.y)),
-                ]
-            ),
+            EXPR.LinearExpression([m.x, EXPR.MonomialTermExpression((-1, m.y))]),
         )
         self.assertTrue(compare_expressions(m.e.expr, m.x - m.y))
 
diff --git a/pyomo/core/tests/unit/test_external.py b/pyomo/core/tests/unit/test_external.py
index 96c05b6b0b8..1d4a59647c1 100644
--- a/pyomo/core/tests/unit/test_external.py
+++ b/pyomo/core/tests/unit/test_external.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_indexed.py b/pyomo/core/tests/unit/test_indexed.py
index 29bf22ceeb1..3480b653ea5 100644
--- a/pyomo/core/tests/unit/test_indexed.py
+++ b/pyomo/core/tests/unit/test_indexed.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_indexed_slice.py b/pyomo/core/tests/unit/test_indexed_slice.py
index e89c48a6061..40aaad9fec9 100644
--- a/pyomo/core/tests/unit/test_indexed_slice.py
+++ b/pyomo/core/tests/unit/test_indexed_slice.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -17,7 +17,7 @@
 import pyomo.common.unittest as unittest
 
 from pyomo.environ import Var, Block, ConcreteModel, RangeSet, Set, Any
-from pyomo.core.base.block import _BlockData
+from pyomo.core.base.block import BlockData
 from pyomo.core.base.indexed_component_slice import IndexedComponent_slice
 from pyomo.core.base.set import normalize_index
 
@@ -64,7 +64,7 @@ def tearDown(self):
         self.m = None
 
     def test_simple_getitem(self):
-        self.assertIsInstance(self.m.b[1, 4], _BlockData)
+        self.assertIsInstance(self.m.b[1, 4], BlockData)
 
     def test_simple_getslice(self):
         _slicer = self.m.b[:, 4]
diff --git a/pyomo/core/tests/unit/test_initializer.py b/pyomo/core/tests/unit/test_initializer.py
index b334a6b857b..c0f9ddc9565 100644
--- a/pyomo/core/tests/unit/test_initializer.py
+++ b/pyomo/core/tests/unit/test_initializer.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_kernel_register_numpy_types.py b/pyomo/core/tests/unit/test_kernel_register_numpy_types.py
index 117de5c5f4c..8186c3d6028 100644
--- a/pyomo/core/tests/unit/test_kernel_register_numpy_types.py
+++ b/pyomo/core/tests/unit/test_kernel_register_numpy_types.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -16,7 +16,10 @@
 # Boolean
 numpy_bool_names = []
 if numpy_available:
-    numpy_bool_names.append('bool_')
+    if numpy.__version__[0] == '2':
+        numpy_bool_names.append('bool')
+    else:
+        numpy_bool_names.append('bool_')
 # Integers
 numpy_int_names = []
 if numpy_available:
@@ -34,7 +37,8 @@
 # Reals
 numpy_float_names = []
 if numpy_available:
-    numpy_float_names.append('float_')
+    if hasattr(numpy, 'float_'):
+        numpy_float_names.append('float_')
     numpy_float_names.append('float16')
     numpy_float_names.append('float32')
     numpy_float_names.append('float64')
@@ -46,7 +50,8 @@
 # Complex
 numpy_complex_names = []
 if numpy_available:
-    numpy_complex_names.append('complex_')
+    if hasattr(numpy, 'complex_'):
+        numpy_complex_names.append('complex_')
     numpy_complex_names.append('complex64')
     numpy_complex_names.append('complex128')
     if hasattr(numpy, 'complex192'):
diff --git a/pyomo/core/tests/unit/test_labelers.py b/pyomo/core/tests/unit/test_labelers.py
index 15c56b5390d..579abfd8b52 100644
--- a/pyomo/core/tests/unit/test_labelers.py
+++ b/pyomo/core/tests/unit/test_labelers.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_list_objects.py b/pyomo/core/tests/unit/test_list_objects.py
index 442fa97b6d1..671a8429e06 100644
--- a/pyomo/core/tests/unit/test_list_objects.py
+++ b/pyomo/core/tests/unit/test_list_objects.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -17,10 +17,10 @@
     XObjectiveList,
     XExpressionList,
 )
-from pyomo.core.base.var import _GeneralVarData
-from pyomo.core.base.constraint import _GeneralConstraintData
-from pyomo.core.base.objective import _GeneralObjectiveData
-from pyomo.core.base.expression import _GeneralExpressionData
+from pyomo.core.base.var import VarData
+from pyomo.core.base.constraint import ConstraintData
+from pyomo.core.base.objective import ObjectiveData
+from pyomo.core.base.expression import ExpressionData
 
 
 class _TestComponentListBase(object):
@@ -365,10 +365,10 @@ def test_active(self):
 
 
 class TestVarList(_TestComponentListBase, unittest.TestCase):
-    # Note: the updated _GeneralVarData class only takes an optional
+    # Note: the updated VarData class only takes an optional
     # parent argument (you no longer pass the domain in)
     _ctype = XVarList
-    _cdatatype = lambda self, arg: _GeneralVarData()
+    _cdatatype = lambda self, arg: VarData()
 
     def setUp(self):
         _TestComponentListBase.setUp(self)
@@ -377,7 +377,7 @@ def setUp(self):
 
 class TestExpressionList(_TestComponentListBase, unittest.TestCase):
     _ctype = XExpressionList
-    _cdatatype = _GeneralExpressionData
+    _cdatatype = ExpressionData
 
     def setUp(self):
         _TestComponentListBase.setUp(self)
@@ -392,7 +392,7 @@ def setUp(self):
 
 class TestConstraintList(_TestActiveComponentListBase, unittest.TestCase):
     _ctype = XConstraintList
-    _cdatatype = _GeneralConstraintData
+    _cdatatype = ConstraintData
 
     def setUp(self):
         _TestComponentListBase.setUp(self)
@@ -401,7 +401,7 @@ def setUp(self):
 
 class TestObjectiveList(_TestActiveComponentListBase, unittest.TestCase):
     _ctype = XObjectiveList
-    _cdatatype = _GeneralObjectiveData
+    _cdatatype = ObjectiveData
 
     def setUp(self):
         _TestComponentListBase.setUp(self)
diff --git a/pyomo/core/tests/unit/test_logical_constraint.py b/pyomo/core/tests/unit/test_logical_constraint.py
index ed8120da935..b1f37996018 100644
--- a/pyomo/core/tests/unit/test_logical_constraint.py
+++ b/pyomo/core/tests/unit/test_logical_constraint.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.common.unittest as unittest
 
 from pyomo.core.expr.sympy_tools import sympy_available
diff --git a/pyomo/core/tests/unit/test_logical_expr_expanded.py b/pyomo/core/tests/unit/test_logical_expr_expanded.py
index 95ae0494a48..6468a21e336 100644
--- a/pyomo/core/tests/unit/test_logical_expr_expanded.py
+++ b/pyomo/core/tests/unit/test_logical_expr_expanded.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -15,7 +15,7 @@
 """
 
 import operator
-from itertools import product
+from itertools import permutations, product
 
 import pyomo.common.unittest as unittest
 
@@ -23,6 +23,8 @@
 from pyomo.core.expr.sympy_tools import sympy_available
 from pyomo.core.expr.visitor import identify_variables
 from pyomo.environ import (
+    all_different,
+    count_if,
     land,
     atleast,
     atmost,
@@ -39,6 +41,8 @@
     BooleanVar,
     lnot,
     xor,
+    Var,
+    Integers,
 )
 
 
@@ -234,12 +238,50 @@ def test_nary_atleast(self):
                 )
                 self.assertEqual(value(atleast(ntrue, m.Y)), correct_value)
 
+    def test_nary_all_diff(self):
+        m = ConcreteModel()
+        m.x = Var(range(4), domain=Integers, bounds=(0, 3))
+        for vals in permutations(range(4)):
+            self.assertTrue(value(all_different(*vals)))
+            for i, v in enumerate(vals):
+                m.x[i] = v
+            self.assertTrue(value(all_different(m.x)))
+        self.assertFalse(value(all_different(1, 1, 2, 3)))
+        m.x[0] = 1
+        m.x[1] = 1
+        m.x[2] = 2
+        m.x[3] = 3
+        self.assertFalse(value(all_different(m.x)))
+
+    def test_count_if(self):
+        nargs = 3
+        m = ConcreteModel()
+        m.s = RangeSet(nargs)
+        m.Y = BooleanVar(m.s)
+        m.x = Var(domain=Integers, bounds=(0, 3))
+        for truth_combination in _generate_possible_truth_inputs(nargs):
+            for ntrue in range(nargs + 1):
+                m.Y.set_values(dict(enumerate(truth_combination, 1)))
+                correct_value = sum(truth_combination)
+                self.assertEqual(value(count_if(*(m.Y[i] for i in m.s))), correct_value)
+                self.assertEqual(value(count_if(m.Y)), correct_value)
+        m.x = 2
+        self.assertEqual(
+            value(count_if([m.Y[i] for i in m.s] + [m.x == 3])), correct_value
+        )
+        m.x = 3
+        self.assertEqual(
+            value(count_if([m.Y[i] for i in m.s] + [m.x == 3])), correct_value + 1
+        )
+
     def test_to_string(self):
         m = ConcreteModel()
         m.Y1 = BooleanVar()
         m.Y2 = BooleanVar()
         m.Y3 = BooleanVar()
         m.Y4 = BooleanVar()
+        m.int1 = Var(domain=Integers)
+        m.int2 = Var(domain=Integers)
 
         self.assertEqual(str(land(m.Y1, m.Y2, m.Y3)), "Y1 ∧ Y2 ∧ Y3")
         self.assertEqual(str(lor(m.Y1, m.Y2, m.Y3)), "Y1 ∨ Y2 ∨ Y3")
@@ -249,6 +291,10 @@ def test_to_string(self):
         self.assertEqual(str(atleast(1, m.Y1, m.Y2)), "atleast(1: [Y1, Y2])")
         self.assertEqual(str(atmost(1, m.Y1, m.Y2)), "atmost(1: [Y1, Y2])")
         self.assertEqual(str(exactly(1, m.Y1, m.Y2)), "exactly(1: [Y1, Y2])")
+        self.assertEqual(
+            str(all_different(m.int1, m.int2)), "all_different(int1, int2)"
+        )
+        self.assertEqual(str(count_if(m.Y1, m.Y2)), "count_if(Y1, Y2)")
 
         # Precedence checks
         self.assertEqual(str(m.Y1.implies(m.Y2).lor(m.Y3)), "(Y1 --> Y2) ∨ Y3")
@@ -266,11 +312,16 @@ def test_node_types(self):
         m.Y1 = BooleanVar()
         m.Y2 = BooleanVar()
         m.Y3 = BooleanVar()
+        m.int1 = Var(domain=Integers)
+        m.int2 = Var(domain=Integers)
+        m.int3 = Var(domain=Integers)
 
         self.assertFalse(m.Y1.is_expression_type())
         self.assertTrue(lnot(m.Y1).is_expression_type())
         self.assertTrue(equivalent(m.Y1, m.Y2).is_expression_type())
         self.assertTrue(atmost(1, [m.Y1, m.Y2, m.Y3]).is_expression_type())
+        self.assertTrue(all_different(m.int1, m.int2, m.int3).is_expression_type())
+        self.assertTrue(count_if(m.Y1, m.Y2, m.Y3).is_expression_type())
 
     def test_numeric_invalid(self):
         m = ConcreteModel()
diff --git a/pyomo/core/tests/unit/test_logical_to_linear.py b/pyomo/core/tests/unit/test_logical_to_linear.py
index 22133f22ba2..e777259f8ce 100644
--- a/pyomo/core/tests/unit/test_logical_to_linear.py
+++ b/pyomo/core/tests/unit/test_logical_to_linear.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_matrix_constraint.py b/pyomo/core/tests/unit/test_matrix_constraint.py
index d9b51de7bf6..993e2a18eb3 100644
--- a/pyomo/core/tests/unit/test_matrix_constraint.py
+++ b/pyomo/core/tests/unit/test_matrix_constraint.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_misc.py b/pyomo/core/tests/unit/test_misc.py
index 261c94d96bd..440c8807358 100644
--- a/pyomo/core/tests/unit/test_misc.py
+++ b/pyomo/core/tests/unit/test_misc.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_model.py b/pyomo/core/tests/unit/test_model.py
index 95ad17e97f4..9016f9937c0 100644
--- a/pyomo/core/tests/unit/test_model.py
+++ b/pyomo/core/tests/unit/test_model.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_mutable.py b/pyomo/core/tests/unit/test_mutable.py
index 933ef1fe3dc..d10622d84c0 100644
--- a/pyomo/core/tests/unit/test_mutable.py
+++ b/pyomo/core/tests/unit/test_mutable.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_numeric_expr.py b/pyomo/core/tests/unit/test_numeric_expr.py
index a4f3295441e..efb01e6d6ce 100644
--- a/pyomo/core/tests/unit/test_numeric_expr.py
+++ b/pyomo/core/tests/unit/test_numeric_expr.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -112,7 +112,7 @@
 from pyomo.core.base.label import NumericLabeler
 from pyomo.core.expr.template_expr import IndexTemplate
 from pyomo.core.expr import expr_common
-from pyomo.core.base.var import _GeneralVarData
+from pyomo.core.base.var import VarData
 
 from pyomo.repn import generate_standard_repn
 from pyomo.core.expr.numvalue import NumericValue
@@ -294,7 +294,7 @@ def value_check(self, exp, val):
 
 class TestExpression_EvaluateVarData(TestExpression_EvaluateNumericValue):
     def create(self, val, domain):
-        tmp = _GeneralVarData()
+        tmp = VarData()
         tmp.domain = domain
         tmp.value = val
         return tmp
@@ -638,12 +638,7 @@ def test_simpleSum(self):
         m.b = Var()
         e = m.a + m.b
         #
-        self.assertExpressionsEqual(
-            e,
-            LinearExpression(
-                [MonomialTermExpression((1, m.a)), MonomialTermExpression((1, m.b))]
-            ),
-        )
+        self.assertExpressionsEqual(e, LinearExpression([m.a, m.b]))
 
         self.assertRaises(KeyError, e.arg, 3)
 
@@ -654,14 +649,7 @@ def test_simpleSum_API(self):
         e = m.a + m.b
         e += 2 * m.a
         self.assertExpressionsEqual(
-            e,
-            LinearExpression(
-                [
-                    MonomialTermExpression((1, m.a)),
-                    MonomialTermExpression((1, m.b)),
-                    MonomialTermExpression((2, m.a)),
-                ]
-            ),
+            e, LinearExpression([m.a, m.b, MonomialTermExpression((2, m.a))])
         )
 
     def test_constSum(self):
@@ -669,13 +657,9 @@ def test_constSum(self):
         m = AbstractModel()
         m.a = Var()
         #
-        self.assertExpressionsEqual(
-            m.a + 5, LinearExpression([MonomialTermExpression((1, m.a)), 5])
-        )
+        self.assertExpressionsEqual(m.a + 5, LinearExpression([m.a, 5]))
 
-        self.assertExpressionsEqual(
-            5 + m.a, LinearExpression([5, MonomialTermExpression((1, m.a))])
-        )
+        self.assertExpressionsEqual(5 + m.a, LinearExpression([5, m.a]))
 
     def test_nestedSum(self):
         #
@@ -696,12 +680,7 @@ def test_nestedSum(self):
         #       a   b
         e1 = m.a + m.b
         e = e1 + 5
-        self.assertExpressionsEqual(
-            e,
-            LinearExpression(
-                [MonomialTermExpression((1, m.a)), MonomialTermExpression((1, m.b)), 5]
-            ),
-        )
+        self.assertExpressionsEqual(e, LinearExpression([m.a, m.b, 5]))
 
         #       +
         #      / \
@@ -710,12 +689,7 @@ def test_nestedSum(self):
         #       a   b
         e1 = m.a + m.b
         e = 5 + e1
-        self.assertExpressionsEqual(
-            e,
-            LinearExpression(
-                [MonomialTermExpression((1, m.a)), MonomialTermExpression((1, m.b)), 5]
-            ),
-        )
+        self.assertExpressionsEqual(e, LinearExpression([m.a, m.b, 5]))
 
         #           +
         #          / \
@@ -724,16 +698,7 @@ def test_nestedSum(self):
         #       a   b
         e1 = m.a + m.b
         e = e1 + m.c
-        self.assertExpressionsEqual(
-            e,
-            LinearExpression(
-                [
-                    MonomialTermExpression((1, m.a)),
-                    MonomialTermExpression((1, m.b)),
-                    MonomialTermExpression((1, m.c)),
-                ]
-            ),
-        )
+        self.assertExpressionsEqual(e, LinearExpression([m.a, m.b, m.c]))
 
         #       +
         #      / \
@@ -742,16 +707,7 @@ def test_nestedSum(self):
         #       a   b
         e1 = m.a + m.b
         e = m.c + e1
-        self.assertExpressionsEqual(
-            e,
-            LinearExpression(
-                [
-                    MonomialTermExpression((1, m.a)),
-                    MonomialTermExpression((1, m.b)),
-                    MonomialTermExpression((1, m.c)),
-                ]
-            ),
-        )
+        self.assertExpressionsEqual(e, LinearExpression([m.a, m.b, m.c]))
 
         #            +
         #          /   \
@@ -762,17 +718,7 @@ def test_nestedSum(self):
         e2 = m.c + m.d
         e = e1 + e2
         #
-        self.assertExpressionsEqual(
-            e,
-            LinearExpression(
-                [
-                    MonomialTermExpression((1, m.a)),
-                    MonomialTermExpression((1, m.b)),
-                    MonomialTermExpression((1, m.c)),
-                    MonomialTermExpression((1, m.d)),
-                ]
-            ),
-        )
+        self.assertExpressionsEqual(e, LinearExpression([m.a, m.b, m.c, m.d]))
 
     def test_nestedSum2(self):
         #
@@ -798,22 +744,7 @@ def test_nestedSum2(self):
 
         self.assertExpressionsEqual(
             e,
-            SumExpression(
-                [
-                    ProductExpression(
-                        (
-                            2,
-                            LinearExpression(
-                                [
-                                    MonomialTermExpression((1, m.a)),
-                                    MonomialTermExpression((1, m.b)),
-                                ]
-                            ),
-                        )
-                    ),
-                    m.c,
-                ]
-            ),
+            SumExpression([ProductExpression((2, LinearExpression([m.a, m.b]))), m.c]),
         )
 
         #         *
@@ -834,20 +765,7 @@ def test_nestedSum2(self):
                 (
                     3,
                     SumExpression(
-                        [
-                            ProductExpression(
-                                (
-                                    2,
-                                    LinearExpression(
-                                        [
-                                            MonomialTermExpression((1, m.a)),
-                                            MonomialTermExpression((1, m.b)),
-                                        ]
-                                    ),
-                                )
-                            ),
-                            m.c,
-                        ]
+                        [ProductExpression((2, LinearExpression([m.a, m.b]))), m.c]
                     ),
                 )
             ),
@@ -891,10 +809,7 @@ def test_sumOf_nestedTrivialProduct(self):
         e = e1 + m.b
         #
         self.assertExpressionsEqual(
-            e,
-            LinearExpression(
-                [MonomialTermExpression((5, m.a)), MonomialTermExpression((1, m.b))]
-            ),
+            e, LinearExpression([MonomialTermExpression((5, m.a)), m.b])
         )
 
         #       +
@@ -905,10 +820,7 @@ def test_sumOf_nestedTrivialProduct(self):
         e = m.b + e1
         #
         self.assertExpressionsEqual(
-            e,
-            LinearExpression(
-                [MonomialTermExpression((1, m.b)), MonomialTermExpression((5, m.a))]
-            ),
+            e, LinearExpression([m.b, MonomialTermExpression((5, m.a))])
         )
 
         #            +
@@ -920,14 +832,7 @@ def test_sumOf_nestedTrivialProduct(self):
         e = e1 + e2
         #
         self.assertExpressionsEqual(
-            e,
-            LinearExpression(
-                [
-                    MonomialTermExpression((1, m.b)),
-                    MonomialTermExpression((1, m.c)),
-                    MonomialTermExpression((5, m.a)),
-                ]
-            ),
+            e, LinearExpression([m.b, m.c, MonomialTermExpression((5, m.a))])
         )
 
         #            +
@@ -939,14 +844,7 @@ def test_sumOf_nestedTrivialProduct(self):
         e = e2 + e1
         #
         self.assertExpressionsEqual(
-            e,
-            LinearExpression(
-                [
-                    MonomialTermExpression((1, m.b)),
-                    MonomialTermExpression((1, m.c)),
-                    MonomialTermExpression((5, m.a)),
-                ]
-            ),
+            e, LinearExpression([m.b, m.c, MonomialTermExpression((5, m.a))])
         )
 
     def test_simpleDiff(self):
@@ -962,10 +860,7 @@ def test_simpleDiff(self):
         #  a   b
         e = m.a - m.b
         self.assertExpressionsEqual(
-            e,
-            LinearExpression(
-                [MonomialTermExpression((1, m.a)), MonomialTermExpression((-1, m.b))]
-            ),
+            e, LinearExpression([m.a, MonomialTermExpression((-1, m.b))])
         )
 
     def test_constDiff(self):
@@ -978,9 +873,7 @@ def test_constDiff(self):
         #    -
         #   / \
         #  a   5
-        self.assertExpressionsEqual(
-            m.a - 5, LinearExpression([MonomialTermExpression((1, m.a)), -5])
-        )
+        self.assertExpressionsEqual(m.a - 5, LinearExpression([m.a, -5]))
 
         #    -
         #   / \
@@ -1002,10 +895,7 @@ def test_paramDiff(self):
         #  a   p
         e = m.a - m.p
         self.assertExpressionsEqual(
-            e,
-            LinearExpression(
-                [MonomialTermExpression((1, m.a)), NPV_NegationExpression((m.p,))]
-            ),
+            e, LinearExpression([m.a, NPV_NegationExpression((m.p,))])
         )
 
         #      -
@@ -1079,14 +969,7 @@ def test_nestedDiff(self):
         e1 = m.a - m.b
         e = e1 - 5
         self.assertExpressionsEqual(
-            e,
-            LinearExpression(
-                [
-                    MonomialTermExpression((1, m.a)),
-                    MonomialTermExpression((-1, m.b)),
-                    -5,
-                ]
-            ),
+            e, LinearExpression([m.a, MonomialTermExpression((-1, m.b)), -5])
         )
 
         #       -
@@ -1102,14 +985,7 @@ def test_nestedDiff(self):
                 [
                     5,
                     NegationExpression(
-                        (
-                            LinearExpression(
-                                [
-                                    MonomialTermExpression((1, m.a)),
-                                    MonomialTermExpression((-1, m.b)),
-                                ]
-                            ),
-                        )
+                        (LinearExpression([m.a, MonomialTermExpression((-1, m.b))]),)
                     ),
                 ]
             ),
@@ -1126,7 +1002,7 @@ def test_nestedDiff(self):
             e,
             LinearExpression(
                 [
-                    MonomialTermExpression((1, m.a)),
+                    m.a,
                     MonomialTermExpression((-1, m.b)),
                     MonomialTermExpression((-1, m.c)),
                 ]
@@ -1146,14 +1022,7 @@ def test_nestedDiff(self):
                 [
                     m.c,
                     NegationExpression(
-                        (
-                            LinearExpression(
-                                [
-                                    MonomialTermExpression((1, m.a)),
-                                    MonomialTermExpression((-1, m.b)),
-                                ]
-                            ),
-                        )
+                        (LinearExpression([m.a, MonomialTermExpression((-1, m.b))]),)
                     ),
                 ]
             ),
@@ -1171,21 +1040,9 @@ def test_nestedDiff(self):
             e,
             SumExpression(
                 [
-                    LinearExpression(
-                        [
-                            MonomialTermExpression((1, m.a)),
-                            MonomialTermExpression((-1, m.b)),
-                        ]
-                    ),
+                    LinearExpression([m.a, MonomialTermExpression((-1, m.b))]),
                     NegationExpression(
-                        (
-                            LinearExpression(
-                                [
-                                    MonomialTermExpression((1, m.c)),
-                                    MonomialTermExpression((-1, m.d)),
-                                ]
-                            ),
-                        )
+                        (LinearExpression([m.c, MonomialTermExpression((-1, m.d))]),)
                     ),
                 ]
             ),
@@ -1382,10 +1239,7 @@ def test_sumOf_nestedTrivialProduct2(self):
         self.assertExpressionsEqual(
             e,
             LinearExpression(
-                [
-                    MonomialTermExpression((1, m.b)),
-                    MonomialTermExpression((NPV_NegationExpression((m.p,)), m.a)),
-                ]
+                [m.b, MonomialTermExpression((NPV_NegationExpression((m.p,)), m.a))]
             ),
         )
 
@@ -1403,14 +1257,7 @@ def test_sumOf_nestedTrivialProduct2(self):
                 [
                     MonomialTermExpression((m.p, m.a)),
                     NegationExpression(
-                        (
-                            LinearExpression(
-                                [
-                                    MonomialTermExpression((1, m.b)),
-                                    MonomialTermExpression((-1, m.c)),
-                                ]
-                            ),
-                        )
+                        (LinearExpression([m.b, MonomialTermExpression((-1, m.c))]),)
                     ),
                 ]
             ),
@@ -1424,12 +1271,11 @@ def test_sumOf_nestedTrivialProduct2(self):
         e1 = m.a * m.p
         e2 = m.b - m.c
         e = e2 - e1
-        self.maxDiff = None
         self.assertExpressionsEqual(
             e,
             LinearExpression(
                 [
-                    MonomialTermExpression((1, m.b)),
+                    m.b,
                     MonomialTermExpression((-1, m.c)),
                     MonomialTermExpression((NPV_NegationExpression((m.p,)), m.a)),
                 ]
@@ -1599,22 +1445,7 @@ def test_nestedProduct2(self):
         self.assertExpressionsEqual(
             e,
             ProductExpression(
-                (
-                    LinearExpression(
-                        [
-                            MonomialTermExpression((1, m.a)),
-                            MonomialTermExpression((1, m.b)),
-                            MonomialTermExpression((1, m.c)),
-                        ]
-                    ),
-                    LinearExpression(
-                        [
-                            MonomialTermExpression((1, m.a)),
-                            MonomialTermExpression((1, m.b)),
-                            MonomialTermExpression((1, m.d)),
-                        ]
-                    ),
-                )
+                (LinearExpression([m.a, m.b, m.c]), LinearExpression([m.a, m.b, m.d]))
             ),
         )
         # Verify shared args...
@@ -1639,9 +1470,7 @@ def test_nestedProduct2(self):
         e3 = e1 * m.d
         e = e2 * e3
         #
-        inner = LinearExpression(
-            [MonomialTermExpression((1, m.a)), MonomialTermExpression((1, m.b))]
-        )
+        inner = LinearExpression([m.a, m.b])
         self.assertExpressionsEqual(
             e,
             ProductExpression(
@@ -2035,10 +1864,10 @@ def test_sum(self):
         model.p = Param(mutable=True)
 
         expr = 5 + model.a + model.a
-        self.assertEqual("sum(5, mon(1, a), mon(1, a))", str(expr))
+        self.assertEqual("sum(5, a, a)", str(expr))
 
         expr += 5
-        self.assertEqual("sum(5, mon(1, a), mon(1, a), 5)", str(expr))
+        self.assertEqual("sum(5, a, a, 5)", str(expr))
 
         expr = 2 + model.p
         self.assertEqual("sum(2, p)", str(expr))
@@ -2054,24 +1883,18 @@ def test_linearsum(self):
 
         expr = quicksum(i * model.a[i] for i in A)
         self.assertEqual(
-            "sum(mon(0, a[0]), mon(1, a[1]), mon(2, a[2]), mon(3, a[3]), "
-            "mon(4, a[4]))",
+            "sum(mon(0, a[0]), a[1], mon(2, a[2]), mon(3, a[3]), " "mon(4, a[4]))",
             str(expr),
         )
 
         expr = quicksum((i - 2) * model.a[i] for i in A)
         self.assertEqual(
-            "sum(mon(-2, a[0]), mon(-1, a[1]), mon(0, a[2]), mon(1, a[3]), "
-            "mon(2, a[4]))",
+            "sum(mon(-2, a[0]), mon(-1, a[1]), mon(0, a[2]), a[3], " "mon(2, a[4]))",
             str(expr),
         )
 
         expr = quicksum(model.a[i] for i in A)
-        self.assertEqual(
-            "sum(mon(1, a[0]), mon(1, a[1]), mon(1, a[2]), mon(1, a[3]), "
-            "mon(1, a[4]))",
-            str(expr),
-        )
+        self.assertEqual("sum(a[0], a[1], a[2], a[3], a[4])", str(expr))
 
         model.p[1].value = 0
         model.p[3].value = 3
@@ -2139,10 +1962,10 @@ def test_inequality(self):
         self.assertEqual("5  <=  a  <  10", str(expr))
 
         expr = 5 <= model.a + 5
-        self.assertEqual("5  <=  sum(mon(1, a), 5)", str(expr))
+        self.assertEqual("5  <=  sum(a, 5)", str(expr))
 
         expr = expr < 10
-        self.assertEqual("5  <=  sum(mon(1, a), 5)  <  10", str(expr))
+        self.assertEqual("5  <=  sum(a, 5)  <  10", str(expr))
 
     def test_equality(self):
         #
@@ -2167,10 +1990,10 @@ def test_equality(self):
         self.assertEqual("a  ==  10", str(expr))
 
         expr = 5 == model.a + 5
-        self.assertEqual("sum(mon(1, a), 5)  ==  5", str(expr))
+        self.assertEqual("sum(a, 5)  ==  5", str(expr))
 
         expr = model.a + 5 == 5
-        self.assertEqual("sum(mon(1, a), 5)  ==  5", str(expr))
+        self.assertEqual("sum(a, 5)  ==  5", str(expr))
 
     def test_getitem(self):
         m = ConcreteModel()
@@ -2207,7 +2030,7 @@ def test_small_expression(self):
         expr = abs(expr)
         self.assertEqual(
             "abs(neg(pow(2, div(2, prod(2, sum(1, neg(pow(div(prod(sum("
-            "mon(1, a), 1, -1), a), a), b)), 1))))))",
+            "a, 1, -1), a), a), b)), 1))))))",
             str(expr),
         )
 
@@ -3755,13 +3578,7 @@ def test_summation1(self):
         self.assertExpressionsEqual(
             e,
             LinearExpression(
-                [
-                    MonomialTermExpression((1, self.m.a[1])),
-                    MonomialTermExpression((1, self.m.a[2])),
-                    MonomialTermExpression((1, self.m.a[3])),
-                    MonomialTermExpression((1, self.m.a[4])),
-                    MonomialTermExpression((1, self.m.a[5])),
-                ]
+                [self.m.a[1], self.m.a[2], self.m.a[3], self.m.a[4], self.m.a[5]]
             ),
         )
 
@@ -3873,16 +3690,16 @@ def test_summation_compression(self):
             e,
             LinearExpression(
                 [
-                    MonomialTermExpression((1, self.m.a[1])),
-                    MonomialTermExpression((1, self.m.a[2])),
-                    MonomialTermExpression((1, self.m.a[3])),
-                    MonomialTermExpression((1, self.m.a[4])),
-                    MonomialTermExpression((1, self.m.a[5])),
-                    MonomialTermExpression((1, self.m.b[1])),
-                    MonomialTermExpression((1, self.m.b[2])),
-                    MonomialTermExpression((1, self.m.b[3])),
-                    MonomialTermExpression((1, self.m.b[4])),
-                    MonomialTermExpression((1, self.m.b[5])),
+                    self.m.a[1],
+                    self.m.a[2],
+                    self.m.a[3],
+                    self.m.a[4],
+                    self.m.a[5],
+                    self.m.b[1],
+                    self.m.b[2],
+                    self.m.b[3],
+                    self.m.b[4],
+                    self.m.b[5],
                 ]
             ),
         )
@@ -3913,13 +3730,7 @@ def test_deprecation(self):
         self.assertExpressionsEqual(
             e,
             LinearExpression(
-                [
-                    MonomialTermExpression((1, self.m.a[1])),
-                    MonomialTermExpression((1, self.m.a[2])),
-                    MonomialTermExpression((1, self.m.a[3])),
-                    MonomialTermExpression((1, self.m.a[4])),
-                    MonomialTermExpression((1, self.m.a[5])),
-                ]
+                [self.m.a[1], self.m.a[2], self.m.a[3], self.m.a[4], self.m.a[5]]
             ),
         )
 
@@ -3929,13 +3740,7 @@ def test_summation1(self):
         self.assertExpressionsEqual(
             e,
             LinearExpression(
-                [
-                    MonomialTermExpression((1, self.m.a[1])),
-                    MonomialTermExpression((1, self.m.a[2])),
-                    MonomialTermExpression((1, self.m.a[3])),
-                    MonomialTermExpression((1, self.m.a[4])),
-                    MonomialTermExpression((1, self.m.a[5])),
-                ]
+                [self.m.a[1], self.m.a[2], self.m.a[3], self.m.a[4], self.m.a[5]]
             ),
         )
 
@@ -4157,15 +3962,15 @@ def test_SumExpression(self):
             self.assertEqual(expr2(), 15)
             self.assertNotEqual(id(expr1), id(expr2))
             self.assertNotEqual(id(expr1._args_), id(expr2._args_))
-            self.assertIs(expr1.arg(0).arg(1), expr2.arg(0).arg(1))
-            self.assertIs(expr1.arg(1).arg(1), expr2.arg(1).arg(1))
+            self.assertIs(expr1.arg(0), expr2.arg(0))
+            self.assertIs(expr1.arg(1), expr2.arg(1))
             expr1 += self.m.b
             self.assertEqual(expr1(), 25)
             self.assertEqual(expr2(), 15)
             self.assertNotEqual(id(expr1), id(expr2))
             self.assertNotEqual(id(expr1._args_), id(expr2._args_))
-            self.assertIs(expr1.arg(0).arg(1), expr2.arg(0).arg(1))
-            self.assertIs(expr1.arg(1).arg(1), expr2.arg(1).arg(1))
+            self.assertIs(expr1.arg(0), expr2.arg(0))
+            self.assertIs(expr1.arg(1), expr2.arg(1))
             #
             total = counter.count - start
             self.assertEqual(total, 1)
@@ -4342,9 +4147,9 @@ def test_productOfExpressions(self):
             self.assertEqual(expr1.arg(1).nargs(), 2)
             self.assertEqual(expr2.arg(1).nargs(), 2)
 
-            self.assertIs(expr1.arg(0).arg(0).arg(1), expr2.arg(0).arg(0).arg(1))
-            self.assertIs(expr1.arg(0).arg(1).arg(1), expr2.arg(0).arg(1).arg(1))
-            self.assertIs(expr1.arg(1).arg(0).arg(1), expr2.arg(1).arg(0).arg(1))
+            self.assertIs(expr1.arg(0).arg(0), expr2.arg(0).arg(0))
+            self.assertIs(expr1.arg(0).arg(1), expr2.arg(0).arg(1))
+            self.assertIs(expr1.arg(1).arg(0), expr2.arg(1).arg(0))
 
             expr1 *= self.m.b
             self.assertEqual(expr1(), 1500)
@@ -4383,8 +4188,8 @@ def test_productOfExpressions_div(self):
             self.assertEqual(expr1.arg(1).nargs(), 2)
             self.assertEqual(expr2.arg(1).nargs(), 2)
 
-            self.assertIs(expr1.arg(0).arg(0).arg(1), expr2.arg(0).arg(0).arg(1))
-            self.assertIs(expr1.arg(0).arg(1).arg(1), expr2.arg(0).arg(1).arg(1))
+            self.assertIs(expr1.arg(0).arg(0), expr2.arg(0).arg(0))
+            self.assertIs(expr1.arg(0).arg(1), expr2.arg(0).arg(1))
 
             expr1 /= self.m.b
             self.assertAlmostEqual(expr1(), 0.15)
@@ -5215,18 +5020,7 @@ def test_pow_other(self):
             e += m.v[0] + m.v[1]
             e = m.v[0] ** e
             self.assertExpressionsEqual(
-                e,
-                PowExpression(
-                    (
-                        m.v[0],
-                        LinearExpression(
-                            [
-                                MonomialTermExpression((1, m.v[0])),
-                                MonomialTermExpression((1, m.v[1])),
-                            ]
-                        ),
-                    )
-                ),
+                e, PowExpression((m.v[0], LinearExpression([m.v[0], m.v[1]])))
             )
 
 
diff --git a/pyomo/core/tests/unit/test_numeric_expr_api.py b/pyomo/core/tests/unit/test_numeric_expr_api.py
index 69cb43f3ad5..923f78af1be 100644
--- a/pyomo/core/tests/unit/test_numeric_expr_api.py
+++ b/pyomo/core/tests/unit/test_numeric_expr_api.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -223,7 +223,7 @@ def test_negation(self):
         self.assertEqual(is_fixed(e), False)
         self.assertEqual(value(e), -15)
         self.assertEqual(str(e), "- (x + 2*x)")
-        self.assertEqual(e.to_string(verbose=True), "neg(sum(mon(1, x), mon(2, x)))")
+        self.assertEqual(e.to_string(verbose=True), "neg(sum(x, mon(2, x)))")
 
         # This can't occur through operator overloading, but could
         # through expression substitution
@@ -634,8 +634,7 @@ def test_linear(self):
         self.assertEqual(value(e), 1 + 4 + 5 + 2)
         self.assertEqual(str(e), "0*x[0] + x[1] + 2*x[2] + 5 + y - 3")
         self.assertEqual(
-            e.to_string(verbose=True),
-            "sum(mon(0, x[0]), mon(1, x[1]), mon(2, x[2]), 5, mon(1, y), -3)",
+            e.to_string(verbose=True), "sum(mon(0, x[0]), x[1], mon(2, x[2]), 5, y, -3)"
         )
 
         self.assertIs(type(e), LinearExpression)
@@ -701,7 +700,7 @@ def test_expr_if(self):
         )
         self.assertEqual(
             e.to_string(verbose=True),
-            "Expr_if( ( 5  <=  y ), then=( sum(mon(1, x[0]), 5) ), else=( pow(x[1], 2) ) )",
+            "Expr_if( ( 5  <=  y ), then=( sum(x[0], 5) ), else=( pow(x[1], 2) ) )",
         )
 
         m.y.fix()
@@ -972,9 +971,7 @@ def test_sum(self):
         f = e.create_node_with_local_data((m.p, m.x))
         self.assertIsNot(f, e)
         self.assertIs(type(f), LinearExpression)
-        assertExpressionsStructurallyEqual(
-            self, f.args, [m.p, MonomialTermExpression((1, m.x))]
-        )
+        assertExpressionsStructurallyEqual(self, f.args, [m.p, m.x])
 
         f = e.create_node_with_local_data((m.p, m.x**2))
         self.assertIsNot(f, e)
diff --git a/pyomo/core/tests/unit/test_numeric_expr_dispatcher.py b/pyomo/core/tests/unit/test_numeric_expr_dispatcher.py
index 3e9e160b1b1..bb7a291e67d 100644
--- a/pyomo/core/tests/unit/test_numeric_expr_dispatcher.py
+++ b/pyomo/core/tests/unit/test_numeric_expr_dispatcher.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -123,8 +123,6 @@ def setUp(self):
         self.mutable_l3 = _MutableNPVSumExpression([self.npv])
 
         # often repeated reference expressions
-        self.mon_bin = MonomialTermExpression((1, self.bin))
-        self.mon_var = MonomialTermExpression((1, self.var))
         self.minus_bin = MonomialTermExpression((-1, self.bin))
         self.minus_npv = NPV_NegationExpression((self.npv,))
         self.minus_param_mut = NPV_NegationExpression((self.param_mut,))
@@ -368,38 +366,34 @@ def test_add_asbinary(self):
             # BooleanVar objects do not support addition
             (self.asbinary, self.asbinary, NotImplemented),
             (self.asbinary, self.zero, self.bin),
-            (self.asbinary, self.one, LinearExpression([self.mon_bin, 1])),
+            (self.asbinary, self.one, LinearExpression([self.bin, 1])),
             # 4:
-            (self.asbinary, self.native, LinearExpression([self.mon_bin, 5])),
-            (self.asbinary, self.npv, LinearExpression([self.mon_bin, self.npv])),
-            (self.asbinary, self.param, LinearExpression([self.mon_bin, 6])),
+            (self.asbinary, self.native, LinearExpression([self.bin, 5])),
+            (self.asbinary, self.npv, LinearExpression([self.bin, self.npv])),
+            (self.asbinary, self.param, LinearExpression([self.bin, 6])),
             (
                 self.asbinary,
                 self.param_mut,
-                LinearExpression([self.mon_bin, self.param_mut]),
+                LinearExpression([self.bin, self.param_mut]),
             ),
             # 8:
-            (self.asbinary, self.var, LinearExpression([self.mon_bin, self.mon_var])),
+            (self.asbinary, self.var, LinearExpression([self.bin, self.var])),
             (
                 self.asbinary,
                 self.mon_native,
-                LinearExpression([self.mon_bin, self.mon_native]),
+                LinearExpression([self.bin, self.mon_native]),
             ),
             (
                 self.asbinary,
                 self.mon_param,
-                LinearExpression([self.mon_bin, self.mon_param]),
-            ),
-            (
-                self.asbinary,
-                self.mon_npv,
-                LinearExpression([self.mon_bin, self.mon_npv]),
+                LinearExpression([self.bin, self.mon_param]),
             ),
+            (self.asbinary, self.mon_npv, LinearExpression([self.bin, self.mon_npv])),
             # 12:
             (
                 self.asbinary,
                 self.linear,
-                LinearExpression(self.linear.args + [self.mon_bin]),
+                LinearExpression(self.linear.args + [self.bin]),
             ),
             (self.asbinary, self.sum, SumExpression(self.sum.args + [self.bin])),
             (self.asbinary, self.other, SumExpression([self.bin, self.other])),
@@ -408,7 +402,7 @@ def test_add_asbinary(self):
             (
                 self.asbinary,
                 self.mutable_l1,
-                LinearExpression([self.mon_bin, self.mon_npv]),
+                LinearExpression([self.bin, self.mon_npv]),
             ),
             (
                 self.asbinary,
@@ -416,13 +410,9 @@ def test_add_asbinary(self):
                 SumExpression(self.mutable_l2.args + [self.bin]),
             ),
             (self.asbinary, self.param0, self.bin),
-            (self.asbinary, self.param1, LinearExpression([self.mon_bin, 1])),
+            (self.asbinary, self.param1, LinearExpression([self.bin, 1])),
             # 20:
-            (
-                self.asbinary,
-                self.mutable_l3,
-                LinearExpression([self.mon_bin, self.npv]),
-            ),
+            (self.asbinary, self.mutable_l3, LinearExpression([self.bin, self.npv])),
         ]
         self._run_cases(tests, operator.add)
         self._run_cases(tests, operator.iadd)
@@ -462,7 +452,7 @@ def test_add_zero(self):
     def test_add_one(self):
         tests = [
             (self.one, self.invalid, NotImplemented),
-            (self.one, self.asbinary, LinearExpression([1, self.mon_bin])),
+            (self.one, self.asbinary, LinearExpression([1, self.bin])),
             (self.one, self.zero, 1),
             (self.one, self.one, 2),
             # 4:
@@ -471,7 +461,7 @@ def test_add_one(self):
             (self.one, self.param, 7),
             (self.one, self.param_mut, NPV_SumExpression([1, self.param_mut])),
             # 8:
-            (self.one, self.var, LinearExpression([1, self.mon_var])),
+            (self.one, self.var, LinearExpression([1, self.var])),
             (self.one, self.mon_native, LinearExpression([1, self.mon_native])),
             (self.one, self.mon_param, LinearExpression([1, self.mon_param])),
             (self.one, self.mon_npv, LinearExpression([1, self.mon_npv])),
@@ -494,7 +484,7 @@ def test_add_one(self):
     def test_add_native(self):
         tests = [
             (self.native, self.invalid, NotImplemented),
-            (self.native, self.asbinary, LinearExpression([5, self.mon_bin])),
+            (self.native, self.asbinary, LinearExpression([5, self.bin])),
             (self.native, self.zero, 5),
             (self.native, self.one, 6),
             # 4:
@@ -503,7 +493,7 @@ def test_add_native(self):
             (self.native, self.param, 11),
             (self.native, self.param_mut, NPV_SumExpression([5, self.param_mut])),
             # 8:
-            (self.native, self.var, LinearExpression([5, self.mon_var])),
+            (self.native, self.var, LinearExpression([5, self.var])),
             (self.native, self.mon_native, LinearExpression([5, self.mon_native])),
             (self.native, self.mon_param, LinearExpression([5, self.mon_param])),
             (self.native, self.mon_npv, LinearExpression([5, self.mon_npv])),
@@ -530,7 +520,7 @@ def test_add_native(self):
     def test_add_npv(self):
         tests = [
             (self.npv, self.invalid, NotImplemented),
-            (self.npv, self.asbinary, LinearExpression([self.npv, self.mon_bin])),
+            (self.npv, self.asbinary, LinearExpression([self.npv, self.bin])),
             (self.npv, self.zero, self.npv),
             (self.npv, self.one, NPV_SumExpression([self.npv, 1])),
             # 4:
@@ -539,7 +529,7 @@ def test_add_npv(self):
             (self.npv, self.param, NPV_SumExpression([self.npv, 6])),
             (self.npv, self.param_mut, NPV_SumExpression([self.npv, self.param_mut])),
             # 8:
-            (self.npv, self.var, LinearExpression([self.npv, self.mon_var])),
+            (self.npv, self.var, LinearExpression([self.npv, self.var])),
             (self.npv, self.mon_native, LinearExpression([self.npv, self.mon_native])),
             (self.npv, self.mon_param, LinearExpression([self.npv, self.mon_param])),
             (self.npv, self.mon_npv, LinearExpression([self.npv, self.mon_npv])),
@@ -570,7 +560,7 @@ def test_add_npv(self):
     def test_add_param(self):
         tests = [
             (self.param, self.invalid, NotImplemented),
-            (self.param, self.asbinary, LinearExpression([6, self.mon_bin])),
+            (self.param, self.asbinary, LinearExpression([6, self.bin])),
             (self.param, self.zero, 6),
             (self.param, self.one, 7),
             # 4:
@@ -579,7 +569,7 @@ def test_add_param(self):
             (self.param, self.param, 12),
             (self.param, self.param_mut, NPV_SumExpression([6, self.param_mut])),
             # 8:
-            (self.param, self.var, LinearExpression([6, self.mon_var])),
+            (self.param, self.var, LinearExpression([6, self.var])),
             (self.param, self.mon_native, LinearExpression([6, self.mon_native])),
             (self.param, self.mon_param, LinearExpression([6, self.mon_param])),
             (self.param, self.mon_npv, LinearExpression([6, self.mon_npv])),
@@ -605,7 +595,7 @@ def test_add_param_mut(self):
             (
                 self.param_mut,
                 self.asbinary,
-                LinearExpression([self.param_mut, self.mon_bin]),
+                LinearExpression([self.param_mut, self.bin]),
             ),
             (self.param_mut, self.zero, self.param_mut),
             (self.param_mut, self.one, NPV_SumExpression([self.param_mut, 1])),
@@ -619,11 +609,7 @@ def test_add_param_mut(self):
                 NPV_SumExpression([self.param_mut, self.param_mut]),
             ),
             # 8:
-            (
-                self.param_mut,
-                self.var,
-                LinearExpression([self.param_mut, self.mon_var]),
-            ),
+            (self.param_mut, self.var, LinearExpression([self.param_mut, self.var])),
             (
                 self.param_mut,
                 self.mon_native,
@@ -674,37 +660,21 @@ def test_add_param_mut(self):
     def test_add_var(self):
         tests = [
             (self.var, self.invalid, NotImplemented),
-            (self.var, self.asbinary, LinearExpression([self.mon_var, self.mon_bin])),
+            (self.var, self.asbinary, LinearExpression([self.var, self.bin])),
             (self.var, self.zero, self.var),
-            (self.var, self.one, LinearExpression([self.mon_var, 1])),
+            (self.var, self.one, LinearExpression([self.var, 1])),
             # 4:
-            (self.var, self.native, LinearExpression([self.mon_var, 5])),
-            (self.var, self.npv, LinearExpression([self.mon_var, self.npv])),
-            (self.var, self.param, LinearExpression([self.mon_var, 6])),
-            (
-                self.var,
-                self.param_mut,
-                LinearExpression([self.mon_var, self.param_mut]),
-            ),
+            (self.var, self.native, LinearExpression([self.var, 5])),
+            (self.var, self.npv, LinearExpression([self.var, self.npv])),
+            (self.var, self.param, LinearExpression([self.var, 6])),
+            (self.var, self.param_mut, LinearExpression([self.var, self.param_mut])),
             # 8:
-            (self.var, self.var, LinearExpression([self.mon_var, self.mon_var])),
-            (
-                self.var,
-                self.mon_native,
-                LinearExpression([self.mon_var, self.mon_native]),
-            ),
-            (
-                self.var,
-                self.mon_param,
-                LinearExpression([self.mon_var, self.mon_param]),
-            ),
-            (self.var, self.mon_npv, LinearExpression([self.mon_var, self.mon_npv])),
+            (self.var, self.var, LinearExpression([self.var, self.var])),
+            (self.var, self.mon_native, LinearExpression([self.var, self.mon_native])),
+            (self.var, self.mon_param, LinearExpression([self.var, self.mon_param])),
+            (self.var, self.mon_npv, LinearExpression([self.var, self.mon_npv])),
             # 12:
-            (
-                self.var,
-                self.linear,
-                LinearExpression(self.linear.args + [self.mon_var]),
-            ),
+            (self.var, self.linear, LinearExpression(self.linear.args + [self.var])),
             (self.var, self.sum, SumExpression(self.sum.args + [self.var])),
             (self.var, self.other, SumExpression([self.var, self.other])),
             (self.var, self.mutable_l0, self.var),
@@ -712,7 +682,7 @@ def test_add_var(self):
             (
                 self.var,
                 self.mutable_l1,
-                LinearExpression([self.mon_var] + self.mutable_l1.args),
+                LinearExpression([self.var] + self.mutable_l1.args),
             ),
             (
                 self.var,
@@ -720,13 +690,9 @@ def test_add_var(self):
                 SumExpression(self.mutable_l2.args + [self.var]),
             ),
             (self.var, self.param0, self.var),
-            (self.var, self.param1, LinearExpression([self.mon_var, 1])),
+            (self.var, self.param1, LinearExpression([self.var, 1])),
             # 20:
-            (
-                self.var,
-                self.mutable_l3,
-                LinearExpression([MonomialTermExpression((1, self.var)), self.npv]),
-            ),
+            (self.var, self.mutable_l3, LinearExpression([self.var, self.npv])),
         ]
         self._run_cases(tests, operator.add)
         self._run_cases(tests, operator.iadd)
@@ -737,7 +703,7 @@ def test_add_mon_native(self):
             (
                 self.mon_native,
                 self.asbinary,
-                LinearExpression([self.mon_native, self.mon_bin]),
+                LinearExpression([self.mon_native, self.bin]),
             ),
             (self.mon_native, self.zero, self.mon_native),
             (self.mon_native, self.one, LinearExpression([self.mon_native, 1])),
@@ -751,11 +717,7 @@ def test_add_mon_native(self):
                 LinearExpression([self.mon_native, self.param_mut]),
             ),
             # 8:
-            (
-                self.mon_native,
-                self.var,
-                LinearExpression([self.mon_native, self.mon_var]),
-            ),
+            (self.mon_native, self.var, LinearExpression([self.mon_native, self.var])),
             (
                 self.mon_native,
                 self.mon_native,
@@ -813,7 +775,7 @@ def test_add_mon_param(self):
             (
                 self.mon_param,
                 self.asbinary,
-                LinearExpression([self.mon_param, self.mon_bin]),
+                LinearExpression([self.mon_param, self.bin]),
             ),
             (self.mon_param, self.zero, self.mon_param),
             (self.mon_param, self.one, LinearExpression([self.mon_param, 1])),
@@ -827,11 +789,7 @@ def test_add_mon_param(self):
                 LinearExpression([self.mon_param, self.param_mut]),
             ),
             # 8:
-            (
-                self.mon_param,
-                self.var,
-                LinearExpression([self.mon_param, self.mon_var]),
-            ),
+            (self.mon_param, self.var, LinearExpression([self.mon_param, self.var])),
             (
                 self.mon_param,
                 self.mon_native,
@@ -882,11 +840,7 @@ def test_add_mon_param(self):
     def test_add_mon_npv(self):
         tests = [
             (self.mon_npv, self.invalid, NotImplemented),
-            (
-                self.mon_npv,
-                self.asbinary,
-                LinearExpression([self.mon_npv, self.mon_bin]),
-            ),
+            (self.mon_npv, self.asbinary, LinearExpression([self.mon_npv, self.bin])),
             (self.mon_npv, self.zero, self.mon_npv),
             (self.mon_npv, self.one, LinearExpression([self.mon_npv, 1])),
             # 4:
@@ -899,7 +853,7 @@ def test_add_mon_npv(self):
                 LinearExpression([self.mon_npv, self.param_mut]),
             ),
             # 8:
-            (self.mon_npv, self.var, LinearExpression([self.mon_npv, self.mon_var])),
+            (self.mon_npv, self.var, LinearExpression([self.mon_npv, self.var])),
             (
                 self.mon_npv,
                 self.mon_native,
@@ -949,7 +903,7 @@ def test_add_linear(self):
             (
                 self.linear,
                 self.asbinary,
-                LinearExpression(self.linear.args + [self.mon_bin]),
+                LinearExpression(self.linear.args + [self.bin]),
             ),
             (self.linear, self.zero, self.linear),
             (self.linear, self.one, LinearExpression(self.linear.args + [1])),
@@ -963,11 +917,7 @@ def test_add_linear(self):
                 LinearExpression(self.linear.args + [self.param_mut]),
             ),
             # 8:
-            (
-                self.linear,
-                self.var,
-                LinearExpression(self.linear.args + [self.mon_var]),
-            ),
+            (self.linear, self.var, LinearExpression(self.linear.args + [self.var])),
             (
                 self.linear,
                 self.mon_native,
@@ -1134,7 +1084,7 @@ def test_add_mutable_l1(self):
             (
                 self.mutable_l1,
                 self.asbinary,
-                LinearExpression(self.mutable_l1.args + [self.mon_bin]),
+                LinearExpression(self.mutable_l1.args + [self.bin]),
             ),
             (self.mutable_l1, self.zero, self.mon_npv),
             (self.mutable_l1, self.one, LinearExpression(self.mutable_l1.args + [1])),
@@ -1159,7 +1109,7 @@ def test_add_mutable_l1(self):
             (
                 self.mutable_l1,
                 self.var,
-                LinearExpression(self.mutable_l1.args + [self.mon_var]),
+                LinearExpression(self.mutable_l1.args + [self.var]),
             ),
             (
                 self.mutable_l1,
@@ -1341,7 +1291,7 @@ def test_add_param0(self):
     def test_add_param1(self):
         tests = [
             (self.param1, self.invalid, NotImplemented),
-            (self.param1, self.asbinary, LinearExpression([1, self.mon_bin])),
+            (self.param1, self.asbinary, LinearExpression([1, self.bin])),
             (self.param1, self.zero, 1),
             (self.param1, self.one, 2),
             # 4:
@@ -1350,7 +1300,7 @@ def test_add_param1(self):
             (self.param1, self.param, 7),
             (self.param1, self.param_mut, NPV_SumExpression([1, self.param_mut])),
             # 8:
-            (self.param1, self.var, LinearExpression([1, self.mon_var])),
+            (self.param1, self.var, LinearExpression([1, self.var])),
             (self.param1, self.mon_native, LinearExpression([1, self.mon_native])),
             (self.param1, self.mon_param, LinearExpression([1, self.mon_param])),
             (self.param1, self.mon_npv, LinearExpression([1, self.mon_npv])),
@@ -1380,7 +1330,7 @@ def test_add_mutable_l3(self):
             (
                 self.mutable_l3,
                 self.asbinary,
-                LinearExpression(self.mutable_l3.args + [self.mon_bin]),
+                LinearExpression(self.mutable_l3.args + [self.bin]),
             ),
             (self.mutable_l3, self.zero, self.npv),
             (self.mutable_l3, self.one, NPV_SumExpression(self.mutable_l3.args + [1])),
@@ -1409,7 +1359,7 @@ def test_add_mutable_l3(self):
             (
                 self.mutable_l3,
                 self.var,
-                LinearExpression(self.mutable_l3.args + [self.mon_var]),
+                LinearExpression(self.mutable_l3.args + [self.var]),
             ),
             (
                 self.mutable_l3,
@@ -1515,32 +1465,32 @@ def test_sub_asbinary(self):
             # BooleanVar objects do not support addition
             (self.asbinary, self.asbinary, NotImplemented),
             (self.asbinary, self.zero, self.bin),
-            (self.asbinary, self.one, LinearExpression([self.mon_bin, -1])),
+            (self.asbinary, self.one, LinearExpression([self.bin, -1])),
             # 4:
-            (self.asbinary, self.native, LinearExpression([self.mon_bin, -5])),
-            (self.asbinary, self.npv, LinearExpression([self.mon_bin, self.minus_npv])),
-            (self.asbinary, self.param, LinearExpression([self.mon_bin, -6])),
+            (self.asbinary, self.native, LinearExpression([self.bin, -5])),
+            (self.asbinary, self.npv, LinearExpression([self.bin, self.minus_npv])),
+            (self.asbinary, self.param, LinearExpression([self.bin, -6])),
             (
                 self.asbinary,
                 self.param_mut,
-                LinearExpression([self.mon_bin, self.minus_param_mut]),
+                LinearExpression([self.bin, self.minus_param_mut]),
             ),
             # 8:
-            (self.asbinary, self.var, LinearExpression([self.mon_bin, self.minus_var])),
+            (self.asbinary, self.var, LinearExpression([self.bin, self.minus_var])),
             (
                 self.asbinary,
                 self.mon_native,
-                LinearExpression([self.mon_bin, self.minus_mon_native]),
+                LinearExpression([self.bin, self.minus_mon_native]),
             ),
             (
                 self.asbinary,
                 self.mon_param,
-                LinearExpression([self.mon_bin, self.minus_mon_param]),
+                LinearExpression([self.bin, self.minus_mon_param]),
             ),
             (
                 self.asbinary,
                 self.mon_npv,
-                LinearExpression([self.mon_bin, self.minus_mon_npv]),
+                LinearExpression([self.bin, self.minus_mon_npv]),
             ),
             # 12:
             (self.asbinary, self.linear, SumExpression([self.bin, self.minus_linear])),
@@ -1551,7 +1501,7 @@ def test_sub_asbinary(self):
             (
                 self.asbinary,
                 self.mutable_l1,
-                LinearExpression([self.mon_bin, self.minus_mon_npv]),
+                LinearExpression([self.bin, self.minus_mon_npv]),
             ),
             (
                 self.asbinary,
@@ -1559,12 +1509,12 @@ def test_sub_asbinary(self):
                 SumExpression([self.bin, self.minus_mutable_l2]),
             ),
             (self.asbinary, self.param0, self.bin),
-            (self.asbinary, self.param1, LinearExpression([self.mon_bin, -1])),
+            (self.asbinary, self.param1, LinearExpression([self.bin, -1])),
             # 20:
             (
                 self.asbinary,
                 self.mutable_l3,
-                LinearExpression([self.mon_bin, self.minus_npv]),
+                LinearExpression([self.bin, self.minus_npv]),
             ),
         ]
         self._run_cases(tests, operator.sub)
@@ -1837,35 +1787,31 @@ def test_sub_param_mut(self):
     def test_sub_var(self):
         tests = [
             (self.var, self.invalid, NotImplemented),
-            (self.var, self.asbinary, LinearExpression([self.mon_var, self.minus_bin])),
+            (self.var, self.asbinary, LinearExpression([self.var, self.minus_bin])),
             (self.var, self.zero, self.var),
-            (self.var, self.one, LinearExpression([self.mon_var, -1])),
+            (self.var, self.one, LinearExpression([self.var, -1])),
             # 4:
-            (self.var, self.native, LinearExpression([self.mon_var, -5])),
-            (self.var, self.npv, LinearExpression([self.mon_var, self.minus_npv])),
-            (self.var, self.param, LinearExpression([self.mon_var, -6])),
+            (self.var, self.native, LinearExpression([self.var, -5])),
+            (self.var, self.npv, LinearExpression([self.var, self.minus_npv])),
+            (self.var, self.param, LinearExpression([self.var, -6])),
             (
                 self.var,
                 self.param_mut,
-                LinearExpression([self.mon_var, self.minus_param_mut]),
+                LinearExpression([self.var, self.minus_param_mut]),
             ),
             # 8:
-            (self.var, self.var, LinearExpression([self.mon_var, self.minus_var])),
+            (self.var, self.var, LinearExpression([self.var, self.minus_var])),
             (
                 self.var,
                 self.mon_native,
-                LinearExpression([self.mon_var, self.minus_mon_native]),
+                LinearExpression([self.var, self.minus_mon_native]),
             ),
             (
                 self.var,
                 self.mon_param,
-                LinearExpression([self.mon_var, self.minus_mon_param]),
-            ),
-            (
-                self.var,
-                self.mon_npv,
-                LinearExpression([self.mon_var, self.minus_mon_npv]),
+                LinearExpression([self.var, self.minus_mon_param]),
             ),
+            (self.var, self.mon_npv, LinearExpression([self.var, self.minus_mon_npv])),
             # 12:
             (
                 self.var,
@@ -1879,7 +1825,7 @@ def test_sub_var(self):
             (
                 self.var,
                 self.mutable_l1,
-                LinearExpression([self.mon_var, self.minus_mon_npv]),
+                LinearExpression([self.var, self.minus_mon_npv]),
             ),
             (
                 self.var,
@@ -1887,13 +1833,9 @@ def test_sub_var(self):
                 SumExpression([self.var, self.minus_mutable_l2]),
             ),
             (self.var, self.param0, self.var),
-            (self.var, self.param1, LinearExpression([self.mon_var, -1])),
+            (self.var, self.param1, LinearExpression([self.var, -1])),
             # 20:
-            (
-                self.var,
-                self.mutable_l3,
-                LinearExpression([self.mon_var, self.minus_npv]),
-            ),
+            (self.var, self.mutable_l3, LinearExpression([self.var, self.minus_npv])),
         ]
         self._run_cases(tests, operator.sub)
         self._run_cases(tests, operator.isub)
@@ -6511,7 +6453,7 @@ def test_mutable_nvp_iadd(self):
         mutable_npv = _MutableNPVSumExpression([])
         tests = [
             (mutable_npv, self.invalid, NotImplemented),
-            (mutable_npv, self.asbinary, _MutableLinearExpression([self.mon_bin])),
+            (mutable_npv, self.asbinary, _MutableLinearExpression([self.bin])),
             (mutable_npv, self.zero, _MutableNPVSumExpression([])),
             (mutable_npv, self.one, _MutableNPVSumExpression([1])),
             # 4:
@@ -6520,7 +6462,7 @@ def test_mutable_nvp_iadd(self):
             (mutable_npv, self.param, _MutableNPVSumExpression([6])),
             (mutable_npv, self.param_mut, _MutableNPVSumExpression([self.param_mut])),
             # 8:
-            (mutable_npv, self.var, _MutableLinearExpression([self.mon_var])),
+            (mutable_npv, self.var, _MutableLinearExpression([self.var])),
             (mutable_npv, self.mon_native, _MutableLinearExpression([self.mon_native])),
             (mutable_npv, self.mon_param, _MutableLinearExpression([self.mon_param])),
             (mutable_npv, self.mon_npv, _MutableLinearExpression([self.mon_npv])),
@@ -6546,20 +6488,20 @@ def test_mutable_nvp_iadd(self):
         mutable_npv = _MutableNPVSumExpression([10])
         tests = [
             (mutable_npv, self.invalid, NotImplemented),
-            (mutable_npv, self.asbinary, _MutableLinearExpression([10, self.mon_bin])),
+            (mutable_npv, self.asbinary, _MutableLinearExpression([10, self.bin])),
             (mutable_npv, self.zero, _MutableNPVSumExpression([10])),
-            (mutable_npv, self.one, _MutableNPVSumExpression([10, 1])),
+            (mutable_npv, self.one, _MutableNPVSumExpression([11])),
             # 4:
-            (mutable_npv, self.native, _MutableNPVSumExpression([10, 5])),
+            (mutable_npv, self.native, _MutableNPVSumExpression([15])),
             (mutable_npv, self.npv, _MutableNPVSumExpression([10, self.npv])),
-            (mutable_npv, self.param, _MutableNPVSumExpression([10, 6])),
+            (mutable_npv, self.param, _MutableNPVSumExpression([16])),
             (
                 mutable_npv,
                 self.param_mut,
                 _MutableNPVSumExpression([10, self.param_mut]),
             ),
             # 8:
-            (mutable_npv, self.var, _MutableLinearExpression([10, self.mon_var])),
+            (mutable_npv, self.var, _MutableLinearExpression([10, self.var])),
             (
                 mutable_npv,
                 self.mon_native,
@@ -6592,7 +6534,7 @@ def test_mutable_nvp_iadd(self):
                 _MutableSumExpression([10] + self.mutable_l2.args),
             ),
             (mutable_npv, self.param0, _MutableNPVSumExpression([10])),
-            (mutable_npv, self.param1, _MutableNPVSumExpression([10, 1])),
+            (mutable_npv, self.param1, _MutableNPVSumExpression([11])),
             # 20:
             (mutable_npv, self.mutable_l3, _MutableNPVSumExpression([10, self.npv])),
         ]
@@ -6602,7 +6544,7 @@ def test_mutable_lin_iadd(self):
         mutable_lin = _MutableLinearExpression([])
         tests = [
             (mutable_lin, self.invalid, NotImplemented),
-            (mutable_lin, self.asbinary, _MutableLinearExpression([self.mon_bin])),
+            (mutable_lin, self.asbinary, _MutableLinearExpression([self.bin])),
             (mutable_lin, self.zero, _MutableLinearExpression([])),
             (mutable_lin, self.one, _MutableLinearExpression([1])),
             # 4:
@@ -6611,7 +6553,7 @@ def test_mutable_lin_iadd(self):
             (mutable_lin, self.param, _MutableLinearExpression([6])),
             (mutable_lin, self.param_mut, _MutableLinearExpression([self.param_mut])),
             # 8:
-            (mutable_lin, self.var, _MutableLinearExpression([self.mon_var])),
+            (mutable_lin, self.var, _MutableLinearExpression([self.var])),
             (mutable_lin, self.mon_native, _MutableLinearExpression([self.mon_native])),
             (mutable_lin, self.mon_param, _MutableLinearExpression([self.mon_param])),
             (mutable_lin, self.mon_npv, _MutableLinearExpression([self.mon_npv])),
@@ -6634,81 +6576,69 @@ def test_mutable_lin_iadd(self):
         ]
         self._run_iadd_cases(tests, operator.iadd)
 
-        mutable_lin = _MutableLinearExpression([self.mon_bin])
+        mutable_lin = _MutableLinearExpression([self.bin])
         tests = [
             (mutable_lin, self.invalid, NotImplemented),
             (
                 mutable_lin,
                 self.asbinary,
-                _MutableLinearExpression([self.mon_bin, self.mon_bin]),
+                _MutableLinearExpression([self.bin, self.bin]),
             ),
-            (mutable_lin, self.zero, _MutableLinearExpression([self.mon_bin])),
-            (mutable_lin, self.one, _MutableLinearExpression([self.mon_bin, 1])),
+            (mutable_lin, self.zero, _MutableLinearExpression([self.bin])),
+            (mutable_lin, self.one, _MutableLinearExpression([self.bin, 1])),
             # 4:
-            (mutable_lin, self.native, _MutableLinearExpression([self.mon_bin, 5])),
-            (mutable_lin, self.npv, _MutableLinearExpression([self.mon_bin, self.npv])),
-            (mutable_lin, self.param, _MutableLinearExpression([self.mon_bin, 6])),
+            (mutable_lin, self.native, _MutableLinearExpression([self.bin, 5])),
+            (mutable_lin, self.npv, _MutableLinearExpression([self.bin, self.npv])),
+            (mutable_lin, self.param, _MutableLinearExpression([self.bin, 6])),
             (
                 mutable_lin,
                 self.param_mut,
-                _MutableLinearExpression([self.mon_bin, self.param_mut]),
+                _MutableLinearExpression([self.bin, self.param_mut]),
             ),
             # 8:
-            (
-                mutable_lin,
-                self.var,
-                _MutableLinearExpression([self.mon_bin, self.mon_var]),
-            ),
+            (mutable_lin, self.var, _MutableLinearExpression([self.bin, self.var])),
             (
                 mutable_lin,
                 self.mon_native,
-                _MutableLinearExpression([self.mon_bin, self.mon_native]),
+                _MutableLinearExpression([self.bin, self.mon_native]),
             ),
             (
                 mutable_lin,
                 self.mon_param,
-                _MutableLinearExpression([self.mon_bin, self.mon_param]),
+                _MutableLinearExpression([self.bin, self.mon_param]),
             ),
             (
                 mutable_lin,
                 self.mon_npv,
-                _MutableLinearExpression([self.mon_bin, self.mon_npv]),
+                _MutableLinearExpression([self.bin, self.mon_npv]),
             ),
             # 12:
             (
                 mutable_lin,
                 self.linear,
-                _MutableLinearExpression([self.mon_bin] + self.linear.args),
-            ),
-            (
-                mutable_lin,
-                self.sum,
-                _MutableSumExpression([self.mon_bin] + self.sum.args),
-            ),
-            (
-                mutable_lin,
-                self.other,
-                _MutableSumExpression([self.mon_bin, self.other]),
+                _MutableLinearExpression([self.bin] + self.linear.args),
             ),
-            (mutable_lin, self.mutable_l0, _MutableLinearExpression([self.mon_bin])),
+            (mutable_lin, self.sum, _MutableSumExpression([self.bin] + self.sum.args)),
+            (mutable_lin, self.other, _MutableSumExpression([self.bin, self.other])),
+            (mutable_lin, self.mutable_l0, _MutableLinearExpression([self.bin])),
             # 16:
             (
                 mutable_lin,
                 self.mutable_l1,
-                _MutableLinearExpression([self.mon_bin] + self.mutable_l1.args),
+                _MutableLinearExpression([self.bin] + self.mutable_l1.args),
             ),
             (
                 mutable_lin,
                 self.mutable_l2,
-                _MutableSumExpression([self.mon_bin] + self.mutable_l2.args),
+                _MutableSumExpression([self.bin] + self.mutable_l2.args),
             ),
-            (mutable_lin, self.param0, _MutableLinearExpression([self.mon_bin])),
-            (mutable_lin, self.param1, _MutableLinearExpression([self.mon_bin, 1])),
+            (mutable_lin, self.param0, _MutableLinearExpression([self.bin])),
+            (mutable_lin, self.param1, _MutableLinearExpression([self.bin, 1])),
             # 20:
             (
                 mutable_lin,
                 self.mutable_l3,
-                _MutableLinearExpression([self.mon_bin, self.npv]),
+                _MutableLinearExpression([self.bin, self.npv]),
             ),
         ]
         self._run_iadd_cases(tests, operator.iadd)
@@ -6854,7 +6784,7 @@ def as_numeric(self):
         assertExpressionsEqual(self, PowExpression((self.var, 2)), e)
 
         e = obj + obj
-        assertExpressionsEqual(self, LinearExpression((self.mon_var, self.mon_var)), e)
+        assertExpressionsEqual(self, LinearExpression((self.var, self.var)), e)
 
     def test_categorize_arg_type(self):
         class CustomAsNumeric(NumericValue):
diff --git a/pyomo/core/tests/unit/test_numeric_expr_zerofilter.py b/pyomo/core/tests/unit/test_numeric_expr_zerofilter.py
index 3000f644e80..19968640a21 100644
--- a/pyomo/core/tests/unit/test_numeric_expr_zerofilter.py
+++ b/pyomo/core/tests/unit/test_numeric_expr_zerofilter.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -102,38 +102,34 @@ def test_add_asbinary(self):
             # BooleanVar objects do not support addition
             (self.asbinary, self.asbinary, NotImplemented),
             (self.asbinary, self.zero, self.bin),
-            (self.asbinary, self.one, LinearExpression([self.mon_bin, 1])),
+            (self.asbinary, self.one, LinearExpression([self.bin, 1])),
             # 4:
-            (self.asbinary, self.native, LinearExpression([self.mon_bin, 5])),
-            (self.asbinary, self.npv, LinearExpression([self.mon_bin, self.npv])),
-            (self.asbinary, self.param, LinearExpression([self.mon_bin, 6])),
+            (self.asbinary, self.native, LinearExpression([self.bin, 5])),
+            (self.asbinary, self.npv, LinearExpression([self.bin, self.npv])),
+            (self.asbinary, self.param, LinearExpression([self.bin, 6])),
             (
                 self.asbinary,
                 self.param_mut,
-                LinearExpression([self.mon_bin, self.param_mut]),
+                LinearExpression([self.bin, self.param_mut]),
             ),
             # 8:
-            (self.asbinary, self.var, LinearExpression([self.mon_bin, self.mon_var])),
+            (self.asbinary, self.var, LinearExpression([self.bin, self.var])),
             (
                 self.asbinary,
                 self.mon_native,
-                LinearExpression([self.mon_bin, self.mon_native]),
+                LinearExpression([self.bin, self.mon_native]),
             ),
             (
                 self.asbinary,
                 self.mon_param,
-                LinearExpression([self.mon_bin, self.mon_param]),
-            ),
-            (
-                self.asbinary,
-                self.mon_npv,
-                LinearExpression([self.mon_bin, self.mon_npv]),
+                LinearExpression([self.bin, self.mon_param]),
             ),
+            (self.asbinary, self.mon_npv, LinearExpression([self.bin, self.mon_npv])),
             # 12:
             (
                 self.asbinary,
                 self.linear,
-                LinearExpression(self.linear.args + [self.mon_bin]),
+                LinearExpression(self.linear.args + [self.bin]),
             ),
             (self.asbinary, self.sum, SumExpression(self.sum.args + [self.bin])),
             (self.asbinary, self.other, SumExpression([self.bin, self.other])),
@@ -142,7 +138,7 @@ def test_add_asbinary(self):
             (
                 self.asbinary,
                 self.mutable_l1,
-                LinearExpression([self.mon_bin, self.mon_npv]),
+                LinearExpression([self.bin, self.mon_npv]),
             ),
             (
                 self.asbinary,
@@ -150,13 +146,9 @@ def test_add_asbinary(self):
                 SumExpression(self.mutable_l2.args + [self.bin]),
             ),
             (self.asbinary, self.param0, self.bin),
-            (self.asbinary, self.param1, LinearExpression([self.mon_bin, 1])),
+            (self.asbinary, self.param1, LinearExpression([self.bin, 1])),
             # 20:
-            (
-                self.asbinary,
-                self.mutable_l3,
-                LinearExpression([self.mon_bin, self.npv]),
-            ),
+            (self.asbinary, self.mutable_l3, LinearExpression([self.bin, self.npv])),
         ]
         self._run_cases(tests, operator.add)
         self._run_cases(tests, operator.iadd)
@@ -196,7 +188,7 @@ def test_add_zero(self):
     def test_add_one(self):
         tests = [
             (self.one, self.invalid, NotImplemented),
-            (self.one, self.asbinary, LinearExpression([1, self.mon_bin])),
+            (self.one, self.asbinary, LinearExpression([1, self.bin])),
             (self.one, self.zero, 1),
             (self.one, self.one, 2),
             # 4:
@@ -205,7 +197,7 @@ def test_add_one(self):
             (self.one, self.param, 7),
             (self.one, self.param_mut, NPV_SumExpression([1, self.param_mut])),
             # 8:
-            (self.one, self.var, LinearExpression([1, self.mon_var])),
+            (self.one, self.var, LinearExpression([1, self.var])),
             (self.one, self.mon_native, LinearExpression([1, self.mon_native])),
             (self.one, self.mon_param, LinearExpression([1, self.mon_param])),
             (self.one, self.mon_npv, LinearExpression([1, self.mon_npv])),
@@ -228,7 +220,7 @@ def test_add_one(self):
     def test_add_native(self):
         tests = [
             (self.native, self.invalid, NotImplemented),
-            (self.native, self.asbinary, LinearExpression([5, self.mon_bin])),
+            (self.native, self.asbinary, LinearExpression([5, self.bin])),
             (self.native, self.zero, 5),
             (self.native, self.one, 6),
             # 4:
@@ -237,7 +229,7 @@ def test_add_native(self):
             (self.native, self.param, 11),
             (self.native, self.param_mut, NPV_SumExpression([5, self.param_mut])),
             # 8:
-            (self.native, self.var, LinearExpression([5, self.mon_var])),
+            (self.native, self.var, LinearExpression([5, self.var])),
             (self.native, self.mon_native, LinearExpression([5, self.mon_native])),
             (self.native, self.mon_param, LinearExpression([5, self.mon_param])),
             (self.native, self.mon_npv, LinearExpression([5, self.mon_npv])),
@@ -264,7 +256,7 @@ def test_add_native(self):
     def test_add_npv(self):
         tests = [
             (self.npv, self.invalid, NotImplemented),
-            (self.npv, self.asbinary, LinearExpression([self.npv, self.mon_bin])),
+            (self.npv, self.asbinary, LinearExpression([self.npv, self.bin])),
             (self.npv, self.zero, self.npv),
             (self.npv, self.one, NPV_SumExpression([self.npv, 1])),
             # 4:
@@ -273,7 +265,7 @@ def test_add_npv(self):
             (self.npv, self.param, NPV_SumExpression([self.npv, 6])),
             (self.npv, self.param_mut, NPV_SumExpression([self.npv, self.param_mut])),
             # 8:
-            (self.npv, self.var, LinearExpression([self.npv, self.mon_var])),
+            (self.npv, self.var, LinearExpression([self.npv, self.var])),
             (self.npv, self.mon_native, LinearExpression([self.npv, self.mon_native])),
             (self.npv, self.mon_param, LinearExpression([self.npv, self.mon_param])),
             (self.npv, self.mon_npv, LinearExpression([self.npv, self.mon_npv])),
@@ -304,7 +296,7 @@ def test_add_npv(self):
     def test_add_param(self):
         tests = [
             (self.param, self.invalid, NotImplemented),
-            (self.param, self.asbinary, LinearExpression([6, self.mon_bin])),
+            (self.param, self.asbinary, LinearExpression([6, self.bin])),
             (self.param, self.zero, 6),
             (self.param, self.one, 7),
             # 4:
@@ -313,7 +305,7 @@ def test_add_param(self):
             (self.param, self.param, 12),
             (self.param, self.param_mut, NPV_SumExpression([6, self.param_mut])),
             # 8:
-            (self.param, self.var, LinearExpression([6, self.mon_var])),
+            (self.param, self.var, LinearExpression([6, self.var])),
             (self.param, self.mon_native, LinearExpression([6, self.mon_native])),
             (self.param, self.mon_param, LinearExpression([6, self.mon_param])),
             (self.param, self.mon_npv, LinearExpression([6, self.mon_npv])),
@@ -339,7 +331,7 @@ def test_add_param_mut(self):
             (
                 self.param_mut,
                 self.asbinary,
-                LinearExpression([self.param_mut, self.mon_bin]),
+                LinearExpression([self.param_mut, self.bin]),
             ),
             (self.param_mut, self.zero, self.param_mut),
             (self.param_mut, self.one, NPV_SumExpression([self.param_mut, 1])),
@@ -353,11 +345,7 @@ def test_add_param_mut(self):
                 NPV_SumExpression([self.param_mut, self.param_mut]),
             ),
             # 8:
-            (
-                self.param_mut,
-                self.var,
-                LinearExpression([self.param_mut, self.mon_var]),
-            ),
+            (self.param_mut, self.var, LinearExpression([self.param_mut, self.var])),
             (
                 self.param_mut,
                 self.mon_native,
@@ -408,37 +396,21 @@ def test_add_param_mut(self):
     def test_add_var(self):
         tests = [
             (self.var, self.invalid, NotImplemented),
-            (self.var, self.asbinary, LinearExpression([self.mon_var, self.mon_bin])),
+            (self.var, self.asbinary, LinearExpression([self.var, self.bin])),
             (self.var, self.zero, self.var),
-            (self.var, self.one, LinearExpression([self.mon_var, 1])),
+            (self.var, self.one, LinearExpression([self.var, 1])),
             # 4:
-            (self.var, self.native, LinearExpression([self.mon_var, 5])),
-            (self.var, self.npv, LinearExpression([self.mon_var, self.npv])),
-            (self.var, self.param, LinearExpression([self.mon_var, 6])),
-            (
-                self.var,
-                self.param_mut,
-                LinearExpression([self.mon_var, self.param_mut]),
-            ),
+            (self.var, self.native, LinearExpression([self.var, 5])),
+            (self.var, self.npv, LinearExpression([self.var, self.npv])),
+            (self.var, self.param, LinearExpression([self.var, 6])),
+            (self.var, self.param_mut, LinearExpression([self.var, self.param_mut])),
             # 8:
-            (self.var, self.var, LinearExpression([self.mon_var, self.mon_var])),
-            (
-                self.var,
-                self.mon_native,
-                LinearExpression([self.mon_var, self.mon_native]),
-            ),
-            (
-                self.var,
-                self.mon_param,
-                LinearExpression([self.mon_var, self.mon_param]),
-            ),
-            (self.var, self.mon_npv, LinearExpression([self.mon_var, self.mon_npv])),
+            (self.var, self.var, LinearExpression([self.var, self.var])),
+            (self.var, self.mon_native, LinearExpression([self.var, self.mon_native])),
+            (self.var, self.mon_param, LinearExpression([self.var, self.mon_param])),
+            (self.var, self.mon_npv, LinearExpression([self.var, self.mon_npv])),
             # 12:
-            (
-                self.var,
-                self.linear,
-                LinearExpression(self.linear.args + [self.mon_var]),
-            ),
+            (self.var, self.linear, LinearExpression(self.linear.args + [self.var])),
             (self.var, self.sum, SumExpression(self.sum.args + [self.var])),
             (self.var, self.other, SumExpression([self.var, self.other])),
             (self.var, self.mutable_l0, self.var),
@@ -446,7 +418,7 @@ def test_add_var(self):
             (
                 self.var,
                 self.mutable_l1,
-                LinearExpression([self.mon_var] + self.mutable_l1.args),
+                LinearExpression([self.var] + self.mutable_l1.args),
             ),
             (
                 self.var,
@@ -454,13 +426,9 @@ def test_add_var(self):
                 SumExpression(self.mutable_l2.args + [self.var]),
             ),
             (self.var, self.param0, self.var),
-            (self.var, self.param1, LinearExpression([self.mon_var, 1])),
+            (self.var, self.param1, LinearExpression([self.var, 1])),
             # 20:
-            (
-                self.var,
-                self.mutable_l3,
-                LinearExpression([MonomialTermExpression((1, self.var)), self.npv]),
-            ),
+            (self.var, self.mutable_l3, LinearExpression([self.var, self.npv])),
         ]
         self._run_cases(tests, operator.add)
         self._run_cases(tests, operator.iadd)
@@ -471,7 +439,7 @@ def test_add_mon_native(self):
             (
                 self.mon_native,
                 self.asbinary,
-                LinearExpression([self.mon_native, self.mon_bin]),
+                LinearExpression([self.mon_native, self.bin]),
             ),
             (self.mon_native, self.zero, self.mon_native),
             (self.mon_native, self.one, LinearExpression([self.mon_native, 1])),
@@ -485,11 +453,7 @@ def test_add_mon_native(self):
                 LinearExpression([self.mon_native, self.param_mut]),
             ),
             # 8:
-            (
-                self.mon_native,
-                self.var,
-                LinearExpression([self.mon_native, self.mon_var]),
-            ),
+            (self.mon_native, self.var, LinearExpression([self.mon_native, self.var])),
             (
                 self.mon_native,
                 self.mon_native,
@@ -547,7 +511,7 @@ def test_add_mon_param(self):
             (
                 self.mon_param,
                 self.asbinary,
-                LinearExpression([self.mon_param, self.mon_bin]),
+                LinearExpression([self.mon_param, self.bin]),
             ),
             (self.mon_param, self.zero, self.mon_param),
             (self.mon_param, self.one, LinearExpression([self.mon_param, 1])),
@@ -561,11 +525,7 @@ def test_add_mon_param(self):
                 LinearExpression([self.mon_param, self.param_mut]),
             ),
             # 8:
-            (
-                self.mon_param,
-                self.var,
-                LinearExpression([self.mon_param, self.mon_var]),
-            ),
+            (self.mon_param, self.var, LinearExpression([self.mon_param, self.var])),
             (
                 self.mon_param,
                 self.mon_native,
@@ -616,11 +576,7 @@ def test_add_mon_param(self):
     def test_add_mon_npv(self):
         tests = [
             (self.mon_npv, self.invalid, NotImplemented),
-            (
-                self.mon_npv,
-                self.asbinary,
-                LinearExpression([self.mon_npv, self.mon_bin]),
-            ),
+            (self.mon_npv, self.asbinary, LinearExpression([self.mon_npv, self.bin])),
             (self.mon_npv, self.zero, self.mon_npv),
             (self.mon_npv, self.one, LinearExpression([self.mon_npv, 1])),
             # 4:
@@ -633,7 +589,7 @@ def test_add_mon_npv(self):
                 LinearExpression([self.mon_npv, self.param_mut]),
             ),
             # 8:
-            (self.mon_npv, self.var, LinearExpression([self.mon_npv, self.mon_var])),
+            (self.mon_npv, self.var, LinearExpression([self.mon_npv, self.var])),
             (
                 self.mon_npv,
                 self.mon_native,
@@ -683,7 +639,7 @@ def test_add_linear(self):
             (
                 self.linear,
                 self.asbinary,
-                LinearExpression(self.linear.args + [self.mon_bin]),
+                LinearExpression(self.linear.args + [self.bin]),
             ),
             (self.linear, self.zero, self.linear),
             (self.linear, self.one, LinearExpression(self.linear.args + [1])),
@@ -697,11 +653,7 @@ def test_add_linear(self):
                 LinearExpression(self.linear.args + [self.param_mut]),
             ),
             # 8:
-            (
-                self.linear,
-                self.var,
-                LinearExpression(self.linear.args + [self.mon_var]),
-            ),
+            (self.linear, self.var, LinearExpression(self.linear.args + [self.var])),
             (
                 self.linear,
                 self.mon_native,
@@ -868,7 +820,7 @@ def test_add_mutable_l1(self):
             (
                 self.mutable_l1,
                 self.asbinary,
-                LinearExpression(self.mutable_l1.args + [self.mon_bin]),
+                LinearExpression(self.mutable_l1.args + [self.bin]),
             ),
             (self.mutable_l1, self.zero, self.mon_npv),
             (self.mutable_l1, self.one, LinearExpression(self.mutable_l1.args + [1])),
@@ -893,7 +845,7 @@ def test_add_mutable_l1(self):
             (
                 self.mutable_l1,
                 self.var,
-                LinearExpression(self.mutable_l1.args + [self.mon_var]),
+                LinearExpression(self.mutable_l1.args + [self.var]),
             ),
             (
                 self.mutable_l1,
@@ -1075,7 +1027,7 @@ def test_add_param0(self):
     def test_add_param1(self):
         tests = [
             (self.param1, self.invalid, NotImplemented),
-            (self.param1, self.asbinary, LinearExpression([1, self.mon_bin])),
+            (self.param1, self.asbinary, LinearExpression([1, self.bin])),
             (self.param1, self.zero, 1),
             (self.param1, self.one, 2),
             # 4:
@@ -1084,7 +1036,7 @@ def test_add_param1(self):
             (self.param1, self.param, 7),
             (self.param1, self.param_mut, NPV_SumExpression([1, self.param_mut])),
             # 8:
-            (self.param1, self.var, LinearExpression([1, self.mon_var])),
+            (self.param1, self.var, LinearExpression([1, self.var])),
             (self.param1, self.mon_native, LinearExpression([1, self.mon_native])),
             (self.param1, self.mon_param, LinearExpression([1, self.mon_param])),
             (self.param1, self.mon_npv, LinearExpression([1, self.mon_npv])),
@@ -1114,7 +1066,7 @@ def test_add_mutable_l3(self):
             (
                 self.mutable_l3,
                 self.asbinary,
-                LinearExpression(self.mutable_l3.args + [self.mon_bin]),
+                LinearExpression(self.mutable_l3.args + [self.bin]),
             ),
             (self.mutable_l3, self.zero, self.npv),
             (self.mutable_l3, self.one, NPV_SumExpression(self.mutable_l3.args + [1])),
@@ -1143,7 +1095,7 @@ def test_add_mutable_l3(self):
             (
                 self.mutable_l3,
                 self.var,
-                LinearExpression(self.mutable_l3.args + [self.mon_var]),
+                LinearExpression(self.mutable_l3.args + [self.var]),
             ),
             (
                 self.mutable_l3,
@@ -1249,32 +1201,32 @@ def test_sub_asbinary(self):
             # BooleanVar objects do not support addition
             (self.asbinary, self.asbinary, NotImplemented),
             (self.asbinary, self.zero, self.bin),
-            (self.asbinary, self.one, LinearExpression([self.mon_bin, -1])),
+            (self.asbinary, self.one, LinearExpression([self.bin, -1])),
             # 4:
-            (self.asbinary, self.native, LinearExpression([self.mon_bin, -5])),
-            (self.asbinary, self.npv, LinearExpression([self.mon_bin, self.minus_npv])),
-            (self.asbinary, self.param, LinearExpression([self.mon_bin, -6])),
+            (self.asbinary, self.native, LinearExpression([self.bin, -5])),
+            (self.asbinary, self.npv, LinearExpression([self.bin, self.minus_npv])),
+            (self.asbinary, self.param, LinearExpression([self.bin, -6])),
             (
                 self.asbinary,
                 self.param_mut,
-                LinearExpression([self.mon_bin, self.minus_param_mut]),
+                LinearExpression([self.bin, self.minus_param_mut]),
             ),
             # 8:
-            (self.asbinary, self.var, LinearExpression([self.mon_bin, self.minus_var])),
+            (self.asbinary, self.var, LinearExpression([self.bin, self.minus_var])),
             (
                 self.asbinary,
                 self.mon_native,
-                LinearExpression([self.mon_bin, self.minus_mon_native]),
+                LinearExpression([self.bin, self.minus_mon_native]),
             ),
             (
                 self.asbinary,
                 self.mon_param,
-                LinearExpression([self.mon_bin, self.minus_mon_param]),
+                LinearExpression([self.bin, self.minus_mon_param]),
             ),
             (
                 self.asbinary,
                 self.mon_npv,
-                LinearExpression([self.mon_bin, self.minus_mon_npv]),
+                LinearExpression([self.bin, self.minus_mon_npv]),
             ),
             # 12:
             (self.asbinary, self.linear, SumExpression([self.bin, self.minus_linear])),
@@ -1285,7 +1237,7 @@ def test_sub_asbinary(self):
             (
                 self.asbinary,
                 self.mutable_l1,
-                LinearExpression([self.mon_bin, self.minus_mon_npv]),
+                LinearExpression([self.bin, self.minus_mon_npv]),
             ),
             (
                 self.asbinary,
@@ -1293,12 +1245,12 @@ def test_sub_asbinary(self):
                 SumExpression([self.bin, self.minus_mutable_l2]),
             ),
             (self.asbinary, self.param0, self.bin),
-            (self.asbinary, self.param1, LinearExpression([self.mon_bin, -1])),
+            (self.asbinary, self.param1, LinearExpression([self.bin, -1])),
             # 20:
             (
                 self.asbinary,
                 self.mutable_l3,
-                LinearExpression([self.mon_bin, self.minus_npv]),
+                LinearExpression([self.bin, self.minus_npv]),
             ),
         ]
         self._run_cases(tests, operator.sub)
@@ -1571,35 +1523,31 @@ def test_sub_param_mut(self):
     def test_sub_var(self):
         tests = [
             (self.var, self.invalid, NotImplemented),
-            (self.var, self.asbinary, LinearExpression([self.mon_var, self.minus_bin])),
+            (self.var, self.asbinary, LinearExpression([self.var, self.minus_bin])),
             (self.var, self.zero, self.var),
-            (self.var, self.one, LinearExpression([self.mon_var, -1])),
+            (self.var, self.one, LinearExpression([self.var, -1])),
             # 4:
-            (self.var, self.native, LinearExpression([self.mon_var, -5])),
-            (self.var, self.npv, LinearExpression([self.mon_var, self.minus_npv])),
-            (self.var, self.param, LinearExpression([self.mon_var, -6])),
+            (self.var, self.native, LinearExpression([self.var, -5])),
+            (self.var, self.npv, LinearExpression([self.var, self.minus_npv])),
+            (self.var, self.param, LinearExpression([self.var, -6])),
             (
                 self.var,
                 self.param_mut,
-                LinearExpression([self.mon_var, self.minus_param_mut]),
+                LinearExpression([self.var, self.minus_param_mut]),
             ),
             # 8:
-            (self.var, self.var, LinearExpression([self.mon_var, self.minus_var])),
+            (self.var, self.var, LinearExpression([self.var, self.minus_var])),
             (
                 self.var,
                 self.mon_native,
-                LinearExpression([self.mon_var, self.minus_mon_native]),
+                LinearExpression([self.var, self.minus_mon_native]),
             ),
             (
                 self.var,
                 self.mon_param,
-                LinearExpression([self.mon_var, self.minus_mon_param]),
-            ),
-            (
-                self.var,
-                self.mon_npv,
-                LinearExpression([self.mon_var, self.minus_mon_npv]),
+                LinearExpression([self.var, self.minus_mon_param]),
             ),
+            (self.var, self.mon_npv, LinearExpression([self.var, self.minus_mon_npv])),
             # 12:
             (
                 self.var,
@@ -1613,7 +1561,7 @@ def test_sub_var(self):
             (
                 self.var,
                 self.mutable_l1,
-                LinearExpression([self.mon_var, self.minus_mon_npv]),
+                LinearExpression([self.var, self.minus_mon_npv]),
             ),
             (
                 self.var,
@@ -1621,13 +1569,9 @@ def test_sub_var(self):
                 SumExpression([self.var, self.minus_mutable_l2]),
             ),
             (self.var, self.param0, self.var),
-            (self.var, self.param1, LinearExpression([self.mon_var, -1])),
+            (self.var, self.param1, LinearExpression([self.var, -1])),
             # 20:
-            (
-                self.var,
-                self.mutable_l3,
-                LinearExpression([self.mon_var, self.minus_npv]),
-            ),
+            (self.var, self.mutable_l3, LinearExpression([self.var, self.minus_npv])),
         ]
         self._run_cases(tests, operator.sub)
         self._run_cases(tests, operator.isub)
@@ -6039,7 +5983,7 @@ def test_mutable_nvp_iadd(self):
         mutable_npv = _MutableNPVSumExpression([])
         tests = [
             (mutable_npv, self.invalid, NotImplemented),
-            (mutable_npv, self.asbinary, _MutableLinearExpression([self.mon_bin])),
+            (mutable_npv, self.asbinary, _MutableLinearExpression([self.bin])),
             (mutable_npv, self.zero, _MutableNPVSumExpression([])),
             (mutable_npv, self.one, _MutableNPVSumExpression([1])),
             # 4:
@@ -6048,7 +5992,7 @@ def test_mutable_nvp_iadd(self):
             (mutable_npv, self.param, _MutableNPVSumExpression([6])),
             (mutable_npv, self.param_mut, _MutableNPVSumExpression([self.param_mut])),
             # 8:
-            (mutable_npv, self.var, _MutableLinearExpression([self.mon_var])),
+            (mutable_npv, self.var, _MutableLinearExpression([self.var])),
             (mutable_npv, self.mon_native, _MutableLinearExpression([self.mon_native])),
             (mutable_npv, self.mon_param, _MutableLinearExpression([self.mon_param])),
             (mutable_npv, self.mon_npv, _MutableLinearExpression([self.mon_npv])),
@@ -6074,20 +6018,20 @@ def test_mutable_nvp_iadd(self):
         mutable_npv = _MutableNPVSumExpression([10])
         tests = [
             (mutable_npv, self.invalid, NotImplemented),
-            (mutable_npv, self.asbinary, _MutableLinearExpression([10, self.mon_bin])),
+            (mutable_npv, self.asbinary, _MutableLinearExpression([10, self.bin])),
             (mutable_npv, self.zero, _MutableNPVSumExpression([10])),
-            (mutable_npv, self.one, _MutableNPVSumExpression([10, 1])),
+            (mutable_npv, self.one, _MutableNPVSumExpression([11])),
             # 4:
-            (mutable_npv, self.native, _MutableNPVSumExpression([10, 5])),
+            (mutable_npv, self.native, _MutableNPVSumExpression([15])),
             (mutable_npv, self.npv, _MutableNPVSumExpression([10, self.npv])),
-            (mutable_npv, self.param, _MutableNPVSumExpression([10, 6])),
+            (mutable_npv, self.param, _MutableNPVSumExpression([16])),
             (
                 mutable_npv,
                 self.param_mut,
                 _MutableNPVSumExpression([10, self.param_mut]),
             ),
             # 8:
-            (mutable_npv, self.var, _MutableLinearExpression([10, self.mon_var])),
+            (mutable_npv, self.var, _MutableLinearExpression([10, self.var])),
             (
                 mutable_npv,
                 self.mon_native,
@@ -6120,7 +6064,7 @@ def test_mutable_nvp_iadd(self):
                 _MutableSumExpression([10] + self.mutable_l2.args),
             ),
             (mutable_npv, self.param0, _MutableNPVSumExpression([10])),
-            (mutable_npv, self.param1, _MutableNPVSumExpression([10, 1])),
+            (mutable_npv, self.param1, _MutableNPVSumExpression([11])),
             # 20:
             (mutable_npv, self.mutable_l3, _MutableNPVSumExpression([10, self.npv])),
         ]
@@ -6130,7 +6074,7 @@ def test_mutable_lin_iadd(self):
         mutable_lin = _MutableLinearExpression([])
         tests = [
             (mutable_lin, self.invalid, NotImplemented),
-            (mutable_lin, self.asbinary, _MutableLinearExpression([self.mon_bin])),
+            (mutable_lin, self.asbinary, _MutableLinearExpression([self.bin])),
             (mutable_lin, self.zero, _MutableLinearExpression([])),
             (mutable_lin, self.one, _MutableLinearExpression([1])),
             # 4:
@@ -6139,7 +6083,7 @@ def test_mutable_lin_iadd(self):
             (mutable_lin, self.param, _MutableLinearExpression([6])),
             (mutable_lin, self.param_mut, _MutableLinearExpression([self.param_mut])),
             # 8:
-            (mutable_lin, self.var, _MutableLinearExpression([self.mon_var])),
+            (mutable_lin, self.var, _MutableLinearExpression([self.var])),
             (mutable_lin, self.mon_native, _MutableLinearExpression([self.mon_native])),
             (mutable_lin, self.mon_param, _MutableLinearExpression([self.mon_param])),
             (mutable_lin, self.mon_npv, _MutableLinearExpression([self.mon_npv])),
@@ -6162,81 +6106,69 @@ def test_mutable_lin_iadd(self):
         ]
         self._run_iadd_cases(tests, operator.iadd)
 
-        mutable_lin = _MutableLinearExpression([self.mon_bin])
+        mutable_lin = _MutableLinearExpression([self.bin])
         tests = [
             (mutable_lin, self.invalid, NotImplemented),
             (
                 mutable_lin,
                 self.asbinary,
-                _MutableLinearExpression([self.mon_bin, self.mon_bin]),
+                _MutableLinearExpression([self.bin, self.bin]),
             ),
-            (mutable_lin, self.zero, _MutableLinearExpression([self.mon_bin])),
-            (mutable_lin, self.one, _MutableLinearExpression([self.mon_bin, 1])),
+            (mutable_lin, self.zero, _MutableLinearExpression([self.bin])),
+            (mutable_lin, self.one, _MutableLinearExpression([self.bin, 1])),
             # 4:
-            (mutable_lin, self.native, _MutableLinearExpression([self.mon_bin, 5])),
-            (mutable_lin, self.npv, _MutableLinearExpression([self.mon_bin, self.npv])),
-            (mutable_lin, self.param, _MutableLinearExpression([self.mon_bin, 6])),
+            (mutable_lin, self.native, _MutableLinearExpression([self.bin, 5])),
+            (mutable_lin, self.npv, _MutableLinearExpression([self.bin, self.npv])),
+            (mutable_lin, self.param, _MutableLinearExpression([self.bin, 6])),
             (
                 mutable_lin,
                 self.param_mut,
-                _MutableLinearExpression([self.mon_bin, self.param_mut]),
+                _MutableLinearExpression([self.bin, self.param_mut]),
             ),
             # 8:
-            (
-                mutable_lin,
-                self.var,
-                _MutableLinearExpression([self.mon_bin, self.mon_var]),
-            ),
+            (mutable_lin, self.var, _MutableLinearExpression([self.bin, self.var])),
             (
                 mutable_lin,
                 self.mon_native,
-                _MutableLinearExpression([self.mon_bin, self.mon_native]),
+                _MutableLinearExpression([self.bin, self.mon_native]),
             ),
             (
                 mutable_lin,
                 self.mon_param,
-                _MutableLinearExpression([self.mon_bin, self.mon_param]),
+                _MutableLinearExpression([self.bin, self.mon_param]),
             ),
             (
                 mutable_lin,
                 self.mon_npv,
-                _MutableLinearExpression([self.mon_bin, self.mon_npv]),
+                _MutableLinearExpression([self.bin, self.mon_npv]),
             ),
             # 12:
             (
                 mutable_lin,
                 self.linear,
-                _MutableLinearExpression([self.mon_bin] + self.linear.args),
-            ),
-            (
-                mutable_lin,
-                self.sum,
-                _MutableSumExpression([self.mon_bin] + self.sum.args),
-            ),
-            (
-                mutable_lin,
-                self.other,
-                _MutableSumExpression([self.mon_bin, self.other]),
+                _MutableLinearExpression([self.bin] + self.linear.args),
             ),
-            (mutable_lin, self.mutable_l0, _MutableLinearExpression([self.mon_bin])),
+            (mutable_lin, self.sum, _MutableSumExpression([self.bin] + self.sum.args)),
+            (mutable_lin, self.other, _MutableSumExpression([self.bin, self.other])),
+            (mutable_lin, self.mutable_l0, _MutableLinearExpression([self.bin])),
             # 16:
             (
                 mutable_lin,
                 self.mutable_l1,
-                _MutableLinearExpression([self.mon_bin] + self.mutable_l1.args),
+                _MutableLinearExpression([self.bin] + self.mutable_l1.args),
             ),
             (
                 mutable_lin,
                 self.mutable_l2,
-                _MutableSumExpression([self.mon_bin] + self.mutable_l2.args),
+                _MutableSumExpression([self.bin] + self.mutable_l2.args),
             ),
-            (mutable_lin, self.param0, _MutableLinearExpression([self.mon_bin])),
-            (mutable_lin, self.param1, _MutableLinearExpression([self.mon_bin, 1])),
+            (mutable_lin, self.param0, _MutableLinearExpression([self.bin])),
+            (mutable_lin, self.param1, _MutableLinearExpression([self.bin, 1])),
             # 20:
             (
                 mutable_lin,
                 self.mutable_l3,
-                _MutableLinearExpression([self.mon_bin, self.npv]),
+                _MutableLinearExpression([self.bin, self.npv]),
             ),
         ]
         self._run_iadd_cases(tests, operator.iadd)
diff --git a/pyomo/core/tests/unit/test_numpy_expr.py b/pyomo/core/tests/unit/test_numpy_expr.py
index 8f58eb29e56..fb81dfe809f 100644
--- a/pyomo/core/tests/unit/test_numpy_expr.py
+++ b/pyomo/core/tests/unit/test_numpy_expr.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_numvalue.py b/pyomo/core/tests/unit/test_numvalue.py
index 74df1d29522..4d39a42ed70 100644
--- a/pyomo/core/tests/unit/test_numvalue.py
+++ b/pyomo/core/tests/unit/test_numvalue.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -18,6 +18,7 @@
 
 import pyomo.common.unittest as unittest
 from pyomo.common.dependencies import numpy, numpy_available
+from pyomo.core.base.units_container import pint_available
 
 from pyomo.environ import (
     value,
@@ -50,7 +51,16 @@ def __init__(self, val=0):
 
 class MyBogusNumericType(MyBogusType):
     def __add__(self, other):
-        return MyBogusNumericType(self.val + float(other))
+        if other.__class__ in native_numeric_types:
+            return MyBogusNumericType(self.val + float(other))
+        else:
+            return NotImplemented
+
+    def __le__(self, other):
+        if other.__class__ in native_numeric_types:
+            return self.val <= float(other)
+        else:
+            return NotImplemented
 
     def __lt__(self, other):
         return self.val < float(other)
@@ -534,16 +544,18 @@ def test_unknownNumericType(self):
         try:
             val = as_numeric(ref)
             self.assertEqual(val().val, 42.0)
+            self.assertIn(MyBogusNumericType, native_numeric_types)
+            self.assertIn(MyBogusNumericType, native_types)
         finally:
             native_numeric_types.remove(MyBogusNumericType)
             native_types.remove(MyBogusNumericType)
 
     @unittest.skipUnless(numpy_available, "This test requires NumPy")
     def test_numpy_basic_float_registration(self):
-        self.assertIn(numpy.float_, native_numeric_types)
-        self.assertNotIn(numpy.float_, native_integer_types)
-        self.assertIn(numpy.float_, _native_boolean_types)
-        self.assertIn(numpy.float_, native_types)
+        self.assertIn(numpy.float64, native_numeric_types)
+        self.assertNotIn(numpy.float64, native_integer_types)
+        self.assertIn(numpy.float64, _native_boolean_types)
+        self.assertIn(numpy.float64, native_types)
 
     @unittest.skipUnless(numpy_available, "This test requires NumPy")
     def test_numpy_basic_int_registration(self):
@@ -562,9 +574,43 @@ def test_numpy_basic_bool_registration(self):
     @unittest.skipUnless(numpy_available, "This test requires NumPy")
     def test_automatic_numpy_registration(self):
         cmd = (
-            'import pyomo; from pyomo.core.base import Var, Param; import numpy as np; '
-            'print(np.float64 in pyomo.common.numeric_types.native_numeric_types); '
-            '%s; print(np.float64 in pyomo.common.numeric_types.native_numeric_types)'
+            'from pyomo.common.numeric_types import native_numeric_types as nnt; '
+            'print("float64" in [_.__name__ for _ in nnt]); '
+            'import numpy; '
+            'print("float64" in [_.__name__ for _ in nnt])'
+        )
+
+        rc = subprocess.run(
+            [sys.executable, '-c', cmd],
+            stdout=subprocess.PIPE,
+            stderr=subprocess.STDOUT,
+            text=True,
+        )
+        self.assertEqual((rc.returncode, rc.stdout), (0, "False\nTrue\n"))
+
+        cmd = (
+            'import numpy; '
+            'from pyomo.common.numeric_types import native_numeric_types as nnt; '
+            'print("float64" in [_.__name__ for _ in nnt])'
+        )
+
+        rc = subprocess.run(
+            [sys.executable, '-c', cmd],
+            stdout=subprocess.PIPE,
+            stderr=subprocess.STDOUT,
+            text=True,
+        )
+        self.assertEqual((rc.returncode, rc.stdout), (0, "True\n"))
+
+    def test_unknownNumericType_expr_registration(self):
+        cmd = (
+            'import pyomo; '
+            'from pyomo.core.base import Var, Param; '
+            'from pyomo.core.base.units_container import units; '
+            'from pyomo.common.numeric_types import native_numeric_types as nnt; '
+            f'from {__name__} import MyBogusNumericType; '
+            'ref = MyBogusNumericType(42); '
+            'print(MyBogusNumericType in nnt); %s; print(MyBogusNumericType in nnt); '
         )
 
         def _tester(expr):
@@ -574,14 +620,32 @@ def _tester(expr):
                 stderr=subprocess.STDOUT,
                 text=True,
             )
-            self.assertEqual((rc.returncode, rc.stdout), (0, "False\nTrue\n"))
-
-        _tester('Var() <= np.float64(5)')
-        _tester('np.float64(5) <= Var()')
-        _tester('np.float64(5) + Var()')
-        _tester('Var() + np.float64(5)')
-        _tester('v = Var(); v.construct(); v.value = np.float64(5)')
-        _tester('p = Param(mutable=True); p.construct(); p.value = np.float64(5)')
+            self.assertEqual(
+                (rc.returncode, rc.stdout),
+                (
+                    0,
+                    '''False
+WARNING: Dynamically registering the following numeric type:
+        pyomo.core.tests.unit.test_numvalue.MyBogusNumericType
+    Dynamic registration is supported for convenience, but there are known
+    limitations to this approach.  We recommend explicitly registering numeric
+    types using RegisterNumericType() or RegisterIntegerType().
+True
+''',
+                ),
+            )
+
+        _tester('Var() <= ref')
+        _tester('ref <= Var()')
+        _tester('ref + Var()')
+        _tester('Var() + ref')
+        _tester('v = Var(); v.construct(); v.value = ref')
+        _tester('p = Param(mutable=True); p.construct(); p.value = ref')
+        if pint_available:
+            _tester('v = Var(units=units.m); v.construct(); v.value = ref')
+            _tester(
+                'p = Param(mutable=True, units=units.m); p.construct(); p.value = ref'
+            )
 
 
 if __name__ == "__main__":
diff --git a/pyomo/core/tests/unit/test_obj.py b/pyomo/core/tests/unit/test_obj.py
index d73bf7d6dfd..dc2e320e63b 100644
--- a/pyomo/core/tests/unit/test_obj.py
+++ b/pyomo/core/tests/unit/test_obj.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -78,7 +78,7 @@ def test_empty_singleton(self):
         # Even though we construct a ScalarObjective,
         # if it is not initialized that means it is "empty"
         # and we should encounter errors when trying to access the
-        # _ObjectiveData interface methods until we assign
+        # ObjectiveData interface methods until we assign
         # something to the objective.
         #
         self.assertEqual(a._constructed, True)
diff --git a/pyomo/core/tests/unit/test_param.py b/pyomo/core/tests/unit/test_param.py
index 6ba1163e3c3..f22674b6bf7 100644
--- a/pyomo/core/tests/unit/test_param.py
+++ b/pyomo/core/tests/unit/test_param.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -65,8 +65,8 @@
 from pyomo.common.errors import PyomoException
 from pyomo.common.log import LoggingIntercept
 from pyomo.common.tempfiles import TempfileManager
-from pyomo.core.base.param import _ParamData
-from pyomo.core.base.set import _SetData
+from pyomo.core.base.param import ParamData
+from pyomo.core.base.set import SetData
 from pyomo.core.base.units_container import units, pint_available, UnitsError
 
 from io import StringIO
@@ -181,7 +181,7 @@ def test_setitem_preexisting(self):
         idx = sorted(keys)[0]
         self.assertEqual(value(self.instance.A[idx]), self.data[idx])
         if self.instance.A.mutable:
-            self.assertTrue(isinstance(self.instance.A[idx], _ParamData))
+            self.assertTrue(isinstance(self.instance.A[idx], ParamData))
         else:
             self.assertEqual(type(self.instance.A[idx]), float)
 
@@ -190,7 +190,7 @@ def test_setitem_preexisting(self):
             if not self.instance.A.mutable:
                 self.fail("Expected setitem[%s] to fail for immutable Params" % (idx,))
             self.assertEqual(value(self.instance.A[idx]), 4.3)
-            self.assertTrue(isinstance(self.instance.A[idx], _ParamData))
+            self.assertTrue(isinstance(self.instance.A[idx], ParamData))
         except TypeError:
             # immutable Params should raise a TypeError exception
             if self.instance.A.mutable:
@@ -249,7 +249,7 @@ def test_setitem_default_override(self):
 
         self.assertEqual(value(self.instance.A[idx]), self.instance.A._default_val)
         if self.instance.A.mutable:
-            self.assertIsInstance(self.instance.A[idx], _ParamData)
+            self.assertIsInstance(self.instance.A[idx], ParamData)
         else:
             self.assertEqual(
                 type(self.instance.A[idx]), type(value(self.instance.A._default_val))
@@ -260,7 +260,7 @@ def test_setitem_default_override(self):
             if not self.instance.A.mutable:
                 self.fail("Expected setitem[%s] to fail for immutable Params" % (idx,))
             self.assertEqual(self.instance.A[idx].value, 4.3)
-            self.assertIsInstance(self.instance.A[idx], _ParamData)
+            self.assertIsInstance(self.instance.A[idx], ParamData)
         except TypeError:
             # immutable Params should raise a TypeError exception
             if self.instance.A.mutable:
@@ -1487,7 +1487,7 @@ def test_domain_set_initializer(self):
         m.I = Set(initialize=[1, 2, 3])
         param_vals = {1: 1, 2: 1, 3: -1}
         m.p = Param(m.I, initialize=param_vals, domain={-1, 1})
-        self.assertIsInstance(m.p.domain, _SetData)
+        self.assertIsInstance(m.p.domain, SetData)
 
     @unittest.skipUnless(pint_available, "units test requires pint module")
     def test_set_value_units(self):
diff --git a/pyomo/core/tests/unit/test_pickle.py b/pyomo/core/tests/unit/test_pickle.py
index 861704a2f9c..fccc92bbfa2 100644
--- a/pyomo/core/tests/unit/test_pickle.py
+++ b/pyomo/core/tests/unit/test_pickle.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_piecewise.py b/pyomo/core/tests/unit/test_piecewise.py
index aeb02b82624..7b8e01e6a45 100644
--- a/pyomo/core/tests/unit/test_piecewise.py
+++ b/pyomo/core/tests/unit/test_piecewise.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -104,7 +104,7 @@ def test_indexed_with_nonindexed_vars(self):
         model.con3 = Piecewise(*args, **keywords)
 
     # test that nonindexed Piecewise can handle
-    # _VarData (e.g model.x[1]
+    # VarData (e.g model.x[1]
     def test_nonindexed_with_indexed_vars(self):
         model = ConcreteModel()
         model.range = Var([1])
diff --git a/pyomo/core/tests/unit/test_preprocess.py b/pyomo/core/tests/unit/test_preprocess.py
index d4c5ae75bb0..ce7924f3ac5 100644
--- a/pyomo/core/tests/unit/test_preprocess.py
+++ b/pyomo/core/tests/unit/test_preprocess.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_range.py b/pyomo/core/tests/unit/test_range.py
index 8cd1e7ce46c..4b489f50d44 100644
--- a/pyomo/core/tests/unit/test_range.py
+++ b/pyomo/core/tests/unit/test_range.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_reference.py b/pyomo/core/tests/unit/test_reference.py
index a7a470b1a3b..7370881612f 100644
--- a/pyomo/core/tests/unit/test_reference.py
+++ b/pyomo/core/tests/unit/test_reference.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -729,7 +729,6 @@ def test_component_data_reference(self):
 
         self.assertIs(m.r.ctype, Var)
         self.assertIsNot(m.r.index_set(), m.y.index_set())
-        self.assertIs(m.y.index_set(), m.y_index)
         self.assertIs(m.r.index_set(), UnindexedComponent_ReferenceSet)
         self.assertEqual(len(m.r), 1)
         self.assertTrue(m.r.is_reference())
@@ -773,7 +772,7 @@ def test_reference_var_pprint(self):
         m.r.pprint(ostream=buf)
         self.assertEqual(
             buf.getvalue(),
-            """r : Size=2, Index=x_index, ReferenceTo=x
+            """r : Size=2, Index={1, 2}, ReferenceTo=x
     Key : Lower : Value : Upper : Fixed : Stale : Domain
       1 :  None :     4 :  None : False : False :  Reals
       2 :  None :     8 :  None : False : False :  Reals
@@ -784,7 +783,7 @@ def test_reference_var_pprint(self):
         m.s.pprint(ostream=buf)
         self.assertEqual(
             buf.getvalue(),
-            """s : Size=2, Index=x_index, ReferenceTo=x[:, ...]
+            """s : Size=2, Index={1, 2}, ReferenceTo=x[:, ...]
     Key : Lower : Value : Upper : Fixed : Stale : Domain
       1 :  None :     4 :  None : False : False :  Reals
       2 :  None :     8 :  None : False : False :  Reals
@@ -799,10 +798,10 @@ def test_reference_indexedcomponent_pprint(self):
         m.r.pprint(ostream=buf)
         self.assertEqual(
             buf.getvalue(),
-            """r : Size=2, Index=x_index, ReferenceTo=x
+            """r : Size=2, Index={1, 2}, ReferenceTo=x
     Key : Object
-      1 : <class 'pyomo.core.base.var._GeneralVarData'>
-      2 : <class 'pyomo.core.base.var._GeneralVarData'>
+      1 : <class 'pyomo.core.base.var.VarData'>
+      2 : <class 'pyomo.core.base.var.VarData'>
 """,
         )
         m.s = Reference(m.x[:, ...], ctype=IndexedComponent)
@@ -810,10 +809,10 @@ def test_reference_indexedcomponent_pprint(self):
         m.s.pprint(ostream=buf)
         self.assertEqual(
             buf.getvalue(),
-            """s : Size=2, Index=x_index, ReferenceTo=x[:, ...]
+            """s : Size=2, Index={1, 2}, ReferenceTo=x[:, ...]
     Key : Object
-      1 : <class 'pyomo.core.base.var._GeneralVarData'>
-      2 : <class 'pyomo.core.base.var._GeneralVarData'>
+      1 : <class 'pyomo.core.base.var.VarData'>
+      2 : <class 'pyomo.core.base.var.VarData'>
 """,
         )
 
@@ -1281,7 +1280,6 @@ def test_contains_with_nonflattened(self):
             normalize_index.flatten = _old_flatten
 
     def test_pprint_nonfinite_sets(self):
-        self.maxDiff = None
         m = ConcreteModel()
         m.v = Var(NonNegativeIntegers, dense=False)
         m.ref = Reference(m.v)
@@ -1323,7 +1321,6 @@ def test_pprint_nonfinite_sets(self):
 
     def test_pprint_nonfinite_sets_ctypeNone(self):
         # test issue #2039
-        self.maxDiff = None
         m = ConcreteModel()
         m.v = Var(NonNegativeIntegers, dense=False)
         m.ref = Reference(m.v, ctype=None)
@@ -1360,8 +1357,8 @@ def test_pprint_nonfinite_sets_ctypeNone(self):
 1 IndexedComponent Declarations
     ref : Size=2, Index=NonNegativeIntegers, ReferenceTo=v
         Key : Object
-          3 : <class 'pyomo.core.base.var._GeneralVarData'>
-          5 : <class 'pyomo.core.base.var._GeneralVarData'>
+          3 : <class 'pyomo.core.base.var.VarData'>
+          5 : <class 'pyomo.core.base.var.VarData'>
 
 2 Declarations: v ref
 """.strip(),
@@ -1380,7 +1377,7 @@ def b(b, i):
         self.assertEqual(
             buf.getvalue().strip(),
             """
-r : Size=4, Index=r_index, ReferenceTo=b[:].x[:]
+r : Size=4, Index=ReferenceSet(b[:].x[:]), ReferenceTo=b[:].x[:]
     Key    : Lower : Value : Upper : Fixed : Stale : Domain
     (1, 3) :     1 :  None :  None : False :  True :  Reals
     (1, 4) :     1 :  None :  None : False :  True :  Reals
diff --git a/pyomo/core/tests/unit/test_relational_expr.py b/pyomo/core/tests/unit/test_relational_expr.py
index f55bfff108c..d361bfcc83c 100644
--- a/pyomo/core/tests/unit/test_relational_expr.py
+++ b/pyomo/core/tests/unit/test_relational_expr.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_set.py b/pyomo/core/tests/unit/test_set.py
index 72231bb08d7..2b0da8b861d 100644
--- a/pyomo/core/tests/unit/test_set.py
+++ b/pyomo/core/tests/unit/test_set.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -60,8 +60,8 @@
     FiniteSetOf,
     InfiniteSetOf,
     RangeSet,
-    _FiniteRangeSetData,
-    _InfiniteRangeSetData,
+    FiniteRangeSetData,
+    InfiniteRangeSetData,
     FiniteScalarRangeSet,
     InfiniteScalarRangeSet,
     AbstractFiniteScalarRangeSet,
@@ -81,10 +81,10 @@
     SetProduct_InfiniteSet,
     SetProduct_FiniteSet,
     SetProduct_OrderedSet,
-    _SetData,
-    _FiniteSetData,
-    _InsertionOrderSetData,
-    _SortedSetData,
+    SetData,
+    FiniteSetData,
+    InsertionOrderSetData,
+    SortedSetData,
     _FiniteSetMixin,
     _OrderedSetMixin,
     SetInitializer,
@@ -112,17 +112,19 @@
 
 class Test_SetInitializer(unittest.TestCase):
     def test_single_set(self):
+        tmp = Set()  # a placeholder to accumulate _anonymous_sets references
+
         a = SetInitializer(None)
         self.assertIs(type(a), SetInitializer)
         self.assertIsNone(a._set)
-        self.assertIs(a(None, None), Any)
+        self.assertIs(a(None, None, tmp), Any)
         self.assertTrue(a.constant())
         self.assertFalse(a.verified)
 
         a = SetInitializer(Reals)
         self.assertIs(type(a), SetInitializer)
         self.assertIs(type(a._set), ConstantInitializer)
-        self.assertIs(a(None, None), Reals)
+        self.assertIs(a(None, None, tmp), Reals)
         self.assertIs(a._set.val, Reals)
         self.assertTrue(a.constant())
         self.assertFalse(a.verified)
@@ -130,18 +132,20 @@ def test_single_set(self):
         a = SetInitializer({1: Reals})
         self.assertIs(type(a), SetInitializer)
         self.assertIs(type(a._set), ItemInitializer)
-        self.assertIs(a(None, 1), Reals)
+        self.assertIs(a(None, 1, tmp), Reals)
         self.assertFalse(a.constant())
         self.assertFalse(a.verified)
 
     def test_intersect(self):
+        tmp = Set()  # a placeholder to accumulate _anonymous_sets references
+
         a = SetInitializer(None)
         a.intersect(SetInitializer(None))
         self.assertIs(type(a), SetInitializer)
         self.assertIsNone(a._set)
         self.assertTrue(a.constant())
         self.assertFalse(a.verified)
-        self.assertIs(a(None, None), Any)
+        self.assertIs(a(None, None, tmp), Any)
 
         a = SetInitializer(None)
         a.intersect(SetInitializer(Reals))
@@ -150,7 +154,7 @@ def test_intersect(self):
         self.assertIs(a._set.val, Reals)
         self.assertTrue(a.constant())
         self.assertFalse(a.verified)
-        self.assertIs(a(None, None), Reals)
+        self.assertIs(a(None, None, tmp), Reals)
 
         a = SetInitializer(None)
         a.intersect(BoundsInitializer(5, default_step=1))
@@ -158,7 +162,7 @@ def test_intersect(self):
         self.assertIs(type(a._set), BoundsInitializer)
         self.assertTrue(a.constant())
         self.assertFalse(a.verified)
-        self.assertEqual(a(None, None), RangeSet(5))
+        self.assertEqual(a(None, None, tmp), RangeSet(5))
 
         a = SetInitializer(Reals)
         a.intersect(SetInitializer(None))
@@ -167,7 +171,7 @@ def test_intersect(self):
         self.assertIs(a._set.val, Reals)
         self.assertTrue(a.constant())
         self.assertFalse(a.verified)
-        self.assertIs(a(None, None), Reals)
+        self.assertIs(a(None, None, tmp), Reals)
 
         a = SetInitializer(Reals)
         a.intersect(SetInitializer(Integers))
@@ -179,7 +183,7 @@ def test_intersect(self):
         self.assertIs(a._set._B.val, Integers)
         self.assertTrue(a.constant())
         self.assertFalse(a.verified)
-        s = a(None, None)
+        s = a(None, None, tmp)
         self.assertIs(type(s), SetIntersection_InfiniteSet)
         self.assertIs(s._sets[0], Reals)
         self.assertIs(s._sets[1], Integers)
@@ -195,7 +199,7 @@ def test_intersect(self):
         self.assertIs(a._set._A._B.val, Integers)
         self.assertTrue(a.constant())
         self.assertFalse(a.verified)
-        s = a(None, None)
+        s = a(None, None, tmp)
         self.assertIs(type(s), SetIntersection_OrderedSet)
         self.assertIs(type(s._sets[0]), SetIntersection_InfiniteSet)
         self.assertIsInstance(s._sets[1], RangeSet)
@@ -212,7 +216,7 @@ def test_intersect(self):
         self.assertIs(a._set._A._B.val, Integers)
         self.assertTrue(a.constant())
         self.assertFalse(a.verified)
-        s = a(None, None)
+        s = a(None, None, tmp)
         self.assertIs(type(s), SetIntersection_InfiniteSet)
         p.construct()
         s.construct()
@@ -236,8 +240,8 @@ def test_intersect(self):
         self.assertFalse(a.constant())
         self.assertFalse(a.verified)
         with self.assertRaises(KeyError):
-            a(None, None)
-        s = a(None, 1)
+            a(None, None, tmp)
+        s = a(None, 1, tmp)
         self.assertIs(type(s), SetIntersection_InfiniteSet)
         p.construct()
         s.construct()
@@ -304,15 +308,17 @@ def test_boundsinit(self):
         self.assertEqual(s, RangeSet(0, 5))
 
     def test_setdefault(self):
+        tmp = Set()  # a placeholder to accumulate _anonymous_sets references
+
         a = SetInitializer(None)
-        self.assertIs(a(None, None), Any)
+        self.assertIs(a(None, None, tmp), Any)
         a.setdefault(Reals)
-        self.assertIs(a(None, None), Reals)
+        self.assertIs(a(None, None, tmp), Reals)
 
         a = SetInitializer(Integers)
-        self.assertIs(a(None, None), Integers)
+        self.assertIs(a(None, None, tmp), Integers)
         a.setdefault(Reals)
-        self.assertIs(a(None, None), Integers)
+        self.assertIs(a(None, None, tmp), Integers)
 
         a = BoundsInitializer(5, default_step=1)
         self.assertEqual(a(None, None), RangeSet(5))
@@ -321,9 +327,9 @@ def test_setdefault(self):
 
         a = SetInitializer(Reals)
         a.intersect(SetInitializer(Integers))
-        self.assertIs(type(a(None, None)), SetIntersection_InfiniteSet)
+        self.assertIs(type(a(None, None, tmp)), SetIntersection_InfiniteSet)
         a.setdefault(RangeSet(5))
-        self.assertIs(type(a(None, None)), SetIntersection_InfiniteSet)
+        self.assertIs(type(a(None, None, tmp)), SetIntersection_InfiniteSet)
 
     def test_indices(self):
         a = SetInitializer(None)
@@ -993,9 +999,7 @@ def __ge__(self, other):
         output = StringIO()
         with LoggingIntercept(output, 'pyomo.core', logging.DEBUG):
             i = SetOf([1, 2, 3])
-            self.assertEqual(output.getvalue(), "")
-            i.construct()
-            ref = 'Constructing SetOf, name=OrderedSetOf, from data=None\n'
+            ref = 'Constructing SetOf, name=[1, 2, 3], from data=None\n'
             self.assertEqual(output.getvalue(), ref)
             # Calling construct() twice bypasses construction the second
             # time around
@@ -1281,19 +1285,19 @@ def test_is_functions(self):
         self.assertTrue(i.isdiscrete())
         self.assertTrue(i.isfinite())
         self.assertTrue(i.isordered())
-        self.assertIsInstance(i, _FiniteRangeSetData)
+        self.assertIsInstance(i, FiniteRangeSetData)
 
         i = RangeSet(1, 3)
         self.assertTrue(i.isdiscrete())
         self.assertTrue(i.isfinite())
         self.assertTrue(i.isordered())
-        self.assertIsInstance(i, _FiniteRangeSetData)
+        self.assertIsInstance(i, FiniteRangeSetData)
 
         i = RangeSet(1, 3, 0)
         self.assertFalse(i.isdiscrete())
         self.assertFalse(i.isfinite())
         self.assertFalse(i.isordered())
-        self.assertIsInstance(i, _InfiniteRangeSetData)
+        self.assertIsInstance(i, InfiniteRangeSetData)
 
     def test_pprint(self):
         m = ConcreteModel()
@@ -1815,7 +1819,7 @@ def test_check_values(self):
 class Test_SetOperator(unittest.TestCase):
     def test_construct(self):
         p = Param(initialize=3)
-        a = RangeSet(p)
+        a = RangeSet(p, name='a')
         output = StringIO()
         with LoggingIntercept(output, 'pyomo.core', logging.DEBUG):
             i = a * a
@@ -1824,12 +1828,8 @@ def test_construct(self):
         with LoggingIntercept(output, 'pyomo.core', logging.DEBUG):
             i.construct()
             ref = (
-                'Constructing SetOperator, name=SetProduct_OrderedSet, '
-                'from data=None\n'
-                'Constructing RangeSet, name=FiniteScalarRangeSet, '
-                'from data=None\n'
-                'Constructing Set, name=SetProduct_OrderedSet, '
-                'from data=None\n'
+                'Constructing SetOperator, name=a*a, from data=None\n'
+                'Constructing RangeSet, name=a, from data=None\n'
             )
             self.assertEqual(output.getvalue(), ref)
             # Calling construct() twice bypasses construction the second
@@ -1941,8 +1941,8 @@ def test_domain_and_pprint(self):
         m.A.pprint(ostream=output)
         ref = """
 A : Size=1, Index=None, Ordered=True
-    Key  : Dimen : Domain        : Size : Members
-    None :     1 : I | A_index_0 :    4 : {1, 2, 3, 4}
+    Key  : Dimen : Domain     : Size : Members
+    None :     1 : I | {3, 4} :    4 : {1, 2, 3, 4}
 """.strip()
         self.assertEqual(output.getvalue().strip(), ref)
 
@@ -2217,8 +2217,8 @@ def test_domain_and_pprint(self):
         m.A.pprint(ostream=output)
         ref = """
 A : Size=1, Index=None, Ordered=True
-    Key  : Dimen : Domain        : Size : Members
-    None :     1 : I & A_index_0 :    0 :      {}
+    Key  : Dimen : Domain     : Size : Members
+    None :     1 : I & {3, 4} :    0 :      {}
 """.strip()
         self.assertEqual(output.getvalue().strip(), ref)
 
@@ -2495,8 +2495,8 @@ def test_domain_and_pprint(self):
         m.A.pprint(ostream=output)
         ref = """
 A : Size=1, Index=None, Ordered=True
-    Key  : Dimen : Domain        : Size : Members
-    None :     1 : I - A_index_0 :    2 : {1, 2}
+    Key  : Dimen : Domain     : Size : Members
+    None :     1 : I - {3, 4} :    2 : {1, 2}
 """.strip()
         self.assertEqual(output.getvalue().strip(), ref)
 
@@ -2724,8 +2724,8 @@ def test_domain_and_pprint(self):
         m.A.pprint(ostream=output)
         ref = """
 A : Size=1, Index=None, Ordered=True
-    Key  : Dimen : Domain        : Size : Members
-    None :     1 : I ^ A_index_0 :    4 : {1, 2, 3, 4}
+    Key  : Dimen : Domain     : Size : Members
+    None :     1 : I ^ {3, 4} :    4 : {1, 2, 3, 4}
 """.strip()
         self.assertEqual(output.getvalue().strip(), ref)
 
@@ -2986,8 +2986,8 @@ def test_domain_and_pprint(self):
         m.A.pprint(ostream=output)
         ref = """
 A : Size=1, Index=None, Ordered=True
-    Key  : Dimen : Domain      : Size : Members
-    None :     2 : I*A_index_0 :    4 : {(1, 3), (1, 4), (2, 3), (2, 4)}
+    Key  : Dimen : Domain   : Size : Members
+    None :     2 : I*{3, 4} :    4 : {(1, 3), (1, 4), (2, 3), (2, 4)}
 """.strip()
         self.assertEqual(output.getvalue().strip(), ref)
 
@@ -3102,7 +3102,7 @@ def test_no_normalize_index(self):
             x = I * J
 
             normalize_index.flatten = False
-            self.assertIs(x.dimen, None)
+            self.assertIs(x.dimen, 2)
             self.assertIn(((1, 2), 3), x)
             self.assertIn((1, (2, 3)), x)
             # if we are not flattening, then lookup must match the
@@ -3277,7 +3277,7 @@ def test_ordered_multidim_setproduct(self):
                 ((3, 4), (7, 8)),
             ]
             self.assertEqual(list(x), ref)
-            self.assertEqual(x.dimen, None)
+            self.assertEqual(x.dimen, 2)
         finally:
             SetModule.FLATTEN_CROSS_PRODUCT = origFlattenCross
 
@@ -3321,7 +3321,7 @@ def test_ordered_nondim_setproduct(self):
                 (1, (2, 3), 5),
             ]
             self.assertEqual(list(x), ref)
-            self.assertEqual(x.dimen, None)
+            self.assertEqual(x.dimen, 3)
         finally:
             SetModule.FLATTEN_CROSS_PRODUCT = origFlattenCross
 
@@ -3373,7 +3373,7 @@ def test_ordered_nondim_setproduct(self):
             self.assertEqual(list(x), ref)
             for i, v in enumerate(ref):
                 self.assertEqual(x[i + 1], v)
-            self.assertEqual(x.dimen, None)
+            self.assertEqual(x.dimen, 4)
         finally:
             SetModule.FLATTEN_CROSS_PRODUCT = origFlattenCross
 
@@ -4137,9 +4137,9 @@ def test_indexed_set(self):
         self.assertFalse(m.I[1].isordered())
         self.assertFalse(m.I[2].isordered())
         self.assertFalse(m.I[3].isordered())
-        self.assertIs(type(m.I[1]), _FiniteSetData)
-        self.assertIs(type(m.I[2]), _FiniteSetData)
-        self.assertIs(type(m.I[3]), _FiniteSetData)
+        self.assertIs(type(m.I[1]), FiniteSetData)
+        self.assertIs(type(m.I[2]), FiniteSetData)
+        self.assertIs(type(m.I[3]), FiniteSetData)
         self.assertEqual(m.I.data(), {1: (1,), 2: (2,), 3: (4,)})
 
         # Explicit (constant) construction
@@ -4155,9 +4155,9 @@ def test_indexed_set(self):
         self.assertTrue(m.I[1].isordered())
         self.assertTrue(m.I[2].isordered())
         self.assertTrue(m.I[3].isordered())
-        self.assertIs(type(m.I[1]), _InsertionOrderSetData)
-        self.assertIs(type(m.I[2]), _InsertionOrderSetData)
-        self.assertIs(type(m.I[3]), _InsertionOrderSetData)
+        self.assertIs(type(m.I[1]), InsertionOrderSetData)
+        self.assertIs(type(m.I[2]), InsertionOrderSetData)
+        self.assertIs(type(m.I[3]), InsertionOrderSetData)
         self.assertEqual(m.I.data(), {1: (4, 2, 5), 2: (4, 2, 5), 3: (4, 2, 5)})
 
         # Explicit (constant) construction
@@ -4173,9 +4173,9 @@ def test_indexed_set(self):
         self.assertTrue(m.I[1].isordered())
         self.assertTrue(m.I[2].isordered())
         self.assertTrue(m.I[3].isordered())
-        self.assertIs(type(m.I[1]), _SortedSetData)
-        self.assertIs(type(m.I[2]), _SortedSetData)
-        self.assertIs(type(m.I[3]), _SortedSetData)
+        self.assertIs(type(m.I[1]), SortedSetData)
+        self.assertIs(type(m.I[2]), SortedSetData)
+        self.assertIs(type(m.I[3]), SortedSetData)
         self.assertEqual(m.I.data(), {1: (2, 4, 5), 2: (2, 4, 5), 3: (2, 4, 5)})
 
         # Explicit (procedural) construction
@@ -4300,7 +4300,7 @@ def _l_tri(model, i, j):
         # This tests a filter that matches the dimentionality of the
         # component.  construct() needs to recognize that the filter is
         # returning a constant in construct() and re-assign it to be the
-        # _filter for each _SetData
+        # _filter for each SetData
         def _lt_3(model, i):
             self.assertIs(model, m)
             return i < 3
@@ -4410,17 +4410,17 @@ def test_domain(self):
         self.assertEqual(list(m.I), [0, 2.0, 4])
         with self.assertRaisesRegex(
             ValueError,
-            'The value is not in the domain ' r'\(Integers & I_domain_index_0_index_1',
+            r'The value is not in the domain \(Integers & \[0:inf:2\]\) & \[0..9\]',
         ):
             m.I.add(1.5)
         with self.assertRaisesRegex(
             ValueError,
-            'The value is not in the domain ' r'\(Integers & I_domain_index_0_index_1',
+            r'The value is not in the domain \(Integers & \[0:inf:2\]\) & \[0..9\]',
         ):
             m.I.add(1)
         with self.assertRaisesRegex(
             ValueError,
-            'The value is not in the domain ' r'\(Integers & I_domain_index_0_index_1',
+            r'The value is not in the domain \(Integers & \[0:inf:2\]\) & \[0..9\]',
         ):
             m.I.add(10)
 
@@ -4458,8 +4458,8 @@ def myFcn(x):
         Key  : Dimen : Domain : Size : Members
         None :     2 :    Any :    2 : {(3, 4), (1, 2)}
     M : Size=1, Index=None, Ordered=False
-        Key  : Dimen : Domain            : Size : Members
-        None :     1 : Reals - M_index_1 :  Inf : ([-inf..0) | (0..inf])
+        Key  : Dimen : Domain      : Size : Members
+        None :     1 : Reals - [0] :  Inf : ([-inf..0) | (0..inf])
     N : Size=1, Index=None, Ordered=False
         Key  : Dimen : Domain           : Size : Members
         None :     1 : Integers - Reals :  Inf :      []
@@ -4469,12 +4469,7 @@ def myFcn(x):
         Key  : Finite : Members
         None :   True :   [1:3]
 
-1 SetOf Declarations
-    M_index_1 : Dimen=1, Size=1, Bounds=(0, 0)
-        Key  : Ordered : Members
-        None :    True :     [0]
-
-8 Declarations: I_index I J K L M_index_1 M N""".strip(),
+7 Declarations: I_index I J K L M N""".strip(),
         )
 
     def test_pickle(self):
@@ -4548,9 +4543,11 @@ def test_construction(self):
         m.I = Set(initialize=[1, 2, 3])
         m.J = Set(initialize=[4, 5, 6])
         m.K = Set(initialize=[(1, 4), (2, 6), (3, 5)], within=m.I * m.J)
+        m.L = Set(initialize=[1, 3], within=m.I)
         m.II = Set([1, 2, 3], initialize={1: [0], 2: [1, 2], 3: range(3)})
         m.JJ = Set([1, 2, 3], initialize={1: [0], 2: [1, 2], 3: range(3)})
         m.KK = Set([1, 2], initialize=[], dimen=lambda m, i: i)
+        m.LL = Set([2, 3], within=m.II, initialize={2: [1, 2], 3: [1]})
 
         output = StringIO()
         m.I.pprint(ostream=output)
@@ -4560,11 +4557,11 @@ def test_construction(self):
         ref = """
 I : Size=0, Index=None, Ordered=Insertion
     Not constructed
-II : Size=0, Index=II_index, Ordered=Insertion
+II : Size=0, Index={1, 2, 3}, Ordered=Insertion
     Not constructed
 J : Size=0, Index=None, Ordered=Insertion
     Not constructed
-JJ : Size=0, Index=JJ_index, Ordered=Insertion
+JJ : Size=0, Index={1, 2, 3}, Ordered=Insertion
     Not constructed""".strip()
         self.assertEqual(output.getvalue().strip(), ref)
 
@@ -4574,6 +4571,8 @@ def test_construction(self):
                     'I': [-1, 0],
                     'II': {1: [10, 11], 3: [30]},
                     'K': [-1, 4, -1, 6, 0, 5],
+                    'L': [-1],
+                    'LL': {3: [30]},
                 }
             }
         )
@@ -4581,6 +4580,7 @@ def test_construction(self):
         self.assertEqual(list(i.I), [-1, 0])
         self.assertEqual(list(i.J), [4, 5, 6])
         self.assertEqual(list(i.K), [(-1, 4), (-1, 6), (0, 5)])
+        self.assertEqual(list(i.L), [-1])
         self.assertEqual(list(i.II[1]), [10, 11])
         self.assertEqual(list(i.II[3]), [30])
         self.assertEqual(list(i.JJ[1]), [0])
@@ -4588,9 +4588,11 @@ def test_construction(self):
         self.assertEqual(list(i.JJ[3]), [0, 1, 2])
         self.assertEqual(list(i.KK[1]), [])
         self.assertEqual(list(i.KK[2]), [])
+        self.assertEqual(list(i.LL[3]), [30])
 
         # Implicitly-constructed set should fall back on initialize!
         self.assertEqual(list(i.II[2]), [1, 2])
+        self.assertEqual(list(i.LL[2]), [1, 2])
 
         # Additional tests for tuplize:
         i = m.create_instance(data={None: {'K': [(1, 4), (2, 6)], 'KK': [1, 4, 2, 6]}})
@@ -4831,7 +4833,7 @@ def _i_init(m, i):
         output = StringIO()
         m.I.pprint(ostream=output)
         ref = """
-I : Size=2, Index=I_index, Ordered=Insertion
+I : Size=2, Index={1, 2, 3, 4, 5}, Ordered=Insertion
     Key : Dimen : Domain : Size : Members
       2 :     1 :    Any :    2 : {0, 1}
       4 :     1 :    Any :    4 : {0, 1, 2, 3}
@@ -5261,7 +5263,7 @@ def test_no_normalize_index(self):
             m.I = Set()
             self.assertIs(m.I._dimen, UnknownSetDimen)
             self.assertTrue(m.I.add((1, (2, 3))))
-            self.assertIs(m.I._dimen, None)
+            self.assertIs(m.I._dimen, 2)
             self.assertNotIn(((1, 2), 3), m.I)
             self.assertIn((1, (2, 3)), m.I)
             self.assertNotIn((1, 2, 3), m.I)
@@ -5302,15 +5304,15 @@ def test_no_normalize_index(self):
 
 
 class TestAbstractSetAPI(unittest.TestCase):
-    def test_SetData(self):
+    def testSetData(self):
         # This tests an anstract non-finite set API
 
         m = ConcreteModel()
         m.I = Set(initialize=[1])
-        s = _SetData(m.I)
+        s = SetData(m.I)
 
         #
-        # _SetData API
+        # SetData API
         #
 
         with self.assertRaises(DeveloperError):
@@ -5400,7 +5402,7 @@ def test_SetData(self):
 
     def test_FiniteMixin(self):
         # This tests an anstract finite set API
-        class FiniteMixin(_FiniteSetMixin, _SetData):
+        class FiniteMixin(_FiniteSetMixin, SetData):
             pass
 
         m = ConcreteModel()
@@ -5408,7 +5410,7 @@ class FiniteMixin(_FiniteSetMixin, _SetData):
         s = FiniteMixin(m.I)
 
         #
-        # _SetData API
+        # SetData API
         #
 
         with self.assertRaises(DeveloperError):
@@ -5525,7 +5527,7 @@ class FiniteMixin(_FiniteSetMixin, _SetData):
 
     def test_OrderedMixin(self):
         # This tests an anstract ordered set API
-        class OrderedMixin(_OrderedSetMixin, _FiniteSetMixin, _SetData):
+        class OrderedMixin(_OrderedSetMixin, _FiniteSetMixin, SetData):
             pass
 
         m = ConcreteModel()
@@ -5533,7 +5535,7 @@ class OrderedMixin(_OrderedSetMixin, _FiniteSetMixin, _SetData):
         s = OrderedMixin(m.I)
 
         #
-        # _SetData API
+        # SetData API
         #
 
         with self.assertRaises(DeveloperError):
@@ -6272,7 +6274,6 @@ def test_issue_835(self):
 
     @unittest.skipIf(NamedTuple is None, "typing module not available")
     def test_issue_938(self):
-        self.maxDiff = None
         NodeKey = NamedTuple('NodeKey', [('id', int)])
         ArcKey = NamedTuple('ArcKey', [('node_from', NodeKey), ('node_to', NodeKey)])
 
@@ -6305,14 +6306,11 @@ def objective_rule(model_arg):
             output = StringIO()
             m.pprint(ostream=output)
             ref = """
-3 Set Declarations
+2 Set Declarations
     arc_keys : Set of arcs
         Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain          : Size : Members
-        None :     2 : arc_keys_domain :    2 : {(0, 0), (0, 1)}
-    arc_keys_domain : Size=1, Index=None, Ordered=True
         Key  : Dimen : Domain              : Size : Members
-        None :     2 : node_keys*node_keys :    4 : {(0, 0), (0, 1), (1, 0), (1, 1)}
+        None :     2 : node_keys*node_keys :    2 : {(0, 0), (0, 1)}
     node_keys : Set of nodes
         Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
@@ -6329,7 +6327,7 @@ def objective_rule(model_arg):
         Key  : Active : Sense    : Expression
         None :   True : minimize : arc_variables[0,0] + arc_variables[0,1]
 
-5 Declarations: node_keys arc_keys_domain arc_keys arc_variables obj
+4 Declarations: node_keys arc_keys arc_variables obj
 """.strip()
             self.assertEqual(output.getvalue().strip(), ref)
 
@@ -6338,18 +6336,15 @@ def objective_rule(model_arg):
             output = StringIO()
             m.pprint(ostream=output)
             ref = """
-3 Set Declarations
+2 Set Declarations
     arc_keys : Set of arcs
         Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain          : Size : Members
-        None :  None : arc_keys_domain :    2 : {ArcKey(node_from=NodeKey(id=0), node_to=NodeKey(id=0)), ArcKey(node_from=NodeKey(id=0), node_to=NodeKey(id=1))}
-    arc_keys_domain : Size=1, Index=None, Ordered=True
         Key  : Dimen : Domain              : Size : Members
-        None :  None : node_keys*node_keys :    4 : {(NodeKey(id=0), NodeKey(id=0)), (NodeKey(id=0), NodeKey(id=1)), (NodeKey(id=1), NodeKey(id=0)), (NodeKey(id=1), NodeKey(id=1))}
+        None :     2 : node_keys*node_keys :    2 : {ArcKey(node_from=NodeKey(id=0), node_to=NodeKey(id=0)), ArcKey(node_from=NodeKey(id=0), node_to=NodeKey(id=1))}
     node_keys : Set of nodes
         Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
-        None :  None :    Any :    2 : {NodeKey(id=0), NodeKey(id=1)}
+        None :     1 :    Any :    2 : {NodeKey(id=0), NodeKey(id=1)}
 
 1 Var Declarations
     arc_variables : Size=2, Index=arc_keys
@@ -6362,7 +6357,7 @@ def objective_rule(model_arg):
         Key  : Active : Sense    : Expression
         None :   True : minimize : arc_variables[ArcKey(node_from=NodeKey(id=0), node_to=NodeKey(id=0))] + arc_variables[ArcKey(node_from=NodeKey(id=0), node_to=NodeKey(id=1))]
 
-5 Declarations: node_keys arc_keys_domain arc_keys arc_variables obj
+4 Declarations: node_keys arc_keys arc_variables obj
 """.strip()
             self.assertEqual(output.getvalue().strip(), ref)
 
@@ -6400,3 +6395,209 @@ def test_issue_1112(self):
         self.assertEqual(len(vals), 1)
         self.assertIsInstance(vals[0], SetProduct_OrderedSet)
         self.assertIsNot(vals[0], cross)
+
+    def test_issue_3284(self):
+        # test creating (indexed and non-indexed) sets using the within argument
+        # using concrete model and initialization
+        problem = ConcreteModel()
+        # non-indexed sets not using the within argument
+        problem.A = Set(initialize=[1, 2, 3])
+        problem.B = Set(dimen=2, initialize=[(1, 2), (3, 4), (5, 6)])
+        # non-indexed sets using within argument
+        problem.subset_A = Set(within=problem.A, initialize=[2, 3])
+        problem.subset_B = Set(within=problem.B, dimen=2, initialize=[(1, 2), (5, 6)])
+        # indexed sets not using the within argument
+        problem.C = Set(problem.A, initialize={1: [-1, 3], 2: [4, 7], 3: [3, 8]})
+        problem.D = Set(
+            problem.B, initialize={(1, 2): [1, 5], (3, 4): [3], (5, 6): [6, 8, 9]}
+        )
+        # indexed sets using an indexed set for the within argument
+        problem.subset_C = Set(
+            problem.A, within=problem.C, initialize={1: [-1], 2: [4], 3: [3, 8]}
+        )
+        problem.subset_D = Set(
+            problem.B,
+            within=problem.D,
+            initialize={(1, 2): [1, 5], (3, 4): [], (5, 6): [6]},
+        )
+        # indexed sets using a non-indexed set for the within argument
+        problem.E = Set([0, 1], within=problem.A, initialize={0: [1, 2], 1: [3]})
+        problem.F = Set(
+            [(1, 2, 3), (4, 5, 6)],
+            within=problem.B,
+            initialize={(1, 2, 3): [(1, 2)], (4, 5, 6): [(3, 4)]},
+        )
+        # check them
+        self.assertEqual(list(problem.A), [1, 2, 3])
+        self.assertEqual(list(problem.B), [(1, 2), (3, 4), (5, 6)])
+        self.assertEqual(list(problem.subset_A), [2, 3])
+        self.assertEqual(list(problem.subset_B), [(1, 2), (5, 6)])
+        self.assertEqual(list(problem.C[1]), [-1, 3])
+        self.assertEqual(list(problem.C[2]), [4, 7])
+        self.assertEqual(list(problem.C[3]), [3, 8])
+        self.assertEqual(list(problem.D[(1, 2)]), [1, 5])
+        self.assertEqual(list(problem.D[(3, 4)]), [3])
+        self.assertEqual(list(problem.D[(5, 6)]), [6, 8, 9])
+        self.assertEqual(list(problem.subset_C[1]), [-1])
+        self.assertEqual(list(problem.subset_C[2]), [4])
+        self.assertEqual(list(problem.subset_C[3]), [3, 8])
+        self.assertEqual(list(problem.subset_D[(1, 2)]), [1, 5])
+        self.assertEqual(list(problem.subset_D[(3, 4)]), [])
+        self.assertEqual(list(problem.subset_D[(5, 6)]), [6])
+        self.assertEqual(list(problem.E[0]), [1, 2])
+        self.assertEqual(list(problem.E[1]), [3])
+        self.assertEqual(list(problem.F[(1, 2, 3)]), [(1, 2)])
+        self.assertEqual(list(problem.F[(4, 5, 6)]), [(3, 4)])
+
+        # try adding elements to test the domains (1 compatible, 1 incompatible)
+        # set subset_A
+        problem.subset_A.add(1)
+        error_message = (
+            "Cannot add value 4 to Set subset_A.\n\tThe value is not in the domain A"
+        )
+        with self.assertRaisesRegex(ValueError, error_message):
+            problem.subset_A.add(4)
+        # set subset_B
+        problem.subset_B.add((3, 4))
+        with self.assertRaisesRegex(ValueError, r".*Cannot add value \(7, 8\)"):
+            problem.subset_B.add((7, 8))
+        # set subset_C
+        problem.subset_C[2].add(7)
+        with self.assertRaisesRegex(ValueError, ".*Cannot add value 8 to Set"):
+            problem.subset_C[2].add(8)
+        # set subset_D
+        problem.subset_D[(5, 6)].add(9)
+        with self.assertRaisesRegex(ValueError, ".*Cannot add value 2 to Set"):
+            problem.subset_D[(3, 4)].add(2)
+        # set E
+        problem.E[1].add(2)
+        with self.assertRaisesRegex(ValueError, ".*Cannot add value 4 to Set"):
+            problem.E[1].add(4)
+        # set F
+        problem.F[(1, 2, 3)].add((3, 4))
+        with self.assertRaisesRegex(ValueError, r".*Cannot add value \(4, 3\)"):
+            problem.F[(4, 5, 6)].add((4, 3))
+        # check them
+        self.assertEqual(list(problem.A), [1, 2, 3])
+        self.assertEqual(list(problem.B), [(1, 2), (3, 4), (5, 6)])
+        self.assertEqual(list(problem.subset_A), [2, 3, 1])
+        self.assertEqual(list(problem.subset_B), [(1, 2), (5, 6), (3, 4)])
+        self.assertEqual(list(problem.C[1]), [-1, 3])
+        self.assertEqual(list(problem.C[2]), [4, 7])
+        self.assertEqual(list(problem.C[3]), [3, 8])
+        self.assertEqual(list(problem.D[(1, 2)]), [1, 5])
+        self.assertEqual(list(problem.D[(3, 4)]), [3])
+        self.assertEqual(list(problem.D[(5, 6)]), [6, 8, 9])
+        self.assertEqual(list(problem.subset_C[1]), [-1])
+        self.assertEqual(list(problem.subset_C[2]), [4, 7])
+        self.assertEqual(list(problem.subset_C[3]), [3, 8])
+        self.assertEqual(list(problem.subset_D[(1, 2)]), [1, 5])
+        self.assertEqual(list(problem.subset_D[(3, 4)]), [])
+        self.assertEqual(list(problem.subset_D[(5, 6)]), [6, 9])
+        self.assertEqual(list(problem.E[0]), [1, 2])
+        self.assertEqual(list(problem.E[1]), [3, 2])
+        self.assertEqual(list(problem.F[(1, 2, 3)]), [(1, 2), (3, 4)])
+        self.assertEqual(list(problem.F[(4, 5, 6)]), [(3, 4)])
+
+        # using abstract model and no initialization
+        model = AbstractModel()
+        # non-indexed sets not using the within argument
+        model.A = Set()
+        model.B = Set(dimen=2)
+        # non-indexed sets using within argument
+        model.subset_A = Set(within=model.A)
+        model.subset_B = Set(within=model.B, dimen=2)
+        # indexed sets not using the within argument
+        model.C = Set(model.A)
+        model.D = Set(model.B)
+        # indexed sets using an indexed set for the within argument
+        model.subset_C = Set(model.A, within=model.C)
+        model.subset_D = Set(model.B, within=model.D)
+        # indexed sets using a non-indexed set for the within argument
+        model.E_index = Set()
+        model.F_index = Set()
+        model.E = Set(model.E_index, within=model.A)
+        model.F = Set(model.F_index, within=model.B)
+        problem = model.create_instance(
+            data={
+                None: {
+                    'A': [3, 4, 5],
+                    'B': [(1, 2), (7, 8)],
+                    'subset_A': [3, 4],
+                    'subset_B': [(1, 2)],
+                    'C': {3: [3], 4: [4, 8], 5: [5, 6]},
+                    'D': {(1, 2): [2], (7, 8): [0, 1]},
+                    'subset_C': {3: [3], 4: [8], 5: []},
+                    'subset_D': {(1, 2): [], (7, 8): [0, 1]},
+                    'E_index': [0, 1],
+                    'F_index': [(1, 2, 3), (4, 5, 6)],
+                    'E': {0: [3, 4], 1: [5]},
+                    'F': {(1, 2, 3): [(1, 2)], (4, 5, 6): [(7, 8)]},
+                }
+            }
+        )
+
+        # check them
+        self.assertEqual(list(problem.A), [3, 4, 5])
+        self.assertEqual(list(problem.B), [(1, 2), (7, 8)])
+        self.assertEqual(list(problem.subset_A), [3, 4])
+        self.assertEqual(list(problem.subset_B), [(1, 2)])
+        self.assertEqual(list(problem.C[3]), [3])
+        self.assertEqual(list(problem.C[4]), [4, 8])
+        self.assertEqual(list(problem.C[5]), [5, 6])
+        self.assertEqual(list(problem.D[(1, 2)]), [2])
+        self.assertEqual(list(problem.D[(7, 8)]), [0, 1])
+        self.assertEqual(list(problem.subset_C[3]), [3])
+        self.assertEqual(list(problem.subset_C[4]), [8])
+        self.assertEqual(list(problem.subset_C[5]), [])
+        self.assertEqual(list(problem.subset_D[(1, 2)]), [])
+        self.assertEqual(list(problem.subset_D[(7, 8)]), [0, 1])
+        self.assertEqual(list(problem.E[0]), [3, 4])
+        self.assertEqual(list(problem.E[1]), [5])
+        self.assertEqual(list(problem.F[(1, 2, 3)]), [(1, 2)])
+        self.assertEqual(list(problem.F[(4, 5, 6)]), [(7, 8)])
+
+        # try adding elements to test the domains (1 compatible, 1 incompatible)
+        # set subset_A
+        problem.subset_A.add(5)
+        with self.assertRaisesRegex(ValueError, ".*Cannot add value "):
+            problem.subset_A.add(6)
+        # set subset_B
+        problem.subset_B.add((7, 8))
+        with self.assertRaisesRegex(ValueError, ".*Cannot add value "):
+            problem.subset_B.add((3, 4))
+        # set subset_C
+        problem.subset_C[4].add(4)
+        with self.assertRaisesRegex(ValueError, ".*Cannot add value "):
+            problem.subset_C[4].add(9)
+        # set subset_D
+        problem.subset_D[(1, 2)].add(2)
+        with self.assertRaisesRegex(ValueError, ".*Cannot add value "):
+            problem.subset_D[(1, 2)].add(3)
+        # set E
+        problem.E[1].add(4)
+        with self.assertRaisesRegex(ValueError, ".*Cannot add value "):
+            problem.E[1].add(1)
+        # set F
+        problem.F[(1, 2, 3)].add((7, 8))
+        with self.assertRaisesRegex(ValueError, ".*Cannot add value "):
+            problem.F[(4, 5, 6)].add((4, 3))
+        # check them
+        self.assertEqual(list(problem.A), [3, 4, 5])
+        self.assertEqual(list(problem.B), [(1, 2), (7, 8)])
+        self.assertEqual(list(problem.subset_A), [3, 4, 5])
+        self.assertEqual(list(problem.subset_B), [(1, 2), (7, 8)])
+        self.assertEqual(list(problem.C[3]), [3])
+        self.assertEqual(list(problem.C[4]), [4, 8])
+        self.assertEqual(list(problem.C[5]), [5, 6])
+        self.assertEqual(list(problem.D[(1, 2)]), [2])
+        self.assertEqual(list(problem.D[(7, 8)]), [0, 1])
+        self.assertEqual(list(problem.subset_C[3]), [3])
+        self.assertEqual(list(problem.subset_C[4]), [8, 4])
+        self.assertEqual(list(problem.subset_C[5]), [])
+        self.assertEqual(list(problem.subset_D[(1, 2)]), [2])
+        self.assertEqual(list(problem.subset_D[(7, 8)]), [0, 1])
+        self.assertEqual(list(problem.E[0]), [3, 4])
+        self.assertEqual(list(problem.E[1]), [5, 4])
+        self.assertEqual(list(problem.F[(1, 2, 3)]), [(1, 2), (7, 8)])
+        self.assertEqual(list(problem.F[(4, 5, 6)]), [(7, 8)])
diff --git a/pyomo/core/tests/unit/test_sets.py b/pyomo/core/tests/unit/test_sets.py
index 90668a28e72..4d305ebab86 100644
--- a/pyomo/core/tests/unit/test_sets.py
+++ b/pyomo/core/tests/unit/test_sets.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -1051,7 +1051,7 @@ def setUp(self):
         self.instance = self.model.create_instance(currdir + "setA.dat")
         self.e1 = numpy.bool_(1)
         self.e2 = numpy.int_(2)
-        self.e3 = numpy.float_(3.0)
+        self.e3 = numpy.float64(3.0)
         self.e4 = numpy.int_(4)
         self.e5 = numpy.int_(5)
         self.e6 = numpy.int_(6)
@@ -1068,7 +1068,7 @@ def test_numpy_int(self):
 
     def test_numpy_float(self):
         model = ConcreteModel()
-        model.A = Set(initialize=[numpy.float_(1.0), numpy.float_(0.0)])
+        model.A = Set(initialize=[numpy.float64(1.0), numpy.float64(0.0)])
         self.assertEqual(model.A.bounds(), (0, 1))
 
 
@@ -3213,7 +3213,7 @@ def test_numpy_membership(self):
         self.assertEqual(numpy.int_(1) in Boolean, True)
         self.assertEqual(numpy.bool_(True) in Boolean, True)
         self.assertEqual(numpy.bool_(False) in Boolean, True)
-        self.assertEqual(numpy.float_(1.1) in Boolean, False)
+        self.assertEqual(numpy.float64(1.1) in Boolean, False)
         self.assertEqual(numpy.int_(2) in Boolean, False)
 
         self.assertEqual(numpy.int_(0) in Integers, True)
@@ -3222,7 +3222,7 @@ def test_numpy_membership(self):
         # identically to 1
         self.assertEqual(numpy.bool_(True) in Integers, True)
         self.assertEqual(numpy.bool_(False) in Integers, True)
-        self.assertEqual(numpy.float_(1.1) in Integers, False)
+        self.assertEqual(numpy.float64(1.1) in Integers, False)
         self.assertEqual(numpy.int_(2) in Integers, True)
 
         self.assertEqual(numpy.int_(0) in Reals, True)
@@ -3231,14 +3231,14 @@ def test_numpy_membership(self):
         # identically to 1
         self.assertEqual(numpy.bool_(True) in Reals, True)
         self.assertEqual(numpy.bool_(False) in Reals, True)
-        self.assertEqual(numpy.float_(1.1) in Reals, True)
+        self.assertEqual(numpy.float64(1.1) in Reals, True)
         self.assertEqual(numpy.int_(2) in Reals, True)
 
         self.assertEqual(numpy.int_(0) in Any, True)
         self.assertEqual(numpy.int_(1) in Any, True)
         self.assertEqual(numpy.bool_(True) in Any, True)
         self.assertEqual(numpy.bool_(False) in Any, True)
-        self.assertEqual(numpy.float_(1.1) in Any, True)
+        self.assertEqual(numpy.float64(1.1) in Any, True)
         self.assertEqual(numpy.int_(2) in Any, True)
 
     def test_setargs1(self):
diff --git a/pyomo/core/tests/unit/test_smap.py b/pyomo/core/tests/unit/test_smap.py
index 2b9d2f192c0..69448916a04 100644
--- a/pyomo/core/tests/unit/test_smap.py
+++ b/pyomo/core/tests/unit/test_smap.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_sos.py b/pyomo/core/tests/unit/test_sos.py
index 92a8a5eabaa..cacfcdf5d42 100644
--- a/pyomo/core/tests/unit/test_sos.py
+++ b/pyomo/core/tests/unit/test_sos.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_sos_v2.py b/pyomo/core/tests/unit/test_sos_v2.py
index 8b6fab549a2..996dd10829d 100644
--- a/pyomo/core/tests/unit/test_sos_v2.py
+++ b/pyomo/core/tests/unit/test_sos_v2.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # *****************************************************************************
 # *****************************************************************************
 
diff --git a/pyomo/core/tests/unit/test_suffix.py b/pyomo/core/tests/unit/test_suffix.py
index 1ec1af9d919..d2e861cceb5 100644
--- a/pyomo/core/tests/unit/test_suffix.py
+++ b/pyomo/core/tests/unit/test_suffix.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_symbol_map.py b/pyomo/core/tests/unit/test_symbol_map.py
index 5f6416e2c8d..773e6d335f1 100644
--- a/pyomo/core/tests/unit/test_symbol_map.py
+++ b/pyomo/core/tests/unit/test_symbol_map.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_symbolic.py b/pyomo/core/tests/unit/test_symbolic.py
index bbac4599363..91887f27bb7 100644
--- a/pyomo/core/tests/unit/test_symbolic.py
+++ b/pyomo/core/tests/unit/test_symbolic.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_taylor_series.py b/pyomo/core/tests/unit/test_taylor_series.py
index d4fe5291b2d..4b36451d222 100644
--- a/pyomo/core/tests/unit/test_taylor_series.py
+++ b/pyomo/core/tests/unit/test_taylor_series.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_template_expr.py b/pyomo/core/tests/unit/test_template_expr.py
index 4b4ea494b0e..80f5d90b60e 100644
--- a/pyomo/core/tests/unit/test_template_expr.py
+++ b/pyomo/core/tests/unit/test_template_expr.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -127,7 +127,7 @@ def test_template_scalar_with_set(self):
         # Note that structural expressions do not implement polynomial_degree
         with self.assertRaisesRegex(
             AttributeError,
-            "'_InsertionOrderSetData' object has " "no attribute 'polynomial_degree'",
+            "'InsertionOrderSetData' object has " "no attribute 'polynomial_degree'",
         ):
             e.polynomial_degree()
         self.assertEqual(str(e), "s[{I}]")
@@ -490,14 +490,14 @@ def c(m):
         self.assertEqual(
             str(resolve_template(template)),
             'x[1,1,10] + '
-            '(x[2,1,10] + x[2,1,20]) + '
-            '(x[3,1,10] + x[3,1,20] + x[3,1,30]) + '
-            '(x[1,2,10]) + '
-            '(x[2,2,10] + x[2,2,20]) + '
-            '(x[3,2,10] + x[3,2,20] + x[3,2,30]) + '
-            '(x[1,3,10]) + '
-            '(x[2,3,10] + x[2,3,20]) + '
-            '(x[3,3,10] + x[3,3,20] + x[3,3,30])  <=  0',
+            'x[2,1,10] + x[2,1,20] + '
+            'x[3,1,10] + x[3,1,20] + x[3,1,30] + '
+            'x[1,2,10] + '
+            'x[2,2,10] + x[2,2,20] + '
+            'x[3,2,10] + x[3,2,20] + x[3,2,30] + '
+            'x[1,3,10] + '
+            'x[2,3,10] + x[2,3,20] + '
+            'x[3,3,10] + x[3,3,20] + x[3,3,30]  <=  0',
         )
 
     def test_multidim_nested_sum_rule(self):
@@ -566,14 +566,14 @@ def c(m):
         self.assertEqual(
             str(resolve_template(template)),
             'x[1,1,10] + '
-            '(x[2,1,10] + x[2,1,20]) + '
-            '(x[3,1,10] + x[3,1,20] + x[3,1,30]) + '
-            '(x[1,2,10]) + '
-            '(x[2,2,10] + x[2,2,20]) + '
-            '(x[3,2,10] + x[3,2,20] + x[3,2,30]) + '
-            '(x[1,3,10]) + '
-            '(x[2,3,10] + x[2,3,20]) + '
-            '(x[3,3,10] + x[3,3,20] + x[3,3,30])  <=  0',
+            'x[2,1,10] + x[2,1,20] + '
+            'x[3,1,10] + x[3,1,20] + x[3,1,30] + '
+            'x[1,2,10] + '
+            'x[2,2,10] + x[2,2,20] + '
+            'x[3,2,10] + x[3,2,20] + x[3,2,30] + '
+            'x[1,3,10] + '
+            'x[2,3,10] + x[2,3,20] + '
+            'x[3,3,10] + x[3,3,20] + x[3,3,30]  <=  0',
         )
 
     def test_multidim_nested_getattr_sum_rule(self):
@@ -609,14 +609,14 @@ def c(m):
         self.assertEqual(
             str(resolve_template(template)),
             'x[1,1,10] + '
-            '(x[2,1,10] + x[2,1,20]) + '
-            '(x[3,1,10] + x[3,1,20] + x[3,1,30]) + '
-            '(x[1,2,10]) + '
-            '(x[2,2,10] + x[2,2,20]) + '
-            '(x[3,2,10] + x[3,2,20] + x[3,2,30]) + '
-            '(x[1,3,10]) + '
-            '(x[2,3,10] + x[2,3,20]) + '
-            '(x[3,3,10] + x[3,3,20] + x[3,3,30])  <=  0',
+            'x[2,1,10] + x[2,1,20] + '
+            'x[3,1,10] + x[3,1,20] + x[3,1,30] + '
+            'x[1,2,10] + '
+            'x[2,2,10] + x[2,2,20] + '
+            'x[3,2,10] + x[3,2,20] + x[3,2,30] + '
+            'x[1,3,10] + '
+            'x[2,3,10] + x[2,3,20] + '
+            'x[3,3,10] + x[3,3,20] + x[3,3,30]  <=  0',
         )
 
     def test_eval_getattr(self):
diff --git a/pyomo/core/tests/unit/test_units.py b/pyomo/core/tests/unit/test_units.py
index 809db733cde..bda62835711 100644
--- a/pyomo/core/tests/unit/test_units.py
+++ b/pyomo/core/tests/unit/test_units.py
@@ -2,7 +2,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_var.py b/pyomo/core/tests/unit/test_var.py
index 33e46a79e9b..6b2e92be832 100644
--- a/pyomo/core/tests/unit/test_var.py
+++ b/pyomo/core/tests/unit/test_var.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/test_var_set_bounds.py b/pyomo/core/tests/unit/test_var_set_bounds.py
index eb969c2ca73..1686ba4f1c6 100644
--- a/pyomo/core/tests/unit/test_var_set_bounds.py
+++ b/pyomo/core/tests/unit/test_var_set_bounds.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -36,7 +36,7 @@
 # GAH: These tests been temporarily disabled. It is no longer the job of Var
 #      to validate its domain at the time of construction. It only needs to
 #      ensure that whatever object is passed as its domain is suitable for
-#      interacting with the _VarData interface (e.g., has a bounds method)
+#      interacting with the VarData interface (e.g., has a bounds method)
 #      The plan is to start adding functionality to the solver interfaces
 #      that will support custom domains.
 
diff --git a/pyomo/core/tests/unit/test_visitor.py b/pyomo/core/tests/unit/test_visitor.py
index 086c57aa560..5733710ab46 100644
--- a/pyomo/core/tests/unit/test_visitor.py
+++ b/pyomo/core/tests/unit/test_visitor.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -72,7 +72,7 @@
     RECURSION_LIMIT,
     get_stack_depth,
 )
-from pyomo.core.base.param import _ParamData, ScalarParam
+from pyomo.core.base.param import ParamData, ScalarParam
 from pyomo.core.expr.template_expr import IndexTemplate
 from pyomo.common.collections import ComponentSet
 from pyomo.common.errors import TemplateExpressionError
@@ -145,7 +145,8 @@ def test_identify_vars_vars(self):
         self.assertEqual(list(identify_variables(m.a + m.b[1])), [m.a, m.b[1]])
         self.assertEqual(list(identify_variables(m.a ** m.b[1])), [m.a, m.b[1]])
         self.assertEqual(
-            list(identify_variables(m.a ** m.b[1] + m.b[2])), [m.b[2], m.a, m.b[1]]
+            ComponentSet(identify_variables(m.a ** m.b[1] + m.b[2])),
+            ComponentSet([m.b[2], m.a, m.b[1]]),
         )
         self.assertEqual(
             list(identify_variables(m.a ** m.b[1] + m.b[2] * m.b[3] * m.b[2])),
@@ -159,14 +160,20 @@ def test_identify_vars_vars(self):
         # Identify variables in the arguments to functions
         #
         self.assertEqual(
-            list(identify_variables(m.x(m.a, 'string_param', 1, []) * m.b[1])),
-            [m.b[1], m.a],
+            ComponentSet(identify_variables(m.x(m.a, 'string_param', 1, []) * m.b[1])),
+            ComponentSet([m.b[1], m.a]),
         )
         self.assertEqual(
             list(identify_variables(m.x(m.p, 'string_param', 1, []) * m.b[1])), [m.b[1]]
         )
-        self.assertEqual(list(identify_variables(tanh(m.a) * m.b[1])), [m.b[1], m.a])
-        self.assertEqual(list(identify_variables(abs(m.a) * m.b[1])), [m.b[1], m.a])
+        self.assertEqual(
+            ComponentSet(identify_variables(tanh(m.a) * m.b[1])),
+            ComponentSet([m.b[1], m.a]),
+        )
+        self.assertEqual(
+            ComponentSet(identify_variables(abs(m.a) * m.b[1])),
+            ComponentSet([m.b[1], m.a]),
+        )
         #
         # Check logic for allowing duplicates
         #
@@ -405,7 +412,6 @@ def test_replacement_walker0(self):
         )
 
         del M.w
-        del M.w_index
         M.w = VarList()
         e = 2 * sum_product(M.z, M.x)
         walker = ReplacementWalkerTest1(M)
@@ -438,9 +444,7 @@ def test_replacement_linear_expression_with_constant(self):
         sub_map = dict()
         sub_map[id(m.x)] = 5
         e2 = replace_expressions(e, sub_map)
-        assertExpressionsEqual(
-            self, e2, LinearExpression([10, MonomialTermExpression((1, m.y))])
-        )
+        assertExpressionsEqual(self, e2, LinearExpression([10, m.y]))
 
         e = LinearExpression(linear_coefs=[2, 3], linear_vars=[m.x, m.y])
         sub_map = dict()
@@ -688,7 +692,7 @@ def __init__(self, model):
         self.model = model
 
     def visiting_potential_leaf(self, node):
-        if node.__class__ in (_ParamData, ScalarParam):
+        if node.__class__ in (ParamData, ScalarParam):
             if id(node) in self.substitute:
                 return True, self.substitute[id(node)]
             self.substitute[id(node)] = 2 * self.model.w.add()
@@ -887,20 +891,7 @@ def test_replace(self):
         assertExpressionsEqual(
             self,
             SumExpression(
-                [
-                    LinearExpression(
-                        [
-                            MonomialTermExpression((1, m.y[1])),
-                            MonomialTermExpression((1, m.y[2])),
-                        ]
-                    ),
-                    LinearExpression(
-                        [
-                            MonomialTermExpression((1, m.y[2])),
-                            MonomialTermExpression((1, m.y[3])),
-                        ]
-                    ),
-                ]
+                [LinearExpression([m.y[1], m.y[2]]), LinearExpression([m.y[2], m.y[3]])]
             )
             == 0,
             f,
@@ -931,9 +922,7 @@ def test_npv_sum(self):
         e3 = replace_expressions(e1, {id(m.p1): m.x})
 
         assertExpressionsEqual(self, e2, m.p2 + 2)
-        assertExpressionsEqual(
-            self, e3, LinearExpression([MonomialTermExpression((1, m.x)), 2])
-        )
+        assertExpressionsEqual(self, e3, LinearExpression([m.x, 2]))
 
     def test_npv_negation(self):
         m = ConcreteModel()
diff --git a/pyomo/core/tests/unit/test_xfrm_discrete_vars.py b/pyomo/core/tests/unit/test_xfrm_discrete_vars.py
index ae630586480..d0e74c8cae3 100644
--- a/pyomo/core/tests/unit/test_xfrm_discrete_vars.py
+++ b/pyomo/core/tests/unit/test_xfrm_discrete_vars.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/uninstantiated_model_linear.py b/pyomo/core/tests/unit/uninstantiated_model_linear.py
index 387444b7bc5..417f7763d87 100644
--- a/pyomo/core/tests/unit/uninstantiated_model_linear.py
+++ b/pyomo/core/tests/unit/uninstantiated_model_linear.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/uninstantiated_model_quadratic.py b/pyomo/core/tests/unit/uninstantiated_model_quadratic.py
index 572c6a43a14..350d96a85bb 100644
--- a/pyomo/core/tests/unit/uninstantiated_model_quadratic.py
+++ b/pyomo/core/tests/unit/uninstantiated_model_quadratic.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/core/tests/unit/varpprint.txt b/pyomo/core/tests/unit/varpprint.txt
index bd49b881417..a8c33c6b007 100644
--- a/pyomo/core/tests/unit/varpprint.txt
+++ b/pyomo/core/tests/unit/varpprint.txt
@@ -1,13 +1,7 @@
-3 Set Declarations
+1 Set Declarations
     a : Size=1, Index=None, Ordered=Insertion
         Key  : Dimen : Domain : Size : Members
         None :     1 :    Any :    3 : {1, 2, 3}
-    cl_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :   10 : {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
-    o3_index : Size=1, Index=None, Ordered=True
-        Key  : Dimen : Domain : Size : Members
-        None :     2 :    a*a :    9 : {(1, 1), (1, 2), (1, 3), (2, 1), (2, 2), (2, 3), (3, 1), (3, 2), (3, 3)}
 
 2 Param Declarations
     A : Size=1, Index=None, Domain=Any, Default=-1, Mutable=True
@@ -37,7 +31,7 @@
           1 :   True : minimize :       b[1]
           2 :   True : minimize :       b[2]
           3 :   True : minimize :       b[3]
-    o3 : Size=0, Index=o3_index, Active=True
+    o3 : Size=0, Index=a*a, Active=True
         Key : Active : Sense : Expression
 
 19 Constraint Declarations
@@ -97,7 +91,7 @@
     c9b : Size=1, Index=None, Active=True
         Key  : Lower : Body : Upper : Active
         None :  -Inf :    c : A + A :   True
-    cl : Size=10, Index=cl_index, Active=True
+    cl : Size=10, Index={1, 2, 3, 4, 5, 6, 7, 8, 9, 10}, Active=True
         Key : Lower : Body     : Upper : Active
           1 :  -Inf :    d - c :   0.0 :   True
           2 :  -Inf :  d - 2*c :   0.0 :   True
@@ -110,4 +104,4 @@
           9 :  -Inf :  d - 9*c :   0.0 :   True
          10 :  -Inf : d - 10*c :   0.0 :   True
 
-30 Declarations: a b c d e A B o2 o3_index o3 c1 c2 c3 c4 c5 c6a c7a c7b c8 c9a c9b c10a c11 c15a c16a c12 c13a c14a cl_index cl
+28 Declarations: a b c d e A B o2 o3 c1 c2 c3 c4 c5 c6a c7a c7b c8 c9a c9b c10a c11 c15a c16a c12 c13a c14a cl
diff --git a/pyomo/core/util.py b/pyomo/core/util.py
index 3f8a136e07d..4b6cc8f3320 100644
--- a/pyomo/core/util.py
+++ b/pyomo/core/util.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -13,27 +13,12 @@
 # Utility functions
 #
 
-__all__ = [
-    'sum_product',
-    'summation',
-    'dot_product',
-    'sequence',
-    'prod',
-    'quicksum',
-    'target_list',
-]
-
 from pyomo.common.deprecation import deprecation_warning
 from pyomo.core.expr.numvalue import native_numeric_types
-from pyomo.core.expr.numeric_expr import (
-    mutable_expression,
-    nonlinear_expression,
-    NPV_SumExpression,
-)
-import pyomo.core.expr as EXPR
+from pyomo.core.expr.numeric_expr import mutable_expression, NPV_SumExpression
 from pyomo.core.base.var import Var
 from pyomo.core.base.expression import Expression
-from pyomo.core.base.component import _ComponentBase
+from pyomo.core.base.component import ComponentBase
 import logging
 
 logger = logging.getLogger(__name__)
@@ -253,12 +238,12 @@ def sequence(*args):
 
 
 def target_list(x):
-    if isinstance(x, _ComponentBase):
+    if isinstance(x, ComponentBase):
         return [x]
     elif hasattr(x, '__iter__'):
         ans = []
         for i in x:
-            if isinstance(i, _ComponentBase):
+            if isinstance(i, ComponentBase):
                 ans.append(i)
             else:
                 raise ValueError(
diff --git a/pyomo/dae/__init__.py b/pyomo/dae/__init__.py
index 8d07b184336..5860a129aa2 100644
--- a/pyomo/dae/__init__.py
+++ b/pyomo/dae/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/dae/contset.py b/pyomo/dae/contset.py
index ee4c9f79e89..9b4f11714df 100644
--- a/pyomo/dae/contset.py
+++ b/pyomo/dae/contset.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -17,7 +17,6 @@
 from pyomo.core.base.component import ModelComponentFactory
 
 logger = logging.getLogger('pyomo.dae')
-__all__ = ['ContinuousSet']
 
 
 @ModelComponentFactory.register(
diff --git a/pyomo/dae/diffvar.py b/pyomo/dae/diffvar.py
index 8d75b9ae148..b921107957f 100644
--- a/pyomo/dae/diffvar.py
+++ b/pyomo/dae/diffvar.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -16,8 +16,6 @@
 from pyomo.core.base.var import Var
 from pyomo.dae.contset import ContinuousSet
 
-__all__ = ('DerivativeVar', 'DAE_Error')
-
 
 def create_access_function(var):
     """
diff --git a/pyomo/dae/flatten.py b/pyomo/dae/flatten.py
index 595f90b3dc7..3d90cc443c1 100644
--- a/pyomo/dae/flatten.py
+++ b/pyomo/dae/flatten.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -200,8 +200,28 @@ def slice_component_along_sets(component, sets, context_slice=None, normalize=No
                     #
                     # Note that c_slice is not necessarily a slice.
                     # We enter this loop even if no sets need slicing.
-                    temp_slice = c_slice.duplicate()
-                    next(iter(temp_slice))
+                    try:
+                        next(iter(c_slice.duplicate()))
+                    except IndexError:
+                        if normalize_index.flatten:
+                            raise
+                        # There is an edge case where when we are not
+                        # flattening indices the dimensionality of an
+                        # index can change between a SetProduct and the
+                        # member Sets: the member set can have dimen>1
+                        # (or even None!), but the dimen of that portion
+                        # of the SetProduct is always 1.  Since we are
+                        # just checking that the c_slice isn't
+                        # completely empty, we will allow matching with
+                        # an Ellipsis
+                        _empty = True
+                        try:
+                            next(iter(base_component[...]))
+                            _empty = False
+                        except:
+                            pass
+                        if _empty:
+                            raise
                 if (normalize is None and normalize_index.flatten) or normalize:
                     # Most users probably want this index to be normalized,
                     # so they can more conveniently use it as a key in a
@@ -239,7 +259,7 @@ def generate_sliced_components(
     Parameters
     ----------
 
-    b: _BlockData
+    b: BlockData
         Block whose components will be sliced
 
     index_stack: list
@@ -247,7 +267,7 @@ def generate_sliced_components(
         component, that have been sliced. This is necessary to return the
         sets that have been sliced.
 
-    slice_: IndexedComponent_slice or _BlockData
+    slice_: IndexedComponent_slice or BlockData
         Slice generated so far.  This function will yield extensions to
         this slice at the current level of the block hierarchy.
 
@@ -423,7 +443,7 @@ def flatten_components_along_sets(m, sets, ctype, indices=None, active=None):
     Parameters
     ----------
 
-    m: _BlockData
+    m: BlockData
         Block whose components (and their sub-components) will be
         partitioned
 
@@ -526,7 +546,7 @@ def flatten_dae_components(model, time, ctype, indices=None, active=None):
     Parameters
     ----------
 
-    model: _BlockData
+    model: BlockData
         Block whose components are partitioned
 
     time: Set
diff --git a/pyomo/dae/initialization.py b/pyomo/dae/initialization.py
index c10ccb023d1..97928026de2 100644
--- a/pyomo/dae/initialization.py
+++ b/pyomo/dae/initialization.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/dae/integral.py b/pyomo/dae/integral.py
index 302e50a007d..8c9512d98dd 100644
--- a/pyomo/dae/integral.py
+++ b/pyomo/dae/integral.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -14,15 +14,13 @@
 from pyomo.core.base.indexed_component import rule_wrapper
 from pyomo.core.base.expression import (
     Expression,
-    _GeneralExpressionData,
+    ExpressionData,
     ScalarExpression,
     IndexedExpression,
 )
 from pyomo.dae.contset import ContinuousSet
 from pyomo.dae.diffvar import DAE_Error
 
-__all__ = ('Integral',)
-
 
 @ModelComponentFactory.register("Integral Expression in a DAE model.")
 class Integral(Expression):
@@ -153,7 +151,7 @@ class ScalarIntegral(ScalarExpression, Integral):
     """
 
     def __init__(self, *args, **kwds):
-        _GeneralExpressionData.__init__(self, None, component=self)
+        ExpressionData.__init__(self, None, component=self)
         Integral.__init__(self, *args, **kwds)
 
     def clear(self):
diff --git a/pyomo/dae/misc.py b/pyomo/dae/misc.py
index 9b867bcfff4..dcb73f60c9e 100644
--- a/pyomo/dae/misc.py
+++ b/pyomo/dae/misc.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -263,7 +263,7 @@ def _update_var(v):
     # Note: This is not required it is handled by the _default method on
     #       Var (which is now a IndexedComponent). However, it
     #       would be much slower to rely on that method to generate new
-    #       _VarData for a large number of new indices.
+    #       VarData for a large number of new indices.
     new_indices = set(v.index_set()) - set(v._data.keys())
     for index in new_indices:
         v.add(index)
diff --git a/pyomo/dae/plugins/__init__.py b/pyomo/dae/plugins/__init__.py
index 96ab91b0ac0..681112dd970 100644
--- a/pyomo/dae/plugins/__init__.py
+++ b/pyomo/dae/plugins/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/dae/plugins/colloc.py b/pyomo/dae/plugins/colloc.py
index 7f86e8bc2e2..81f1e4dd7ea 100644
--- a/pyomo/dae/plugins/colloc.py
+++ b/pyomo/dae/plugins/colloc.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/dae/plugins/finitedifference.py b/pyomo/dae/plugins/finitedifference.py
index 71bb2ffc9b6..6557a14e562 100644
--- a/pyomo/dae/plugins/finitedifference.py
+++ b/pyomo/dae/plugins/finitedifference.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/dae/set_utils.py b/pyomo/dae/set_utils.py
index 981954189b3..d7a1d9517d9 100644
--- a/pyomo/dae/set_utils.py
+++ b/pyomo/dae/set_utils.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/dae/simulator.py b/pyomo/dae/simulator.py
index b869592553a..72ba0c7331d 100644
--- a/pyomo/dae/simulator.py
+++ b/pyomo/dae/simulator.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 #  _________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
@@ -6,20 +17,14 @@
 #  the U.S. Government retains certain rights in this software.
 #  This software is distributed under the BSD License.
 #  _________________________________________________________________________
-from pyomo.core.base import Constraint, Param, value, Suffix, Block
+import logging
 
+from pyomo.core.base import Constraint, Param, value, Suffix, Block
 from pyomo.dae import ContinuousSet, DerivativeVar
 from pyomo.dae.diffvar import DAE_Error
-
 import pyomo.core.expr as EXPR
 from pyomo.core.expr.numvalue import native_numeric_types
 from pyomo.core.expr.template_expr import IndexTemplate, _GetItemIndexer
-
-import logging
-
-__all__ = ('Simulator',)
-logger = logging.getLogger('pyomo.core')
-
 from pyomo.common.dependencies import (
     numpy as np,
     numpy_available,
@@ -28,6 +33,8 @@
     attempt_import,
 )
 
+logger = logging.getLogger('pyomo.core')
+
 casadi_intrinsic = {}
 
 
diff --git a/pyomo/dae/tests/__init__.py b/pyomo/dae/tests/__init__.py
index 12bdccd0ef4..4638923595a 100644
--- a/pyomo/dae/tests/__init__.py
+++ b/pyomo/dae/tests/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/dae/tests/test_colloc.py b/pyomo/dae/tests/test_colloc.py
index 0786903f12e..e7e6b20d660 100644
--- a/pyomo/dae/tests/test_colloc.py
+++ b/pyomo/dae/tests/test_colloc.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/dae/tests/test_contset.py b/pyomo/dae/tests/test_contset.py
index ce13d53dfd5..e5f11b90e27 100644
--- a/pyomo/dae/tests/test_contset.py
+++ b/pyomo/dae/tests/test_contset.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/dae/tests/test_diffvar.py b/pyomo/dae/tests/test_diffvar.py
index 718781d5916..414e9341e19 100644
--- a/pyomo/dae/tests/test_diffvar.py
+++ b/pyomo/dae/tests/test_diffvar.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -69,7 +69,6 @@ def test_valid(self):
         del m.dv
         del m.dv2
         del m.v
-        del m.v_index
 
         m.v = Var(m.x, m.t)
         m.dv = DerivativeVar(m.v, wrt=m.x)
diff --git a/pyomo/dae/tests/test_finite_diff.py b/pyomo/dae/tests/test_finite_diff.py
index adca8bf6a15..a1b842feccf 100644
--- a/pyomo/dae/tests/test_finite_diff.py
+++ b/pyomo/dae/tests/test_finite_diff.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/dae/tests/test_flatten.py b/pyomo/dae/tests/test_flatten.py
index a6ea824c3ef..1fc28f66bdf 100644
--- a/pyomo/dae/tests/test_flatten.py
+++ b/pyomo/dae/tests/test_flatten.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -49,6 +49,12 @@ class TestAssumedBehavior(unittest.TestCase):
     immediately obvious would be the case.
     """
 
+    def setUp(self):
+        self._orig_flatten = normalize_index.flatten
+
+    def tearDown(self):
+        normalize_index.flatten = self._orig_flatten
+
     def test_cross(self):
         m = ConcreteModel()
         m.s1 = Set(initialize=[1, 2])
@@ -313,6 +319,12 @@ def c_rule(m, t):
 
 
 class TestFlatten(_TestFlattenBase, unittest.TestCase):
+    def setUp(self):
+        self._orig_flatten = normalize_index.flatten
+
+    def tearDown(self):
+        normalize_index.flatten = self._orig_flatten
+
     def _model1_1d_sets(self):
         # One-dimensional sets, no skipping.
         m = ConcreteModel()
diff --git a/pyomo/dae/tests/test_initialization.py b/pyomo/dae/tests/test_initialization.py
index 390b6ecc59e..8407ad2b2a4 100644
--- a/pyomo/dae/tests/test_initialization.py
+++ b/pyomo/dae/tests/test_initialization.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/dae/tests/test_integral.py b/pyomo/dae/tests/test_integral.py
index 77d6d4dd8a9..933bd97d7b4 100644
--- a/pyomo/dae/tests/test_integral.py
+++ b/pyomo/dae/tests/test_integral.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/dae/tests/test_misc.py b/pyomo/dae/tests/test_misc.py
index 11c4e44b7b0..48c1e48418d 100644
--- a/pyomo/dae/tests/test_misc.py
+++ b/pyomo/dae/tests/test_misc.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/dae/tests/test_set_utils.py b/pyomo/dae/tests/test_set_utils.py
index fa592e05181..8877dadf798 100644
--- a/pyomo/dae/tests/test_set_utils.py
+++ b/pyomo/dae/tests/test_set_utils.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/dae/tests/test_simulator.py b/pyomo/dae/tests/test_simulator.py
index e79bc7b23b6..76316b5571e 100644
--- a/pyomo/dae/tests/test_simulator.py
+++ b/pyomo/dae/tests/test_simulator.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/dae/utilities.py b/pyomo/dae/utilities.py
index e48c66e003d..ae4018a122e 100644
--- a/pyomo/dae/utilities.py
+++ b/pyomo/dae/utilities.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/dataportal/DataPortal.py b/pyomo/dataportal/DataPortal.py
index 8eb577af013..457bb1aacee 100644
--- a/pyomo/dataportal/DataPortal.py
+++ b/pyomo/dataportal/DataPortal.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,8 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['DataPortal']
-
 import logging
 from pyomo.common.log import is_debug_set
 from pyomo.dataportal.factory import DataManagerFactory, UnknownDataManager
diff --git a/pyomo/dataportal/TableData.py b/pyomo/dataportal/TableData.py
index 1d428967449..f1500d09f9b 100644
--- a/pyomo/dataportal/TableData.py
+++ b/pyomo/dataportal/TableData.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,8 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['TableData']
-
 from pyomo.common.collections import Bunch
 from pyomo.dataportal.process_data import _process_data
 
diff --git a/pyomo/dataportal/__init__.py b/pyomo/dataportal/__init__.py
index ca82614ef2a..ece0ac039f6 100644
--- a/pyomo/dataportal/__init__.py
+++ b/pyomo/dataportal/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/dataportal/factory.py b/pyomo/dataportal/factory.py
index f1c18dc05c9..479769137e2 100644
--- a/pyomo/dataportal/factory.py
+++ b/pyomo/dataportal/factory.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,8 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['DataManagerFactory', 'UnknownDataManager']
-
 import logging
 from pyomo.common import Factory
 from pyomo.common.plugin_base import PluginError
diff --git a/pyomo/dataportal/parse_datacmds.py b/pyomo/dataportal/parse_datacmds.py
index be363fdb64b..60e2f2c0acb 100644
--- a/pyomo/dataportal/parse_datacmds.py
+++ b/pyomo/dataportal/parse_datacmds.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,8 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['parse_data_commands']
-
 import bisect
 import sys
 import logging
diff --git a/pyomo/dataportal/plugins/__init__.py b/pyomo/dataportal/plugins/__init__.py
index c3387af9d1e..3a356ee9da8 100644
--- a/pyomo/dataportal/plugins/__init__.py
+++ b/pyomo/dataportal/plugins/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/dataportal/plugins/csv_table.py b/pyomo/dataportal/plugins/csv_table.py
index 6563a89df10..a52c8227695 100644
--- a/pyomo/dataportal/plugins/csv_table.py
+++ b/pyomo/dataportal/plugins/csv_table.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/dataportal/plugins/datacommands.py b/pyomo/dataportal/plugins/datacommands.py
index 068a551d8d2..2da0d44f048 100644
--- a/pyomo/dataportal/plugins/datacommands.py
+++ b/pyomo/dataportal/plugins/datacommands.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/dataportal/plugins/db_table.py b/pyomo/dataportal/plugins/db_table.py
index 682b87ab13e..71fd499f725 100644
--- a/pyomo/dataportal/plugins/db_table.py
+++ b/pyomo/dataportal/plugins/db_table.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -385,8 +385,9 @@ def __init__(self, filename=None, data=None):
         will override that in the file.
         """
 
-        # ugh hardcoded strings. See following URL for info:
-        # http://publib.boulder.ibm.com/infocenter/idshelp/v10/index.jsp?topic=/com.ibm.odbc.doc/odbc58.htm
+        # Hardcoded string required here.
+        # See documentation:
+        # https://www.ibm.com/docs/en/informix-servers/12.10?topic=SSGU8G_12.1.0/com.ibm.odbc.doc/ids_odbc_062.html
         self.ODBC_DS_KEY = 'ODBC Data Sources'
         self.ODBC_INFO_KEY = 'ODBC'
 
diff --git a/pyomo/dataportal/plugins/json_dict.py b/pyomo/dataportal/plugins/json_dict.py
index e42c040ad0b..8b41e9a1c7b 100644
--- a/pyomo/dataportal/plugins/json_dict.py
+++ b/pyomo/dataportal/plugins/json_dict.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/dataportal/plugins/sheet.py b/pyomo/dataportal/plugins/sheet.py
index 8672b9917da..773cce81116 100644
--- a/pyomo/dataportal/plugins/sheet.py
+++ b/pyomo/dataportal/plugins/sheet.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/dataportal/plugins/text.py b/pyomo/dataportal/plugins/text.py
index a9b169e27bd..9a86fd4481b 100644
--- a/pyomo/dataportal/plugins/text.py
+++ b/pyomo/dataportal/plugins/text.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/dataportal/plugins/xml_table.py b/pyomo/dataportal/plugins/xml_table.py
index 79245c6d24a..7e10b96312e 100644
--- a/pyomo/dataportal/plugins/xml_table.py
+++ b/pyomo/dataportal/plugins/xml_table.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/dataportal/process_data.py b/pyomo/dataportal/process_data.py
index 5eb15269e0c..f6f20d69f67 100644
--- a/pyomo/dataportal/process_data.py
+++ b/pyomo/dataportal/process_data.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/dataportal/tests/__init__.py b/pyomo/dataportal/tests/__init__.py
index 65e82b81c0c..85ece8d8cd5 100644
--- a/pyomo/dataportal/tests/__init__.py
+++ b/pyomo/dataportal/tests/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/dataportal/tests/test_dat_parser.py b/pyomo/dataportal/tests/test_dat_parser.py
index 0663279875d..43bf216525c 100644
--- a/pyomo/dataportal/tests/test_dat_parser.py
+++ b/pyomo/dataportal/tests/test_dat_parser.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/dataportal/tests/test_dataportal.py b/pyomo/dataportal/tests/test_dataportal.py
index 3171a118118..8496a8fa3f8 100644
--- a/pyomo/dataportal/tests/test_dataportal.py
+++ b/pyomo/dataportal/tests/test_dataportal.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/duality/__init__.py b/pyomo/duality/__init__.py
index 7f1c869670d..a08ca813ff8 100644
--- a/pyomo/duality/__init__.py
+++ b/pyomo/duality/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/duality/collect.py b/pyomo/duality/collect.py
index a8b62cb8dfe..350ca058f82 100644
--- a/pyomo/duality/collect.py
+++ b/pyomo/duality/collect.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/duality/lagrangian_dual.py b/pyomo/duality/lagrangian_dual.py
index 1b27a3f93d4..96bc3f4a95e 100644
--- a/pyomo/duality/lagrangian_dual.py
+++ b/pyomo/duality/lagrangian_dual.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/duality/plugins.py b/pyomo/duality/plugins.py
index c8c84153975..0e89857ded1 100644
--- a/pyomo/duality/plugins.py
+++ b/pyomo/duality/plugins.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/duality/tests/__init__.py b/pyomo/duality/tests/__init__.py
index 0dc08cc5aea..761a6e6c44c 100644
--- a/pyomo/duality/tests/__init__.py
+++ b/pyomo/duality/tests/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/duality/tests/test_linear_dual.py b/pyomo/duality/tests/test_linear_dual.py
index ba3554bdc50..da8ba7a370c 100644
--- a/pyomo/duality/tests/test_linear_dual.py
+++ b/pyomo/duality/tests/test_linear_dual.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/environ/__init__.py b/pyomo/environ/__init__.py
index 51c68449247..07b3dfad680 100644
--- a/pyomo/environ/__init__.py
+++ b/pyomo/environ/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -50,6 +50,8 @@ def _do_import(pkg_name):
     'pyomo.contrib.multistart',
     'pyomo.contrib.preprocessing',
     'pyomo.contrib.pynumero',
+    'pyomo.contrib.simplification',
+    'pyomo.contrib.solver',
     'pyomo.contrib.trustregion',
 ]
 
@@ -114,6 +116,8 @@ def _import_packages():
     exactly,
     atleast,
     atmost,
+    all_different,
+    count_if,
     implies,
     lnot,
     xor,
diff --git a/pyomo/environ/tests/__init__.py b/pyomo/environ/tests/__init__.py
index b1d721839c7..61e159c169b 100644
--- a/pyomo/environ/tests/__init__.py
+++ b/pyomo/environ/tests/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/environ/tests/standalone_minimal_pyomo_driver.py b/pyomo/environ/tests/standalone_minimal_pyomo_driver.py
index 88f8e9f8651..80fb5d15121 100644
--- a/pyomo/environ/tests/standalone_minimal_pyomo_driver.py
+++ b/pyomo/environ/tests/standalone_minimal_pyomo_driver.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/environ/tests/test_environ.py b/pyomo/environ/tests/test_environ.py
index b223ba0e916..9811b412af7 100644
--- a/pyomo/environ/tests/test_environ.py
+++ b/pyomo/environ/tests/test_environ.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -140,6 +140,7 @@ def test_tpl_import_time(self):
             'cPickle',
             'csv',
             'ctypes',  # mandatory import in core/base/external.py; TODO: fix this
+            'datetime',  # imported by contrib.solver
             'decimal',
             'gc',  # Imported on MacOS, Windows; Linux in 3.10
             'glob',
diff --git a/pyomo/environ/tests/test_package_layout.py b/pyomo/environ/tests/test_package_layout.py
index 0bc8c55113a..47c6422a879 100644
--- a/pyomo/environ/tests/test_package_layout.py
+++ b/pyomo/environ/tests/test_package_layout.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -38,6 +38,7 @@
 _NON_MODULE_DIRS = {
     join('contrib', 'ampl_function_demo', 'src'),
     join('contrib', 'appsi', 'cmodel', 'src'),
+    join('contrib', 'simplification', 'ginac', 'src'),
     join('contrib', 'pynumero', 'src'),
     join('core', 'tests', 'data', 'baselines'),
     join('core', 'tests', 'diet', 'baselines'),
diff --git a/pyomo/gdp/__init__.py b/pyomo/gdp/__init__.py
index 6fc2d4b7351..d204369cdba 100644
--- a/pyomo/gdp/__init__.py
+++ b/pyomo/gdp/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,7 +9,13 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-from pyomo.gdp.disjunct import GDP_Error, Disjunct, Disjunction
+from pyomo.gdp.disjunct import (
+    GDP_Error,
+    Disjunct,
+    DisjunctData,
+    Disjunction,
+    DisjunctionData,
+)
 
 # Do not import these files: importing them registers the transformation
 # plugins with the pyomo script so that they get automatically invoked.
diff --git a/pyomo/gdp/basic_step.py b/pyomo/gdp/basic_step.py
index 69313ac2b1b..56a19e2a0f2 100644
--- a/pyomo/gdp/basic_step.py
+++ b/pyomo/gdp/basic_step.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/gdp/disjunct.py b/pyomo/gdp/disjunct.py
index eca6d93d732..637f55cbed1 100644
--- a/pyomo/gdp/disjunct.py
+++ b/pyomo/gdp/disjunct.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -41,7 +41,7 @@
     ComponentData,
 )
 from pyomo.core.base.global_set import UnindexedComponent_index
-from pyomo.core.base.block import _BlockData
+from pyomo.core.base.block import BlockData
 from pyomo.core.base.misc import apply_indexed_rule
 from pyomo.core.base.indexed_component import ActiveIndexedComponent
 from pyomo.core.expr.expr_common import ExpressionType
@@ -412,7 +412,7 @@ def process(arg):
             return (_Initializer.deferred_value, arg)
 
 
-class _DisjunctData(_BlockData):
+class DisjunctData(BlockData):
     __autoslot_mappers__ = {'_transformation_block': AutoSlots.weakref_mapper}
 
     _Block_reserved_words = set()
@@ -424,7 +424,7 @@ def transformation_block(self):
         )
 
     def __init__(self, component):
-        _BlockData.__init__(self, component)
+        BlockData.__init__(self, component)
         with self._declare_reserved_components():
             self.indicator_var = AutoLinkedBooleanVar()
             self.binary_indicator_var = AutoLinkedBinaryVar(self.indicator_var)
@@ -434,23 +434,28 @@ def __init__(self, component):
         self._transformation_block = None
 
     def activate(self):
-        super(_DisjunctData, self).activate()
+        super(DisjunctData, self).activate()
         self.indicator_var.unfix()
 
     def deactivate(self):
-        super(_DisjunctData, self).deactivate()
+        super(DisjunctData, self).deactivate()
         self.indicator_var.fix(False)
 
     def _deactivate_without_fixing_indicator(self):
-        super(_DisjunctData, self).deactivate()
+        super(DisjunctData, self).deactivate()
 
     def _activate_without_unfixing_indicator(self):
-        super(_DisjunctData, self).activate()
+        super(DisjunctData, self).activate()
+
+
+class _DisjunctData(metaclass=RenamedClass):
+    __renamed__new_class__ = DisjunctData
+    __renamed__version__ = '6.7.2'
 
 
 @ModelComponentFactory.register("Disjunctive blocks.")
 class Disjunct(Block):
-    _ComponentDataClass = _DisjunctData
+    _ComponentDataClass = DisjunctData
 
     def __new__(cls, *args, **kwds):
         if cls != Disjunct:
@@ -475,7 +480,7 @@ def __init__(self, *args, **kwargs):
     # def _deactivate_without_fixing_indicator(self):
     #    # Ideally, this would be a super call from this class.  However,
     #    # doing that would trigger a call to deactivate() on all the
-    #    # _DisjunctData objects (exactly what we want to avoid!)
+    #    # DisjunctData objects (exactly what we want to avoid!)
     #    #
     #    # For the time being, we will do something bad and directly call
     #    # the base class method from where we would otherwise want to
@@ -484,7 +489,7 @@ def __init__(self, *args, **kwargs):
     def _activate_without_unfixing_indicator(self):
         # Ideally, this would be a super call from this class.  However,
         # doing that would trigger a call to deactivate() on all the
-        # _DisjunctData objects (exactly what we want to avoid!)
+        # DisjunctData objects (exactly what we want to avoid!)
         #
         # For the time being, we will do something bad and directly call
         # the base class method from where we would otherwise want to
@@ -495,15 +500,15 @@ def _activate_without_unfixing_indicator(self):
                 component_data._activate_without_unfixing_indicator()
 
 
-class ScalarDisjunct(_DisjunctData, Disjunct):
+class ScalarDisjunct(DisjunctData, Disjunct):
     def __init__(self, *args, **kwds):
         ## FIXME: This is a HACK to get around a chicken-and-egg issue
-        ## where _BlockData creates the indicator_var *before*
+        ## where BlockData creates the indicator_var *before*
         ## Block.__init__ declares the _defer_construction flag.
         self._defer_construction = True
         self._suppress_ctypes = set()
 
-        _DisjunctData.__init__(self, self)
+        DisjunctData.__init__(self, self)
         Disjunct.__init__(self, *args, **kwds)
         self._data[None] = self
         self._index = UnindexedComponent_index
@@ -524,10 +529,10 @@ def active(self):
         return any(d.active for d in self._data.values())
 
 
-_DisjunctData._Block_reserved_words = set(dir(Disjunct()))
+DisjunctData._Block_reserved_words = set(dir(Disjunct()))
 
 
-class _DisjunctionData(ActiveComponentData):
+class DisjunctionData(ActiveComponentData):
     __slots__ = ('disjuncts', 'xor', '_algebraic_constraint', '_transformation_map')
     __autoslot_mappers__ = {'_algebraic_constraint': AutoSlots.weakref_mapper}
     _NoArgument = (0,)
@@ -542,7 +547,7 @@ def __init__(self, component=None):
         #
         # These lines represent in-lining of the
         # following constructors:
-        #   - _ConstraintData,
+        #   - ConstraintData,
         #   - ActiveComponentData
         #   - ComponentData
         self._component = weakref_ref(component) if (component is not None) else None
@@ -620,9 +625,14 @@ def set_value(self, expr):
             self.disjuncts.append(disjunct)
 
 
+class _DisjunctionData(metaclass=RenamedClass):
+    __renamed__new_class__ = DisjunctionData
+    __renamed__version__ = '6.7.2'
+
+
 @ModelComponentFactory.register("Disjunction expressions.")
 class Disjunction(ActiveIndexedComponent):
-    _ComponentDataClass = _DisjunctionData
+    _ComponentDataClass = DisjunctionData
 
     def __new__(cls, *args, **kwds):
         if cls != Disjunction:
@@ -700,6 +710,10 @@ def construct(self, data=None):
         timer = ConstructionTimer(self)
         self._constructed = True
 
+        if self._anonymous_sets is not None:
+            for _set in self._anonymous_sets:
+                _set.construct()
+
         _self_parent = self.parent_block()
         if not self.is_indexed():
             if self._init_rule is not None:
@@ -759,9 +773,9 @@ def _pprint(self):
         )
 
 
-class ScalarDisjunction(_DisjunctionData, Disjunction):
+class ScalarDisjunction(DisjunctionData, Disjunction):
     def __init__(self, *args, **kwds):
-        _DisjunctionData.__init__(self, component=self)
+        DisjunctionData.__init__(self, component=self)
         Disjunction.__init__(self, *args, **kwds)
         self._index = UnindexedComponent_index
 
@@ -772,7 +786,7 @@ def __init__(self, *args, **kwds):
     # currently in place). So during initialization only, we will
     # treat them as "indexed" objects where things like
     # Constraint.Skip are managed. But after that they will behave
-    # like _DisjunctionData objects where set_value does not handle
+    # like DisjunctionData objects where set_value does not handle
     # Disjunction.Skip but expects a valid expression or None.
     #
 
diff --git a/pyomo/gdp/plugins/__init__.py b/pyomo/gdp/plugins/__init__.py
index 1222ce500f1..875e47e6cc1 100644
--- a/pyomo/gdp/plugins/__init__.py
+++ b/pyomo/gdp/plugins/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -22,3 +22,4 @@ def load():
     import pyomo.gdp.plugins.multiple_bigm
     import pyomo.gdp.plugins.transform_current_disjunctive_state
     import pyomo.gdp.plugins.bound_pretransformation
+    import pyomo.gdp.plugins.binary_multiplication
diff --git a/pyomo/gdp/plugins/between_steps.py b/pyomo/gdp/plugins/between_steps.py
index fad783d595d..8f57164334e 100644
--- a/pyomo/gdp/plugins/between_steps.py
+++ b/pyomo/gdp/plugins/between_steps.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/gdp/plugins/bigm.py b/pyomo/gdp/plugins/bigm.py
index e554d5593ab..d715d913db8 100644
--- a/pyomo/gdp/plugins/bigm.py
+++ b/pyomo/gdp/plugins/bigm.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -13,6 +13,7 @@
 
 import logging
 
+from pyomo.common.autoslots import AutoSlots
 from pyomo.common.collections import ComponentMap
 from pyomo.common.config import ConfigDict, ConfigValue
 from pyomo.common.gc_manager import PauseGC
@@ -58,6 +59,26 @@
 logger = logging.getLogger('pyomo.gdp.bigm')
 
 
+class _BigMData(AutoSlots.Mixin):
+    __slots__ = ('bigm_src',)
+
+    def __init__(self):
+        # we will keep a map of constraints (hashable, ha!) to a tuple to
+        # indicate what their M value is and where it came from, of the form:
+        # ((lower_value, lower_source, lower_key), (upper_value, upper_source,
+        # upper_key)), where the first tuple is the information for the lower M,
+        # the second tuple is the info for the upper M, source is the Suffix or
+        # argument dictionary and None if the value was calculated, and key is
+        # the key in the Suffix or argument dictionary, and None if it was
+        # calculated. (Note that it is possible the lower or upper is
+        # user-specified and the other is not, hence the need to store
+        # information for both.)
+        self.bigm_src = {}
+
+
+Block.register_private_data_initializer(_BigMData)
+
+
 @TransformationFactory.register(
     'gdp.bigm', doc="Relax disjunctive model using big-M terms."
 )
@@ -94,15 +115,8 @@ class BigM_Transformation(GDP_to_MIP_Transformation, _BigM_MixIn):
     name beginning "_pyomo_gdp_bigm_reformulation".  That Block will
     contain an indexed Block named "relaxedDisjuncts", which will hold
     the relaxed disjuncts.  This block is indexed by an integer
-    indicating the order in which the disjuncts were relaxed.
-    Each block has a dictionary "_constraintMap":
-
-        'srcConstraints': ComponentMap(<transformed constraint>:
-                                       <src constraint>)
-        'transformedConstraints': ComponentMap(<src constraint>:
-                                               <transformed constraint>)
-
-    All transformed Disjuncts will have a pointer to the block their transformed
+    indicating the order in which the disjuncts were relaxed. All
+    transformed Disjuncts will have a pointer to the block their transformed
     constraints are on, and all transformed Disjunctions will have a
     pointer to the corresponding 'Or' or 'ExactlyOne' constraint.
 
@@ -199,21 +213,15 @@ def _apply_to_impl(self, instance, **kwds):
         bigM = self._config.bigM
         for t in preprocessed_targets:
             if t.ctype is Disjunction:
-                self._transform_disjunctionData(
-                    t,
-                    t.index(),
-                    bigM,
-                    parent_disjunct=gdp_tree.parent(t),
-                    root_disjunct=gdp_tree.root_disjunct(t),
-                )
+                self._transform_disjunctionData(t, t.index(), bigM, gdp_tree)
 
         # issue warnings about anything that was in the bigM args dict that we
         # didn't use
         _warn_for_unused_bigM_args(bigM, self.used_args, logger)
 
-    def _transform_disjunctionData(
-        self, obj, index, bigM, parent_disjunct=None, root_disjunct=None
-    ):
+    def _transform_disjunctionData(self, obj, index, bigM, gdp_tree):
+        parent_disjunct = gdp_tree.parent(obj)
+        root_disjunct = gdp_tree.root_disjunct(obj)
         (transBlock, xorConstraint) = self._setup_transform_disjunctionData(
             obj, root_disjunct
         )
@@ -222,13 +230,12 @@ def _transform_disjunctionData(
         or_expr = 0
         for disjunct in obj.disjuncts:
             or_expr += disjunct.binary_indicator_var
-            self._transform_disjunct(disjunct, bigM, transBlock)
+            self._transform_disjunct(disjunct, bigM, transBlock, gdp_tree)
 
-        rhs = 1 if parent_disjunct is None else parent_disjunct.binary_indicator_var
         if obj.xor:
-            xorConstraint[index] = or_expr == rhs
+            xorConstraint[index] = or_expr == 1
         else:
-            xorConstraint[index] = or_expr >= rhs
+            xorConstraint[index] = or_expr >= 1
         # Mark the DisjunctionData as transformed by mapping it to its XOR
         # constraint.
         obj._algebraic_constraint = weakref_ref(xorConstraint[index])
@@ -236,7 +243,7 @@ def _transform_disjunctionData(
         # and deactivate for the writers
         obj.deactivate()
 
-    def _transform_disjunct(self, obj, bigM, transBlock):
+    def _transform_disjunct(self, obj, bigM, transBlock, gdp_tree):
         # We're not using the preprocessed list here, so this could be
         # inactive. We've already done the error checking in preprocessing, so
         # we just skip it here.
@@ -248,17 +255,11 @@ def _transform_disjunct(self, obj, bigM, transBlock):
 
         relaxationBlock = self._get_disjunct_transformation_block(obj, transBlock)
 
-        # we will keep a map of constraints (hashable, ha!) to a tuple to
-        # indicate what their M value is and where it came from, of the form:
-        # ((lower_value, lower_source, lower_key), (upper_value, upper_source,
-        # upper_key)), where the first tuple is the information for the lower M,
-        # the second tuple is the info for the upper M, source is the Suffix or
-        # argument dictionary and None if the value was calculated, and key is
-        # the key in the Suffix or argument dictionary, and None if it was
-        # calculated. (Note that it is possible the lower or upper is
-        # user-specified and the other is not, hence the need to store
-        # information for both.)
-        relaxationBlock.bigm_src = {}
+        indicator_expression = 0
+        node = obj
+        while node is not None:
+            indicator_expression += 1 - node.binary_indicator_var
+            node = gdp_tree.parent_disjunct(node)
 
         # This is crazy, but if the disjunction has been previously
         # relaxed, the disjunct *could* be deactivated.  This is a big
@@ -269,18 +270,26 @@ def _transform_disjunct(self, obj, bigM, transBlock):
         # comparing the two relaxations.
         #
         # Transform each component within this disjunct
-        self._transform_block_components(obj, obj, bigM, arg_list, suffix_list)
+        self._transform_block_components(
+            obj, obj, bigM, arg_list, suffix_list, indicator_expression
+        )
 
         # deactivate disjunct to keep the writers happy
         obj._deactivate_without_fixing_indicator()
 
     def _transform_constraint(
-        self, obj, disjunct, bigMargs, arg_list, disjunct_suffix_list
+        self,
+        obj,
+        disjunct,
+        bigMargs,
+        arg_list,
+        disjunct_suffix_list,
+        indicator_expression,
     ):
         # add constraint to the transformation block, we'll transform it there.
         transBlock = disjunct._transformation_block()
-        bigm_src = transBlock.bigm_src
-        constraintMap = transBlock._constraintMap
+        bigm_src = transBlock.private_data().bigm_src
+        constraint_map = transBlock.private_data('pyomo.gdp')
 
         disjunctionRelaxationBlock = transBlock.parent_block()
 
@@ -347,7 +356,13 @@ def _transform_constraint(
             bigm_src[c] = (lower, upper)
 
             self._add_constraint_expressions(
-                c, i, M, disjunct.binary_indicator_var, newConstraint, constraintMap
+                c,
+                i,
+                M,
+                disjunct.binary_indicator_var,
+                newConstraint,
+                constraint_map,
+                indicator_expression=indicator_expression,
             )
 
             # deactivate because we relaxed
@@ -410,7 +425,7 @@ def _update_M_from_suffixes(self, constraint, suffix_list, lower, upper):
     def get_m_value_src(self, constraint):
         transBlock = _get_constraint_transBlock(constraint)
         ((lower_val, lower_source, lower_key), (upper_val, upper_source, upper_key)) = (
-            transBlock.bigm_src[constraint]
+            transBlock.private_data().bigm_src[constraint]
         )
 
         if (
@@ -465,7 +480,7 @@ def get_M_value_src(self, constraint):
         transBlock = _get_constraint_transBlock(constraint)
         # This is a KeyError if it fails, but it is also my fault if it
         # fails... (That is, it's a bug in the mapping.)
-        return transBlock.bigm_src[constraint]
+        return transBlock.private_data().bigm_src[constraint]
 
     def get_M_value(self, constraint):
         """Returns the M values used to transform constraint. Return is a tuple:
@@ -480,7 +495,7 @@ def get_M_value(self, constraint):
         transBlock = _get_constraint_transBlock(constraint)
         # This is a KeyError if it fails, but it is also my fault if it
         # fails... (That is, it's a bug in the mapping.)
-        lower, upper = transBlock.bigm_src[constraint]
+        lower, upper = transBlock.private_data().bigm_src[constraint]
         return (lower[0], upper[0])
 
     def get_all_M_values_by_constraint(self, model):
@@ -500,9 +515,8 @@ def get_all_M_values_by_constraint(self, model):
             # First check if it was transformed at all.
             if transBlock is not None:
                 # If it was transformed with BigM, we get the M values.
-                if hasattr(transBlock, 'bigm_src'):
-                    for cons in transBlock.bigm_src:
-                        m_values[cons] = self.get_M_value(cons)
+                for cons in transBlock.private_data().bigm_src:
+                    m_values[cons] = self.get_M_value(cons)
         return m_values
 
     def get_largest_M_value(self, model):
diff --git a/pyomo/gdp/plugins/bigm_mixin.py b/pyomo/gdp/plugins/bigm_mixin.py
index a4df641c8c6..1c3fcb2c64a 100644
--- a/pyomo/gdp/plugins/bigm_mixin.py
+++ b/pyomo/gdp/plugins/bigm_mixin.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -232,7 +232,14 @@ def _estimate_M(self, expr, constraint):
         return tuple(M)
 
     def _add_constraint_expressions(
-        self, c, i, M, indicator_var, newConstraint, constraintMap
+        self,
+        c,
+        i,
+        M,
+        indicator_var,
+        newConstraint,
+        constraint_map,
+        indicator_expression=None,
     ):
         # Since we are both combining components from multiple blocks and using
         # local names, we need to make sure that the first index for
@@ -244,6 +251,8 @@ def _add_constraint_expressions(
         # over the constraint indices, but I don't think it matters a lot.)
         unique = len(newConstraint)
         name = c.local_name + "_%s" % unique
+        if indicator_expression is None:
+            indicator_expression = 1 - indicator_var
 
         if c.lower is not None:
             if M[0] is None:
@@ -251,25 +260,21 @@ def _add_constraint_expressions(
                     "Cannot relax disjunctive constraint '%s' "
                     "because M is not defined." % name
                 )
-            M_expr = M[0] * (1 - indicator_var)
+            M_expr = M[0] * indicator_expression
             newConstraint.add((name, i, 'lb'), c.lower <= c.body - M_expr)
-            constraintMap['transformedConstraints'][c] = [newConstraint[name, i, 'lb']]
-            constraintMap['srcConstraints'][newConstraint[name, i, 'lb']] = c
+            constraint_map.transformed_constraints[c].append(
+                newConstraint[name, i, 'lb']
+            )
+            constraint_map.src_constraint[newConstraint[name, i, 'lb']] = c
         if c.upper is not None:
             if M[1] is None:
                 raise GDP_Error(
                     "Cannot relax disjunctive constraint '%s' "
                     "because M is not defined." % name
                 )
-            M_expr = M[1] * (1 - indicator_var)
+            M_expr = M[1] * indicator_expression
             newConstraint.add((name, i, 'ub'), c.body - M_expr <= c.upper)
-            transformed = constraintMap['transformedConstraints'].get(c)
-            if transformed is not None:
-                constraintMap['transformedConstraints'][c].append(
-                    newConstraint[name, i, 'ub']
-                )
-            else:
-                constraintMap['transformedConstraints'][c] = [
-                    newConstraint[name, i, 'ub']
-                ]
-            constraintMap['srcConstraints'][newConstraint[name, i, 'ub']] = c
+            constraint_map.transformed_constraints[c].append(
+                newConstraint[name, i, 'ub']
+            )
+            constraint_map.src_constraint[newConstraint[name, i, 'ub']] = c
diff --git a/pyomo/gdp/plugins/bilinear.py b/pyomo/gdp/plugins/bilinear.py
index feacaaddefc..67390801348 100644
--- a/pyomo/gdp/plugins/bilinear.py
+++ b/pyomo/gdp/plugins/bilinear.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/gdp/plugins/binary_multiplication.py b/pyomo/gdp/plugins/binary_multiplication.py
new file mode 100644
index 00000000000..bea33580ed6
--- /dev/null
+++ b/pyomo/gdp/plugins/binary_multiplication.py
@@ -0,0 +1,176 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+from .gdp_to_mip_transformation import GDP_to_MIP_Transformation
+from pyomo.common.config import ConfigDict, ConfigValue
+from pyomo.core.base import TransformationFactory
+from pyomo.core.util import target_list
+from pyomo.gdp import Disjunction
+from weakref import ref as weakref_ref
+import logging
+
+
+logger = logging.getLogger(__name__)
+
+
+@TransformationFactory.register(
+    'gdp.binary_multiplication',
+    doc="Reformulate the GDP as an MINLP by multiplying f(x) <= 0 by y to get "
+    "f(x) * y <= 0 where y is the binary corresponding to the Boolean indicator "
+    "var of the Disjunct containing f(x) <= 0.",
+)
+class GDPBinaryMultiplicationTransformation(GDP_to_MIP_Transformation):
+    CONFIG = ConfigDict("gdp.binary_multiplication")
+    CONFIG.declare(
+        'targets',
+        ConfigValue(
+            default=None,
+            domain=target_list,
+            description="target or list of targets that will be transformed",
+            doc="""
+
+        This specifies the list of components to transform. If None (default), the
+        entire model is transformed. Note that if the transformation is done out
+        of place, the list of targets should be attached to the model before it
+        is cloned, and the list will specify the targets on the cloned
+        instance.""",
+        ),
+    )
+
+    transformation_name = 'binary_multiplication'
+
+    def __init__(self):
+        super().__init__(logger)
+
+    def _apply_to(self, instance, **kwds):
+        try:
+            self._apply_to_impl(instance, **kwds)
+        finally:
+            self._restore_state()
+
+    def _apply_to_impl(self, instance, **kwds):
+        self._process_arguments(instance, **kwds)
+
+        # filter out inactive targets and handle case where targets aren't
+        # specified.
+        targets = self._filter_targets(instance)
+        # transform logical constraints based on targets
+        self._transform_logical_constraints(instance, targets)
+        # we need to preprocess targets to make sure that if there are any
+        # disjunctions in targets that their disjuncts appear before them in
+        # the list.
+        gdp_tree = self._get_gdp_tree_from_targets(instance, targets)
+        preprocessed_targets = gdp_tree.reverse_topological_sort()
+
+        for t in preprocessed_targets:
+            if t.ctype is Disjunction:
+                self._transform_disjunctionData(
+                    t,
+                    t.index(),
+                    parent_disjunct=gdp_tree.parent(t),
+                    root_disjunct=gdp_tree.root_disjunct(t),
+                )
+
+    def _transform_disjunctionData(
+        self, obj, index, parent_disjunct=None, root_disjunct=None
+    ):
+        (transBlock, xorConstraint) = self._setup_transform_disjunctionData(
+            obj, root_disjunct
+        )
+
+        # add or (or xor) constraint
+        or_expr = 0
+        for disjunct in obj.disjuncts:
+            or_expr += disjunct.binary_indicator_var
+            self._transform_disjunct(disjunct, transBlock)
+
+        if obj.xor:
+            xorConstraint[index] = or_expr == 1
+        else:
+            xorConstraint[index] = or_expr >= 1
+        # Mark the DisjunctionData as transformed by mapping it to its XOR
+        # constraint.
+        obj._algebraic_constraint = weakref_ref(xorConstraint[index])
+
+        # and deactivate for the writers
+        obj.deactivate()
+
+    def _transform_disjunct(self, obj, transBlock):
+        # We're not using the preprocessed list here, so this could be
+        # inactive. We've already done the error checking in preprocessing, so
+        # we just skip it here.
+        if not obj.active:
+            return
+
+        relaxationBlock = self._get_disjunct_transformation_block(obj, transBlock)
+
+        # Transform each component within this disjunct
+        self._transform_block_components(obj, obj)
+
+        # deactivate disjunct to keep the writers happy
+        obj._deactivate_without_fixing_indicator()
+
+    def _transform_constraint(self, obj, disjunct):
+        # add constraint to the transformation block, we'll transform it there.
+        transBlock = disjunct._transformation_block()
+        constraint_map = transBlock.private_data('pyomo.gdp')
+
+        disjunctionRelaxationBlock = transBlock.parent_block()
+
+        # We will make indexes from ({obj.local_name} x obj.index_set() x ['lb',
+        # 'ub']), but don't bother construct that set here, as taking Cartesian
+        # products is kind of expensive (and redundant since we have the
+        # original model)
+        newConstraint = transBlock.transformedConstraints
+
+        for i in sorted(obj.keys()):
+            c = obj[i]
+            if not c.active:
+                continue
+
+            self._add_constraint_expressions(
+                c, i, disjunct.binary_indicator_var, newConstraint, constraint_map
+            )
+
+            # deactivate because we relaxed
+            c.deactivate()
+
+    def _add_constraint_expressions(
+        self, c, i, indicator_var, newConstraint, constraint_map
+    ):
+        # Since we are both combining components from multiple blocks and using
+        # local names, we need to make sure that the first index for
+        # transformedConstraints is guaranteed to be unique. We just grab the
+        # current length of the list here since that will be monotonically
+        # increasing and hence unique. We'll append it to the
+        # slightly-more-human-readable constraint name for something familiar
+        # but unique. (Note that we really could do this outside of the loop
+        # over the constraint indices, but I don't think it matters a lot.)
+        unique = len(newConstraint)
+        name = c.local_name + "_%s" % unique
+        transformed = constraint_map.transformed_constraints[c]
+
+        lb, ub = c.lower, c.upper
+        if (c.equality or lb is ub) and lb is not None:
+            # equality
+            newConstraint.add((name, i, 'eq'), (c.body - lb) * indicator_var == 0)
+            transformed.append(newConstraint[name, i, 'eq'])
+            constraint_map.src_constraint[newConstraint[name, i, 'eq']] = c
+        else:
+            # inequality
+            if lb is not None:
+                newConstraint.add((name, i, 'lb'), 0 <= (c.body - lb) * indicator_var)
+                transformed.append(newConstraint[name, i, 'lb'])
+                constraint_map.src_constraint[newConstraint[name, i, 'lb']] = c
+            if ub is not None:
+                newConstraint.add((name, i, 'ub'), (c.body - ub) * indicator_var <= 0)
+                transformed.append(newConstraint[name, i, 'ub'])
+                constraint_map.src_constraint[newConstraint[name, i, 'ub']] = c
diff --git a/pyomo/gdp/plugins/bound_pretransformation.py b/pyomo/gdp/plugins/bound_pretransformation.py
index 56a39115f34..7c90c24d869 100644
--- a/pyomo/gdp/plugins/bound_pretransformation.py
+++ b/pyomo/gdp/plugins/bound_pretransformation.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/gdp/plugins/chull.py b/pyomo/gdp/plugins/chull.py
index d226c57aae7..c11d8ea0729 100644
--- a/pyomo/gdp/plugins/chull.py
+++ b/pyomo/gdp/plugins/chull.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/gdp/plugins/cuttingplane.py b/pyomo/gdp/plugins/cuttingplane.py
index 7a6a927a316..6c77a582987 100644
--- a/pyomo/gdp/plugins/cuttingplane.py
+++ b/pyomo/gdp/plugins/cuttingplane.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/gdp/plugins/fix_disjuncts.py b/pyomo/gdp/plugins/fix_disjuncts.py
index d0f59ce87ce..172363caab7 100644
--- a/pyomo/gdp/plugins/fix_disjuncts.py
+++ b/pyomo/gdp/plugins/fix_disjuncts.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -52,7 +52,7 @@ class GDP_Disjunct_Fixer(Transformation):
 
     This reclassifies all disjuncts in the passed model instance as ctype Block
     and deactivates the constraints and disjunctions within inactive disjuncts.
-    In addition, it transforms relvant LogicalConstraints and BooleanVars so
+    In addition, it transforms relevant LogicalConstraints and BooleanVars so
     that the resulting model is a (MI)(N)LP (where it is only mixed-integer
     if the model contains integer-domain Vars or BooleanVars which were not
     indicator_vars of Disjuncs.
diff --git a/pyomo/gdp/plugins/gdp_to_mip_transformation.py b/pyomo/gdp/plugins/gdp_to_mip_transformation.py
index 0aa5ec163b6..8dcd22b292a 100644
--- a/pyomo/gdp/plugins/gdp_to_mip_transformation.py
+++ b/pyomo/gdp/plugins/gdp_to_mip_transformation.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -11,7 +11,8 @@
 
 from functools import wraps
 
-from pyomo.common.collections import ComponentMap
+from pyomo.common.autoslots import AutoSlots
+from pyomo.common.collections import ComponentMap, DefaultComponentMap
 from pyomo.common.log import is_debug_set
 from pyomo.common.modeling import unique_component_name
 
@@ -48,6 +49,17 @@
 from weakref import ref as weakref_ref
 
 
+class _GDPTransformationData(AutoSlots.Mixin):
+    __slots__ = ('src_constraint', 'transformed_constraints')
+
+    def __init__(self):
+        self.src_constraint = ComponentMap()
+        self.transformed_constraints = DefaultComponentMap(list)
+
+
+Block.register_private_data_initializer(_GDPTransformationData, scope='pyomo.gdp')
+
+
 class GDP_to_MIP_Transformation(Transformation):
     """
     Base class for transformations from GDP to MIP
@@ -213,21 +225,26 @@ def _setup_transform_disjunctionData(self, obj, root_disjunct):
                 "likely indicative of a modeling error." % obj.name
             )
 
-        # Create or fetch the transformation block
+        # We always need to create or fetch a transformation block on the parent block.
+        trans_block, new_block = self._add_transformation_block(obj.parent_block())
+        # This is where we put exactly_one/or constraint
+        algebraic_constraint = self._add_xor_constraint(
+            obj.parent_component(), trans_block
+        )
+
+        # If requested, create or fetch the transformation block above the
+        # nested hierarchy
         if root_disjunct is not None:
-            # We want to put all the transformed things on the root
-            # Disjunct's parent's block so that they do not get
-            # re-transformed
-            transBlock, new_block = self._add_transformation_block(
+            # We want to put some transformed things on the root Disjunct's
+            # parent's block so that they do not get re-transformed. (Note this
+            # is never true for hull, but it calls this method with
+            # root_disjunct=None. BigM can't put the exactly-one constraint up
+            # here, but it can put everything else.)
+            trans_block, new_block = self._add_transformation_block(
                 root_disjunct.parent_block()
             )
-        else:
-            # This isn't nested--just put it on the parent block.
-            transBlock, new_block = self._add_transformation_block(obj.parent_block())
-
-        xorConstraint = self._add_xor_constraint(obj.parent_component(), transBlock)
 
-        return transBlock, xorConstraint
+        return trans_block, algebraic_constraint
 
     def _get_disjunct_transformation_block(self, disjunct, transBlock):
         if disjunct.transformation_block is not None:
@@ -238,14 +255,7 @@ def _get_disjunct_transformation_block(self, disjunct, transBlock):
         relaxationBlock = relaxedDisjuncts[len(relaxedDisjuncts)]
 
         relaxationBlock.transformedConstraints = Constraint(Any)
-
         relaxationBlock.localVarReferences = Block()
-        # add the map that will link back and forth between transformed
-        # constraints and their originals.
-        relaxationBlock._constraintMap = {
-            'srcConstraints': ComponentMap(),
-            'transformedConstraints': ComponentMap(),
-        }
 
         # add mappings to source disjunct (so we'll know we've relaxed)
         disjunct._transformation_block = weakref_ref(relaxationBlock)
diff --git a/pyomo/gdp/plugins/gdp_var_mover.py b/pyomo/gdp/plugins/gdp_var_mover.py
index df659670bf4..7b1df0bb68f 100644
--- a/pyomo/gdp/plugins/gdp_var_mover.py
+++ b/pyomo/gdp/plugins/gdp_var_mover.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -115,7 +115,7 @@ def _apply_to(self, instance, **kwds):
                 disjunct_component, Block
             )
             # HACK: activate the block, but do not activate the
-            # _BlockData objects
+            # BlockData objects
             super(ActiveIndexedComponent, disjunct_component).activate()
 
             # Deactivate all constraints.  Note that we only need to
diff --git a/pyomo/gdp/plugins/hull.py b/pyomo/gdp/plugins/hull.py
index a600ef76bc7..854366c0cf0 100644
--- a/pyomo/gdp/plugins/hull.py
+++ b/pyomo/gdp/plugins/hull.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -11,9 +11,12 @@
 
 import logging
 
+from collections import defaultdict
+
+from pyomo.common.autoslots import AutoSlots
 import pyomo.common.config as cfg
 from pyomo.common import deprecated
-from pyomo.common.collections import ComponentMap, ComponentSet
+from pyomo.common.collections import ComponentMap, ComponentSet, DefaultComponentMap
 from pyomo.common.modeling import unique_component_name
 from pyomo.core.expr.numvalue import ZeroConstant
 import pyomo.core.expr as EXPR
@@ -39,6 +42,7 @@
     Binary,
 )
 from pyomo.gdp import Disjunct, Disjunction, GDP_Error
+from pyomo.gdp.disjunct import DisjunctData
 from pyomo.gdp.plugins.gdp_to_mip_transformation import GDP_to_MIP_Transformation
 from pyomo.gdp.transformed_disjunct import _TransformedDisjunct
 from pyomo.gdp.util import (
@@ -47,11 +51,30 @@
     _warn_for_active_disjunct,
 )
 from pyomo.core.util import target_list
+from pyomo.util.vars_from_expressions import get_vars_from_components
 from weakref import ref as weakref_ref
 
 logger = logging.getLogger('pyomo.gdp.hull')
 
 
+class _HullTransformationData(AutoSlots.Mixin):
+    __slots__ = (
+        'disaggregated_var_map',
+        'original_var_map',
+        'bigm_constraint_map',
+        'disaggregation_constraint_map',
+    )
+
+    def __init__(self):
+        self.disaggregated_var_map = DefaultComponentMap(ComponentMap)
+        self.original_var_map = ComponentMap()
+        self.bigm_constraint_map = DefaultComponentMap(ComponentMap)
+        self.disaggregation_constraint_map = DefaultComponentMap(ComponentMap)
+
+
+Block.register_private_data_initializer(_HullTransformationData)
+
+
 @TransformationFactory.register(
     'gdp.hull', doc="Relax disjunctive model by forming the hull reformulation."
 )
@@ -76,35 +99,13 @@ class Hull_Reformulation(GDP_to_MIP_Transformation):
         list of blocks and Disjunctions [default: the instance]
 
     The transformation will create a new Block with a unique
-    name beginning "_pyomo_gdp_hull_reformulation".
-    The block will have a dictionary "_disaggregatedVarMap:
-        'srcVar': ComponentMap(<src var>:<disaggregated var>),
-        'disaggregatedVar': ComponentMap(<disaggregated var>:<src var>)
-
-    It will also have a ComponentMap "_bigMConstraintMap":
-
-        <disaggregated var>:<bounds constraint>
-
-    Last, it will contain an indexed Block named "relaxedDisjuncts",
-    which will hold the relaxed disjuncts.  This block is indexed by
-    an integer indicating the order in which the disjuncts were relaxed.
-    Each block has a dictionary "_constraintMap":
-
-        'srcConstraints': ComponentMap(<transformed constraint>:
-                                       <src constraint>),
-        'transformedConstraints':
-            ComponentMap(<src constraint container> :
-                         <transformed constraint container>,
-                         <src constraintData> : [<transformed constraintDatas>])
-
-    All transformed Disjuncts will have a pointer to the block their transformed
-    constraints are on, and all transformed Disjunctions will have a
-    pointer to the corresponding OR or XOR constraint.
-
-    The _pyomo_gdp_hull_reformulation block will have a ComponentMap
-    "_disaggregationConstraintMap":
-        <src var>:ComponentMap(<srcDisjunction>: <disaggregation constraint>)
-
+    name beginning "_pyomo_gdp_hull_reformulation". It will contain an
+    indexed Block named "relaxedDisjuncts" that will hold the relaxed
+    disjuncts. This block is indexed by an integer indicating the order
+    in which the disjuncts were relaxed. All transformed Disjuncts will
+    have a pointer to the block their transformed constraints are on,
+    and all transformed Disjunctions will have a pointer to the
+    corresponding OR or XOR constraint.
     """
 
     CONFIG = cfg.ConfigDict('gdp.hull')
@@ -204,33 +205,40 @@ def __init__(self):
         super().__init__(logger)
         self._targets = set()
 
-    def _add_local_vars(self, block, local_var_dict):
+    def _collect_local_vars_from_block(self, block, local_var_dict):
         localVars = block.component('LocalVars')
-        if type(localVars) is Suffix:
+        if localVars is not None and localVars.ctype is Suffix:
             for disj, var_list in localVars.items():
-                if local_var_dict.get(disj) is None:
-                    local_var_dict[disj] = ComponentSet(var_list)
-                else:
-                    local_var_dict[disj].update(var_list)
-
-    def _get_local_var_suffixes(self, block, local_var_dict):
-        # You can specify suffixes on any block (disjuncts included). This
-        # method starts from a Disjunct (presumably) and checks for a LocalVar
-        # suffixes going both up and down the tree, adding them into the
-        # dictionary that is the second argument.
-
-        # first look beneath where we are (there could be Blocks on this
-        # disjunct)
-        for b in block.component_data_objects(
-            Block, descend_into=(Block), active=True, sort=SortComponents.deterministic
-        ):
-            self._add_local_vars(b, local_var_dict)
-        # now traverse upwards and get what's above
-        while block is not None:
-            self._add_local_vars(block, local_var_dict)
-            block = block.parent_block()
-
-        return local_var_dict
+                local_var_dict[disj].update(var_list)
+
+    def _get_user_defined_local_vars(self, targets):
+        user_defined_local_vars = defaultdict(ComponentSet)
+        seen_blocks = set()
+        # we go through the targets looking both up and down the hierarchy, but
+        # we cache what Blocks/Disjuncts we've already looked on so that we
+        # don't duplicate effort.
+        for t in targets:
+            if t.ctype is Disjunct:
+                # first look beneath where we are (there could be Blocks on this
+                # disjunct)
+                for b in t.component_data_objects(
+                    Block,
+                    descend_into=Block,
+                    active=True,
+                    sort=SortComponents.deterministic,
+                ):
+                    if b not in seen_blocks:
+                        self._collect_local_vars_from_block(b, user_defined_local_vars)
+                        seen_blocks.add(b)
+                # now look up in the tree
+                blk = t
+                while blk is not None:
+                    if blk in seen_blocks:
+                        break
+                    self._collect_local_vars_from_block(blk, user_defined_local_vars)
+                    seen_blocks.add(blk)
+                    blk = blk.parent_block()
+        return user_defined_local_vars
 
     def _apply_to(self, instance, **kwds):
         try:
@@ -239,7 +247,6 @@ def _apply_to(self, instance, **kwds):
             self._restore_state()
             self._transformation_blocks.clear()
             self._algebraic_constraints.clear()
-            self._targets_set = set()
 
     def _apply_to_impl(self, instance, **kwds):
         self._process_arguments(instance, **kwds)
@@ -253,16 +260,17 @@ def _apply_to_impl(self, instance, **kwds):
         # Preprocess in order to find what disjunctive components need
         # transformation
         gdp_tree = self._get_gdp_tree_from_targets(instance, targets)
-        preprocessed_targets = gdp_tree.topological_sort()
-        self._targets_set = set(preprocessed_targets)
+        # Transform from leaf to root: This is important for hull because for
+        # nested GDPs, we will introduce variables that need disaggregating into
+        # parent Disjuncts as we transform their child Disjunctions.
+        preprocessed_targets = gdp_tree.reverse_topological_sort()
+        # Get all LocalVars from Suffixes ahead of time
+        local_vars_by_disjunct = self._get_user_defined_local_vars(preprocessed_targets)
 
         for t in preprocessed_targets:
             if t.ctype is Disjunction:
                 self._transform_disjunctionData(
-                    t,
-                    t.index(),
-                    parent_disjunct=gdp_tree.parent(t),
-                    root_disjunct=gdp_tree.root_disjunct(t),
+                    t, t.index(), gdp_tree.parent(t), local_vars_by_disjunct
                 )
             # We skip disjuncts now, because we need information from the
             # disjunctions to transform them (which variables to disaggregate),
@@ -274,23 +282,11 @@ def _add_transformation_block(self, to_block):
             return transBlock, new_block
 
         transBlock.lbub = Set(initialize=['lb', 'ub', 'eq'])
-        # Map between disaggregated variables and their
-        # originals
-        transBlock._disaggregatedVarMap = {
-            'srcVar': ComponentMap(),
-            'disaggregatedVar': ComponentMap(),
-        }
-        # Map between disaggregated variables and their lb*indicator <= var <=
-        # ub*indicator constraints
-        transBlock._bigMConstraintMap = ComponentMap()
+
         # We will store all of the disaggregation constraints for any
         # Disjunctions we transform onto this block here.
         transBlock.disaggregationConstraints = Constraint(NonNegativeIntegers)
 
-        # This will map from srcVar to a map of srcDisjunction to the
-        # disaggregation constraint corresponding to srcDisjunction
-        transBlock._disaggregationConstraintMap = ComponentMap()
-
         # we are going to store some of the disaggregated vars directly here
         # when we have vars that don't appear in every disjunct
         transBlock._disaggregatedVars = Var(NonNegativeIntegers, dense=False)
@@ -299,46 +295,55 @@ def _add_transformation_block(self, to_block):
         return transBlock, True
 
     def _transform_disjunctionData(
-        self, obj, index, parent_disjunct=None, root_disjunct=None
+        self, obj, index, parent_disjunct, local_vars_by_disjunct
     ):
         # Hull reformulation doesn't work if this is an OR constraint. So if
         # xor is false, give up
         if not obj.xor:
             raise GDP_Error(
                 "Cannot do hull reformulation for "
-                "Disjunction '%s' with OR constraint.  "
+                "Disjunction '%s' with OR constraint. "
                 "Must be an XOR!" % obj.name
             )
-
+        # collect the Disjuncts we are going to transform now because we will
+        # change their active status when we transform them, but we still need
+        # this list after the fact.
+        active_disjuncts = [disj for disj in obj.disjuncts if disj.active]
+
+        # We put *all* transformed things on the parent Block of this
+        # disjunction. We'll mark the disaggregated Vars as local, but beyond
+        # that, we actually need everything to get transformed again as we go up
+        # the nested hierarchy (if there is one)
         transBlock, xorConstraint = self._setup_transform_disjunctionData(
-            obj, root_disjunct
+            obj, root_disjunct=None
         )
 
         disaggregationConstraint = transBlock.disaggregationConstraints
-        disaggregationConstraintMap = transBlock._disaggregationConstraintMap
+        disaggregationConstraintMap = (
+            transBlock.private_data().disaggregation_constraint_map
+        )
         disaggregatedVars = transBlock._disaggregatedVars
         disaggregated_var_bounds = transBlock._boundsConstraints
 
-        # We first go through and collect all the variables that we
-        # are going to disaggregate.
-        varOrder_set = ComponentSet()
-        varOrder = []
-        varsByDisjunct = ComponentMap()
-        localVarsByDisjunct = ComponentMap()
-        include_fixed_vars = not self._config.assume_fixed_vars_permanent
-        for disjunct in obj.disjuncts:
-            if not disjunct.active:
-                continue
-            disjunctVars = varsByDisjunct[disjunct] = ComponentSet()
+        # We first go through and collect all the variables that we are going to
+        # disaggregate. We do this in its own pass because we want to know all
+        # the Disjuncts that each Var appears in since that will tell us exactly
+        # which diaggregated variables we need.
+        var_order = ComponentSet()
+        disjuncts_var_appears_in = ComponentMap()
+        # For each disjunct in the disjunction, we will store a list of Vars
+        # that need a disaggregated counterpart in that disjunct.
+        disjunct_disaggregated_var_map = {}
+        for disjunct in active_disjuncts:
             # create the key for each disjunct now
-            transBlock._disaggregatedVarMap['disaggregatedVar'][
-                disjunct
-            ] = ComponentMap()
-            for cons in disjunct.component_data_objects(
+            disjunct_disaggregated_var_map[disjunct] = ComponentMap()
+            for var in get_vars_from_components(
+                disjunct,
                 Constraint,
+                include_fixed=not self._config.assume_fixed_vars_permanent,
                 active=True,
                 sort=SortComponents.deterministic,
-                descend_into=(Block, Disjunct),
+                descend_into=Block,
             ):
                 # [ESJ 02/14/2020] By default, we disaggregate fixed variables
                 # on the philosophy that fixing is not a promise for the future
@@ -347,189 +352,159 @@ def _transform_disjunctionData(
                 # with their transformed model. However, the user may have set
                 # assume_fixed_vars_permanent to True in which case we will skip
                 # them
-                for var in EXPR.identify_variables(
-                    cons.body, include_fixed=include_fixed_vars
-                ):
-                    # Note the use of a list so that we will
-                    # eventually disaggregate the vars in a
-                    # deterministic order (the order that we found
-                    # them)
-                    disjunctVars.add(var)
-                    if not var in varOrder_set:
-                        varOrder.append(var)
-                        varOrder_set.add(var)
-
-            # check for LocalVars Suffix
-            localVarsByDisjunct = self._get_local_var_suffixes(
-                disjunct, localVarsByDisjunct
-            )
 
-        # We will disaggregate all variables that are not explicitly declared as
-        # being local. Since we transform from leaf to root, we are implicitly
-        # treating our own disaggregated variables as local, so they will not be
+                # Note that, because ComponentSets are ordered, we will
+                # eventually disaggregate the vars in a deterministic order
+                # (the order that we found them)
+                if var not in var_order:
+                    var_order.add(var)
+                    disjuncts_var_appears_in[var] = ComponentSet([disjunct])
+                else:
+                    disjuncts_var_appears_in[var].add(disjunct)
+
+        # Now, we will disaggregate all variables that are not explicitly
+        # declared as being local. If we are moving up in a nested tree, we have
+        # marked our own disaggregated variables as local, so they will not be
         # re-disaggregated.
-        varSet = []
-        varSet = {disj: [] for disj in obj.disjuncts}
-        # Note that variables are local with respect to a Disjunct. We deal with
-        # them here to do some error checking (if something is obviously not
-        # local since it is used in multiple Disjuncts in this Disjunction) and
-        # also to get a deterministic order in which to process them when we
-        # transform the Disjuncts: Values of localVarsByDisjunct are
-        # ComponentSets, so we need this for determinism (we iterate through the
-        # localVars of a Disjunct later)
-        localVars = ComponentMap()
-        varsToDisaggregate = []
-        disjunctsVarAppearsIn = ComponentMap()
-        for var in varOrder:
-            disjuncts = disjunctsVarAppearsIn[var] = [
-                d for d in varsByDisjunct if var in varsByDisjunct[d]
-            ]
+        vars_to_disaggregate = {disj: ComponentSet() for disj in obj.disjuncts}
+        all_vars_to_disaggregate = ComponentSet()
+        # We will ignore variables declared as local in a Disjunct that don't
+        # actually appear in any Constraints on that Disjunct, but in order to
+        # do this, we will explicitly collect the set of local_vars in this
+        # loop.
+        local_vars = defaultdict(ComponentSet)
+        for var in var_order:
+            disjuncts = disjuncts_var_appears_in[var]
             # clearly not local if used in more than one disjunct
             if len(disjuncts) > 1:
                 if self._generate_debug_messages:
                     logger.debug(
                         "Assuming '%s' is not a local var since it is"
-                        "used in multiple disjuncts."
-                        % var.getname(fully_qualified=True)
+                        "used in multiple disjuncts." % var.name
                     )
                 for disj in disjuncts:
-                    varSet[disj].append(var)
-                varsToDisaggregate.append(var)
-            # disjuncts is a list of length 1
-            elif localVarsByDisjunct.get(disjuncts[0]) is not None:
-                if var in localVarsByDisjunct[disjuncts[0]]:
-                    localVars_thisDisjunct = localVars.get(disjuncts[0])
-                    if localVars_thisDisjunct is not None:
-                        localVars[disjuncts[0]].append(var)
-                    else:
-                        localVars[disjuncts[0]] = [var]
-                else:
-                    # It's not local to this Disjunct
-                    varSet[disjuncts[0]].append(var)
-                    varsToDisaggregate.append(var)
-            else:
-                # We don't even have have any local vars for this Disjunct.
-                varSet[disjuncts[0]].append(var)
-                varsToDisaggregate.append(var)
+                    vars_to_disaggregate[disj].add(var)
+                    all_vars_to_disaggregate.add(var)
+            else:  # var only appears in one disjunct
+                disjunct = next(iter(disjuncts))
+                # We check if the user declared it as local
+                if disjunct in local_vars_by_disjunct:
+                    if var in local_vars_by_disjunct[disjunct]:
+                        local_vars[disjunct].add(var)
+                        continue
+                # It's not declared local to this Disjunct, so we
+                # disaggregate
+                vars_to_disaggregate[disjunct].add(var)
+                all_vars_to_disaggregate.add(var)
 
         # Now that we know who we need to disaggregate, we will do it
         # while we also transform the disjuncts.
-        local_var_set = self._get_local_var_set(obj)
+
+        # Get the list of local variables for the parent Disjunct so that we can
+        # add the disaggregated variables we're about to make to it:
+        parent_local_var_list = self._get_local_var_list(parent_disjunct)
         or_expr = 0
         for disjunct in obj.disjuncts:
             or_expr += disjunct.indicator_var.get_associated_binary()
-            self._transform_disjunct(
-                disjunct,
-                transBlock,
-                varSet[disjunct],
-                localVars.get(disjunct, []),
-                local_var_set,
-            )
-        rhs = 1 if parent_disjunct is None else parent_disjunct.binary_indicator_var
-        xorConstraint.add(index, (or_expr, rhs))
+            if disjunct.active:
+                self._transform_disjunct(
+                    obj=disjunct,
+                    transBlock=transBlock,
+                    vars_to_disaggregate=vars_to_disaggregate[disjunct],
+                    local_vars=local_vars[disjunct],
+                    parent_local_var_suffix=parent_local_var_list,
+                    parent_disjunct_local_vars=local_vars_by_disjunct[parent_disjunct],
+                    disjunct_disaggregated_var_map=disjunct_disaggregated_var_map,
+                )
+        xorConstraint.add(index, (or_expr, 1))
         # map the DisjunctionData to its XOR constraint to mark it as
         # transformed
         obj._algebraic_constraint = weakref_ref(xorConstraint[index])
 
-        # add the reaggregation constraints
-        for i, var in enumerate(varsToDisaggregate):
+        # Now add the reaggregation constraints
+        for var in all_vars_to_disaggregate:
             # There are two cases here: Either the var appeared in every
             # disjunct in the disjunction, or it didn't. If it did, there's
             # nothing special to do: All of the disaggregated variables have
             # been created, and we can just proceed and make this constraint. If
             # it didn't, we need one more disaggregated variable, correctly
             # defined. And then we can make the constraint.
-            if len(disjunctsVarAppearsIn[var]) < len(obj.disjuncts):
+            if len(disjuncts_var_appears_in[var]) < len(active_disjuncts):
                 # create one more disaggregated var
                 idx = len(disaggregatedVars)
                 disaggregated_var = disaggregatedVars[idx]
-                # mark this as local because we won't re-disaggregate if this is
-                # a nested disjunction
-                if local_var_set is not None:
-                    local_var_set.append(disaggregated_var)
+                # mark this as local because we won't re-disaggregate it if this
+                # is a nested disjunction
+                if parent_local_var_list is not None:
+                    parent_local_var_list.append(disaggregated_var)
+                local_vars_by_disjunct[parent_disjunct].add(disaggregated_var)
                 var_free = 1 - sum(
                     disj.indicator_var.get_associated_binary()
-                    for disj in disjunctsVarAppearsIn[var]
+                    for disj in disjuncts_var_appears_in[var]
                 )
                 self._declare_disaggregated_var_bounds(
-                    var,
-                    disaggregated_var,
-                    obj,
-                    disaggregated_var_bounds,
-                    (idx, 'lb'),
-                    (idx, 'ub'),
-                    var_free,
+                    original_var=var,
+                    disaggregatedVar=disaggregated_var,
+                    disjunct=obj,
+                    bigmConstraint=disaggregated_var_bounds,
+                    lb_idx=(idx, 'lb'),
+                    ub_idx=(idx, 'ub'),
+                    var_free_indicator=var_free,
+                )
+                # Update mappings:
+                var_info = var.parent_block().private_data()
+                disaggregated_var_map = var_info.disaggregated_var_map
+                dis_var_info = disaggregated_var.parent_block().private_data()
+
+                dis_var_info.bigm_constraint_map[disaggregated_var][obj] = Reference(
+                    disaggregated_var_bounds[idx, :]
                 )
-                # maintain the mappings
-                for disj in obj.disjuncts:
+                dis_var_info.original_var_map[disaggregated_var] = var
+
+                # For every Disjunct the Var does not appear in, we want to map
+                # that this new variable is its disaggreggated variable.
+                for disj in active_disjuncts:
                     # Because we called _transform_disjunct above, we know that
                     # if this isn't transformed it is because it was cleanly
                     # deactivated, and we can just skip it.
                     if (
                         disj._transformation_block is not None
-                        and disj not in disjunctsVarAppearsIn[var]
+                        and disj not in disjuncts_var_appears_in[var]
                     ):
-                        relaxationBlock = disj._transformation_block().parent_block()
-                        relaxationBlock._bigMConstraintMap[disaggregated_var] = (
-                            Reference(disaggregated_var_bounds[idx, :])
-                        )
-                        relaxationBlock._disaggregatedVarMap['srcVar'][
-                            disaggregated_var
-                        ] = var
-                        relaxationBlock._disaggregatedVarMap['disaggregatedVar'][disj][
-                            var
-                        ] = disaggregated_var
+                        disaggregated_var_map[disj][var] = disaggregated_var
 
+                # start the expression for the reaggregation constraint with
+                # this var
                 disaggregatedExpr = disaggregated_var
             else:
                 disaggregatedExpr = 0
-            for disjunct in disjunctsVarAppearsIn[var]:
-                if disjunct._transformation_block is None:
-                    # Because we called _transform_disjunct above, we know that
-                    # if this isn't transformed it is because it was cleanly
-                    # deactivated, and we can just skip it.
-                    continue
+            for disjunct in disjuncts_var_appears_in[var]:
+                disaggregatedExpr += disjunct_disaggregated_var_map[disjunct][var]
 
-                disaggregatedVar = (
-                    disjunct._transformation_block()
-                    .parent_block()
-                    ._disaggregatedVarMap['disaggregatedVar'][disjunct][var]
-                )
-                disaggregatedExpr += disaggregatedVar
-
-            # We equate the sum of the disaggregated vars to var (the original)
-            # if parent_disjunct is None, else it needs to be the disaggregated
-            # var corresponding to var on the parent disjunct. This is the
-            # reason we transform from root to leaf: This constraint is now
-            # correct regardless of how nested something may have been.
-            parent_var = (
-                var
-                if parent_disjunct is None
-                else self.get_disaggregated_var(var, parent_disjunct)
-            )
             cons_idx = len(disaggregationConstraint)
-            disaggregationConstraint.add(cons_idx, parent_var == disaggregatedExpr)
+            # We always aggregate to the original var. If this is nested, this
+            # constraint will be transformed again. (And if it turns out
+            # everything in it is local, then that transformation won't actually
+            # change the mathematical expression, so it's okay.
+            disaggregationConstraint.add(cons_idx, var == disaggregatedExpr)
             # and update the map so that we can find this later. We index by
             # variable and the particular disjunction because there is a
             # different one for each disjunction
-            if disaggregationConstraintMap.get(var) is not None:
-                disaggregationConstraintMap[var][obj] = disaggregationConstraint[
-                    cons_idx
-                ]
-            else:
-                thismap = disaggregationConstraintMap[var] = ComponentMap()
-                thismap[obj] = disaggregationConstraint[cons_idx]
+            disaggregationConstraintMap[var][obj] = disaggregationConstraint[cons_idx]
 
         # deactivate for the writers
         obj.deactivate()
 
-    def _transform_disjunct(self, obj, transBlock, varSet, localVars, local_var_set):
-        # We're not using the preprocessed list here, so this could be
-        # inactive. We've already done the error checking in preprocessing, so
-        # we just skip it here.
-        if not obj.active:
-            return
-
+    def _transform_disjunct(
+        self,
+        obj,
+        transBlock,
+        vars_to_disaggregate,
+        local_vars,
+        parent_local_var_suffix,
+        parent_disjunct_local_vars,
+        disjunct_disaggregated_var_map,
+    ):
         relaxationBlock = self._get_disjunct_transformation_block(obj, transBlock)
 
         # Put the disaggregated variables all on their own block so that we can
@@ -539,7 +514,7 @@ def _transform_disjunct(self, obj, transBlock, varSet, localVars, local_var_set)
 
         # add the disaggregated variables and their bigm constraints
         # to the relaxationBlock
-        for var in varSet:
+        for var in vars_to_disaggregate:
             disaggregatedVar = Var(within=Reals, initialize=var.value)
             # naming conflicts are possible here since this is a bunch
             # of variables from different blocks coming together, so we
@@ -550,10 +525,13 @@ def _transform_disjunct(self, obj, transBlock, varSet, localVars, local_var_set)
             relaxationBlock.disaggregatedVars.add_component(
                 disaggregatedVarName, disaggregatedVar
             )
-            # mark this as local because we won't re-disaggregate if this is a
-            # nested disjunction
-            if local_var_set is not None:
-                local_var_set.append(disaggregatedVar)
+            # mark this as local via the Suffix in case this is a partial
+            # transformation:
+            if parent_local_var_suffix is not None:
+                parent_local_var_suffix.append(disaggregatedVar)
+            # Record that it's local for our own bookkeeping in case we're in a
+            # nested tree in *this* transformation
+            parent_disjunct_local_vars.add(disaggregatedVar)
 
             # add the bigm constraint
             bigmConstraint = Constraint(transBlock.lbub)
@@ -562,19 +540,22 @@ def _transform_disjunct(self, obj, transBlock, varSet, localVars, local_var_set)
             )
 
             self._declare_disaggregated_var_bounds(
-                var,
-                disaggregatedVar,
-                obj,
-                bigmConstraint,
-                'lb',
-                'ub',
-                obj.indicator_var.get_associated_binary(),
-                transBlock,
+                original_var=var,
+                disaggregatedVar=disaggregatedVar,
+                disjunct=obj,
+                bigmConstraint=bigmConstraint,
+                lb_idx='lb',
+                ub_idx='ub',
+                var_free_indicator=obj.indicator_var.get_associated_binary(),
             )
+            # update the bigm constraint mappings
+            data_dict = disaggregatedVar.parent_block().private_data()
+            data_dict.bigm_constraint_map[disaggregatedVar][obj] = bigmConstraint
+            disjunct_disaggregated_var_map[obj][var] = disaggregatedVar
 
-        for var in localVars:
-            # we don't need to disaggregated, we can use this Var, but we do
-            # need to set up its bounds constraints.
+        for var in local_vars:
+            # we don't need to disaggregate, i.e., we can use this Var, but we
+            # do need to set up its bounds constraints.
 
             # naming conflicts are possible here since this is a bunch
             # of variables from different blocks coming together, so we
@@ -585,36 +566,38 @@ def _transform_disjunct(self, obj, transBlock, varSet, localVars, local_var_set)
             bigmConstraint = Constraint(transBlock.lbub)
             relaxationBlock.add_component(conName, bigmConstraint)
 
+            parent_block = var.parent_block()
+
             self._declare_disaggregated_var_bounds(
-                var,
-                var,
-                obj,
-                bigmConstraint,
-                'lb',
-                'ub',
-                obj.indicator_var.get_associated_binary(),
-                transBlock,
+                original_var=var,
+                disaggregatedVar=var,
+                disjunct=obj,
+                bigmConstraint=bigmConstraint,
+                lb_idx='lb',
+                ub_idx='ub',
+                var_free_indicator=obj.indicator_var.get_associated_binary(),
             )
+            # update the bigm constraint mappings
+            data_dict = var.parent_block().private_data()
+            data_dict.bigm_constraint_map[var][obj] = bigmConstraint
+            disjunct_disaggregated_var_map[obj][var] = var
 
         var_substitute_map = dict(
-            (id(v), newV)
-            for v, newV in transBlock._disaggregatedVarMap['disaggregatedVar'][
-                obj
-            ].items()
+            (id(v), newV) for v, newV in disjunct_disaggregated_var_map[obj].items()
         )
         zero_substitute_map = dict(
             (id(v), ZeroConstant)
-            for v, newV in transBlock._disaggregatedVarMap['disaggregatedVar'][
-                obj
-            ].items()
+            for v, newV in disjunct_disaggregated_var_map[obj].items()
         )
-        zero_substitute_map.update((id(v), ZeroConstant) for v in localVars)
 
         # Transform each component within this disjunct
         self._transform_block_components(
             obj, obj, var_substitute_map, zero_substitute_map
         )
 
+        # Anything that was local to this Disjunct is also local to the parent,
+        # and just got "promoted" up there, so to speak.
+        parent_disjunct_local_vars.update(local_vars)
         # deactivate disjunct so writers can be happy
         obj._deactivate_without_fixing_indicator()
 
@@ -627,10 +610,7 @@ def _declare_disaggregated_var_bounds(
         lb_idx,
         ub_idx,
         var_free_indicator,
-        transBlock=None,
     ):
-        # If transBlock is None then this is a disaggregated variable for
-        # multiple Disjuncts and we will handle the mappings separately.
         lb = original_var.lb
         ub = original_var.ub
         if lb is None or ub is None:
@@ -648,61 +628,39 @@ def _declare_disaggregated_var_bounds(
         if ub:
             bigmConstraint.add(ub_idx, disaggregatedVar <= ub * var_free_indicator)
 
+        original_var_info = original_var.parent_block().private_data()
+        disaggregated_var_map = original_var_info.disaggregated_var_map
+        disaggregated_var_info = disaggregatedVar.parent_block().private_data()
+
         # store the mappings from variables to their disaggregated selves on
-        # the transformation block.
-        if transBlock is not None:
-            transBlock._disaggregatedVarMap['disaggregatedVar'][disjunct][
-                original_var
-            ] = disaggregatedVar
-            transBlock._disaggregatedVarMap['srcVar'][disaggregatedVar] = original_var
-            transBlock._bigMConstraintMap[disaggregatedVar] = bigmConstraint
-
-    def _get_local_var_set(self, disjunction):
-        # add Suffix to the relaxation block that disaggregated variables are
-        # local (in case this is nested in another Disjunct)
-        local_var_set = None
-        parent_disjunct = disjunction.parent_block()
-        while parent_disjunct is not None:
-            if parent_disjunct.ctype is Disjunct:
-                break
-            parent_disjunct = parent_disjunct.parent_block()
+        # the transformation block
+        disaggregated_var_map[disjunct][original_var] = disaggregatedVar
+        disaggregated_var_info.original_var_map[disaggregatedVar] = original_var
+
+    def _get_local_var_list(self, parent_disjunct):
+        # Add or retrieve Suffix from parent_disjunct so that, if this is
+        # nested, we can use it to declare that the disaggregated variables are
+        # local. We return the list so that we can add to it.
+        local_var_list = None
         if parent_disjunct is not None:
             # This limits the cases that a user is allowed to name something
             # (other than a Suffix) 'LocalVars' on a Disjunct. But I am assuming
             # that the Suffix has to be somewhere above the disjunct in the
             # tree, so I can't put it on a Block that I own. And if I'm coopting
             # something of theirs, it may as well be here.
-            self._add_local_var_suffix(parent_disjunct)
+            self._get_local_var_suffix(parent_disjunct)
             if parent_disjunct.LocalVars.get(parent_disjunct) is None:
                 parent_disjunct.LocalVars[parent_disjunct] = []
-            local_var_set = parent_disjunct.LocalVars[parent_disjunct]
+            local_var_list = parent_disjunct.LocalVars[parent_disjunct]
 
-        return local_var_set
-
-    def _warn_for_active_disjunct(
-        self, innerdisjunct, outerdisjunct, var_substitute_map, zero_substitute_map
-    ):
-        # We override the base class method because in hull, it might just be
-        # that we haven't gotten here yet.
-        disjuncts = (
-            innerdisjunct.values() if innerdisjunct.is_indexed() else (innerdisjunct,)
-        )
-        for disj in disjuncts:
-            if disj in self._targets_set:
-                # We're getting to this, have some patience.
-                continue
-            else:
-                # But if it wasn't in the targets after preprocessing, it
-                # doesn't belong in an active Disjunction that we are
-                # transforming and we should be confused.
-                _warn_for_active_disjunct(innerdisjunct, outerdisjunct)
+        return local_var_list
 
     def _transform_constraint(
         self, obj, disjunct, var_substitute_map, zero_substitute_map
     ):
         # we will put a new transformed constraint on the relaxation block.
         relaxationBlock = disjunct._transformation_block()
-        constraintMap = relaxationBlock._constraintMap
+        constraint_map = relaxationBlock.private_data('pyomo.gdp')
 
         # We will make indexes from ({obj.local_name} x obj.index_set() x ['lb',
         # 'ub']), but don't bother construct that set here, as taking Cartesian
@@ -784,32 +742,32 @@ def _transform_constraint(
                         # this variable, so I'm going to return
                         # it. Alternatively we could return an empty list, but I
                         # think I like this better.
-                        constraintMap['transformedConstraints'][c] = [v[0]]
+                        constraint_map.transformed_constraints[c].append(v[0])
                         # Reverse map also (this is strange)
-                        constraintMap['srcConstraints'][v[0]] = c
+                        constraint_map.src_constraint[v[0]] = c
                         continue
                     newConsExpr = expr - (1 - y) * h_0 == c.lower * y
 
                 if obj.is_indexed():
                     newConstraint.add((name, i, 'eq'), newConsExpr)
-                    # map the _ConstraintDatas (we mapped the container above)
-                    constraintMap['transformedConstraints'][c] = [
+                    # map the ConstraintDatas (we mapped the container above)
+                    constraint_map.transformed_constraints[c].append(
                         newConstraint[name, i, 'eq']
-                    ]
-                    constraintMap['srcConstraints'][newConstraint[name, i, 'eq']] = c
+                    )
+                    constraint_map.src_constraint[newConstraint[name, i, 'eq']] = c
                 else:
                     newConstraint.add((name, 'eq'), newConsExpr)
-                    # map to the _ConstraintData (And yes, for
+                    # map to the ConstraintData (And yes, for
                     # ScalarConstraints, this is overwriting the map to the
                     # container we made above, and that is what I want to
                     # happen. ScalarConstraints will map to lists. For
                     # IndexedConstraints, we can map the container to the
                     # container, but more importantly, we are mapping the
-                    # _ConstraintDatas to each other above)
-                    constraintMap['transformedConstraints'][c] = [
+                    # ConstraintDatas to each other above)
+                    constraint_map.transformed_constraints[c].append(
                         newConstraint[name, 'eq']
-                    ]
-                    constraintMap['srcConstraints'][newConstraint[name, 'eq']] = c
+                    )
+                    constraint_map.src_constraint[newConstraint[name, 'eq']] = c
 
                 continue
 
@@ -824,16 +782,16 @@ def _transform_constraint(
 
                 if obj.is_indexed():
                     newConstraint.add((name, i, 'lb'), newConsExpr)
-                    constraintMap['transformedConstraints'][c] = [
+                    constraint_map.transformed_constraints[c].append(
                         newConstraint[name, i, 'lb']
-                    ]
-                    constraintMap['srcConstraints'][newConstraint[name, i, 'lb']] = c
+                    )
+                    constraint_map.src_constraint[newConstraint[name, i, 'lb']] = c
                 else:
                     newConstraint.add((name, 'lb'), newConsExpr)
-                    constraintMap['transformedConstraints'][c] = [
+                    constraint_map.transformed_constraints[c].append(
                         newConstraint[name, 'lb']
-                    ]
-                    constraintMap['srcConstraints'][newConstraint[name, 'lb']] = c
+                    )
+                    constraint_map.src_constraint[newConstraint[name, 'lb']] = c
 
             if c.upper is not None:
                 if self._generate_debug_messages:
@@ -848,29 +806,21 @@ def _transform_constraint(
                     newConstraint.add((name, i, 'ub'), newConsExpr)
                     # map (have to account for fact we might have created list
                     # above
-                    transformed = constraintMap['transformedConstraints'].get(c)
-                    if transformed is not None:
-                        transformed.append(newConstraint[name, i, 'ub'])
-                    else:
-                        constraintMap['transformedConstraints'][c] = [
-                            newConstraint[name, i, 'ub']
-                        ]
-                    constraintMap['srcConstraints'][newConstraint[name, i, 'ub']] = c
+                    constraint_map.transformed_constraints[c].append(
+                        newConstraint[name, i, 'ub']
+                    )
+                    constraint_map.src_constraint[newConstraint[name, i, 'ub']] = c
                 else:
                     newConstraint.add((name, 'ub'), newConsExpr)
-                    transformed = constraintMap['transformedConstraints'].get(c)
-                    if transformed is not None:
-                        transformed.append(newConstraint[name, 'ub'])
-                    else:
-                        constraintMap['transformedConstraints'][c] = [
-                            newConstraint[name, 'ub']
-                        ]
-                    constraintMap['srcConstraints'][newConstraint[name, 'ub']] = c
+                    constraint_map.transformed_constraints[c].append(
+                        newConstraint[name, 'ub']
+                    )
+                    constraint_map.src_constraint[newConstraint[name, 'ub']] = c
 
         # deactivate now that we have transformed
         obj.deactivate()
 
-    def _add_local_var_suffix(self, disjunct):
+    def _get_local_var_suffix(self, disjunct):
         # If the Suffix is there, we will borrow it. If not, we make it. If it's
         # something else, we complain.
         localSuffix = disjunct.component("LocalVars")
@@ -885,7 +835,7 @@ def _add_local_var_suffix(self, disjunct):
                 % (disjunct.getname(fully_qualified=True), localSuffix.ctype)
             )
 
-    def get_disaggregated_var(self, v, disjunct):
+    def get_disaggregated_var(self, v, disjunct, raise_exception=True):
         """
         Returns the disaggregated variable corresponding to the Var v and the
         Disjunct disjunct.
@@ -899,15 +849,16 @@ def get_disaggregated_var(self, v, disjunct):
         """
         if disjunct._transformation_block is None:
             raise GDP_Error("Disjunct '%s' has not been transformed" % disjunct.name)
-        transBlock = disjunct._transformation_block().parent_block()
-        try:
-            return transBlock._disaggregatedVarMap['disaggregatedVar'][disjunct][v]
-        except:
-            logger.error(
-                "It does not appear '%s' is a "
-                "variable that appears in disjunct '%s'" % (v.name, disjunct.name)
-            )
-            raise
+        msg = (
+            "It does not appear '%s' is a "
+            "variable that appears in disjunct '%s'" % (v.name, disjunct.name)
+        )
+        disaggregated_var_map = v.parent_block().private_data().disaggregated_var_map
+        if v in disaggregated_var_map[disjunct]:
+            return disaggregated_var_map[disjunct][v]
+        else:
+            if raise_exception:
+                raise GDP_Error(msg)
 
     def get_src_var(self, disaggregated_var):
         """
@@ -916,35 +867,24 @@ def get_src_var(self, disaggregated_var):
 
         Parameters
         ----------
-        disaggregated_var: a Var which was created by the hull
+        disaggregated_var: a Var that was created by the hull
                            transformation as a disaggregated variable
                            (and so appears on a transformation block
                            of some Disjunct)
         """
-        msg = (
+        var_map = disaggregated_var.parent_block().private_data()
+        if disaggregated_var in var_map.original_var_map:
+            return var_map.original_var_map[disaggregated_var]
+        raise GDP_Error(
             "'%s' does not appear to be a "
             "disaggregated variable" % disaggregated_var.name
         )
-        # There are two possibilities: It is declared on a Disjunct
-        # transformation Block, or it is declared on the parent of a Disjunct
-        # transformation block (if it is a single variable for multiple
-        # Disjuncts the original doesn't appear in)
-        transBlock = disaggregated_var.parent_block()
-        if not hasattr(transBlock, '_disaggregatedVarMap'):
-            try:
-                transBlock = transBlock.parent_block().parent_block()
-            except:
-                logger.error(msg)
-                raise
-        try:
-            return transBlock._disaggregatedVarMap['srcVar'][disaggregated_var]
-        except:
-            logger.error(msg)
-            raise
 
     # retrieves the disaggregation constraint for original_var resulting from
     # transforming disjunction
-    def get_disaggregation_constraint(self, original_var, disjunction):
+    def get_disaggregation_constraint(
+        self, original_var, disjunction, raise_exception=True
+    ):
         """
         Returns the disaggregation (re-aggregation?) constraint
         (which links the disaggregated variables to their original)
@@ -957,7 +897,7 @@ def get_disaggregation_constraint(self, original_var, disjunction):
         disjunction: a transformed Disjunction containing original_var
         """
         for disjunct in disjunction.disjuncts:
-            transBlock = disjunct._transformation_block
+            transBlock = disjunct.transformation_block
             if transBlock is not None:
                 break
         if transBlock is None:
@@ -968,20 +908,25 @@ def get_disaggregation_constraint(self, original_var, disjunction):
             )
 
         try:
-            return (
-                transBlock()
-                .parent_block()
-                ._disaggregationConstraintMap[original_var][disjunction]
+            cons = (
+                transBlock.parent_block()
+                .private_data()
+                .disaggregation_constraint_map[original_var][disjunction]
             )
         except:
-            logger.error(
-                "It doesn't appear that '%s' is a variable that was "
-                "disaggregated by Disjunction '%s'"
-                % (original_var.name, disjunction.name)
-            )
-            raise
+            if raise_exception:
+                logger.error(
+                    "It doesn't appear that '%s' is a variable that was "
+                    "disaggregated by Disjunction '%s'"
+                    % (original_var.name, disjunction.name)
+                )
+                raise
+            return None
+        while not cons.active:
+            cons = self.get_transformed_constraints(cons)[0]
+        return cons
 
-    def get_var_bounds_constraint(self, v):
+    def get_var_bounds_constraint(self, v, disjunct=None):
         """
         Returns the IndexedConstraint which sets a disaggregated
         variable to be within its bounds when its Disjunct is active and to
@@ -990,28 +935,43 @@ def get_var_bounds_constraint(self, v):
 
         Parameters
         ----------
-        v: a Var which was created by the hull  transformation as a
+        v: a Var that was created by the hull transformation as a
            disaggregated variable (and so appears on a transformation
            block of some Disjunct)
+        disjunct: (For nested Disjunctions) Which Disjunct in the
+           hierarchy the bounds Constraint should correspond to.
+           Optional since for non-nested models this can be inferred.
         """
-        msg = (
+        info = v.parent_block().private_data()
+        if v in info.bigm_constraint_map:
+            if len(info.bigm_constraint_map[v]) == 1:
+                # Not nested, or it's at the top layer, so we're fine.
+                return list(info.bigm_constraint_map[v].values())[0]
+            elif disjunct is not None:
+                # This is nested, so we need to walk up to find the active ones
+                return info.bigm_constraint_map[v][disjunct]
+            else:
+                raise ValueError(
+                    "It appears that the variable '%s' appears "
+                    "within a nested GDP hierarchy, and no "
+                    "'disjunct' argument was specified. Please "
+                    "specify for which Disjunct the bounds "
+                    "constraint for '%s' should be returned." % (v, v)
+                )
+        raise GDP_Error(
             "Either '%s' is not a disaggregated variable, or "
             "the disjunction that disaggregates it has not "
             "been properly transformed." % v.name
         )
-        # This can only go well if v is a disaggregated var
-        transBlock = v.parent_block()
-        if not hasattr(transBlock, '_bigMConstraintMap'):
-            try:
-                transBlock = transBlock.parent_block().parent_block()
-            except:
-                logger.error(msg)
-                raise
-        try:
-            return transBlock._bigMConstraintMap[v]
-        except:
-            logger.error(msg)
-            raise
+
+    def get_transformed_constraints(self, cons):
+        cons = super().get_transformed_constraints(cons)
+        while not cons[0].active:
+            transformed_cons = []
+            for con in cons:
+                transformed_cons += super().get_transformed_constraints(con)
+            cons = transformed_cons
+        return cons
 
 
 @TransformationFactory.register(
diff --git a/pyomo/gdp/plugins/multiple_bigm.py b/pyomo/gdp/plugins/multiple_bigm.py
index 85fb1e4aa6b..3362276246b 100644
--- a/pyomo/gdp/plugins/multiple_bigm.py
+++ b/pyomo/gdp/plugins/multiple_bigm.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -12,7 +12,7 @@
 import itertools
 import logging
 
-from pyomo.common.collections import ComponentMap
+from pyomo.common.collections import ComponentMap, ComponentSet
 from pyomo.common.config import ConfigDict, ConfigValue
 from pyomo.common.gc_manager import PauseGC
 from pyomo.common.modeling import unique_component_name
@@ -31,7 +31,6 @@
     NonNegativeIntegers,
     Objective,
     Param,
-    RangeSet,
     Set,
     SetOf,
     SortComponents,
@@ -60,6 +59,18 @@
 
 logger = logging.getLogger('pyomo.gdp.mbigm')
 
+_trusted_solvers = {
+    'gurobi',
+    'cplex',
+    'cbc',
+    'glpk',
+    'scip',
+    'xpress',
+    'mosek',
+    'baron',
+    'highs',
+}
+
 
 @TransformationFactory.register(
     'gdp.mbigm',
@@ -201,9 +212,9 @@ class MultipleBigMTransformation(GDP_to_MIP_Transformation, _BigM_MixIn):
 
     def __init__(self):
         super().__init__(logger)
-        self.handlers[Suffix] = self._warn_for_active_suffix
         self._arg_list = {}
         self._set_up_expr_bound_visitor()
+        self.handlers[Suffix] = self._warn_for_active_suffix
 
     def _apply_to(self, instance, **kwds):
         self.used_args = ComponentMap()
@@ -299,9 +310,12 @@ def _transform_disjunctionData(self, obj, index, parent_disjunct, root_disjunct)
 
         arg_Ms = self._config.bigM if self._config.bigM is not None else {}
 
+        # ESJ: I am relying on the fact that the ComponentSet is going to be
+        # ordered here, but using a set because I will remove infeasible
+        # Disjuncts from it if I encounter them calculating M's.
+        active_disjuncts = ComponentSet(disj for disj in obj.disjuncts if disj.active)
         # First handle the bound constraints if we are dealing with them
         # separately
-        active_disjuncts = [disj for disj in obj.disjuncts if disj.active]
         transformed_constraints = set()
         if self._config.reduce_bound_constraints:
             transformed_constraints = self._transform_bound_constraints(
@@ -325,8 +339,7 @@ def _transform_disjunctionData(self, obj, index, parent_disjunct, root_disjunct)
         for disjunct in active_disjuncts:
             or_expr += disjunct.indicator_var.get_associated_binary()
             self._transform_disjunct(disjunct, transBlock, active_disjuncts, Ms)
-        rhs = 1 if parent_disjunct is None else parent_disjunct.binary_indicator_var
-        algebraic_constraint.add(index, (or_expr, rhs))
+        algebraic_constraint.add(index, or_expr == 1)
         # map the DisjunctionData to its XOR constraint to mark it as
         # transformed
         obj._algebraic_constraint = weakref_ref(algebraic_constraint[index])
@@ -346,17 +359,10 @@ def _transform_disjunct(self, obj, transBlock, active_disjuncts, Ms):
         # deactivate disjunct so writers can be happy
         obj._deactivate_without_fixing_indicator()
 
-    def _warn_for_active_suffix(self, obj, disjunct, active_disjuncts, Ms):
-        raise GDP_Error(
-            "Found active Suffix '{0}' on Disjunct '{1}'. "
-            "The multiple bigM transformation does not currently "
-            "support Suffixes.".format(obj.name, disjunct.name)
-        )
-
     def _transform_constraint(self, obj, disjunct, active_disjuncts, Ms):
         # we will put a new transformed constraint on the relaxation block.
         relaxationBlock = disjunct._transformation_block()
-        constraintMap = relaxationBlock._constraintMap
+        constraint_map = relaxationBlock.private_data('pyomo.gdp')
         transBlock = relaxationBlock.parent_block()
 
         # Though rare, it is possible to get naming conflicts here
@@ -375,7 +381,7 @@ def _transform_constraint(self, obj, disjunct, active_disjuncts, Ms):
                 continue
 
             if not self._config.only_mbigm_bound_constraints:
-                transformed = []
+                transformed = constraint_map.transformed_constraints[c]
                 if c.lower is not None:
                     rhs = sum(
                         Ms[c, disj][0] * disj.indicator_var.get_associated_binary()
@@ -394,8 +400,7 @@ def _transform_constraint(self, obj, disjunct, active_disjuncts, Ms):
                     newConstraint.add((i, 'ub'), c.body - c.upper <= rhs)
                     transformed.append(newConstraint[i, 'ub'])
                 for c_new in transformed:
-                    constraintMap['srcConstraints'][c_new] = [c]
-                constraintMap['transformedConstraints'][c] = transformed
+                    constraint_map.src_constraint[c_new] = [c]
             else:
                 lower = (None, None, None)
                 upper = (None, None, None)
@@ -424,11 +429,11 @@ def _transform_constraint(self, obj, disjunct, active_disjuncts, Ms):
                     M,
                     disjunct.indicator_var.get_associated_binary(),
                     newConstraint,
-                    constraintMap,
+                    constraint_map,
                 )
 
-        # deactivate now that we have transformed
-        c.deactivate()
+            # deactivate now that we have transformed
+            c.deactivate()
 
     def _transform_bound_constraints(self, active_disjuncts, transBlock, Ms):
         # first we're just going to find all of them
@@ -493,6 +498,7 @@ def _transform_bound_constraints(self, active_disjuncts, transBlock, Ms):
                 relaxationBlock = self._get_disjunct_transformation_block(
                     disj, transBlock
                 )
+                constraint_map = relaxationBlock.private_data('pyomo.gdp')
                 if len(lower_dict) > 0:
                     M = lower_dict.get(disj, None)
                     if M is None:
@@ -524,39 +530,24 @@ def _transform_bound_constraints(self, active_disjuncts, transBlock, Ms):
             idx = i + offset
             if len(lower_dict) > 0:
                 transformed.add((idx, 'lb'), v >= lower_rhs)
-                relaxationBlock._constraintMap['srcConstraints'][
-                    transformed[idx, 'lb']
-                ] = []
+                constraint_map.src_constraint[transformed[idx, 'lb']] = []
                 for c, disj in lower_bound_constraints_by_var[v]:
-                    relaxationBlock._constraintMap['srcConstraints'][
-                        transformed[idx, 'lb']
-                    ].append(c)
-                    disj.transformation_block._constraintMap['transformedConstraints'][
-                        c
-                    ] = [transformed[idx, 'lb']]
+                    constraint_map.src_constraint[transformed[idx, 'lb']].append(c)
+                    disj.transformation_block.private_data(
+                        'pyomo.gdp'
+                    ).transformed_constraints[c].append(transformed[idx, 'lb'])
             if len(upper_dict) > 0:
                 transformed.add((idx, 'ub'), v <= upper_rhs)
-                relaxationBlock._constraintMap['srcConstraints'][
-                    transformed[idx, 'ub']
-                ] = []
+                constraint_map.src_constraint[transformed[idx, 'ub']] = []
                 for c, disj in upper_bound_constraints_by_var[v]:
-                    relaxationBlock._constraintMap['srcConstraints'][
-                        transformed[idx, 'ub']
-                    ].append(c)
+                    constraint_map.src_constraint[transformed[idx, 'ub']].append(c)
                     # might already be here if it had an upper bound
-                    if (
-                        c
-                        in disj.transformation_block._constraintMap[
-                            'transformedConstraints'
-                        ]
-                    ):
-                        disj.transformation_block._constraintMap[
-                            'transformedConstraints'
-                        ][c].append(transformed[idx, 'ub'])
-                    else:
-                        disj.transformation_block._constraintMap[
-                            'transformedConstraints'
-                        ][c] = [transformed[idx, 'ub']]
+                    disj_constraint_map = disj.transformation_block.private_data(
+                        'pyomo.gdp'
+                    )
+                    disj_constraint_map.transformed_constraints[c].append(
+                        transformed[idx, 'ub']
+                    )
 
         return transformed_constraints
 
@@ -597,7 +588,7 @@ def _calculate_missing_M_values(
         ):
             if disjunct is other_disjunct:
                 continue
-            if id(other_disjunct) in scratch_blocks:
+            elif id(other_disjunct) in scratch_blocks:
                 scratch = scratch_blocks[id(other_disjunct)]
             else:
                 scratch = scratch_blocks[id(other_disjunct)] = Block()
@@ -631,40 +622,34 @@ def _calculate_missing_M_values(
                     self.used_args[constraint, other_disjunct] = (lower_M, upper_M)
                 else:
                     (lower_M, upper_M) = (None, None)
+                unsuccessful_solve_msg = (
+                    "Unsuccessful solve to calculate M value to "
+                    "relax constraint '%s' on Disjunct '%s' when "
+                    "Disjunct '%s' is selected."
+                    % (constraint.name, disjunct.name, other_disjunct.name)
+                )
                 if constraint.lower is not None and lower_M is None:
                     # last resort: calculate
                     if lower_M is None:
                         scratch.obj.expr = constraint.body - constraint.lower
                         scratch.obj.sense = minimize
-                        results = self._config.solver.solve(other_disjunct)
-                        if (
-                            results.solver.termination_condition
-                            is not TerminationCondition.optimal
-                        ):
-                            raise GDP_Error(
-                                "Unsuccessful solve to calculate M value to "
-                                "relax constraint '%s' on Disjunct '%s' when "
-                                "Disjunct '%s' is selected."
-                                % (constraint.name, disjunct.name, other_disjunct.name)
-                            )
-                        lower_M = value(scratch.obj.expr)
+                        lower_M = self._solve_disjunct_for_M(
+                            other_disjunct,
+                            scratch,
+                            unsuccessful_solve_msg,
+                            active_disjuncts,
+                        )
                 if constraint.upper is not None and upper_M is None:
                     # last resort: calculate
                     if upper_M is None:
                         scratch.obj.expr = constraint.body - constraint.upper
                         scratch.obj.sense = maximize
-                        results = self._config.solver.solve(other_disjunct)
-                        if (
-                            results.solver.termination_condition
-                            is not TerminationCondition.optimal
-                        ):
-                            raise GDP_Error(
-                                "Unsuccessful solve to calculate M value to "
-                                "relax constraint '%s' on Disjunct '%s' when "
-                                "Disjunct '%s' is selected."
-                                % (constraint.name, disjunct.name, other_disjunct.name)
-                            )
-                        upper_M = value(scratch.obj.expr)
+                        upper_M = self._solve_disjunct_for_M(
+                            other_disjunct,
+                            scratch,
+                            unsuccessful_solve_msg,
+                            active_disjuncts,
+                        )
                 arg_Ms[constraint, other_disjunct] = (lower_M, upper_M)
                 transBlock._mbm_values[constraint, other_disjunct] = (lower_M, upper_M)
 
@@ -674,6 +659,70 @@ def _calculate_missing_M_values(
 
         return arg_Ms
 
+    def _solve_disjunct_for_M(
+        self, other_disjunct, scratch_block, unsuccessful_solve_msg, active_disjuncts
+    ):
+        if not other_disjunct.active:
+            # If a Disjunct is infeasible, we will discover that and deactivate
+            # it when we are calculating the M values. We remove that disjunct
+            # from active_disjuncts inside of the loop in
+            # _calculate_missing_M_values. So that means that we might have
+            # deactivated Disjuncts here that we should skip over.
+            return 0
+
+        solver = self._config.solver
+
+        results = solver.solve(other_disjunct, load_solutions=False)
+        if results.solver.termination_condition is TerminationCondition.infeasible:
+            # [2/18/24]: TODO: After the solver rewrite is complete, we will not
+            # need this check since we can actually determine from the
+            # termination condition whether or not the solver proved
+            # infeasibility or just terminated at local infeasiblity. For now,
+            # while this is not complete, it catches most of the solvers we
+            # trust, and, unless someone is so pathological as to *rename* an
+            # untrusted solver using a trusted solver name, it will never do the
+            # *wrong* thing.
+            if any(s in solver.name for s in _trusted_solvers):
+                logger.debug(
+                    "Disjunct '%s' is infeasible, deactivating." % other_disjunct.name
+                )
+                other_disjunct.deactivate()
+                active_disjuncts.remove(other_disjunct)
+                M = 0
+            else:
+                # This is a solver that might report
+                # 'infeasible' for local infeasibility, so we
+                # can't deactivate with confidence. To be
+                # conservative, we'll just complain about
+                # it. Post-solver-rewrite we will want to change
+                # this so that we check for 'proven_infeasible'
+                # and then we can abandon this hack
+                raise GDP_Error(unsuccessful_solve_msg)
+        elif results.solver.termination_condition is not TerminationCondition.optimal:
+            raise GDP_Error(unsuccessful_solve_msg)
+        else:
+            other_disjunct.solutions.load_from(results)
+            M = value(scratch_block.obj.expr)
+        return M
+
+    def _warn_for_active_suffix(self, suffix, disjunct, active_disjuncts, Ms):
+        if suffix.local_name == 'BigM':
+            logger.debug(
+                "Found active 'BigM' Suffix on '{0}'. "
+                "The multiple bigM transformation does not currently "
+                "support specifying M's with Suffixes and is ignoring "
+                "this Suffix.".format(disjunct.name)
+            )
+        elif suffix.local_name == 'LocalVars':
+            # This is fine, but this transformation doesn't need anything from it
+            pass
+        else:
+            raise GDP_Error(
+                "Found active Suffix '{0}' on Disjunct '{1}'. "
+                "The multiple bigM transformation does not "
+                "support this Suffix.".format(suffix.name, disjunct.name)
+            )
+
     # These are all functions to retrieve transformed components from
     # original ones and vice versa.
 
diff --git a/pyomo/gdp/plugins/partition_disjuncts.py b/pyomo/gdp/plugins/partition_disjuncts.py
index fbe25ed3ae1..1a76900047c 100644
--- a/pyomo/gdp/plugins/partition_disjuncts.py
+++ b/pyomo/gdp/plugins/partition_disjuncts.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/gdp/plugins/transform_current_disjunctive_state.py b/pyomo/gdp/plugins/transform_current_disjunctive_state.py
index 338f42c68da..3e20224ec3d 100644
--- a/pyomo/gdp/plugins/transform_current_disjunctive_state.py
+++ b/pyomo/gdp/plugins/transform_current_disjunctive_state.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/gdp/tests/__init__.py b/pyomo/gdp/tests/__init__.py
index c5e495e5aa3..a2a2c61779a 100644
--- a/pyomo/gdp/tests/__init__.py
+++ b/pyomo/gdp/tests/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/gdp/tests/common_tests.py b/pyomo/gdp/tests/common_tests.py
index b475334981b..50bc8b05f86 100644
--- a/pyomo/gdp/tests/common_tests.py
+++ b/pyomo/gdp/tests/common_tests.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -30,7 +30,7 @@
 from pyomo.gdp import Disjunct, Disjunction, GDP_Error
 from pyomo.core.expr.compare import assertExpressionsEqual
 from pyomo.core.base import constraint, ComponentUID
-from pyomo.core.base.block import _BlockData
+from pyomo.core.base.block import BlockData
 from pyomo.repn import generate_standard_repn
 import pyomo.core.expr as EXPR
 import pyomo.gdp.tests.models as models
@@ -58,6 +58,24 @@ def check_linear_coef(self, repn, var, coef):
     self.assertAlmostEqual(repn.linear_coefs[var_id], coef)
 
 
+def check_quadratic_coef(self, repn, v1, v2, coef):
+    if isinstance(v1, BooleanVar):
+        v1 = v1.get_associated_binary()
+    if isinstance(v2, BooleanVar):
+        v2 = v2.get_associated_binary()
+
+    v1id = id(v1)
+    v2id = id(v2)
+
+    qcoef_map = dict()
+    for (_v1, _v2), _coef in zip(repn.quadratic_vars, repn.quadratic_coefs):
+        qcoef_map[id(_v1), id(_v2)] = _coef
+        qcoef_map[id(_v2), id(_v1)] = _coef
+
+    self.assertIn((v1id, v2id), qcoef_map)
+    self.assertAlmostEqual(qcoef_map[v1id, v2id], coef)
+
+
 def check_squared_term_coef(self, repn, var, coef):
     var_id = None
     for i, (v1, v2) in enumerate(repn.quadratic_vars):
@@ -407,12 +425,7 @@ def check_two_term_disjunction_xor(self, xor, disj1, disj2):
     assertExpressionsEqual(
         self,
         xor.body,
-        EXPR.LinearExpression(
-            [
-                EXPR.MonomialTermExpression((1, disj1.binary_indicator_var)),
-                EXPR.MonomialTermExpression((1, disj2.binary_indicator_var)),
-            ]
-        ),
+        EXPR.LinearExpression([disj1.binary_indicator_var, disj2.binary_indicator_var]),
     )
     self.assertEqual(xor.lower, 1)
     self.assertEqual(xor.upper, 1)
@@ -679,32 +692,29 @@ def check_indexedDisj_only_targets_transformed(self, transformation):
             trans.get_transformed_constraints(m.disjunct1[1, 0].c)[0]
             .parent_block()
             .parent_block(),
-            disjBlock[2],
+            disjBlock[0],
         )
         self.assertIs(
             trans.get_transformed_constraints(m.disjunct1[1, 1].c)[0].parent_block(),
-            disjBlock[3],
+            disjBlock[1],
         )
         # In the disaggregated var bounds
         self.assertIs(
             trans.get_transformed_constraints(m.disjunct1[2, 0].c)[0]
             .parent_block()
             .parent_block(),
-            disjBlock[0],
+            disjBlock[2],
         )
         self.assertIs(
             trans.get_transformed_constraints(m.disjunct1[2, 1].c)[0].parent_block(),
-            disjBlock[1],
+            disjBlock[3],
         )
 
     # This relies on the disjunctions being transformed in the same order
     # every time. These are the mappings between the indices of the original
     # disjuncts and the indices on the indexed block on the transformation
     # block.
-    if transformation == 'bigm':
-        pairs = [((1, 0), 0), ((1, 1), 1), ((2, 0), 2), ((2, 1), 3)]
-    elif transformation == 'hull':
-        pairs = [((2, 0), 0), ((2, 1), 1), ((1, 0), 2), ((1, 1), 3)]
+    pairs = [((1, 0), 0), ((1, 1), 1), ((2, 0), 2), ((2, 1), 3)]
 
     for i, j in pairs:
         self.assertIs(trans.get_src_disjunct(disjBlock[j]), m.disjunct1[i])
@@ -942,9 +952,7 @@ def check_disjunction_data_target(self, transformation):
     transBlock = m.component("_pyomo_gdp_%s_reformulation" % transformation)
     self.assertIsInstance(transBlock, Block)
     self.assertIsInstance(transBlock.component("disjunction_xor"), Constraint)
-    self.assertIsInstance(
-        transBlock.disjunction_xor[2], constraint._GeneralConstraintData
-    )
+    self.assertIsInstance(transBlock.disjunction_xor[2], constraint.ConstraintData)
     self.assertIsInstance(transBlock.component("relaxedDisjuncts"), Block)
     self.assertEqual(len(transBlock.relaxedDisjuncts), 3)
 
@@ -953,7 +961,7 @@ def check_disjunction_data_target(self, transformation):
         m, targets=[m.disjunction[1]]
     )
     self.assertIsInstance(
-        m.disjunction[1].algebraic_constraint, constraint._GeneralConstraintData
+        m.disjunction[1].algebraic_constraint, constraint.ConstraintData
     )
     transBlock = m.component("_pyomo_gdp_%s_reformulation_4" % transformation)
     self.assertIsInstance(transBlock, Block)
@@ -1694,26 +1702,78 @@ def check_all_components_transformed(self, m):
     # makeNestedDisjunctions_NestedDisjuncts model.
     self.assertIsInstance(m.disj.algebraic_constraint, Constraint)
     self.assertIsInstance(m.d1.disj2.algebraic_constraint, Constraint)
-    self.assertIsInstance(m.d1.transformation_block, _BlockData)
-    self.assertIsInstance(m.d2.transformation_block, _BlockData)
-    self.assertIsInstance(m.d1.d3.transformation_block, _BlockData)
-    self.assertIsInstance(m.d1.d4.transformation_block, _BlockData)
+    self.assertIsInstance(m.d1.transformation_block, BlockData)
+    self.assertIsInstance(m.d2.transformation_block, BlockData)
+    self.assertIsInstance(m.d1.d3.transformation_block, BlockData)
+    self.assertIsInstance(m.d1.d4.transformation_block, BlockData)
 
 
 def check_transformation_blocks_nestedDisjunctions(self, m, transformation):
     disjunctionTransBlock = m.disj.algebraic_constraint.parent_block()
     transBlocks = disjunctionTransBlock.relaxedDisjuncts
-    self.assertEqual(len(transBlocks), 4)
     if transformation == 'bigm':
+        self.assertEqual(len(transBlocks), 4)
         self.assertIs(transBlocks[0], m.d1.d3.transformation_block)
         self.assertIs(transBlocks[1], m.d1.d4.transformation_block)
         self.assertIs(transBlocks[2], m.d1.transformation_block)
         self.assertIs(transBlocks[3], m.d2.transformation_block)
     if transformation == 'hull':
-        self.assertIs(transBlocks[2], m.d1.d3.transformation_block)
-        self.assertIs(transBlocks[3], m.d1.d4.transformation_block)
-        self.assertIs(transBlocks[0], m.d1.transformation_block)
-        self.assertIs(transBlocks[1], m.d2.transformation_block)
+        # This is a much more comprehensive test that doesn't depend on
+        # transformation Block structure, so just reuse it:
+        hull = TransformationFactory('gdp.hull')
+        d3 = hull.get_disaggregated_var(m.d1.d3.binary_indicator_var, m.d1)
+        d4 = hull.get_disaggregated_var(m.d1.d4.binary_indicator_var, m.d1)
+        self.check_transformed_model_nestedDisjuncts(m, d3, d4)
+
+        # Check the 4 constraints that are unique to the case where we didn't
+        # declare d1.d3 and d1.d4 as local
+        d32 = hull.get_disaggregated_var(m.d1.d3.binary_indicator_var, m.d2)
+        d42 = hull.get_disaggregated_var(m.d1.d4.binary_indicator_var, m.d2)
+        # check the additional disaggregated indicator var bound constraints
+        cons = hull.get_var_bounds_constraint(d32)
+        self.assertEqual(len(cons), 1)
+        check_obj_in_active_tree(self, cons['ub'])
+        cons_expr = self.simplify_leq_cons(cons['ub'])
+        # Note that this comes out as d32 <= 1 - d1.ind_var because it's the
+        # "extra" disaggregated var that gets created when it need to be
+        # disaggregated for d1, but it's not used in d2
+        assertExpressionsEqual(
+            self, cons_expr, d32 + m.d1.binary_indicator_var - 1 <= 0.0
+        )
+
+        cons = hull.get_var_bounds_constraint(d42)
+        self.assertEqual(len(cons), 1)
+        check_obj_in_active_tree(self, cons['ub'])
+        cons_expr = self.simplify_leq_cons(cons['ub'])
+        # Note that this comes out as d42 <= 1 - d1.ind_var because it's the
+        # "extra" disaggregated var that gets created when it need to be
+        # disaggregated for d1, but it's not used in d2
+        assertExpressionsEqual(
+            self, cons_expr, d42 + m.d1.binary_indicator_var - 1 <= 0.0
+        )
+        # check the aggregation constraints for the disaggregated indicator vars
+        cons = hull.get_disaggregation_constraint(m.d1.d3.binary_indicator_var, m.disj)
+        check_obj_in_active_tree(self, cons)
+        cons_expr = self.simplify_cons(cons)
+        assertExpressionsEqual(
+            self, cons_expr, m.d1.d3.binary_indicator_var - d32 - d3 == 0.0
+        )
+        cons = hull.get_disaggregation_constraint(m.d1.d4.binary_indicator_var, m.disj)
+        check_obj_in_active_tree(self, cons)
+        cons_expr = self.simplify_cons(cons)
+        assertExpressionsEqual(
+            self, cons_expr, m.d1.d4.binary_indicator_var - d42 - d4 == 0.0
+        )
+
+        num_cons = len(
+            list(m.component_data_objects(Constraint, active=True, descend_into=Block))
+        )
+        # 30 total constraints in transformed model minus 10 trivial bounds
+        # (lower bounds of 0) gives us 20 constraints total:
+        self.assertEqual(num_cons, 20)
+        # (And this is 4 more than we test in
+        # self.check_transformed_model_nestedDisjuncts, so that's comforting
+        # too.)
 
 
 def check_nested_disjunction_target(self, transformation):
@@ -1877,3 +1937,17 @@ def check_nested_disjuncts_in_flat_gdp(self, transformation):
     for t in m.T:
         self.assertTrue(value(m.disj1[t].indicator_var))
         self.assertTrue(value(m.disj1[t].sub1.indicator_var))
+
+
+def check_do_not_assume_nested_indicators_local(self, transformation):
+    m = models.why_indicator_vars_are_not_always_local()
+    TransformationFactory(transformation).apply_to(m)
+
+    results = SolverFactory('gurobi').solve(m)
+    self.assertEqual(results.solver.termination_condition, TerminationCondition.optimal)
+    self.assertAlmostEqual(value(m.obj), 9)
+    self.assertAlmostEqual(value(m.x), 9)
+    self.assertTrue(value(m.Y2.indicator_var))
+    self.assertFalse(value(m.Y1.indicator_var))
+    self.assertTrue(value(m.Z1.indicator_var))
+    self.assertTrue(value(m.Z1.indicator_var))
diff --git a/pyomo/gdp/tests/jobshop_large_hull.lp b/pyomo/gdp/tests/jobshop_large_hull.lp
index df3833bdee3..f0a9d3ccbf0 100644
--- a/pyomo/gdp/tests/jobshop_large_hull.lp
+++ b/pyomo/gdp/tests/jobshop_large_hull.lp
@@ -42,75 +42,75 @@ c_u_Feas(G)_:
 <= -17
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(0)_:
-+1 t(G)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_disaggregatedVars__t(G)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_disaggregatedVars__t(G)_
++1 t(B)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_disaggregatedVars__t(B)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_disaggregatedVars__t(B)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(1)_:
-+1 t(F)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_disaggregatedVars__t(F)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_disaggregatedVars__t(F)_
++1 t(A)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_disaggregatedVars__t(A)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_disaggregatedVars__t(A)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(2)_:
-+1 t(G)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(2)_disaggregatedVars__t(G)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(3)_disaggregatedVars__t(G)_
++1 t(B)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(2)_disaggregatedVars__t(B)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(3)_disaggregatedVars__t(B)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(3)_:
-+1 t(E)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(2)_disaggregatedVars__t(E)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(3)_disaggregatedVars__t(E)_
++1 t(A)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(2)_disaggregatedVars__t(A)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(3)_disaggregatedVars__t(A)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(4)_:
-+1 t(G)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(G)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(G)_
++1 t(C)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(C)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(C)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(5)_:
-+1 t(E)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(E)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(E)_
++1 t(A)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(A)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(A)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(6)_:
-+1 t(F)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(6)_disaggregatedVars__t(F)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(7)_disaggregatedVars__t(F)_
++1 t(D)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(6)_disaggregatedVars__t(D)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(7)_disaggregatedVars__t(D)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(7)_:
-+1 t(E)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(6)_disaggregatedVars__t(E)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(7)_disaggregatedVars__t(E)_
++1 t(A)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(6)_disaggregatedVars__t(A)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(7)_disaggregatedVars__t(A)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(8)_:
-+1 t(G)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(8)_disaggregatedVars__t(G)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(9)_disaggregatedVars__t(G)_
++1 t(E)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(8)_disaggregatedVars__t(E)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(9)_disaggregatedVars__t(E)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(9)_:
-+1 t(D)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(8)_disaggregatedVars__t(D)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(9)_disaggregatedVars__t(D)_
++1 t(A)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(8)_disaggregatedVars__t(A)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(9)_disaggregatedVars__t(A)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(10)_:
-+1 t(G)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(10)_disaggregatedVars__t(G)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(11)_disaggregatedVars__t(G)_
++1 t(E)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(10)_disaggregatedVars__t(E)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(11)_disaggregatedVars__t(E)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(11)_:
-+1 t(D)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(10)_disaggregatedVars__t(D)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(11)_disaggregatedVars__t(D)_
++1 t(A)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(10)_disaggregatedVars__t(A)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(11)_disaggregatedVars__t(A)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(12)_:
@@ -120,9 +120,9 @@ c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(12)_:
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(13)_:
-+1 t(D)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(12)_disaggregatedVars__t(D)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(13)_disaggregatedVars__t(D)_
++1 t(A)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(12)_disaggregatedVars__t(A)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(13)_disaggregatedVars__t(A)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(14)_:
@@ -132,81 +132,81 @@ c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(14)_:
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(15)_:
-+1 t(D)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(14)_disaggregatedVars__t(D)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(15)_disaggregatedVars__t(D)_
++1 t(A)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(14)_disaggregatedVars__t(A)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(15)_disaggregatedVars__t(A)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(16)_:
-+1 t(E)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(16)_disaggregatedVars__t(E)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(17)_disaggregatedVars__t(E)_
++1 t(G)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(16)_disaggregatedVars__t(G)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(17)_disaggregatedVars__t(G)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(17)_:
-+1 t(D)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(16)_disaggregatedVars__t(D)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(17)_disaggregatedVars__t(D)_
++1 t(A)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(16)_disaggregatedVars__t(A)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(17)_disaggregatedVars__t(A)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(18)_:
-+1 t(E)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(18)_disaggregatedVars__t(E)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(19)_disaggregatedVars__t(E)_
++1 t(C)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(18)_disaggregatedVars__t(C)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(19)_disaggregatedVars__t(C)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(19)_:
-+1 t(D)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(18)_disaggregatedVars__t(D)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(19)_disaggregatedVars__t(D)_
++1 t(B)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(18)_disaggregatedVars__t(B)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(19)_disaggregatedVars__t(B)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(20)_:
-+1 t(G)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(20)_disaggregatedVars__t(G)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(21)_disaggregatedVars__t(G)_
++1 t(D)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(20)_disaggregatedVars__t(D)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(21)_disaggregatedVars__t(D)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(21)_:
-+1 t(C)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(20)_disaggregatedVars__t(C)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(21)_disaggregatedVars__t(C)_
++1 t(B)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(20)_disaggregatedVars__t(B)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(21)_disaggregatedVars__t(B)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(22)_:
-+1 t(G)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(22)_disaggregatedVars__t(G)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(23)_disaggregatedVars__t(G)_
++1 t(D)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(22)_disaggregatedVars__t(D)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(23)_disaggregatedVars__t(D)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(23)_:
-+1 t(C)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(22)_disaggregatedVars__t(C)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(23)_disaggregatedVars__t(C)_
++1 t(B)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(22)_disaggregatedVars__t(B)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(23)_disaggregatedVars__t(B)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(24)_:
-+1 t(F)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(24)_disaggregatedVars__t(F)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(25)_disaggregatedVars__t(F)_
++1 t(E)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(24)_disaggregatedVars__t(E)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(25)_disaggregatedVars__t(E)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(25)_:
-+1 t(C)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(24)_disaggregatedVars__t(C)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(25)_disaggregatedVars__t(C)_
++1 t(B)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(24)_disaggregatedVars__t(B)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(25)_disaggregatedVars__t(B)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(26)_:
-+1 t(F)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(26)_disaggregatedVars__t(F)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(27)_disaggregatedVars__t(F)_
++1 t(E)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(26)_disaggregatedVars__t(E)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(27)_disaggregatedVars__t(E)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(27)_:
-+1 t(C)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(26)_disaggregatedVars__t(C)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(27)_disaggregatedVars__t(C)_
++1 t(B)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(26)_disaggregatedVars__t(B)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(27)_disaggregatedVars__t(B)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(28)_:
@@ -216,33 +216,33 @@ c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(28)_:
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(29)_:
-+1 t(C)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(28)_disaggregatedVars__t(C)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(29)_disaggregatedVars__t(C)_
++1 t(B)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(28)_disaggregatedVars__t(B)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(29)_disaggregatedVars__t(B)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(30)_:
-+1 t(D)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(30)_disaggregatedVars__t(D)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(31)_disaggregatedVars__t(D)_
++1 t(F)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(30)_disaggregatedVars__t(F)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(31)_disaggregatedVars__t(F)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(31)_:
-+1 t(C)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(30)_disaggregatedVars__t(C)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(31)_disaggregatedVars__t(C)_
++1 t(B)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(30)_disaggregatedVars__t(B)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(31)_disaggregatedVars__t(B)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(32)_:
-+1 t(D)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(32)_disaggregatedVars__t(D)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(33)_disaggregatedVars__t(D)_
++1 t(G)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(32)_disaggregatedVars__t(G)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(33)_disaggregatedVars__t(G)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(33)_:
-+1 t(C)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(32)_disaggregatedVars__t(C)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(33)_disaggregatedVars__t(C)_
++1 t(B)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(32)_disaggregatedVars__t(B)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(33)_disaggregatedVars__t(B)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(34)_:
@@ -258,27 +258,27 @@ c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(35)_:
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(36)_:
-+1 t(G)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(36)_disaggregatedVars__t(G)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(37)_disaggregatedVars__t(G)_
++1 t(D)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(36)_disaggregatedVars__t(D)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(37)_disaggregatedVars__t(D)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(37)_:
-+1 t(B)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(36)_disaggregatedVars__t(B)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(37)_disaggregatedVars__t(B)_
++1 t(C)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(36)_disaggregatedVars__t(C)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(37)_disaggregatedVars__t(C)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(38)_:
-+1 t(F)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(38)_disaggregatedVars__t(F)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(39)_disaggregatedVars__t(F)_
++1 t(D)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(38)_disaggregatedVars__t(D)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(39)_disaggregatedVars__t(D)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(39)_:
-+1 t(B)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(38)_disaggregatedVars__t(B)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(39)_disaggregatedVars__t(B)_
++1 t(C)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(38)_disaggregatedVars__t(C)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(39)_disaggregatedVars__t(C)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(40)_:
@@ -288,81 +288,81 @@ c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(40)_:
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(41)_:
-+1 t(B)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(40)_disaggregatedVars__t(B)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(41)_disaggregatedVars__t(B)_
++1 t(C)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(40)_disaggregatedVars__t(C)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(41)_disaggregatedVars__t(C)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(42)_:
-+1 t(E)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(42)_disaggregatedVars__t(E)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(43)_disaggregatedVars__t(E)_
++1 t(F)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(42)_disaggregatedVars__t(F)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(43)_disaggregatedVars__t(F)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(43)_:
-+1 t(B)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(42)_disaggregatedVars__t(B)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(43)_disaggregatedVars__t(B)_
++1 t(C)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(42)_disaggregatedVars__t(C)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(43)_disaggregatedVars__t(C)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(44)_:
-+1 t(E)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(44)_disaggregatedVars__t(E)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(45)_disaggregatedVars__t(E)_
++1 t(F)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(44)_disaggregatedVars__t(F)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(45)_disaggregatedVars__t(F)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(45)_:
-+1 t(B)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(44)_disaggregatedVars__t(B)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(45)_disaggregatedVars__t(B)_
++1 t(C)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(44)_disaggregatedVars__t(C)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(45)_disaggregatedVars__t(C)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(46)_:
-+1 t(D)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(46)_disaggregatedVars__t(D)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(47)_disaggregatedVars__t(D)_
++1 t(G)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(46)_disaggregatedVars__t(G)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(47)_disaggregatedVars__t(G)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(47)_:
-+1 t(B)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(46)_disaggregatedVars__t(B)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(47)_disaggregatedVars__t(B)_
++1 t(C)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(46)_disaggregatedVars__t(C)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(47)_disaggregatedVars__t(C)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(48)_:
-+1 t(D)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(48)_disaggregatedVars__t(D)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(49)_disaggregatedVars__t(D)_
++1 t(G)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(48)_disaggregatedVars__t(G)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(49)_disaggregatedVars__t(G)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(49)_:
-+1 t(B)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(48)_disaggregatedVars__t(B)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(49)_disaggregatedVars__t(B)_
++1 t(C)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(48)_disaggregatedVars__t(C)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(49)_disaggregatedVars__t(C)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(50)_:
-+1 t(C)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(50)_disaggregatedVars__t(C)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(51)_disaggregatedVars__t(C)_
++1 t(E)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(50)_disaggregatedVars__t(E)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(51)_disaggregatedVars__t(E)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(51)_:
-+1 t(B)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(50)_disaggregatedVars__t(B)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(51)_disaggregatedVars__t(B)_
++1 t(D)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(50)_disaggregatedVars__t(D)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(51)_disaggregatedVars__t(D)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(52)_:
-+1 t(G)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(52)_disaggregatedVars__t(G)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(53)_disaggregatedVars__t(G)_
++1 t(E)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(52)_disaggregatedVars__t(E)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(53)_disaggregatedVars__t(E)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(53)_:
-+1 t(A)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(52)_disaggregatedVars__t(A)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(53)_disaggregatedVars__t(A)_
++1 t(D)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(52)_disaggregatedVars__t(D)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(53)_disaggregatedVars__t(D)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(54)_:
@@ -372,9 +372,9 @@ c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(54)_:
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(55)_:
-+1 t(A)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(54)_disaggregatedVars__t(A)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(55)_disaggregatedVars__t(A)_
++1 t(D)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(54)_disaggregatedVars__t(D)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(55)_disaggregatedVars__t(D)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(56)_:
@@ -384,81 +384,81 @@ c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(56)_:
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(57)_:
-+1 t(A)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(56)_disaggregatedVars__t(A)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(57)_disaggregatedVars__t(A)_
++1 t(D)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(56)_disaggregatedVars__t(D)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(57)_disaggregatedVars__t(D)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(58)_:
-+1 t(E)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(58)_disaggregatedVars__t(E)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(59)_disaggregatedVars__t(E)_
++1 t(G)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(58)_disaggregatedVars__t(G)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(59)_disaggregatedVars__t(G)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(59)_:
-+1 t(A)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(58)_disaggregatedVars__t(A)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(59)_disaggregatedVars__t(A)_
++1 t(D)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(58)_disaggregatedVars__t(D)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(59)_disaggregatedVars__t(D)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(60)_:
-+1 t(E)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(60)_disaggregatedVars__t(E)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(61)_disaggregatedVars__t(E)_
++1 t(G)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(60)_disaggregatedVars__t(G)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(61)_disaggregatedVars__t(G)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(61)_:
-+1 t(A)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(60)_disaggregatedVars__t(A)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(61)_disaggregatedVars__t(A)_
++1 t(D)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(60)_disaggregatedVars__t(D)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(61)_disaggregatedVars__t(D)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(62)_:
-+1 t(D)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(62)_disaggregatedVars__t(D)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(63)_disaggregatedVars__t(D)_
++1 t(F)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(62)_disaggregatedVars__t(F)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(63)_disaggregatedVars__t(F)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(63)_:
-+1 t(A)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(62)_disaggregatedVars__t(A)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(63)_disaggregatedVars__t(A)_
++1 t(E)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(62)_disaggregatedVars__t(E)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(63)_disaggregatedVars__t(E)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(64)_:
-+1 t(C)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(64)_disaggregatedVars__t(C)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(65)_disaggregatedVars__t(C)_
++1 t(G)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(64)_disaggregatedVars__t(G)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(65)_disaggregatedVars__t(G)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(65)_:
-+1 t(A)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(64)_disaggregatedVars__t(A)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(65)_disaggregatedVars__t(A)_
++1 t(E)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(64)_disaggregatedVars__t(E)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(65)_disaggregatedVars__t(E)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(66)_:
-+1 t(B)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(66)_disaggregatedVars__t(B)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(67)_disaggregatedVars__t(B)_
++1 t(G)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(66)_disaggregatedVars__t(G)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(67)_disaggregatedVars__t(G)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(67)_:
-+1 t(A)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(66)_disaggregatedVars__t(A)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(67)_disaggregatedVars__t(A)_
++1 t(E)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(66)_disaggregatedVars__t(E)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(67)_disaggregatedVars__t(E)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(68)_:
-+1 t(B)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(68)_disaggregatedVars__t(B)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(69)_disaggregatedVars__t(B)_
++1 t(G)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(68)_disaggregatedVars__t(G)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(69)_disaggregatedVars__t(G)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(69)_:
-+1 t(A)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(68)_disaggregatedVars__t(A)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(69)_disaggregatedVars__t(A)_
++1 t(F)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(68)_disaggregatedVars__t(F)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(69)_disaggregatedVars__t(F)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disj_xor(A_B_3)_:
@@ -637,546 +637,544 @@ c_e__pyomo_gdp_hull_reformulation_disj_xor(F_G_4)_:
 = 1
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_transformedConstraints(c_0_ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_disaggregatedVars__t(G)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_disaggregatedVars__t(F)_
-+6.0 NoClash(F_G_4_0)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_disaggregatedVars__t(B)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_disaggregatedVars__t(A)_
++4.0 NoClash(A_B_3_0)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)__t(G)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_disaggregatedVars__t(G)_
--92 NoClash(F_G_4_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)__t(B)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_disaggregatedVars__t(B)_
+-92 NoClash(A_B_3_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)__t(F)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_disaggregatedVars__t(F)_
--92 NoClash(F_G_4_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)__t(A)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_disaggregatedVars__t(A)_
+-92 NoClash(A_B_3_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_transformedConstraints(c_0_ub)_:
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_disaggregatedVars__t(G)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_disaggregatedVars__t(F)_
-+6.0 NoClash(F_G_4_1)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_disaggregatedVars__t(B)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_disaggregatedVars__t(A)_
++5.0 NoClash(A_B_3_1)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)__t(G)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_disaggregatedVars__t(G)_
--92 NoClash(F_G_4_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)__t(B)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_disaggregatedVars__t(B)_
+-92 NoClash(A_B_3_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)__t(F)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_disaggregatedVars__t(F)_
--92 NoClash(F_G_4_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)__t(A)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_disaggregatedVars__t(A)_
+-92 NoClash(A_B_3_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(2)_transformedConstraints(c_0_ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(2)_disaggregatedVars__t(G)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(2)_disaggregatedVars__t(E)_
-+7.0 NoClash(E_G_5_0)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(2)_disaggregatedVars__t(B)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(2)_disaggregatedVars__t(A)_
++2.0 NoClash(A_B_5_0)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(2)__t(G)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(2)_disaggregatedVars__t(G)_
--92 NoClash(E_G_5_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(2)__t(B)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(2)_disaggregatedVars__t(B)_
+-92 NoClash(A_B_5_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(2)__t(E)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(2)_disaggregatedVars__t(E)_
--92 NoClash(E_G_5_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(2)__t(A)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(2)_disaggregatedVars__t(A)_
+-92 NoClash(A_B_5_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(3)_transformedConstraints(c_0_ub)_:
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(3)_disaggregatedVars__t(G)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(3)_disaggregatedVars__t(E)_
--1 NoClash(E_G_5_1)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(3)_disaggregatedVars__t(B)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(3)_disaggregatedVars__t(A)_
++3.0 NoClash(A_B_5_1)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(3)__t(G)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(3)_disaggregatedVars__t(G)_
--92 NoClash(E_G_5_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(3)__t(B)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(3)_disaggregatedVars__t(B)_
+-92 NoClash(A_B_5_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(3)__t(E)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(3)_disaggregatedVars__t(E)_
--92 NoClash(E_G_5_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(3)__t(A)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(3)_disaggregatedVars__t(A)_
+-92 NoClash(A_B_5_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_transformedConstraints(c_0_ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(G)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(E)_
-+8.0 NoClash(E_G_2_0)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(C)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(A)_
++6.0 NoClash(A_C_1_0)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)__t(G)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(G)_
--92 NoClash(E_G_2_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)__t(C)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(C)_
+-92 NoClash(A_C_1_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)__t(E)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(E)_
--92 NoClash(E_G_2_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)__t(A)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(A)_
+-92 NoClash(A_C_1_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_transformedConstraints(c_0_ub)_:
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(G)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(E)_
-+4.0 NoClash(E_G_2_1)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(C)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(A)_
++3.0 NoClash(A_C_1_1)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)__t(G)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(G)_
--92 NoClash(E_G_2_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)__t(C)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(C)_
+-92 NoClash(A_C_1_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)__t(E)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(E)_
--92 NoClash(E_G_2_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)__t(A)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(A)_
+-92 NoClash(A_C_1_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(6)_transformedConstraints(c_0_ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(6)_disaggregatedVars__t(F)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(6)_disaggregatedVars__t(E)_
-+3.0 NoClash(E_F_3_0)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(6)_disaggregatedVars__t(D)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(6)_disaggregatedVars__t(A)_
++10.0 NoClash(A_D_3_0)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(6)__t(F)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(6)_disaggregatedVars__t(F)_
--92 NoClash(E_F_3_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(6)__t(D)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(6)_disaggregatedVars__t(D)_
+-92 NoClash(A_D_3_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(6)__t(E)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(6)_disaggregatedVars__t(E)_
--92 NoClash(E_F_3_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(6)__t(A)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(6)_disaggregatedVars__t(A)_
+-92 NoClash(A_D_3_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(7)_transformedConstraints(c_0_ub)_:
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(7)_disaggregatedVars__t(F)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(7)_disaggregatedVars__t(E)_
-+8.0 NoClash(E_F_3_1)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(7)_disaggregatedVars__t(D)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(7)_disaggregatedVars__t(A)_
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(7)__t(F)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(7)_disaggregatedVars__t(F)_
--92 NoClash(E_F_3_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(7)__t(D)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(7)_disaggregatedVars__t(D)_
+-92 NoClash(A_D_3_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(7)__t(E)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(7)_disaggregatedVars__t(E)_
--92 NoClash(E_F_3_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(7)__t(A)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(7)_disaggregatedVars__t(A)_
+-92 NoClash(A_D_3_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(8)_transformedConstraints(c_0_ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(8)_disaggregatedVars__t(G)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(8)_disaggregatedVars__t(D)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(8)_disaggregatedVars__t(E)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(8)_disaggregatedVars__t(A)_
++7.0 NoClash(A_E_3_0)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(8)__t(G)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(8)_disaggregatedVars__t(G)_
--92 NoClash(D_G_4_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(8)__t(E)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(8)_disaggregatedVars__t(E)_
+-92 NoClash(A_E_3_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(8)__t(D)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(8)_disaggregatedVars__t(D)_
--92 NoClash(D_G_4_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(8)__t(A)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(8)_disaggregatedVars__t(A)_
+-92 NoClash(A_E_3_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(9)_transformedConstraints(c_0_ub)_:
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(9)_disaggregatedVars__t(G)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(9)_disaggregatedVars__t(D)_
-+6.0 NoClash(D_G_4_1)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(9)_disaggregatedVars__t(E)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(9)_disaggregatedVars__t(A)_
++4.0 NoClash(A_E_3_1)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(9)__t(G)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(9)_disaggregatedVars__t(G)_
--92 NoClash(D_G_4_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(9)__t(E)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(9)_disaggregatedVars__t(E)_
+-92 NoClash(A_E_3_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(9)__t(D)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(9)_disaggregatedVars__t(D)_
--92 NoClash(D_G_4_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(9)__t(A)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(9)_disaggregatedVars__t(A)_
+-92 NoClash(A_E_3_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(10)_transformedConstraints(c_0_ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(10)_disaggregatedVars__t(G)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(10)_disaggregatedVars__t(D)_
-+8.0 NoClash(D_G_2_0)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(10)_disaggregatedVars__t(E)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(10)_disaggregatedVars__t(A)_
++4.0 NoClash(A_E_5_0)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(10)__t(G)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(10)_disaggregatedVars__t(G)_
--92 NoClash(D_G_2_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(10)__t(E)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(10)_disaggregatedVars__t(E)_
+-92 NoClash(A_E_5_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(10)__t(D)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(10)_disaggregatedVars__t(D)_
--92 NoClash(D_G_2_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(10)__t(A)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(10)_disaggregatedVars__t(A)_
+-92 NoClash(A_E_5_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(11)_transformedConstraints(c_0_ub)_:
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(11)_disaggregatedVars__t(G)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(11)_disaggregatedVars__t(D)_
-+8.0 NoClash(D_G_2_1)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(11)_disaggregatedVars__t(E)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(11)_disaggregatedVars__t(A)_
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(11)__t(G)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(11)_disaggregatedVars__t(G)_
--92 NoClash(D_G_2_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(11)__t(E)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(11)_disaggregatedVars__t(E)_
+-92 NoClash(A_E_5_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(11)__t(D)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(11)_disaggregatedVars__t(D)_
--92 NoClash(D_G_2_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(11)__t(A)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(11)_disaggregatedVars__t(A)_
+-92 NoClash(A_E_5_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(12)_transformedConstraints(c_0_ub)_:
 +1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(12)_disaggregatedVars__t(F)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(12)_disaggregatedVars__t(D)_
-+1 NoClash(D_F_4_0)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(12)_disaggregatedVars__t(A)_
++2.0 NoClash(A_F_1_0)_binary_indicator_var
 <= 0.0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(12)__t(F)_bounds_(ub)_:
 +1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(12)_disaggregatedVars__t(F)_
--92 NoClash(D_F_4_0)_binary_indicator_var
+-92 NoClash(A_F_1_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(12)__t(D)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(12)_disaggregatedVars__t(D)_
--92 NoClash(D_F_4_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(12)__t(A)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(12)_disaggregatedVars__t(A)_
+-92 NoClash(A_F_1_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(13)_transformedConstraints(c_0_ub)_:
 -1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(13)_disaggregatedVars__t(F)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(13)_disaggregatedVars__t(D)_
-+7.0 NoClash(D_F_4_1)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(13)_disaggregatedVars__t(A)_
++3.0 NoClash(A_F_1_1)_binary_indicator_var
 <= 0.0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(13)__t(F)_bounds_(ub)_:
 +1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(13)_disaggregatedVars__t(F)_
--92 NoClash(D_F_4_1)_binary_indicator_var
+-92 NoClash(A_F_1_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(13)__t(D)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(13)_disaggregatedVars__t(D)_
--92 NoClash(D_F_4_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(13)__t(A)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(13)_disaggregatedVars__t(A)_
+-92 NoClash(A_F_1_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(14)_transformedConstraints(c_0_ub)_:
 +1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(14)_disaggregatedVars__t(F)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(14)_disaggregatedVars__t(D)_
--1 NoClash(D_F_3_0)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(14)_disaggregatedVars__t(A)_
++4.0 NoClash(A_F_3_0)_binary_indicator_var
 <= 0.0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(14)__t(F)_bounds_(ub)_:
 +1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(14)_disaggregatedVars__t(F)_
--92 NoClash(D_F_3_0)_binary_indicator_var
+-92 NoClash(A_F_3_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(14)__t(D)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(14)_disaggregatedVars__t(D)_
--92 NoClash(D_F_3_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(14)__t(A)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(14)_disaggregatedVars__t(A)_
+-92 NoClash(A_F_3_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(15)_transformedConstraints(c_0_ub)_:
 -1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(15)_disaggregatedVars__t(F)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(15)_disaggregatedVars__t(D)_
-+11.0 NoClash(D_F_3_1)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(15)_disaggregatedVars__t(A)_
++6.0 NoClash(A_F_3_1)_binary_indicator_var
 <= 0.0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(15)__t(F)_bounds_(ub)_:
 +1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(15)_disaggregatedVars__t(F)_
--92 NoClash(D_F_3_1)_binary_indicator_var
+-92 NoClash(A_F_3_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(15)__t(D)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(15)_disaggregatedVars__t(D)_
--92 NoClash(D_F_3_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(15)__t(A)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(15)_disaggregatedVars__t(A)_
+-92 NoClash(A_F_3_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(16)_transformedConstraints(c_0_ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(16)_disaggregatedVars__t(E)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(16)_disaggregatedVars__t(D)_
-+2.0 NoClash(D_E_3_0)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(16)_disaggregatedVars__t(G)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(16)_disaggregatedVars__t(A)_
++9.0 NoClash(A_G_5_0)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(16)__t(E)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(16)_disaggregatedVars__t(E)_
--92 NoClash(D_E_3_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(16)__t(G)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(16)_disaggregatedVars__t(G)_
+-92 NoClash(A_G_5_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(16)__t(D)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(16)_disaggregatedVars__t(D)_
--92 NoClash(D_E_3_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(16)__t(A)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(16)_disaggregatedVars__t(A)_
+-92 NoClash(A_G_5_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(17)_transformedConstraints(c_0_ub)_:
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(17)_disaggregatedVars__t(E)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(17)_disaggregatedVars__t(D)_
-+9.0 NoClash(D_E_3_1)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(17)_disaggregatedVars__t(G)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(17)_disaggregatedVars__t(A)_
+-3.0 NoClash(A_G_5_1)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(17)__t(E)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(17)_disaggregatedVars__t(E)_
--92 NoClash(D_E_3_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(17)__t(G)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(17)_disaggregatedVars__t(G)_
+-92 NoClash(A_G_5_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(17)__t(D)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(17)_disaggregatedVars__t(D)_
--92 NoClash(D_E_3_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(17)__t(A)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(17)_disaggregatedVars__t(A)_
+-92 NoClash(A_G_5_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(18)_transformedConstraints(c_0_ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(18)_disaggregatedVars__t(E)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(18)_disaggregatedVars__t(D)_
-+4.0 NoClash(D_E_2_0)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(18)_disaggregatedVars__t(C)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(18)_disaggregatedVars__t(B)_
++9.0 NoClash(B_C_2_0)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(18)__t(E)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(18)_disaggregatedVars__t(E)_
--92 NoClash(D_E_2_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(18)__t(C)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(18)_disaggregatedVars__t(C)_
+-92 NoClash(B_C_2_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(18)__t(D)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(18)_disaggregatedVars__t(D)_
--92 NoClash(D_E_2_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(18)__t(B)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(18)_disaggregatedVars__t(B)_
+-92 NoClash(B_C_2_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(19)_transformedConstraints(c_0_ub)_:
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(19)_disaggregatedVars__t(E)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(19)_disaggregatedVars__t(D)_
-+8.0 NoClash(D_E_2_1)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(19)_disaggregatedVars__t(C)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(19)_disaggregatedVars__t(B)_
+-3.0 NoClash(B_C_2_1)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(19)__t(E)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(19)_disaggregatedVars__t(E)_
--92 NoClash(D_E_2_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(19)__t(C)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(19)_disaggregatedVars__t(C)_
+-92 NoClash(B_C_2_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(19)__t(D)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(19)_disaggregatedVars__t(D)_
--92 NoClash(D_E_2_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(19)__t(B)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(19)_disaggregatedVars__t(B)_
+-92 NoClash(B_C_2_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(20)_transformedConstraints(c_0_ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(20)_disaggregatedVars__t(G)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(20)_disaggregatedVars__t(C)_
-+4.0 NoClash(C_G_4_0)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(20)_disaggregatedVars__t(D)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(20)_disaggregatedVars__t(B)_
++8.0 NoClash(B_D_2_0)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(20)__t(G)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(20)_disaggregatedVars__t(G)_
--92 NoClash(C_G_4_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(20)__t(D)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(20)_disaggregatedVars__t(D)_
+-92 NoClash(B_D_2_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(20)__t(C)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(20)_disaggregatedVars__t(C)_
--92 NoClash(C_G_4_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(20)__t(B)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(20)_disaggregatedVars__t(B)_
+-92 NoClash(B_D_2_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(21)_transformedConstraints(c_0_ub)_:
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(21)_disaggregatedVars__t(G)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(21)_disaggregatedVars__t(C)_
-+7.0 NoClash(C_G_4_1)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(21)_disaggregatedVars__t(D)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(21)_disaggregatedVars__t(B)_
++3.0 NoClash(B_D_2_1)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(21)__t(G)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(21)_disaggregatedVars__t(G)_
--92 NoClash(C_G_4_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(21)__t(D)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(21)_disaggregatedVars__t(D)_
+-92 NoClash(B_D_2_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(21)__t(C)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(21)_disaggregatedVars__t(C)_
--92 NoClash(C_G_4_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(21)__t(B)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(21)_disaggregatedVars__t(B)_
+-92 NoClash(B_D_2_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(22)_transformedConstraints(c_0_ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(22)_disaggregatedVars__t(G)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(22)_disaggregatedVars__t(C)_
-+2.0 NoClash(C_G_2_0)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(22)_disaggregatedVars__t(D)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(22)_disaggregatedVars__t(B)_
++10.0 NoClash(B_D_3_0)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(22)__t(G)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(22)_disaggregatedVars__t(G)_
--92 NoClash(C_G_2_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(22)__t(D)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(22)_disaggregatedVars__t(D)_
+-92 NoClash(B_D_3_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(22)__t(C)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(22)_disaggregatedVars__t(C)_
--92 NoClash(C_G_2_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(22)__t(B)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(22)_disaggregatedVars__t(B)_
+-92 NoClash(B_D_3_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(23)_transformedConstraints(c_0_ub)_:
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(23)_disaggregatedVars__t(G)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(23)_disaggregatedVars__t(C)_
-+9.0 NoClash(C_G_2_1)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(23)_disaggregatedVars__t(D)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(23)_disaggregatedVars__t(B)_
+-1 NoClash(B_D_3_1)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(23)__t(G)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(23)_disaggregatedVars__t(G)_
--92 NoClash(C_G_2_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(23)__t(D)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(23)_disaggregatedVars__t(D)_
+-92 NoClash(B_D_3_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(23)__t(C)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(23)_disaggregatedVars__t(C)_
--92 NoClash(C_G_2_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(23)__t(B)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(23)_disaggregatedVars__t(B)_
+-92 NoClash(B_D_3_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(24)_transformedConstraints(c_0_ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(24)_disaggregatedVars__t(F)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(24)_disaggregatedVars__t(C)_
-+5.0 NoClash(C_F_4_0)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(24)_disaggregatedVars__t(E)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(24)_disaggregatedVars__t(B)_
++4.0 NoClash(B_E_2_0)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(24)__t(F)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(24)_disaggregatedVars__t(F)_
--92 NoClash(C_F_4_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(24)__t(E)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(24)_disaggregatedVars__t(E)_
+-92 NoClash(B_E_2_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(24)__t(C)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(24)_disaggregatedVars__t(C)_
--92 NoClash(C_F_4_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(24)__t(B)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(24)_disaggregatedVars__t(B)_
+-92 NoClash(B_E_2_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(25)_transformedConstraints(c_0_ub)_:
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(25)_disaggregatedVars__t(F)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(25)_disaggregatedVars__t(C)_
-+8.0 NoClash(C_F_4_1)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(25)_disaggregatedVars__t(E)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(25)_disaggregatedVars__t(B)_
++3.0 NoClash(B_E_2_1)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(25)__t(F)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(25)_disaggregatedVars__t(F)_
--92 NoClash(C_F_4_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(25)__t(E)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(25)_disaggregatedVars__t(E)_
+-92 NoClash(B_E_2_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(25)__t(C)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(25)_disaggregatedVars__t(C)_
--92 NoClash(C_F_4_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(25)__t(B)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(25)_disaggregatedVars__t(B)_
+-92 NoClash(B_E_2_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(26)_transformedConstraints(c_0_ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(26)_disaggregatedVars__t(F)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(26)_disaggregatedVars__t(C)_
-+2.0 NoClash(C_F_1_0)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(26)_disaggregatedVars__t(E)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(26)_disaggregatedVars__t(B)_
++7.0 NoClash(B_E_3_0)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(26)__t(F)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(26)_disaggregatedVars__t(F)_
--92 NoClash(C_F_1_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(26)__t(E)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(26)_disaggregatedVars__t(E)_
+-92 NoClash(B_E_3_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(26)__t(C)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(26)_disaggregatedVars__t(C)_
--92 NoClash(C_F_1_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(26)__t(B)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(26)_disaggregatedVars__t(B)_
+-92 NoClash(B_E_3_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(27)_transformedConstraints(c_0_ub)_:
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(27)_disaggregatedVars__t(F)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(27)_disaggregatedVars__t(C)_
-+6.0 NoClash(C_F_1_1)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(27)_disaggregatedVars__t(E)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(27)_disaggregatedVars__t(B)_
++3.0 NoClash(B_E_3_1)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(27)__t(F)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(27)_disaggregatedVars__t(F)_
--92 NoClash(C_F_1_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(27)__t(E)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(27)_disaggregatedVars__t(E)_
+-92 NoClash(B_E_3_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(27)__t(C)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(27)_disaggregatedVars__t(C)_
--92 NoClash(C_F_1_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(27)__t(B)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(27)_disaggregatedVars__t(B)_
+-92 NoClash(B_E_3_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(28)_transformedConstraints(c_0_ub)_:
 +1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(28)_disaggregatedVars__t(E)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(28)_disaggregatedVars__t(C)_
--2.0 NoClash(C_E_2_0)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(28)_disaggregatedVars__t(B)_
++5.0 NoClash(B_E_5_0)_binary_indicator_var
 <= 0.0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(28)__t(E)_bounds_(ub)_:
 +1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(28)_disaggregatedVars__t(E)_
--92 NoClash(C_E_2_0)_binary_indicator_var
+-92 NoClash(B_E_5_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(28)__t(C)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(28)_disaggregatedVars__t(C)_
--92 NoClash(C_E_2_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(28)__t(B)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(28)_disaggregatedVars__t(B)_
+-92 NoClash(B_E_5_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(29)_transformedConstraints(c_0_ub)_:
 -1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(29)_disaggregatedVars__t(E)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(29)_disaggregatedVars__t(C)_
-+9.0 NoClash(C_E_2_1)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(29)_disaggregatedVars__t(B)_
 <= 0.0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(29)__t(E)_bounds_(ub)_:
 +1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(29)_disaggregatedVars__t(E)_
--92 NoClash(C_E_2_1)_binary_indicator_var
+-92 NoClash(B_E_5_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(29)__t(C)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(29)_disaggregatedVars__t(C)_
--92 NoClash(C_E_2_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(29)__t(B)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(29)_disaggregatedVars__t(B)_
+-92 NoClash(B_E_5_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(30)_transformedConstraints(c_0_ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(30)_disaggregatedVars__t(D)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(30)_disaggregatedVars__t(C)_
-+5.0 NoClash(C_D_4_0)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(30)_disaggregatedVars__t(F)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(30)_disaggregatedVars__t(B)_
++4.0 NoClash(B_F_3_0)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(30)__t(D)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(30)_disaggregatedVars__t(D)_
--92 NoClash(C_D_4_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(30)__t(F)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(30)_disaggregatedVars__t(F)_
+-92 NoClash(B_F_3_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(30)__t(C)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(30)_disaggregatedVars__t(C)_
--92 NoClash(C_D_4_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(30)__t(B)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(30)_disaggregatedVars__t(B)_
+-92 NoClash(B_F_3_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(31)_transformedConstraints(c_0_ub)_:
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(31)_disaggregatedVars__t(D)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(31)_disaggregatedVars__t(C)_
-+2.0 NoClash(C_D_4_1)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(31)_disaggregatedVars__t(F)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(31)_disaggregatedVars__t(B)_
++5.0 NoClash(B_F_3_1)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(31)__t(D)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(31)_disaggregatedVars__t(D)_
--92 NoClash(C_D_4_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(31)__t(F)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(31)_disaggregatedVars__t(F)_
+-92 NoClash(B_F_3_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(31)__t(C)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(31)_disaggregatedVars__t(C)_
--92 NoClash(C_D_4_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(31)__t(B)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(31)_disaggregatedVars__t(B)_
+-92 NoClash(B_F_3_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(32)_transformedConstraints(c_0_ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(32)_disaggregatedVars__t(D)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(32)_disaggregatedVars__t(C)_
-+2.0 NoClash(C_D_2_0)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(32)_disaggregatedVars__t(G)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(32)_disaggregatedVars__t(B)_
++8.0 NoClash(B_G_2_0)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(32)__t(D)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(32)_disaggregatedVars__t(D)_
--92 NoClash(C_D_2_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(32)__t(G)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(32)_disaggregatedVars__t(G)_
+-92 NoClash(B_G_2_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(32)__t(C)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(32)_disaggregatedVars__t(C)_
--92 NoClash(C_D_2_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(32)__t(B)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(32)_disaggregatedVars__t(B)_
+-92 NoClash(B_G_2_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(33)_transformedConstraints(c_0_ub)_:
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(33)_disaggregatedVars__t(D)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(33)_disaggregatedVars__t(C)_
-+9.0 NoClash(C_D_2_1)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(33)_disaggregatedVars__t(G)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(33)_disaggregatedVars__t(B)_
++3.0 NoClash(B_G_2_1)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(33)__t(D)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(33)_disaggregatedVars__t(D)_
--92 NoClash(C_D_2_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(33)__t(G)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(33)_disaggregatedVars__t(G)_
+-92 NoClash(B_G_2_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(33)__t(C)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(33)_disaggregatedVars__t(C)_
--92 NoClash(C_D_2_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(33)__t(B)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(33)_disaggregatedVars__t(B)_
+-92 NoClash(B_G_2_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(34)_transformedConstraints(c_0_ub)_:
@@ -1212,544 +1210,546 @@ c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(35)__t(B)_bounds_(ub)_:
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(36)_transformedConstraints(c_0_ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(36)_disaggregatedVars__t(G)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(36)_disaggregatedVars__t(B)_
-+8.0 NoClash(B_G_2_0)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(36)_disaggregatedVars__t(D)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(36)_disaggregatedVars__t(C)_
++2.0 NoClash(C_D_2_0)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(36)__t(G)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(36)_disaggregatedVars__t(G)_
--92 NoClash(B_G_2_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(36)__t(D)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(36)_disaggregatedVars__t(D)_
+-92 NoClash(C_D_2_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(36)__t(B)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(36)_disaggregatedVars__t(B)_
--92 NoClash(B_G_2_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(36)__t(C)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(36)_disaggregatedVars__t(C)_
+-92 NoClash(C_D_2_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(37)_transformedConstraints(c_0_ub)_:
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(37)_disaggregatedVars__t(G)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(37)_disaggregatedVars__t(B)_
-+3.0 NoClash(B_G_2_1)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(37)_disaggregatedVars__t(D)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(37)_disaggregatedVars__t(C)_
++9.0 NoClash(C_D_2_1)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(37)__t(G)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(37)_disaggregatedVars__t(G)_
--92 NoClash(B_G_2_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(37)__t(D)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(37)_disaggregatedVars__t(D)_
+-92 NoClash(C_D_2_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(37)__t(B)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(37)_disaggregatedVars__t(B)_
--92 NoClash(B_G_2_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(37)__t(C)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(37)_disaggregatedVars__t(C)_
+-92 NoClash(C_D_2_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(38)_transformedConstraints(c_0_ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(38)_disaggregatedVars__t(F)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(38)_disaggregatedVars__t(B)_
-+4.0 NoClash(B_F_3_0)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(38)_disaggregatedVars__t(D)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(38)_disaggregatedVars__t(C)_
++5.0 NoClash(C_D_4_0)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(38)__t(F)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(38)_disaggregatedVars__t(F)_
--92 NoClash(B_F_3_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(38)__t(D)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(38)_disaggregatedVars__t(D)_
+-92 NoClash(C_D_4_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(38)__t(B)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(38)_disaggregatedVars__t(B)_
--92 NoClash(B_F_3_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(38)__t(C)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(38)_disaggregatedVars__t(C)_
+-92 NoClash(C_D_4_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(39)_transformedConstraints(c_0_ub)_:
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(39)_disaggregatedVars__t(F)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(39)_disaggregatedVars__t(B)_
-+5.0 NoClash(B_F_3_1)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(39)_disaggregatedVars__t(D)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(39)_disaggregatedVars__t(C)_
++2.0 NoClash(C_D_4_1)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(39)__t(F)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(39)_disaggregatedVars__t(F)_
--92 NoClash(B_F_3_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(39)__t(D)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(39)_disaggregatedVars__t(D)_
+-92 NoClash(C_D_4_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(39)__t(B)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(39)_disaggregatedVars__t(B)_
--92 NoClash(B_F_3_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(39)__t(C)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(39)_disaggregatedVars__t(C)_
+-92 NoClash(C_D_4_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(40)_transformedConstraints(c_0_ub)_:
 +1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(40)_disaggregatedVars__t(E)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(40)_disaggregatedVars__t(B)_
-+5.0 NoClash(B_E_5_0)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(40)_disaggregatedVars__t(C)_
+-2.0 NoClash(C_E_2_0)_binary_indicator_var
 <= 0.0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(40)__t(E)_bounds_(ub)_:
 +1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(40)_disaggregatedVars__t(E)_
--92 NoClash(B_E_5_0)_binary_indicator_var
+-92 NoClash(C_E_2_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(40)__t(B)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(40)_disaggregatedVars__t(B)_
--92 NoClash(B_E_5_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(40)__t(C)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(40)_disaggregatedVars__t(C)_
+-92 NoClash(C_E_2_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(41)_transformedConstraints(c_0_ub)_:
 -1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(41)_disaggregatedVars__t(E)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(41)_disaggregatedVars__t(B)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(41)_disaggregatedVars__t(C)_
++9.0 NoClash(C_E_2_1)_binary_indicator_var
 <= 0.0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(41)__t(E)_bounds_(ub)_:
 +1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(41)_disaggregatedVars__t(E)_
--92 NoClash(B_E_5_1)_binary_indicator_var
+-92 NoClash(C_E_2_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(41)__t(B)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(41)_disaggregatedVars__t(B)_
--92 NoClash(B_E_5_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(41)__t(C)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(41)_disaggregatedVars__t(C)_
+-92 NoClash(C_E_2_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(42)_transformedConstraints(c_0_ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(42)_disaggregatedVars__t(E)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(42)_disaggregatedVars__t(B)_
-+7.0 NoClash(B_E_3_0)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(42)_disaggregatedVars__t(F)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(42)_disaggregatedVars__t(C)_
++2.0 NoClash(C_F_1_0)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(42)__t(E)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(42)_disaggregatedVars__t(E)_
--92 NoClash(B_E_3_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(42)__t(F)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(42)_disaggregatedVars__t(F)_
+-92 NoClash(C_F_1_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(42)__t(B)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(42)_disaggregatedVars__t(B)_
--92 NoClash(B_E_3_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(42)__t(C)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(42)_disaggregatedVars__t(C)_
+-92 NoClash(C_F_1_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(43)_transformedConstraints(c_0_ub)_:
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(43)_disaggregatedVars__t(E)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(43)_disaggregatedVars__t(B)_
-+3.0 NoClash(B_E_3_1)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(43)_disaggregatedVars__t(F)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(43)_disaggregatedVars__t(C)_
++6.0 NoClash(C_F_1_1)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(43)__t(E)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(43)_disaggregatedVars__t(E)_
--92 NoClash(B_E_3_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(43)__t(F)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(43)_disaggregatedVars__t(F)_
+-92 NoClash(C_F_1_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(43)__t(B)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(43)_disaggregatedVars__t(B)_
--92 NoClash(B_E_3_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(43)__t(C)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(43)_disaggregatedVars__t(C)_
+-92 NoClash(C_F_1_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(44)_transformedConstraints(c_0_ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(44)_disaggregatedVars__t(E)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(44)_disaggregatedVars__t(B)_
-+4.0 NoClash(B_E_2_0)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(44)_disaggregatedVars__t(F)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(44)_disaggregatedVars__t(C)_
++5.0 NoClash(C_F_4_0)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(44)__t(E)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(44)_disaggregatedVars__t(E)_
--92 NoClash(B_E_2_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(44)__t(F)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(44)_disaggregatedVars__t(F)_
+-92 NoClash(C_F_4_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(44)__t(B)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(44)_disaggregatedVars__t(B)_
--92 NoClash(B_E_2_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(44)__t(C)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(44)_disaggregatedVars__t(C)_
+-92 NoClash(C_F_4_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(45)_transformedConstraints(c_0_ub)_:
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(45)_disaggregatedVars__t(E)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(45)_disaggregatedVars__t(B)_
-+3.0 NoClash(B_E_2_1)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(45)_disaggregatedVars__t(F)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(45)_disaggregatedVars__t(C)_
++8.0 NoClash(C_F_4_1)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(45)__t(E)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(45)_disaggregatedVars__t(E)_
--92 NoClash(B_E_2_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(45)__t(F)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(45)_disaggregatedVars__t(F)_
+-92 NoClash(C_F_4_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(45)__t(B)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(45)_disaggregatedVars__t(B)_
--92 NoClash(B_E_2_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(45)__t(C)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(45)_disaggregatedVars__t(C)_
+-92 NoClash(C_F_4_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(46)_transformedConstraints(c_0_ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(46)_disaggregatedVars__t(D)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(46)_disaggregatedVars__t(B)_
-+10.0 NoClash(B_D_3_0)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(46)_disaggregatedVars__t(G)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(46)_disaggregatedVars__t(C)_
++2.0 NoClash(C_G_2_0)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(46)__t(D)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(46)_disaggregatedVars__t(D)_
--92 NoClash(B_D_3_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(46)__t(G)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(46)_disaggregatedVars__t(G)_
+-92 NoClash(C_G_2_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(46)__t(B)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(46)_disaggregatedVars__t(B)_
--92 NoClash(B_D_3_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(46)__t(C)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(46)_disaggregatedVars__t(C)_
+-92 NoClash(C_G_2_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(47)_transformedConstraints(c_0_ub)_:
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(47)_disaggregatedVars__t(D)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(47)_disaggregatedVars__t(B)_
--1 NoClash(B_D_3_1)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(47)_disaggregatedVars__t(G)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(47)_disaggregatedVars__t(C)_
++9.0 NoClash(C_G_2_1)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(47)__t(D)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(47)_disaggregatedVars__t(D)_
--92 NoClash(B_D_3_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(47)__t(G)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(47)_disaggregatedVars__t(G)_
+-92 NoClash(C_G_2_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(47)__t(B)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(47)_disaggregatedVars__t(B)_
--92 NoClash(B_D_3_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(47)__t(C)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(47)_disaggregatedVars__t(C)_
+-92 NoClash(C_G_2_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(48)_transformedConstraints(c_0_ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(48)_disaggregatedVars__t(D)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(48)_disaggregatedVars__t(B)_
-+8.0 NoClash(B_D_2_0)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(48)_disaggregatedVars__t(G)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(48)_disaggregatedVars__t(C)_
++4.0 NoClash(C_G_4_0)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(48)__t(D)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(48)_disaggregatedVars__t(D)_
--92 NoClash(B_D_2_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(48)__t(G)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(48)_disaggregatedVars__t(G)_
+-92 NoClash(C_G_4_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(48)__t(B)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(48)_disaggregatedVars__t(B)_
--92 NoClash(B_D_2_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(48)__t(C)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(48)_disaggregatedVars__t(C)_
+-92 NoClash(C_G_4_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(49)_transformedConstraints(c_0_ub)_:
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(49)_disaggregatedVars__t(D)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(49)_disaggregatedVars__t(B)_
-+3.0 NoClash(B_D_2_1)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(49)_disaggregatedVars__t(G)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(49)_disaggregatedVars__t(C)_
++7.0 NoClash(C_G_4_1)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(49)__t(D)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(49)_disaggregatedVars__t(D)_
--92 NoClash(B_D_2_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(49)__t(G)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(49)_disaggregatedVars__t(G)_
+-92 NoClash(C_G_4_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(49)__t(B)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(49)_disaggregatedVars__t(B)_
--92 NoClash(B_D_2_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(49)__t(C)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(49)_disaggregatedVars__t(C)_
+-92 NoClash(C_G_4_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(50)_transformedConstraints(c_0_ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(50)_disaggregatedVars__t(C)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(50)_disaggregatedVars__t(B)_
-+9.0 NoClash(B_C_2_0)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(50)_disaggregatedVars__t(E)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(50)_disaggregatedVars__t(D)_
++4.0 NoClash(D_E_2_0)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(50)__t(C)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(50)_disaggregatedVars__t(C)_
--92 NoClash(B_C_2_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(50)__t(E)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(50)_disaggregatedVars__t(E)_
+-92 NoClash(D_E_2_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(50)__t(B)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(50)_disaggregatedVars__t(B)_
--92 NoClash(B_C_2_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(50)__t(D)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(50)_disaggregatedVars__t(D)_
+-92 NoClash(D_E_2_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(51)_transformedConstraints(c_0_ub)_:
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(51)_disaggregatedVars__t(C)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(51)_disaggregatedVars__t(B)_
--3.0 NoClash(B_C_2_1)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(51)_disaggregatedVars__t(E)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(51)_disaggregatedVars__t(D)_
++8.0 NoClash(D_E_2_1)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(51)__t(C)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(51)_disaggregatedVars__t(C)_
--92 NoClash(B_C_2_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(51)__t(E)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(51)_disaggregatedVars__t(E)_
+-92 NoClash(D_E_2_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(51)__t(B)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(51)_disaggregatedVars__t(B)_
--92 NoClash(B_C_2_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(51)__t(D)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(51)_disaggregatedVars__t(D)_
+-92 NoClash(D_E_2_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(52)_transformedConstraints(c_0_ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(52)_disaggregatedVars__t(G)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(52)_disaggregatedVars__t(A)_
-+9.0 NoClash(A_G_5_0)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(52)_disaggregatedVars__t(E)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(52)_disaggregatedVars__t(D)_
++2.0 NoClash(D_E_3_0)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(52)__t(G)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(52)_disaggregatedVars__t(G)_
--92 NoClash(A_G_5_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(52)__t(E)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(52)_disaggregatedVars__t(E)_
+-92 NoClash(D_E_3_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(52)__t(A)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(52)_disaggregatedVars__t(A)_
--92 NoClash(A_G_5_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(52)__t(D)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(52)_disaggregatedVars__t(D)_
+-92 NoClash(D_E_3_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(53)_transformedConstraints(c_0_ub)_:
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(53)_disaggregatedVars__t(G)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(53)_disaggregatedVars__t(A)_
--3.0 NoClash(A_G_5_1)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(53)_disaggregatedVars__t(E)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(53)_disaggregatedVars__t(D)_
++9.0 NoClash(D_E_3_1)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(53)__t(G)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(53)_disaggregatedVars__t(G)_
--92 NoClash(A_G_5_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(53)__t(E)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(53)_disaggregatedVars__t(E)_
+-92 NoClash(D_E_3_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(53)__t(A)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(53)_disaggregatedVars__t(A)_
--92 NoClash(A_G_5_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(53)__t(D)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(53)_disaggregatedVars__t(D)_
+-92 NoClash(D_E_3_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(54)_transformedConstraints(c_0_ub)_:
 +1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(54)_disaggregatedVars__t(F)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(54)_disaggregatedVars__t(A)_
-+4.0 NoClash(A_F_3_0)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(54)_disaggregatedVars__t(D)_
+-1 NoClash(D_F_3_0)_binary_indicator_var
 <= 0.0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(54)__t(F)_bounds_(ub)_:
 +1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(54)_disaggregatedVars__t(F)_
--92 NoClash(A_F_3_0)_binary_indicator_var
+-92 NoClash(D_F_3_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(54)__t(A)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(54)_disaggregatedVars__t(A)_
--92 NoClash(A_F_3_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(54)__t(D)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(54)_disaggregatedVars__t(D)_
+-92 NoClash(D_F_3_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(55)_transformedConstraints(c_0_ub)_:
 -1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(55)_disaggregatedVars__t(F)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(55)_disaggregatedVars__t(A)_
-+6.0 NoClash(A_F_3_1)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(55)_disaggregatedVars__t(D)_
++11.0 NoClash(D_F_3_1)_binary_indicator_var
 <= 0.0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(55)__t(F)_bounds_(ub)_:
 +1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(55)_disaggregatedVars__t(F)_
--92 NoClash(A_F_3_1)_binary_indicator_var
+-92 NoClash(D_F_3_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(55)__t(A)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(55)_disaggregatedVars__t(A)_
--92 NoClash(A_F_3_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(55)__t(D)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(55)_disaggregatedVars__t(D)_
+-92 NoClash(D_F_3_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(56)_transformedConstraints(c_0_ub)_:
 +1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(56)_disaggregatedVars__t(F)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(56)_disaggregatedVars__t(A)_
-+2.0 NoClash(A_F_1_0)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(56)_disaggregatedVars__t(D)_
++1 NoClash(D_F_4_0)_binary_indicator_var
 <= 0.0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(56)__t(F)_bounds_(ub)_:
 +1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(56)_disaggregatedVars__t(F)_
--92 NoClash(A_F_1_0)_binary_indicator_var
+-92 NoClash(D_F_4_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(56)__t(A)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(56)_disaggregatedVars__t(A)_
--92 NoClash(A_F_1_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(56)__t(D)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(56)_disaggregatedVars__t(D)_
+-92 NoClash(D_F_4_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(57)_transformedConstraints(c_0_ub)_:
 -1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(57)_disaggregatedVars__t(F)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(57)_disaggregatedVars__t(A)_
-+3.0 NoClash(A_F_1_1)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(57)_disaggregatedVars__t(D)_
++7.0 NoClash(D_F_4_1)_binary_indicator_var
 <= 0.0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(57)__t(F)_bounds_(ub)_:
 +1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(57)_disaggregatedVars__t(F)_
--92 NoClash(A_F_1_1)_binary_indicator_var
+-92 NoClash(D_F_4_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(57)__t(A)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(57)_disaggregatedVars__t(A)_
--92 NoClash(A_F_1_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(57)__t(D)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(57)_disaggregatedVars__t(D)_
+-92 NoClash(D_F_4_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(58)_transformedConstraints(c_0_ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(58)_disaggregatedVars__t(E)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(58)_disaggregatedVars__t(A)_
-+4.0 NoClash(A_E_5_0)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(58)_disaggregatedVars__t(G)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(58)_disaggregatedVars__t(D)_
++8.0 NoClash(D_G_2_0)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(58)__t(E)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(58)_disaggregatedVars__t(E)_
--92 NoClash(A_E_5_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(58)__t(G)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(58)_disaggregatedVars__t(G)_
+-92 NoClash(D_G_2_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(58)__t(A)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(58)_disaggregatedVars__t(A)_
--92 NoClash(A_E_5_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(58)__t(D)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(58)_disaggregatedVars__t(D)_
+-92 NoClash(D_G_2_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(59)_transformedConstraints(c_0_ub)_:
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(59)_disaggregatedVars__t(E)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(59)_disaggregatedVars__t(A)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(59)_disaggregatedVars__t(G)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(59)_disaggregatedVars__t(D)_
++8.0 NoClash(D_G_2_1)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(59)__t(E)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(59)_disaggregatedVars__t(E)_
--92 NoClash(A_E_5_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(59)__t(G)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(59)_disaggregatedVars__t(G)_
+-92 NoClash(D_G_2_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(59)__t(A)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(59)_disaggregatedVars__t(A)_
--92 NoClash(A_E_5_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(59)__t(D)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(59)_disaggregatedVars__t(D)_
+-92 NoClash(D_G_2_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(60)_transformedConstraints(c_0_ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(60)_disaggregatedVars__t(E)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(60)_disaggregatedVars__t(A)_
-+7.0 NoClash(A_E_3_0)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(60)_disaggregatedVars__t(G)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(60)_disaggregatedVars__t(D)_
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(60)__t(E)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(60)_disaggregatedVars__t(E)_
--92 NoClash(A_E_3_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(60)__t(G)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(60)_disaggregatedVars__t(G)_
+-92 NoClash(D_G_4_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(60)__t(A)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(60)_disaggregatedVars__t(A)_
--92 NoClash(A_E_3_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(60)__t(D)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(60)_disaggregatedVars__t(D)_
+-92 NoClash(D_G_4_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(61)_transformedConstraints(c_0_ub)_:
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(61)_disaggregatedVars__t(E)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(61)_disaggregatedVars__t(A)_
-+4.0 NoClash(A_E_3_1)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(61)_disaggregatedVars__t(G)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(61)_disaggregatedVars__t(D)_
++6.0 NoClash(D_G_4_1)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(61)__t(E)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(61)_disaggregatedVars__t(E)_
--92 NoClash(A_E_3_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(61)__t(G)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(61)_disaggregatedVars__t(G)_
+-92 NoClash(D_G_4_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(61)__t(A)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(61)_disaggregatedVars__t(A)_
--92 NoClash(A_E_3_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(61)__t(D)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(61)_disaggregatedVars__t(D)_
+-92 NoClash(D_G_4_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(62)_transformedConstraints(c_0_ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(62)_disaggregatedVars__t(D)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(62)_disaggregatedVars__t(A)_
-+10.0 NoClash(A_D_3_0)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(62)_disaggregatedVars__t(F)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(62)_disaggregatedVars__t(E)_
++3.0 NoClash(E_F_3_0)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(62)__t(D)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(62)_disaggregatedVars__t(D)_
--92 NoClash(A_D_3_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(62)__t(F)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(62)_disaggregatedVars__t(F)_
+-92 NoClash(E_F_3_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(62)__t(A)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(62)_disaggregatedVars__t(A)_
--92 NoClash(A_D_3_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(62)__t(E)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(62)_disaggregatedVars__t(E)_
+-92 NoClash(E_F_3_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(63)_transformedConstraints(c_0_ub)_:
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(63)_disaggregatedVars__t(D)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(63)_disaggregatedVars__t(A)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(63)_disaggregatedVars__t(F)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(63)_disaggregatedVars__t(E)_
++8.0 NoClash(E_F_3_1)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(63)__t(D)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(63)_disaggregatedVars__t(D)_
--92 NoClash(A_D_3_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(63)__t(F)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(63)_disaggregatedVars__t(F)_
+-92 NoClash(E_F_3_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(63)__t(A)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(63)_disaggregatedVars__t(A)_
--92 NoClash(A_D_3_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(63)__t(E)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(63)_disaggregatedVars__t(E)_
+-92 NoClash(E_F_3_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(64)_transformedConstraints(c_0_ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(64)_disaggregatedVars__t(C)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(64)_disaggregatedVars__t(A)_
-+6.0 NoClash(A_C_1_0)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(64)_disaggregatedVars__t(G)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(64)_disaggregatedVars__t(E)_
++8.0 NoClash(E_G_2_0)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(64)__t(C)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(64)_disaggregatedVars__t(C)_
--92 NoClash(A_C_1_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(64)__t(G)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(64)_disaggregatedVars__t(G)_
+-92 NoClash(E_G_2_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(64)__t(A)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(64)_disaggregatedVars__t(A)_
--92 NoClash(A_C_1_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(64)__t(E)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(64)_disaggregatedVars__t(E)_
+-92 NoClash(E_G_2_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(65)_transformedConstraints(c_0_ub)_:
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(65)_disaggregatedVars__t(C)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(65)_disaggregatedVars__t(A)_
-+3.0 NoClash(A_C_1_1)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(65)_disaggregatedVars__t(G)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(65)_disaggregatedVars__t(E)_
++4.0 NoClash(E_G_2_1)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(65)__t(C)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(65)_disaggregatedVars__t(C)_
--92 NoClash(A_C_1_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(65)__t(G)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(65)_disaggregatedVars__t(G)_
+-92 NoClash(E_G_2_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(65)__t(A)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(65)_disaggregatedVars__t(A)_
--92 NoClash(A_C_1_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(65)__t(E)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(65)_disaggregatedVars__t(E)_
+-92 NoClash(E_G_2_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(66)_transformedConstraints(c_0_ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(66)_disaggregatedVars__t(B)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(66)_disaggregatedVars__t(A)_
-+2.0 NoClash(A_B_5_0)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(66)_disaggregatedVars__t(G)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(66)_disaggregatedVars__t(E)_
++7.0 NoClash(E_G_5_0)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(66)__t(B)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(66)_disaggregatedVars__t(B)_
--92 NoClash(A_B_5_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(66)__t(G)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(66)_disaggregatedVars__t(G)_
+-92 NoClash(E_G_5_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(66)__t(A)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(66)_disaggregatedVars__t(A)_
--92 NoClash(A_B_5_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(66)__t(E)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(66)_disaggregatedVars__t(E)_
+-92 NoClash(E_G_5_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(67)_transformedConstraints(c_0_ub)_:
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(67)_disaggregatedVars__t(B)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(67)_disaggregatedVars__t(A)_
-+3.0 NoClash(A_B_5_1)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(67)_disaggregatedVars__t(G)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(67)_disaggregatedVars__t(E)_
+-1 NoClash(E_G_5_1)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(67)__t(B)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(67)_disaggregatedVars__t(B)_
--92 NoClash(A_B_5_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(67)__t(G)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(67)_disaggregatedVars__t(G)_
+-92 NoClash(E_G_5_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(67)__t(A)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(67)_disaggregatedVars__t(A)_
--92 NoClash(A_B_5_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(67)__t(E)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(67)_disaggregatedVars__t(E)_
+-92 NoClash(E_G_5_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(68)_transformedConstraints(c_0_ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(68)_disaggregatedVars__t(B)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(68)_disaggregatedVars__t(A)_
-+4.0 NoClash(A_B_3_0)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(68)_disaggregatedVars__t(G)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(68)_disaggregatedVars__t(F)_
++6.0 NoClash(F_G_4_0)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(68)__t(B)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(68)_disaggregatedVars__t(B)_
--92 NoClash(A_B_3_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(68)__t(G)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(68)_disaggregatedVars__t(G)_
+-92 NoClash(F_G_4_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(68)__t(A)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(68)_disaggregatedVars__t(A)_
--92 NoClash(A_B_3_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(68)__t(F)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(68)_disaggregatedVars__t(F)_
+-92 NoClash(F_G_4_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(69)_transformedConstraints(c_0_ub)_:
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(69)_disaggregatedVars__t(B)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(69)_disaggregatedVars__t(A)_
-+5.0 NoClash(A_B_3_1)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(69)_disaggregatedVars__t(G)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(69)_disaggregatedVars__t(F)_
++6.0 NoClash(F_G_4_1)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(69)__t(B)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(69)_disaggregatedVars__t(B)_
--92 NoClash(A_B_3_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(69)__t(G)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(69)_disaggregatedVars__t(G)_
+-92 NoClash(F_G_4_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(69)__t(A)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(69)_disaggregatedVars__t(A)_
--92 NoClash(A_B_3_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(69)__t(F)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(69)_disaggregatedVars__t(F)_
+-92 NoClash(F_G_4_1)_binary_indicator_var
 <= 0
 
 bounds
@@ -1761,146 +1761,146 @@ bounds
    0 <= t(E) <= 92
    0 <= t(F) <= 92
    0 <= t(G) <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_disaggregatedVars__t(G)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_disaggregatedVars__t(G)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_disaggregatedVars__t(F)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_disaggregatedVars__t(F)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(2)_disaggregatedVars__t(G)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(3)_disaggregatedVars__t(G)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(2)_disaggregatedVars__t(E)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(3)_disaggregatedVars__t(E)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(G)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(G)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(E)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(E)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(6)_disaggregatedVars__t(F)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(7)_disaggregatedVars__t(F)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(6)_disaggregatedVars__t(E)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(7)_disaggregatedVars__t(E)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(8)_disaggregatedVars__t(G)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(9)_disaggregatedVars__t(G)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(8)_disaggregatedVars__t(D)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(9)_disaggregatedVars__t(D)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(10)_disaggregatedVars__t(G)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(11)_disaggregatedVars__t(G)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(10)_disaggregatedVars__t(D)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(11)_disaggregatedVars__t(D)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_disaggregatedVars__t(B)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_disaggregatedVars__t(B)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_disaggregatedVars__t(A)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_disaggregatedVars__t(A)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(2)_disaggregatedVars__t(B)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(3)_disaggregatedVars__t(B)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(2)_disaggregatedVars__t(A)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(3)_disaggregatedVars__t(A)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(C)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(C)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(A)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(A)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(6)_disaggregatedVars__t(D)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(7)_disaggregatedVars__t(D)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(6)_disaggregatedVars__t(A)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(7)_disaggregatedVars__t(A)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(8)_disaggregatedVars__t(E)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(9)_disaggregatedVars__t(E)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(8)_disaggregatedVars__t(A)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(9)_disaggregatedVars__t(A)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(10)_disaggregatedVars__t(E)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(11)_disaggregatedVars__t(E)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(10)_disaggregatedVars__t(A)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(11)_disaggregatedVars__t(A)_ <= 92
    0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(12)_disaggregatedVars__t(F)_ <= 92
    0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(13)_disaggregatedVars__t(F)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(12)_disaggregatedVars__t(D)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(13)_disaggregatedVars__t(D)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(12)_disaggregatedVars__t(A)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(13)_disaggregatedVars__t(A)_ <= 92
    0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(14)_disaggregatedVars__t(F)_ <= 92
    0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(15)_disaggregatedVars__t(F)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(14)_disaggregatedVars__t(D)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(15)_disaggregatedVars__t(D)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(16)_disaggregatedVars__t(E)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(17)_disaggregatedVars__t(E)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(16)_disaggregatedVars__t(D)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(17)_disaggregatedVars__t(D)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(18)_disaggregatedVars__t(E)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(19)_disaggregatedVars__t(E)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(18)_disaggregatedVars__t(D)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(19)_disaggregatedVars__t(D)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(20)_disaggregatedVars__t(G)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(21)_disaggregatedVars__t(G)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(20)_disaggregatedVars__t(C)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(21)_disaggregatedVars__t(C)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(22)_disaggregatedVars__t(G)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(23)_disaggregatedVars__t(G)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(22)_disaggregatedVars__t(C)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(23)_disaggregatedVars__t(C)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(24)_disaggregatedVars__t(F)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(25)_disaggregatedVars__t(F)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(24)_disaggregatedVars__t(C)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(25)_disaggregatedVars__t(C)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(26)_disaggregatedVars__t(F)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(27)_disaggregatedVars__t(F)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(26)_disaggregatedVars__t(C)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(27)_disaggregatedVars__t(C)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(14)_disaggregatedVars__t(A)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(15)_disaggregatedVars__t(A)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(16)_disaggregatedVars__t(G)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(17)_disaggregatedVars__t(G)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(16)_disaggregatedVars__t(A)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(17)_disaggregatedVars__t(A)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(18)_disaggregatedVars__t(C)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(19)_disaggregatedVars__t(C)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(18)_disaggregatedVars__t(B)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(19)_disaggregatedVars__t(B)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(20)_disaggregatedVars__t(D)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(21)_disaggregatedVars__t(D)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(20)_disaggregatedVars__t(B)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(21)_disaggregatedVars__t(B)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(22)_disaggregatedVars__t(D)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(23)_disaggregatedVars__t(D)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(22)_disaggregatedVars__t(B)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(23)_disaggregatedVars__t(B)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(24)_disaggregatedVars__t(E)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(25)_disaggregatedVars__t(E)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(24)_disaggregatedVars__t(B)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(25)_disaggregatedVars__t(B)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(26)_disaggregatedVars__t(E)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(27)_disaggregatedVars__t(E)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(26)_disaggregatedVars__t(B)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(27)_disaggregatedVars__t(B)_ <= 92
    0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(28)_disaggregatedVars__t(E)_ <= 92
    0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(29)_disaggregatedVars__t(E)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(28)_disaggregatedVars__t(C)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(29)_disaggregatedVars__t(C)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(30)_disaggregatedVars__t(D)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(31)_disaggregatedVars__t(D)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(30)_disaggregatedVars__t(C)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(31)_disaggregatedVars__t(C)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(32)_disaggregatedVars__t(D)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(33)_disaggregatedVars__t(D)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(32)_disaggregatedVars__t(C)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(33)_disaggregatedVars__t(C)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(28)_disaggregatedVars__t(B)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(29)_disaggregatedVars__t(B)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(30)_disaggregatedVars__t(F)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(31)_disaggregatedVars__t(F)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(30)_disaggregatedVars__t(B)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(31)_disaggregatedVars__t(B)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(32)_disaggregatedVars__t(G)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(33)_disaggregatedVars__t(G)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(32)_disaggregatedVars__t(B)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(33)_disaggregatedVars__t(B)_ <= 92
    0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(34)_disaggregatedVars__t(G)_ <= 92
    0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(35)_disaggregatedVars__t(G)_ <= 92
    0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(34)_disaggregatedVars__t(B)_ <= 92
    0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(35)_disaggregatedVars__t(B)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(36)_disaggregatedVars__t(G)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(37)_disaggregatedVars__t(G)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(36)_disaggregatedVars__t(B)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(37)_disaggregatedVars__t(B)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(38)_disaggregatedVars__t(F)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(39)_disaggregatedVars__t(F)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(38)_disaggregatedVars__t(B)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(39)_disaggregatedVars__t(B)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(36)_disaggregatedVars__t(D)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(37)_disaggregatedVars__t(D)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(36)_disaggregatedVars__t(C)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(37)_disaggregatedVars__t(C)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(38)_disaggregatedVars__t(D)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(39)_disaggregatedVars__t(D)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(38)_disaggregatedVars__t(C)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(39)_disaggregatedVars__t(C)_ <= 92
    0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(40)_disaggregatedVars__t(E)_ <= 92
    0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(41)_disaggregatedVars__t(E)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(40)_disaggregatedVars__t(B)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(41)_disaggregatedVars__t(B)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(42)_disaggregatedVars__t(E)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(43)_disaggregatedVars__t(E)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(42)_disaggregatedVars__t(B)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(43)_disaggregatedVars__t(B)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(44)_disaggregatedVars__t(E)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(45)_disaggregatedVars__t(E)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(44)_disaggregatedVars__t(B)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(45)_disaggregatedVars__t(B)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(46)_disaggregatedVars__t(D)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(47)_disaggregatedVars__t(D)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(46)_disaggregatedVars__t(B)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(47)_disaggregatedVars__t(B)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(48)_disaggregatedVars__t(D)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(49)_disaggregatedVars__t(D)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(48)_disaggregatedVars__t(B)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(49)_disaggregatedVars__t(B)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(50)_disaggregatedVars__t(C)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(51)_disaggregatedVars__t(C)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(50)_disaggregatedVars__t(B)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(51)_disaggregatedVars__t(B)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(52)_disaggregatedVars__t(G)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(53)_disaggregatedVars__t(G)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(52)_disaggregatedVars__t(A)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(53)_disaggregatedVars__t(A)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(40)_disaggregatedVars__t(C)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(41)_disaggregatedVars__t(C)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(42)_disaggregatedVars__t(F)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(43)_disaggregatedVars__t(F)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(42)_disaggregatedVars__t(C)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(43)_disaggregatedVars__t(C)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(44)_disaggregatedVars__t(F)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(45)_disaggregatedVars__t(F)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(44)_disaggregatedVars__t(C)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(45)_disaggregatedVars__t(C)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(46)_disaggregatedVars__t(G)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(47)_disaggregatedVars__t(G)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(46)_disaggregatedVars__t(C)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(47)_disaggregatedVars__t(C)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(48)_disaggregatedVars__t(G)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(49)_disaggregatedVars__t(G)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(48)_disaggregatedVars__t(C)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(49)_disaggregatedVars__t(C)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(50)_disaggregatedVars__t(E)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(51)_disaggregatedVars__t(E)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(50)_disaggregatedVars__t(D)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(51)_disaggregatedVars__t(D)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(52)_disaggregatedVars__t(E)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(53)_disaggregatedVars__t(E)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(52)_disaggregatedVars__t(D)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(53)_disaggregatedVars__t(D)_ <= 92
    0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(54)_disaggregatedVars__t(F)_ <= 92
    0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(55)_disaggregatedVars__t(F)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(54)_disaggregatedVars__t(A)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(55)_disaggregatedVars__t(A)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(54)_disaggregatedVars__t(D)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(55)_disaggregatedVars__t(D)_ <= 92
    0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(56)_disaggregatedVars__t(F)_ <= 92
    0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(57)_disaggregatedVars__t(F)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(56)_disaggregatedVars__t(A)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(57)_disaggregatedVars__t(A)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(58)_disaggregatedVars__t(E)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(59)_disaggregatedVars__t(E)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(58)_disaggregatedVars__t(A)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(59)_disaggregatedVars__t(A)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(60)_disaggregatedVars__t(E)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(61)_disaggregatedVars__t(E)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(60)_disaggregatedVars__t(A)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(61)_disaggregatedVars__t(A)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(62)_disaggregatedVars__t(D)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(63)_disaggregatedVars__t(D)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(62)_disaggregatedVars__t(A)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(63)_disaggregatedVars__t(A)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(64)_disaggregatedVars__t(C)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(65)_disaggregatedVars__t(C)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(64)_disaggregatedVars__t(A)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(65)_disaggregatedVars__t(A)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(66)_disaggregatedVars__t(B)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(67)_disaggregatedVars__t(B)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(66)_disaggregatedVars__t(A)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(67)_disaggregatedVars__t(A)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(68)_disaggregatedVars__t(B)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(69)_disaggregatedVars__t(B)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(68)_disaggregatedVars__t(A)_ <= 92
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(69)_disaggregatedVars__t(A)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(56)_disaggregatedVars__t(D)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(57)_disaggregatedVars__t(D)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(58)_disaggregatedVars__t(G)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(59)_disaggregatedVars__t(G)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(58)_disaggregatedVars__t(D)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(59)_disaggregatedVars__t(D)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(60)_disaggregatedVars__t(G)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(61)_disaggregatedVars__t(G)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(60)_disaggregatedVars__t(D)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(61)_disaggregatedVars__t(D)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(62)_disaggregatedVars__t(F)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(63)_disaggregatedVars__t(F)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(62)_disaggregatedVars__t(E)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(63)_disaggregatedVars__t(E)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(64)_disaggregatedVars__t(G)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(65)_disaggregatedVars__t(G)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(64)_disaggregatedVars__t(E)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(65)_disaggregatedVars__t(E)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(66)_disaggregatedVars__t(G)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(67)_disaggregatedVars__t(G)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(66)_disaggregatedVars__t(E)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(67)_disaggregatedVars__t(E)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(68)_disaggregatedVars__t(G)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(69)_disaggregatedVars__t(G)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(68)_disaggregatedVars__t(F)_ <= 92
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(69)_disaggregatedVars__t(F)_ <= 92
    0 <= NoClash(A_B_3_0)_binary_indicator_var <= 1
    0 <= NoClash(A_B_3_1)_binary_indicator_var <= 1
    0 <= NoClash(A_B_5_0)_binary_indicator_var <= 1
diff --git a/pyomo/gdp/tests/jobshop_small_hull.lp b/pyomo/gdp/tests/jobshop_small_hull.lp
index c07b9cd048e..eccaa800600 100644
--- a/pyomo/gdp/tests/jobshop_small_hull.lp
+++ b/pyomo/gdp/tests/jobshop_small_hull.lp
@@ -22,17 +22,17 @@ c_u_Feas(C)_:
 <= -6
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(0)_:
-+1 t(C)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_disaggregatedVars__t(C)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_disaggregatedVars__t(C)_
-= 0
-
-c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(1)_:
 +1 t(B)
 -1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_disaggregatedVars__t(B)_
 -1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_disaggregatedVars__t(B)_
 = 0
 
+c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(1)_:
++1 t(A)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_disaggregatedVars__t(A)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_disaggregatedVars__t(A)_
+= 0
+
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(2)_:
 +1 t(C)
 -1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(2)_disaggregatedVars__t(C)_
@@ -46,15 +46,15 @@ c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(3)_:
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(4)_:
-+1 t(B)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(B)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(B)_
++1 t(C)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(C)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(C)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disaggregationConstraints(5)_:
-+1 t(A)
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(A)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(A)_
++1 t(B)
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(B)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(B)_
 = 0
 
 c_e__pyomo_gdp_hull_reformulation_disj_xor(A_B_3)_:
@@ -73,35 +73,34 @@ c_e__pyomo_gdp_hull_reformulation_disj_xor(B_C_2)_:
 = 1
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_transformedConstraints(c_0_ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_disaggregatedVars__t(C)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_disaggregatedVars__t(B)_
-+6.0 NoClash(B_C_2_0)_binary_indicator_var
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_disaggregatedVars__t(B)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_disaggregatedVars__t(A)_
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)__t(C)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_disaggregatedVars__t(C)_
--19 NoClash(B_C_2_0)_binary_indicator_var
-<= 0
-
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)__t(B)_bounds_(ub)_:
 +1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_disaggregatedVars__t(B)_
--19 NoClash(B_C_2_0)_binary_indicator_var
+-19 NoClash(A_B_3_0)_binary_indicator_var
+<= 0
+
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)__t(A)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_disaggregatedVars__t(A)_
+-19 NoClash(A_B_3_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_transformedConstraints(c_0_ub)_:
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_disaggregatedVars__t(C)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_disaggregatedVars__t(B)_
-+1 NoClash(B_C_2_1)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_disaggregatedVars__t(B)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_disaggregatedVars__t(A)_
++5.0 NoClash(A_B_3_1)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)__t(C)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_disaggregatedVars__t(C)_
--19 NoClash(B_C_2_1)_binary_indicator_var
-<= 0
-
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)__t(B)_bounds_(ub)_:
 +1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_disaggregatedVars__t(B)_
--19 NoClash(B_C_2_1)_binary_indicator_var
+-19 NoClash(A_B_3_1)_binary_indicator_var
+<= 0
+
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)__t(A)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_disaggregatedVars__t(A)_
+-19 NoClash(A_B_3_1)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(2)_transformedConstraints(c_0_ub)_:
@@ -137,34 +136,35 @@ c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(3)__t(A)_bounds_(ub)_:
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_transformedConstraints(c_0_ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(B)_
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(A)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(C)_
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(B)_
++6.0 NoClash(B_C_2_0)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)__t(B)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(B)_
--19 NoClash(A_B_3_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)__t(C)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(C)_
+-19 NoClash(B_C_2_0)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)__t(A)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(A)_
--19 NoClash(A_B_3_0)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)__t(B)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(B)_
+-19 NoClash(B_C_2_0)_binary_indicator_var
 <= 0
 
 c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_transformedConstraints(c_0_ub)_:
--1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(B)_
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(A)_
-+5.0 NoClash(A_B_3_1)_binary_indicator_var
+-1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(C)_
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(B)_
++1 NoClash(B_C_2_1)_binary_indicator_var
 <= 0.0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)__t(B)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(B)_
--19 NoClash(A_B_3_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)__t(C)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(C)_
+-19 NoClash(B_C_2_1)_binary_indicator_var
 <= 0
 
-c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)__t(A)_bounds_(ub)_:
-+1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(A)_
--19 NoClash(A_B_3_1)_binary_indicator_var
+c_u__pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)__t(B)_bounds_(ub)_:
++1 _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(B)_
+-19 NoClash(B_C_2_1)_binary_indicator_var
 <= 0
 
 bounds
@@ -172,18 +172,18 @@ bounds
    0 <= t(A) <= 19
    0 <= t(B) <= 19
    0 <= t(C) <= 19
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_disaggregatedVars__t(C)_ <= 19
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_disaggregatedVars__t(C)_ <= 19
    0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_disaggregatedVars__t(B)_ <= 19
    0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_disaggregatedVars__t(B)_ <= 19
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(0)_disaggregatedVars__t(A)_ <= 19
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(1)_disaggregatedVars__t(A)_ <= 19
    0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(2)_disaggregatedVars__t(C)_ <= 19
    0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(3)_disaggregatedVars__t(C)_ <= 19
    0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(2)_disaggregatedVars__t(A)_ <= 19
    0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(3)_disaggregatedVars__t(A)_ <= 19
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(C)_ <= 19
+   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(C)_ <= 19
    0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(B)_ <= 19
    0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(B)_ <= 19
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(4)_disaggregatedVars__t(A)_ <= 19
-   0 <= _pyomo_gdp_hull_reformulation_relaxedDisjuncts(5)_disaggregatedVars__t(A)_ <= 19
    0 <= NoClash(A_B_3_0)_binary_indicator_var <= 1
    0 <= NoClash(A_B_3_1)_binary_indicator_var <= 1
    0 <= NoClash(A_C_1_0)_binary_indicator_var <= 1
diff --git a/pyomo/gdp/tests/models.py b/pyomo/gdp/tests/models.py
index a52f08b790e..2995cacb450 100644
--- a/pyomo/gdp/tests/models.py
+++ b/pyomo/gdp/tests/models.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.core import (
     Block,
     ConcreteModel,
@@ -463,7 +474,7 @@ def makeNestedDisjunctions():
 
     (makeNestedDisjunctions_NestedDisjuncts is a much simpler model. All
     this adds is that it has a nested disjunction on a DisjunctData as well
-    as on a SimpleDisjunct. So mostly it exists for historical reasons.)
+    as on a ScalarDisjunct. So mostly it exists for historical reasons.)
     """
     m = ConcreteModel()
     m.x = Var(bounds=(-9, 9))
@@ -552,6 +563,44 @@ def makeNestedDisjunctions_NestedDisjuncts():
     return m
 
 
+def why_indicator_vars_are_not_always_local():
+    m = ConcreteModel()
+    m.x = Var(bounds=(1, 10))
+
+    @m.Disjunct()
+    def Z1(d):
+        m = d.model()
+        d.c = Constraint(expr=m.x >= 1.1)
+
+    @m.Disjunct()
+    def Z2(d):
+        m = d.model()
+        d.c = Constraint(expr=m.x >= 1.2)
+
+    @m.Disjunct()
+    def Y1(d):
+        m = d.model()
+        d.c = Constraint(expr=(1.15, m.x, 8))
+        d.disjunction = Disjunction(expr=[m.Z1, m.Z2])
+
+    @m.Disjunct()
+    def Y2(d):
+        m = d.model()
+        d.c = Constraint(expr=m.x == 9)
+
+    m.disjunction = Disjunction(expr=[m.Y1, m.Y2])
+
+    m.logical_cons = LogicalConstraint(
+        expr=m.Y2.indicator_var.implies(m.Z1.indicator_var.land(m.Z2.indicator_var))
+    )
+
+    # optimal value is 9, but it will be 8 if we wrongly assume that the nested
+    # indicator_vars are local.
+    m.obj = Objective(expr=m.x, sense=maximize)
+
+    return m
+
+
 def makeTwoSimpleDisjunctions():
     """Two SimpleDisjunctions on the same model."""
     m = ConcreteModel()
@@ -791,7 +840,7 @@ def makeAnyIndexedDisjunctionOfDisjunctDatas():
     build from DisjunctDatas. Identical mathematically to
     makeDisjunctionOfDisjunctDatas.
 
-    Used to test that the right things happen for a case where soemone
+    Used to test that the right things happen for a case where someone
     implements an algorithm which iteratively generates disjuncts and
     retransforms"""
     m = ConcreteModel()
diff --git a/pyomo/gdp/tests/test_basic_step.py b/pyomo/gdp/tests/test_basic_step.py
index 631611a2651..7e21c46da92 100644
--- a/pyomo/gdp/tests/test_basic_step.py
+++ b/pyomo/gdp/tests/test_basic_step.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/gdp/tests/test_bigm.py b/pyomo/gdp/tests/test_bigm.py
index 13ffe30f9f0..c27d7cbe0cb 100644
--- a/pyomo/gdp/tests/test_bigm.py
+++ b/pyomo/gdp/tests/test_bigm.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -19,20 +19,24 @@
     Set,
     Constraint,
     ComponentMap,
+    LogicalConstraint,
+    Objective,
     SolverFactory,
     Suffix,
+    TerminationCondition,
     ConcreteModel,
     Var,
     Any,
     value,
 )
 from pyomo.gdp import Disjunct, Disjunction, GDP_Error
-from pyomo.core.base import constraint, _ConstraintData
+from pyomo.core.base import constraint, ConstraintData
 from pyomo.core.expr.compare import (
     assertExpressionsEqual,
     assertExpressionsStructurallyEqual,
 )
 from pyomo.repn import generate_standard_repn
+from pyomo.repn.linear import LinearRepnVisitor
 from pyomo.common.log import LoggingIntercept
 import logging
 
@@ -154,10 +158,7 @@ def test_or_constraints(self):
             self,
             orcons.body,
             EXPR.LinearExpression(
-                [
-                    EXPR.MonomialTermExpression((1, m.d[0].binary_indicator_var)),
-                    EXPR.MonomialTermExpression((1, m.d[1].binary_indicator_var)),
-                ]
+                [m.d[0].binary_indicator_var, m.d[1].binary_indicator_var]
             ),
         )
         self.assertEqual(orcons.lower, 1)
@@ -655,14 +656,14 @@ def test_disjunct_and_constraint_maps(self):
             if src[0]:
                 # equality
                 self.assertEqual(len(transformed), 2)
-                self.assertIsInstance(transformed[0], _ConstraintData)
-                self.assertIsInstance(transformed[1], _ConstraintData)
+                self.assertIsInstance(transformed[0], ConstraintData)
+                self.assertIsInstance(transformed[1], ConstraintData)
                 self.assertIs(bigm.get_src_constraint(transformed[0]), srcDisjunct.c)
                 self.assertIs(bigm.get_src_constraint(transformed[1]), srcDisjunct.c)
             else:
                 # >=
                 self.assertEqual(len(transformed), 1)
-                self.assertIsInstance(transformed[0], _ConstraintData)
+                self.assertIsInstance(transformed[0], ConstraintData)
                 # check reverse map from the container
                 self.assertIs(bigm.get_src_constraint(transformed[0]), srcDisjunct.c)
 
@@ -1315,26 +1316,18 @@ def test_do_not_transform_deactivated_constraintDatas(self):
         bigm.apply_to(m)
 
         # the real test: This wasn't transformed
-        log = StringIO()
-        with LoggingIntercept(log, 'pyomo.gdp', logging.ERROR):
-            self.assertRaisesRegex(
-                KeyError,
-                r".*b.simpledisj1.c\[1\]",
-                bigm.get_transformed_constraints,
-                m.b.simpledisj1.c[1],
-            )
-        self.assertRegex(
-            log.getvalue(),
-            r".*Constraint 'b.simpledisj1.c\[1\]' has not been transformed.",
-        )
+        with self.assertRaisesRegex(
+            GDP_Error, r"Constraint 'b.simpledisj1.c\[1\]' has not been transformed."
+        ):
+            bigm.get_transformed_constraints(m.b.simpledisj1.c[1])
 
         # and the rest of the container was transformed
         cons_list = bigm.get_transformed_constraints(m.b.simpledisj1.c[2])
         self.assertEqual(len(cons_list), 2)
         lb = cons_list[0]
         ub = cons_list[1]
-        self.assertIsInstance(lb, constraint._GeneralConstraintData)
-        self.assertIsInstance(ub, constraint._GeneralConstraintData)
+        self.assertIsInstance(lb, constraint.ConstraintData)
+        self.assertIsInstance(ub, constraint.ConstraintData)
 
     def checkMs(
         self, m, disj1c1lb, disj1c1ub, disj1c2lb, disj1c2ub, disj2c1ub, disj2c2ub
@@ -1764,22 +1757,19 @@ def test_transformation_block_structure(self):
         # we have the XOR constraints for both the outer and inner disjunctions
         self.assertIsInstance(transBlock.component("disjunction_xor"), Constraint)
 
-    def test_transformation_block_on_inner_disjunct_empty(self):
-        m = models.makeNestedDisjunctions()
-        TransformationFactory('gdp.bigm').apply_to(m)
-        self.assertIsNone(m.disjunct[1].component("_pyomo_gdp_bigm_reformulation"))
-
     def test_mappings_between_disjunctions_and_xors(self):
         m = models.makeNestedDisjunctions()
         transform = TransformationFactory('gdp.bigm')
         transform.apply_to(m)
 
         transBlock1 = m.component("_pyomo_gdp_bigm_reformulation")
+        transBlock2 = m.disjunct[1].component("_pyomo_gdp_bigm_reformulation")
+        transBlock3 = m.simpledisjunct.component("_pyomo_gdp_bigm_reformulation")
 
         disjunctionPairs = [
             (m.disjunction, transBlock1.disjunction_xor),
-            (m.disjunct[1].innerdisjunction[0], transBlock1.innerdisjunction_xor_4[0]),
-            (m.simpledisjunct.innerdisjunction, transBlock1.innerdisjunction_xor),
+            (m.disjunct[1].innerdisjunction[0], transBlock2.innerdisjunction_xor[0]),
+            (m.simpledisjunct.innerdisjunction, transBlock3.innerdisjunction_xor),
         ]
 
         # check disjunction mappings
@@ -1892,26 +1882,38 @@ def test_m_value_mappings(self):
     # many of the transformed constraints look like this, so can call this
     # function to test them.
     def check_bigM_constraint(self, cons, variable, M, indicator_var):
-        repn = generate_standard_repn(cons.body)
-        self.assertTrue(repn.is_linear())
-        self.assertEqual(repn.constant, -M)
-        self.assertEqual(len(repn.linear_vars), 2)
-        ct.check_linear_coef(self, repn, variable, 1)
-        ct.check_linear_coef(self, repn, indicator_var, M)
+        assertExpressionsEqual(
+            self,
+            cons.body,
+            variable - float(M) * (1 - indicator_var.get_associated_binary()),
+        )
 
-    def check_inner_xor_constraint(
-        self, inner_disjunction, outer_disjunct, inner_disjuncts
-    ):
-        self.assertIsNotNone(inner_disjunction.algebraic_constraint)
-        cons = inner_disjunction.algebraic_constraint
-        self.assertEqual(cons.lower, 0)
-        self.assertEqual(cons.upper, 0)
-        repn = generate_standard_repn(cons.body)
-        self.assertTrue(repn.is_linear())
-        self.assertEqual(repn.constant, 0)
-        for disj in inner_disjuncts:
-            ct.check_linear_coef(self, repn, disj.binary_indicator_var, 1)
-        ct.check_linear_coef(self, repn, outer_disjunct.binary_indicator_var, -1)
+    def check_inner_xor_constraint(self, inner_disjunction, outer_disjunct, bigm):
+        inner_xor = inner_disjunction.algebraic_constraint
+        sum_indicators = sum(
+            d.binary_indicator_var for d in inner_disjunction.disjuncts
+        )
+        assertExpressionsEqual(self, inner_xor.expr, sum_indicators == 1)
+        # this guy has been transformed
+        self.assertFalse(inner_xor.active)
+        cons = bigm.get_transformed_constraints(inner_xor)
+        self.assertEqual(len(cons), 2)
+        lb = cons[0]
+        ct.check_obj_in_active_tree(self, lb)
+        lb_expr = self.simplify_cons(lb, leq=False)
+        assertExpressionsEqual(
+            self,
+            lb_expr,
+            1.0 <= sum_indicators - outer_disjunct.binary_indicator_var + 1.0,
+        )
+        ub = cons[1]
+        ct.check_obj_in_active_tree(self, ub)
+        ub_expr = self.simplify_cons(ub, leq=True)
+        assertExpressionsEqual(
+            self,
+            ub_expr,
+            sum_indicators + outer_disjunct.binary_indicator_var - 1 <= 1.0,
+        )
 
     def test_transformed_constraints(self):
         # We'll check all the transformed constraints to make sure
@@ -1949,6 +1951,10 @@ def test_transformed_constraints(self):
                                                     .binary_indicator_var,
                                                 )
                                             ),
+                                            1,
+                                            EXPR.MonomialTermExpression(
+                                                (-1, m.disjunct[1].binary_indicator_var)
+                                            ),
                                         ]
                                     ),
                                 )
@@ -1958,61 +1964,76 @@ def test_transformed_constraints(self):
                 ]
             ),
         )
-        self.assertIsNone(cons1ub.lower)
-        self.assertEqual(cons1ub.upper, 0)
-        self.check_bigM_constraint(
-            cons1ub, m.z, 10, m.disjunct[1].innerdisjunct[0].indicator_var
+        assertExpressionsEqual(
+            self,
+            cons1ub.expr,
+            m.z
+            - 10.0
+            * (
+                1
+                - m.disjunct[1].innerdisjunct[0].binary_indicator_var
+                + 1
+                - m.disjunct[1].binary_indicator_var
+            )
+            <= 0.0,
         )
 
         cons2 = bigm.get_transformed_constraints(m.disjunct[1].innerdisjunct[1].c)
         self.assertEqual(len(cons2), 1)
         cons2lb = cons2[0]
-        self.assertEqual(cons2lb.lower, 5)
-        self.assertIsNone(cons2lb.upper)
-        self.check_bigM_constraint(
-            cons2lb, m.z, -5, m.disjunct[1].innerdisjunct[1].indicator_var
+        assertExpressionsEqual(
+            self,
+            cons2lb.expr,
+            5.0
+            <= m.z
+            - (-5.0)
+            * (
+                1
+                - m.disjunct[1].innerdisjunct[1].binary_indicator_var
+                + 1
+                - m.disjunct[1].binary_indicator_var
+            ),
         )
 
         cons3 = bigm.get_transformed_constraints(m.simpledisjunct.innerdisjunct0.c)
         self.assertEqual(len(cons3), 1)
         cons3ub = cons3[0]
-        self.assertEqual(cons3ub.upper, 2)
-        self.assertIsNone(cons3ub.lower)
-        self.check_bigM_constraint(
-            cons3ub, m.x, 7, m.simpledisjunct.innerdisjunct0.indicator_var
+        assertExpressionsEqual(
+            self,
+            cons3ub.expr,
+            m.x
+            - 7.0
+            * (
+                1
+                - m.simpledisjunct.innerdisjunct0.binary_indicator_var
+                + 1
+                - m.simpledisjunct.binary_indicator_var
+            )
+            <= 2.0,
         )
 
         cons4 = bigm.get_transformed_constraints(m.simpledisjunct.innerdisjunct1.c)
         self.assertEqual(len(cons4), 1)
         cons4lb = cons4[0]
-        self.assertEqual(cons4lb.lower, 4)
-        self.assertIsNone(cons4lb.upper)
-        self.check_bigM_constraint(
-            cons4lb, m.x, -13, m.simpledisjunct.innerdisjunct1.indicator_var
+        assertExpressionsEqual(
+            self,
+            cons4lb.expr,
+            m.x
+            - (-13.0)
+            * (
+                1
+                - m.simpledisjunct.innerdisjunct1.binary_indicator_var
+                + 1
+                - m.simpledisjunct.binary_indicator_var
+            )
+            >= 4.0,
         )
 
         # Here we check that the xor constraint from
         # simpledisjunct.innerdisjunction is transformed.
-        cons5 = m.simpledisjunct.innerdisjunction.algebraic_constraint
-        self.assertIsNotNone(cons5)
         self.check_inner_xor_constraint(
-            m.simpledisjunct.innerdisjunction,
-            m.simpledisjunct,
-            [m.simpledisjunct.innerdisjunct0, m.simpledisjunct.innerdisjunct1],
-        )
-        self.assertIsInstance(cons5, Constraint)
-        self.assertEqual(cons5.lower, 0)
-        self.assertEqual(cons5.upper, 0)
-        repn = generate_standard_repn(cons5.body)
-        self.assertTrue(repn.is_linear())
-        self.assertEqual(repn.constant, 0)
-        ct.check_linear_coef(
-            self, repn, m.simpledisjunct.innerdisjunct0.binary_indicator_var, 1
+            m.simpledisjunct.innerdisjunction, m.simpledisjunct, bigm
         )
-        ct.check_linear_coef(
-            self, repn, m.simpledisjunct.innerdisjunct1.binary_indicator_var, 1
-        )
-        ct.check_linear_coef(self, repn, m.simpledisjunct.binary_indicator_var, -1)
 
         cons6 = bigm.get_transformed_constraints(m.disjunct[0].c)
         self.assertEqual(len(cons6), 2)
@@ -2028,9 +2049,7 @@ def test_transformed_constraints(self):
         # now we check that the xor constraint from disjunct[1].innerdisjunction
         # is correct.
         self.check_inner_xor_constraint(
-            m.disjunct[1].innerdisjunction[0],
-            m.disjunct[1],
-            [m.disjunct[1].innerdisjunct[0], m.disjunct[1].innerdisjunct[1]],
+            m.disjunct[1].innerdisjunction[0], m.disjunct[1], bigm
         )
 
         cons8 = bigm.get_transformed_constraints(m.disjunct[1].c)
@@ -2107,34 +2126,18 @@ def innerIndexed(d, i):
                 m._pyomo_gdp_bigm_reformulation.relaxedDisjuncts,
             )
 
-    def check_first_disjunct_constraint(self, disj1c, x, ind_var):
-        self.assertEqual(len(disj1c), 1)
-        cons = disj1c[0]
-        self.assertIsNone(cons.lower)
-        self.assertEqual(cons.upper, 1)
-        repn = generate_standard_repn(cons.body)
-        self.assertTrue(repn.is_quadratic())
-        self.assertEqual(len(repn.linear_vars), 1)
-        self.assertEqual(len(repn.quadratic_vars), 4)
-        ct.check_linear_coef(self, repn, ind_var, 143)
-        self.assertEqual(repn.constant, -143)
-        for i in range(1, 5):
-            ct.check_squared_term_coef(self, repn, x[i], 1)
-
-    def check_second_disjunct_constraint(self, disj2c, x, ind_var):
-        self.assertEqual(len(disj2c), 1)
-        cons = disj2c[0]
-        self.assertIsNone(cons.lower)
-        self.assertEqual(cons.upper, 1)
-        repn = generate_standard_repn(cons.body)
-        self.assertTrue(repn.is_quadratic())
-        self.assertEqual(len(repn.linear_vars), 5)
-        self.assertEqual(len(repn.quadratic_vars), 4)
-        self.assertEqual(repn.constant, -63)  # M = 99, so this is 36 - 99
-        ct.check_linear_coef(self, repn, ind_var, 99)
-        for i in range(1, 5):
-            ct.check_squared_term_coef(self, repn, x[i], 1)
-            ct.check_linear_coef(self, repn, x[i], -6)
+    def simplify_cons(self, cons, leq):
+        visitor = LinearRepnVisitor({}, {}, {}, None)
+        repn = visitor.walk_expression(cons.body)
+        self.assertIsNone(repn.nonlinear)
+        if leq:
+            self.assertIsNone(cons.lower)
+            ub = cons.upper
+            return ub >= repn.to_expression(visitor)
+        else:
+            self.assertIsNone(cons.upper)
+            lb = cons.lower
+            return lb <= repn.to_expression(visitor)
 
     def check_hierarchical_nested_model(self, m, bigm):
         outer_xor = m.disjunction_block.disjunction.algebraic_constraint
@@ -2142,55 +2145,82 @@ def check_hierarchical_nested_model(self, m, bigm):
             self, outer_xor, m.disj1, m.disjunct_block.disj2
         )
 
-        inner_xor = m.disjunct_block.disj2.disjunction.algebraic_constraint
-        self.assertEqual(inner_xor.lower, 0)
-        self.assertEqual(inner_xor.upper, 0)
-        repn = generate_standard_repn(inner_xor.body)
-        self.assertTrue(repn.is_linear())
-        self.assertEqual(len(repn.linear_vars), 3)
-        self.assertEqual(repn.constant, 0)
-        ct.check_linear_coef(
-            self,
-            repn,
-            m.disjunct_block.disj2.disjunction_disjuncts[0].binary_indicator_var,
-            1,
-        )
-        ct.check_linear_coef(
-            self,
-            repn,
-            m.disjunct_block.disj2.disjunction_disjuncts[1].binary_indicator_var,
-            1,
-        )
-        ct.check_linear_coef(
-            self, repn, m.disjunct_block.disj2.binary_indicator_var, -1
+        self.check_inner_xor_constraint(
+            m.disjunct_block.disj2.disjunction, m.disjunct_block.disj2, bigm
         )
 
         # outer disjunction constraints
         disj1c = bigm.get_transformed_constraints(m.disj1.c)
-        self.check_first_disjunct_constraint(disj1c, m.x, m.disj1.binary_indicator_var)
+        self.assertEqual(len(disj1c), 1)
+        cons = disj1c[0]
+        assertExpressionsEqual(
+            self,
+            cons.expr,
+            m.x[1] ** 2
+            + m.x[2] ** 2
+            + m.x[3] ** 2
+            + m.x[4] ** 2
+            - 143.0 * (1 - m.disj1.binary_indicator_var)
+            <= 1.0,
+        )
 
         disj2c = bigm.get_transformed_constraints(m.disjunct_block.disj2.c)
-        self.check_second_disjunct_constraint(
-            disj2c, m.x, m.disjunct_block.disj2.binary_indicator_var
+        self.assertEqual(len(disj2c), 1)
+        cons = disj2c[0]
+        assertExpressionsEqual(
+            self,
+            cons.expr,
+            (3 - m.x[1]) ** 2
+            + (3 - m.x[2]) ** 2
+            + (3 - m.x[3]) ** 2
+            + (3 - m.x[4]) ** 2
+            - 99.0 * (1 - m.disjunct_block.disj2.binary_indicator_var)
+            <= 1.0,
         )
 
         # inner disjunction constraints
         innerd1c = bigm.get_transformed_constraints(
             m.disjunct_block.disj2.disjunction_disjuncts[0].constraint[1]
         )
-        self.check_first_disjunct_constraint(
-            innerd1c,
-            m.x,
-            m.disjunct_block.disj2.disjunction_disjuncts[0].binary_indicator_var,
+        self.assertEqual(len(innerd1c), 1)
+        cons = innerd1c[0]
+        assertExpressionsEqual(
+            self,
+            cons.expr,
+            m.x[1] ** 2
+            + m.x[2] ** 2
+            + m.x[3] ** 2
+            + m.x[4] ** 2
+            - 143.0
+            * (
+                1
+                - m.disjunct_block.disj2.disjunction_disjuncts[0].binary_indicator_var
+                + 1
+                - m.disjunct_block.disj2.binary_indicator_var
+            )
+            <= 1.0,
         )
 
         innerd2c = bigm.get_transformed_constraints(
             m.disjunct_block.disj2.disjunction_disjuncts[1].constraint[1]
         )
-        self.check_second_disjunct_constraint(
-            innerd2c,
-            m.x,
-            m.disjunct_block.disj2.disjunction_disjuncts[1].binary_indicator_var,
+        self.assertEqual(len(innerd2c), 1)
+        cons = innerd2c[0]
+        assertExpressionsEqual(
+            self,
+            cons.expr,
+            (3 - m.x[1]) ** 2
+            + (3 - m.x[2]) ** 2
+            + (3 - m.x[3]) ** 2
+            + (3 - m.x[4]) ** 2
+            - 99.0
+            * (
+                1
+                - m.disjunct_block.disj2.disjunction_disjuncts[1].binary_indicator_var
+                + 1
+                - m.disjunct_block.disj2.binary_indicator_var
+            )
+            <= 1.0,
         )
 
     def test_hierarchical_badly_ordered_targets(self):
@@ -2214,10 +2244,54 @@ def test_decl_order_opposite_instantiation_order(self):
         # the same check to make sure everything is transformed correctly.
         self.check_hierarchical_nested_model(m, bigm)
 
+    @unittest.skipUnless(gurobi_available, "Gurobi is not available")
+    def test_do_not_assume_nested_indicators_local(self):
+        ct.check_do_not_assume_nested_indicators_local(self, 'gdp.bigm')
+
+    @unittest.skipUnless(gurobi_available, "Gurobi is not available")
+    def test_constraints_not_enforced_when_an_ancestor_indicator_is_False(self):
+        m = ConcreteModel()
+        m.x = Var(bounds=(0, 30))
+
+        m.left = Disjunct()
+        m.left.left = Disjunct()
+        m.left.left.c = Constraint(expr=m.x >= 10)
+        m.left.right = Disjunct()
+        m.left.right.c = Constraint(expr=m.x >= 9)
+        m.left.disjunction = Disjunction(expr=[m.left.left, m.left.right])
+        m.right = Disjunct()
+        m.right.left = Disjunct()
+        m.right.left.c = Constraint(expr=m.x >= 11)
+        m.right.right = Disjunct()
+        m.right.right.c = Constraint(expr=m.x >= 8)
+        m.right.disjunction = Disjunction(expr=[m.right.left, m.right.right])
+        m.disjunction = Disjunction(expr=[m.left, m.right])
+
+        m.equiv_left = LogicalConstraint(
+            expr=m.left.left.indicator_var.equivalent_to(m.right.left.indicator_var)
+        )
+        m.equiv_right = LogicalConstraint(
+            expr=m.left.right.indicator_var.equivalent_to(m.right.right.indicator_var)
+        )
+
+        m.obj = Objective(expr=m.x)
+
+        TransformationFactory('gdp.bigm').apply_to(m)
+        results = SolverFactory('gurobi').solve(m)
+        self.assertEqual(
+            results.solver.termination_condition, TerminationCondition.optimal
+        )
+        self.assertTrue(value(m.right.indicator_var))
+        self.assertFalse(value(m.left.indicator_var))
+        self.assertTrue(value(m.right.right.indicator_var))
+        self.assertFalse(value(m.right.left.indicator_var))
+        self.assertTrue(value(m.left.right.indicator_var))
+        self.assertAlmostEqual(value(m.x), 8)
+
 
 class IndexedDisjunction(unittest.TestCase):
     # this tests that if the targets are a subset of the
-    # _DisjunctDatas in an IndexedDisjunction that the xor constraint
+    # DisjunctDatas in an IndexedDisjunction that the xor constraint
     # created on the parent block will still be indexed as expected.
     def test_xor_constraint(self):
         ct.check_indexed_xor_constraints_with_targets(self, 'bigm')
@@ -2282,18 +2356,12 @@ def check_all_but_evil1_b_anotherblock_constraint_transformed(self, m):
         self.assertEqual(len(evil1), 2)
         self.assertIs(evil1[0].parent_block(), disjBlock[1])
         self.assertIs(evil1[1].parent_block(), disjBlock[1])
-        out = StringIO()
-        with LoggingIntercept(out, 'pyomo.gdp', logging.ERROR):
-            self.assertRaisesRegex(
-                KeyError,
-                r".*.evil\[1\].b.anotherblock.c",
-                bigm.get_transformed_constraints,
-                m.evil[1].b.anotherblock.c,
-            )
-        self.assertRegex(
-            out.getvalue(),
-            r".*Constraint 'evil\[1\].b.anotherblock.c' has not been transformed.",
-        )
+        with self.assertRaisesRegex(
+            GDP_Error,
+            r"Constraint 'evil\[1\].b.anotherblock.c' has not been transformed.",
+        ):
+            bigm.get_transformed_constraints(m.evil[1].b.anotherblock.c)
+
         evil1 = bigm.get_transformed_constraints(m.evil[1].bb[1].c)
         self.assertEqual(len(evil1), 2)
         self.assertIs(evil1[0].parent_block(), disjBlock[1])
diff --git a/pyomo/gdp/tests/test_binary_multiplication.py b/pyomo/gdp/tests/test_binary_multiplication.py
new file mode 100644
index 00000000000..ae2c44b899e
--- /dev/null
+++ b/pyomo/gdp/tests/test_binary_multiplication.py
@@ -0,0 +1,312 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import pyomo.common.unittest as unittest
+
+from pyomo.environ import (
+    TransformationFactory,
+    Block,
+    Constraint,
+    ConcreteModel,
+    Var,
+    Any,
+    SolverFactory,
+)
+from pyomo.gdp import Disjunct, Disjunction
+from pyomo.core.expr.compare import assertExpressionsEqual
+from pyomo.repn import generate_standard_repn
+from pyomo.core.expr.compare import assertExpressionsEqual
+
+import pyomo.core.expr as EXPR
+import pyomo.gdp.tests.models as models
+import pyomo.gdp.tests.common_tests as ct
+
+import random
+
+gurobi_available = (
+    SolverFactory('gurobi').available(exception_flag=False)
+    and SolverFactory('gurobi').license_is_valid()
+)
+
+
+class CommonTests:
+    def diff_apply_to_and_create_using(self, model):
+        ct.diff_apply_to_and_create_using(self, model, 'gdp.binary_multiplication')
+
+
+class TwoTermDisj(unittest.TestCase, CommonTests):
+    def setUp(self):
+        # set seed so we can test name collisions predictably
+        random.seed(666)
+
+    def test_new_block_created(self):
+        m = models.makeTwoTermDisj()
+        TransformationFactory('gdp.binary_multiplication').apply_to(m)
+
+        # we have a transformation block
+        transBlock = m.component("_pyomo_gdp_binary_multiplication_reformulation")
+        self.assertIsInstance(transBlock, Block)
+
+        disjBlock = transBlock.component("relaxedDisjuncts")
+        self.assertIsInstance(disjBlock, Block)
+        self.assertEqual(len(disjBlock), 2)
+        # it has the disjuncts on it
+        self.assertIs(m.d[0].transformation_block, disjBlock[0])
+        self.assertIs(m.d[1].transformation_block, disjBlock[1])
+
+    def test_disjunction_deactivated(self):
+        ct.check_disjunction_deactivated(self, 'binary_multiplication')
+
+    def test_disjunctDatas_deactivated(self):
+        ct.check_disjunctDatas_deactivated(self, 'binary_multiplication')
+
+    def test_do_not_transform_twice_if_disjunction_reactivated(self):
+        ct.check_do_not_transform_twice_if_disjunction_reactivated(
+            self, 'binary_multiplication'
+        )
+
+    def test_xor_constraint_mapping(self):
+        ct.check_xor_constraint_mapping(self, 'binary_multiplication')
+
+    def test_xor_constraint_mapping_two_disjunctions(self):
+        ct.check_xor_constraint_mapping_two_disjunctions(self, 'binary_multiplication')
+
+    def test_disjunct_mapping(self):
+        ct.check_disjunct_mapping(self, 'binary_multiplication')
+
+    def test_disjunct_and_constraint_maps(self):
+        """Tests the actual data structures used to store the maps."""
+        m = models.makeTwoTermDisj()
+        binary_multiplication = TransformationFactory('gdp.binary_multiplication')
+        binary_multiplication.apply_to(m)
+        disjBlock = m._pyomo_gdp_binary_multiplication_reformulation.relaxedDisjuncts
+        oldblock = m.component("d")
+
+        # we are counting on the fact that the disjuncts get relaxed in the
+        # same order every time.
+        for i in [0, 1]:
+            self.assertIs(oldblock[i].transformation_block, disjBlock[i])
+            self.assertIs(
+                binary_multiplication.get_src_disjunct(disjBlock[i]), oldblock[i]
+            )
+
+        # check constraint dict has right mapping
+        c1_list = binary_multiplication.get_transformed_constraints(oldblock[1].c1)
+        # this is an equality
+        self.assertEqual(len(c1_list), 1)
+        self.assertIs(c1_list[0].parent_block(), disjBlock[1])
+        self.assertIs(
+            binary_multiplication.get_src_constraint(c1_list[0]), oldblock[1].c1
+        )
+
+        c2_list = binary_multiplication.get_transformed_constraints(oldblock[1].c2)
+        # just ub
+        self.assertEqual(len(c2_list), 1)
+        self.assertIs(c2_list[0].parent_block(), disjBlock[1])
+        self.assertIs(
+            binary_multiplication.get_src_constraint(c2_list[0]), oldblock[1].c2
+        )
+
+        c_list = binary_multiplication.get_transformed_constraints(oldblock[0].c)
+        # just lb
+        self.assertEqual(len(c_list), 1)
+        self.assertIs(c_list[0].parent_block(), disjBlock[0])
+        self.assertIs(
+            binary_multiplication.get_src_constraint(c_list[0]), oldblock[0].c
+        )
+
+    def test_new_block_nameCollision(self):
+        ct.check_transformation_block_name_collision(self, 'binary_multiplication')
+
+    def test_indicator_vars(self):
+        ct.check_indicator_vars(self, 'binary_multiplication')
+
+    def test_xor_constraints(self):
+        ct.check_xor_constraint(self, 'binary_multiplication')
+
+    def test_or_constraints(self):
+        m = models.makeTwoTermDisj()
+        m.disjunction.xor = False
+        TransformationFactory('gdp.binary_multiplication').apply_to(m)
+
+        # check or constraint is an or (upper bound is None)
+        orcons = m._pyomo_gdp_binary_multiplication_reformulation.component(
+            "disjunction_xor"
+        )
+        self.assertIsInstance(orcons, Constraint)
+        assertExpressionsEqual(
+            self,
+            orcons.body,
+            EXPR.LinearExpression(
+                [m.d[0].binary_indicator_var, m.d[1].binary_indicator_var]
+            ),
+        )
+        self.assertEqual(orcons.lower, 1)
+        self.assertIsNone(orcons.upper)
+
+    def test_deactivated_constraints(self):
+        ct.check_deactivated_constraints(self, 'binary_multiplication')
+
+    def test_transformed_constraints(self):
+        m = models.makeTwoTermDisj()
+        binary_multiplication = TransformationFactory('gdp.binary_multiplication')
+        binary_multiplication.apply_to(m)
+        self.check_transformed_constraints(m, binary_multiplication, -3, 2, 7, 2)
+
+    def test_do_not_transform_userDeactivated_disjuncts(self):
+        ct.check_user_deactivated_disjuncts(self, 'binary_multiplication')
+
+    def test_improperly_deactivated_disjuncts(self):
+        ct.check_improperly_deactivated_disjuncts(self, 'binary_multiplication')
+
+    def test_do_not_transform_userDeactivated_IndexedDisjunction(self):
+        ct.check_do_not_transform_userDeactivated_indexedDisjunction(
+            self, 'binary_multiplication'
+        )
+
+    def check_transformed_constraints(
+        self, model, binary_multiplication, cons1lb, cons2lb, cons2ub, cons3ub
+    ):
+        disjBlock = (
+            model._pyomo_gdp_binary_multiplication_reformulation.relaxedDisjuncts
+        )
+
+        # first constraint
+        c = binary_multiplication.get_transformed_constraints(model.d[0].c)
+        self.assertEqual(len(c), 1)
+        c_lb = c[0]
+        self.assertTrue(c[0].active)
+        ind_var = model.d[0].indicator_var
+        assertExpressionsEqual(
+            self, c[0].body, (model.a - model.d[0].c.lower) * ind_var
+        )
+        self.assertEqual(c[0].lower, 0)
+        self.assertIsNone(c[0].upper)
+
+        # second constraint
+        c = binary_multiplication.get_transformed_constraints(model.d[1].c1)
+        self.assertEqual(len(c), 1)
+        c_eq = c[0]
+        self.assertTrue(c[0].active)
+        ind_var = model.d[1].indicator_var
+        assertExpressionsEqual(self, c[0].body, model.a * ind_var)
+        self.assertEqual(c[0].lower, 0)
+        self.assertEqual(c[0].upper, 0)
+
+        # third constraint
+        c = binary_multiplication.get_transformed_constraints(model.d[1].c2)
+        self.assertEqual(len(c), 1)
+        c_ub = c[0]
+        self.assertTrue(c_ub.active)
+        assertExpressionsEqual(
+            self, c_ub.body, (model.x - model.d[1].c2.upper) * ind_var
+        )
+        self.assertIsNone(c_ub.lower)
+        self.assertEqual(c_ub.upper, 0)
+
+    def test_create_using(self):
+        m = models.makeTwoTermDisj()
+        self.diff_apply_to_and_create_using(m)
+
+    def test_indexed_constraints_in_disjunct(self):
+        m = ConcreteModel()
+        m.I = [1, 2, 3]
+        m.x = Var(m.I, bounds=(0, 10))
+
+        def c_rule(b, i):
+            m = b.model()
+            return m.x[i] >= i
+
+        def d_rule(d, j):
+            m = d.model()
+            d.c = Constraint(m.I[:j], rule=c_rule)
+
+        m.d = Disjunct(m.I, rule=d_rule)
+        m.disjunction = Disjunction(expr=[m.d[i] for i in m.I])
+
+        TransformationFactory('gdp.binary_multiplication').apply_to(m)
+        transBlock = m._pyomo_gdp_binary_multiplication_reformulation
+
+        # 2 blocks: the original Disjunct and the transformation block
+        self.assertEqual(len(list(m.component_objects(Block, descend_into=False))), 1)
+        self.assertEqual(len(list(m.component_objects(Disjunct))), 1)
+
+        # Each relaxed disjunct should have 1 var (the reference to the
+        # indicator var), and i "d[i].c" Constraints
+        for i in [1, 2, 3]:
+            relaxed = transBlock.relaxedDisjuncts[i - 1]
+            self.assertEqual(len(list(relaxed.component_objects(Var))), 1)
+            self.assertEqual(len(list(relaxed.component_data_objects(Var))), 1)
+            self.assertEqual(len(list(relaxed.component_objects(Constraint))), 1)
+            self.assertEqual(len(list(relaxed.component_data_objects(Constraint))), i)
+
+    def test_virtual_indexed_constraints_in_disjunct(self):
+        m = ConcreteModel()
+        m.I = [1, 2, 3]
+        m.x = Var(m.I, bounds=(0, 10))
+
+        def d_rule(d, j):
+            m = d.model()
+            d.c = Constraint(Any)
+            for k in range(j):
+                d.c[k + 1] = m.x[k + 1] >= k + 1
+
+        m.d = Disjunct(m.I, rule=d_rule)
+        m.disjunction = Disjunction(expr=[m.d[i] for i in m.I])
+
+        TransformationFactory('gdp.binary_multiplication').apply_to(m)
+        transBlock = m._pyomo_gdp_binary_multiplication_reformulation
+
+        # 2 blocks: the original Disjunct and the transformation block
+        self.assertEqual(len(list(m.component_objects(Block, descend_into=False))), 1)
+        self.assertEqual(len(list(m.component_objects(Disjunct))), 1)
+
+        # Each relaxed disjunct should have 1 var (the reference to the
+        # indicator var), and i "d[i].c" Constraints
+        for i in [1, 2, 3]:
+            relaxed = transBlock.relaxedDisjuncts[i - 1]
+            self.assertEqual(len(list(relaxed.component_objects(Var))), 1)
+            self.assertEqual(len(list(relaxed.component_data_objects(Var))), 1)
+            self.assertEqual(len(list(relaxed.component_objects(Constraint))), 1)
+            self.assertEqual(len(list(relaxed.component_data_objects(Constraint))), i)
+
+    def test_local_var(self):
+        m = models.localVar()
+        binary_multiplication = TransformationFactory('gdp.binary_multiplication')
+        binary_multiplication.apply_to(m)
+
+        # we just need to make sure that constraint was transformed correctly,
+        # which just means that the M values were correct.
+        transformedC = binary_multiplication.get_transformed_constraints(m.disj2.cons)
+        self.assertEqual(len(transformedC), 1)
+        eq = transformedC[0]
+        repn = generate_standard_repn(eq.body)
+        self.assertIsNone(repn.nonlinear_expr)
+        self.assertEqual(len(repn.linear_coefs), 1)
+        self.assertEqual(len(repn.quadratic_coefs), 2)
+        ct.check_linear_coef(self, repn, m.disj2.indicator_var, -3)
+        ct.check_quadratic_coef(self, repn, m.x, m.disj2.indicator_var, 1)
+        ct.check_quadratic_coef(self, repn, m.disj2.y, m.disj2.indicator_var, 1)
+        self.assertEqual(repn.constant, 0)
+        self.assertEqual(eq.lb, 0)
+        self.assertEqual(eq.ub, 0)
+
+
+class TestNestedGDP(unittest.TestCase):
+    @unittest.skipUnless(gurobi_available, "Gurobi is not available")
+    def test_do_not_assume_nested_indicators_local(self):
+        ct.check_do_not_assume_nested_indicators_local(
+            self, 'gdp.binary_multiplication'
+        )
+
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/pyomo/gdp/tests/test_bound_pretransformation.py b/pyomo/gdp/tests/test_bound_pretransformation.py
index 30ce76b7e31..68db64ce93b 100644
--- a/pyomo/gdp/tests/test_bound_pretransformation.py
+++ b/pyomo/gdp/tests/test_bound_pretransformation.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/gdp/tests/test_cuttingplane.py b/pyomo/gdp/tests/test_cuttingplane.py
index 827eac9aa6a..153e236942d 100644
--- a/pyomo/gdp/tests/test_cuttingplane.py
+++ b/pyomo/gdp/tests/test_cuttingplane.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/gdp/tests/test_disjunct.py b/pyomo/gdp/tests/test_disjunct.py
index 676b49a80cd..f93ac31fb0f 100644
--- a/pyomo/gdp/tests/test_disjunct.py
+++ b/pyomo/gdp/tests/test_disjunct.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -632,19 +632,13 @@ def test_cast_to_binary(self):
         out = StringIO()
         with LoggingIntercept(out):
             e = m.iv + 1
-        assertExpressionsEqual(
-            self, e, EXPR.LinearExpression([EXPR.MonomialTermExpression((1, m.biv)), 1])
-        )
+        assertExpressionsEqual(self, e, EXPR.LinearExpression([m.biv, 1]))
         self.assertIn(deprecation_msg, out.getvalue())
 
         out = StringIO()
         with LoggingIntercept(out):
             e = m.iv - 1
-        assertExpressionsEqual(
-            self,
-            e,
-            EXPR.LinearExpression([EXPR.MonomialTermExpression((1, m.biv)), -1]),
-        )
+        assertExpressionsEqual(self, e, EXPR.LinearExpression([m.biv, -1]))
         self.assertIn(deprecation_msg, out.getvalue())
 
         out = StringIO()
@@ -665,9 +659,7 @@ def test_cast_to_binary(self):
         out = StringIO()
         with LoggingIntercept(out):
             e = 1 + m.iv
-        assertExpressionsEqual(
-            self, e, EXPR.LinearExpression([1, EXPR.MonomialTermExpression((1, m.biv))])
-        )
+        assertExpressionsEqual(self, e, EXPR.LinearExpression([1, m.biv]))
         self.assertIn(deprecation_msg, out.getvalue())
 
         out = StringIO()
@@ -699,20 +691,14 @@ def test_cast_to_binary(self):
         with LoggingIntercept(out):
             a = m.iv
             a += 1
-        assertExpressionsEqual(
-            self, a, EXPR.LinearExpression([EXPR.MonomialTermExpression((1, m.biv)), 1])
-        )
+        assertExpressionsEqual(self, a, EXPR.LinearExpression([m.biv, 1]))
         self.assertIn(deprecation_msg, out.getvalue())
 
         out = StringIO()
         with LoggingIntercept(out):
             a = m.iv
             a -= 1
-        assertExpressionsEqual(
-            self,
-            a,
-            EXPR.LinearExpression([EXPR.MonomialTermExpression((1, m.biv)), -1]),
-        )
+        assertExpressionsEqual(self, a, EXPR.LinearExpression([m.biv, -1]))
         self.assertIn(deprecation_msg, out.getvalue())
 
         out = StringIO()
diff --git a/pyomo/gdp/tests/test_fix_disjuncts.py b/pyomo/gdp/tests/test_fix_disjuncts.py
index 1b741f7a840..6f01e096e9d 100644
--- a/pyomo/gdp/tests/test_fix_disjuncts.py
+++ b/pyomo/gdp/tests/test_fix_disjuncts.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/gdp/tests/test_gdp.py b/pyomo/gdp/tests/test_gdp.py
index 5c810dcce18..b22a60bc04a 100644
--- a/pyomo/gdp/tests/test_gdp.py
+++ b/pyomo/gdp/tests/test_gdp.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/gdp/tests/test_gdp_reclassification_error.py b/pyomo/gdp/tests/test_gdp_reclassification_error.py
index a65ccac2d8f..556dc44eead 100644
--- a/pyomo/gdp/tests/test_gdp_reclassification_error.py
+++ b/pyomo/gdp/tests/test_gdp_reclassification_error.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/gdp/tests/test_hull.py b/pyomo/gdp/tests/test_hull.py
index 09f65765fe6..07876a9d213 100644
--- a/pyomo/gdp/tests/test_hull.py
+++ b/pyomo/gdp/tests/test_hull.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -41,6 +41,7 @@
 import pyomo.core.expr as EXPR
 from pyomo.core.base import constraint
 from pyomo.repn import generate_standard_repn
+from pyomo.repn.linear import LinearRepnVisitor
 
 from pyomo.gdp import Disjunct, Disjunction, GDP_Error
 import pyomo.gdp.tests.models as models
@@ -51,6 +52,7 @@
 import os
 from os.path import abspath, dirname, join
 
+
 currdir = dirname(abspath(__file__))
 from filecmp import cmp
 
@@ -402,19 +404,13 @@ def test_error_for_or(self):
         self.assertRaisesRegex(
             GDP_Error,
             "Cannot do hull reformulation for Disjunction "
-            "'disjunction' with OR constraint.  Must be an XOR!*",
+            "'disjunction' with OR constraint. Must be an XOR!*",
             TransformationFactory('gdp.hull').apply_to,
             m,
         )
 
     def check_disaggregation_constraint(self, cons, var, disvar1, disvar2):
-        repn = generate_standard_repn(cons.body)
-        self.assertEqual(cons.lower, 0)
-        self.assertEqual(cons.upper, 0)
-        self.assertEqual(len(repn.linear_vars), 3)
-        ct.check_linear_coef(self, repn, var, 1)
-        ct.check_linear_coef(self, repn, disvar1, -1)
-        ct.check_linear_coef(self, repn, disvar2, -1)
+        assertExpressionsEqual(self, cons.expr, var == disvar1 + disvar2)
 
     def test_disaggregation_constraint(self):
         m = models.makeTwoTermDisj_Nonlinear()
@@ -426,8 +422,8 @@ def test_disaggregation_constraint(self):
         self.check_disaggregation_constraint(
             hull.get_disaggregation_constraint(m.w, m.disjunction),
             m.w,
-            disjBlock[1].disaggregatedVars.w,
             transBlock._disaggregatedVars[1],
+            disjBlock[1].disaggregatedVars.w,
         )
         self.check_disaggregation_constraint(
             hull.get_disaggregation_constraint(m.x, m.disjunction),
@@ -438,8 +434,8 @@ def test_disaggregation_constraint(self):
         self.check_disaggregation_constraint(
             hull.get_disaggregation_constraint(m.y, m.disjunction),
             m.y,
-            disjBlock[0].disaggregatedVars.y,
             transBlock._disaggregatedVars[0],
+            disjBlock[0].disaggregatedVars.y,
         )
 
     def test_xor_constraint_mapping(self):
@@ -510,10 +506,10 @@ def test_disaggregatedVar_mappings(self):
         for i in [0, 1]:
             mappings = ComponentMap()
             mappings[m.x] = disjBlock[i].disaggregatedVars.x
-            if i == 1:  # this disjunct as x, w, and no y
+            if i == 1:  # this disjunct has x, w, and no y
                 mappings[m.w] = disjBlock[i].disaggregatedVars.w
                 mappings[m.y] = transBlock._disaggregatedVars[0]
-            elif i == 0:  # this disjunct as x, y, and no w
+            elif i == 0:  # this disjunct has x, y, and no w
                 mappings[m.y] = disjBlock[i].disaggregatedVars.y
                 mappings[m.w] = transBlock._disaggregatedVars[1]
 
@@ -668,17 +664,38 @@ def test_global_vars_local_to_a_disjunction_disaggregated(self):
         self.assertIs(hull.get_src_var(x), m.disj1.x)
 
         # there is a spare x on disjunction1's block
-        x2 = m.disjunction1.algebraic_constraint.parent_block()._disaggregatedVars[2]
+        x2 = m.disjunction1.algebraic_constraint.parent_block()._disaggregatedVars[0]
         self.assertIs(hull.get_disaggregated_var(m.disj1.x, m.disj2), x2)
         self.assertIs(hull.get_src_var(x2), m.disj1.x)
+        # What really matters is that the above matches this:
+        agg_cons = hull.get_disaggregation_constraint(m.disj1.x, m.disjunction1)
+        assertExpressionsEqual(
+            self,
+            agg_cons.expr,
+            m.disj1.x == x2 + hull.get_disaggregated_var(m.disj1.x, m.disj1),
+        )
 
         # and both a spare x and y on disjunction2's block
-        x2 = m.disjunction2.algebraic_constraint.parent_block()._disaggregatedVars[0]
-        y1 = m.disjunction2.algebraic_constraint.parent_block()._disaggregatedVars[1]
+        x2 = m.disjunction2.algebraic_constraint.parent_block()._disaggregatedVars[1]
+        y1 = m.disjunction2.algebraic_constraint.parent_block()._disaggregatedVars[2]
         self.assertIs(hull.get_disaggregated_var(m.disj1.x, m.disj4), x2)
         self.assertIs(hull.get_src_var(x2), m.disj1.x)
         self.assertIs(hull.get_disaggregated_var(m.disj1.y, m.disj3), y1)
         self.assertIs(hull.get_src_var(y1), m.disj1.y)
+        # and again what really matters is that these align with the
+        # disaggregation constraints:
+        agg_cons = hull.get_disaggregation_constraint(m.disj1.x, m.disjunction2)
+        assertExpressionsEqual(
+            self,
+            agg_cons.expr,
+            m.disj1.x == x2 + hull.get_disaggregated_var(m.disj1.x, m.disj3),
+        )
+        agg_cons = hull.get_disaggregation_constraint(m.disj1.y, m.disjunction2)
+        assertExpressionsEqual(
+            self,
+            agg_cons.expr,
+            m.disj1.y == y1 + hull.get_disaggregated_var(m.disj1.y, m.disj4),
+        )
 
     def check_name_collision_disaggregated_vars(self, m, disj):
         hull = TransformationFactory('gdp.hull')
@@ -880,18 +897,10 @@ def test_do_not_transform_deactivated_constraintDatas(self):
         hull = TransformationFactory('gdp.hull')
         hull.apply_to(m)
         # can't ask for simpledisj1.c[1]: it wasn't transformed
-        log = StringIO()
-        with LoggingIntercept(log, 'pyomo.gdp', logging.ERROR):
-            self.assertRaisesRegex(
-                KeyError,
-                r".*b.simpledisj1.c\[1\]",
-                hull.get_transformed_constraints,
-                m.b.simpledisj1.c[1],
-            )
-        self.assertRegex(
-            log.getvalue(),
-            r".*Constraint 'b.simpledisj1.c\[1\]' has not been transformed.",
-        )
+        with self.assertRaisesRegex(
+            GDP_Error, r"Constraint 'b.simpledisj1.c\[1\]' has not been transformed."
+        ):
+            hull.get_transformed_constraints(m.b.simpledisj1.c[1])
 
         # this fixes a[2] to 0, so we should get the disggregated var
         transformed = hull.get_transformed_constraints(m.b.simpledisj1.c[2])
@@ -1101,7 +1110,7 @@ def check_trans_block_disjunctions_of_disjunct_datas(self, m):
         self.assertEqual(len(transBlock1.relaxedDisjuncts), 4)
 
         hull = TransformationFactory('gdp.hull')
-        firstTerm2 = transBlock1.relaxedDisjuncts[0]
+        firstTerm2 = transBlock1.relaxedDisjuncts[2]
         self.assertIs(firstTerm2, m.firstTerm[2].transformation_block)
         self.assertIsInstance(firstTerm2.disaggregatedVars.component("x"), Var)
         constraints = hull.get_transformed_constraints(m.firstTerm[2].cons)
@@ -1115,7 +1124,7 @@ def check_trans_block_disjunctions_of_disjunct_datas(self, m):
         self.assertIs(cons.parent_block(), firstTerm2)
         self.assertEqual(len(cons), 2)
 
-        secondTerm2 = transBlock1.relaxedDisjuncts[1]
+        secondTerm2 = transBlock1.relaxedDisjuncts[3]
         self.assertIs(secondTerm2, m.secondTerm[2].transformation_block)
         self.assertIsInstance(secondTerm2.disaggregatedVars.component("x"), Var)
         constraints = hull.get_transformed_constraints(m.secondTerm[2].cons)
@@ -1129,7 +1138,7 @@ def check_trans_block_disjunctions_of_disjunct_datas(self, m):
         self.assertIs(cons.parent_block(), secondTerm2)
         self.assertEqual(len(cons), 2)
 
-        firstTerm1 = transBlock1.relaxedDisjuncts[2]
+        firstTerm1 = transBlock1.relaxedDisjuncts[0]
         self.assertIs(firstTerm1, m.firstTerm[1].transformation_block)
         self.assertIsInstance(firstTerm1.disaggregatedVars.component("x"), Var)
         self.assertTrue(firstTerm1.disaggregatedVars.x.is_fixed())
@@ -1147,7 +1156,7 @@ def check_trans_block_disjunctions_of_disjunct_datas(self, m):
         self.assertIs(cons.parent_block(), firstTerm1)
         self.assertEqual(len(cons), 2)
 
-        secondTerm1 = transBlock1.relaxedDisjuncts[3]
+        secondTerm1 = transBlock1.relaxedDisjuncts[1]
         self.assertIs(secondTerm1, m.secondTerm[1].transformation_block)
         self.assertIsInstance(secondTerm1.disaggregatedVars.component("x"), Var)
         constraints = hull.get_transformed_constraints(m.secondTerm[1].cons)
@@ -1243,12 +1252,10 @@ def check_second_iteration(self, model):
 
         orig = model.component("_pyomo_gdp_hull_reformulation")
         self.assertIsInstance(
-            model.disjunctionList[1].algebraic_constraint,
-            constraint._GeneralConstraintData,
+            model.disjunctionList[1].algebraic_constraint, constraint.ConstraintData
         )
         self.assertIsInstance(
-            model.disjunctionList[0].algebraic_constraint,
-            constraint._GeneralConstraintData,
+            model.disjunctionList[0].algebraic_constraint, constraint.ConstraintData
         )
         self.assertFalse(model.disjunctionList[1].active)
         self.assertFalse(model.disjunctionList[0].active)
@@ -1375,9 +1382,8 @@ def test_deactivated_disjunct_leaves_nested_disjuncts_active(self):
         ct.check_deactivated_disjunct_leaves_nested_disjunct_active(self, 'hull')
 
     def test_mappings_between_disjunctions_and_xors(self):
-        # This test is nearly identical to the one in bigm, but because of
-        # different transformation orders, the name conflict gets resolved in
-        # the opposite way.
+        # Tests that the XOR constraints are put on the parent block of the
+        # disjunction, and checks the mappings.
         m = models.makeNestedDisjunctions()
         transform = TransformationFactory('gdp.hull')
         transform.apply_to(m)
@@ -1386,8 +1392,17 @@ def test_mappings_between_disjunctions_and_xors(self):
 
         disjunctionPairs = [
             (m.disjunction, transBlock.disjunction_xor),
-            (m.disjunct[1].innerdisjunction[0], transBlock.innerdisjunction_xor[0]),
-            (m.simpledisjunct.innerdisjunction, transBlock.innerdisjunction_xor_4),
+            (
+                m.disjunct[1].innerdisjunction[0],
+                m.disjunct[1]
+                .innerdisjunction[0]
+                .algebraic_constraint.parent_block()
+                .innerdisjunction_xor[0],
+            ),
+            (
+                m.simpledisjunct.innerdisjunction,
+                m.simpledisjunct.innerdisjunction.algebraic_constraint.parent_block().innerdisjunction_xor,
+            ),
         ]
 
         # check disjunction mappings
@@ -1427,16 +1442,16 @@ def test_relaxation_feasibility(self):
         solver = SolverFactory(linear_solvers[0])
 
         cases = [
-            (1, 1, 1, 1, None),
-            (0, 0, 0, 0, None),
-            (1, 0, 0, 0, None),
-            (0, 1, 0, 0, 1.1),
-            (0, 0, 1, 0, None),
-            (0, 0, 0, 1, None),
-            (1, 1, 0, 0, None),
-            (1, 0, 1, 0, 1.2),
-            (1, 0, 0, 1, 1.3),
-            (1, 0, 1, 1, None),
+            (True, True, True, True, None),
+            (False, False, False, False, None),
+            (True, False, False, False, None),
+            (False, True, False, False, 1.1),
+            (False, False, True, False, None),
+            (False, False, False, True, None),
+            (True, True, False, False, None),
+            (True, False, True, False, 1.2),
+            (True, False, False, True, 1.3),
+            (True, False, True, True, None),
         ]
         for case in cases:
             m.d1.indicator_var.fix(case[0])
@@ -1468,16 +1483,16 @@ def test_relaxation_feasibility_transform_inner_first(self):
         solver = SolverFactory(linear_solvers[0])
 
         cases = [
-            (1, 1, 1, 1, None),
-            (0, 0, 0, 0, None),
-            (1, 0, 0, 0, None),
-            (0, 1, 0, 0, 1.1),
-            (0, 0, 1, 0, None),
-            (0, 0, 0, 1, None),
-            (1, 1, 0, 0, None),
-            (1, 0, 1, 0, 1.2),
-            (1, 0, 0, 1, 1.3),
-            (1, 0, 1, 1, None),
+            (True, True, True, True, None),
+            (False, False, False, False, None),
+            (True, False, False, False, None),
+            (False, True, False, False, 1.1),
+            (False, False, True, False, None),
+            (False, False, False, True, None),
+            (True, True, False, False, None),
+            (True, False, True, False, 1.2),
+            (True, False, False, True, 1.3),
+            (True, False, True, True, None),
         ]
         for case in cases:
             m.d1.indicator_var.fix(case[0])
@@ -1550,149 +1565,190 @@ def check_transformed_constraint(self, cons, dis, lb, ind_var):
     def test_transformed_model_nestedDisjuncts(self):
         # This test tests *everything* for a simple nested disjunction case.
         m = models.makeNestedDisjunctions_NestedDisjuncts()
+        m.LocalVars = Suffix(direction=Suffix.LOCAL)
+        m.LocalVars[m.d1] = [
+            m.d1.binary_indicator_var,
+            m.d1.d3.binary_indicator_var,
+            m.d1.d4.binary_indicator_var,
+        ]
 
         hull = TransformationFactory('gdp.hull')
         hull.apply_to(m)
 
+        self.check_transformed_model_nestedDisjuncts(
+            m, m.d1.d3.binary_indicator_var, m.d1.d4.binary_indicator_var
+        )
+
+        # Last, check that there aren't things we weren't expecting
+        all_cons = list(
+            m.component_data_objects(Constraint, active=True, descend_into=Block)
+        )
+        # 2 disaggregation constraints for x 0,3
+        # + 6 bounds constraints for x 6,8,9,13,14,16
+        # + 2 bounds constraints for inner indicator vars 11, 12
+        # + 2 exactly-one constraints 1,4
+        # + 4 transformed constraints 2,5,7,15
+        self.assertEqual(len(all_cons), 16)
+
+    def check_transformed_model_nestedDisjuncts(self, m, d3, d4):
+        # This function checks all of the 16 constraint expressions from
+        # transforming models.makeNestedDisjunction_NestedDisjuncts when
+        # declaring the inner indicator vars (d3 and d4) as local. Note that it
+        # also is a correct test for the case where the inner indicator vars are
+        # *not* declared as local, but not a complete one, since there are
+        # additional constraints in that case (see
+        # check_transformation_blocks_nestedDisjunctions in common_tests.py).
+        hull = TransformationFactory('gdp.hull')
         transBlock = m._pyomo_gdp_hull_reformulation
         self.assertTrue(transBlock.active)
 
-        # outer xor should be on this block
+        # check outer xor
         xor = transBlock.disj_xor
         self.assertIsInstance(xor, Constraint)
-        self.assertTrue(xor.active)
-        self.assertEqual(xor.lower, 1)
-        self.assertEqual(xor.upper, 1)
-        repn = generate_standard_repn(xor.body)
-        self.assertTrue(repn.is_linear())
-        self.assertEqual(repn.constant, 0)
-        ct.check_linear_coef(self, repn, m.d1.binary_indicator_var, 1)
-        ct.check_linear_coef(self, repn, m.d2.binary_indicator_var, 1)
+        ct.check_obj_in_active_tree(self, xor)
+        assertExpressionsEqual(
+            self, xor.expr, m.d1.binary_indicator_var + m.d2.binary_indicator_var == 1
+        )
         self.assertIs(xor, m.disj.algebraic_constraint)
         self.assertIs(m.disj, hull.get_src_disjunction(xor))
 
-        # inner xor should be on this block
+        # check inner xor
         xor = m.d1.disj2.algebraic_constraint
-        self.assertIs(xor.parent_block(), transBlock)
-        self.assertIsInstance(xor, Constraint)
-        self.assertTrue(xor.active)
-        self.assertEqual(xor.lower, 0)
-        self.assertEqual(xor.upper, 0)
-        repn = generate_standard_repn(xor.body)
-        self.assertTrue(repn.is_linear())
-        self.assertEqual(repn.constant, 0)
-        ct.check_linear_coef(self, repn, m.d1.d3.binary_indicator_var, 1)
-        ct.check_linear_coef(self, repn, m.d1.d4.binary_indicator_var, 1)
-        ct.check_linear_coef(self, repn, m.d1.binary_indicator_var, -1)
         self.assertIs(m.d1.disj2, hull.get_src_disjunction(xor))
-
-        # so should both disaggregation constraints
-        dis = transBlock.disaggregationConstraints
-        self.assertIsInstance(dis, Constraint)
-        self.assertTrue(dis.active)
-        self.assertEqual(len(dis), 2)
-        self.check_outer_disaggregation_constraint(dis[0], m.x, m.d1, m.d2)
-        self.assertIs(hull.get_disaggregation_constraint(m.x, m.disj), dis[0])
-        self.check_outer_disaggregation_constraint(
-            dis[1], m.x, m.d1.d3, m.d1.d4, rhs=hull.get_disaggregated_var(m.x, m.d1)
-        )
-        self.assertIs(hull.get_disaggregation_constraint(m.x, m.d1.disj2), dis[1])
-
-        # we should have four disjunct transformation blocks
-        disjBlocks = transBlock.relaxedDisjuncts
-        self.assertTrue(disjBlocks.active)
-        self.assertEqual(len(disjBlocks), 4)
-
-        ## d1's transformation block
-
-        disj1 = disjBlocks[0]
-        self.assertTrue(disj1.active)
-        self.assertIs(disj1, m.d1.transformation_block)
-        self.assertIs(m.d1, hull.get_src_disjunct(disj1))
-        # check the disaggregated x is here
-        self.assertIsInstance(disj1.disaggregatedVars.x, Var)
-        self.assertEqual(disj1.disaggregatedVars.x.lb, 0)
-        self.assertEqual(disj1.disaggregatedVars.x.ub, 2)
-        self.assertIs(disj1.disaggregatedVars.x, hull.get_disaggregated_var(m.x, m.d1))
-        self.assertIs(m.x, hull.get_src_var(disj1.disaggregatedVars.x))
-        # check the bounds constraints
-        self.check_bounds_constraint_ub(
-            disj1.x_bounds, 2, disj1.disaggregatedVars.x, m.d1.indicator_var
-        )
-        # transformed constraint x >= 1
-        cons = hull.get_transformed_constraints(m.d1.c)
-        self.check_transformed_constraint(
-            cons, disj1.disaggregatedVars.x, 1, m.d1.indicator_var
+        xor = hull.get_transformed_constraints(xor)
+        self.assertEqual(len(xor), 1)
+        xor = xor[0]
+        ct.check_obj_in_active_tree(self, xor)
+        xor_expr = self.simplify_cons(xor)
+        assertExpressionsEqual(
+            self, xor_expr, d3 + d4 - m.d1.binary_indicator_var == 0.0
         )
 
-        ## d2's transformation block
+        # check disaggregation constraints
+        x_d3 = hull.get_disaggregated_var(m.x, m.d1.d3)
+        x_d4 = hull.get_disaggregated_var(m.x, m.d1.d4)
+        x_d1 = hull.get_disaggregated_var(m.x, m.d1)
+        x_d2 = hull.get_disaggregated_var(m.x, m.d2)
+        for x in [x_d1, x_d2, x_d3, x_d4]:
+            self.assertEqual(x.lb, 0)
+            self.assertEqual(x.ub, 2)
+        # Inner disjunction
+        cons = hull.get_disaggregation_constraint(m.x, m.d1.disj2)
+        ct.check_obj_in_active_tree(self, cons)
+        cons_expr = self.simplify_cons(cons)
+        assertExpressionsEqual(self, cons_expr, x_d1 - x_d3 - x_d4 == 0.0)
+        # Outer disjunction
+        cons = hull.get_disaggregation_constraint(m.x, m.disj)
+        ct.check_obj_in_active_tree(self, cons)
+        cons_expr = self.simplify_cons(cons)
+        assertExpressionsEqual(self, cons_expr, m.x - x_d1 - x_d2 == 0.0)
 
-        disj2 = disjBlocks[1]
-        self.assertTrue(disj2.active)
-        self.assertIs(disj2, m.d2.transformation_block)
-        self.assertIs(m.d2, hull.get_src_disjunct(disj2))
-        # disaggregated var
-        x2 = disj2.disaggregatedVars.x
-        self.assertIsInstance(x2, Var)
-        self.assertEqual(x2.lb, 0)
-        self.assertEqual(x2.ub, 2)
-        self.assertIs(hull.get_disaggregated_var(m.x, m.d2), x2)
-        self.assertIs(hull.get_src_var(x2), m.x)
-        # bounds constraint
-        x_bounds = disj2.x_bounds
-        self.check_bounds_constraint_ub(x_bounds, 2, x2, m.d2.binary_indicator_var)
-        # transformed constraint x >= 1.1
-        cons = hull.get_transformed_constraints(m.d2.c)
-        self.check_transformed_constraint(cons, x2, 1.1, m.d2.binary_indicator_var)
-
-        ## d1.d3's transformation block
-
-        disj3 = disjBlocks[2]
-        self.assertTrue(disj3.active)
-        self.assertIs(disj3, m.d1.d3.transformation_block)
-        self.assertIs(m.d1.d3, hull.get_src_disjunct(disj3))
-        # disaggregated var
-        x3 = disj3.disaggregatedVars.x
-        self.assertIsInstance(x3, Var)
-        self.assertEqual(x3.lb, 0)
-        self.assertEqual(x3.ub, 2)
-        self.assertIs(hull.get_disaggregated_var(m.x, m.d1.d3), x3)
-        self.assertIs(hull.get_src_var(x3), m.x)
-        # bounds constraints
-        self.check_bounds_constraint_ub(
-            disj3.x_bounds, 2, x3, m.d1.d3.binary_indicator_var
-        )
-        # transformed x >= 1.2
+        ## Transformed constraints
         cons = hull.get_transformed_constraints(m.d1.d3.c)
-        self.check_transformed_constraint(cons, x3, 1.2, m.d1.d3.binary_indicator_var)
-
-        ## d1.d4's transformation block
-
-        disj4 = disjBlocks[3]
-        self.assertTrue(disj4.active)
-        self.assertIs(disj4, m.d1.d4.transformation_block)
-        self.assertIs(m.d1.d4, hull.get_src_disjunct(disj4))
-        # disaggregated var
-        x4 = disj4.disaggregatedVars.x
-        self.assertIsInstance(x4, Var)
-        self.assertEqual(x4.lb, 0)
-        self.assertEqual(x4.ub, 2)
-        self.assertIs(hull.get_disaggregated_var(m.x, m.d1.d4), x4)
-        self.assertIs(hull.get_src_var(x4), m.x)
-        # bounds constraints
-        self.check_bounds_constraint_ub(
-            disj4.x_bounds, 2, x4, m.d1.d4.binary_indicator_var
-        )
-        # transformed x >= 1.3
+        self.assertEqual(len(cons), 1)
+        cons = cons[0]
+        ct.check_obj_in_active_tree(self, cons)
+        cons_expr = self.simplify_leq_cons(cons)
+        assertExpressionsEqual(self, cons_expr, 1.2 * d3 - x_d3 <= 0.0)
+
         cons = hull.get_transformed_constraints(m.d1.d4.c)
-        self.check_transformed_constraint(cons, x4, 1.3, m.d1.d4.binary_indicator_var)
+        self.assertEqual(len(cons), 1)
+        cons = cons[0]
+        ct.check_obj_in_active_tree(self, cons)
+        cons_expr = self.simplify_leq_cons(cons)
+        assertExpressionsEqual(self, cons_expr, 1.3 * d4 - x_d4 <= 0.0)
+
+        cons = hull.get_transformed_constraints(m.d1.c)
+        self.assertEqual(len(cons), 1)
+        cons = cons[0]
+        ct.check_obj_in_active_tree(self, cons)
+        cons_expr = self.simplify_leq_cons(cons)
+        assertExpressionsEqual(
+            self, cons_expr, 1.0 * m.d1.binary_indicator_var - x_d1 <= 0.0
+        )
+
+        cons = hull.get_transformed_constraints(m.d2.c)
+        self.assertEqual(len(cons), 1)
+        cons = cons[0]
+        ct.check_obj_in_active_tree(self, cons)
+        cons_expr = self.simplify_leq_cons(cons)
+        assertExpressionsEqual(
+            self, cons_expr, 1.1 * m.d2.binary_indicator_var - x_d2 <= 0.0
+        )
+
+        ## Bounds constraints
+        cons = hull.get_var_bounds_constraint(x_d1)
+        # the lb is trivial in this case, so we just have 1
+        self.assertEqual(len(cons), 1)
+        ct.check_obj_in_active_tree(self, cons['ub'])
+        cons_expr = self.simplify_leq_cons(cons['ub'])
+        assertExpressionsEqual(
+            self, cons_expr, x_d1 - 2 * m.d1.binary_indicator_var <= 0.0
+        )
+        cons = hull.get_var_bounds_constraint(x_d2)
+        # the lb is trivial in this case, so we just have 1
+        self.assertEqual(len(cons), 1)
+        ct.check_obj_in_active_tree(self, cons['ub'])
+        cons_expr = self.simplify_leq_cons(cons['ub'])
+        assertExpressionsEqual(
+            self, cons_expr, x_d2 - 2 * m.d2.binary_indicator_var <= 0.0
+        )
+        cons = hull.get_var_bounds_constraint(x_d3, m.d1.d3)
+        # the lb is trivial in this case, so we just have 1
+        self.assertEqual(len(cons), 1)
+        # And we know it has actually been transformed again, so get that one
+        cons = hull.get_transformed_constraints(cons['ub'])
+        self.assertEqual(len(cons), 1)
+        ub = cons[0]
+        ct.check_obj_in_active_tree(self, ub)
+        cons_expr = self.simplify_leq_cons(ub)
+        assertExpressionsEqual(self, cons_expr, x_d3 - 2 * d3 <= 0.0)
+        cons = hull.get_var_bounds_constraint(x_d4, m.d1.d4)
+        # the lb is trivial in this case, so we just have 1
+        self.assertEqual(len(cons), 1)
+        # And we know it has actually been transformed again, so get that one
+        cons = hull.get_transformed_constraints(cons['ub'])
+        self.assertEqual(len(cons), 1)
+        ub = cons[0]
+        ct.check_obj_in_active_tree(self, ub)
+        cons_expr = self.simplify_leq_cons(ub)
+        assertExpressionsEqual(self, cons_expr, x_d4 - 2 * d4 <= 0.0)
+        cons = hull.get_var_bounds_constraint(x_d3, m.d1)
+        self.assertEqual(len(cons), 1)
+        ub = cons['ub']
+        ct.check_obj_in_active_tree(self, ub)
+        cons_expr = self.simplify_leq_cons(ub)
+        assertExpressionsEqual(
+            self, cons_expr, x_d3 - 2 * m.d1.binary_indicator_var <= 0.0
+        )
+        cons = hull.get_var_bounds_constraint(x_d4, m.d1)
+        self.assertEqual(len(cons), 1)
+        ub = cons['ub']
+        ct.check_obj_in_active_tree(self, ub)
+        cons_expr = self.simplify_leq_cons(ub)
+        assertExpressionsEqual(
+            self, cons_expr, x_d4 - 2 * m.d1.binary_indicator_var <= 0.0
+        )
+
+        # Bounds constraints for local vars
+        cons = hull.get_var_bounds_constraint(d3)
+        ct.check_obj_in_active_tree(self, cons['ub'])
+        assertExpressionsEqual(self, cons['ub'].expr, d3 <= m.d1.binary_indicator_var)
+        cons = hull.get_var_bounds_constraint(d4)
+        ct.check_obj_in_active_tree(self, cons['ub'])
+        assertExpressionsEqual(self, cons['ub'].expr, d4 <= m.d1.binary_indicator_var)
 
     @unittest.skipIf(not linear_solvers, "No linear solver available")
     def test_solve_nested_model(self):
         # This is really a test that our variable references have all been moved
         # up correctly.
         m = models.makeNestedDisjunctions_NestedDisjuncts()
-
+        m.LocalVars = Suffix(direction=Suffix.LOCAL)
+        m.LocalVars[m.d1] = [
+            m.d1.binary_indicator_var,
+            m.d1.d3.binary_indicator_var,
+            m.d1.d4.binary_indicator_var,
+        ]
         hull = TransformationFactory('gdp.hull')
         m_hull = hull.create_using(m)
 
@@ -1722,10 +1778,10 @@ def test_disaggregated_vars_are_set_to_0_correctly(self):
         hull.apply_to(m)
 
         # this should be a feasible integer solution
-        m.d1.indicator_var.fix(0)
-        m.d2.indicator_var.fix(1)
-        m.d3.indicator_var.fix(0)
-        m.d4.indicator_var.fix(0)
+        m.d1.indicator_var.fix(False)
+        m.d2.indicator_var.fix(True)
+        m.d3.indicator_var.fix(False)
+        m.d4.indicator_var.fix(False)
 
         results = SolverFactory(linear_solvers[0]).solve(m)
         self.assertEqual(
@@ -1739,10 +1795,10 @@ def test_disaggregated_vars_are_set_to_0_correctly(self):
         self.assertEqual(value(hull.get_disaggregated_var(m.x, m.d4)), 0)
 
         # and what if one of the inner disjuncts is true?
-        m.d1.indicator_var.fix(1)
-        m.d2.indicator_var.fix(0)
-        m.d3.indicator_var.fix(1)
-        m.d4.indicator_var.fix(0)
+        m.d1.indicator_var.fix(True)
+        m.d2.indicator_var.fix(False)
+        m.d3.indicator_var.fix(True)
+        m.d4.indicator_var.fix(False)
 
         results = SolverFactory(linear_solvers[0]).solve(m)
         self.assertEqual(
@@ -1787,6 +1843,11 @@ def d_r(e):
                 e.c1 = Constraint(expr=e.lambdas[1] + e.lambdas[2] == 1)
                 e.c2 = Constraint(expr=m.x == 2 * e.lambdas[1] + 3 * e.lambdas[2])
 
+            d.LocalVars = Suffix(direction=Suffix.LOCAL)
+            d.LocalVars[d] = [
+                d.d_l.indicator_var.get_associated_binary(),
+                d.d_r.indicator_var.get_associated_binary(),
+            ]
             d.inner_disj = Disjunction(expr=[d.d_l, d.d_r])
 
         m.disj = Disjunction(expr=[m.d_l, m.d_r])
@@ -1809,28 +1870,159 @@ def d_r(e):
             cons = hull.get_transformed_constraints(d.c1)
             self.assertEqual(len(cons), 1)
             convex_combo = cons[0]
+            convex_combo_expr = self.simplify_cons(convex_combo)
             assertExpressionsEqual(
                 self,
-                convex_combo.expr,
-                lambda1 + lambda2 - (1 - d.indicator_var.get_associated_binary()) * 0.0
-                == d.indicator_var.get_associated_binary(),
+                convex_combo_expr,
+                lambda1 + lambda2 - d.indicator_var.get_associated_binary() == 0.0,
             )
             cons = hull.get_transformed_constraints(d.c2)
             self.assertEqual(len(cons), 1)
             get_x = cons[0]
+            get_x_expr = self.simplify_cons(get_x)
             assertExpressionsEqual(
-                self,
-                get_x.expr,
-                x
-                - (2 * lambda1 + 3 * lambda2)
-                - (1 - d.indicator_var.get_associated_binary()) * 0.0
-                == 0.0 * d.indicator_var.get_associated_binary(),
+                self, get_x_expr, x - 2 * lambda1 - 3 * lambda2 == 0.0
             )
 
         cons = hull.get_disaggregation_constraint(m.x, m.disj)
         assertExpressionsEqual(self, cons.expr, m.x == x1 + x2)
         cons = hull.get_disaggregation_constraint(m.x, m.d_r.inner_disj)
-        assertExpressionsEqual(self, cons.expr, x2 == x3 + x4)
+        cons_expr = self.simplify_cons(cons)
+        assertExpressionsEqual(self, cons_expr, x2 - x3 - x4 == 0.0)
+
+    def test_nested_with_var_that_does_not_appear_in_every_disjunct(self):
+        m = ConcreteModel()
+        m.x = Var(bounds=(0, 10))
+        m.y = Var(bounds=(-4, 5))
+        m.parent1 = Disjunct()
+        m.parent2 = Disjunct()
+        m.parent2.c = Constraint(expr=m.x == 0)
+        m.parent_disjunction = Disjunction(expr=[m.parent1, m.parent2])
+        m.child1 = Disjunct()
+        m.child1.c = Constraint(expr=m.x <= 8)
+        m.child2 = Disjunct()
+        m.child2.c = Constraint(expr=m.x + m.y <= 3)
+        m.child3 = Disjunct()
+        m.child3.c = Constraint(expr=m.x <= 7)
+        m.parent1.disjunction = Disjunction(expr=[m.child1, m.child2, m.child3])
+
+        hull = TransformationFactory('gdp.hull')
+        hull.apply_to(m)
+
+        y_c2 = hull.get_disaggregated_var(m.y, m.child2)
+        self.assertEqual(y_c2.bounds, (-4, 5))
+        other_y = hull.get_disaggregated_var(m.y, m.child1)
+        self.assertEqual(other_y.bounds, (-4, 5))
+        other_other_y = hull.get_disaggregated_var(m.y, m.child3)
+        self.assertIs(other_y, other_other_y)
+        y_p1 = hull.get_disaggregated_var(m.y, m.parent1)
+        self.assertEqual(y_p1.bounds, (-4, 5))
+        y_p2 = hull.get_disaggregated_var(m.y, m.parent2)
+        self.assertEqual(y_p2.bounds, (-4, 5))
+
+        y_cons = hull.get_disaggregation_constraint(m.y, m.parent1.disjunction)
+        # check that the disaggregated ys in the nested just sum to the original
+        y_cons_expr = self.simplify_cons(y_cons)
+        assertExpressionsEqual(self, y_cons_expr, y_p1 - other_y - y_c2 == 0.0)
+        y_cons = hull.get_disaggregation_constraint(m.y, m.parent_disjunction)
+        y_cons_expr = self.simplify_cons(y_cons)
+        assertExpressionsEqual(self, y_cons_expr, m.y - y_p2 - y_p1 == 0.0)
+
+        x_c1 = hull.get_disaggregated_var(m.x, m.child1)
+        x_c2 = hull.get_disaggregated_var(m.x, m.child2)
+        x_c3 = hull.get_disaggregated_var(m.x, m.child3)
+        x_p1 = hull.get_disaggregated_var(m.x, m.parent1)
+        x_p2 = hull.get_disaggregated_var(m.x, m.parent2)
+        x_cons_parent = hull.get_disaggregation_constraint(m.x, m.parent_disjunction)
+        assertExpressionsEqual(self, x_cons_parent.expr, m.x == x_p1 + x_p2)
+        x_cons_child = hull.get_disaggregation_constraint(m.x, m.parent1.disjunction)
+        x_cons_child_expr = self.simplify_cons(x_cons_child)
+        assertExpressionsEqual(
+            self, x_cons_child_expr, x_p1 - x_c1 - x_c2 - x_c3 == 0.0
+        )
+
+    def simplify_cons(self, cons):
+        visitor = LinearRepnVisitor({}, {}, {}, None)
+        lb = cons.lower
+        ub = cons.upper
+        self.assertEqual(cons.lb, cons.ub)
+        repn = visitor.walk_expression(cons.body)
+        self.assertIsNone(repn.nonlinear)
+        return repn.to_expression(visitor) == lb
+
+    def simplify_leq_cons(self, cons):
+        visitor = LinearRepnVisitor({}, {}, {}, None)
+        self.assertIsNone(cons.lower)
+        ub = cons.upper
+        repn = visitor.walk_expression(cons.body)
+        self.assertIsNone(repn.nonlinear)
+        return repn.to_expression(visitor) <= ub
+
+    def test_nested_with_var_that_skips_a_level(self):
+        m = ConcreteModel()
+
+        m.x = Var(bounds=(-2, 9))
+        m.y = Var(bounds=(-3, 8))
+
+        m.y1 = Disjunct()
+        m.y1.c1 = Constraint(expr=m.x >= 4)
+        m.y1.z1 = Disjunct()
+        m.y1.z1.c1 = Constraint(expr=m.y == 2)
+        m.y1.z1.w1 = Disjunct()
+        m.y1.z1.w1.c1 = Constraint(expr=m.x == 3)
+        m.y1.z1.w2 = Disjunct()
+        m.y1.z1.w2.c1 = Constraint(expr=m.x >= 1)
+        m.y1.z1.disjunction = Disjunction(expr=[m.y1.z1.w1, m.y1.z1.w2])
+        m.y1.z2 = Disjunct()
+        m.y1.z2.c1 = Constraint(expr=m.y == 1)
+        m.y1.disjunction = Disjunction(expr=[m.y1.z1, m.y1.z2])
+        m.y2 = Disjunct()
+        m.y2.c1 = Constraint(expr=m.x == 4)
+        m.disjunction = Disjunction(expr=[m.y1, m.y2])
+
+        hull = TransformationFactory('gdp.hull')
+        hull.apply_to(m)
+
+        x_y1 = hull.get_disaggregated_var(m.x, m.y1)
+        x_y2 = hull.get_disaggregated_var(m.x, m.y2)
+        x_z1 = hull.get_disaggregated_var(m.x, m.y1.z1)
+        x_z2 = hull.get_disaggregated_var(m.x, m.y1.z2)
+        x_w1 = hull.get_disaggregated_var(m.x, m.y1.z1.w1)
+        x_w2 = hull.get_disaggregated_var(m.x, m.y1.z1.w2)
+
+        y_z1 = hull.get_disaggregated_var(m.y, m.y1.z1)
+        y_z2 = hull.get_disaggregated_var(m.y, m.y1.z2)
+        y_y1 = hull.get_disaggregated_var(m.y, m.y1)
+        y_y2 = hull.get_disaggregated_var(m.y, m.y2)
+
+        cons = hull.get_disaggregation_constraint(m.x, m.y1.z1.disjunction)
+        self.assertTrue(cons.active)
+        cons_expr = self.simplify_cons(cons)
+        assertExpressionsEqual(self, cons_expr, x_z1 - x_w1 - x_w2 == 0.0)
+        cons = hull.get_disaggregation_constraint(m.x, m.y1.disjunction)
+        self.assertTrue(cons.active)
+        cons_expr = self.simplify_cons(cons)
+        assertExpressionsEqual(self, cons_expr, x_y1 - x_z2 - x_z1 == 0.0)
+        cons = hull.get_disaggregation_constraint(m.x, m.disjunction)
+        self.assertTrue(cons.active)
+        cons_expr = self.simplify_cons(cons)
+        assertExpressionsEqual(self, cons_expr, m.x - x_y1 - x_y2 == 0.0)
+        cons = hull.get_disaggregation_constraint(
+            m.y, m.y1.z1.disjunction, raise_exception=False
+        )
+        self.assertIsNone(cons)
+        cons = hull.get_disaggregation_constraint(m.y, m.y1.disjunction)
+        self.assertTrue(cons.active)
+        cons_expr = self.simplify_cons(cons)
+        assertExpressionsEqual(self, cons_expr, y_y1 - y_z1 - y_z2 == 0.0)
+        cons = hull.get_disaggregation_constraint(m.y, m.disjunction)
+        self.assertTrue(cons.active)
+        cons_expr = self.simplify_cons(cons)
+        assertExpressionsEqual(self, cons_expr, m.y - y_y2 - y_y1 == 0.0)
+
+    @unittest.skipUnless(gurobi_available, "Gurobi is not available")
+    def test_do_not_assume_nested_indicators_local(self):
+        ct.check_do_not_assume_nested_indicators_local(self, 'gdp.hull')
 
 
 class TestSpecialCases(unittest.TestCase):
@@ -2100,27 +2292,19 @@ def test_mapping_method_errors(self):
         hull = TransformationFactory('gdp.hull')
         hull.apply_to(m)
 
-        log = StringIO()
-        with LoggingIntercept(log, 'pyomo.gdp.hull', logging.ERROR):
-            self.assertRaisesRegex(
-                AttributeError,
-                "'NoneType' object has no attribute 'parent_block'",
-                hull.get_var_bounds_constraint,
-                m.w,
-            )
-        self.assertRegex(
-            log.getvalue(),
+        with self.assertRaisesRegex(
+            GDP_Error,
             ".*Either 'w' is not a disaggregated variable, "
             "or the disjunction that disaggregates it has "
             "not been properly transformed.",
-        )
+        ):
+            hull.get_var_bounds_constraint(m.w)
 
         log = StringIO()
         with LoggingIntercept(log, 'pyomo.gdp.hull', logging.ERROR):
             self.assertRaisesRegex(
                 KeyError,
-                r".*_pyomo_gdp_hull_reformulation.relaxedDisjuncts\[1\]."
-                r"disaggregatedVars.w",
+                r".*disjunction",
                 hull.get_disaggregation_constraint,
                 m.d[1].transformation_block.disaggregatedVars.w,
                 m.disjunction,
@@ -2134,36 +2318,22 @@ def test_mapping_method_errors(self):
             r"Disjunction 'disjunction'",
         )
 
-        log = StringIO()
-        with LoggingIntercept(log, 'pyomo.gdp.hull', logging.ERROR):
-            self.assertRaisesRegex(
-                AttributeError,
-                "'NoneType' object has no attribute 'parent_block'",
-                hull.get_src_var,
-                m.w,
-            )
-        self.assertRegex(
-            log.getvalue(), ".*'w' does not appear to be a disaggregated variable"
-        )
+        with self.assertRaisesRegex(
+            GDP_Error, ".*'w' does not appear to be a disaggregated variable"
+        ):
+            hull.get_src_var(m.w)
 
-        log = StringIO()
-        with LoggingIntercept(log, 'pyomo.gdp.hull', logging.ERROR):
-            self.assertRaisesRegex(
-                KeyError,
-                r".*_pyomo_gdp_hull_reformulation.relaxedDisjuncts\[1\]."
-                r"disaggregatedVars.w",
-                hull.get_disaggregated_var,
-                m.d[1].transformation_block.disaggregatedVars.w,
-                m.d[1],
-            )
-        self.assertRegex(
-            log.getvalue(),
+        with self.assertRaisesRegex(
+            GDP_Error,
             r".*It does not appear "
             r"'_pyomo_gdp_hull_reformulation."
             r"relaxedDisjuncts\[1\].disaggregatedVars.w' "
             r"is a variable that appears in disjunct "
             r"'d\[1\]'",
-        )
+        ):
+            hull.get_disaggregated_var(
+                m.d[1].transformation_block.disaggregatedVars.w, m.d[1]
+            )
 
         m.random_disjunction = Disjunction(expr=[m.w == 2, m.w >= 7])
         self.assertRaisesRegex(
@@ -2398,12 +2568,12 @@ def OneCentroidPerPt(m, i):
         TransformationFactory('gdp.hull').apply_to(m)
 
         # fix an optimal solution
-        m.AssignPoint[1, 1].indicator_var.fix(1)
-        m.AssignPoint[1, 2].indicator_var.fix(0)
-        m.AssignPoint[2, 1].indicator_var.fix(0)
-        m.AssignPoint[2, 2].indicator_var.fix(1)
-        m.AssignPoint[3, 1].indicator_var.fix(1)
-        m.AssignPoint[3, 2].indicator_var.fix(0)
+        m.AssignPoint[1, 1].indicator_var.fix(True)
+        m.AssignPoint[1, 2].indicator_var.fix(False)
+        m.AssignPoint[2, 1].indicator_var.fix(False)
+        m.AssignPoint[2, 2].indicator_var.fix(True)
+        m.AssignPoint[3, 1].indicator_var.fix(True)
+        m.AssignPoint[3, 2].indicator_var.fix(False)
 
         m.cluster_center[1].fix(0.3059)
         m.cluster_center[2].fix(0.8043)
diff --git a/pyomo/gdp/tests/test_mbigm.py b/pyomo/gdp/tests/test_mbigm.py
index f067e1da5af..14a23160574 100644
--- a/pyomo/gdp/tests/test_mbigm.py
+++ b/pyomo/gdp/tests/test_mbigm.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -10,6 +10,7 @@
 #  ___________________________________________________________________________
 
 from io import StringIO
+import logging
 from os.path import join, normpath
 import pickle
 
@@ -50,7 +51,25 @@
 exdir = normpath(join(PYOMO_ROOT_DIR, 'examples', 'gdp'))
 
 
-class LinearModelDecisionTreeExample(unittest.TestCase):
+class CommonTests(unittest.TestCase):
+    def check_pretty_bound_constraints(self, cons, var, bounds, lb):
+        self.assertEqual(value(cons.upper), 0)
+        self.assertIsNone(cons.lower)
+        repn = generate_standard_repn(cons.body)
+        self.assertTrue(repn.is_linear())
+        self.assertEqual(len(repn.linear_vars), len(bounds) + 1)
+        self.assertEqual(repn.constant, 0)
+        if lb:
+            check_linear_coef(self, repn, var, -1)
+            for disj, bnd in bounds.items():
+                check_linear_coef(self, repn, disj.binary_indicator_var, bnd)
+        else:
+            check_linear_coef(self, repn, var, 1)
+            for disj, bnd in bounds.items():
+                check_linear_coef(self, repn, disj.binary_indicator_var, -bnd)
+
+
+class LinearModelDecisionTreeExample(CommonTests):
     def make_model(self):
         m = ConcreteModel()
         m.x1 = Var(bounds=(-10, 10))
@@ -333,6 +352,43 @@ def test_transformed_constraints_correct_Ms_specified(self):
         self.check_all_untightened_bounds_constraints(m, mbm)
         self.check_linear_func_constraints(m, mbm)
 
+    def test_local_var_suffix_ignored(self):
+        m = self.make_model()
+        m.y = Var(bounds=(2, 5))
+        m.d1.another_thing = Constraint(expr=m.y == 3)
+        m.d1.LocalVars = Suffix(direction=Suffix.LOCAL)
+        m.d1.LocalVars[m.d1] = m.y
+
+        mbigm = TransformationFactory('gdp.mbigm')
+        mbigm.apply_to(
+            m, reduce_bound_constraints=True, only_mbigm_bound_constraints=True
+        )
+
+        cons = mbigm.get_transformed_constraints(m.d1.x1_bounds)
+        self.check_pretty_bound_constraints(
+            cons[0], m.x1, {m.d1: 0.5, m.d2: 0.65, m.d3: 2}, lb=True
+        )
+        self.check_pretty_bound_constraints(
+            cons[1], m.x1, {m.d1: 2, m.d2: 3, m.d3: 10}, lb=False
+        )
+
+        cons = mbigm.get_transformed_constraints(m.d1.x2_bounds)
+        self.check_pretty_bound_constraints(
+            cons[0], m.x2, {m.d1: 0.75, m.d2: 3, m.d3: 0.55}, lb=True
+        )
+        self.check_pretty_bound_constraints(
+            cons[1], m.x2, {m.d1: 3, m.d2: 10, m.d3: 1}, lb=False
+        )
+
+        cons = mbigm.get_transformed_constraints(m.d1.another_thing)
+        self.assertEqual(len(cons), 2)
+        self.check_pretty_bound_constraints(
+            cons[0], m.y, {m.d1: 3, m.d2: 2, m.d3: 2}, lb=True
+        )
+        self.check_pretty_bound_constraints(
+            cons[1], m.y, {m.d1: 3, m.d2: 5, m.d3: 5}, lb=False
+        )
+
     def test_pickle_transformed_model(self):
         m = self.make_model()
         TransformationFactory('gdp.mbigm').apply_to(m, bigM=self.get_Ms(m))
@@ -381,22 +437,6 @@ def test_algebraic_constraints(self):
         check_linear_coef(self, repn, m.d3.binary_indicator_var, 1)
         check_obj_in_active_tree(self, xor)
 
-    def check_pretty_bound_constraints(self, cons, var, bounds, lb):
-        self.assertEqual(value(cons.upper), 0)
-        self.assertIsNone(cons.lower)
-        repn = generate_standard_repn(cons.body)
-        self.assertTrue(repn.is_linear())
-        self.assertEqual(len(repn.linear_vars), len(bounds) + 1)
-        self.assertEqual(repn.constant, 0)
-        if lb:
-            check_linear_coef(self, repn, var, -1)
-            for disj, bnd in bounds.items():
-                check_linear_coef(self, repn, disj.binary_indicator_var, bnd)
-        else:
-            check_linear_coef(self, repn, var, 1)
-            for disj, bnd in bounds.items():
-                check_linear_coef(self, repn, disj.binary_indicator_var, -bnd)
-
     def test_bounds_constraints_correct(self):
         m = self.make_model()
 
@@ -877,6 +917,25 @@ def test_declare_disjuncts_in_disjunction_rule(self):
         check_nested_disjuncts_in_flat_gdp(self, 'bigm')
 
 
+class IndexedDisjunctiveConstraints(CommonTests):
+    def test_empty_constraint_container_on_Disjunct(self):
+        m = ConcreteModel()
+        m.d = Disjunct()
+        m.e = Disjunct()
+        m.d.c = Constraint(['s', 'i', 'l', 'L', 'y'])
+        m.x = Var(bounds=(2, 3))
+        m.e.c = Constraint(expr=m.x == 2.7)
+        m.disjunction = Disjunction(expr=[m.d, m.e])
+
+        mbm = TransformationFactory('gdp.mbigm')
+        mbm.apply_to(m)
+
+        cons = mbm.get_transformed_constraints(m.e.c)
+        self.assertEqual(len(cons), 2)
+        self.check_pretty_bound_constraints(cons[0], m.x, {m.d: 2, m.e: 2.7}, lb=True)
+        self.check_pretty_bound_constraints(cons[1], m.x, {m.d: 3, m.e: 2.7}, lb=False)
+
+
 @unittest.skipUnless(gurobi_available, "Gurobi is not available")
 class IndexedDisjunction(unittest.TestCase):
     def test_two_term_indexed_disjunction(self):
@@ -930,3 +989,113 @@ def test_two_term_indexed_disjunction(self):
         self.assertEqual(len(cons_again), 2)
         self.assertIs(cons_again[0], cons[0])
         self.assertIs(cons_again[1], cons[1])
+
+
+class EdgeCases(unittest.TestCase):
+    def make_infeasible_disjunct_model(self):
+        m = ConcreteModel()
+        m.x = Var(bounds=(1, 12))
+        m.y = Var(bounds=(19, 22))
+        m.disjunction = Disjunction(
+            expr=[
+                [m.x >= 3 + m.y, m.y == 19.75],  # infeasible given bounds
+                [m.y >= 21 + m.x],  # unique solution
+                [m.x == m.y - 9],  # x in interval [10, 12]
+            ]
+        )
+        return m
+
+    @unittest.skipUnless(gurobi_available, "Gurobi is not available")
+    def test_calculate_Ms_infeasible_Disjunct(self):
+        m = self.make_infeasible_disjunct_model()
+        out = StringIO()
+        mbm = TransformationFactory('gdp.mbigm')
+        with LoggingIntercept(out, 'pyomo.gdp.mbigm', logging.DEBUG):
+            mbm.apply_to(m, reduce_bound_constraints=False)
+
+        # We mentioned the infeasibility at the DEBUG level
+        self.assertIn(
+            r"Disjunct 'disjunction_disjuncts[0]' is infeasible, deactivating",
+            out.getvalue().strip(),
+        )
+
+        # We just fixed the infeasible disjunct to False
+        self.assertFalse(m.disjunction.disjuncts[0].active)
+        self.assertTrue(m.disjunction.disjuncts[0].indicator_var.fixed)
+        self.assertFalse(value(m.disjunction.disjuncts[0].indicator_var))
+
+        # We didn't actually transform the infeasible disjunct
+        self.assertIsNone(m.disjunction.disjuncts[0].transformation_block)
+
+        # the remaining constraints are transformed correctly.
+        cons = mbm.get_transformed_constraints(m.disjunction.disjuncts[1].constraint[1])
+        self.assertEqual(len(cons), 1)
+        assertExpressionsEqual(
+            self,
+            cons[0].expr,
+            21 + m.x - m.y <= 12.0 * m.disjunction.disjuncts[2].binary_indicator_var,
+        )
+
+        cons = mbm.get_transformed_constraints(m.disjunction.disjuncts[2].constraint[1])
+        self.assertEqual(len(cons), 2)
+        assertExpressionsEqual(
+            self,
+            cons[0].expr,
+            -12.0 * m.disjunction_disjuncts[1].binary_indicator_var <= m.x - (m.y - 9),
+        )
+        assertExpressionsEqual(
+            self,
+            cons[1].expr,
+            m.x - (m.y - 9) <= -12.0 * m.disjunction_disjuncts[1].binary_indicator_var,
+        )
+
+    @unittest.skipUnless(
+        SolverFactory('ipopt').available(exception_flag=False), "Ipopt is not available"
+    )
+    def test_calculate_Ms_infeasible_Disjunct_local_solver(self):
+        m = self.make_infeasible_disjunct_model()
+        with self.assertRaisesRegex(
+            GDP_Error,
+            r"Unsuccessful solve to calculate M value to "
+            r"relax constraint 'disjunction_disjuncts\[1\].constraint\[1\]' "
+            r"on Disjunct 'disjunction_disjuncts\[1\]' when "
+            r"Disjunct 'disjunction_disjuncts\[0\]' is selected.",
+        ):
+            TransformationFactory('gdp.mbigm').apply_to(
+                m, solver=SolverFactory('ipopt'), reduce_bound_constraints=False
+            )
+
+    @unittest.skipUnless(gurobi_available, "Gurobi is not available")
+    def test_politely_ignore_BigM_Suffix(self):
+        m = self.make_infeasible_disjunct_model()
+        m.disjunction.disjuncts[0].deactivate()
+        m.disjunction.disjuncts[1].BigM = Suffix(direction=Suffix.LOCAL)
+        out = StringIO()
+        with LoggingIntercept(out, 'pyomo.gdp.mbigm', logging.DEBUG):
+            TransformationFactory('gdp.mbigm').apply_to(
+                m, reduce_bound_constraints=False
+            )
+        warnings = out.getvalue()
+        self.assertIn(
+            r"Found active 'BigM' Suffix on 'disjunction_disjuncts[1]'. "
+            r"The multiple bigM transformation does not currently "
+            r"support specifying M's with Suffixes and is ignoring "
+            r"this Suffix.",
+            warnings,
+        )
+
+    @unittest.skipUnless(gurobi_available, "Gurobi is not available")
+    def test_complain_for_unrecognized_Suffix(self):
+        m = self.make_infeasible_disjunct_model()
+        m.disjunction.disjuncts[0].deactivate()
+        m.disjunction.disjuncts[1].HiThere = Suffix(direction=Suffix.LOCAL)
+        out = StringIO()
+        with self.assertRaisesRegex(
+            GDP_Error,
+            r"Found active Suffix 'disjunction_disjuncts\[1\].HiThere' "
+            r"on Disjunct 'disjunction_disjuncts\[1\]'. The multiple bigM "
+            r"transformation does not support this Suffix.",
+        ):
+            TransformationFactory('gdp.mbigm').apply_to(
+                m, reduce_bound_constraints=False
+            )
diff --git a/pyomo/gdp/tests/test_partition_disjuncts.py b/pyomo/gdp/tests/test_partition_disjuncts.py
index b050bc5e653..dc5ae9f70ce 100644
--- a/pyomo/gdp/tests/test_partition_disjuncts.py
+++ b/pyomo/gdp/tests/test_partition_disjuncts.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/gdp/tests/test_reclassify.py b/pyomo/gdp/tests/test_reclassify.py
index fd98f8f0954..223c28c5c7a 100644
--- a/pyomo/gdp/tests/test_reclassify.py
+++ b/pyomo/gdp/tests/test_reclassify.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # -*- coding: UTF-8 -*-
 """Tests disjunct reclassifier transformation."""
 import pyomo.common.unittest as unittest
diff --git a/pyomo/gdp/tests/test_transform_current_disjunctive_state.py b/pyomo/gdp/tests/test_transform_current_disjunctive_state.py
index d257c3db8fb..54d80c910e5 100644
--- a/pyomo/gdp/tests/test_transform_current_disjunctive_state.py
+++ b/pyomo/gdp/tests/test_transform_current_disjunctive_state.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/gdp/tests/test_util.py b/pyomo/gdp/tests/test_util.py
index 90c63717b81..fa8e953f9f7 100644
--- a/pyomo/gdp/tests/test_util.py
+++ b/pyomo/gdp/tests/test_util.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -13,7 +13,7 @@
 
 from pyomo.core import ConcreteModel, Var, Expression, Block, RangeSet, Any
 import pyomo.core.expr as EXPR
-from pyomo.core.base.expression import _ExpressionData
+from pyomo.core.base.expression import NamedExpressionData
 from pyomo.gdp.util import (
     clone_without_expression_components,
     is_child_of,
@@ -40,7 +40,7 @@ def test_clone_without_expression_components(self):
         test = clone_without_expression_components(base, {})
         self.assertIsNot(base, test)
         self.assertEqual(base(), test())
-        self.assertIsInstance(base, _ExpressionData)
+        self.assertIsInstance(base, NamedExpressionData)
         self.assertIsInstance(test, EXPR.SumExpression)
         test = clone_without_expression_components(base, {id(m.x): m.y})
         self.assertEqual(3**2 + 3 - 1, test())
@@ -51,7 +51,7 @@ def test_clone_without_expression_components(self):
         self.assertEqual(base(), test())
         self.assertIsInstance(base, EXPR.SumExpression)
         self.assertIsInstance(test, EXPR.SumExpression)
-        self.assertIsInstance(base.arg(0), _ExpressionData)
+        self.assertIsInstance(base.arg(0), NamedExpressionData)
         self.assertIsInstance(test.arg(0), EXPR.SumExpression)
         test = clone_without_expression_components(base, {id(m.x): m.y})
         self.assertEqual(3**2 + 3 - 1 + 3, test())
diff --git a/pyomo/gdp/transformed_disjunct.py b/pyomo/gdp/transformed_disjunct.py
index 400f77a31f6..287d5ed1652 100644
--- a/pyomo/gdp/transformed_disjunct.py
+++ b/pyomo/gdp/transformed_disjunct.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -10,11 +10,11 @@
 #  ___________________________________________________________________________
 
 from pyomo.common.autoslots import AutoSlots
-from pyomo.core.base.block import _BlockData, IndexedBlock
+from pyomo.core.base.block import BlockData, IndexedBlock
 from pyomo.core.base.global_set import UnindexedComponent_index, UnindexedComponent_set
 
 
-class _TransformedDisjunctData(_BlockData):
+class _TransformedDisjunctData(BlockData):
     __slots__ = ('_src_disjunct',)
     __autoslot_mappers__ = {'_src_disjunct': AutoSlots.weakref_mapper}
 
@@ -23,7 +23,7 @@ def src_disjunct(self):
         return None if self._src_disjunct is None else self._src_disjunct()
 
     def __init__(self, component):
-        _BlockData.__init__(self, component)
+        BlockData.__init__(self, component)
         # pointer to the Disjunct whose transformation block this is.
         self._src_disjunct = None
 
diff --git a/pyomo/gdp/util.py b/pyomo/gdp/util.py
index b460a3d691c..2fe8e9e1dee 100644
--- a/pyomo/gdp/util.py
+++ b/pyomo/gdp/util.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -10,10 +10,9 @@
 #  ___________________________________________________________________________
 
 from pyomo.gdp import GDP_Error, Disjunction
-from pyomo.gdp.disjunct import _DisjunctData, Disjunct
+from pyomo.gdp.disjunct import DisjunctData, Disjunct
 
 import pyomo.core.expr as EXPR
-from pyomo.core.base.component import _ComponentBase
 from pyomo.core import (
     Block,
     Suffix,
@@ -22,7 +21,7 @@
     LogicalConstraint,
     value,
 )
-from pyomo.core.base.block import _BlockData
+from pyomo.core.base.block import BlockData
 from pyomo.common.collections import ComponentMap, ComponentSet, OrderedSet
 from pyomo.opt import TerminationCondition, SolverStatus
 
@@ -144,13 +143,13 @@ def parent(self, u):
         Arg:
             u : A node in the tree
         """
+        if u in self._parent:
+            return self._parent[u]
         if u not in self._vertices:
             raise ValueError(
                 "'%s' is not a vertex in the GDP tree. Cannot "
                 "retrieve its parent." % u
             )
-        if u in self._parent:
-            return self._parent[u]
         else:
             return None
 
@@ -169,7 +168,10 @@ def parent_disjunct(self, u):
         Arg:
             u : A node in the forest
         """
-        return self.parent(self.parent(u))
+        if u.ctype is Disjunct:
+            return self.parent(self.parent(u))
+        else:
+            return self.parent(u)
 
     def root_disjunct(self, u):
         """Returns the highest parent Disjunct in the hierarchy, or None if
@@ -183,7 +185,7 @@ def root_disjunct(self, u):
         while True:
             if parent is None:
                 return rootmost_disjunct
-            if isinstance(parent, _DisjunctData) or parent.ctype is Disjunct:
+            if parent.ctype is Disjunct:
                 rootmost_disjunct = parent
             parent = self.parent(parent)
 
@@ -243,7 +245,7 @@ def leaves(self):
     @property
     def disjunct_nodes(self):
         for v in self._vertices:
-            if isinstance(v, _DisjunctData) or v.ctype is Disjunct:
+            if v.ctype is Disjunct:
                 yield v
 
 
@@ -327,7 +329,7 @@ def get_gdp_tree(targets, instance, knownBlocks=None):
                 "Target '%s' is not a component on instance "
                 "'%s'!" % (t.name, instance.name)
             )
-        if t.ctype is Block or isinstance(t, _BlockData):
+        if t.ctype is Block or isinstance(t, BlockData):
             _blocks = t.values() if t.is_indexed() else (t,)
             for block in _blocks:
                 if not block.active:
@@ -384,7 +386,7 @@ def is_child_of(parent, child, knownBlocks=None):
     if knownBlocks is None:
         knownBlocks = {}
     tmp = set()
-    node = child if isinstance(child, (Block, _BlockData)) else child.parent_block()
+    node = child if isinstance(child, (Block, BlockData)) else child.parent_block()
     while True:
         known = knownBlocks.get(node)
         if known:
@@ -449,7 +451,7 @@ def get_src_disjunct(transBlock):
 
     Parameters
     ----------
-    transBlock: _BlockData which is in the relaxedDisjuncts IndexedBlock
+    transBlock: BlockData which is in the relaxedDisjuncts IndexedBlock
                 on a transformation block.
     """
     if (
@@ -474,22 +476,23 @@ def get_src_constraint(transformedConstraint):
     a transformation block
     """
     transBlock = transformedConstraint.parent_block()
+    src_constraints = transBlock.private_data('pyomo.gdp').src_constraint
     # This should be our block, so if it's not, the user messed up and gave
     # us the wrong thing. If they happen to also have a _constraintMap then
     # the world is really against us.
-    if not hasattr(transBlock, "_constraintMap"):
+    if transformedConstraint not in src_constraints:
         raise GDP_Error(
             "Constraint '%s' is not a transformed constraint"
             % transformedConstraint.name
         )
     # if something goes wrong here, it's a bug in the mappings.
-    return transBlock._constraintMap['srcConstraints'][transformedConstraint]
+    return src_constraints[transformedConstraint]
 
 
 def _find_parent_disjunct(constraint):
     # traverse up until we find the disjunct this constraint lives on
     parent_disjunct = constraint.parent_block()
-    while not isinstance(parent_disjunct, _DisjunctData):
+    while not isinstance(parent_disjunct, DisjunctData):
         if parent_disjunct is None:
             raise GDP_Error(
                 "Constraint '%s' is not on a disjunct and so was not "
@@ -521,24 +524,28 @@ def get_transformed_constraints(srcConstraint):
 
     Parameters
     ----------
-    srcConstraint: ScalarConstraint or _ConstraintData, which must be in
+    srcConstraint: ScalarConstraint or ConstraintData, which must be in
     the subtree of a transformed Disjunct
     """
     if srcConstraint.is_indexed():
         raise GDP_Error(
             "Argument to get_transformed_constraint should be "
-            "a ScalarConstraint or _ConstraintData. (If you "
+            "a ScalarConstraint or ConstraintData. (If you "
             "want the container for all transformed constraints "
             "from an IndexedDisjunction, this is the parent "
             "component of a transformed constraint originating "
-            "from any of its _ComponentDatas.)"
+            "from any of its ComponentDatas.)"
         )
     transBlock = _get_constraint_transBlock(srcConstraint)
-    try:
-        return transBlock._constraintMap['transformedConstraints'][srcConstraint]
-    except:
-        logger.error("Constraint '%s' has not been transformed." % srcConstraint.name)
-        raise
+    transformed_constraints = transBlock.private_data(
+        'pyomo.gdp'
+    ).transformed_constraints
+    if srcConstraint in transformed_constraints:
+        return transformed_constraints[srcConstraint]
+    else:
+        raise GDP_Error(
+            "Constraint '%s' has not been transformed." % srcConstraint.name
+        )
 
 
 def _warn_for_active_disjunct(innerdisjunct, outerdisjunct):
diff --git a/pyomo/kernel/__init__.py b/pyomo/kernel/__init__.py
index 6ecea6343cd..289fe83f0e4 100644
--- a/pyomo/kernel/__init__.py
+++ b/pyomo/kernel/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/kernel/util.py b/pyomo/kernel/util.py
index 5fba6a2c2d9..bdfd0939537 100644
--- a/pyomo/kernel/util.py
+++ b/pyomo/kernel/util.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/mpec/__init__.py b/pyomo/mpec/__init__.py
index 3989fe07b8e..a98ab94dc87 100644
--- a/pyomo/mpec/__init__.py
+++ b/pyomo/mpec/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/mpec/complementarity.py b/pyomo/mpec/complementarity.py
index df991ce9686..26968ef9fca 100644
--- a/pyomo/mpec/complementarity.py
+++ b/pyomo/mpec/complementarity.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -19,7 +19,7 @@
 from pyomo.core import Constraint, Var, Block, Set
 from pyomo.core.base.component import ModelComponentFactory
 from pyomo.core.base.global_set import UnindexedComponent_index
-from pyomo.core.base.block import _BlockData
+from pyomo.core.base.block import BlockData
 from pyomo.core.base.disable_methods import disable_methods
 from pyomo.core.base.initializer import (
     Initializer,
@@ -43,7 +43,7 @@ def complements(a, b):
     return ComplementarityTuple(a, b)
 
 
-class _ComplementarityData(_BlockData):
+class ComplementarityData(BlockData):
     def _canonical_expression(self, e):
         # Note: as the complimentarity component maintains references to
         # the original expression (e), it is NOT safe or valid to bypass
@@ -179,9 +179,14 @@ def set_value(self, cc):
             )
 
 
+class _ComplementarityData(metaclass=RenamedClass):
+    __renamed__new_class__ = ComplementarityData
+    __renamed__version__ = '6.7.2'
+
+
 @ModelComponentFactory.register("Complementarity conditions.")
 class Complementarity(Block):
-    _ComponentDataClass = _ComplementarityData
+    _ComponentDataClass = ComplementarityData
 
     def __new__(cls, *args, **kwds):
         if cls != Complementarity:
@@ -298,9 +303,9 @@ def _conditional_block_printer(ostream, idx, data):
         )
 
 
-class ScalarComplementarity(_ComplementarityData, Complementarity):
+class ScalarComplementarity(ComplementarityData, Complementarity):
     def __init__(self, *args, **kwds):
-        _ComplementarityData.__init__(self, self)
+        ComplementarityData.__init__(self, self)
         Complementarity.__init__(self, *args, **kwds)
         self._data[None] = self
         self._index = UnindexedComponent_index
@@ -357,13 +362,18 @@ def construct(self, data=None):
         """
         Construct the expression(s) for this complementarity condition.
         """
-        if is_debug_set(logger):
-            logger.debug("Constructing complementarity list %s", self.name)
         if self._constructed:
             return
-        timer = ConstructionTimer(self)
         self._constructed = True
 
+        timer = ConstructionTimer(self)
+        if is_debug_set(logger):
+            logger.debug("Constructing complementarity list %s", self.name)
+
+        if self._anonymous_sets is not None:
+            for _set in self._anonymous_sets:
+                _set.construct()
+
         if self._init_rule is not None:
             _init = self._init_rule(self.parent_block(), ())
             for cc in iter(_init):
diff --git a/pyomo/mpec/plugins/__init__.py b/pyomo/mpec/plugins/__init__.py
index 3317e1ce829..1ff8c316e9b 100644
--- a/pyomo/mpec/plugins/__init__.py
+++ b/pyomo/mpec/plugins/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/mpec/plugins/mpec1.py b/pyomo/mpec/plugins/mpec1.py
index ad6905158c7..5935569d370 100644
--- a/pyomo/mpec/plugins/mpec1.py
+++ b/pyomo/mpec/plugins/mpec1.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/mpec/plugins/mpec2.py b/pyomo/mpec/plugins/mpec2.py
index d019424ea4b..89d6c0814b2 100644
--- a/pyomo/mpec/plugins/mpec2.py
+++ b/pyomo/mpec/plugins/mpec2.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/mpec/plugins/mpec3.py b/pyomo/mpec/plugins/mpec3.py
index d681c305a2d..1b7eb58b021 100644
--- a/pyomo/mpec/plugins/mpec3.py
+++ b/pyomo/mpec/plugins/mpec3.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/mpec/plugins/mpec4.py b/pyomo/mpec/plugins/mpec4.py
index 5b32886711a..fa3e37b16fe 100644
--- a/pyomo/mpec/plugins/mpec4.py
+++ b/pyomo/mpec/plugins/mpec4.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/mpec/plugins/pathampl.py b/pyomo/mpec/plugins/pathampl.py
index 7875251c04b..23b1b393ef3 100644
--- a/pyomo/mpec/plugins/pathampl.py
+++ b/pyomo/mpec/plugins/pathampl.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/mpec/plugins/solver1.py b/pyomo/mpec/plugins/solver1.py
index 0ac1af85522..02659844f1c 100644
--- a/pyomo/mpec/plugins/solver1.py
+++ b/pyomo/mpec/plugins/solver1.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/mpec/plugins/solver2.py b/pyomo/mpec/plugins/solver2.py
index 491c8122d2e..5f5b6922e6f 100644
--- a/pyomo/mpec/plugins/solver2.py
+++ b/pyomo/mpec/plugins/solver2.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/mpec/tests/__init__.py b/pyomo/mpec/tests/__init__.py
index c5e495e5aa3..a2a2c61779a 100644
--- a/pyomo/mpec/tests/__init__.py
+++ b/pyomo/mpec/tests/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/mpec/tests/cov2_None.txt b/pyomo/mpec/tests/cov2_None.txt
index 2f7d59572a8..c3c0baeeb9e 100644
--- a/pyomo/mpec/tests/cov2_None.txt
+++ b/pyomo/mpec/tests/cov2_None.txt
@@ -1,2 +1,2 @@
-cc : Size=0, Index=cc_index, Active=True
+cc : Size=0, Index={0, 1, 2}, Active=True
     Key : Arg0 : Arg1 : Active
diff --git a/pyomo/mpec/tests/cov2_mpec.nl.txt b/pyomo/mpec/tests/cov2_mpec.nl.txt
index a526784344b..9b7b9ed53f4 100644
--- a/pyomo/mpec/tests/cov2_mpec.nl.txt
+++ b/pyomo/mpec/tests/cov2_mpec.nl.txt
@@ -1,8 +1,3 @@
-1 Set Declarations
-    cc_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    3 : {0, 1, 2}
-
 4 Var Declarations
     x1 : Size=1, Index=None
         Key  : Lower : Value : Upper : Fixed : Stale : Domain
@@ -23,7 +18,7 @@
         None :   0.5 :   x1 :   0.5 :   True
 
 1 Block Declarations
-    cc : Size=0, Index=cc_index, Active=True
+    cc : Size=0, Index={0, 1, 2}, Active=True
         Key : Arg0 : Arg1 : Active
 
-7 Declarations: y x1 x2 x3 cc_index cc keep_var_con
+6 Declarations: y x1 x2 x3 cc keep_var_con
diff --git a/pyomo/mpec/tests/cov2_mpec.simple_disjunction.txt b/pyomo/mpec/tests/cov2_mpec.simple_disjunction.txt
index 2f7d59572a8..c3c0baeeb9e 100644
--- a/pyomo/mpec/tests/cov2_mpec.simple_disjunction.txt
+++ b/pyomo/mpec/tests/cov2_mpec.simple_disjunction.txt
@@ -1,2 +1,2 @@
-cc : Size=0, Index=cc_index, Active=True
+cc : Size=0, Index={0, 1, 2}, Active=True
     Key : Arg0 : Arg1 : Active
diff --git a/pyomo/mpec/tests/cov2_mpec.simple_nonlinear.txt b/pyomo/mpec/tests/cov2_mpec.simple_nonlinear.txt
index 2f7d59572a8..c3c0baeeb9e 100644
--- a/pyomo/mpec/tests/cov2_mpec.simple_nonlinear.txt
+++ b/pyomo/mpec/tests/cov2_mpec.simple_nonlinear.txt
@@ -1,2 +1,2 @@
-cc : Size=0, Index=cc_index, Active=True
+cc : Size=0, Index={0, 1, 2}, Active=True
     Key : Arg0 : Arg1 : Active
diff --git a/pyomo/mpec/tests/cov2_mpec.standard_form.txt b/pyomo/mpec/tests/cov2_mpec.standard_form.txt
index 2f7d59572a8..c3c0baeeb9e 100644
--- a/pyomo/mpec/tests/cov2_mpec.standard_form.txt
+++ b/pyomo/mpec/tests/cov2_mpec.standard_form.txt
@@ -1,2 +1,2 @@
-cc : Size=0, Index=cc_index, Active=True
+cc : Size=0, Index={0, 1, 2}, Active=True
     Key : Arg0 : Arg1 : Active
diff --git a/pyomo/mpec/tests/list1_None.txt b/pyomo/mpec/tests/list1_None.txt
index 8e849242bcd..34c358a1521 100644
--- a/pyomo/mpec/tests/list1_None.txt
+++ b/pyomo/mpec/tests/list1_None.txt
@@ -1,4 +1,4 @@
-cc : Size=2, Index=cc_index, Active=True
+cc : Size=2, Index={1, 2}, Active=True
     Key : Arg0   : Arg1             : Active
       1 : y + x3 : x1 + 2*x2  ==  0 :   True
       2 : y + x3 : x1 + 2*x2  ==  2 :   True
diff --git a/pyomo/mpec/tests/list1_mpec.nl.txt b/pyomo/mpec/tests/list1_mpec.nl.txt
index 16310c59317..62edc488b47 100644
--- a/pyomo/mpec/tests/list1_mpec.nl.txt
+++ b/pyomo/mpec/tests/list1_mpec.nl.txt
@@ -1,8 +1,3 @@
-1 Set Declarations
-    cc_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    2 : {1, 2}
-
 4 Var Declarations
     x1 : Size=1, Index=None
         Key  : Lower : Value : Upper : Fixed : Stale : Domain
@@ -18,7 +13,7 @@
         None :  None :  None :  None : False :  True :  Reals
 
 1 Block Declarations
-    cc : Size=2, Index=cc_index, Active=True
+    cc : Size=2, Index={1, 2}, Active=True
         Key : Arg0   : Arg1             : Active
           1 : y + x3 : x1 + 2*x2  ==  0 :   True
           2 : y + x3 : x1 + 2*x2  ==  2 :   True
@@ -37,4 +32,4 @@
 
             1 Declarations: c
 
-6 Declarations: y x1 x2 x3 cc_index cc
+5 Declarations: y x1 x2 x3 cc
diff --git a/pyomo/mpec/tests/list1_mpec.simple_disjunction.txt b/pyomo/mpec/tests/list1_mpec.simple_disjunction.txt
index 816e56af56c..c2bfe5e0399 100644
--- a/pyomo/mpec/tests/list1_mpec.simple_disjunction.txt
+++ b/pyomo/mpec/tests/list1_mpec.simple_disjunction.txt
@@ -1,4 +1,4 @@
-cc : Size=2, Index=cc_index, Active=True
+cc : Size=2, Index={1, 2}, Active=True
     Key : Arg0   : Arg1             : Active
       1 : y + x3 : x1 + 2*x2  ==  0 :   True
       2 : y + x3 : x1 + 2*x2  ==  2 :   True
diff --git a/pyomo/mpec/tests/list1_mpec.simple_nonlinear.txt b/pyomo/mpec/tests/list1_mpec.simple_nonlinear.txt
index 816e56af56c..c2bfe5e0399 100644
--- a/pyomo/mpec/tests/list1_mpec.simple_nonlinear.txt
+++ b/pyomo/mpec/tests/list1_mpec.simple_nonlinear.txt
@@ -1,4 +1,4 @@
-cc : Size=2, Index=cc_index, Active=True
+cc : Size=2, Index={1, 2}, Active=True
     Key : Arg0   : Arg1             : Active
       1 : y + x3 : x1 + 2*x2  ==  0 :   True
       2 : y + x3 : x1 + 2*x2  ==  2 :   True
diff --git a/pyomo/mpec/tests/list1_mpec.standard_form.txt b/pyomo/mpec/tests/list1_mpec.standard_form.txt
index 816e56af56c..c2bfe5e0399 100644
--- a/pyomo/mpec/tests/list1_mpec.standard_form.txt
+++ b/pyomo/mpec/tests/list1_mpec.standard_form.txt
@@ -1,4 +1,4 @@
-cc : Size=2, Index=cc_index, Active=True
+cc : Size=2, Index={1, 2}, Active=True
     Key : Arg0   : Arg1             : Active
       1 : y + x3 : x1 + 2*x2  ==  0 :   True
       2 : y + x3 : x1 + 2*x2  ==  2 :   True
diff --git a/pyomo/mpec/tests/list2_None.txt b/pyomo/mpec/tests/list2_None.txt
index cc84321fe3e..465bc347766 100644
--- a/pyomo/mpec/tests/list2_None.txt
+++ b/pyomo/mpec/tests/list2_None.txt
@@ -1,4 +1,4 @@
-cc : Size=3, Index=cc_index, Active=True
+cc : Size=3, Index={1, 2, 3}, Active=True
     Key : Arg0   : Arg1             : Active
       1 : y + x3 : x1 + 2*x2  ==  0 :   True
       2 : y + x3 : x1 + 2*x2  ==  1 :  False
diff --git a/pyomo/mpec/tests/list2_mpec.nl.txt b/pyomo/mpec/tests/list2_mpec.nl.txt
index c8c461e08e8..6dc49cef8dd 100644
--- a/pyomo/mpec/tests/list2_mpec.nl.txt
+++ b/pyomo/mpec/tests/list2_mpec.nl.txt
@@ -1,8 +1,3 @@
-1 Set Declarations
-    cc_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    3 : {1, 2, 3}
-
 4 Var Declarations
     x1 : Size=1, Index=None
         Key  : Lower : Value : Upper : Fixed : Stale : Domain
@@ -18,7 +13,7 @@
         None :  None :  None :  None : False :  True :  Reals
 
 1 Block Declarations
-    cc : Size=3, Index=cc_index, Active=True
+    cc : Size=3, Index={1, 2, 3}, Active=True
         Key : Arg0   : Arg1             : Active
           1 : y + x3 : x1 + 2*x2  ==  0 :   True
           2 : y + x3 : x1 + 2*x2  ==  1 :  False
@@ -40,4 +35,4 @@
 
             1 Declarations: c
 
-6 Declarations: y x1 x2 x3 cc_index cc
+5 Declarations: y x1 x2 x3 cc
diff --git a/pyomo/mpec/tests/list2_mpec.simple_disjunction.txt b/pyomo/mpec/tests/list2_mpec.simple_disjunction.txt
index 82688e8f017..c71d6461d22 100644
--- a/pyomo/mpec/tests/list2_mpec.simple_disjunction.txt
+++ b/pyomo/mpec/tests/list2_mpec.simple_disjunction.txt
@@ -1,4 +1,4 @@
-cc : Size=3, Index=cc_index, Active=True
+cc : Size=3, Index={1, 2, 3}, Active=True
     Key : Arg0   : Arg1             : Active
       1 : y + x3 : x1 + 2*x2  ==  0 :   True
       2 : y + x3 : x1 + 2*x2  ==  1 :  False
diff --git a/pyomo/mpec/tests/list2_mpec.simple_nonlinear.txt b/pyomo/mpec/tests/list2_mpec.simple_nonlinear.txt
index 82688e8f017..c71d6461d22 100644
--- a/pyomo/mpec/tests/list2_mpec.simple_nonlinear.txt
+++ b/pyomo/mpec/tests/list2_mpec.simple_nonlinear.txt
@@ -1,4 +1,4 @@
-cc : Size=3, Index=cc_index, Active=True
+cc : Size=3, Index={1, 2, 3}, Active=True
     Key : Arg0   : Arg1             : Active
       1 : y + x3 : x1 + 2*x2  ==  0 :   True
       2 : y + x3 : x1 + 2*x2  ==  1 :  False
diff --git a/pyomo/mpec/tests/list2_mpec.standard_form.txt b/pyomo/mpec/tests/list2_mpec.standard_form.txt
index 82688e8f017..c71d6461d22 100644
--- a/pyomo/mpec/tests/list2_mpec.standard_form.txt
+++ b/pyomo/mpec/tests/list2_mpec.standard_form.txt
@@ -1,4 +1,4 @@
-cc : Size=3, Index=cc_index, Active=True
+cc : Size=3, Index={1, 2, 3}, Active=True
     Key : Arg0   : Arg1             : Active
       1 : y + x3 : x1 + 2*x2  ==  0 :   True
       2 : y + x3 : x1 + 2*x2  ==  1 :  False
diff --git a/pyomo/mpec/tests/list5_None.txt b/pyomo/mpec/tests/list5_None.txt
index 8e6ed9a8164..962ee6cbc3a 100644
--- a/pyomo/mpec/tests/list5_None.txt
+++ b/pyomo/mpec/tests/list5_None.txt
@@ -1,4 +1,4 @@
-cc : Size=3, Index=cc_index, Active=True
+cc : Size=3, Index={1, 2, 3}, Active=True
     Key : Arg0   : Arg1             : Active
       1 : y + x3 : x1 + 2*x2  ==  0 :   True
       2 : y + x3 : x1 + 2*x2  ==  1 :   True
diff --git a/pyomo/mpec/tests/list5_mpec.nl.txt b/pyomo/mpec/tests/list5_mpec.nl.txt
index adb64af0457..93ee89f3389 100644
--- a/pyomo/mpec/tests/list5_mpec.nl.txt
+++ b/pyomo/mpec/tests/list5_mpec.nl.txt
@@ -1,8 +1,3 @@
-1 Set Declarations
-    cc_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    3 : {1, 2, 3}
-
 4 Var Declarations
     x1 : Size=1, Index=None
         Key  : Lower : Value : Upper : Fixed : Stale : Domain
@@ -18,7 +13,7 @@
         None :  None :  None :  None : False :  True :  Reals
 
 1 Block Declarations
-    cc : Size=3, Index=cc_index, Active=True
+    cc : Size=3, Index={1, 2, 3}, Active=True
         Key : Arg0   : Arg1             : Active
           1 : y + x3 : x1 + 2*x2  ==  0 :   True
           2 : y + x3 : x1 + 2*x2  ==  1 :   True
@@ -45,4 +40,4 @@
 
             1 Declarations: c
 
-6 Declarations: y x1 x2 x3 cc_index cc
+5 Declarations: y x1 x2 x3 cc
diff --git a/pyomo/mpec/tests/list5_mpec.simple_disjunction.txt b/pyomo/mpec/tests/list5_mpec.simple_disjunction.txt
index 69178523d96..15622fa84e1 100644
--- a/pyomo/mpec/tests/list5_mpec.simple_disjunction.txt
+++ b/pyomo/mpec/tests/list5_mpec.simple_disjunction.txt
@@ -1,4 +1,4 @@
-cc : Size=3, Index=cc_index, Active=True
+cc : Size=3, Index={1, 2, 3}, Active=True
     Key : Arg0   : Arg1             : Active
       1 : y + x3 : x1 + 2*x2  ==  0 :   True
       2 : y + x3 : x1 + 2*x2  ==  1 :   True
diff --git a/pyomo/mpec/tests/list5_mpec.simple_nonlinear.txt b/pyomo/mpec/tests/list5_mpec.simple_nonlinear.txt
index 69178523d96..15622fa84e1 100644
--- a/pyomo/mpec/tests/list5_mpec.simple_nonlinear.txt
+++ b/pyomo/mpec/tests/list5_mpec.simple_nonlinear.txt
@@ -1,4 +1,4 @@
-cc : Size=3, Index=cc_index, Active=True
+cc : Size=3, Index={1, 2, 3}, Active=True
     Key : Arg0   : Arg1             : Active
       1 : y + x3 : x1 + 2*x2  ==  0 :   True
       2 : y + x3 : x1 + 2*x2  ==  1 :   True
diff --git a/pyomo/mpec/tests/list5_mpec.standard_form.txt b/pyomo/mpec/tests/list5_mpec.standard_form.txt
index 69178523d96..15622fa84e1 100644
--- a/pyomo/mpec/tests/list5_mpec.standard_form.txt
+++ b/pyomo/mpec/tests/list5_mpec.standard_form.txt
@@ -1,4 +1,4 @@
-cc : Size=3, Index=cc_index, Active=True
+cc : Size=3, Index={1, 2, 3}, Active=True
     Key : Arg0   : Arg1             : Active
       1 : y + x3 : x1 + 2*x2  ==  0 :   True
       2 : y + x3 : x1 + 2*x2  ==  1 :   True
diff --git a/pyomo/mpec/tests/t10_None.txt b/pyomo/mpec/tests/t10_None.txt
index afc38166ab3..7d6b4c429cc 100644
--- a/pyomo/mpec/tests/t10_None.txt
+++ b/pyomo/mpec/tests/t10_None.txt
@@ -1,4 +1,4 @@
-cc : Size=3, Index=cc_index, Active=True
+cc : Size=3, Index={0, 1, 2}, Active=True
     Key : Arg0   : Arg1             : Active
       0 : y + x3 : x1 + 2*x2  ==  0 :   True
       1 : y + x3 : x1 + 2*x2  ==  1 :  False
diff --git a/pyomo/mpec/tests/t10_mpec.nl.txt b/pyomo/mpec/tests/t10_mpec.nl.txt
index a4a16713eaa..12db893ddba 100644
--- a/pyomo/mpec/tests/t10_mpec.nl.txt
+++ b/pyomo/mpec/tests/t10_mpec.nl.txt
@@ -1,8 +1,3 @@
-1 Set Declarations
-    cc_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    3 : {0, 1, 2}
-
 4 Var Declarations
     x1 : Size=1, Index=None
         Key  : Lower : Value : Upper : Fixed : Stale : Domain
@@ -18,7 +13,7 @@
         None :  None :  None :  None : False :  True :  Reals
 
 1 Block Declarations
-    cc : Size=3, Index=cc_index, Active=True
+    cc : Size=3, Index={0, 1, 2}, Active=True
         Key : Arg0   : Arg1             : Active
           0 : y + x3 : x1 + 2*x2  ==  0 :   True
           1 : y + x3 : x1 + 2*x2  ==  1 :  False
@@ -40,4 +35,4 @@
 
             1 Declarations: c
 
-6 Declarations: y x1 x2 x3 cc_index cc
+5 Declarations: y x1 x2 x3 cc
diff --git a/pyomo/mpec/tests/t10_mpec.simple_disjunction.txt b/pyomo/mpec/tests/t10_mpec.simple_disjunction.txt
index c53c1b8e62b..37aaaafcf68 100644
--- a/pyomo/mpec/tests/t10_mpec.simple_disjunction.txt
+++ b/pyomo/mpec/tests/t10_mpec.simple_disjunction.txt
@@ -1,4 +1,4 @@
-cc : Size=3, Index=cc_index, Active=True
+cc : Size=3, Index={0, 1, 2}, Active=True
     Key : Arg0   : Arg1             : Active
       0 : y + x3 : x1 + 2*x2  ==  0 :   True
       1 : y + x3 : x1 + 2*x2  ==  1 :  False
diff --git a/pyomo/mpec/tests/t10_mpec.simple_nonlinear.txt b/pyomo/mpec/tests/t10_mpec.simple_nonlinear.txt
index c53c1b8e62b..37aaaafcf68 100644
--- a/pyomo/mpec/tests/t10_mpec.simple_nonlinear.txt
+++ b/pyomo/mpec/tests/t10_mpec.simple_nonlinear.txt
@@ -1,4 +1,4 @@
-cc : Size=3, Index=cc_index, Active=True
+cc : Size=3, Index={0, 1, 2}, Active=True
     Key : Arg0   : Arg1             : Active
       0 : y + x3 : x1 + 2*x2  ==  0 :   True
       1 : y + x3 : x1 + 2*x2  ==  1 :  False
diff --git a/pyomo/mpec/tests/t10_mpec.standard_form.txt b/pyomo/mpec/tests/t10_mpec.standard_form.txt
index c53c1b8e62b..37aaaafcf68 100644
--- a/pyomo/mpec/tests/t10_mpec.standard_form.txt
+++ b/pyomo/mpec/tests/t10_mpec.standard_form.txt
@@ -1,4 +1,4 @@
-cc : Size=3, Index=cc_index, Active=True
+cc : Size=3, Index={0, 1, 2}, Active=True
     Key : Arg0   : Arg1             : Active
       0 : y + x3 : x1 + 2*x2  ==  0 :   True
       1 : y + x3 : x1 + 2*x2  ==  1 :  False
diff --git a/pyomo/mpec/tests/t13_None.txt b/pyomo/mpec/tests/t13_None.txt
index b2e24eb1166..fde3cc15a18 100644
--- a/pyomo/mpec/tests/t13_None.txt
+++ b/pyomo/mpec/tests/t13_None.txt
@@ -1,4 +1,4 @@
-cc : Size=2, Index=cc_index, Active=True
+cc : Size=2, Index={0, 1, 2}, Active=True
     Key : Arg0   : Arg1             : Active
       0 : y + x3 : x1 + 2*x2  ==  0 :   True
       2 : y + x3 : x1 + 2*x2  ==  2 :   True
diff --git a/pyomo/mpec/tests/t13_mpec.nl.txt b/pyomo/mpec/tests/t13_mpec.nl.txt
index dc47767efb7..9e709e35b6f 100644
--- a/pyomo/mpec/tests/t13_mpec.nl.txt
+++ b/pyomo/mpec/tests/t13_mpec.nl.txt
@@ -1,8 +1,3 @@
-1 Set Declarations
-    cc_index : Size=1, Index=None, Ordered=Insertion
-        Key  : Dimen : Domain : Size : Members
-        None :     1 :    Any :    3 : {0, 1, 2}
-
 4 Var Declarations
     x1 : Size=1, Index=None
         Key  : Lower : Value : Upper : Fixed : Stale : Domain
@@ -18,7 +13,7 @@
         None :  None :  None :  None : False :  True :  Reals
 
 1 Block Declarations
-    cc : Size=2, Index=cc_index, Active=True
+    cc : Size=2, Index={0, 1, 2}, Active=True
         Key : Arg0   : Arg1             : Active
           0 : y + x3 : x1 + 2*x2  ==  0 :   True
           2 : y + x3 : x1 + 2*x2  ==  2 :   True
@@ -37,4 +32,4 @@
 
             1 Declarations: c
 
-6 Declarations: y x1 x2 x3 cc_index cc
+5 Declarations: y x1 x2 x3 cc
diff --git a/pyomo/mpec/tests/t13_mpec.simple_disjunction.txt b/pyomo/mpec/tests/t13_mpec.simple_disjunction.txt
index 1ff09babad8..9b361c7e503 100644
--- a/pyomo/mpec/tests/t13_mpec.simple_disjunction.txt
+++ b/pyomo/mpec/tests/t13_mpec.simple_disjunction.txt
@@ -1,4 +1,4 @@
-cc : Size=2, Index=cc_index, Active=True
+cc : Size=2, Index={0, 1, 2}, Active=True
     Key : Arg0   : Arg1             : Active
       0 : y + x3 : x1 + 2*x2  ==  0 :   True
       2 : y + x3 : x1 + 2*x2  ==  2 :   True
diff --git a/pyomo/mpec/tests/t13_mpec.simple_nonlinear.txt b/pyomo/mpec/tests/t13_mpec.simple_nonlinear.txt
index 1ff09babad8..9b361c7e503 100644
--- a/pyomo/mpec/tests/t13_mpec.simple_nonlinear.txt
+++ b/pyomo/mpec/tests/t13_mpec.simple_nonlinear.txt
@@ -1,4 +1,4 @@
-cc : Size=2, Index=cc_index, Active=True
+cc : Size=2, Index={0, 1, 2}, Active=True
     Key : Arg0   : Arg1             : Active
       0 : y + x3 : x1 + 2*x2  ==  0 :   True
       2 : y + x3 : x1 + 2*x2  ==  2 :   True
diff --git a/pyomo/mpec/tests/t13_mpec.standard_form.txt b/pyomo/mpec/tests/t13_mpec.standard_form.txt
index 1ff09babad8..9b361c7e503 100644
--- a/pyomo/mpec/tests/t13_mpec.standard_form.txt
+++ b/pyomo/mpec/tests/t13_mpec.standard_form.txt
@@ -1,4 +1,4 @@
-cc : Size=2, Index=cc_index, Active=True
+cc : Size=2, Index={0, 1, 2}, Active=True
     Key : Arg0   : Arg1             : Active
       0 : y + x3 : x1 + 2*x2  ==  0 :   True
       2 : y + x3 : x1 + 2*x2  ==  2 :   True
diff --git a/pyomo/mpec/tests/test_complementarity.py b/pyomo/mpec/tests/test_complementarity.py
index 1eb0385c3e5..545104364cf 100644
--- a/pyomo/mpec/tests/test_complementarity.py
+++ b/pyomo/mpec/tests/test_complementarity.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/mpec/tests/test_minlp.py b/pyomo/mpec/tests/test_minlp.py
index 367a57b817e..965906f4235 100644
--- a/pyomo/mpec/tests/test_minlp.py
+++ b/pyomo/mpec/tests/test_minlp.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/mpec/tests/test_nlp.py b/pyomo/mpec/tests/test_nlp.py
index be5234136a1..a87d4ad2b09 100644
--- a/pyomo/mpec/tests/test_nlp.py
+++ b/pyomo/mpec/tests/test_nlp.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/mpec/tests/test_path.py b/pyomo/mpec/tests/test_path.py
index 5dd7178acf5..0501d19d2ac 100644
--- a/pyomo/mpec/tests/test_path.py
+++ b/pyomo/mpec/tests/test_path.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/neos/__init__.py b/pyomo/neos/__init__.py
index 73ac0c51216..9f910f4a302 100644
--- a/pyomo/neos/__init__.py
+++ b/pyomo/neos/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -30,7 +30,7 @@
     'minos': 'SLC NLP solver',
     'minto': 'MILP solver',
     'mosek': 'Interior point NLP solver',
-    'octeract': 'Deterministic global MINLP solver',
+    #'octeract': 'Deterministic global MINLP solver',
     'ooqp': 'Convex QP solver',
     'path': 'Nonlinear MCP solver',
     'snopt': 'SQP NLP solver',
diff --git a/pyomo/neos/kestrel.py b/pyomo/neos/kestrel.py
index 44734294eb4..8959a81bd0f 100644
--- a/pyomo/neos/kestrel.py
+++ b/pyomo/neos/kestrel.py
@@ -2,7 +2,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/neos/plugins/NEOS.py b/pyomo/neos/plugins/NEOS.py
index 85fad42d4b2..84bc51645c0 100644
--- a/pyomo/neos/plugins/NEOS.py
+++ b/pyomo/neos/plugins/NEOS.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/neos/plugins/__init__.py b/pyomo/neos/plugins/__init__.py
index 323f96e9bdc..75105e87088 100644
--- a/pyomo/neos/plugins/__init__.py
+++ b/pyomo/neos/plugins/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/neos/plugins/kestrel_plugin.py b/pyomo/neos/plugins/kestrel_plugin.py
index 49fb3809622..fecb98e0084 100644
--- a/pyomo/neos/plugins/kestrel_plugin.py
+++ b/pyomo/neos/plugins/kestrel_plugin.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/neos/tests/__init__.py b/pyomo/neos/tests/__init__.py
index 1cf642c0eac..83603e3d8ba 100644
--- a/pyomo/neos/tests/__init__.py
+++ b/pyomo/neos/tests/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/neos/tests/model_min_lp.py b/pyomo/neos/tests/model_min_lp.py
index 56e1b124cd4..eacf0451c94 100644
--- a/pyomo/neos/tests/model_min_lp.py
+++ b/pyomo/neos/tests/model_min_lp.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/neos/tests/test_neos.py b/pyomo/neos/tests/test_neos.py
index c43869e65cc..681856781be 100644
--- a/pyomo/neos/tests/test_neos.py
+++ b/pyomo/neos/tests/test_neos.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -79,6 +79,9 @@ def test_doc(self):
         doc = pyomo.neos.doc
         dockeys = set(doc.keys())
 
+        # Octeract interface is disabled, see #3321
+        amplsolvers.remove('octeract')
+
         self.assertEqual(amplsolvers, dockeys)
 
         # gamssolvers = set(v[0].lower() for v in tmp if v[1]=='GAMS')
@@ -149,8 +152,11 @@ def test_minto(self):
     def test_mosek(self):
         self._run('mosek')
 
-    def test_octeract(self):
-        self._run('octeract')
+    # [16 Jul 24] Octeract is erroring.  We will disable the interface
+    # (and testing) until we have time to resolve #3321
+    #
+    # def test_octeract(self):
+    #     self._run('octeract')
 
     def test_ooqp(self):
         if self.sense == pyo.maximize:
diff --git a/pyomo/network/__init__.py b/pyomo/network/__init__.py
index 097471102be..6ccfb64f79c 100644
--- a/pyomo/network/__init__.py
+++ b/pyomo/network/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/network/arc.py b/pyomo/network/arc.py
index ff1874b0274..f2597b4c1bd 100644
--- a/pyomo/network/arc.py
+++ b/pyomo/network/arc.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,8 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['Arc']
-
 from pyomo.network.port import Port
 from pyomo.core.base.component import ActiveComponentData, ModelComponentFactory
 from pyomo.core.base.indexed_component import (
@@ -54,7 +52,7 @@ def _iterable_to_dict(vals, directed, name):
     return vals
 
 
-class _ArcData(ActiveComponentData):
+class ArcData(ActiveComponentData):
     """
     This class defines the data for a single Arc
 
@@ -248,6 +246,11 @@ def _validate_ports(self, source, destination, ports):
                     )
 
 
+class _ArcData(metaclass=RenamedClass):
+    __renamed__new_class__ = ArcData
+    __renamed__version__ = '6.7.2'
+
+
 @ModelComponentFactory.register("Component used for connecting two Ports.")
 class Arc(ActiveIndexedComponent):
     """
@@ -269,7 +272,7 @@ class Arc(ActiveIndexedComponent):
             or a two-member iterable of ports
     """
 
-    _ComponentDataClass = _ArcData
+    _ComponentDataClass = ArcData
 
     def __new__(cls, *args, **kwds):
         if cls != Arc:
@@ -296,14 +299,18 @@ def __init__(self, *args, **kwds):
 
     def construct(self, data=None):
         """Initialize the Arc"""
-        if is_debug_set(logger):
-            logger.debug("Constructing Arc %s" % self.name)
-
         if self._constructed:
             return
+        self._constructed = True
+
+        if is_debug_set(logger):
+            logger.debug("Constructing Arc %s" % self.name)
 
         timer = ConstructionTimer(self)
-        self._constructed = True
+
+        if self._anonymous_sets is not None:
+            for _set in self._anonymous_sets:
+                _set.construct()
 
         if self._rule is None and self._init_vals is None:
             # No construction rule or values specified
@@ -371,9 +378,9 @@ def _pprint(self):
         )
 
 
-class ScalarArc(_ArcData, Arc):
+class ScalarArc(ArcData, Arc):
     def __init__(self, *args, **kwds):
-        _ArcData.__init__(self, self)
+        ArcData.__init__(self, self)
         Arc.__init__(self, *args, **kwds)
         self.index = UnindexedComponent_index
 
diff --git a/pyomo/network/decomposition.py b/pyomo/network/decomposition.py
index ae306766ae0..1ffb6a710ff 100644
--- a/pyomo/network/decomposition.py
+++ b/pyomo/network/decomposition.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,8 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['SequentialDecomposition']
-
 from pyomo.network import Port, Arc
 from pyomo.network.foqus_graph import FOQUSGraph
 from pyomo.core import (
diff --git a/pyomo/network/foqus_graph.py b/pyomo/network/foqus_graph.py
index e6fc34aaf62..7c6c05256d9 100644
--- a/pyomo/network/foqus_graph.py
+++ b/pyomo/network/foqus_graph.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -358,9 +358,9 @@ def scc_calculation_order(self, sccNodes, ie, oe):
         done = False
         for i in range(len(sccNodes)):
             for j in range(len(sccNodes)):
-                for ine in ie[i]:
-                    for oute in oe[j]:
-                        if ine == oute:
+                for in_e in ie[i]:
+                    for out_e in oe[j]:
+                        if in_e == out_e:
                             adj[j].append(i)
                             adjR[i].append(j)
                             done = True
diff --git a/pyomo/network/plugins/__init__.py b/pyomo/network/plugins/__init__.py
index 5e9677d2bc4..ab3cde23daa 100644
--- a/pyomo/network/plugins/__init__.py
+++ b/pyomo/network/plugins/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/network/plugins/expand_arcs.py b/pyomo/network/plugins/expand_arcs.py
index 4f6185d3173..b1f915214eb 100644
--- a/pyomo/network/plugins/expand_arcs.py
+++ b/pyomo/network/plugins/expand_arcs.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/network/port.py b/pyomo/network/port.py
index 4afb0e23ed0..f6706dce644 100644
--- a/pyomo/network/port.py
+++ b/pyomo/network/port.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,8 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['Port']
-
 import logging, sys
 from weakref import ref as weakref_ref
 
@@ -38,7 +36,7 @@
 logger = logging.getLogger('pyomo.network')
 
 
-class _PortData(ComponentData):
+class PortData(ComponentData):
     """
     This class defines the data for a single Port
 
@@ -287,6 +285,11 @@ def get_split_fraction(self, arc):
             return res
 
 
+class _PortData(metaclass=RenamedClass):
+    __renamed__new_class__ = PortData
+    __renamed__version__ = '6.7.2'
+
+
 @ModelComponentFactory.register(
     "A bundle of variables that can be connected to other ports."
 )
@@ -341,21 +344,25 @@ def __init__(self, *args, **kwd):
     # IndexedComponent that support implicit definition
     def _getitem_when_not_present(self, idx):
         """Returns the default component data value."""
-        tmp = self._data[idx] = _PortData(component=self)
+        tmp = self._data[idx] = PortData(component=self)
         tmp._index = idx
         return tmp
 
     def construct(self, data=None):
-        if is_debug_set(logger):  # pragma:nocover
-            logger.debug("Constructing Port, name=%s, from data=%s" % (self.name, data))
-
         if self._constructed:
             return
+        self._constructed = True
 
         timer = ConstructionTimer(self)
-        self._constructed = True
 
-        # Construct _PortData objects for all index values
+        if is_debug_set(logger):  # pragma:nocover
+            logger.debug("Constructing Port, name=%s, from data=%s" % (self.name, data))
+
+        if self._anonymous_sets is not None:
+            for _set in self._anonymous_sets:
+                _set.construct()
+
+        # Construct PortData objects for all index values
         if self.is_indexed():
             self._initialize_members(self._index_set)
         else:
@@ -761,9 +768,9 @@ def _create_evar(member, name, eblock, index_set):
         return evar
 
 
-class ScalarPort(Port, _PortData):
+class ScalarPort(Port, PortData):
     def __init__(self, *args, **kwd):
-        _PortData.__init__(self, component=self)
+        PortData.__init__(self, component=self)
         Port.__init__(self, *args, **kwd)
         self._index = UnindexedComponent_index
 
diff --git a/pyomo/network/tests/__init__.py b/pyomo/network/tests/__init__.py
index 1eb6d95e148..173fdc4e727 100644
--- a/pyomo/network/tests/__init__.py
+++ b/pyomo/network/tests/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/network/tests/test_arc.py b/pyomo/network/tests/test_arc.py
index cd340cace7a..8356bcce9d8 100644
--- a/pyomo/network/tests/test_arc.py
+++ b/pyomo/network/tests/test_arc.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -504,11 +504,11 @@ def test_expand_indexed(self):
             os.getvalue(),
             """c_expanded : Size=1, Index=None, Active=True
     3 Constraint Declarations
-        a_equality : Size=2, Index=x_index, Active=True
+        a_equality : Size=2, Index={1, 2}, Active=True
             Key : Lower : Body        : Upper : Active
               1 :   0.0 : x[1] - t[1] :   0.0 :   True
               2 :   0.0 : x[2] - t[2] :   0.0 :   True
-        b_equality : Size=4, Index=y_index, Active=True
+        b_equality : Size=4, Index={1, 2}*{1, 2}, Active=True
             Key    : Lower : Body            : Upper : Active
             (1, 1) :   0.0 : y[1,1] - u[1,1] :   0.0 :   True
             (1, 2) :   0.0 : y[1,2] - u[1,2] :   0.0 :   True
@@ -677,7 +677,7 @@ def test_expand_empty_indexed(self):
             os.getvalue(),
             """c_expanded : Size=1, Index=None, Active=True
     2 Constraint Declarations
-        x_equality : Size=2, Index=x_index, Active=True
+        x_equality : Size=2, Index={1, 2}, Active=True
             Key : Lower : Body                  : Upper : Active
               1 :   0.0 : x[1] - EPRT_auto_x[1] :   0.0 :   True
               2 :   0.0 : x[2] - EPRT_auto_x[2] :   0.0 :   True
@@ -739,7 +739,7 @@ def test_expand_multiple_empty_indexed(self):
             os.getvalue(),
             """c_expanded : Size=1, Index=None, Active=True
     2 Constraint Declarations
-        x_equality : Size=2, Index=x_index, Active=True
+        x_equality : Size=2, Index={1, 2}, Active=True
             Key : Lower : Body                   : Upper : Active
               1 :   0.0 : x[1] - EPRT1_auto_x[1] :   0.0 :   True
               2 :   0.0 : x[2] - EPRT1_auto_x[2] :   0.0 :   True
@@ -757,7 +757,7 @@ def test_expand_multiple_empty_indexed(self):
             os.getvalue(),
             """d_expanded : Size=1, Index=None, Active=True
     2 Constraint Declarations
-        x_equality : Size=2, Index=x_index, Active=True
+        x_equality : Size=2, Index={1, 2}, Active=True
             Key : Lower : Body                              : Upper : Active
               1 :   0.0 : EPRT2_auto_x[1] - EPRT1_auto_x[1] :   0.0 :   True
               2 :   0.0 : EPRT2_auto_x[2] - EPRT1_auto_x[2] :   0.0 :   True
@@ -812,7 +812,7 @@ def test_expand_multiple_indexed(self):
             os.getvalue(),
             """c_expanded : Size=1, Index=None, Active=True
     2 Constraint Declarations
-        x_equality : Size=2, Index=x_index, Active=True
+        x_equality : Size=2, Index={1, 2}, Active=True
             Key : Lower : Body         : Upper : Active
               1 :   0.0 : x[1] - a1[1] :   0.0 :   True
               2 :   0.0 : x[2] - a1[2] :   0.0 :   True
@@ -830,7 +830,7 @@ def test_expand_multiple_indexed(self):
             os.getvalue(),
             """d_expanded : Size=1, Index=None, Active=True
     2 Constraint Declarations
-        x_equality : Size=2, Index=x_index, Active=True
+        x_equality : Size=2, Index={1, 2}, Active=True
             Key : Lower : Body          : Upper : Active
               1 :   0.0 : a2[1] - a1[1] :   0.0 :   True
               2 :   0.0 : a2[2] - a1[2] :   0.0 :   True
@@ -903,7 +903,7 @@ def test_expand_implicit_indexed(self):
             os.getvalue(),
             """c_expanded : Size=1, Index=None, Active=True
     2 Constraint Declarations
-        x_equality : Size=2, Index=a2_index, Active=True
+        x_equality : Size=2, Index={1, 2}, Active=True
             Key : Lower : Body         : Upper : Active
               1 :   0.0 : a2[1] - x[1] :   0.0 :   True
               2 :   0.0 : a2[2] - x[2] :   0.0 :   True
@@ -921,7 +921,7 @@ def test_expand_implicit_indexed(self):
             os.getvalue(),
             """d_expanded : Size=1, Index=None, Active=True
     2 Constraint Declarations
-        x_equality : Size=2, Index=a2_index, Active=True
+        x_equality : Size=2, Index={1, 2}, Active=True
             Key : Lower : Body                   : Upper : Active
               1 :   0.0 : EPRT2_auto_x[1] - x[1] :   0.0 :   True
               2 :   0.0 : EPRT2_auto_x[2] - x[2] :   0.0 :   True
@@ -964,7 +964,7 @@ def rule(m, i):
         m.component('eq_expanded').pprint(ostream=os)
         self.assertEqual(
             os.getvalue(),
-            """eq_expanded : Size=2, Index=eq_index, Active=True
+            """eq_expanded : Size=2, Index={1, 2}, Active=True
     eq_expanded[1] : Active=True
         1 Constraint Declarations
             v_equality : Size=1, Index=None, Active=True
diff --git a/pyomo/network/tests/test_decomposition.py b/pyomo/network/tests/test_decomposition.py
index 4e4d0231d00..2db310217d0 100644
--- a/pyomo/network/tests/test_decomposition.py
+++ b/pyomo/network/tests/test_decomposition.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/network/tests/test_port.py b/pyomo/network/tests/test_port.py
index bc9a6fc527f..a417a832015 100644
--- a/pyomo/network/tests/test_port.py
+++ b/pyomo/network/tests/test_port.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/network/util.py b/pyomo/network/util.py
index be0fa2c84d1..4865218aca8 100644
--- a/pyomo/network/util.py
+++ b/pyomo/network/util.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/opt/__init__.py b/pyomo/opt/__init__.py
index 8c12d3fa201..c78dd0384d2 100644
--- a/pyomo/opt/__init__.py
+++ b/pyomo/opt/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/opt/base/__init__.py b/pyomo/opt/base/__init__.py
index 9d29efc859d..8d11114dd09 100644
--- a/pyomo/opt/base/__init__.py
+++ b/pyomo/opt/base/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/opt/base/convert.py b/pyomo/opt/base/convert.py
index 8d8bd78e2ee..28ad6727d3e 100644
--- a/pyomo/opt/base/convert.py
+++ b/pyomo/opt/base/convert.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,8 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['convert_problem']
-
 import copy
 import os
 
diff --git a/pyomo/opt/base/error.py b/pyomo/opt/base/error.py
index aa97469f6d0..b03fafd7037 100644
--- a/pyomo/opt/base/error.py
+++ b/pyomo/opt/base/error.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/opt/base/formats.py b/pyomo/opt/base/formats.py
index 2acd77b80e4..6e9d3958f48 100644
--- a/pyomo/opt/base/formats.py
+++ b/pyomo/opt/base/formats.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,11 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-#
-# The formats that are supported by Pyomo
-#
-__all__ = ['ProblemFormat', 'ResultsFormat', 'guess_format']
-
 import enum
 
 
diff --git a/pyomo/opt/base/opt_config.py b/pyomo/opt/base/opt_config.py
index d93cfd77b3c..a4a626013c4 100644
--- a/pyomo/opt/base/opt_config.py
+++ b/pyomo/opt/base/opt_config.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/opt/base/problem.py b/pyomo/opt/base/problem.py
index 6be1d4d6db6..804a97e2e4c 100644
--- a/pyomo/opt/base/problem.py
+++ b/pyomo/opt/base/problem.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,8 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ["AbstractProblemWriter", "WriterFactory", "BranchDirection"]
-
 from pyomo.common import Factory
 
 
diff --git a/pyomo/opt/base/results.py b/pyomo/opt/base/results.py
index 68999fae6e4..ea295a66315 100644
--- a/pyomo/opt/base/results.py
+++ b/pyomo/opt/base/results.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,8 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['AbstractResultsReader', 'ReaderFactory']
-
 from pyomo.common import Factory
 
 
diff --git a/pyomo/opt/base/solvers.py b/pyomo/opt/base/solvers.py
index b11e6393b02..c0698165603 100644
--- a/pyomo/opt/base/solvers.py
+++ b/pyomo/opt/base/solvers.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,8 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ('OptSolver', 'SolverFactory', 'UnknownSolver', 'check_available_solvers')
-
 import re
 import sys
 import time
@@ -18,12 +16,11 @@
 import shlex
 
 from pyomo.common import Factory
-from pyomo.common.config import ConfigDict
 from pyomo.common.errors import ApplicationError
 from pyomo.common.collections import Bunch
 
 from pyomo.opt.base.convert import convert_problem
-from pyomo.opt.base.formats import ResultsFormat, ProblemFormat
+from pyomo.opt.base.formats import ResultsFormat
 import pyomo.opt.base.results
 
 logger = logging.getLogger('pyomo.opt')
@@ -181,7 +178,11 @@ def __call__(self, _name=None, **kwds):
         return opt
 
 
+LegacySolverFactory = SolverFactoryClass('solver type')
+
 SolverFactory = SolverFactoryClass('solver type')
+SolverFactory._cls = LegacySolverFactory._cls
+SolverFactory._doc = LegacySolverFactory._doc
 
 
 #
@@ -535,15 +536,15 @@ def solve(self, *args, **kwds):
         # If the inputs are models, then validate that they have been
         # constructed! Collect suffix names to try and import from solution.
         #
-        from pyomo.core.base.block import _BlockData
+        from pyomo.core.base.block import BlockData
         import pyomo.core.base.suffix
         from pyomo.core.kernel.block import IBlock
         import pyomo.core.kernel.suffix
 
         _model = None
         for arg in args:
-            if isinstance(arg, (_BlockData, IBlock)):
-                if isinstance(arg, _BlockData):
+            if isinstance(arg, (BlockData, IBlock)):
+                if isinstance(arg, BlockData):
                     if not arg.is_constructed():
                         raise RuntimeError(
                             "Attempting to solve model=%s with unconstructed "
@@ -552,7 +553,7 @@ def solve(self, *args, **kwds):
 
                 _model = arg
                 # import suffixes must be on the top-level model
-                if isinstance(arg, _BlockData):
+                if isinstance(arg, BlockData):
                     model_suffixes = list(
                         name
                         for (
diff --git a/pyomo/opt/parallel/__init__.py b/pyomo/opt/parallel/__init__.py
index 9820f39afd4..dbfdf2302ca 100644
--- a/pyomo/opt/parallel/__init__.py
+++ b/pyomo/opt/parallel/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/opt/parallel/async_solver.py b/pyomo/opt/parallel/async_solver.py
index e9806b7125a..74e222e2241 100644
--- a/pyomo/opt/parallel/async_solver.py
+++ b/pyomo/opt/parallel/async_solver.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,9 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-
-__all__ = ['AsynchronousSolverManager', 'SolverManagerFactory']
-
 from pyomo.common import Factory
 from pyomo.opt.parallel.manager import AsynchronousActionManager
 
diff --git a/pyomo/opt/parallel/local.py b/pyomo/opt/parallel/local.py
index a7a80a7d33c..e130ea0407f 100644
--- a/pyomo/opt/parallel/local.py
+++ b/pyomo/opt/parallel/local.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,9 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-
-__all__ = ()
-
 import time
 
 from pyomo.common.collections import OrderedDict
diff --git a/pyomo/opt/parallel/manager.py b/pyomo/opt/parallel/manager.py
index a97f6ae1d27..203c348e119 100644
--- a/pyomo/opt/parallel/manager.py
+++ b/pyomo/opt/parallel/manager.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,16 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-
-__all__ = [
-    'ActionManagerError',
-    'ActionHandle',
-    'AsynchronousActionManager',
-    'ActionStatus',
-    'FailedActionHandle',
-    'solve_all_instances',
-]
-
 import enum
 
 
diff --git a/pyomo/opt/plugins/__init__.py b/pyomo/opt/plugins/__init__.py
index 797147f5f69..5ea2490b534 100644
--- a/pyomo/opt/plugins/__init__.py
+++ b/pyomo/opt/plugins/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/opt/plugins/driver.py b/pyomo/opt/plugins/driver.py
index 23757053beb..c7c7103835c 100644
--- a/pyomo/opt/plugins/driver.py
+++ b/pyomo/opt/plugins/driver.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/opt/plugins/res.py b/pyomo/opt/plugins/res.py
index 25d25d5feb0..31971ee7d25 100644
--- a/pyomo/opt/plugins/res.py
+++ b/pyomo/opt/plugins/res.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/opt/plugins/sol.py b/pyomo/opt/plugins/sol.py
index 297b1c87d06..10da469f186 100644
--- a/pyomo/opt/plugins/sol.py
+++ b/pyomo/opt/plugins/sol.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/opt/problem/__init__.py b/pyomo/opt/problem/__init__.py
index 1b1a5328beb..8199553247d 100644
--- a/pyomo/opt/problem/__init__.py
+++ b/pyomo/opt/problem/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/opt/problem/ampl.py b/pyomo/opt/problem/ampl.py
index 625c342f005..ed107cace60 100644
--- a/pyomo/opt/problem/ampl.py
+++ b/pyomo/opt/problem/ampl.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -14,8 +14,6 @@
 can be optimized with the Acro COLIN optimizers.
 """
 
-__all__ = ['AmplModel']
-
 import os
 
 from pyomo.opt.base import ProblemFormat, convert_problem, guess_format
diff --git a/pyomo/opt/results/__init__.py b/pyomo/opt/results/__init__.py
index 8b2933adfe0..64a1b42ac86 100644
--- a/pyomo/opt/results/__init__.py
+++ b/pyomo/opt/results/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/opt/results/container.py b/pyomo/opt/results/container.py
index 98a68048b45..4bbaf44edf7 100644
--- a/pyomo/opt/results/container.py
+++ b/pyomo/opt/results/container.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,24 +9,12 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = [
-    'UndefinedData',
-    'undefined',
-    'ignore',
-    'ScalarData',
-    'ListContainer',
-    'MapContainer',
-    'default_print_options',
-    'ScalarType',
-]
-
 import copy
-
-from math import inf
-from pyomo.common.collections import Bunch
-
 import enum
 from io import StringIO
+from math import inf
+
+from pyomo.common.collections import Bunch
 
 
 class ScalarType(str, enum.Enum):
diff --git a/pyomo/opt/results/problem.py b/pyomo/opt/results/problem.py
index 71fd748dd81..a8eca1e3b41 100644
--- a/pyomo/opt/results/problem.py
+++ b/pyomo/opt/results/problem.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,24 +9,19 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['ProblemInformation', 'ProblemSense']
-
 import enum
 from pyomo.opt.results.container import MapContainer
 
+from pyomo.common.enums import ExtendedEnumType, ObjectiveSense
+
+
+class ProblemSense(enum.IntEnum, metaclass=ExtendedEnumType):
+    __base_enum__ = ObjectiveSense
 
-class ProblemSense(str, enum.Enum):
-    unknown = 'unknown'
-    minimize = 'minimize'
-    maximize = 'maximize'
+    unknown = 0
 
-    # Overloading __str__ is needed to match the behavior of the old
-    # pyutilib.enum class (removed June 2020). There are spots in the
-    # code base that expect the string representation for items in the
-    # enum to not include the class name. New uses of enum shouldn't
-    # need to do this.
     def __str__(self):
-        return self.value
+        return self.name
 
 
 class ProblemInformation(MapContainer):
diff --git a/pyomo/opt/results/results_.py b/pyomo/opt/results/results_.py
index 2852bb72e8a..0a045550517 100644
--- a/pyomo/opt/results/results_.py
+++ b/pyomo/opt/results/results_.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,8 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['SolverResults']
-
 import math
 import sys
 import copy
@@ -18,7 +16,7 @@
 import logging
 import os.path
 
-from pyomo.common.dependencies import yaml, yaml_load_args, yaml_available
+from pyomo.common.dependencies import yaml, yaml_load_args
 import pyomo.opt
 from pyomo.opt.results.container import undefined, ignore, ListContainer, MapContainer
 import pyomo.opt.results.solution
diff --git a/pyomo/opt/results/solution.py b/pyomo/opt/results/solution.py
index 0cb8e92e730..6dcd348ea72 100644
--- a/pyomo/opt/results/solution.py
+++ b/pyomo/opt/results/solution.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,8 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['SolutionStatus', 'Solution']
-
 import math
 import enum
 from pyomo.opt.results.container import MapContainer, ListContainer, ignore
diff --git a/pyomo/opt/results/solver.py b/pyomo/opt/results/solver.py
index 5f9ceb3b68e..d4cf46c38a9 100644
--- a/pyomo/opt/results/solver.py
+++ b/pyomo/opt/results/solver.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,14 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = [
-    'SolverInformation',
-    'SolverStatus',
-    'TerminationCondition',
-    'check_optimal_termination',
-    'assert_optimal_termination',
-]
-
 import enum
 from pyomo.opt.results.container import MapContainer, ScalarType
 
diff --git a/pyomo/opt/solver/__init__.py b/pyomo/opt/solver/__init__.py
index 961d7e0edbd..6da73d408fa 100644
--- a/pyomo/opt/solver/__init__.py
+++ b/pyomo/opt/solver/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/opt/solver/ilmcmd.py b/pyomo/opt/solver/ilmcmd.py
index d08feab7d9a..c956b2ed42f 100644
--- a/pyomo/opt/solver/ilmcmd.py
+++ b/pyomo/opt/solver/ilmcmd.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,8 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['ILMLicensedSystemCallSolver']
-
 import re
 import sys
 import os
diff --git a/pyomo/opt/solver/shellcmd.py b/pyomo/opt/solver/shellcmd.py
index 20892000066..baa0369e1d6 100644
--- a/pyomo/opt/solver/shellcmd.py
+++ b/pyomo/opt/solver/shellcmd.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,8 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['SystemCallSolver']
-
 import os
 import sys
 import time
@@ -62,6 +60,7 @@ def __init__(self, **kwargs):
         # a solver plugin may not report execution time.
         self._last_solve_time = None
         self._define_signal_handlers = None
+        self._version_timeout = 2
 
         if executable is not None:
             self.set_executable(name=executable, validate=validate)
diff --git a/pyomo/opt/testing/__init__.py b/pyomo/opt/testing/__init__.py
index 5d0d8ebd8d7..37ed419fbe3 100644
--- a/pyomo/opt/testing/__init__.py
+++ b/pyomo/opt/testing/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/opt/testing/pyunit.py b/pyomo/opt/testing/pyunit.py
index 527b72cec7a..bb96806d520 100644
--- a/pyomo/opt/testing/pyunit.py
+++ b/pyomo/opt/testing/pyunit.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,9 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-
-__all__ = ['TestCase']
-
 import sys
 import os
 import re
diff --git a/pyomo/opt/tests/__init__.py b/pyomo/opt/tests/__init__.py
index 65dc8785c9b..b333eb78878 100644
--- a/pyomo/opt/tests/__init__.py
+++ b/pyomo/opt/tests/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/opt/tests/base/__init__.py b/pyomo/opt/tests/base/__init__.py
index dbebb21e4f1..cde23945b56 100644
--- a/pyomo/opt/tests/base/__init__.py
+++ b/pyomo/opt/tests/base/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/opt/tests/base/test_ampl.py b/pyomo/opt/tests/base/test_ampl.py
index 1baffcbb0af..d37befcac57 100644
--- a/pyomo/opt/tests/base/test_ampl.py
+++ b/pyomo/opt/tests/base/test_ampl.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/opt/tests/base/test_convert.py b/pyomo/opt/tests/base/test_convert.py
index f8f0bef0fe4..30a8fb0d1fc 100644
--- a/pyomo/opt/tests/base/test_convert.py
+++ b/pyomo/opt/tests/base/test_convert.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/opt/tests/base/test_factory.py b/pyomo/opt/tests/base/test_factory.py
index ab2a64a6330..441ba245c5e 100644
--- a/pyomo/opt/tests/base/test_factory.py
+++ b/pyomo/opt/tests/base/test_factory.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/opt/tests/base/test_sol.py b/pyomo/opt/tests/base/test_sol.py
index ff233b42a43..fada795b925 100644
--- a/pyomo/opt/tests/base/test_sol.py
+++ b/pyomo/opt/tests/base/test_sol.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/opt/tests/base/test_soln.py b/pyomo/opt/tests/base/test_soln.py
index 0511b3ceb9c..d39baeab15f 100644
--- a/pyomo/opt/tests/base/test_soln.py
+++ b/pyomo/opt/tests/base/test_soln.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/opt/tests/base/test_solver.py b/pyomo/opt/tests/base/test_solver.py
index 73d6067efe4..8ffc647804d 100644
--- a/pyomo/opt/tests/base/test_solver.py
+++ b/pyomo/opt/tests/base/test_solver.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/opt/tests/solver/__init__.py b/pyomo/opt/tests/solver/__init__.py
index 4c145a1b507..d27a8ab41d6 100644
--- a/pyomo/opt/tests/solver/__init__.py
+++ b/pyomo/opt/tests/solver/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/opt/tests/solver/test_shellcmd.py b/pyomo/opt/tests/solver/test_shellcmd.py
index f71fcf07c6d..b6cc264b8f7 100644
--- a/pyomo/opt/tests/solver/test_shellcmd.py
+++ b/pyomo/opt/tests/solver/test_shellcmd.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/pysp/__init__.py b/pyomo/pysp/__init__.py
index 3fb4abbbd42..bb8a401e45e 100644
--- a/pyomo/pysp/__init__.py
+++ b/pyomo/pysp/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/__init__.py b/pyomo/repn/__init__.py
index 1b27071c404..842f4750127 100644
--- a/pyomo/repn/__init__.py
+++ b/pyomo/repn/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/beta/__init__.py b/pyomo/repn/beta/__init__.py
index fd7fac1125a..a75a75ec760 100644
--- a/pyomo/repn/beta/__init__.py
+++ b/pyomo/repn/beta/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/beta/matrix.py b/pyomo/repn/beta/matrix.py
index ff2d6857bd6..0201c46eb18 100644
--- a/pyomo/repn/beta/matrix.py
+++ b/pyomo/repn/beta/matrix.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,12 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = (
-    "_LinearConstraintData",
-    "MatrixConstraint",
-    "compile_block_linear_constraints",
-)
-
 import time
 import logging
 import array
@@ -30,7 +24,7 @@
     Constraint,
     IndexedConstraint,
     ScalarConstraint,
-    _ConstraintData,
+    ConstraintData,
 )
 from pyomo.core.expr.numvalue import native_numeric_types
 from pyomo.repn import generate_standard_repn
@@ -253,7 +247,7 @@ def _get_bound(exp):
         constraint_containers_removed += 1
     for constraint, index in constraint_data_to_remove:
         # Note that this del is not needed: assigning Constraint.Skip
-        # above removes the _ConstraintData from the _data dict.
+        # above removes the ConstraintData from the _data dict.
         # del constraint[index]
         constraints_removed += 1
     for block, constraint in constraint_containers_to_remove:
@@ -354,12 +348,12 @@ def _get_bound(exp):
     )
 
 
-# class _LinearConstraintData(_ConstraintData,LinearCanonicalRepn):
+# class _LinearConstraintData(ConstraintData,LinearCanonicalRepn):
 #
 # This change breaks this class, but it's unclear whether this
 # is being used...
 #
-class _LinearConstraintData(_ConstraintData):
+class _LinearConstraintData(ConstraintData):
     """
     This class defines the data for a single linear constraint
         in canonical form.
@@ -399,7 +393,7 @@ def __init__(self, index, component=None):
         #
         # These lines represent in-lining of the
         # following constructors:
-        #   - _ConstraintData,
+        #   - ConstraintData,
         #   - ActiveComponentData
         #   - ComponentData
         self._component = weakref_ref(component) if (component is not None) else None
@@ -448,7 +442,7 @@ def __init__(self, index, component=None):
         # These lines represent in-lining of the
         # following constructors:
         #   - _LinearConstraintData
-        #   - _ConstraintData,
+        #   - ConstraintData,
         #   - ActiveComponentData
         #   - ComponentData
         self._component = weakref_ref(component) if (component is not None) else None
@@ -590,7 +584,7 @@ def constant(self):
         return sum(terms)
 
     #
-    # Abstract Interface (_ConstraintData)
+    # Abstract Interface (ConstraintData)
     #
 
     @property
diff --git a/pyomo/repn/linear.py b/pyomo/repn/linear.py
index 59bc0b58d99..029fe892b62 100644
--- a/pyomo/repn/linear.py
+++ b/pyomo/repn/linear.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -31,8 +31,8 @@
     MonomialTermExpression,
     LinearExpression,
     SumExpression,
-    NPV_SumExpression,
     ExternalFunctionExpression,
+    mutable_expression,
 )
 from pyomo.core.expr.relational_expr import (
     EqualityExpression,
@@ -120,22 +120,14 @@ def to_expression(self, visitor):
             ans = 0
         if self.linear:
             var_map = visitor.var_map
-            if len(self.linear) == 1:
-                vid, coef = next(iter(self.linear.items()))
-                if coef == 1:
-                    ans += var_map[vid]
-                elif coef:
-                    ans += MonomialTermExpression((coef, var_map[vid]))
-                else:
-                    pass
-            else:
-                ans += LinearExpression(
-                    [
-                        MonomialTermExpression((coef, var_map[vid]))
-                        for vid, coef in self.linear.items()
-                        if coef
-                    ]
-                )
+            with mutable_expression() as e:
+                for vid, coef in self.linear.items():
+                    if coef:
+                        e += coef * var_map[vid]
+            if e.nargs() > 1:
+                ans += e
+            elif e.nargs() == 1:
+                ans += e.arg(0)
         if self.constant:
             ans += self.constant
         if self.multiplier != 1:
@@ -191,8 +183,6 @@ def to_expression(visitor, arg):
         return arg[1].to_expression(visitor)
 
 
-_exit_node_handlers = {}
-
 #
 # NEGATION handlers
 #
@@ -207,32 +197,24 @@ def _handle_negation_ANY(visitor, node, arg):
     return arg
 
 
-_exit_node_handlers[NegationExpression] = {
-    (_CONSTANT,): _handle_negation_constant,
-    (_LINEAR,): _handle_negation_ANY,
-    (_GENERAL,): _handle_negation_ANY,
-}
-
 #
 # PRODUCT handlers
 #
 
 
 def _handle_product_constant_constant(visitor, node, arg1, arg2):
-    _, arg1 = arg1
-    _, arg2 = arg2
-    ans = arg1 * arg2
+    ans = arg1[1] * arg2[1]
     if ans != ans:
-        if not arg1 or not arg2:
+        if not arg1[1] or not arg2[1]:
             deprecation_warning(
-                f"Encountered {str(arg1)}*{str(arg2)} in expression tree.  "
+                f"Encountered {str(arg1[1])}*{str(arg2[1])} in expression tree.  "
                 "Mapping the NaN result to 0 for compatibility "
                 "with the lp_v1 writer.  In the future, this NaN "
                 "will be preserved/emitted to comply with IEEE-754.",
                 version='6.6.0',
             )
-            return _, 0
-    return _, arg1 * arg2
+            return _CONSTANT, 0
+    return _CONSTANT, ans
 
 
 def _handle_product_constant_ANY(visitor, node, arg1, arg2):
@@ -283,19 +265,6 @@ def _handle_product_nonlinear(visitor, node, arg1, arg2):
     return _GENERAL, ans
 
 
-_exit_node_handlers[ProductExpression] = {
-    (_CONSTANT, _CONSTANT): _handle_product_constant_constant,
-    (_CONSTANT, _LINEAR): _handle_product_constant_ANY,
-    (_CONSTANT, _GENERAL): _handle_product_constant_ANY,
-    (_LINEAR, _CONSTANT): _handle_product_ANY_constant,
-    (_LINEAR, _LINEAR): _handle_product_nonlinear,
-    (_LINEAR, _GENERAL): _handle_product_nonlinear,
-    (_GENERAL, _CONSTANT): _handle_product_ANY_constant,
-    (_GENERAL, _LINEAR): _handle_product_nonlinear,
-    (_GENERAL, _GENERAL): _handle_product_nonlinear,
-}
-_exit_node_handlers[MonomialTermExpression] = _exit_node_handlers[ProductExpression]
-
 #
 # DIVISION handlers
 #
@@ -306,7 +275,7 @@ def _handle_division_constant_constant(visitor, node, arg1, arg2):
 
 
 def _handle_division_ANY_constant(visitor, node, arg1, arg2):
-    arg1[1].multiplier /= arg2[1]
+    arg1[1].multiplier = apply_node_operation(node, (arg1[1].multiplier, arg2[1]))
     return arg1
 
 
@@ -316,25 +285,12 @@ def _handle_division_nonlinear(visitor, node, arg1, arg2):
     return _GENERAL, ans
 
 
-_exit_node_handlers[DivisionExpression] = {
-    (_CONSTANT, _CONSTANT): _handle_division_constant_constant,
-    (_CONSTANT, _LINEAR): _handle_division_nonlinear,
-    (_CONSTANT, _GENERAL): _handle_division_nonlinear,
-    (_LINEAR, _CONSTANT): _handle_division_ANY_constant,
-    (_LINEAR, _LINEAR): _handle_division_nonlinear,
-    (_LINEAR, _GENERAL): _handle_division_nonlinear,
-    (_GENERAL, _CONSTANT): _handle_division_ANY_constant,
-    (_GENERAL, _LINEAR): _handle_division_nonlinear,
-    (_GENERAL, _GENERAL): _handle_division_nonlinear,
-}
-
 #
 # EXPONENTIATION handlers
 #
 
 
-def _handle_pow_constant_constant(visitor, node, *args):
-    arg1, arg2 = args
+def _handle_pow_constant_constant(visitor, node, arg1, arg2):
     ans = apply_node_operation(node, (arg1[1], arg2[1]))
     if ans.__class__ in native_complex_types:
         ans = complex_number_error(ans, visitor, node)
@@ -365,18 +321,6 @@ def _handle_pow_nonlinear(visitor, node, arg1, arg2):
     return _GENERAL, ans
 
 
-_exit_node_handlers[PowExpression] = {
-    (_CONSTANT, _CONSTANT): _handle_pow_constant_constant,
-    (_CONSTANT, _LINEAR): _handle_pow_nonlinear,
-    (_CONSTANT, _GENERAL): _handle_pow_nonlinear,
-    (_LINEAR, _CONSTANT): _handle_pow_ANY_constant,
-    (_LINEAR, _LINEAR): _handle_pow_nonlinear,
-    (_LINEAR, _GENERAL): _handle_pow_nonlinear,
-    (_GENERAL, _CONSTANT): _handle_pow_ANY_constant,
-    (_GENERAL, _LINEAR): _handle_pow_nonlinear,
-    (_GENERAL, _GENERAL): _handle_pow_nonlinear,
-}
-
 #
 # ABS and UNARY handlers
 #
@@ -396,13 +340,6 @@ def _handle_unary_nonlinear(visitor, node, arg):
     return _GENERAL, ans
 
 
-_exit_node_handlers[UnaryFunctionExpression] = {
-    (_CONSTANT,): _handle_unary_constant,
-    (_LINEAR,): _handle_unary_nonlinear,
-    (_GENERAL,): _handle_unary_nonlinear,
-}
-_exit_node_handlers[AbsExpression] = _exit_node_handlers[UnaryFunctionExpression]
-
 #
 # NAMED EXPRESSION handlers
 #
@@ -421,12 +358,6 @@ def _handle_named_ANY(visitor, node, arg1):
     return _type, arg1.duplicate()
 
 
-_exit_node_handlers[Expression] = {
-    (_CONSTANT,): _handle_named_constant,
-    (_LINEAR,): _handle_named_ANY,
-    (_GENERAL,): _handle_named_ANY,
-}
-
 #
 # EXPR_IF handlers
 #
@@ -457,16 +388,6 @@ def _handle_expr_if_nonlinear(visitor, node, arg1, arg2, arg3):
     return _GENERAL, ans
 
 
-_exit_node_handlers[Expr_ifExpression] = {
-    (i, j, k): _handle_expr_if_nonlinear
-    for i in (_LINEAR, _GENERAL)
-    for j in (_CONSTANT, _LINEAR, _GENERAL)
-    for k in (_CONSTANT, _LINEAR, _GENERAL)
-}
-for j in (_CONSTANT, _LINEAR, _GENERAL):
-    for k in (_CONSTANT, _LINEAR, _GENERAL):
-        _exit_node_handlers[Expr_ifExpression][_CONSTANT, j, k] = _handle_expr_if_const
-
 #
 # Relational expression handlers
 #
@@ -494,14 +415,6 @@ def _handle_equality_general(visitor, node, arg1, arg2):
     return _GENERAL, ans
 
 
-_exit_node_handlers[EqualityExpression] = {
-    (i, j): _handle_equality_general
-    for i in (_CONSTANT, _LINEAR, _GENERAL)
-    for j in (_CONSTANT, _LINEAR, _GENERAL)
-}
-_exit_node_handlers[EqualityExpression][_CONSTANT, _CONSTANT] = _handle_equality_const
-
-
 def _handle_inequality_const(visitor, node, arg1, arg2):
     # It is exceptionally likely that if we get here, one of the
     # arguments is an InvalidNumber
@@ -524,16 +437,6 @@ def _handle_inequality_general(visitor, node, arg1, arg2):
     return _GENERAL, ans
 
 
-_exit_node_handlers[InequalityExpression] = {
-    (i, j): _handle_inequality_general
-    for i in (_CONSTANT, _LINEAR, _GENERAL)
-    for j in (_CONSTANT, _LINEAR, _GENERAL)
-}
-_exit_node_handlers[InequalityExpression][
-    _CONSTANT, _CONSTANT
-] = _handle_inequality_const
-
-
 def _handle_ranged_const(visitor, node, arg1, arg2, arg3):
     # It is exceptionally likely that if we get here, one of the
     # arguments is an InvalidNumber
@@ -561,15 +464,62 @@ def _handle_ranged_general(visitor, node, arg1, arg2, arg3):
     return _GENERAL, ans
 
 
-_exit_node_handlers[RangedExpression] = {
-    (i, j, k): _handle_ranged_general
-    for i in (_CONSTANT, _LINEAR, _GENERAL)
-    for j in (_CONSTANT, _LINEAR, _GENERAL)
-    for k in (_CONSTANT, _LINEAR, _GENERAL)
-}
-_exit_node_handlers[RangedExpression][
-    _CONSTANT, _CONSTANT, _CONSTANT
-] = _handle_ranged_const
+def define_exit_node_handlers(_exit_node_handlers=None):
+    if _exit_node_handlers is None:
+        _exit_node_handlers = {}
+    _exit_node_handlers[NegationExpression] = {
+        None: _handle_negation_ANY,
+        (_CONSTANT,): _handle_negation_constant,
+    }
+    _exit_node_handlers[ProductExpression] = {
+        None: _handle_product_nonlinear,
+        (_CONSTANT, _CONSTANT): _handle_product_constant_constant,
+        (_CONSTANT, _LINEAR): _handle_product_constant_ANY,
+        (_CONSTANT, _GENERAL): _handle_product_constant_ANY,
+        (_LINEAR, _CONSTANT): _handle_product_ANY_constant,
+        (_GENERAL, _CONSTANT): _handle_product_ANY_constant,
+    }
+    _exit_node_handlers[MonomialTermExpression] = _exit_node_handlers[ProductExpression]
+    _exit_node_handlers[DivisionExpression] = {
+        None: _handle_division_nonlinear,
+        (_CONSTANT, _CONSTANT): _handle_division_constant_constant,
+        (_LINEAR, _CONSTANT): _handle_division_ANY_constant,
+        (_GENERAL, _CONSTANT): _handle_division_ANY_constant,
+    }
+    _exit_node_handlers[PowExpression] = {
+        None: _handle_pow_nonlinear,
+        (_CONSTANT, _CONSTANT): _handle_pow_constant_constant,
+        (_LINEAR, _CONSTANT): _handle_pow_ANY_constant,
+        (_GENERAL, _CONSTANT): _handle_pow_ANY_constant,
+    }
+    _exit_node_handlers[UnaryFunctionExpression] = {
+        None: _handle_unary_nonlinear,
+        (_CONSTANT,): _handle_unary_constant,
+    }
+    _exit_node_handlers[AbsExpression] = _exit_node_handlers[UnaryFunctionExpression]
+    _exit_node_handlers[Expression] = {
+        None: _handle_named_ANY,
+        (_CONSTANT,): _handle_named_constant,
+    }
+    _exit_node_handlers[Expr_ifExpression] = {None: _handle_expr_if_nonlinear}
+    for j in (_CONSTANT, _LINEAR, _GENERAL):
+        for k in (_CONSTANT, _LINEAR, _GENERAL):
+            _exit_node_handlers[Expr_ifExpression][
+                _CONSTANT, j, k
+            ] = _handle_expr_if_const
+    _exit_node_handlers[EqualityExpression] = {
+        None: _handle_equality_general,
+        (_CONSTANT, _CONSTANT): _handle_equality_const,
+    }
+    _exit_node_handlers[InequalityExpression] = {
+        None: _handle_inequality_general,
+        (_CONSTANT, _CONSTANT): _handle_inequality_const,
+    }
+    _exit_node_handlers[RangedExpression] = {
+        None: _handle_ranged_general,
+        (_CONSTANT, _CONSTANT, _CONSTANT): _handle_ranged_const,
+    }
+    return _exit_node_handlers
 
 
 class LinearBeforeChildDispatcher(BeforeChildDispatcher):
@@ -704,6 +654,18 @@ def _before_linear(visitor, child):
                     linear[_id] = arg1
             elif arg.__class__ in native_numeric_types:
                 const += arg
+            elif arg.is_variable_type():
+                _id = id(arg)
+                if _id not in var_map:
+                    if arg.fixed:
+                        const += visitor.check_constant(arg.value, arg)
+                        continue
+                    LinearBeforeChildDispatcher._record_var(visitor, arg)
+                    linear[_id] = 1
+                elif _id in linear:
+                    linear[_id] += 1
+                else:
+                    linear[_id] = 1
             else:
                 try:
                     const += visitor.check_constant(visitor.evaluate(arg), arg)
@@ -750,15 +712,17 @@ def _initialize_exit_node_dispatcher(exit_handlers):
     exit_dispatcher = {}
     for cls, handlers in exit_handlers.items():
         for args, fcn in handlers.items():
-            exit_dispatcher[(cls, *args)] = fcn
+            if args is None:
+                exit_dispatcher[cls] = fcn
+            else:
+                exit_dispatcher[(cls, *args)] = fcn
     return exit_dispatcher
 
 
 class LinearRepnVisitor(StreamBasedExpressionVisitor):
     Result = LinearRepn
-    exit_node_handlers = _exit_node_handlers
     exit_node_dispatcher = ExitNodeDispatcher(
-        _initialize_exit_node_dispatcher(_exit_node_handlers)
+        _initialize_exit_node_dispatcher(define_exit_node_handlers())
     )
     expand_nonlinear_products = False
     max_exponential_expansion = 1
diff --git a/pyomo/repn/parameterized_linear.py b/pyomo/repn/parameterized_linear.py
new file mode 100644
index 00000000000..d1295b73e14
--- /dev/null
+++ b/pyomo/repn/parameterized_linear.py
@@ -0,0 +1,395 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import copy
+
+from pyomo.common.collections import ComponentSet
+from pyomo.common.numeric_types import native_numeric_types
+from pyomo.core import Var
+from pyomo.core.expr.logical_expr import _flattened
+from pyomo.core.expr.numeric_expr import (
+    AbsExpression,
+    DivisionExpression,
+    LinearExpression,
+    MonomialTermExpression,
+    NegationExpression,
+    mutable_expression,
+    PowExpression,
+    ProductExpression,
+    SumExpression,
+    UnaryFunctionExpression,
+)
+from pyomo.repn.linear import (
+    ExitNodeDispatcher,
+    _initialize_exit_node_dispatcher,
+    LinearBeforeChildDispatcher,
+    LinearRepn,
+    LinearRepnVisitor,
+)
+from pyomo.repn.util import ExprType
+import pyomo.repn.linear as linear
+
+
+_FIXED = ExprType.FIXED
+_CONSTANT = ExprType.CONSTANT
+_LINEAR = ExprType.LINEAR
+_GENERAL = ExprType.GENERAL
+
+
+def _merge_dict(dest_dict, mult, src_dict):
+    if mult.__class__ not in native_numeric_types or mult != 1:
+        for vid, coef in src_dict.items():
+            if vid in dest_dict:
+                dest_dict[vid] += mult * coef
+            else:
+                dest_dict[vid] = mult * coef
+    else:
+        for vid, coef in src_dict.items():
+            if vid in dest_dict:
+                dest_dict[vid] += coef
+            else:
+                dest_dict[vid] = coef
+
+
+def to_expression(visitor, arg):
+    if arg[0] in (_CONSTANT, _FIXED):
+        return arg[1]
+    else:
+        return arg[1].to_expression(visitor)
+
+
+class ParameterizedLinearRepn(LinearRepn):
+    def __str__(self):
+        return (
+            f"ParameterizedLinearRepn(mult={self.multiplier}, const={self.constant}, "
+            f"linear={self.linear}, nonlinear={self.nonlinear})"
+        )
+
+    def walker_exitNode(self):
+        if self.nonlinear is not None:
+            return _GENERAL, self
+        elif self.linear:
+            return _LINEAR, self
+        elif self.constant.__class__ in native_numeric_types:
+            return _CONSTANT, self.multiplier * self.constant
+        else:
+            return _FIXED, self.multiplier * self.constant
+
+    def to_expression(self, visitor):
+        if self.nonlinear is not None:
+            # We want to start with the nonlinear term (and use
+            # assignment) in case the term is a non-numeric node (like a
+            # relational expression)
+            ans = self.nonlinear
+        else:
+            ans = 0
+        if self.linear:
+            var_map = visitor.var_map
+            with mutable_expression() as e:
+                for vid, coef in self.linear.items():
+                    if coef.__class__ not in native_numeric_types or coef:
+                        e += coef * var_map[vid]
+            if e.nargs() > 1:
+                ans += e
+            elif e.nargs() == 1:
+                ans += e.arg(0)
+        if self.constant.__class__ not in native_numeric_types or self.constant:
+            ans += self.constant
+        if (
+            self.multiplier.__class__ not in native_numeric_types
+            or self.multiplier != 1
+        ):
+            ans *= self.multiplier
+        return ans
+
+    def append(self, other):
+        """Append a child result from acceptChildResult
+
+        Notes
+        -----
+        This method assumes that the operator was "+". It is implemented
+        so that we can directly use a ParameterizedLinearRepn() as a `data` object in
+        the expression walker (thereby allowing us to use the default
+        implementation of acceptChildResult [which calls
+        `data.append()`] and avoid the function call for a custom
+        callback).
+
+        """
+        _type, other = other
+        if _type is _CONSTANT or _type is _FIXED:
+            self.constant += other
+            return
+
+        mult = other.multiplier
+        try:
+            _mult = bool(mult)
+            if not _mult:
+                return
+            if mult == 1:
+                _mult = False
+        except:
+            _mult = True
+
+        const = other.constant
+        try:
+            _const = bool(const)
+        except:
+            _const = True
+
+        if _mult:
+            if _const:
+                self.constant += mult * const
+            if other.linear:
+                _merge_dict(self.linear, mult, other.linear)
+            if other.nonlinear is not None:
+                nl = mult * other.nonlinear
+                if self.nonlinear is None:
+                    self.nonlinear = nl
+                else:
+                    self.nonlinear += nl
+        else:
+            if _const:
+                self.constant += const
+            if other.linear:
+                _merge_dict(self.linear, 1, other.linear)
+            if other.nonlinear is not None:
+                nl = other.nonlinear
+                if self.nonlinear is None:
+                    self.nonlinear = nl
+                else:
+                    self.nonlinear += nl
+
+
+class ParameterizedLinearBeforeChildDispatcher(LinearBeforeChildDispatcher):
+    def __init__(self):
+        super().__init__()
+        self[Var] = self._before_var
+        self[MonomialTermExpression] = self._before_monomial
+        self[LinearExpression] = self._before_linear
+        self[SumExpression] = self._before_general_expression
+
+    @staticmethod
+    def _before_linear(visitor, child):
+        return True, None
+
+    @staticmethod
+    def _before_monomial(visitor, child):
+        return True, None
+
+    @staticmethod
+    def _before_general_expression(visitor, child):
+        return True, None
+
+    @staticmethod
+    def _before_var(visitor, child):
+        _id = id(child)
+        if _id not in visitor.var_map:
+            if child.fixed:
+                return False, (_CONSTANT, visitor.check_constant(child.value, child))
+            if child in visitor.wrt:
+                # pseudo-constant
+                # We aren't treating this Var as a Var for the purposes of this walker
+                return False, (_FIXED, child)
+            # This is a normal situation
+            ParameterizedLinearBeforeChildDispatcher._record_var(visitor, child)
+        ans = visitor.Result()
+        ans.linear[_id] = 1
+        return False, (ExprType.LINEAR, ans)
+
+
+_before_child_dispatcher = ParameterizedLinearBeforeChildDispatcher()
+
+#
+# NEGATION handlers
+#
+
+
+def _handle_negation_pseudo_constant(visitor, node, arg):
+    return (_FIXED, -1 * arg[1])
+
+
+#
+# PRODUCT handlers
+#
+
+
+def _handle_product_constant_constant(visitor, node, arg1, arg2):
+    # [ESJ 5/22/24]: Overriding this handler to exclude the deprecation path for
+    # 0 * nan. It doesn't need overridden when that deprecation path goes away.
+    return _CONSTANT, arg1[1] * arg2[1]
+
+
+def _handle_product_pseudo_constant_constant(visitor, node, arg1, arg2):
+    return _FIXED, arg1[1] * arg2[1]
+
+
+#
+# DIVISION handlers
+#
+
+
+def _handle_division_pseudo_constant_constant(visitor, node, arg1, arg2):
+    return _FIXED, arg1[1] / arg2[1]
+
+
+def _handle_division_ANY_pseudo_constant(visitor, node, arg1, arg2):
+    arg1[1].multiplier = arg1[1].multiplier / arg2[1]
+    return arg1
+
+
+#
+# EXPONENTIATION handlers
+#
+
+
+def _handle_pow_pseudo_constant_constant(visitor, node, arg1, arg2):
+    return _FIXED, to_expression(visitor, arg1) ** to_expression(visitor, arg2)
+
+
+def _handle_pow_nonlinear(visitor, node, arg1, arg2):
+    # ESJ: We override this because we need our own to_expression implementation
+    # if pseudo constants are involved.
+    ans = visitor.Result()
+    ans.nonlinear = to_expression(visitor, arg1) ** to_expression(visitor, arg2)
+    return _GENERAL, ans
+
+
+#
+# ABS and UNARY handlers
+#
+
+
+def _handle_unary_pseudo_constant(visitor, node, arg):
+    # We override this because we can't blindly use apply_node_operation in this case
+    return _FIXED, node.create_node_with_local_data((to_expression(visitor, arg),))
+
+
+def define_exit_node_handlers(exit_node_handlers=None):
+    if exit_node_handlers is None:
+        exit_node_handlers = {}
+    linear.define_exit_node_handlers(exit_node_handlers)
+
+    exit_node_handlers[NegationExpression].update(
+        {(_FIXED,): _handle_negation_pseudo_constant}
+    )
+
+    exit_node_handlers[ProductExpression].update(
+        {
+            (_CONSTANT, _CONSTANT): _handle_product_constant_constant,
+            (_FIXED, _FIXED): _handle_product_pseudo_constant_constant,
+            (_FIXED, _CONSTANT): _handle_product_pseudo_constant_constant,
+            (_CONSTANT, _FIXED): _handle_product_pseudo_constant_constant,
+            (_FIXED, _LINEAR): linear._handle_product_constant_ANY,
+            (_LINEAR, _FIXED): linear._handle_product_ANY_constant,
+            (_FIXED, _GENERAL): linear._handle_product_constant_ANY,
+            (_GENERAL, _FIXED): linear._handle_product_ANY_constant,
+        }
+    )
+
+    exit_node_handlers[MonomialTermExpression].update(
+        exit_node_handlers[ProductExpression]
+    )
+
+    exit_node_handlers[DivisionExpression].update(
+        {
+            (_FIXED, _FIXED): _handle_division_pseudo_constant_constant,
+            (_FIXED, _CONSTANT): _handle_division_pseudo_constant_constant,
+            (_CONSTANT, _FIXED): _handle_division_pseudo_constant_constant,
+            (_LINEAR, _FIXED): _handle_division_ANY_pseudo_constant,
+            (_GENERAL, _FIXED): _handle_division_ANY_pseudo_constant,
+        }
+    )
+
+    exit_node_handlers[PowExpression].update(
+        {
+            (_FIXED, _FIXED): _handle_pow_pseudo_constant_constant,
+            (_FIXED, _CONSTANT): _handle_pow_pseudo_constant_constant,
+            (_CONSTANT, _FIXED): _handle_pow_pseudo_constant_constant,
+            (_LINEAR, _FIXED): _handle_pow_nonlinear,
+            (_FIXED, _LINEAR): _handle_pow_nonlinear,
+            (_GENERAL, _FIXED): _handle_pow_nonlinear,
+            (_FIXED, _GENERAL): _handle_pow_nonlinear,
+        }
+    )
+    exit_node_handlers[UnaryFunctionExpression].update(
+        {(_FIXED,): _handle_unary_pseudo_constant}
+    )
+    exit_node_handlers[AbsExpression] = exit_node_handlers[UnaryFunctionExpression]
+
+    return exit_node_handlers
+
+
+class ParameterizedLinearRepnVisitor(LinearRepnVisitor):
+    Result = ParameterizedLinearRepn
+    exit_node_dispatcher = ExitNodeDispatcher(
+        _initialize_exit_node_dispatcher(define_exit_node_handlers())
+    )
+
+    def __init__(self, subexpression_cache, var_map, var_order, sorter, wrt):
+        super().__init__(subexpression_cache, var_map, var_order, sorter)
+        self.wrt = ComponentSet(_flattened(wrt))
+
+    def beforeChild(self, node, child, child_idx):
+        return _before_child_dispatcher[child.__class__](self, child)
+
+    def _factor_multiplier_into_linear_terms(self, ans, mult):
+        linear = ans.linear
+        zeros = []
+        for vid, coef in linear.items():
+            if coef.__class__ not in native_numeric_types or coef:
+                linear[vid] = mult * coef
+            else:
+                zeros.append(vid)
+        for vid in zeros:
+            del linear[vid]
+        if ans.nonlinear is not None:
+            ans.nonlinear *= mult
+        if ans.constant.__class__ not in native_numeric_types or ans.constant:
+            ans.constant *= mult
+        ans.multiplier = 1
+
+    def finalizeResult(self, result):
+        ans = result[1]
+        if ans.__class__ is self.Result:
+            mult = ans.multiplier
+            if mult.__class__ not in native_numeric_types:
+                # mult is an expression--we should push it back into the other terms
+                self._factor_multiplier_into_linear_terms(ans, mult)
+                return ans
+            if mult == 1:
+                zeros = [
+                    (vid, coef)
+                    for vid, coef in ans.linear.items()
+                    if coef.__class__ in native_numeric_types and not coef
+                ]
+                for vid, coef in zeros:
+                    del ans.linear[vid]
+            elif not mult:
+                # the multiplier has cleared out the entire expression.  Check
+                # if this is suppressing a NaN because we can't clear everything
+                # out if it is
+                if ans.constant != ans.constant or any(
+                    c != c for c in ans.linear.values()
+                ):
+                    # There's a nan in here, so we distribute the 0
+                    self._factor_multiplier_into_linear_terms(ans, mult)
+                    return ans
+                return self.Result()
+            else:
+                # mult not in {0, 1}: factor it into the constant,
+                # linear coefficients, and nonlinear term
+                self._factor_multiplier_into_linear_terms(ans, mult)
+            return ans
+
+        ans = self.Result()
+        assert result[0] in (_CONSTANT, _FIXED)
+        ans.constant = result[1]
+        return ans
diff --git a/pyomo/repn/plugins/__init__.py b/pyomo/repn/plugins/__init__.py
index 56b221d3129..d3804c55106 100644
--- a/pyomo/repn/plugins/__init__.py
+++ b/pyomo/repn/plugins/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/plugins/ampl/__init__.py b/pyomo/repn/plugins/ampl/__init__.py
index 493bc06d9c4..d935056c90b 100644
--- a/pyomo/repn/plugins/ampl/__init__.py
+++ b/pyomo/repn/plugins/ampl/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/plugins/ampl/ampl_.py b/pyomo/repn/plugins/ampl/ampl_.py
index d1a11bf2f38..cc99e9cfdae 100644
--- a/pyomo/repn/plugins/ampl/ampl_.py
+++ b/pyomo/repn/plugins/ampl/ampl_.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -13,8 +13,6 @@
 # AMPL Problem Writer Plugin
 #
 
-__all__ = ['ProblemWriter_nl']
-
 import itertools
 import logging
 import operator
@@ -35,7 +33,7 @@
 from pyomo.core.base import (
     SymbolMap,
     NameLabeler,
-    _ExpressionData,
+    NamedExpressionData,
     SortComponents,
     var,
     param,
@@ -170,11 +168,11 @@ def _build_op_template():
     _op_template[EXPR.EqualityExpression] = "o24{C}\n"
     _op_comment[EXPR.EqualityExpression] = "\t#eq"
 
-    _op_template[var._VarData] = "v%d{C}\n"
-    _op_comment[var._VarData] = "\t#%s"
+    _op_template[var.VarData] = "v%d{C}\n"
+    _op_comment[var.VarData] = "\t#%s"
 
-    _op_template[param._ParamData] = "n%r{C}\n"
-    _op_comment[param._ParamData] = ""
+    _op_template[param.ParamData] = "n%r{C}\n"
+    _op_comment[param.ParamData] = ""
 
     _op_template[NumericConstant] = "n%r{C}\n"
     _op_comment[NumericConstant] = ""
@@ -726,7 +724,7 @@ def _print_nonlinear_terms_NL(self, exp):
                 self._print_nonlinear_terms_NL(exp.arg(0))
                 self._print_nonlinear_terms_NL(exp.arg(1))
 
-            elif isinstance(exp, (_ExpressionData, IIdentityExpression)):
+            elif isinstance(exp, (NamedExpressionData, IIdentityExpression)):
                 self._print_nonlinear_terms_NL(exp.expr)
 
             else:
@@ -735,24 +733,24 @@ def _print_nonlinear_terms_NL(self, exp):
                     % (exp_type)
                 )
 
-        elif isinstance(exp, (var._VarData, IVariable)) and (not exp.is_fixed()):
+        elif isinstance(exp, (var.VarData, IVariable)) and (not exp.is_fixed()):
             # (self._output_fixed_variable_bounds or
             if not self._symbolic_solver_labels:
                 OUTPUT.write(
-                    self._op_string[var._VarData]
+                    self._op_string[var.VarData]
                     % (self.ampl_var_id[self._varID_map[id(exp)]])
                 )
             else:
                 OUTPUT.write(
-                    self._op_string[var._VarData]
+                    self._op_string[var.VarData]
                     % (
                         self.ampl_var_id[self._varID_map[id(exp)]],
                         self._name_labeler(exp),
                     )
                 )
 
-        elif isinstance(exp, param._ParamData):
-            OUTPUT.write(self._op_string[param._ParamData] % (value(exp)))
+        elif isinstance(exp, param.ParamData):
+            OUTPUT.write(self._op_string[param.ParamData] % (value(exp)))
 
         elif isinstance(exp, NumericConstant) or exp.is_fixed():
             OUTPUT.write(self._op_string[NumericConstant] % (value(exp)))
diff --git a/pyomo/repn/plugins/baron_writer.py b/pyomo/repn/plugins/baron_writer.py
index 0d684fcd1d2..ab673b0c1c3 100644
--- a/pyomo/repn/plugins/baron_writer.py
+++ b/pyomo/repn/plugins/baron_writer.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -174,15 +174,26 @@ def _monomial_to_string(self, node):
                 return self.smap.getSymbol(var)
         return ftoa(const, True) + '*' + self.smap.getSymbol(var)
 
+    def _var_to_string(self, node):
+        if node.is_fixed():
+            return ftoa(node.value, True)
+        self.variables.add(id(node))
+        return self.smap.getSymbol(node)
+
     def _linear_to_string(self, node):
         values = [
             (
                 self._monomial_to_string(arg)
-                if (
-                    arg.__class__ is EXPR.MonomialTermExpression
-                    and not arg.arg(1).is_fixed()
+                if arg.__class__ is EXPR.MonomialTermExpression
+                else (
+                    ftoa(arg)
+                    if arg.__class__ in native_numeric_types
+                    else (
+                        self._var_to_string(arg)
+                        if arg.is_variable_type()
+                        else ftoa(value(arg), True)
+                    )
                 )
-                else ftoa(value(arg))
             )
             for arg in node.args
         ]
diff --git a/pyomo/repn/plugins/cpxlp.py b/pyomo/repn/plugins/cpxlp.py
index cdcb4b42c3b..45f4279f8fe 100644
--- a/pyomo/repn/plugins/cpxlp.py
+++ b/pyomo/repn/plugins/cpxlp.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -60,7 +60,7 @@ def __init__(self):
         # The LP writer tracks which variables are
         # referenced in constraints, so that a user does not end up with a
         # zillion "unreferenced variables" warning messages.
-        # This dictionary maps id(_VarData) -> _VarData.
+        # This dictionary maps id(VarData) -> VarData.
         self._referenced_variable_ids = {}
 
         # Per ticket #4319, we are using %.17g, which mocks the
@@ -374,7 +374,7 @@ def _print_expr_canonical(
 
     def printSOS(self, symbol_map, labeler, variable_symbol_map, soscondata, output):
         """
-        Prints the SOS constraint associated with the _SOSConstraintData object
+        Prints the SOS constraint associated with the SOSConstraintData object
         """
         sos_template_string = self.sos_template_string
 
diff --git a/pyomo/repn/plugins/gams_writer.py b/pyomo/repn/plugins/gams_writer.py
index 719839fc8dd..a0f407d7952 100644
--- a/pyomo/repn/plugins/gams_writer.py
+++ b/pyomo/repn/plugins/gams_writer.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -183,7 +183,16 @@ def _linear_to_string(self, node):
             (
                 self._monomial_to_string(arg)
                 if arg.__class__ is EXPR.MonomialTermExpression
-                else ftoa(arg, True)
+                else (
+                    ftoa(arg, True)
+                    if arg.__class__ in native_numeric_types
+                    else (
+                        self.smap.getSymbol(arg)
+                        if arg.is_variable_type()
+                        and (not arg.fixed or self.output_fixed_variables)
+                        else ftoa(value(arg), True)
+                    )
+                )
             )
             for arg in node.args
         ]
diff --git a/pyomo/repn/plugins/lp_writer.py b/pyomo/repn/plugins/lp_writer.py
index be718ee696e..814f79a4eb9 100644
--- a/pyomo/repn/plugins/lp_writer.py
+++ b/pyomo/repn/plugins/lp_writer.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -458,13 +458,13 @@ def write(self, model):
                     addSymbol(con, label)
                     ostream.write(f'\n{label}:\n')
                     self.write_expression(ostream, repn, False)
-                    ostream.write(f'>= {(lb - offset)!r}\n')
+                    ostream.write(f'>= {(lb - offset)!s}\n')
                 elif lb == ub:
                     label = f'c_e_{symbol}_'
                     addSymbol(con, label)
                     ostream.write(f'\n{label}:\n')
                     self.write_expression(ostream, repn, False)
-                    ostream.write(f'= {(lb - offset)!r}\n')
+                    ostream.write(f'= {(lb - offset)!s}\n')
                 else:
                     # We will need the constraint body twice.  Generate
                     # in a buffer so we only have to do that once.
@@ -476,18 +476,18 @@ def write(self, model):
                     addSymbol(con, label)
                     ostream.write(f'\n{label}:\n')
                     ostream.write(buf)
-                    ostream.write(f'>= {(lb - offset)!r}\n')
+                    ostream.write(f'>= {(lb - offset)!s}\n')
                     label = f'r_u_{symbol}_'
                     aliasSymbol(con, label)
                     ostream.write(f'\n{label}:\n')
                     ostream.write(buf)
-                    ostream.write(f'<= {(ub - offset)!r}\n')
+                    ostream.write(f'<= {(ub - offset)!s}\n')
             elif ub is not None:
                 label = f'c_u_{symbol}_'
                 addSymbol(con, label)
                 ostream.write(f'\n{label}:\n')
                 self.write_expression(ostream, repn, False)
-                ostream.write(f'<= {(ub - offset)!r}\n')
+                ostream.write(f'<= {(ub - offset)!s}\n')
 
         if with_debug_timing:
             # report the last constraint
@@ -527,8 +527,8 @@ def write(self, model):
             # Note: Var.bounds guarantees the values are either (finite)
             # native_numeric_types or None
             lb, ub = v.bounds
-            lb = '-inf' if lb is None else repr(lb)
-            ub = '+inf' if ub is None else repr(ub)
+            lb = '-inf' if lb is None else str(lb)
+            ub = '+inf' if ub is None else str(ub)
             ostream.write(f"\n   {lb} <= {v_symbol} <= {ub}")
 
         if integer_vars:
@@ -565,7 +565,7 @@ def write(self, model):
                 for v, w in getattr(soscon, 'get_items', soscon.items)():
                     if w.__class__ not in int_float:
                         w = float(f)
-                    ostream.write(f"  {getSymbol(v)}:{w!r}\n")
+                    ostream.write(f"  {getSymbol(v)}:{w!s}\n")
 
         ostream.write("\nend\n")
 
@@ -584,9 +584,9 @@ def write_expression(self, ostream, expr, is_objective):
                 expr.linear.items(), key=lambda x: getVarOrder(x[0])
             ):
                 if coef < 0:
-                    ostream.write(f'{coef!r} {getSymbol(getVar(vid))}\n')
+                    ostream.write(f'{coef!s} {getSymbol(getVar(vid))}\n')
                 else:
-                    ostream.write(f'+{coef!r} {getSymbol(getVar(vid))}\n')
+                    ostream.write(f'+{coef!s} {getSymbol(getVar(vid))}\n')
 
         quadratic = getattr(expr, 'quadratic', None)
         if quadratic:
@@ -605,9 +605,9 @@ def _normalize_constraint(data):
                     col = c1, c2
                     sym = f' {getSymbol(getVar(vid1))} * {getSymbol(getVar(vid2))}\n'
                 if coef < 0:
-                    return col, repr(coef) + sym
+                    return col, str(coef) + sym
                 else:
-                    return col, '+' + repr(coef) + sym
+                    return col, f'+{coef!s}{sym}'
 
             if is_objective:
                 #
diff --git a/pyomo/repn/plugins/mps.py b/pyomo/repn/plugins/mps.py
index f40c7666278..e1a0d2187fc 100644
--- a/pyomo/repn/plugins/mps.py
+++ b/pyomo/repn/plugins/mps.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -62,7 +62,7 @@ def __init__(self, int_marker=False):
         # referenced in constraints, so that one doesn't end up with a
         # zillion "unreferenced variables" warning messages. stored at
         # the object level to avoid additional method arguments.
-        # dictionary of id(_VarData)->_VarData.
+        # dictionary of id(VarData)->VarData.
         self._referenced_variable_ids = {}
 
         # Keven Hunter made a nice point about using %.16g in his attachment
diff --git a/pyomo/repn/plugins/nl_writer.py b/pyomo/repn/plugins/nl_writer.py
index 2d5eae151b0..8fc82d21d30 100644
--- a/pyomo/repn/plugins/nl_writer.py
+++ b/pyomo/repn/plugins/nl_writer.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -11,10 +11,12 @@
 
 import ctypes
 import logging
+import math
+import operator
 import os
 from collections import deque, defaultdict, namedtuple
 from contextlib import nullcontext
-from itertools import filterfalse, product
+from itertools import filterfalse, product, chain
 from math import log10 as _log10
 from operator import itemgetter, attrgetter, setitem
 
@@ -69,15 +71,11 @@
     minimize,
 )
 from pyomo.core.base.component import ActiveComponent
-from pyomo.core.base.constraint import _ConstraintData
-from pyomo.core.base.expression import ScalarExpression, _GeneralExpressionData
-from pyomo.core.base.objective import (
-    ScalarObjective,
-    _GeneralObjectiveData,
-    _ObjectiveData,
-)
+from pyomo.core.base.constraint import ConstraintData
+from pyomo.core.base.expression import ScalarExpression, ExpressionData
+from pyomo.core.base.objective import ScalarObjective, ObjectiveData
 from pyomo.core.base.suffix import SuffixFinder
-from pyomo.core.base.var import _VarData
+from pyomo.core.base.var import VarData
 import pyomo.core.kernel as kernel
 from pyomo.core.pyomoobject import PyomoObject
 from pyomo.opt import WriterFactory
@@ -113,6 +111,7 @@
 TOL = 1e-8
 inf = float('inf')
 minus_inf = -inf
+allowable_binary_var_bounds = {(0, 0), (0, 1), (1, 1)}
 
 _CONSTANT = ExprType.CONSTANT
 _MONOMIAL = ExprType.MONOMIAL
@@ -129,17 +128,17 @@ class NLWriterInfo(object):
 
     Attributes
     ----------
-    variables: List[_VarData]
+    variables: List[VarData]
 
         The list of (unfixed) Pyomo model variables in the order written
         to the NL file
 
-    constraints: List[_ConstraintData]
+    constraints: List[ConstraintData]
 
         The list of (active) Pyomo model constraints in the order written
         to the NL file
 
-    objectives: List[_ObjectiveData]
+    objectives: List[ObjectiveData]
 
         The list of (active) Pyomo model objectives in the order written
         to the NL file
@@ -162,10 +161,10 @@ class NLWriterInfo(object):
         file in the same order as the :py:attr:`variables` and generated
         .col file.
 
-    eliminated_vars: List[Tuple[_VarData, NumericExpression]]
+    eliminated_vars: List[Tuple[VarData, NumericExpression]]
 
         The list of variables in the model that were eliminated by the
-        presolve.  Each entry is a 2-tuple of (:py:class:`_VarData`,
+        presolve.  Each entry is a 2-tuple of (:py:class:`VarData`,
         :py:class`NumericExpression`|`float`).  The list is in the
         necessary order for correct evaluation (i.e., all variables
         appearing in the expression must either have been sent to the
@@ -214,7 +213,7 @@ class NLWriter(object):
     CONFIG.declare(
         'skip_trivial_constraints',
         ConfigValue(
-            default=False,
+            default=True,
             domain=bool,
             description='Skip writing constraints whose body is constant',
         ),
@@ -338,6 +337,9 @@ def __call__(self, model, filename, solver_capability, io_options):
         config.scale_model = False
         config.linear_presolve = False
 
+        # just for backwards compatibility
+        config.skip_trivial_constraints = False
+
         if config.symbolic_solver_labels:
             _open = lambda fname: open(fname, 'w')
         else:
@@ -346,6 +348,18 @@ def __call__(self, model, filename, solver_capability, io_options):
             row_fname
         ) as ROWFILE, _open(col_fname) as COLFILE:
             info = self.write(model, FILE, ROWFILE, COLFILE, config=config)
+        if not info.variables:
+            # This exception is included for compatibility with the
+            # original NL writer v1.
+            os.remove(filename)
+            if config.symbolic_solver_labels:
+                os.remove(row_fname)
+                os.remove(col_fname)
+            raise ValueError(
+                "No variables appear in the Pyomo model constraints or"
+                " objective. This is not supported by the NL file interface"
+            )
+
         # Historically, the NL writer communicated the external function
         # libraries back to the ASL interface through the PYOMO_AMPLFUNC
         # environment variable.
@@ -357,7 +371,9 @@ def __call__(self, model, filename, solver_capability, io_options):
         return filename, symbol_map
 
     @document_kwargs_from_configdict(CONFIG)
-    def write(self, model, ostream, rowstream=None, colstream=None, **options):
+    def write(
+        self, model, ostream, rowstream=None, colstream=None, **options
+    ) -> NLWriterInfo:
         """Write a model in NL format.
 
         Returns
@@ -424,6 +440,7 @@ def store(self, obj, val):
         self.values[obj] = val
 
     def compile(self, column_order, row_order, obj_order, model_id):
+        var_con_obj = {Var, Constraint, Objective}
         missing_component_data = ComponentSet()
         unknown_data = ComponentSet()
         queue = [self.values.items()]
@@ -449,18 +466,20 @@ def compile(self, column_order, row_order, obj_order, model_id):
                     self.obj[obj_order[_id]] = val
                 elif _id == model_id:
                     self.prob[0] = val
-                elif isinstance(obj, (_VarData, _ConstraintData, _ObjectiveData)):
-                    missing_component_data.add(obj)
-                elif isinstance(obj, (Var, Constraint, Objective)):
-                    # Expand this indexed component to store the
-                    # individual ComponentDatas, but ONLY if the
-                    # component data is not in the original dictionary
-                    # of values that we extracted from the Suffixes
-                    queue.append(
-                        product(
-                            filterfalse(self.values.__contains__, obj.values()), (val,)
+                elif getattr(obj, 'ctype', None) in var_con_obj:
+                    if obj.is_indexed():
+                        # Expand this indexed component to store the
+                        # individual ComponentDatas, but ONLY if the
+                        # component data is not in the original dictionary
+                        # of values that we extracted from the Suffixes
+                        queue.append(
+                            product(
+                                filterfalse(self.values.__contains__, obj.values()),
+                                (val,),
+                            )
                         )
-                    )
+                    else:
+                        missing_component_data.add(obj)
                 else:
                     unknown_data.add(obj)
         if missing_component_data:
@@ -525,15 +544,15 @@ def __init__(self, ostream, rowstream, colstream, config):
         else:
             self.template = text_nl_template
         self.subexpression_cache = {}
-        self.subexpression_order = []
+        self.subexpression_order = None  # set to [] later
         self.external_functions = {}
         self.used_named_expressions = set()
         self.var_map = {}
+        self.var_id_to_nl_map = {}
         self.sorter = FileDeterminism_to_SortComponents(config.file_determinism)
         self.visitor = AMPLRepnVisitor(
             self.template,
             self.subexpression_cache,
-            self.subexpression_order,
             self.external_functions,
             self.var_map,
             self.used_named_expressions,
@@ -603,6 +622,7 @@ def write(self, model):
         ostream = self.ostream
         linear_presolve = self.config.linear_presolve
 
+        nl_map = self.var_id_to_nl_map
         var_map = self.var_map
         initialize_var_map_from_column_order(model, self.config, var_map)
         timer.toc('Initialized column order', level=logging.DEBUG)
@@ -683,8 +703,7 @@ def write(self, model):
         objectives.extend(linear_objs)
         n_objs = len(objectives)
 
-        constraints = []
-        linear_cons = []
+        all_constraints = []
         n_ranges = 0
         n_equality = 0
         n_complementarity_nonlin = 0
@@ -721,22 +740,7 @@ def write(self, model):
                     ub = ub * scale
                 if scale < 0:
                     lb, ub = ub, lb
-            if expr_info.nonlinear:
-                constraints.append((con, expr_info, lb, ub))
-            elif expr_info.linear:
-                linear_cons.append((con, expr_info, lb, ub))
-            elif not self.config.skip_trivial_constraints:
-                linear_cons.append((con, expr_info, lb, ub))
-            else:  # constant constraint and skip_trivial_constraints
-                c = expr_info.const
-                if (lb is not None and lb - c > TOL) or (
-                    ub is not None and ub - c < -TOL
-                ):
-                    raise InfeasibleConstraintException(
-                        "model contains a trivially infeasible "
-                        f"constraint '{con.name}' (fixed body value "
-                        f"{c} outside bounds [{lb}, {ub}])."
-                    )
+            all_constraints.append((con, expr_info, lb, ub))
             if linear_presolve:
                 con_id = id(con)
                 if not expr_info.nonlinear and lb == ub and lb is not None:
@@ -747,28 +751,68 @@ def write(self, model):
             # report the last constraint
             timer.toc('Constraint %s', last_parent, level=logging.DEBUG)
         else:
-            timer.toc('Processed %s constraints', len(constraints))
+            timer.toc('Processed %s constraints', len(all_constraints))
+
+        # We have identified all the external functions (resolving them
+        # by name).  Now we may need to resolve the function by the
+        # (local) FID, which we know is indexed by integers starting at
+        # 0.  We will convert the dict to a list for efficient lookup.
+        self.external_functions = list(self.external_functions.values())
 
         # This may fetch more bounds than needed, but only in the cases
         # where variables were completely eliminated while walking the
         # expressions, or when users provide superfluous variables in
         # the column ordering.
         var_bounds = {_id: v.bounds for _id, v in var_map.items()}
+        var_values = {_id: v.value for _id, v in var_map.items()}
 
         eliminated_cons, eliminated_vars = self._linear_presolve(
-            comp_by_linear_var, lcon_by_linear_nnz, var_bounds
+            comp_by_linear_var, lcon_by_linear_nnz, var_bounds, var_values
         )
         del comp_by_linear_var
         del lcon_by_linear_nnz
 
-        # Order the constraints, moving all nonlinear constraints to
-        # the beginning
-        n_nonlinear_cons = len(constraints)
+        # Note: defer categorizing constraints until after presolve, as
+        # the presolver could result in nonlinear constraints becoming
+        # linear (or trivial)
+        constraints = []
+        linear_cons = []
         if eliminated_cons:
             _removed = eliminated_cons.__contains__
-            constraints.extend(filterfalse(lambda c: _removed(id(c[0])), linear_cons))
+            _constraints = filterfalse(lambda c: _removed(id(c[0])), all_constraints)
         else:
-            constraints.extend(linear_cons)
+            _constraints = all_constraints
+        for info in _constraints:
+            expr_info = info[1]
+            if expr_info.nonlinear:
+                nl, args = expr_info.nonlinear
+                if any(vid not in nl_map for vid in args):
+                    constraints.append(info)
+                    continue
+                expr_info.const += _evaluate_constant_nl(
+                    nl % tuple(nl_map[i] for i in args), self.external_functions
+                )
+                expr_info.nonlinear = None
+            if expr_info.linear:
+                linear_cons.append(info)
+            elif not self.config.skip_trivial_constraints:
+                linear_cons.append(info)
+            else:  # constant constraint and skip_trivial_constraints
+                c = expr_info.const
+                con, expr_info, lb, ub = info
+                if (lb is not None and lb - c > TOL) or (
+                    ub is not None and ub - c < -TOL
+                ):
+                    raise InfeasibleConstraintException(
+                        "model contains a trivially infeasible "
+                        f"constraint '{con.name}' (fixed body value "
+                        f"{c} outside bounds [{lb}, {ub}])."
+                    )
+
+        # Order the constraints, moving all nonlinear constraints to
+        # the beginning
+        n_nonlinear_cons = len(constraints)
+        constraints.extend(linear_cons)
         n_cons = len(constraints)
 
         #
@@ -781,7 +825,7 @@ def write(self, model):
 
         # Filter out any unused named expressions
         self.subexpression_order = list(
-            filter(self.used_named_expressions.__contains__, self.subexpression_order)
+            filter(self.used_named_expressions.__contains__, self.subexpression_cache)
         )
 
         # linear contribution by (constraint, objective, variable) component.
@@ -803,10 +847,7 @@ def write(self, model):
         # We need to categorize the named subexpressions first so that
         # we know their linear / nonlinear vars when we encounter them
         # in constraints / objectives
-        self._categorize_vars(
-            map(self.subexpression_cache.__getitem__, self.subexpression_order),
-            linear_by_comp,
-        )
+        self._categorize_vars(self.subexpression_cache.values(), linear_by_comp)
         n_subexpressions = self._count_subexpression_occurrences()
         obj_vars_linear, obj_vars_nonlinear, obj_nnz_by_var = self._categorize_vars(
             objectives, linear_by_comp
@@ -830,6 +871,7 @@ def write(self, model):
                     if _id not in var_map:
                         var_map[_id] = _v
                         var_bounds[_id] = _v.bounds
+                        var_values[_id] = _v.value
                     con_vars_nonlinear.add(_id)
 
         con_nnz = sum(con_nnz_by_var.values())
@@ -854,13 +896,6 @@ def write(self, model):
         con_vars = con_vars_linear | con_vars_nonlinear
         all_vars = con_vars | obj_vars
         n_vars = len(all_vars)
-        if n_vars < 1:
-            # TODO: Remove this.  This exception is included for
-            # compatibility with the original NL writer v1.
-            raise ValueError(
-                "No variables appear in the Pyomo model constraints or"
-                " objective. This is not supported by the NL file interface"
-            )
 
         continuous_vars = set()
         binary_vars = set()
@@ -872,7 +907,12 @@ def write(self, model):
             elif v.is_binary():
                 binary_vars.add(_id)
             elif v.is_integer():
-                integer_vars.add(_id)
+                # Note: integer variables whose bounds are in {0, 1}
+                # should be classified as binary
+                if var_bounds[_id] in allowable_binary_var_bounds:
+                    binary_vars.add(_id)
+                else:
+                    integer_vars.add(_id)
             else:
                 raise ValueError(
                     f"Variable '{v.name}' has a domain that is not Real, "
@@ -1026,8 +1066,8 @@ def write(self, model):
             row_comments = [f'\t#{lbl}' for lbl in row_labels]
             col_labels = [labeler(var_map[_id]) for _id in variables]
             col_comments = [f'\t#{lbl}' for lbl in col_labels]
-            self.var_id_to_nl = {
-                _id: f'v{var_idx}{col_comments[var_idx]}'
+            id2nl = {
+                _id: f'v{var_idx}{col_comments[var_idx]}\n'
                 for var_idx, _id in enumerate(variables)
             }
             # Write out the .row and .col data
@@ -1040,11 +1080,12 @@ def write(self, model):
         else:
             row_labels = row_comments = [''] * (n_cons + n_objs)
             col_labels = col_comments = [''] * len(variables)
-            self.var_id_to_nl = {
-                _id: f"v{var_idx}" for var_idx, _id in enumerate(variables)
-            }
+            id2nl = {_id: f"v{var_idx}\n" for var_idx, _id in enumerate(variables)}
 
-        _vmap = self.var_id_to_nl
+        if nl_map:
+            nl_map.update(id2nl)
+        else:
+            self.var_id_to_nl_map = nl_map = id2nl
         if scale_model:
             template = self.template
             objective_scaling = [scaling_cache[id(info[0])] for info in objectives]
@@ -1064,16 +1105,42 @@ def write(self, model):
                 if ub is not None:
                     ub *= scale
                 var_bounds[_id] = lb, ub
-                # Update _vmap to output scaled variables in NL expressions
-                _vmap[_id] = (
-                    template.division + _vmap[_id] + '\n' + template.const % scale
-                ).rstrip()
+                # Update nl_map to output scaled variables in NL expressions
+                nl_map[_id] = template.division + nl_map[_id] + template.const % scale
 
         # Update any eliminated variables to point to the (potentially
         # scaled) substituted variables
-        for _id, expr_info in eliminated_vars.items():
+        for _id, expr_info in list(eliminated_vars.items()):
             nl, args, _ = expr_info.compile_repn(visitor)
-            _vmap[_id] = nl.rstrip() % tuple(_vmap[_id] for _id in args)
+            for _i in args:
+                # It is possible that the eliminated variable could
+                # reference another variable that is no longer part of
+                # the model and therefore does not have a nl_map entry.
+                # This can happen when there is an underdetermined
+                # independent linear subsystem and the presolve removed
+                # all the constraints from the subsystem.  Because the
+                # free variables in the subsystem are not referenced
+                # anywhere else in the model, they are not part of the
+                # `variables` list.  Implicitly "fix" it to an arbitrary
+                # valid value from the presolved domain (see #3192).
+                if _i not in nl_map:
+                    lb, ub = var_bounds[_i]
+                    if lb is None:
+                        lb = -inf
+                    if ub is None:
+                        ub = inf
+                    if lb <= 0 <= ub:
+                        val = 0
+                    else:
+                        val = lb if abs(lb) < abs(ub) else ub
+                    eliminated_vars[_i] = AMPLRepn(val, {}, None)
+                    nl_map[_i] = expr_info.compile_repn(visitor)[0]
+                    logger.warning(
+                        "presolve identified an underdetermined independent "
+                        "linear subsystem that was removed from the model.  "
+                        f"Setting '{var_map[_i]}' == {val}"
+                    )
+            nl_map[_id] = nl % tuple(nl_map[_i] for _i in args)
 
         r_lines = [None] * n_cons
         for idx, (con, expr_info, lb, ub) in enumerate(constraints):
@@ -1083,17 +1150,17 @@ def write(self, model):
                     r_lines[idx] = "3"
                 else:
                     # _type = 4  # L == c == U
-                    r_lines[idx] = f"4 {lb - expr_info.const!r}"
+                    r_lines[idx] = f"4 {lb - expr_info.const!s}"
                     n_equality += 1
             elif lb is None:
                 # _type = 1  # c <= U
-                r_lines[idx] = f"1 {ub - expr_info.const!r}"
+                r_lines[idx] = f"1 {ub - expr_info.const!s}"
             elif ub is None:
                 # _type = 2  # L <= c
-                r_lines[idx] = f"2 {lb - expr_info.const!r}"
+                r_lines[idx] = f"2 {lb - expr_info.const!s}"
             else:
                 # _type = 0  # L <= c <= U
-                r_lines[idx] = f"0 {lb - expr_info.const!r} {ub - expr_info.const!r}"
+                r_lines[idx] = f"0 {lb - expr_info.const!s} {ub - expr_info.const!s}"
                 n_ranges += 1
             expr_info.const = 0
             # FIXME: this is a HACK to be compatible with the NLv1
@@ -1239,8 +1306,8 @@ def write(self, model):
                 len(linear_binary_vars),
                 len(linear_integer_vars),
                 len(both_vars_nonlinear.intersection(discrete_vars)),
-                len(con_vars_nonlinear.intersection(discrete_vars)),
-                len(obj_vars_nonlinear.intersection(discrete_vars)),
+                len(con_only_nonlinear_vars.intersection(discrete_vars)),
+                len(obj_only_nonlinear_vars.intersection(discrete_vars)),
             )
         )
         #
@@ -1272,7 +1339,7 @@ def write(self, model):
         # "F" lines (external function definitions)
         #
         amplfunc_libraries = set()
-        for fid, fcn in sorted(self.external_functions.values()):
+        for fid, fcn in self.external_functions:
             amplfunc_libraries.add(fcn._library)
             ostream.write("F%d 1 -1 %s\n" % (fid, fcn._function))
 
@@ -1308,7 +1375,7 @@ def write(self, model):
                 ostream.write(f"S{_field|_float} {len(_vals)} {name}\n")
                 # Note: _SuffixData.compile() guarantees the value is int/float
                 ostream.write(
-                    ''.join(f"{_id} {_vals[_id]!r}\n" for _id in sorted(_vals))
+                    ''.join(f"{_id} {_vals[_id]!s}\n" for _id in sorted(_vals))
                 )
 
         #
@@ -1418,7 +1485,7 @@ def write(self, model):
                 ostream.write(f"d{len(data.con)}\n")
                 # Note: _SuffixData.compile() guarantees the value is int/float
                 ostream.write(
-                    ''.join(f"{_id} {data.con[_id]!r}\n" for _id in sorted(data.con))
+                    ''.join(f"{_id} {data.con[_id]!s}\n" for _id in sorted(data.con))
                 )
 
         #
@@ -1426,7 +1493,7 @@ def write(self, model):
         #
         _init_lines = [
             (var_idx, val if val.__class__ in int_float else float(val))
-            for var_idx, val in enumerate(var_map[_id].value for _id in variables)
+            for var_idx, val in enumerate(map(var_values.__getitem__, variables))
             if val is not None
         ]
         if scale_model:
@@ -1440,7 +1507,7 @@ def write(self, model):
         )
         ostream.write(
             ''.join(
-                f'{var_idx} {val!r}{col_comments[var_idx]}\n'
+                f'{var_idx} {val!s}{col_comments[var_idx]}\n'
                 for var_idx, val in _init_lines
             )
         )
@@ -1481,13 +1548,13 @@ def write(self, model):
                 if lb is None:  # unbounded
                     ostream.write(f"3{col_comments[var_idx]}\n")
                 else:  # ==
-                    ostream.write(f"4 {lb!r}{col_comments[var_idx]}\n")
+                    ostream.write(f"4 {lb!s}{col_comments[var_idx]}\n")
             elif lb is None:  # var <= ub
-                ostream.write(f"1 {ub!r}{col_comments[var_idx]}\n")
+                ostream.write(f"1 {ub!s}{col_comments[var_idx]}\n")
             elif ub is None:  # lb <= body
-                ostream.write(f"2 {lb!r}{col_comments[var_idx]}\n")
+                ostream.write(f"2 {lb!s}{col_comments[var_idx]}\n")
             else:  # lb <= body <= ub
-                ostream.write(f"0 {lb!r} {ub!r}{col_comments[var_idx]}\n")
+                ostream.write(f"0 {lb!s} {ub!s}{col_comments[var_idx]}\n")
 
         #
         # "k" lines (column offsets in Jacobian NNZ)
@@ -1522,7 +1589,7 @@ def write(self, model):
                     linear[_id] /= scaling_cache[_id]
             ostream.write(f'J{row_idx} {len(linear)}{row_comments[row_idx]}\n')
             for _id in sorted(linear, key=column_order.__getitem__):
-                ostream.write(f'{column_order[_id]} {linear[_id]!r}\n')
+                ostream.write(f'{column_order[_id]} {linear[_id]!s}\n')
 
         #
         # "G" lines (non-empty terms in the Objective)
@@ -1538,7 +1605,7 @@ def write(self, model):
                     linear[_id] /= scaling_cache[_id]
             ostream.write(f'G{obj_idx} {len(linear)}{row_comments[obj_idx + n_cons]}\n')
             for _id in sorted(linear, key=column_order.__getitem__):
-                ostream.write(f'{column_order[_id]} {linear[_id]!r}\n')
+                ostream.write(f'{column_order[_id]} {linear[_id]!s}\n')
 
         # Generate the return information
         eliminated_vars = [
@@ -1647,12 +1714,13 @@ def _categorize_vars(self, comp_list, linear_by_comp):
                     expr_info.linear = dict.fromkeys(nonlinear_vars, 0)
                 all_nonlinear_vars.update(nonlinear_vars)
 
-            # Update the count of components that each variable appears in
-            for v in expr_info.linear:
-                if v in nnz_by_var:
-                    nnz_by_var[v] += 1
-                else:
-                    nnz_by_var[v] = 1
+            if expr_info.linear:
+                # Update the count of components that each variable appears in
+                for v in expr_info.linear:
+                    if v in nnz_by_var:
+                        nnz_by_var[v] += 1
+                    else:
+                        nnz_by_var[v] = 1
             # Record all nonzero variable ids for this component
             linear_by_comp[id(comp_info[0])] = expr_info.linear
         # Linear models (or objectives) are common.  Avoid the set
@@ -1692,7 +1760,9 @@ def _count_subexpression_occurrences(self):
                 n_subexpressions[0] += 1
         return n_subexpressions
 
-    def _linear_presolve(self, comp_by_linear_var, lcon_by_linear_nnz, var_bounds):
+    def _linear_presolve(
+        self, comp_by_linear_var, lcon_by_linear_nnz, var_bounds, var_values
+    ):
         eliminated_vars = {}
         eliminated_cons = set()
         if not self.config.linear_presolve:
@@ -1713,6 +1783,7 @@ def _linear_presolve(self, comp_by_linear_var, lcon_by_linear_nnz, var_bounds):
         var_map = self.var_map
         substitutions_by_linear_var = defaultdict(set)
         template = self.template
+        nl_map = self.var_id_to_nl_map
         one_var = lcon_by_linear_nnz[1]
         two_var = lcon_by_linear_nnz[2]
         while 1:
@@ -1722,6 +1793,7 @@ def _linear_presolve(self, comp_by_linear_var, lcon_by_linear_nnz, var_bounds):
                 b, _ = var_bounds[_id]
                 logger.debug("NL presolve: bounds fixed %s := %s", var_map[_id], b)
                 eliminated_vars[_id] = AMPLRepn(b, {}, None)
+                nl_map[_id] = template.const % b
             elif one_var:
                 con_id, info = one_var.popitem()
                 expr_info, lb = info
@@ -1731,6 +1803,7 @@ def _linear_presolve(self, comp_by_linear_var, lcon_by_linear_nnz, var_bounds):
                 b = expr_info.const = (lb - expr_info.const) / coef
                 logger.debug("NL presolve: substituting %s := %s", var_map[_id], b)
                 eliminated_vars[_id] = expr_info
+                nl_map[_id] = template.const % b
                 lb, ub = var_bounds[_id]
                 if (lb is not None and lb - b > TOL) or (
                     ub is not None and ub - b < -TOL
@@ -1750,7 +1823,7 @@ def _linear_presolve(self, comp_by_linear_var, lcon_by_linear_nnz, var_bounds):
                 id2_isdiscrete = var_map[id2].domain.isdiscrete()
                 if var_map[_id].domain.isdiscrete() ^ id2_isdiscrete:
                     # if only one variable is discrete, then we need to
-                    # substiitute out the other
+                    # substitute out the other
                     if id2_isdiscrete:
                         _id, id2 = id2, _id
                         coef, coef2 = coef2, coef
@@ -1765,7 +1838,7 @@ def _linear_presolve(self, comp_by_linear_var, lcon_by_linear_nnz, var_bounds):
                     ):
                         _id, id2 = id2, _id
                         coef, coef2 = coef2, coef
-                # substituting _id with a*x + b
+                # eliminating _id and replacing it with a*x + b
                 a = -coef2 / coef
                 x = id2
                 b = expr_info.const = (lb - expr_info.const) / coef
@@ -1795,9 +1868,28 @@ def _linear_presolve(self, comp_by_linear_var, lcon_by_linear_nnz, var_bounds):
                 var_bounds[x] = x_lb, x_ub
                 if x_lb == x_ub and x_lb is not None:
                     fixed_vars.append(x)
+                # Given that we are eliminating a variable, we want to
+                # attempt to sanely resolve the initial variable values.
+                y_init = var_values[_id]
+                if y_init is not None:
+                    # Y has a value
+                    x_init = var_values[x]
+                    if x_init is None:
+                        # X does not; just use the one calculated from Y
+                        x_init = (y_init - b) / a
+                    else:
+                        # X does too, use the average of the two values
+                        x_init = (x_init + (y_init - b) / a) / 2.0
+                    # Ensure that the initial value respects the
+                    # tightened bounds
+                    if x_ub is not None and x_init > x_ub:
+                        x_init = x_ub
+                    if x_lb is not None and x_init < x_lb:
+                        x_init = x_lb
+                    var_values[x] = x_init
                 eliminated_cons.add(con_id)
             else:
-                return eliminated_cons, eliminated_vars
+                break
             for con_id, expr_info in comp_by_linear_var[_id]:
                 # Note that if we were aggregating (i.e., _id was
                 # from two_var), then one of these info's will be
@@ -1810,10 +1902,15 @@ def _linear_presolve(self, comp_by_linear_var, lcon_by_linear_nnz, var_bounds):
                 # appropriately (that expr_info is persisting in the
                 # eliminated_vars dict - and we will use that to
                 # update other linear expressions later.)
+                old_nnz = len(expr_info.linear)
                 c = expr_info.linear.pop(_id, 0)
+                nnz = old_nnz - 1
                 expr_info.const += c * b
                 if x in expr_info.linear:
                     expr_info.linear[x] += c * a
+                    if expr_info.linear[x] == 0:
+                        nnz -= 1
+                        coef = expr_info.linear.pop(x)
                 elif a:
                     expr_info.linear[x] = c * a
                     # replacing _id with x... NNZ is not changing,
@@ -1821,10 +1918,17 @@ def _linear_presolve(self, comp_by_linear_var, lcon_by_linear_nnz, var_bounds):
                     # this constraint
                     comp_by_linear_var[x].append((con_id, expr_info))
                     continue
-                # NNZ has been reduced by 1
-                nnz = len(expr_info.linear)
-                _old = lcon_by_linear_nnz[nnz + 1]
+                _old = lcon_by_linear_nnz[old_nnz]
                 if con_id in _old:
+                    if not nnz:
+                        if abs(expr_info.const) > TOL:
+                            # constraint is trivially infeasible
+                            raise InfeasibleConstraintException(
+                                "model contains a trivially infeasible constraint "
+                                f"{expr_info.const} == {coef}*{var_map[x]}"
+                            )
+                        # constraint is trivially feasible
+                        eliminated_cons.add(con_id)
                     lcon_by_linear_nnz[nnz][con_id] = _old.pop(con_id)
             # If variables were replaced by the variable that
             # we are currently eliminating, then we need to update
@@ -1837,6 +1941,42 @@ def _linear_presolve(self, comp_by_linear_var, lcon_by_linear_nnz, var_bounds):
                     expr_info.linear[x] += c * a
                 elif a:
                     expr_info.linear[x] = c * a
+                elif not expr_info.linear:
+                    nl_map[resubst] = template.const % expr_info.const
+
+        # Note: the ASL will (silently) produce incorrect answers if the
+        # nonlinear portion of a defined variable is a constant
+        # expression.  This may not be the case if all the variables in
+        # the original nonlinear expression have been fixed.
+        for _id, (expr, info, sub) in self.subexpression_cache.items():
+            if info.nonlinear:
+                nl, args = info.nonlinear
+                # Note: 'not args' skips string arguments
+                # Note: 'vid in nl_map' skips eliminated
+                #   variables and defined variables reduced to constants
+                if not args or any(vid not in nl_map for vid in args):
+                    continue
+                # Ideally, we would just evaluate the named expression.
+                # However, there might be a linear portion of the named
+                # expression that still has free variables, and there is no
+                # guarantee that the user actually initialized the
+                # variables.  So, we will fall back on parsing the (now
+                # constant) nonlinear fragment and evaluating it.
+                info.nonlinear = None
+                info.const += _evaluate_constant_nl(
+                    nl % tuple(nl_map[i] for i in args), self.external_functions
+                )
+            if not info.linear:
+                # This has resolved to a constant: the ASL will fail for
+                # defined variables containing ONLY a constant.  We
+                # need to substitute the constant directly into the
+                # original constraint/objective expression(s)
+                info.linear = {}
+                self.used_named_expressions.discard(_id)
+                nl_map[_id] = template.const % info.const
+                self.subexpression_cache[_id] = (expr, info, [None, None, True])
+
+        return eliminated_cons, eliminated_vars
 
     def _record_named_expression_usage(self, named_exprs, src, comp_type):
         self.used_named_expressions.update(named_exprs)
@@ -1848,6 +1988,18 @@ def _record_named_expression_usage(self, named_exprs, src, comp_type):
             elif info[comp_type] != src:
                 info[comp_type] = 0
 
+    def _resolve_subexpression_args(self, nl, args):
+        final_args = []
+        for arg in args:
+            if arg in self.var_id_to_nl_map:
+                final_args.append(self.var_id_to_nl_map[arg])
+            else:
+                _nl, _ids, _ = self.subexpression_cache[arg][1].compile_repn(
+                    self.visitor
+                )
+                final_args.append(self._resolve_subexpression_args(_nl, _ids))
+        return nl % tuple(final_args)
+
     def _write_nl_expression(self, repn, include_const):
         # Note that repn.mult should always be 1 (the AMPLRepn was
         # compiled before this point).  Omitting the assertion for
@@ -1862,7 +2014,13 @@ def _write_nl_expression(self, repn, include_const):
                 # Add the constant to the NL expression.  AMPL adds the
                 # constant as the second argument, so we will too.
                 nl = self.template.binary_sum + nl + self.template.const % repn.const
-            self.ostream.write(nl % tuple(map(self.var_id_to_nl.__getitem__, args)))
+            try:
+                self.ostream.write(
+                    nl % tuple(map(self.var_id_to_nl_map.__getitem__, args))
+                )
+            except KeyError:
+                self.ostream.write(self._resolve_subexpression_args(nl, args))
+
         elif include_const:
             self.ostream.write(self.template.const % repn.const)
         else:
@@ -1876,7 +2034,7 @@ def _write_v_line(self, expr_id, k):
             lbl = '\t#%s' % info[0].name
         else:
             lbl = ''
-        self.var_id_to_nl[expr_id] = f"v{self.next_V_line_id}{lbl}"
+        self.var_id_to_nl_map[expr_id] = f"v{self.next_V_line_id}{lbl}\n"
         # Do NOT write out 0 coefficients here: doing so fouls up the
         # ASL's logic for calculating derivatives, leading to 'nan' in
         # the Hessian results.
@@ -1884,7 +2042,7 @@ def _write_v_line(self, expr_id, k):
         #
         ostream.write(f'V{self.next_V_line_id} {len(linear)} {k}{lbl}\n')
         for _id in sorted(linear, key=column_order.__getitem__):
-            ostream.write(f'{column_order[_id]} {linear[_id]!r}\n')
+            ostream.write(f'{column_order[_id]} {linear[_id]!s}\n')
         self._write_nl_expression(info[1], True)
         self.next_V_line_id += 1
 
@@ -1959,7 +2117,7 @@ def duplicate(self):
         ans.const = self.const
         ans.linear = None if self.linear is None else dict(self.linear)
         ans.nonlinear = self.nonlinear
-        ans.named_exprs = self.named_exprs
+        ans.named_exprs = None if self.named_exprs is None else set(self.named_exprs)
         return ans
 
     def compile_repn(self, visitor, prefix='', args=None, named_exprs=None):
@@ -2204,7 +2362,9 @@ class text_nl_debug_template(object):
     less_equal = 'o23\t# le\n'
     equality = 'o24\t# eq\n'
     external_fcn = 'f%d %d%s\n'
-    var = '%s\n'  # NOTE: to support scaling, we do NOT include the 'v' here
+    # NOTE: to support scaling and substitutions, we do NOT include the
+    # 'v' or the EOL here:
+    var = '%s'
     const = 'n%r\n'
     string = 'h%d:%s\n'
     monomial = product + const + var.replace('%', '%%')
@@ -2213,8 +2373,45 @@ class text_nl_debug_template(object):
     _create_strict_inequality_map(vars())
 
 
+nl_operators = {
+    0: (2, operator.add),
+    2: (2, operator.mul),
+    3: (2, operator.truediv),
+    5: (2, operator.pow),
+    15: (1, operator.abs),
+    16: (1, operator.neg),
+    54: (None, lambda *x: sum(x)),
+    35: (3, lambda a, b, c: b if a else c),
+    21: (2, operator.and_),
+    22: (2, operator.lt),
+    23: (2, operator.le),
+    24: (2, operator.eq),
+    43: (1, math.log),
+    42: (1, math.log10),
+    41: (1, math.sin),
+    46: (1, math.cos),
+    38: (1, math.tan),
+    40: (1, math.sinh),
+    45: (1, math.cosh),
+    37: (1, math.tanh),
+    51: (1, math.asin),
+    53: (1, math.acos),
+    49: (1, math.atan),
+    44: (1, math.exp),
+    39: (1, math.sqrt),
+    50: (1, math.asinh),
+    52: (1, math.acosh),
+    47: (1, math.atanh),
+    14: (1, math.ceil),
+    13: (1, math.floor),
+}
+
+
 def _strip_template_comments(vars_, base_):
-    vars_['unary'] = {k: v[: v.find('\t#')] + '\n' for k, v in base_.unary.items()}
+    vars_['unary'] = {
+        k: v[: v.find('\t#')] + '\n' if v[-1] == '\n' else ''
+        for k, v in base_.unary.items()
+    }
     for k, v in base_.__dict__.items():
         if type(v) is str and '\t#' in v:
             v_lines = v.split('\n')
@@ -2465,6 +2662,15 @@ def handle_named_expression_node(visitor, node, arg1):
         expression_source,
     )
 
+    # As we will eventually need the compiled form of any nonlinear
+    # expression, we will go ahead and compile it here.  We do not
+    # do the same for the linear component as we will only need the
+    # linear component compiled to a dict if we are emitting the
+    # original (linear + nonlinear) V line (which will not happen if
+    # the V line is part of a larger linear operator).
+    if repn.nonlinear.__class__ is list:
+        repn.compile_nonlinear_fragment(visitor)
+
     if not visitor.use_named_exprs:
         return _GENERAL, repn.duplicate()
 
@@ -2477,15 +2683,6 @@ def handle_named_expression_node(visitor, node, arg1):
     repn.nl = (visitor.template.var, (_id,))
 
     if repn.nonlinear:
-        # As we will eventually need the compiled form of any nonlinear
-        # expression, we will go ahead and compile it here.  We do not
-        # do the same for the linear component as we will only need the
-        # linear component compiled to a dict if we are emitting the
-        # original (linear + nonlinear) V line (which will not happen if
-        # the V line is part of a larger linear operator).
-        if repn.nonlinear.__class__ is list:
-            repn.compile_nonlinear_fragment(visitor)
-
         if repn.linear:
             # If this expression has both linear and nonlinear
             # components, we will follow the ASL convention and break
@@ -2508,8 +2705,10 @@ def handle_named_expression_node(visitor, node, arg1):
             nl_info = list(expression_source)
             visitor.subexpression_cache[sub_id] = (sub_node, sub_repn, nl_info)
             # It is important that the NL subexpression comes before the
-            # main named expression:
-            visitor.subexpression_order.append(sub_id)
+            # main named expression: re-insert the original named
+            # expression (so that the nonlinear sub_node comes first
+            # when iterating over subexpression_cache)
+            visitor.subexpression_cache[_id] = visitor.subexpression_cache.pop(_id)
         else:
             nl_info = expression_source
     else:
@@ -2548,15 +2747,11 @@ def handle_named_expression_node(visitor, node, arg1):
 
     if expression_source[2]:
         if repn.linear:
-            return (_MONOMIAL, next(iter(repn.linear)), 1)
+            assert len(repn.linear) == 1 and not repn.const
+            return (_MONOMIAL,) + next(iter(repn.linear.items()))
         else:
             return (_CONSTANT, repn.const)
 
-    # Defer recording this _id until after we know that this repn will
-    # not be directly substituted (and to ensure that the NL fragment is
-    # added to the order first).
-    visitor.subexpression_order.append(_id)
-
     return (_GENERAL, repn.duplicate())
 
 
@@ -2564,9 +2759,12 @@ def handle_external_function_node(visitor, node, *args):
     func = node._fcn._function
     # There is a special case for external functions: these are the only
     # expressions that can accept string arguments. As we currently pass
-    # these as 'precompiled' general NL fragments, the normal trap for
-    # constant subexpressions will miss constant external function calls
-    # that contain strings.  We will catch that case here.
+    # these as 'precompiled' GENERAL AMPLRepns, the normal trap for
+    # constant subexpressions will miss string arguments.  We will catch
+    # that case here by looking for NL fragments with no variable
+    # references.  Note that the NL fragment is NOT the raw string
+    # argument that we want to evaluate: the raw string is in the
+    # `const` field.
     if all(
         arg[0] is _CONSTANT or (arg[0] is _GENERAL and arg[1].nl and not arg[1].nl[1])
         for arg in args
@@ -2582,8 +2780,8 @@ def handle_external_function_node(visitor, node, *args):
                 "correctly."
                 % (
                     func,
-                    visitor.external_byFcn[func]._library,
-                    visitor.external_byFcn[func]._library.name,
+                    visitor.external_functions[func]._library,
+                    visitor.external_functions[func]._library.name,
                     node._fcn._library,
                     node._fcn.name,
                 )
@@ -2591,14 +2789,33 @@ def handle_external_function_node(visitor, node, *args):
     else:
         visitor.external_functions[func] = (len(visitor.external_functions), node._fcn)
     comment = f'\t#{node.local_name}' if visitor.symbolic_solver_labels else ''
-    nonlin = node_result_to_amplrepn(args[0]).compile_repn(
-        visitor,
-        visitor.template.external_fcn
-        % (visitor.external_functions[func][0], len(args), comment),
+    nl = visitor.template.external_fcn % (
+        visitor.external_functions[func][0],
+        len(args),
+        comment,
+    )
+    arg_ids = []
+    named_exprs = set()
+    for arg in args:
+        _id = id(arg)
+        arg_ids.append(_id)
+        visitor.subexpression_cache[_id] = (
+            arg,
+            AMPLRepn(
+                0,
+                None,
+                node_result_to_amplrepn(arg).compile_repn(
+                    visitor, named_exprs=named_exprs
+                ),
+            ),
+            (None, None, True),
+        )
+    if not named_exprs:
+        named_exprs = None
+    return (
+        _GENERAL,
+        AMPLRepn(0, None, (nl + '%s' * len(arg_ids), arg_ids, named_exprs)),
     )
-    for arg in args[1:]:
-        nonlin = node_result_to_amplrepn(arg).compile_repn(visitor, *nonlin)
-    return (_GENERAL, AMPLRepn(0, None, nonlin))
 
 
 _operator_handles = ExitNodeDispatcher(
@@ -2758,6 +2975,20 @@ def _before_linear(visitor, child):
                     linear[_id] = arg1
             elif arg.__class__ in native_types:
                 const += arg
+            elif arg.is_variable_type():
+                _id = id(arg)
+                if _id not in var_map:
+                    if arg.fixed:
+                        if _id not in visitor.fixed_vars:
+                            visitor.cache_fixed_var(_id, arg)
+                        const += visitor.fixed_vars[_id]
+                        continue
+                    _before_child_handlers._record_var(visitor, arg)
+                    linear[_id] = 1
+                elif _id in linear:
+                    linear[_id] += 1
+                else:
+                    linear[_id] = 1
             else:
                 try:
                     const += visitor.check_constant(visitor.evaluate(arg), arg)
@@ -2792,7 +3023,6 @@ def __init__(
         self,
         template,
         subexpression_cache,
-        subexpression_order,
         external_functions,
         var_map,
         used_named_expressions,
@@ -2803,7 +3033,6 @@ def __init__(
         super().__init__()
         self.template = template
         self.subexpression_cache = subexpression_cache
-        self.subexpression_order = subexpression_order
         self.external_functions = external_functions
         self.active_expression_source = None
         self.var_map = var_map
@@ -2952,3 +3181,60 @@ def finalizeResult(self, result):
         #
         self.active_expression_source = None
         return ans
+
+
+def _evaluate_constant_nl(nl, external_functions):
+    expr = nl.splitlines()
+    stack = []
+    while expr:
+        line = expr.pop()
+        tokens = line.split()
+        # remove tokens after the first comment
+        for i, t in enumerate(tokens):
+            if t.startswith('#'):
+                tokens = tokens[:i]
+                break
+        if len(tokens) != 1:
+            # skip blank lines
+            if not tokens:
+                continue
+            if tokens[0][0] == 'f':
+                # external function
+                fid, nargs = tokens
+                fid = int(fid[1:])
+                nargs = int(nargs)
+                fcn_id, ef = external_functions[fid]
+                assert fid == fcn_id
+                stack.append(ef.evaluate(tuple(stack.pop() for i in range(nargs))))
+                continue
+            raise DeveloperError(
+                f"Unsupported line format _evaluate_constant_nl() "
+                f"(we expect each line to contain a single token): '{line}'"
+            )
+        term = tokens[0]
+        # the "command" can be determined by the first character on the line
+        cmd = term[0]
+        # Note that we will unpack the line into the expected number of
+        # explicit arguments as a form of error checking
+        if cmd == 'n':
+            # numeric constant
+            stack.append(float(term[1:]))
+        elif cmd == 'o':
+            # operator
+            nargs, fcn = nl_operators[int(term[1:])]
+            if nargs is None:
+                nargs = int(stack.pop())
+            stack.append(fcn(*(stack.pop() for i in range(nargs))))
+        elif cmd in '1234567890':
+            # this is either a single int (e.g., the nargs in a nary
+            # sum) or a string argument.  Preserve it as-is until later
+            # when we know which we are expecting.
+            stack.append(term)
+        elif cmd == 'h':
+            stack.append(term.split(':', 1)[1])
+        else:
+            raise DeveloperError(
+                f"Unsupported NL operator in _evaluate_constant_nl(): '{line}'"
+            )
+    assert len(stack) == 1
+    return stack[0]
diff --git a/pyomo/repn/plugins/standard_form.py b/pyomo/repn/plugins/standard_form.py
index c72661daaf0..e684829e2f4 100644
--- a/pyomo/repn/plugins/standard_form.py
+++ b/pyomo/repn/plugins/standard_form.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -20,6 +20,7 @@
     document_kwargs_from_configdict,
 )
 from pyomo.common.dependencies import scipy, numpy as np
+from pyomo.common.enums import ObjectiveSense
 from pyomo.common.gc_manager import PauseGC
 from pyomo.common.timing import TicTocTimer
 
@@ -61,12 +62,16 @@ class LinearStandardFormInfo(object):
 
     Attributes
     ----------
-    c : scipy.sparse.csr_array
+    c : scipy.sparse.csc_array
 
         The objective coefficients.  Note that this is a sparse array
         and may contain multiple rows (for multiobjective problems).  The
         objectives may be calculated by "c @ x"
 
+    c_offset : numpy.ndarray
+
+        The list of objective constant offsets
+
     A : scipy.sparse.csc_array
 
         The constraint coefficients.  The constraint bodies may be
@@ -76,37 +81,43 @@ class LinearStandardFormInfo(object):
 
         The constraint right-hand sides.
 
-    rows : List[Tuple[_ConstraintData, int]]
+    rows : List[Tuple[ConstraintData, int]]
 
         The list of Pyomo constraint objects corresponding to the rows
         in `A`.  Each element in the list is a 2-tuple of
-        (_ConstraintData, row_multiplier).  The `row_multiplier` will be
+        (ConstraintData, row_multiplier).  The `row_multiplier` will be
         +/- 1 indicating if the row was multiplied by -1 (corresponding
         to a constraint lower bound) or +1 (upper bound).
 
-    columns : List[_VarData]
+    columns : List[VarData]
 
         The list of Pyomo variable objects corresponding to columns in
         the `A` and `c` matrices.
 
-    eliminated_vars: List[Tuple[_VarData, NumericExpression]]
+    objectives : List[ObjectiveData]
+
+        The list of Pyomo objective objects corresponding to the active objectives
+
+    eliminated_vars: List[Tuple[VarData, NumericExpression]]
 
         The list of variables from the original model that do not appear
         in the standard form (usually because they were replaced by
         nonnegative variables).  Each entry is a 2-tuple of
-        (:py:class:`_VarData`, :py:class`NumericExpression`|`float`).
+        (:py:class:`VarData`, :py:class`NumericExpression`|`float`).
         The list is in the necessary order for correct evaluation (i.e.,
         all variables appearing in the expression must either have
         appeared in the standard form, or appear *earlier* in this list.
 
     """
 
-    def __init__(self, c, A, rhs, rows, columns, eliminated_vars):
+    def __init__(self, c, c_offset, A, rhs, rows, columns, objectives, eliminated_vars):
         self.c = c
+        self.c_offset = c_offset
         self.A = A
         self.rhs = rhs
         self.rows = rows
         self.columns = columns
+        self.objectives = objectives
         self.eliminated_vars = eliminated_vars
 
     @property
@@ -139,6 +150,23 @@ class LinearStandardFormCompiler(object):
             description='Add slack variables and return `min cTx s.t. Ax == b`',
         ),
     )
+    CONFIG.declare(
+        'mixed_form',
+        ConfigValue(
+            default=False,
+            domain=bool,
+            description='Return A in mixed form (the comparison operator is a '
+            'mix of <=, ==, and >=)',
+        ),
+    )
+    CONFIG.declare(
+        'set_sense',
+        ConfigValue(
+            default=ObjectiveSense.minimize,
+            domain=InEnum(ObjectiveSense),
+            description='If not None, map all objectives to the specified sense.',
+        ),
+    )
     CONFIG.declare(
         'show_section_timing',
         ConfigValue(
@@ -296,21 +324,19 @@ def write(self, model):
         #
         # Process objective
         #
-        if not component_map[Objective]:
-            objectives = [Objective(expr=1)]
-            objectives[0].construct()
-        else:
-            objectives = []
-            for blk in component_map[Objective]:
-                objectives.extend(
-                    blk.component_data_objects(
-                        Objective, active=True, descend_into=False, sort=sorter
-                    )
+        set_sense = self.config.set_sense
+        objectives = []
+        for blk in component_map[Objective]:
+            objectives.extend(
+                blk.component_data_objects(
+                    Objective, active=True, descend_into=False, sort=sorter
                 )
+            )
+        obj_offset = []
         obj_data = []
         obj_index = []
         obj_index_ptr = [0]
-        for i, obj in enumerate(objectives):
+        for obj in objectives:
             repn = visitor.walk_expression(obj.expr)
             if repn.nonlinear is not None:
                 raise ValueError(
@@ -319,8 +345,10 @@ def write(self, model):
                 )
             N = len(repn.linear)
             obj_data.append(np.fromiter(repn.linear.values(), float, N))
-            if obj.sense == maximize:
+            obj_offset.append(repn.constant)
+            if set_sense is not None and set_sense != obj.sense:
                 obj_data[-1] *= -1
+                obj_offset[-1] *= -1
             obj_index.append(
                 np.fromiter(map(var_order.__getitem__, repn.linear), float, N)
             )
@@ -332,6 +360,9 @@ def write(self, model):
         # Tabulate constraints
         #
         slack_form = self.config.slack_form
+        mixed_form = self.config.mixed_form
+        if slack_form and mixed_form:
+            raise ValueError("cannot specify both slack_form and mixed_form")
         rows = []
         rhs = []
         con_data = []
@@ -372,7 +403,30 @@ def write(self, model):
                     f"model contains a trivially infeasible constraint, '{con.name}'"
                 )
 
-            if slack_form:
+            if mixed_form:
+                N = len(repn.linear)
+                _data = np.fromiter(repn.linear.values(), float, N)
+                _index = np.fromiter(map(var_order.__getitem__, repn.linear), float, N)
+                if ub == lb:
+                    rows.append(RowEntry(con, 0))
+                    rhs.append(ub - offset)
+                    con_data.append(_data)
+                    con_index.append(_index)
+                    con_index_ptr.append(con_index_ptr[-1] + N)
+                else:
+                    if ub is not None:
+                        rows.append(RowEntry(con, 1))
+                        rhs.append(ub - offset)
+                        con_data.append(_data)
+                        con_index.append(_index)
+                        con_index_ptr.append(con_index_ptr[-1] + N)
+                    if lb is not None:
+                        rows.append(RowEntry(con, -1))
+                        rhs.append(lb - offset)
+                        con_data.append(_data)
+                        con_index.append(_index)
+                        con_index_ptr.append(con_index_ptr[-1] + N)
+            elif slack_form:
                 _data = list(repn.linear.values())
                 _index = list(map(var_order.__getitem__, repn.linear))
                 if lb == ub:  # TODO: add tolerance?
@@ -421,13 +475,17 @@ def write(self, model):
         # Get the variable list
         columns = list(var_map.values())
         # Convert the compiled data to scipy sparse matrices
+        if obj_data:
+            obj_data = np.concatenate(obj_data)
+            obj_index = np.concatenate(obj_index)
         c = scipy.sparse.csr_array(
-            (np.concatenate(obj_data), np.concatenate(obj_index), obj_index_ptr),
-            [len(obj_index_ptr) - 1, len(columns)],
+            (obj_data, obj_index, obj_index_ptr), [len(obj_index_ptr) - 1, len(columns)]
         ).tocsc()
+        if rows:
+            con_data = np.concatenate(con_data)
+            con_index = np.concatenate(con_index)
         A = scipy.sparse.csr_array(
-            (np.concatenate(con_data), np.concatenate(con_index), con_index_ptr),
-            [len(rows), len(columns)],
+            (con_data, con_index, con_index_ptr), [len(rows), len(columns)]
         ).tocsc()
 
         # Some variables in the var_map may not actually appear in the
@@ -437,24 +495,22 @@ def write(self, model):
         # at the index pointer list (an O(num_var) operation).
         c_ip = c.indptr
         A_ip = A.indptr
-        active_var_idx = list(
-            filter(
-                lambda i: A_ip[i] != A_ip[i + 1] or c_ip[i] != c_ip[i + 1],
-                range(len(columns)),
-            )
-        )
-        nCol = len(active_var_idx)
+        active_var_mask = (A_ip[1:] > A_ip[:-1]) | (c_ip[1:] > c_ip[:-1])
+
+        # Masks on NumPy arrays are very fast.  Build the reduced A
+        # indptr and then check if we actually have to manipulate the
+        # columns
+        augmented_mask = np.concatenate((active_var_mask, [True]))
+        reduced_A_indptr = A.indptr[augmented_mask]
+        nCol = len(reduced_A_indptr) - 1
         if nCol != len(columns):
-            # Note that the indptr can't just use range() because a var
-            # may only appear in the objectives or the constraints.
-            columns = list(map(columns.__getitem__, active_var_idx))
-            active_var_idx.append(c.indptr[-1])
+            columns = [v for k, v in zip(active_var_mask, columns) if k]
             c = scipy.sparse.csc_array(
-                (c.data, c.indices, c.indptr.take(active_var_idx)), [c.shape[0], nCol]
+                (c.data, c.indices, c.indptr[augmented_mask]), [c.shape[0], nCol]
             )
-            active_var_idx[-1] = A.indptr[-1]
+            # active_var_idx[-1] = len(columns)
             A = scipy.sparse.csc_array(
-                (A.data, A.indices, A.indptr.take(active_var_idx)), [A.shape[0], nCol]
+                (A.data, A.indices, reduced_A_indptr), [A.shape[0], nCol]
             )
 
         if self.config.nonnegative_vars:
@@ -462,7 +518,9 @@ def write(self, model):
         else:
             eliminated_vars = []
 
-        info = LinearStandardFormInfo(c, A, rhs, rows, columns, eliminated_vars)
+        info = LinearStandardFormInfo(
+            c, np.array(obj_offset), A, rhs, rows, columns, objectives, eliminated_vars
+        )
         timer.toc("Generated linear standard form representation", delta=False)
         return info
 
diff --git a/pyomo/repn/quadratic.py b/pyomo/repn/quadratic.py
index 2d11261de5d..a9c8b7bf2b5 100644
--- a/pyomo/repn/quadratic.py
+++ b/pyomo/repn/quadratic.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -98,22 +98,15 @@ def to_expression(self, visitor):
                         e += coef * (var_map[x1] * var_map[x2])
             ans += e
         if self.linear:
-            if len(self.linear) == 1:
-                vid, coef = next(iter(self.linear.items()))
-                if coef == 1:
-                    ans += var_map[vid]
-                elif coef:
-                    ans += MonomialTermExpression((coef, var_map[vid]))
-                else:
-                    pass
-            else:
-                ans += LinearExpression(
-                    [
-                        MonomialTermExpression((coef, var_map[vid]))
-                        for vid, coef in self.linear.items()
-                        if coef
-                    ]
-                )
+            var_map = visitor.var_map
+            with mutable_expression() as e:
+                for vid, coef in self.linear.items():
+                    if coef:
+                        e += coef * var_map[vid]
+            if e.nargs() > 1:
+                ans += e
+            elif e.nargs() == 1:
+                ans += e.arg(0)
         if self.constant:
             ans += self.constant
         if self.multiplier != 1:
@@ -164,17 +157,6 @@ def append(self, other):
                 self.nonlinear += nl
 
 
-_exit_node_handlers = copy.deepcopy(linear._exit_node_handlers)
-
-#
-# NEGATION
-#
-_exit_node_handlers[NegationExpression][(_QUADRATIC,)] = linear._handle_negation_ANY
-
-
-#
-# PRODUCT
-#
 def _mul_linear_linear(varOrder, linear1, linear2):
     quadratic = {}
     for vid1, coef1 in linear1.items():
@@ -282,126 +264,73 @@ def _handle_product_nonlinear(visitor, node, arg1, arg2):
     return _GENERAL, ans
 
 
-_exit_node_handlers[ProductExpression].update(
-    {
-        (_CONSTANT, _QUADRATIC): linear._handle_product_constant_ANY,
-        (_LINEAR, _QUADRATIC): _handle_product_nonlinear,
-        (_QUADRATIC, _QUADRATIC): _handle_product_nonlinear,
-        (_GENERAL, _QUADRATIC): _handle_product_nonlinear,
-        (_QUADRATIC, _CONSTANT): linear._handle_product_ANY_constant,
-        (_QUADRATIC, _LINEAR): _handle_product_nonlinear,
-        (_QUADRATIC, _GENERAL): _handle_product_nonlinear,
-        # Replace handler from the linear walker
-        (_LINEAR, _LINEAR): _handle_product_linear_linear,
-        (_GENERAL, _GENERAL): _handle_product_nonlinear,
-        (_GENERAL, _LINEAR): _handle_product_nonlinear,
-        (_LINEAR, _GENERAL): _handle_product_nonlinear,
-    }
-)
-
-#
-# DIVISION
-#
-_exit_node_handlers[DivisionExpression].update(
-    {
-        (_CONSTANT, _QUADRATIC): linear._handle_division_nonlinear,
-        (_LINEAR, _QUADRATIC): linear._handle_division_nonlinear,
-        (_QUADRATIC, _QUADRATIC): linear._handle_division_nonlinear,
-        (_GENERAL, _QUADRATIC): linear._handle_division_nonlinear,
-        (_QUADRATIC, _CONSTANT): linear._handle_division_ANY_constant,
-        (_QUADRATIC, _LINEAR): linear._handle_division_nonlinear,
-        (_QUADRATIC, _GENERAL): linear._handle_division_nonlinear,
-    }
-)
-
-
-#
-# EXPONENTIATION
-#
-_exit_node_handlers[PowExpression].update(
-    {
-        (_CONSTANT, _QUADRATIC): linear._handle_pow_nonlinear,
-        (_LINEAR, _QUADRATIC): linear._handle_pow_nonlinear,
-        (_QUADRATIC, _QUADRATIC): linear._handle_pow_nonlinear,
-        (_GENERAL, _QUADRATIC): linear._handle_pow_nonlinear,
-        (_QUADRATIC, _CONSTANT): linear._handle_pow_ANY_constant,
-        (_QUADRATIC, _LINEAR): linear._handle_pow_nonlinear,
-        (_QUADRATIC, _GENERAL): linear._handle_pow_nonlinear,
-    }
-)
-
-#
-# ABS and UNARY handlers
-#
-_exit_node_handlers[AbsExpression][(_QUADRATIC,)] = linear._handle_unary_nonlinear
-_exit_node_handlers[UnaryFunctionExpression][
-    (_QUADRATIC,)
-] = linear._handle_unary_nonlinear
-
-#
-# NAMED EXPRESSION handlers
-#
-_exit_node_handlers[Expression][(_QUADRATIC,)] = linear._handle_named_ANY
-
-#
-# EXPR_IF handlers
-#
-# Note: it is easier to just recreate the entire data structure, rather
-# than update it
-_exit_node_handlers[Expr_ifExpression] = {
-    (i, j, k): linear._handle_expr_if_nonlinear
-    for i in (_LINEAR, _QUADRATIC, _GENERAL)
-    for j in (_CONSTANT, _LINEAR, _QUADRATIC, _GENERAL)
-    for k in (_CONSTANT, _LINEAR, _QUADRATIC, _GENERAL)
-}
-for j in (_CONSTANT, _LINEAR, _QUADRATIC, _GENERAL):
-    for k in (_CONSTANT, _LINEAR, _QUADRATIC, _GENERAL):
-        _exit_node_handlers[Expr_ifExpression][
-            _CONSTANT, j, k
-        ] = linear._handle_expr_if_const
-
-#
-# RELATIONAL handlers
-#
-_exit_node_handlers[EqualityExpression].update(
-    {
-        (_CONSTANT, _QUADRATIC): linear._handle_equality_general,
-        (_LINEAR, _QUADRATIC): linear._handle_equality_general,
-        (_QUADRATIC, _QUADRATIC): linear._handle_equality_general,
-        (_GENERAL, _QUADRATIC): linear._handle_equality_general,
-        (_QUADRATIC, _CONSTANT): linear._handle_equality_general,
-        (_QUADRATIC, _LINEAR): linear._handle_equality_general,
-        (_QUADRATIC, _GENERAL): linear._handle_equality_general,
-    }
-)
-_exit_node_handlers[InequalityExpression].update(
-    {
-        (_CONSTANT, _QUADRATIC): linear._handle_inequality_general,
-        (_LINEAR, _QUADRATIC): linear._handle_inequality_general,
-        (_QUADRATIC, _QUADRATIC): linear._handle_inequality_general,
-        (_GENERAL, _QUADRATIC): linear._handle_inequality_general,
-        (_QUADRATIC, _CONSTANT): linear._handle_inequality_general,
-        (_QUADRATIC, _LINEAR): linear._handle_inequality_general,
-        (_QUADRATIC, _GENERAL): linear._handle_inequality_general,
-    }
-)
-_exit_node_handlers[RangedExpression].update(
-    {
-        (_CONSTANT, _QUADRATIC): linear._handle_ranged_general,
-        (_LINEAR, _QUADRATIC): linear._handle_ranged_general,
-        (_QUADRATIC, _QUADRATIC): linear._handle_ranged_general,
-        (_GENERAL, _QUADRATIC): linear._handle_ranged_general,
-        (_QUADRATIC, _CONSTANT): linear._handle_ranged_general,
-        (_QUADRATIC, _LINEAR): linear._handle_ranged_general,
-        (_QUADRATIC, _GENERAL): linear._handle_ranged_general,
-    }
-)
+def define_exit_node_handlers(_exit_node_handlers=None):
+    if _exit_node_handlers is None:
+        _exit_node_handlers = {}
+    linear.define_exit_node_handlers(_exit_node_handlers)
+    #
+    # NEGATION
+    #
+    _exit_node_handlers[NegationExpression][(_QUADRATIC,)] = linear._handle_negation_ANY
+    #
+    # PRODUCT
+    #
+    _exit_node_handlers[ProductExpression].update(
+        {
+            None: _handle_product_nonlinear,
+            (_CONSTANT, _QUADRATIC): linear._handle_product_constant_ANY,
+            (_QUADRATIC, _CONSTANT): linear._handle_product_ANY_constant,
+            # Replace handler from the linear walker
+            (_LINEAR, _LINEAR): _handle_product_linear_linear,
+        }
+    )
+    #
+    # DIVISION
+    #
+    _exit_node_handlers[DivisionExpression].update(
+        {(_QUADRATIC, _CONSTANT): linear._handle_division_ANY_constant}
+    )
+    #
+    # EXPONENTIATION
+    #
+    _exit_node_handlers[PowExpression].update(
+        {(_QUADRATIC, _CONSTANT): linear._handle_pow_ANY_constant}
+    )
+    #
+    # ABS and UNARY handlers
+    #
+    # (no changes needed)
+    #
+    # NAMED EXPRESSION handlers
+    #
+    # (no changes needed)
+    #
+    # EXPR_IF handlers
+    #
+    # Note: it is easier to just recreate the entire data structure, rather
+    # than update it
+    _exit_node_handlers[Expr_ifExpression].update(
+        {
+            (_CONSTANT, i, _QUADRATIC): linear._handle_expr_if_const
+            for i in (_CONSTANT, _LINEAR, _QUADRATIC, _GENERAL)
+        }
+    )
+    _exit_node_handlers[Expr_ifExpression].update(
+        {
+            (_CONSTANT, _QUADRATIC, i): linear._handle_expr_if_const
+            for i in (_CONSTANT, _LINEAR, _GENERAL)
+        }
+    )
+    #
+    # RELATIONAL handlers
+    #
+    # (no changes needed)
+    return _exit_node_handlers
 
 
 class QuadraticRepnVisitor(linear.LinearRepnVisitor):
     Result = QuadraticRepn
-    exit_node_handlers = _exit_node_handlers
     exit_node_dispatcher = linear.ExitNodeDispatcher(
-        linear._initialize_exit_node_dispatcher(_exit_node_handlers)
+        linear._initialize_exit_node_dispatcher(define_exit_node_handlers())
     )
     max_exponential_expansion = 2
diff --git a/pyomo/repn/standard_aux.py b/pyomo/repn/standard_aux.py
index 8704253eca3..403320c462c 100644
--- a/pyomo/repn/standard_aux.py
+++ b/pyomo/repn/standard_aux.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -10,9 +10,6 @@
 #  ___________________________________________________________________________
 
 
-__all__ = ['compute_standard_repn']
-
-
 from pyomo.repn.standard_repn import (
     preprocess_block_constraints,
     preprocess_block_objectives,
diff --git a/pyomo/repn/standard_repn.py b/pyomo/repn/standard_repn.py
index 53618d3eb50..b767ab727af 100644
--- a/pyomo/repn/standard_repn.py
+++ b/pyomo/repn/standard_repn.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -10,9 +10,6 @@
 #  ___________________________________________________________________________
 
 
-__all__ = ['StandardRepn', 'generate_standard_repn']
-
-
 import sys
 import logging
 import itertools
@@ -22,11 +19,15 @@
 
 import pyomo.core.expr as EXPR
 from pyomo.core.expr.numvalue import NumericConstant
-from pyomo.core.base.objective import _GeneralObjectiveData, ScalarObjective
-from pyomo.core.base import _ExpressionData, Expression
-from pyomo.core.base.expression import ScalarExpression, _GeneralExpressionData
-from pyomo.core.base.var import ScalarVar, Var, _GeneralVarData, value
-from pyomo.core.base.param import ScalarParam, _ParamData
+from pyomo.core.base.objective import ObjectiveData, ScalarObjective
+from pyomo.core.base import Expression
+from pyomo.core.base.expression import (
+    ScalarExpression,
+    NamedExpressionData,
+    ExpressionData,
+)
+from pyomo.core.base.var import ScalarVar, Var, VarData, value
+from pyomo.core.base.param import ScalarParam, ParamData
 from pyomo.core.kernel.expression import expression, noclone
 from pyomo.core.kernel.variable import IVariable, variable
 from pyomo.core.kernel.objective import objective
@@ -324,6 +325,16 @@ def generate_standard_repn(
                             linear_vars[id_] = v
                     elif arg.__class__ in native_numeric_types:
                         C_ += arg
+                    elif arg.is_variable_type():
+                        if arg.fixed:
+                            C_ += arg.value
+                            continue
+                        id_ = id(arg)
+                        if id_ in linear_coefs:
+                            linear_coefs[id_] += 1
+                        else:
+                            linear_coefs[id_] = 1
+                            linear_vars[id_] = arg
                     else:
                         C_ += EXPR.evaluate_expression(arg)
             else:  # compute_values == False
@@ -339,6 +350,18 @@ def generate_standard_repn(
                         else:
                             linear_coefs[id_] = c
                             linear_vars[id_] = v
+                    elif arg.__class__ in native_numeric_types:
+                        C_ += arg
+                    elif arg.is_variable_type():
+                        if arg.fixed:
+                            C_ += arg
+                            continue
+                        id_ = id(arg)
+                        if id_ in linear_coefs:
+                            linear_coefs[id_] += 1
+                        else:
+                            linear_coefs[id_] = 1
+                            linear_vars[id_] = arg
                     else:
                         C_ += arg
 
@@ -1117,25 +1140,25 @@ def _collect_external_fn(exp, multiplier, idMap, compute_values, verbose, quadra
     EXPR.RangedExpression: _collect_comparison,
     EXPR.EqualityExpression: _collect_comparison,
     EXPR.ExternalFunctionExpression: _collect_external_fn,
-    # _ConnectorData          : _collect_linear_connector,
+    # ConnectorData          : _collect_linear_connector,
     # ScalarConnector         : _collect_linear_connector,
-    _ParamData: _collect_const,
+    ParamData: _collect_const,
     ScalarParam: _collect_const,
     # param.Param             : _collect_linear_const,
     # parameter               : _collect_linear_const,
     NumericConstant: _collect_const,
-    _GeneralVarData: _collect_var,
+    VarData: _collect_var,
     ScalarVar: _collect_var,
     Var: _collect_var,
     variable: _collect_var,
     IVariable: _collect_var,
-    _GeneralExpressionData: _collect_identity,
+    ExpressionData: _collect_identity,
     ScalarExpression: _collect_identity,
     expression: _collect_identity,
     noclone: _collect_identity,
-    _ExpressionData: _collect_identity,
+    NamedExpressionData: _collect_identity,
     Expression: _collect_identity,
-    _GeneralObjectiveData: _collect_identity,
+    ObjectiveData: _collect_identity,
     ScalarObjective: _collect_identity,
     objective: _collect_identity,
 }
@@ -1517,24 +1540,24 @@ def _linear_collect_pow(exp, multiplier, idMap, compute_values, verbose, coef):
     #EXPR.EqualityExpression                     : _linear_collect_comparison,
     #EXPR.ExternalFunctionExpression             : _linear_collect_external_fn,
     ##EXPR.LinearSumExpression               : _collect_linear_sum,
-    ##_ConnectorData          : _collect_linear_connector,
+    ##ConnectorData          : _collect_linear_connector,
     ##ScalarConnector         : _collect_linear_connector,
-    ##param._ParamData        : _collect_linear_const,
+    ##param.ParamData        : _collect_linear_const,
     ##param.ScalarParam       : _collect_linear_const,
     ##param.Param             : _collect_linear_const,
     ##parameter               : _collect_linear_const,
-    _GeneralVarData                             : _linear_collect_var,
+    VarData                             : _linear_collect_var,
     ScalarVar                                   : _linear_collect_var,
     Var                                         : _linear_collect_var,
     variable                                    : _linear_collect_var,
     IVariable                                   : _linear_collect_var,
-    _GeneralExpressionData                      : _linear_collect_identity,
+    ExpressionData                      : _linear_collect_identity,
     ScalarExpression                            : _linear_collect_identity,
     expression                                  : _linear_collect_identity,
     noclone                                     : _linear_collect_identity,
-    _ExpressionData                             : _linear_collect_identity,
+    NamedExpressionData                             : _linear_collect_identity,
     Expression                                  : _linear_collect_identity,
-    _GeneralObjectiveData                       : _linear_collect_identity,
+    ObjectiveData                       : _linear_collect_identity,
     ScalarObjective                             : _linear_collect_identity,
     objective                                   : _linear_collect_identity,
     }
diff --git a/pyomo/repn/tests/__init__.py b/pyomo/repn/tests/__init__.py
index 5e413c0132c..a9e1a5bea47 100644
--- a/pyomo/repn/tests/__init__.py
+++ b/pyomo/repn/tests/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/ampl/__init__.py b/pyomo/repn/tests/ampl/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/repn/tests/ampl/__init__.py
+++ b/pyomo/repn/tests/ampl/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/repn/tests/ampl/helper.py b/pyomo/repn/tests/ampl/helper.py
index eb09afc37cc..2bf2198d20f 100644
--- a/pyomo/repn/tests/ampl/helper.py
+++ b/pyomo/repn/tests/ampl/helper.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/ampl/nl_diff.py b/pyomo/repn/tests/ampl/nl_diff.py
index ecac3967dfe..9fe352ee503 100644
--- a/pyomo/repn/tests/ampl/nl_diff.py
+++ b/pyomo/repn/tests/ampl/nl_diff.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/ampl/small10_testCase.py b/pyomo/repn/tests/ampl/small10_testCase.py
index f51aea76d3e..deb56f92a88 100644
--- a/pyomo/repn/tests/ampl/small10_testCase.py
+++ b/pyomo/repn/tests/ampl/small10_testCase.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/ampl/small11_testCase.py b/pyomo/repn/tests/ampl/small11_testCase.py
index 5874007e13c..11b61805d5e 100644
--- a/pyomo/repn/tests/ampl/small11_testCase.py
+++ b/pyomo/repn/tests/ampl/small11_testCase.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/ampl/small12_testCase.py b/pyomo/repn/tests/ampl/small12_testCase.py
index 63d4ba29cf6..b73a8f528f2 100644
--- a/pyomo/repn/tests/ampl/small12_testCase.py
+++ b/pyomo/repn/tests/ampl/small12_testCase.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/ampl/small13_testCase.py b/pyomo/repn/tests/ampl/small13_testCase.py
index 9814c979cc7..c24185bf8d7 100644
--- a/pyomo/repn/tests/ampl/small13_testCase.py
+++ b/pyomo/repn/tests/ampl/small13_testCase.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/ampl/small14_testCase.py b/pyomo/repn/tests/ampl/small14_testCase.py
index 3d896242243..fb2c2bc6c5e 100644
--- a/pyomo/repn/tests/ampl/small14_testCase.py
+++ b/pyomo/repn/tests/ampl/small14_testCase.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/ampl/small15_testCase.py b/pyomo/repn/tests/ampl/small15_testCase.py
index 8345621cecd..d4d5796aaa5 100644
--- a/pyomo/repn/tests/ampl/small15_testCase.py
+++ b/pyomo/repn/tests/ampl/small15_testCase.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/ampl/small1_testCase.py b/pyomo/repn/tests/ampl/small1_testCase.py
index 00e6dd322ed..06f5ad122d9 100644
--- a/pyomo/repn/tests/ampl/small1_testCase.py
+++ b/pyomo/repn/tests/ampl/small1_testCase.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/ampl/small2_testCase.py b/pyomo/repn/tests/ampl/small2_testCase.py
index 2df3aebb139..8a65779f55e 100644
--- a/pyomo/repn/tests/ampl/small2_testCase.py
+++ b/pyomo/repn/tests/ampl/small2_testCase.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/ampl/small3_testCase.py b/pyomo/repn/tests/ampl/small3_testCase.py
index f11137979b4..999143d9a0c 100644
--- a/pyomo/repn/tests/ampl/small3_testCase.py
+++ b/pyomo/repn/tests/ampl/small3_testCase.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/ampl/small4_testCase.py b/pyomo/repn/tests/ampl/small4_testCase.py
index 08d68c21f50..9736dd9bf3b 100644
--- a/pyomo/repn/tests/ampl/small4_testCase.py
+++ b/pyomo/repn/tests/ampl/small4_testCase.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/ampl/small5_testCase.py b/pyomo/repn/tests/ampl/small5_testCase.py
index 1e976820f9b..1f254b7f04d 100644
--- a/pyomo/repn/tests/ampl/small5_testCase.py
+++ b/pyomo/repn/tests/ampl/small5_testCase.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/ampl/small6_testCase.py b/pyomo/repn/tests/ampl/small6_testCase.py
index da9f1d58f9b..9d309c09fef 100644
--- a/pyomo/repn/tests/ampl/small6_testCase.py
+++ b/pyomo/repn/tests/ampl/small6_testCase.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/ampl/small7_testCase.py b/pyomo/repn/tests/ampl/small7_testCase.py
index 22a75a33394..485962dd211 100644
--- a/pyomo/repn/tests/ampl/small7_testCase.py
+++ b/pyomo/repn/tests/ampl/small7_testCase.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/ampl/small8_testCase.py b/pyomo/repn/tests/ampl/small8_testCase.py
index 554e27c0924..61a3e3ccce7 100644
--- a/pyomo/repn/tests/ampl/small8_testCase.py
+++ b/pyomo/repn/tests/ampl/small8_testCase.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/ampl/small9_testCase.py b/pyomo/repn/tests/ampl/small9_testCase.py
index 3d7af602a88..7cb0913a762 100644
--- a/pyomo/repn/tests/ampl/small9_testCase.py
+++ b/pyomo/repn/tests/ampl/small9_testCase.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/ampl/test_ampl_comparison.py b/pyomo/repn/tests/ampl/test_ampl_comparison.py
index eb5aff329e1..8210bbdd173 100644
--- a/pyomo/repn/tests/ampl/test_ampl_comparison.py
+++ b/pyomo/repn/tests/ampl/test_ampl_comparison.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/ampl/test_ampl_nl.py b/pyomo/repn/tests/ampl/test_ampl_nl.py
index bd58c254bfd..53a2d3cda82 100644
--- a/pyomo/repn/tests/ampl/test_ampl_nl.py
+++ b/pyomo/repn/tests/ampl/test_ampl_nl.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/ampl/test_ampl_repn.py b/pyomo/repn/tests/ampl/test_ampl_repn.py
index cf1a889006e..9c911540eb0 100644
--- a/pyomo/repn/tests/ampl/test_ampl_repn.py
+++ b/pyomo/repn/tests/ampl/test_ampl_repn.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/ampl/test_nlv2.py b/pyomo/repn/tests/ampl/test_nlv2.py
index 6422a2b0020..4d7b5d9ab6c 100644
--- a/pyomo/repn/tests/ampl/test_nlv2.py
+++ b/pyomo/repn/tests/ampl/test_nlv2.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -25,6 +25,7 @@
 
 from pyomo.common.dependencies import numpy, numpy_available
 from pyomo.common.errors import MouseTrap
+from pyomo.common.gsl import find_GSL
 from pyomo.common.log import LoggingIntercept
 from pyomo.common.tee import capture_output
 from pyomo.common.tempfiles import TempfileManager
@@ -42,6 +43,8 @@
     Suffix,
     Constraint,
     Expression,
+    Binary,
+    Integers,
 )
 import pyomo.environ as pyo
 
@@ -55,7 +58,6 @@ def __init__(self, symbolic=False):
         else:
             self.template = nl_writer.text_nl_template
         self.subexpression_cache = {}
-        self.subexpression_order = []
         self.external_functions = {}
         self.var_map = {}
         self.used_named_expressions = set()
@@ -64,7 +66,6 @@ def __init__(self, symbolic=False):
         self.visitor = nl_writer.AMPLRepnVisitor(
             self.template,
             self.subexpression_cache,
-            self.subexpression_order,
             self.external_functions,
             self.var_map,
             self.used_named_expressions,
@@ -97,7 +98,7 @@ def test_divide(self):
         self.assertEqual(repn.mult, 1)
         self.assertEqual(repn.const, 0)
         self.assertEqual(repn.linear, {})
-        self.assertEqual(repn.nonlinear, ('o5\n%s\nn2\n', [id(m.x)]))
+        self.assertEqual(repn.nonlinear, ('o5\n%sn2\n', [id(m.x)]))
 
         m.p = 2
 
@@ -149,7 +150,7 @@ def test_divide(self):
         self.assertEqual(repn.mult, 1)
         self.assertEqual(repn.const, 0)
         self.assertEqual(repn.linear, {})
-        self.assertEqual(repn.nonlinear, ('o2\nn0.5\no5\n%s\nn2\n', [id(m.x)]))
+        self.assertEqual(repn.nonlinear, ('o2\nn0.5\no5\n%sn2\n', [id(m.x)]))
 
         info = INFO()
         with LoggingIntercept() as LOG:
@@ -159,7 +160,7 @@ def test_divide(self):
         self.assertEqual(repn.mult, 1)
         self.assertEqual(repn.const, 0)
         self.assertEqual(repn.linear, {})
-        self.assertEqual(repn.nonlinear, ('o3\no43\n%s\n%s\n', [id(m.x), id(m.x)]))
+        self.assertEqual(repn.nonlinear, ('o3\no43\n%s%s', [id(m.x), id(m.x)]))
 
     def test_errors_divide_by_0(self):
         m = ConcreteModel()
@@ -254,7 +255,7 @@ def test_pow(self):
         self.assertEqual(repn.mult, 1)
         self.assertEqual(repn.const, 0)
         self.assertEqual(repn.linear, {})
-        self.assertEqual(repn.nonlinear, ('o5\n%s\nn2\n', [id(m.x)]))
+        self.assertEqual(repn.nonlinear, ('o5\n%sn2\n', [id(m.x)]))
 
         m.p = 1
         info = INFO()
@@ -541,7 +542,7 @@ def test_errors_propagate_nan(self):
         self.assertEqual(repn.mult, 1)
         self.assertEqual(repn.const, InvalidNumber(None))
         self.assertEqual(repn.linear, {})
-        self.assertEqual(repn.nonlinear[0], 'o16\no2\no2\n%s\n%s\n%s\n')
+        self.assertEqual(repn.nonlinear[0], 'o16\no2\no2\n%s%s%s')
         self.assertEqual(repn.nonlinear[1], [id(m.z[2]), id(m.z[3]), id(m.z[4])])
 
         m.z[3].fix(float('nan'))
@@ -591,7 +592,7 @@ def test_eval_pow(self):
         self.assertEqual(repn.mult, 1)
         self.assertEqual(repn.const, 0)
         self.assertEqual(repn.linear, {})
-        self.assertEqual(repn.nonlinear, ('o5\n%s\nn0.5\n', [id(m.x)]))
+        self.assertEqual(repn.nonlinear, ('o5\n%sn0.5\n', [id(m.x)]))
 
         m.x.fix()
         info = INFO()
@@ -616,7 +617,7 @@ def test_eval_abs(self):
         self.assertEqual(repn.mult, 1)
         self.assertEqual(repn.const, 0)
         self.assertEqual(repn.linear, {})
-        self.assertEqual(repn.nonlinear, ('o15\n%s\n', [id(m.x)]))
+        self.assertEqual(repn.nonlinear, ('o15\n%s', [id(m.x)]))
 
         m.x.fix()
         info = INFO()
@@ -641,7 +642,7 @@ def test_eval_unary_func(self):
         self.assertEqual(repn.mult, 1)
         self.assertEqual(repn.const, 0)
         self.assertEqual(repn.linear, {})
-        self.assertEqual(repn.nonlinear, ('o43\n%s\n', [id(m.x)]))
+        self.assertEqual(repn.nonlinear, ('o43\n%s', [id(m.x)]))
 
         m.x.fix()
         info = INFO()
@@ -670,7 +671,7 @@ def test_eval_expr_if_lessEq(self):
         self.assertEqual(repn.linear, {})
         self.assertEqual(
             repn.nonlinear,
-            ('o35\no23\n%s\nn4\no5\n%s\nn2\n%s\n', [id(m.x), id(m.x), id(m.y)]),
+            ('o35\no23\n%sn4\no5\n%sn2\n%s', [id(m.x), id(m.x), id(m.y)]),
         )
 
         m.x.fix()
@@ -711,7 +712,7 @@ def test_eval_expr_if_Eq(self):
         self.assertEqual(repn.linear, {})
         self.assertEqual(
             repn.nonlinear,
-            ('o35\no24\n%s\nn4\no5\n%s\nn2\n%s\n', [id(m.x), id(m.x), id(m.y)]),
+            ('o35\no24\n%sn4\no5\n%sn2\n%s', [id(m.x), id(m.x), id(m.y)]),
         )
 
         m.x.fix()
@@ -753,7 +754,7 @@ def test_eval_expr_if_ranged(self):
         self.assertEqual(
             repn.nonlinear,
             (
-                'o35\no21\no23\nn1\n%s\no23\n%s\nn4\no5\n%s\nn2\n%s\n',
+                'o35\no21\no23\nn1\n%so23\n%sn4\no5\n%sn2\n%s',
                 [id(m.x), id(m.x), id(m.x), id(m.y)],
             ),
         )
@@ -814,7 +815,7 @@ class CustomExpression(ScalarExpression):
         self.assertEqual(len(info.subexpression_cache), 1)
         obj, repn, info = info.subexpression_cache[id(m.e)]
         self.assertIs(obj, m.e)
-        self.assertEqual(repn.nl, ('%s\n', (id(m.e),)))
+        self.assertEqual(repn.nl, ('%s', (id(m.e),)))
         self.assertEqual(repn.mult, 1)
         self.assertEqual(repn.const, 3)
         self.assertEqual(repn.linear, {id(m.x): 1})
@@ -841,7 +842,7 @@ def test_nested_operator_zero_arg(self):
         self.assertEqual(repn.mult, 1)
         self.assertEqual(repn.const, 0)
         self.assertEqual(repn.linear, {})
-        self.assertEqual(repn.nonlinear, ('o24\no3\nn1\n%s\nn0\n', [id(m.x)]))
+        self.assertEqual(repn.nonlinear, ('o24\no3\nn1\n%sn0\n', [id(m.x)]))
 
     def test_duplicate_shared_linear_expressions(self):
         # This tests an issue where AMPLRepn.duplicate() was not copying
@@ -928,7 +929,7 @@ def test_AMPLRepn_to_expr(self):
         self.assertEqual(repn.mult, 1)
         self.assertEqual(repn.const, 0)
         self.assertEqual(repn.linear, {id(m.x[2]): 4, id(m.x[3]): 9, id(m.x[4]): 16})
-        self.assertEqual(repn.nonlinear, ('o5\n%s\nn2\n', [id(m.x[2])]))
+        self.assertEqual(repn.nonlinear, ('o5\n%sn2\n', [id(m.x[2])]))
         with self.assertRaisesRegex(
             MouseTrap, "Cannot convert nonlinear AMPLRepn to Pyomo Expression"
         ):
@@ -1096,7 +1097,6 @@ def test_log_timing(self):
         m.c1 = Constraint([1, 2], rule=lambda m, i: sum(m.x.values()) == 1)
         m.c2 = Constraint(expr=m.p * m.x[1] ** 2 + m.x[2] ** 3 <= 100)
 
-        self.maxDiff = None
         OUT = io.StringIO()
         with capture_output() as LOG:
             with report_timing(level=logging.DEBUG):
@@ -1267,7 +1267,7 @@ def test_nonfloat_constants(self):
  0 0   #network constraints: nonlinear, linear
  0 0 0 #nonlinear vars in constraints, objectives, both
  0 0 0 1       #linear network variables; functions; arith, flags
- 0 4 0 0 0     #discrete variables: binary, integer, nonlinear (b,c,o)
+ 4 0 0 0 0     #discrete variables: binary, integer, nonlinear (b,c,o)
  4 4   #nonzeros in Jacobian, obj. gradient
  6 4   #max name lengths: constraints, variables
  0 0 0 0 0     #common exprs: b,c,o,c1,o1
@@ -1688,6 +1688,257 @@ def test_presolve_named_expressions(self):
             )
         )
 
+    def test_presolve_zero_coef(self):
+        m = ConcreteModel()
+        m.x = Var()
+        m.y = Var()
+        m.z = Var()
+        m.obj = Objective(expr=m.x**2 + m.y**2 + m.z**2)
+        m.c1 = Constraint(expr=m.x == m.y + m.z + 1.5)
+        m.c2 = Constraint(expr=m.z == -m.y)
+
+        OUT = io.StringIO()
+        with LoggingIntercept() as LOG:
+            nlinfo = nl_writer.NLWriter().write(
+                m, OUT, symbolic_solver_labels=True, linear_presolve=True
+            )
+        self.assertEqual(LOG.getvalue(), "")
+
+        self.assertEqual(nlinfo.eliminated_vars[0], (m.x, 1.5))
+        self.assertIs(nlinfo.eliminated_vars[1][0], m.y)
+        self.assertExpressionsEqual(
+            nlinfo.eliminated_vars[1][1], LinearExpression([-1.0 * m.z])
+        )
+
+        self.assertEqual(
+            *nl_diff(
+                """g3 1 1 0	# problem unknown
+ 1 0 1 0 0	#vars, constraints, objectives, ranges, eqns
+ 0 1 0 0 0 0	#nonlinear constrs, objs; ccons: lin, nonlin, nd, nzlb
+ 0 0	#network constraints: nonlinear, linear
+ 0 1 0	#nonlinear vars in constraints, objectives, both
+ 0 0 0 1	#linear network variables; functions; arith, flags
+ 0 0 0 0 0	#discrete variables: binary, integer, nonlinear (b,c,o)
+ 0 1	#nonzeros in Jacobian, obj. gradient
+ 3 1	#max name lengths: constraints, variables
+ 0 0 0 0 0	#common exprs: b,c,o,c1,o1
+O0 0	#obj
+o54	#sumlist
+3	#(n)
+o5	#^
+n1.5
+n2
+o5	#^
+o16	#-
+v0	#z
+n2
+o5	#^
+v0	#z
+n2
+x0	#initial guess
+r	#0 ranges (rhs's)
+b	#1 bounds (on variables)
+3	#z
+k0	#intermediate Jacobian column lengths
+G0 1	#obj
+0 0
+""",
+                OUT.getvalue(),
+            )
+        )
+
+        m.c3 = Constraint(expr=m.x == 2)
+        OUT = io.StringIO()
+        with LoggingIntercept() as LOG:
+            with self.assertRaisesRegex(
+                nl_writer.InfeasibleConstraintException,
+                r"model contains a trivially infeasible constraint 0.5 == 0.0\*y",
+            ):
+                nlinfo = nl_writer.NLWriter().write(
+                    m, OUT, symbolic_solver_labels=True, linear_presolve=True
+                )
+        self.assertEqual(LOG.getvalue(), "")
+
+        m.c1.set_value(m.x >= m.y + m.z + 1.5)
+        OUT = io.StringIO()
+        with LoggingIntercept() as LOG:
+            nlinfo = nl_writer.NLWriter().write(
+                m,
+                OUT,
+                symbolic_solver_labels=True,
+                linear_presolve=True,
+                skip_trivial_constraints=False,
+            )
+        self.assertEqual(LOG.getvalue(), "")
+
+        self.assertIs(nlinfo.eliminated_vars[0][0], m.y)
+        self.assertExpressionsEqual(
+            nlinfo.eliminated_vars[0][1], LinearExpression([-1.0 * m.z])
+        )
+        self.assertEqual(nlinfo.eliminated_vars[1], (m.x, 2))
+
+        self.assertEqual(
+            *nl_diff(
+                """g3 1 1 0	# problem unknown
+ 1 1 1 0 0	#vars, constraints, objectives, ranges, eqns
+ 0 1 0 0 0 0	#nonlinear constrs, objs; ccons: lin, nonlin, nd, nzlb
+ 0 0	#network constraints: nonlinear, linear
+ 0 1 0	#nonlinear vars in constraints, objectives, both
+ 0 0 0 1	#linear network variables; functions; arith, flags
+ 0 0 0 0 0	#discrete variables: binary, integer, nonlinear (b,c,o)
+ 0 1	#nonzeros in Jacobian, obj. gradient
+ 3 1	#max name lengths: constraints, variables
+ 0 0 0 0 0	#common exprs: b,c,o,c1,o1
+C0	#c1
+n0
+O0 0	#obj
+o54	#sumlist
+3	#(n)
+o5	#^
+n2
+n2
+o5	#^
+o16	#-
+v0	#z
+n2
+o5	#^
+v0	#z
+n2
+x0	#initial guess
+r	#1 ranges (rhs's)
+1 0.5	#c1
+b	#1 bounds (on variables)
+3	#z
+k0	#intermediate Jacobian column lengths
+G0 1	#obj
+0 0
+""",
+                OUT.getvalue(),
+            )
+        )
+
+        OUT = io.StringIO()
+        with LoggingIntercept() as LOG:
+            nlinfo = nl_writer.NLWriter().write(
+                m, OUT, symbolic_solver_labels=True, linear_presolve=True
+            )
+        self.assertEqual(LOG.getvalue(), "")
+
+        self.assertIs(nlinfo.eliminated_vars[0][0], m.y)
+        self.assertExpressionsEqual(
+            nlinfo.eliminated_vars[0][1], LinearExpression([-1.0 * m.z])
+        )
+        self.assertEqual(nlinfo.eliminated_vars[1], (m.x, 2))
+
+        self.assertEqual(
+            *nl_diff(
+                """g3 1 1 0	# problem unknown
+ 1 0 1 0 0	#vars, constraints, objectives, ranges, eqns
+ 0 1 0 0 0 0	#nonlinear constrs, objs; ccons: lin, nonlin, nd, nzlb
+ 0 0	#network constraints: nonlinear, linear
+ 0 1 0	#nonlinear vars in constraints, objectives, both
+ 0 0 0 1	#linear network variables; functions; arith, flags
+ 0 0 0 0 0	#discrete variables: binary, integer, nonlinear (b,c,o)
+ 0 1	#nonzeros in Jacobian, obj. gradient
+ 3 1	#max name lengths: constraints, variables
+ 0 0 0 0 0	#common exprs: b,c,o,c1,o1
+O0 0	#obj
+o54	#sumlist
+3	#(n)
+o5	#^
+n2
+n2
+o5	#^
+o16	#-
+v0	#z
+n2
+o5	#^
+v0	#z
+n2
+x0	#initial guess
+r	#1 ranges (rhs's)
+b	#1 bounds (on variables)
+3	#z
+k0	#intermediate Jacobian column lengths
+G0 1	#obj
+0 0
+""",
+                OUT.getvalue(),
+            )
+        )
+
+    def test_presolve_independent_subsystem(self):
+        # This is derived from the example in #3192
+        m = ConcreteModel()
+        m.x = Var()
+        m.y = Var()
+        m.z = Var()
+        m.d = Constraint(expr=m.z == m.y)
+        m.c = Constraint(expr=m.y == m.x)
+        m.o = Objective(expr=0)
+
+        ref = """g3 1 1 0       #problem unknown
+ 0 0 1 0 0     #vars, constraints, objectives, ranges, eqns
+ 0 0 0 0 0 0   #nonlinear constrs, objs; ccons: lin, nonlin, nd, nzlb
+ 0 0   #network constraints: nonlinear, linear
+ 0 0 0 #nonlinear vars in constraints, objectives, both
+ 0 0 0 1       #linear network variables; functions; arith, flags
+ 0 0 0 0 0     #discrete variables: binary, integer, nonlinear (b,c,o)
+ 0 0   #nonzeros in Jacobian, obj. gradient
+ 1 0   #max name lengths: constraints, variables
+ 0 0 0 0 0     #common exprs: b,c,o,c1,o1
+O0 0   #o
+n0
+x0     #initial guess
+r      #0 ranges (rhs's)
+b      #0 bounds (on variables)
+k-1    #intermediate Jacobian column lengths
+"""
+
+        OUT = io.StringIO()
+        with LoggingIntercept() as LOG:
+            nlinfo = nl_writer.NLWriter().write(
+                m, OUT, symbolic_solver_labels=True, linear_presolve=True
+            )
+        self.assertEqual(
+            LOG.getvalue(),
+            "presolve identified an underdetermined independent linear subsystem "
+            "that was removed from the model.  Setting 'z' == 0\n",
+        )
+
+        self.assertEqual(*nl_diff(ref, OUT.getvalue()))
+
+        m.x.lb = 5.0
+
+        OUT = io.StringIO()
+        with LoggingIntercept() as LOG:
+            nlinfo = nl_writer.NLWriter().write(
+                m, OUT, symbolic_solver_labels=True, linear_presolve=True
+            )
+        self.assertEqual(
+            LOG.getvalue(),
+            "presolve identified an underdetermined independent linear subsystem "
+            "that was removed from the model.  Setting 'z' == 5.0\n",
+        )
+
+        self.assertEqual(*nl_diff(ref, OUT.getvalue()))
+
+        m.x.lb = -5.0
+        m.z.ub = -2.0
+
+        OUT = io.StringIO()
+        with LoggingIntercept() as LOG:
+            nlinfo = nl_writer.NLWriter().write(
+                m, OUT, symbolic_solver_labels=True, linear_presolve=True
+            )
+        self.assertEqual(
+            LOG.getvalue(),
+            "presolve identified an underdetermined independent linear subsystem "
+            "that was removed from the model.  Setting 'z' == -2.0\n",
+        )
+
+        self.assertEqual(*nl_diff(ref, OUT.getvalue()))
+
     def test_scaling(self):
         m = pyo.ConcreteModel()
         m.x = pyo.Var(initialize=0)
@@ -1969,6 +2220,554 @@ def test_named_expressions(self):
 0 0
 1 0
 2 0
+""",
+                OUT.getvalue(),
+            )
+        )
+
+    def test_discrete_var_tabulation(self):
+        # This tests an error reported in #3235
+        #
+        # Among other issues, this verifies that nonlinear discrete
+        # variables are tabulated correctly (header line 7), and that
+        # integer variables with bounds in {0, 1} are mapped to binary
+        # variables.
+        m = ConcreteModel()
+        m.p1 = Var(bounds=(0.85, 1.15))
+        m.p2 = Var(bounds=(0.68, 0.92))
+        m.c1 = Var(bounds=(-0.0, 0.7))
+        m.c2 = Var(bounds=(-0.0, 0.7))
+        m.t1 = Var(within=Binary, bounds=(0, 1))
+        m.t2 = Var(within=Binary, bounds=(0, 1))
+        m.t3 = Var(within=Binary, bounds=(0, 1))
+        m.t4 = Var(within=Binary, bounds=(0, 1))
+        m.t5 = Var(within=Integers, bounds=(0, None))
+        m.t6 = Var(within=Integers, bounds=(0, None))
+        m.x1 = Var(within=Binary)
+        m.x2 = Var(within=Integers, bounds=(0, 1))
+        m.x3 = Var(within=Integers, bounds=(0, None))
+        m.const = Constraint(
+            expr=(
+                (0.7 - (m.c1 * m.t1 + m.c2 * m.t2))
+                <= (m.p1 * m.t1 + m.p2 * m.t2 + m.p1 * m.t4 + m.t6 * m.t5)
+            )
+        )
+        m.OBJ = Objective(
+            expr=(m.p1 * m.t1 + m.p2 * m.t2 + m.p2 * m.t3 + m.x1 + m.x2 + m.x3)
+        )
+
+        OUT = io.StringIO()
+        nl_writer.NLWriter().write(m, OUT, symbolic_solver_labels=True)
+
+        self.assertEqual(
+            *nl_diff(
+                """g3 1 1 0	# problem unknown
+ 13 1 1 0 0    #vars, constraints, objectives, ranges, eqns
+ 1 1 0 0 0 0   #nonlinear constrs, objs; ccons: lin, nonlin, nd, nzlb
+ 0 0   #network constraints: nonlinear, linear
+ 9 10 4        #nonlinear vars in constraints, objectives, both
+ 0 0 0 1       #linear network variables; functions; arith, flags
+ 2 1 2 3 1     #discrete variables: binary, integer, nonlinear (b,c,o)
+ 9 8   #nonzeros in Jacobian, obj. gradient
+ 5 2   #max name lengths: constraints, variables
+ 0 0 0 0 0     #common exprs: b,c,o,c1,o1
+C0     #const
+o0     #+
+o16    #-
+o0     #+
+o2     #*
+v4     #c1
+v2     #t1
+o2     #*
+v5     #c2
+v3     #t2
+o16    #-
+o54    #sumlist
+4      #(n)
+o2     #*
+v0     #p1
+v2     #t1
+o2     #*
+v1     #p2
+v3     #t2
+o2     #*
+v0     #p1
+v6     #t4
+o2     #*
+v7     #t6
+v8     #t5
+O0 0   #OBJ
+o54    #sumlist
+3      #(n)
+o2     #*
+v0     #p1
+v2     #t1
+o2     #*
+v1     #p2
+v3     #t2
+o2     #*
+v1     #p2
+v9     #t3
+x0     #initial guess
+r      #1 ranges (rhs's)
+1 -0.7 #const
+b      #13 bounds (on variables)
+0 0.85 1.15    #p1
+0 0.68 0.92    #p2
+0 0 1  #t1
+0 0 1  #t2
+0 -0.0 0.7     #c1
+0 -0.0 0.7     #c2
+0 0 1  #t4
+2 0    #t6
+2 0    #t5
+0 0 1  #t3
+0 0 1  #x1
+0 0 1  #x2
+2 0    #x3
+k12    #intermediate Jacobian column lengths
+1
+2
+3
+4
+5
+6
+7
+8
+9
+9
+9
+9
+J0 9   #const
+0 0
+1 0
+2 0
+3 0
+4 0
+5 0
+6 0
+7 0
+8 0
+G0 8   #OBJ
+0 0
+1 0
+2 0
+3 0
+9 0
+10 1
+11 1
+12 1
+""",
+                OUT.getvalue(),
+            )
+        )
+
+    def test_presolve_fixes_nl_defined_variables(self):
+        # This tests a workaround for a bug in the ASL where defined
+        # variables with constant expressions in the NL portion are not
+        # evaluated correctly.
+        m = ConcreteModel()
+        m.x = Var()
+        m.y = Var(bounds=(3, None))
+        m.z = Var(bounds=(None, 3))
+        m.e = Expression(expr=m.x + m.y * m.z + m.y**2 + 3 / m.z)
+        m.c1 = Constraint(expr=m.y * m.e + m.x >= 0)
+        m.c2 = Constraint(expr=m.y == m.z)
+
+        OUT = io.StringIO()
+        nl_writer.NLWriter().write(
+            m,
+            OUT,
+            symbolic_solver_labels=True,
+            linear_presolve=True,
+            export_defined_variables=True,
+        )
+        self.assertEqual(
+            *nl_diff(
+                """g3 1 1 0	# problem unknown
+ 1 1 0 0 0	#vars, constraints, objectives, ranges, eqns
+ 1 0 0 0 0 0	#nonlinear constrs, objs; ccons: lin, nonlin, nd, nzlb
+ 0 0	#network constraints: nonlinear, linear
+ 1 0 0	#nonlinear vars in constraints, objectives, both
+ 0 0 0 1	#linear network variables; functions; arith, flags
+ 0 0 0 0 0	#discrete variables: binary, integer, nonlinear (b,c,o)
+ 1 0	#nonzeros in Jacobian, obj. gradient
+ 2 1	#max name lengths: constraints, variables
+ 0 0 0 1 0	#common exprs: b,c,o,c1,o1
+V1 1 1	#e
+0 1
+n19
+C0	#c1
+o2	#*
+n3
+v1	#e
+x0	#initial guess
+r	#1 ranges (rhs's)
+2 0	#c1
+b	#1 bounds (on variables)
+3	#x
+k0	#intermediate Jacobian column lengths
+J0 1	#c1
+0 1
+""",
+                OUT.getvalue(),
+            )
+        )
+
+        OUT = io.StringIO()
+        nl_writer.NLWriter().write(
+            m,
+            OUT,
+            symbolic_solver_labels=True,
+            linear_presolve=True,
+            export_defined_variables=False,
+        )
+        self.assertEqual(
+            *nl_diff(
+                """g3 1 1 0	# problem unknown
+ 1 1 0 0 0	#vars, constraints, objectives, ranges, eqns
+ 1 0 0 0 0 0	#nonlinear constrs, objs; ccons: lin, nonlin, nd, nzlb
+ 0 0	#network constraints: nonlinear, linear
+ 1 0 0	#nonlinear vars in constraints, objectives, both
+ 0 0 0 1	#linear network variables; functions; arith, flags
+ 0 0 0 0 0	#discrete variables: binary, integer, nonlinear (b,c,o)
+ 1 0	#nonzeros in Jacobian, obj. gradient
+ 2 1	#max name lengths: constraints, variables
+ 0 0 0 0 0	#common exprs: b,c,o,c1,o1
+C0	#c1
+o2	#*
+n3
+o0	#+
+v0	#x
+o54	#sumlist
+3	#(n)
+o2	#*
+n3
+n3
+o5	#^
+n3
+n2
+o3	#/
+n3
+n3
+x0	#initial guess
+r	#1 ranges (rhs's)
+2 0	#c1
+b	#1 bounds (on variables)
+3	#x
+k0	#intermediate Jacobian column lengths
+J0 1	#c1
+0 1
+""",
+                OUT.getvalue(),
+            )
+        )
+
+        OUT = io.StringIO()
+        nl_writer.NLWriter().write(
+            m,
+            OUT,
+            symbolic_solver_labels=True,
+            linear_presolve=False,
+            export_defined_variables=True,
+        )
+        self.assertEqual(
+            *nl_diff(
+                """g3 1 1 0	# problem unknown
+ 3 2 0 0 1	#vars, constraints, objectives, ranges, eqns
+ 1 0 0 0 0 0	#nonlinear constrs, objs; ccons: lin, nonlin, nd, nzlb
+ 0 0	#network constraints: nonlinear, linear
+ 3 0 0	#nonlinear vars in constraints, objectives, both
+ 0 0 0 1	#linear network variables; functions; arith, flags
+ 0 0 0 0 0	#discrete variables: binary, integer, nonlinear (b,c,o)
+ 5 0	#nonzeros in Jacobian, obj. gradient
+ 2 1	#max name lengths: constraints, variables
+ 0 0 0 2 0	#common exprs: b,c,o,c1,o1
+V3 0 1	#nl(e)
+o54	#sumlist
+3	#(n)
+o2	#*
+v0	#y
+v2	#z
+o5	#^
+v0	#y
+n2
+o3	#/
+n3
+v2	#z
+V4 1 1	#e
+1 1
+v3	#nl(e)
+C0	#c1
+o2	#*
+v0	#y
+v4	#e
+C1	#c2
+n0
+x0	#initial guess
+r	#2 ranges (rhs's)
+2 0	#c1
+4 0	#c2
+b	#3 bounds (on variables)
+2 3	#y
+3	#x
+1 3	#z
+k2	#intermediate Jacobian column lengths
+2
+3
+J0 3	#c1
+0 0
+1 1
+2 0
+J1 2	#c2
+0 1
+2 -1
+""",
+                OUT.getvalue(),
+            )
+        )
+
+    def test_presolve_fixes_nl_external_function(self):
+        # This tests a workaround for a bug in the ASL where external
+        # functions with constant argument expressions are not
+        # evaluated correctly.
+        DLL = find_GSL()
+        if not DLL:
+            self.skipTest("Could not find the amplgsl.dll library")
+
+        m = ConcreteModel()
+        m.hypot = ExternalFunction(library=DLL, function="gsl_hypot")
+        m.p = Param(initialize=1, mutable=True)
+        m.x = Var(bounds=(None, 3))
+        m.y = Var(bounds=(3, None))
+        m.z = Var(initialize=1)
+        m.o = Objective(expr=m.z**2 * m.hypot(m.p * m.x, m.p + m.y) ** 2)
+        m.c = Constraint(expr=m.x == m.y)
+
+        OUT = io.StringIO()
+        nl_writer.NLWriter().write(
+            m, OUT, symbolic_solver_labels=True, linear_presolve=False
+        )
+        self.assertEqual(
+            *nl_diff(
+                """g3 1 1 0       #problem unknown
+ 3 1 1 0 1     #vars, constraints, objectives, ranges, eqns
+ 0 1 0 0 0 0   #nonlinear constrs, objs; ccons: lin, nonlin, nd, nzlb
+ 0 0   #network constraints: nonlinear, linear
+ 0 3 0 #nonlinear vars in constraints, objectives, both
+ 0 1 0 1       #linear network variables; functions; arith, flags
+ 0 0 0 0 0     #discrete variables: binary, integer, nonlinear (b,c,o)
+ 2 3   #nonzeros in Jacobian, obj. gradient
+ 1 1   #max name lengths: constraints, variables
+ 0 0 0 0 0     #common exprs: b,c,o,c1,o1
+F0 1 -1 gsl_hypot
+C0     #c
+n0
+O0 0   #o
+o2     #*
+o5     #^
+v0     #z
+n2
+o5     #^
+f0 2   #hypot
+v1     #x
+o0     #+
+v2     #y
+n1
+n2
+x1     #initial guess
+0 1    #z
+r      #1 ranges (rhs's)
+4 0    #c
+b      #3 bounds (on variables)
+3      #z
+1 3    #x
+2 3    #y
+k2     #intermediate Jacobian column lengths
+0
+1
+J0 2   #c
+1 1
+2 -1
+G0 3   #o
+0 0
+1 0
+2 0
+""",
+                OUT.getvalue(),
+            )
+        )
+
+        OUT = io.StringIO()
+        nl_writer.NLWriter().write(
+            m, OUT, symbolic_solver_labels=True, linear_presolve=True
+        )
+        self.assertEqual(
+            *nl_diff(
+                """g3 1 1 0       #problem unknown
+ 1 0 1 0 0     #vars, constraints, objectives, ranges, eqns
+ 0 1 0 0 0 0   #nonlinear constrs, objs; ccons: lin, nonlin, nd, nzlb
+ 0 0   #network constraints: nonlinear, linear
+ 0 1 0 #nonlinear vars in constraints, objectives, both
+ 0 1 0 1       #linear network variables; functions; arith, flags
+ 0 0 0 0 0     #discrete variables: binary, integer, nonlinear (b,c,o)
+ 0 1   #nonzeros in Jacobian, obj. gradient
+ 1 1   #max name lengths: constraints, variables
+ 0 0 0 0 0     #common exprs: b,c,o,c1,o1
+F0 1 -1 gsl_hypot
+O0 0   #o
+o2     #*
+o5     #^
+v0     #z
+n2
+o5     #^
+f0 2   #hypot
+n3
+n4
+n2
+x1     #initial guess
+0 1    #z
+r      #0 ranges (rhs's)
+b      #1 bounds (on variables)
+3      #z
+k0     #intermediate Jacobian column lengths
+G0 1   #o
+0 0
+""",
+                OUT.getvalue(),
+            )
+        )
+
+    def test_presolve_defined_var_to_const(self):
+        # This test is derived from a step in an IDAES initialization
+        # where the presolver is able to fix enough variables to cause
+        # the defined variable to be reduced to a constant.  We must not
+        # emit the defined variable (because doing so generates an error
+        # in the ASL)
+        m = ConcreteModel()
+        m.eq = Var(initialize=100)
+        m.co2 = Var()
+        m.n2 = Var()
+        m.E = Expression(expr=60 / (3 * m.co2 - 4 * m.n2 - 5))
+        m.con1 = Constraint(expr=m.co2 == 6)
+        m.con2 = Constraint(expr=m.n2 == 7)
+        m.con3 = Constraint(expr=8 / m.E == m.eq)
+
+        OUT = io.StringIO()
+        nl_writer.NLWriter().write(
+            m, OUT, symbolic_solver_labels=True, linear_presolve=True
+        )
+        # Note that the presolve will end up recognizing con3 as a
+        # linear constraint; however, it does not do so until processing
+        # the constraints after presolve (so the constraint is not
+        # actually removed and the eq variable still appears in the model)
+        self.assertEqual(
+            *nl_diff(
+                """g3 1 1 0	#problem unknown
+ 1 1 0 0 1	#vars, constraints, objectives, ranges, eqns
+ 0 0 0 0 0 0	#nonlinear constrs, objs; ccons: lin, nonlin, nd, nzlb
+ 0 0	#network constraints: nonlinear, linear
+ 0 0 0	#nonlinear vars in constraints, objectives, both
+ 0 0 0 1	#linear network variables; functions; arith, flags
+ 0 0 0 0 0	#discrete variables: binary, integer, nonlinear (b,c,o)
+ 1 0	#nonzeros in Jacobian, obj. gradient
+ 4 2	#max name lengths: constraints, variables
+ 0 0 0 0 0	#common exprs: b,c,o,c1,o1
+C0	#con3
+n0
+x1	#initial guess
+0 100	#eq
+r	#1 ranges (rhs's)
+4 2.0	#con3
+b	#1 bounds (on variables)
+3	#eq
+k0	#intermediate Jacobian column lengths
+J0 1	#con3
+0 -1
+""",
+                OUT.getvalue(),
+            )
+        )
+
+    def test_presolve_check_invalid_monomial_constraints(self):
+        # This checks issue #3272
+        m = ConcreteModel()
+        m.x = Var()
+        m.c = Constraint(expr=m.x == 5)
+        m.d = Constraint(expr=m.x >= 10)
+
+        OUT = io.StringIO()
+        with self.assertRaisesRegex(
+            nl_writer.InfeasibleConstraintException,
+            r"model contains a trivially infeasible constraint 'd' "
+            r"\(fixed body value 5.0 outside bounds \[10, None\]\)\.",
+        ):
+            nl_writer.NLWriter().write(m, OUT, linear_presolve=True)
+
+    def test_nested_external_expressions(self):
+        # This tests nested external functions in a single expression
+        DLL = find_GSL()
+        if not DLL:
+            self.skipTest("Could not find the amplgsl.dll library")
+
+        m = ConcreteModel()
+        m.hypot = ExternalFunction(library=DLL, function="gsl_hypot")
+        m.p = Param(initialize=1, mutable=True)
+        m.x = Var(bounds=(None, 3))
+        m.y = Var(bounds=(3, None))
+        m.z = Var(initialize=1)
+        m.o = Objective(expr=m.z**2 * m.hypot(m.z, m.hypot(m.x, m.y)) ** 2)
+        m.c = Constraint(expr=m.x == m.y)
+
+        OUT = io.StringIO()
+        nl_writer.NLWriter().write(
+            m, OUT, symbolic_solver_labels=True, linear_presolve=False
+        )
+        self.assertEqual(
+            *nl_diff(
+                """g3 1 1 0	#problem unknown
+ 3 1 1 0 1	#vars, constraints, objectives, ranges, eqns
+ 0 1 0 0 0 0	#nonlinear constrs, objs; ccons: lin, nonlin, nd, nzlb
+ 0 0	#network constraints: nonlinear, linear
+ 0 3 0	#nonlinear vars in constraints, objectives, both
+ 0 1 0 1	#linear network variables; functions; arith, flags
+ 0 0 0 0 0	#discrete variables: binary, integer, nonlinear (b,c,o)
+ 2 3	#nonzeros in Jacobian, obj. gradient
+ 1 1	#max name lengths: constraints, variables
+ 0 0 0 0 0	#common exprs: b,c,o,c1,o1
+F0 1 -1 gsl_hypot
+C0	#c
+n0
+O0 0	#o
+o2	#*
+o5	#^
+v0	#z
+n2
+o5	#^
+f0 2	#hypot
+v0	#z
+f0 2	#hypot
+v1	#x
+v2	#y
+n2
+x1	#initial guess
+0 1	#z
+r	#1 ranges (rhs's)
+4 0	#c
+b	#3 bounds (on variables)
+3	#z
+1 3	#x
+2 3	#y
+k2	#intermediate Jacobian column lengths
+0
+1
+J0 2	#c
+1 1
+2 -1
+G0 3	#o
+0 0
+1 0
+2 0
 """,
                 OUT.getvalue(),
             )
diff --git a/pyomo/repn/tests/ampl/test_suffixes.py b/pyomo/repn/tests/ampl/test_suffixes.py
index e73060e7e8c..1372da68bdc 100644
--- a/pyomo/repn/tests/ampl/test_suffixes.py
+++ b/pyomo/repn/tests/ampl/test_suffixes.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/baron/__init__.py b/pyomo/repn/tests/baron/__init__.py
index 030f46eaca8..c693bb8accd 100644
--- a/pyomo/repn/tests/baron/__init__.py
+++ b/pyomo/repn/tests/baron/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/baron/small14a_testCase.py b/pyomo/repn/tests/baron/small14a_testCase.py
index 72190756dc7..b2cf5afcb72 100644
--- a/pyomo/repn/tests/baron/small14a_testCase.py
+++ b/pyomo/repn/tests/baron/small14a_testCase.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/baron/test_baron.py b/pyomo/repn/tests/baron/test_baron.py
index 348ad6036fb..6f22f26cd38 100644
--- a/pyomo/repn/tests/baron/test_baron.py
+++ b/pyomo/repn/tests/baron/test_baron.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/baron/test_baron_comparison.py b/pyomo/repn/tests/baron/test_baron_comparison.py
index 7c480321624..1b394f6a5b1 100644
--- a/pyomo/repn/tests/baron/test_baron_comparison.py
+++ b/pyomo/repn/tests/baron/test_baron_comparison.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/cpxlp/__init__.py b/pyomo/repn/tests/cpxlp/__init__.py
index 8ffbfd52054..f216a76f48b 100644
--- a/pyomo/repn/tests/cpxlp/__init__.py
+++ b/pyomo/repn/tests/cpxlp/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/cpxlp/test_cpxlp.py b/pyomo/repn/tests/cpxlp/test_cpxlp.py
index 28c9043a8de..567c5184517 100644
--- a/pyomo/repn/tests/cpxlp/test_cpxlp.py
+++ b/pyomo/repn/tests/cpxlp/test_cpxlp.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/cpxlp/test_lpv2.py b/pyomo/repn/tests/cpxlp/test_lpv2.py
index 336939a4d7d..fbef24c77c3 100644
--- a/pyomo/repn/tests/cpxlp/test_lpv2.py
+++ b/pyomo/repn/tests/cpxlp/test_lpv2.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/diffutils.py b/pyomo/repn/tests/diffutils.py
index 24188d46c86..c346f8c48b2 100644
--- a/pyomo/repn/tests/diffutils.py
+++ b/pyomo/repn/tests/diffutils.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/gams/__init__.py b/pyomo/repn/tests/gams/__init__.py
index 8d13c4ffb99..e548666fd72 100644
--- a/pyomo/repn/tests/gams/__init__.py
+++ b/pyomo/repn/tests/gams/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/gams/small14a_testCase.py b/pyomo/repn/tests/gams/small14a_testCase.py
index c7e3e0805ea..1efdd1baa25 100644
--- a/pyomo/repn/tests/gams/small14a_testCase.py
+++ b/pyomo/repn/tests/gams/small14a_testCase.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/gams/test_gams.py b/pyomo/repn/tests/gams/test_gams.py
index e6b729e5dfc..e3304e18491 100644
--- a/pyomo/repn/tests/gams/test_gams.py
+++ b/pyomo/repn/tests/gams/test_gams.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/gams/test_gams_comparison.py b/pyomo/repn/tests/gams/test_gams_comparison.py
index 4e530b10d43..42fa9f71dda 100644
--- a/pyomo/repn/tests/gams/test_gams_comparison.py
+++ b/pyomo/repn/tests/gams/test_gams_comparison.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/lp_diff.py b/pyomo/repn/tests/lp_diff.py
index 23b24f8b51b..2c119d72c6f 100644
--- a/pyomo/repn/tests/lp_diff.py
+++ b/pyomo/repn/tests/lp_diff.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/mps/__init__.py b/pyomo/repn/tests/mps/__init__.py
index 1a8a69a1409..effc182aa1c 100644
--- a/pyomo/repn/tests/mps/__init__.py
+++ b/pyomo/repn/tests/mps/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/mps/test_mps.py b/pyomo/repn/tests/mps/test_mps.py
index 9be45a17870..ff7981b391c 100644
--- a/pyomo/repn/tests/mps/test_mps.py
+++ b/pyomo/repn/tests/mps/test_mps.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/nl_diff.py b/pyomo/repn/tests/nl_diff.py
index e96d6f6357b..aa2b4519db3 100644
--- a/pyomo/repn/tests/nl_diff.py
+++ b/pyomo/repn/tests/nl_diff.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/test_linear.py b/pyomo/repn/tests/test_linear.py
index 0eec8a1541c..d88ddf96baa 100644
--- a/pyomo/repn/tests/test_linear.py
+++ b/pyomo/repn/tests/test_linear.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -1436,6 +1436,22 @@ def test_errors_propagate_nan(self):
         m.z = Var()
         m.y.fix(1)
 
+        expr = (m.x + 1) / m.p
+        cfg = VisitorConfig()
+        with LoggingIntercept() as LOG:
+            repn = LinearRepnVisitor(*cfg).walk_expression(expr)
+        self.assertEqual(
+            LOG.getvalue(),
+            "Exception encountered evaluating expression 'div(1, 0)'\n"
+            "\tmessage: division by zero\n"
+            "\texpression: (x + 1)/p\n",
+        )
+        self.assertEqual(repn.multiplier, 1)
+        self.assertEqual(str(repn.constant), 'InvalidNumber(nan)')
+        self.assertEqual(len(repn.linear), 1)
+        self.assertEqual(str(repn.linear[id(m.x)]), 'InvalidNumber(nan)')
+        self.assertEqual(repn.nonlinear, None)
+
         expr = m.y + m.x + m.z + ((3 * m.x) / m.p) / m.y
         cfg = VisitorConfig()
         with LoggingIntercept() as LOG:
@@ -1517,7 +1533,7 @@ def test_type_registrations(self):
                 bcd.register_dispatcher(visitor, 5), (False, (linear._CONSTANT, 5))
             )
             self.assertEqual(len(bcd), 1)
-            self.assertIs(bcd[int], bcd._before_native)
+            self.assertIs(bcd[int], bcd._before_native_numeric)
             # complex type
             self.assertEqual(
                 bcd.register_dispatcher(visitor, 5j), (False, (linear._CONSTANT, 5j))
@@ -1589,7 +1605,7 @@ def test_to_expression(self):
         expr.constant = 0
         expr.linear[id(m.x)] = 0
         expr.linear[id(m.y)] = 0
-        assertExpressionsEqual(self, expr.to_expression(visitor), LinearExpression())
+        assertExpressionsEqual(self, expr.to_expression(visitor), 0)
 
     @unittest.skipUnless(numpy_available, "Test requires numpy")
     def test_nonnumeric(self):
@@ -1643,7 +1659,7 @@ def test_zero_elimination(self):
         self.assertEqual(repn.multiplier, 1)
         self.assertEqual(repn.constant, 0)
         self.assertEqual(repn.linear, {})
-        self.assertEqual(repn.nonlinear, None)
+        self.assertIsNone(repn.nonlinear)
 
         m.p = Param(mutable=True, within=Any, initialize=None)
         e = m.p * m.x[0] + m.p * m.x[1] * m.x[2] + m.p * log(m.x[3])
diff --git a/pyomo/repn/tests/test_parameterized_linear.py b/pyomo/repn/tests/test_parameterized_linear.py
new file mode 100644
index 00000000000..624f8390d16
--- /dev/null
+++ b/pyomo/repn/tests/test_parameterized_linear.py
@@ -0,0 +1,552 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+from pyomo.common.log import LoggingIntercept
+import pyomo.common.unittest as unittest
+from pyomo.core.expr.compare import assertExpressionsEqual
+from pyomo.environ import Any, Binary, ConcreteModel, log, Param, Var
+from pyomo.repn.parameterized_linear import ParameterizedLinearRepnVisitor
+from pyomo.repn.tests.test_linear import VisitorConfig
+from pyomo.repn.util import InvalidNumber
+
+
+class TestParameterizedLinearRepnVisitor(unittest.TestCase):
+    def make_model(self):
+        m = ConcreteModel()
+        m.x = Var(bounds=(0, 45))
+        m.y = Var(domain=Binary)
+        m.z = Var()
+
+        return m
+
+    def test_walk_sum(self):
+        m = self.make_model()
+        e = m.x + m.y
+        cfg = VisitorConfig()
+        visitor = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.y, m.z])
+
+        repn = visitor.walk_expression(e)
+
+        self.assertIsNone(repn.nonlinear)
+        self.assertEqual(len(repn.linear), 1)
+        self.assertIn(id(m.x), repn.linear)
+        self.assertEqual(repn.linear[id(m.x)], 1)
+        self.assertIs(repn.constant, m.y)
+        self.assertEqual(repn.multiplier, 1)
+        assertExpressionsEqual(self, repn.to_expression(visitor), m.x + m.y)
+
+    def test_walk_triple_sum(self):
+        m = self.make_model()
+        e = m.x + m.z * m.y + m.z
+
+        cfg = VisitorConfig()
+        visitor = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.z])
+
+        repn = visitor.walk_expression(e)
+
+        self.assertIsNone(repn.nonlinear)
+        self.assertEqual(len(repn.linear), 2)
+        self.assertIn(id(m.x), repn.linear)
+        self.assertIn(id(m.y), repn.linear)
+        self.assertEqual(repn.linear[id(m.x)], 1)
+        self.assertIs(repn.linear[id(m.y)], m.z)
+        self.assertIs(repn.constant, m.z)
+        self.assertEqual(repn.multiplier, 1)
+        assertExpressionsEqual(self, repn.to_expression(visitor), m.x + m.z * m.y + m.z)
+
+    def test_sum_two_of_the_same(self):
+        # This hits the mult == 1 and vid in dest_dict case in _merge_dict
+        m = self.make_model()
+        e = m.x + m.x
+        cfg = VisitorConfig()
+        visitor = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.z])
+
+        repn = visitor.walk_expression(e)
+
+        self.assertIsNone(repn.nonlinear)
+        self.assertEqual(len(repn.linear), 1)
+        self.assertIn(id(m.x), repn.linear)
+        self.assertEqual(repn.linear[id(m.x)], 2)
+        self.assertEqual(repn.constant, 0)
+        self.assertEqual(repn.multiplier, 1)
+        assertExpressionsEqual(self, repn.to_expression(visitor), 2 * m.x)
+
+    def test_sum_with_mult_0(self):
+        m = self.make_model()
+        e = 0 * m.x + m.x - m.y
+
+        cfg = VisitorConfig()
+        visitor = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.y, m.z])
+
+        repn = visitor.walk_expression(e)
+        self.assertIsNone(repn.nonlinear)
+        self.assertEqual(len(repn.linear), 1)
+        self.assertIn(id(m.x), repn.linear)
+        self.assertEqual(repn.linear[id(m.x)], 1)
+        assertExpressionsEqual(self, repn.constant, -m.y)
+        self.assertEqual(repn.multiplier, 1)
+        assertExpressionsEqual(self, repn.to_expression(visitor), m.x - m.y)
+
+    def test_sum_nonlinear_to_linear(self):
+        m = self.make_model()
+        e = m.y * m.x**2 + m.y * m.x - 3
+
+        cfg = VisitorConfig()
+        visitor = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.y, m.z])
+
+        repn = visitor.walk_expression(e)
+        assertExpressionsEqual(self, repn.nonlinear, m.y * m.x**2)
+        self.assertEqual(len(repn.linear), 1)
+        self.assertIn(id(m.x), repn.linear)
+        self.assertIs(repn.linear[id(m.x)], m.y)
+        self.assertEqual(repn.constant, -3)
+        self.assertEqual(repn.multiplier, 1)
+        assertExpressionsEqual(
+            self, repn.to_expression(visitor), m.y * m.x**2 + m.y * m.x - 3
+        )
+
+    def test_sum_nonlinear_to_nonlinear(self):
+        m = self.make_model()
+        e = m.x**3 + 3 + m.x**2
+
+        cfg = VisitorConfig()
+        visitor = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.y, m.z])
+
+        repn = visitor.walk_expression(e)
+        assertExpressionsEqual(self, repn.nonlinear, m.x**3 + m.x**2)
+        self.assertEqual(repn.constant, 3)
+        self.assertEqual(repn.multiplier, 1)
+        assertExpressionsEqual(self, repn.to_expression(visitor), m.x**3 + m.x**2 + 3)
+
+    def test_sum_to_linear_expr(self):
+        m = self.make_model()
+        e = m.x + m.y * (m.x + 5)
+
+        cfg = VisitorConfig()
+        visitor = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.y, m.z])
+
+        repn = visitor.walk_expression(e)
+        self.assertEqual(len(repn.linear), 1)
+        self.assertIn(id(m.x), repn.linear)
+        assertExpressionsEqual(self, repn.linear[id(m.x)], 1 + m.y)
+        assertExpressionsEqual(self, repn.constant, m.y * 5)
+        self.assertEqual(repn.multiplier, 1)
+        assertExpressionsEqual(
+            self, repn.to_expression(visitor), (1 + m.y) * m.x + m.y * 5
+        )
+
+    def test_bilinear_term(self):
+        m = self.make_model()
+        e = m.x * m.y
+        cfg = VisitorConfig()
+        visitor = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.y, m.z])
+
+        repn = visitor.walk_expression(e)
+
+        self.assertIsNone(repn.nonlinear)
+        self.assertEqual(len(repn.linear), 1)
+        self.assertIn(id(m.x), repn.linear)
+        self.assertIs(repn.linear[id(m.x)], m.y)
+        self.assertEqual(repn.constant, 0)
+        self.assertEqual(repn.multiplier, 1)
+        assertExpressionsEqual(self, repn.to_expression(visitor), m.y * m.x)
+
+    def test_distributed_bilinear_term(self):
+        m = self.make_model()
+        e = m.y * (m.x + 7)
+        cfg = VisitorConfig()
+        visitor = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.y, m.z])
+
+        repn = visitor.walk_expression(e)
+
+        self.assertIsNone(repn.nonlinear)
+        self.assertEqual(len(repn.linear), 1)
+        self.assertIn(id(m.x), repn.linear)
+        self.assertIs(repn.linear[id(m.x)], m.y)
+        assertExpressionsEqual(self, repn.constant, m.y * 7)
+        self.assertEqual(repn.multiplier, 1)
+        assertExpressionsEqual(self, repn.to_expression(visitor), m.y * m.x + m.y * 7)
+
+    def test_monomial(self):
+        m = self.make_model()
+        e = 45 * m.y
+        cfg = VisitorConfig()
+        visitor = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.x, m.z])
+
+        repn = visitor.walk_expression(e)
+
+        self.assertIsNone(repn.nonlinear)
+        self.assertEqual(len(repn.linear), 1)
+        self.assertIn(id(m.y), repn.linear)
+        self.assertEqual(repn.linear[id(m.y)], 45)
+        self.assertEqual(repn.constant, 0)
+        self.assertEqual(repn.multiplier, 1)
+        assertExpressionsEqual(self, repn.to_expression(visitor), 45 * m.y)
+
+    def test_constant(self):
+        m = self.make_model()
+        e = 45 * m.y
+        cfg = VisitorConfig()
+        visitor = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.y, m.z])
+
+        repn = visitor.walk_expression(e)
+
+        self.assertIsNone(repn.nonlinear)
+        self.assertEqual(len(repn.linear), 0)
+        assertExpressionsEqual(self, repn.constant, 45 * m.y)
+        self.assertEqual(repn.multiplier, 1)
+        assertExpressionsEqual(self, repn.to_expression(visitor), 45 * m.y)
+
+    def test_fixed_var(self):
+        m = self.make_model()
+        m.x.fix(42)
+        e = (m.y**2) * (m.x + m.x**2)
+
+        cfg = VisitorConfig()
+        visitor = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.y, m.z])
+
+        repn = visitor.walk_expression(e)
+
+        self.assertIsNone(repn.nonlinear)
+        self.assertEqual(len(repn.linear), 0)
+        assertExpressionsEqual(self, repn.constant, (m.y**2) * 1806)
+        self.assertEqual(repn.multiplier, 1)
+        assertExpressionsEqual(self, repn.to_expression(visitor), (m.y**2) * 1806)
+
+    def test_nonlinear(self):
+        m = self.make_model()
+        e = (m.y * log(m.x)) * (m.y + 2) / m.x
+
+        cfg = VisitorConfig()
+        visitor = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.y, m.z])
+
+        repn = visitor.walk_expression(e)
+
+        self.assertEqual(len(repn.linear), 0)
+        self.assertEqual(repn.multiplier, 1)
+        assertExpressionsEqual(self, repn.nonlinear, log(m.x) * (m.y * (m.y + 2)) / m.x)
+        assertExpressionsEqual(
+            self, repn.to_expression(visitor), log(m.x) * (m.y * (m.y + 2)) / m.x
+        )
+
+    def test_finalize(self):
+        m = self.make_model()
+        m.w = Var()
+
+        e = m.x + 2 * m.w**2 * m.y - m.x - m.w * m.z
+
+        cfg = VisitorConfig()
+        repn = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.w]).walk_expression(e)
+        self.assertEqual(cfg.subexpr, {})
+        self.assertEqual(cfg.var_map, {id(m.x): m.x, id(m.y): m.y, id(m.z): m.z})
+        self.assertEqual(cfg.var_order, {id(m.x): 0, id(m.y): 1, id(m.z): 2})
+        self.assertEqual(repn.multiplier, 1)
+        self.assertEqual(repn.constant, 0)
+        self.assertEqual(len(repn.linear), 2)
+        self.assertIn(id(m.y), repn.linear)
+        assertExpressionsEqual(self, repn.linear[id(m.y)], 2 * m.w**2)
+        self.assertIn(id(m.z), repn.linear)
+        assertExpressionsEqual(self, repn.linear[id(m.z)], -m.w)
+        self.assertEqual(repn.nonlinear, None)
+
+        e *= 5
+
+        cfg = VisitorConfig()
+        repn = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.w]).walk_expression(e)
+        self.assertEqual(cfg.subexpr, {})
+        self.assertEqual(cfg.var_map, {id(m.x): m.x, id(m.y): m.y, id(m.z): m.z})
+        self.assertEqual(cfg.var_order, {id(m.x): 0, id(m.y): 1, id(m.z): 2})
+        self.assertEqual(repn.multiplier, 1)
+        self.assertEqual(repn.constant, 0)
+        self.assertEqual(len(repn.linear), 2)
+        self.assertIn(id(m.y), repn.linear)
+        assertExpressionsEqual(self, repn.linear[id(m.y)], 5 * (2 * m.w**2))
+        self.assertIn(id(m.z), repn.linear)
+        assertExpressionsEqual(self, repn.linear[id(m.z)], -5 * m.w)
+        self.assertEqual(repn.nonlinear, None)
+
+        e = 5 * (m.w * m.y + m.z**2 + 3 * m.w * m.y**3)
+
+        cfg = VisitorConfig()
+        repn = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.w]).walk_expression(e)
+        self.assertEqual(cfg.subexpr, {})
+        self.assertEqual(cfg.var_map, {id(m.y): m.y, id(m.z): m.z})
+        self.assertEqual(cfg.var_order, {id(m.y): 0, id(m.z): 1})
+        self.assertEqual(repn.multiplier, 1)
+        self.assertEqual(repn.constant, 0)
+        self.assertEqual(len(repn.linear), 1)
+        self.assertIn(id(m.y), repn.linear)
+        assertExpressionsEqual(self, repn.linear[id(m.y)], 5 * m.w)
+        assertExpressionsEqual(self, repn.nonlinear, (m.z**2 + 3 * m.w * m.y**3) * 5)
+
+    def test_ANY_over_constant_division(self):
+        m = ConcreteModel()
+        m.p = Param(mutable=True, initialize=2, domain=Any)
+        m.x = Var()
+        m.z = Var()
+        m.y = Var()
+        # We will use the fixed value regardless of the fact that we aren't
+        # treating this as a Var.
+        m.y.fix(1)
+
+        expr = m.y + m.x + m.z + ((3 * m.z * m.x) / m.p) / m.y
+        cfg = VisitorConfig()
+        repn = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.y, m.z]).walk_expression(
+            expr
+        )
+
+        self.assertEqual(repn.multiplier, 1)
+        assertExpressionsEqual(self, repn.constant, 1 + m.z)
+        self.assertEqual(len(repn.linear), 1)
+        assertExpressionsEqual(self, repn.linear[id(m.x)], 1 + 1.5 * m.z)
+        self.assertEqual(repn.nonlinear, None)
+
+    def test_errors_propagate_nan(self):
+        m = ConcreteModel()
+        m.p = Param(mutable=True, initialize=0, domain=Any)
+        m.x = Var()
+        m.z = Var()
+        m.y = Var()
+        m.y.fix(1)
+
+        expr = m.y + m.x + m.z + ((3 * m.z * m.x) / m.p) / m.y
+        cfg = VisitorConfig()
+        with LoggingIntercept() as LOG:
+            repn = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.y, m.z]).walk_expression(
+                expr
+            )
+        self.assertEqual(
+            LOG.getvalue(),
+            "Exception encountered evaluating expression 'div(3*z, 0)'\n"
+            "\tmessage: division by zero\n"
+            "\texpression: 3*z*x/p\n",
+        )
+        self.assertEqual(repn.multiplier, 1)
+        assertExpressionsEqual(self, repn.constant, 1 + m.z)
+        self.assertEqual(len(repn.linear), 1)
+        self.assertIsInstance(repn.linear[id(m.x)], InvalidNumber)
+        assertExpressionsEqual(self, repn.linear[id(m.x)].value, 1 + float('nan'))
+        self.assertEqual(repn.nonlinear, None)
+
+        m.y.fix(None)
+        expr = m.z * log(m.y) + 3
+        repn = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.y, m.z]).walk_expression(
+            expr
+        )
+        self.assertEqual(repn.multiplier, 1)
+        self.assertIsInstance(repn.constant, InvalidNumber)
+        assertExpressionsEqual(self, repn.constant.value, float('nan') * m.z + 3)
+        self.assertEqual(repn.linear, {})
+        self.assertEqual(repn.nonlinear, None)
+
+    def test_negation_constant(self):
+        m = self.make_model()
+        e = -(m.y * m.z + 17)
+
+        cfg = VisitorConfig()
+        repn = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.y, m.z]).walk_expression(e)
+
+        self.assertEqual(len(repn.linear), 0)
+        self.assertEqual(repn.multiplier, 1)
+        assertExpressionsEqual(self, repn.constant, -1 * (m.y * m.z + 17))
+        self.assertIsNone(repn.nonlinear)
+
+    def test_product_nonlinear(self):
+        m = self.make_model()
+        e = (m.x**2) * (log(m.y) * m.z**4) * m.y
+        cfg = VisitorConfig()
+        repn = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.y]).walk_expression(e)
+
+        self.assertEqual(len(repn.linear), 0)
+        self.assertEqual(repn.multiplier, 1)
+        self.assertEqual(repn.constant, 0)
+        assertExpressionsEqual(
+            self, repn.nonlinear, (m.x**2) * (m.z**4 * log(m.y)) * m.y
+        )
+
+    def test_division_pseudo_constant_constant(self):
+        m = self.make_model()
+        e = m.x / 4 + m.y
+
+        cfg = VisitorConfig()
+        repn = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.x]).walk_expression(e)
+
+        self.assertEqual(len(repn.linear), 1)
+        self.assertIn(id(m.y), repn.linear)
+        self.assertEqual(repn.linear[id(m.y)], 1)
+        self.assertEqual(repn.multiplier, 1)
+        assertExpressionsEqual(self, repn.constant, m.x / 4)
+        self.assertIsNone(repn.nonlinear)
+
+        e = 4 / m.x + m.y
+        cfg = VisitorConfig()
+        repn = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.x]).walk_expression(e)
+
+        self.assertEqual(len(repn.linear), 1)
+        self.assertIn(id(m.y), repn.linear)
+        self.assertEqual(repn.linear[id(m.y)], 1)
+        self.assertEqual(repn.multiplier, 1)
+        assertExpressionsEqual(self, repn.constant, 4 / m.x)
+        self.assertIsNone(repn.nonlinear)
+
+        e = m.z / m.x + m.y
+        cfg = VisitorConfig()
+        repn = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.x, m.z]).walk_expression(e)
+
+        self.assertEqual(len(repn.linear), 1)
+        self.assertIn(id(m.y), repn.linear)
+        self.assertEqual(repn.linear[id(m.y)], 1)
+        self.assertEqual(repn.multiplier, 1)
+        assertExpressionsEqual(self, repn.constant, m.z / m.x)
+        self.assertIsNone(repn.nonlinear)
+
+    def test_division_ANY_pseudo_constant(self):
+        m = self.make_model()
+        e = (m.x + 3 * m.z) / m.y
+
+        cfg = VisitorConfig()
+        repn = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.y]).walk_expression(e)
+
+        self.assertEqual(len(repn.linear), 2)
+        self.assertIn(id(m.x), repn.linear)
+        assertExpressionsEqual(self, repn.linear[id(m.x)], 1 / m.y)
+        self.assertIn(id(m.z), repn.linear)
+        assertExpressionsEqual(self, repn.linear[id(m.z)], (1 / m.y) * 3)
+        self.assertEqual(repn.multiplier, 1)
+        self.assertEqual(repn.constant, 0)
+        self.assertIsNone(repn.nonlinear)
+
+    def test_duplicate(self):
+        m = self.make_model()
+        e = (1 + m.x) ** 2 + m.y
+
+        cfg = VisitorConfig()
+        visitor = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.y])
+        visitor.max_exponential_expansion = 2
+        repn = visitor.walk_expression(e)
+
+        self.assertEqual(len(repn.linear), 0)
+        self.assertEqual(repn.multiplier, 1)
+        self.assertIs(repn.constant, m.y)
+        assertExpressionsEqual(self, repn.nonlinear, (m.x + 1) * (m.x + 1))
+
+    def test_pow_ANY_pseudo_constant(self):
+        m = self.make_model()
+        e = (m.x**2 + 3 * m.z) ** m.y
+
+        cfg = VisitorConfig()
+        repn = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.y]).walk_expression(e)
+
+        self.assertEqual(len(repn.linear), 0)
+        self.assertEqual(repn.multiplier, 1)
+        self.assertEqual(repn.constant, 0)
+        assertExpressionsEqual(self, repn.nonlinear, (m.x**2 + 3 * m.z) ** m.y)
+
+    def test_pow_pseudo_constant_ANY(self):
+        m = self.make_model()
+        e = m.y ** (m.x**2 + 3 * m.z)
+
+        cfg = VisitorConfig()
+        repn = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.y]).walk_expression(e)
+
+        self.assertEqual(len(repn.linear), 0)
+        self.assertEqual(repn.multiplier, 1)
+        self.assertEqual(repn.constant, 0)
+        assertExpressionsEqual(self, repn.nonlinear, m.y ** (m.x**2 + 3 * m.z))
+
+    def test_pow_linear_pseudo_constant(self):
+        m = self.make_model()
+        e = (m.x + 3 * m.z) ** m.y
+
+        cfg = VisitorConfig()
+        repn = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.y]).walk_expression(e)
+
+        self.assertEqual(len(repn.linear), 0)
+        self.assertEqual(repn.multiplier, 1)
+        self.assertEqual(repn.constant, 0)
+        assertExpressionsEqual(self, repn.nonlinear, (m.x + 3 * m.z) ** m.y)
+
+    def test_pow_pseudo_constant_linear(self):
+        m = self.make_model()
+        e = m.y ** (m.x + 3 * m.z)
+
+        cfg = VisitorConfig()
+        repn = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.y]).walk_expression(e)
+
+        self.assertEqual(len(repn.linear), 0)
+        self.assertEqual(repn.multiplier, 1)
+        self.assertEqual(repn.constant, 0)
+        assertExpressionsEqual(self, repn.nonlinear, m.y ** (m.x + 3 * m.z))
+
+    def test_0_mult(self):
+        m = self.make_model()
+        m.p = Var()
+        m.p.fix(0)
+        e = m.p * (m.y**2 + m.z)
+
+        cfg = VisitorConfig()
+        repn = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.z]).walk_expression(e)
+
+        self.assertEqual(len(repn.linear), 0)
+        self.assertEqual(repn.multiplier, 1)
+        self.assertIsNone(repn.nonlinear)
+        self.assertEqual(repn.constant, 0)
+
+    def test_0_mult_nan(self):
+        m = self.make_model()
+        m.p = Param(initialize=0, mutable=True)
+        m.y.domain = Any
+        m.y.fix(float('nan'))
+        e = m.p * (m.y**2 + m.x)
+
+        cfg = VisitorConfig()
+        repn = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.x]).walk_expression(e)
+
+        self.assertEqual(len(repn.linear), 0)
+        self.assertEqual(repn.multiplier, 1)
+        self.assertIsNone(repn.nonlinear)
+        self.assertIsInstance(repn.constant, InvalidNumber)
+        assertExpressionsEqual(self, repn.constant.value, 0 * (float('nan') + m.x))
+
+    def test_0_mult_nan_param(self):
+        m = self.make_model()
+        m.p = Param(initialize=0, mutable=True)
+        m.y.fix(float('nan'))
+        e = m.p * (m.y**2)
+
+        cfg = VisitorConfig()
+        repn = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.y]).walk_expression(e)
+
+        self.assertEqual(len(repn.linear), 0)
+        self.assertEqual(repn.multiplier, 1)
+        self.assertIsNone(repn.nonlinear)
+        self.assertIsInstance(repn.constant, InvalidNumber)
+        assertExpressionsEqual(self, repn.constant.value, 0 * float('nan'))
+
+    def test_0_mult_linear_with_nan(self):
+        m = self.make_model()
+        m.p = Param(initialize=0, mutable=True)
+        m.x.domain = Any
+        m.x.fix(float('nan'))
+        e = m.p * (3 * m.x * m.y + m.z)
+
+        cfg = VisitorConfig()
+        repn = ParameterizedLinearRepnVisitor(*cfg, wrt=[m.x]).walk_expression(e)
+
+        self.assertEqual(len(repn.linear), 2)
+        self.assertIn(id(m.y), repn.linear)
+        self.assertIsInstance(repn.linear[id(m.y)], InvalidNumber)
+        assertExpressionsEqual(self, repn.linear[id(m.y)].value, 0 * 3 * float('nan'))
+        self.assertIn(id(m.z), repn.linear)
+        self.assertEqual(repn.linear[id(m.z)], 0)
+        self.assertEqual(repn.multiplier, 1)
+        self.assertIsNone(repn.nonlinear)
+        self.assertEqual(repn.constant, 0)
diff --git a/pyomo/repn/tests/test_quadratic.py b/pyomo/repn/tests/test_quadratic.py
index 605c859464a..2d2e4022037 100644
--- a/pyomo/repn/tests/test_quadratic.py
+++ b/pyomo/repn/tests/test_quadratic.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/test_standard.py b/pyomo/repn/tests/test_standard.py
index b62d18e6eff..6c5a6e3e033 100644
--- a/pyomo/repn/tests/test_standard.py
+++ b/pyomo/repn/tests/test_standard.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/repn/tests/test_standard_form.py b/pyomo/repn/tests/test_standard_form.py
index d186f28dab8..4c66ae87c41 100644
--- a/pyomo/repn/tests/test_standard_form.py
+++ b/pyomo/repn/tests/test_standard_form.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -42,6 +42,23 @@ def test_linear_model(self):
         self.assertTrue(np.all(repn.c == np.array([0, 0, 0])))
         self.assertTrue(np.all(repn.A == np.array([[-1, -2, 0], [0, 1, 4]])))
         self.assertTrue(np.all(repn.rhs == np.array([-3, 5])))
+        self.assertEqual(repn.rows, [(m.c, -1), (m.d, 1)])
+        self.assertEqual(repn.columns, [m.x, m.y[1], m.y[3]])
+
+    def test_almost_dense_linear_model(self):
+        m = pyo.ConcreteModel()
+        m.x = pyo.Var()
+        m.y = pyo.Var([1, 2, 3])
+        m.c = pyo.Constraint(expr=m.x + 2 * m.y[1] + 4 * m.y[3] >= 10)
+        m.d = pyo.Constraint(expr=5 * m.x + 6 * m.y[1] + 8 * m.y[3] <= 20)
+
+        repn = LinearStandardFormCompiler().write(m)
+
+        self.assertTrue(np.all(repn.c == np.array([0, 0, 0])))
+        self.assertTrue(np.all(repn.A == np.array([[-1, -2, -4], [5, 6, 8]])))
+        self.assertTrue(np.all(repn.rhs == np.array([-10, 20])))
+        self.assertEqual(repn.rows, [(m.c, -1), (m.d, 1)])
+        self.assertEqual(repn.columns, [m.x, m.y[1], m.y[3]])
 
     def test_linear_model_row_col_order(self):
         m = pyo.ConcreteModel()
@@ -57,6 +74,8 @@ def test_linear_model_row_col_order(self):
         self.assertTrue(np.all(repn.c == np.array([0, 0, 0])))
         self.assertTrue(np.all(repn.A == np.array([[4, 0, 1], [0, -1, -2]])))
         self.assertTrue(np.all(repn.rhs == np.array([5, -3])))
+        self.assertEqual(repn.rows, [(m.d, 1), (m.c, -1)])
+        self.assertEqual(repn.columns, [m.y[3], m.x, m.y[1]])
 
     def test_suffix_warning(self):
         m = pyo.ConcreteModel()
@@ -222,6 +241,28 @@ def test_alternative_forms(self):
         )
         self._verify_solution(soln, repn, True)
 
+        repn = LinearStandardFormCompiler().write(
+            m, mixed_form=True, column_order=col_order
+        )
+
+        self.assertEqual(
+            repn.rows, [(m.c, -1), (m.d, 1), (m.e, 1), (m.e, -1), (m.f, 0)]
+        )
+        self.assertEqual(list(map(str, repn.x)), ['x', 'y[0]', 'y[1]', 'y[3]'])
+        self.assertEqual(
+            list(v.bounds for v in repn.x), [(None, None), (0, 10), (-5, 10), (-5, -2)]
+        )
+        ref = np.array(
+            [[1, 0, 2, 0], [0, 0, 1, 4], [0, 1, 6, 0], [0, 1, 6, 0], [1, 1, 0, 0]]
+        )
+        self.assertTrue(np.all(repn.A == ref))
+        self.assertTrue(np.all(repn.b == np.array([3, 5, 6, -3, 8])))
+        self.assertTrue(np.all(repn.c == np.array([[-1, 0, -5, 0], [1, 0, 0, 15]])))
+        # Note that the mixed_form solution is a mix of inequality and
+        # equality constraints, so we cannot (easily) reuse the
+        # _verify_solutions helper (as in the above cases):
+        # self._verify_solution(soln, repn, False)
+
         repn = LinearStandardFormCompiler().write(
             m, slack_form=True, nonnegative_vars=True, column_order=col_order
         )
diff --git a/pyomo/repn/tests/test_util.py b/pyomo/repn/tests/test_util.py
index 47cc6b1a63a..e0fea0fb45c 100644
--- a/pyomo/repn/tests/test_util.py
+++ b/pyomo/repn/tests/test_util.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -19,6 +19,7 @@
 from pyomo.common.errors import DeveloperError, InvalidValueError
 from pyomo.common.log import LoggingIntercept
 from pyomo.core.expr import (
+    NumericExpression,
     ProductExpression,
     NPV_ProductExpression,
     SumExpression,
@@ -671,16 +672,6 @@ def test_ExitNodeDispatcher_registration(self):
         self.assertEqual(len(end), 4)
         self.assertIn(NPV_ProductExpression, end)
 
-        class NewProductExpression(ProductExpression):
-            pass
-
-        node = NewProductExpression((6, 7))
-        with self.assertRaisesRegex(
-            DeveloperError, r".*Unexpected expression node type 'NewProductExpression'"
-        ):
-            end[node.__class__](None, node, *node.args)
-        self.assertEqual(len(end), 4)
-
         end[SumExpression, 2] = lambda v, n, *d: 2 * sum(d)
         self.assertEqual(len(end), 5)
 
@@ -708,8 +699,34 @@ class NewProductExpression(ProductExpression):
 
         self.assertEqual(end[node.__class__, 3, 4, 5, 6](None, node, *node.args), 6)
         self.assertEqual(len(end), 7)
+        # We don't cache etypes with more than 3 arguments
         self.assertNotIn((SumExpression, 3, 4, 5, 6), end)
 
+        class NewProductExpression(ProductExpression):
+            pass
+
+        node = NewProductExpression((6, 7))
+        self.assertEqual(end[node.__class__](None, node, *node.args), 42)
+        self.assertEqual(len(end), 8)
+        self.assertIn(NewProductExpression, end)
+
+        class UnknownExpression(NumericExpression):
+            pass
+
+        node = UnknownExpression((6, 7))
+        with self.assertRaisesRegex(
+            DeveloperError, r".*Unexpected expression node type 'UnknownExpression'"
+        ):
+            end[node.__class__](None, node, *node.args)
+        self.assertEqual(len(end), 8)
+
+        node = UnknownExpression((6, 7))
+        with self.assertRaisesRegex(
+            DeveloperError, r".*Unexpected expression node type 'UnknownExpression'"
+        ):
+            end[node.__class__, 6, 7](None, node, *node.args)
+        self.assertEqual(len(end), 8)
+
     def test_BeforeChildDispatcher_registration(self):
         class BeforeChildDispatcherTester(BeforeChildDispatcher):
             @staticmethod
@@ -734,15 +751,14 @@ def evaluate(self, node):
 
         node = 5
         self.assertEqual(bcd[node.__class__](None, node), (False, (_CONSTANT, 5)))
-        self.assertIs(bcd[int], bcd._before_native)
+        self.assertIs(bcd[int], bcd._before_native_numeric)
         self.assertEqual(len(bcd), 1)
 
         node = 'string'
         ans = bcd[node.__class__](None, node)
         self.assertEqual(ans, (False, (_CONSTANT, InvalidNumber(node))))
         self.assertEqual(
-            ''.join(ans[1][1].causes),
-            "'string' (<class 'str'>) is not a valid numeric type",
+            ''.join(ans[1][1].causes), "'string' (str) is not a valid numeric type"
         )
         self.assertIs(bcd[str], bcd._before_string)
         self.assertEqual(len(bcd), 2)
@@ -751,10 +767,9 @@ def evaluate(self, node):
         ans = bcd[node.__class__](None, node)
         self.assertEqual(ans, (False, (_CONSTANT, InvalidNumber(node))))
         self.assertEqual(
-            ''.join(ans[1][1].causes),
-            "True (<class 'bool'>) is not a valid numeric type",
+            ''.join(ans[1][1].causes), "True (bool) is not a valid numeric type"
         )
-        self.assertIs(bcd[bool], bcd._before_invalid)
+        self.assertIs(bcd[bool], bcd._before_native_logical)
         self.assertEqual(len(bcd), 3)
 
         node = 1j
@@ -771,14 +786,14 @@ class new_int(int):
 
         node = new_int(5)
         self.assertEqual(bcd[node.__class__](None, node), (False, (_CONSTANT, 5)))
-        self.assertIs(bcd[new_int], bcd._before_native)
+        self.assertIs(bcd[new_int], bcd._before_native_numeric)
         self.assertEqual(len(bcd), 5)
 
         node = []
         ans = bcd[node.__class__](None, node)
         self.assertEqual(ans, (False, (_CONSTANT, InvalidNumber([]))))
         self.assertEqual(
-            ''.join(ans[1][1].causes), "[] (<class 'list'>) is not a valid numeric type"
+            ''.join(ans[1][1].causes), "[] (list) is not a valid numeric type"
         )
         self.assertIs(bcd[list], bcd._before_invalid)
         self.assertEqual(len(bcd), 6)
diff --git a/pyomo/repn/util.py b/pyomo/repn/util.py
index b65aa9427d5..32ec99dac0f 100644
--- a/pyomo/repn/util.py
+++ b/pyomo/repn/util.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -25,6 +25,7 @@
     native_types,
     native_numeric_types,
     native_complex_types,
+    native_logical_types,
 )
 from pyomo.core.pyomoobject import PyomoObject
 from pyomo.core.base import (
@@ -39,7 +40,7 @@
     SortComponents,
 )
 from pyomo.core.base.component import ActiveComponent
-from pyomo.core.base.expression import _ExpressionData
+from pyomo.core.base.expression import NamedExpressionData
 from pyomo.core.expr.numvalue import is_fixed, value
 import pyomo.core.expr as EXPR
 import pyomo.core.kernel as kernel
@@ -54,7 +55,7 @@
     EXPR.NPV_SumExpression,
 }
 _named_subexpression_types = (
-    _ExpressionData,
+    NamedExpressionData,
     kernel.expression.expression,
     kernel.objective.objective,
 )
@@ -66,6 +67,7 @@
 
 class ExprType(enum.IntEnum):
     CONSTANT = 0
+    FIXED = 5
     MONOMIAL = 10
     LINEAR = 20
     QUADRATIC = 30
@@ -265,7 +267,9 @@ def __missing__(self, key):
     def register_dispatcher(self, visitor, child):
         child_type = type(child)
         if child_type in native_numeric_types:
-            self[child_type] = self._before_native
+            self[child_type] = self._before_native_numeric
+        elif child_type in native_logical_types:
+            self[child_type] = self._before_native_logical
         elif issubclass(child_type, str):
             self[child_type] = self._before_string
         elif child_type in native_types:
@@ -275,7 +279,7 @@ def register_dispatcher(self, visitor, child):
                 self[child_type] = self._before_invalid
         elif not hasattr(child, 'is_expression_type'):
             if check_if_numeric_type(child):
-                self[child_type] = self._before_native
+                self[child_type] = self._before_native_numeric
             else:
                 self[child_type] = self._before_invalid
         elif not child.is_expression_type():
@@ -306,9 +310,18 @@ def _before_general_expression(visitor, child):
         return True, None
 
     @staticmethod
-    def _before_native(visitor, child):
+    def _before_native_numeric(visitor, child):
         return False, (_CONSTANT, child)
 
+    @staticmethod
+    def _before_native_logical(visitor, child):
+        return False, (
+            _CONSTANT,
+            InvalidNumber(
+                child, f"{child!r} ({type(child).__name__}) is not a valid numeric type"
+            ),
+        )
+
     @staticmethod
     def _before_complex(visitor, child):
         return False, (_CONSTANT, complex_number_error(child, visitor, child))
@@ -318,7 +331,7 @@ def _before_invalid(visitor, child):
         return False, (
             _CONSTANT,
             InvalidNumber(
-                child, f"{child!r} ({type(child)}) is not a valid numeric type"
+                child, f"{child!r} ({type(child).__name__}) is not a valid numeric type"
             ),
         )
 
@@ -327,7 +340,7 @@ def _before_string(visitor, child):
         return False, (
             _CONSTANT,
             InvalidNumber(
-                child, f"{child!r} ({type(child)}) is not a valid numeric type"
+                child, f"{child!r} ({type(child).__name__}) is not a valid numeric type"
             ),
         )
 
@@ -366,18 +379,16 @@ class ExitNodeDispatcher(collections.defaultdict):
     `exitNode` callback
 
     This dispatcher implements a specialization of :py:`defaultdict`
-    that supports automatic type registration.  Any missing types will
-    return the :py:meth:`register_dispatcher` method, which (when called
-    as a callback) will interrogate the type, identify the appropriate
-    callback, add the callback to the dict, and return the result of
-    calling the callback.  As the callback is added to the dict, no type
-    will incur the overhead of `register_dispatcher` more than once.
+    that supports automatic type registration.  As the identified
+    callback is added to the dict, no type will incur the overhead of
+    `register_dispatcher` more than once.
 
     Note that in this case, the client is expected to register all
     non-NPV expression types.  The auto-registration is designed to only
     handle two cases:
     - Auto-detection of user-defined Named Expression types
     - Automatic mappimg of NPV expressions to their equivalent non-NPV handlers
+    - Automatic registration of derived expression types
 
     """
 
@@ -387,42 +398,56 @@ def __init__(self, *args, **kwargs):
         super().__init__(None, *args, **kwargs)
 
     def __missing__(self, key):
-        return functools.partial(self.register_dispatcher, key=key)
-
-    def register_dispatcher(self, visitor, node, *data, key=None):
+        if type(key) is tuple:
+            # Only lookup/cache argument-specific handlers for unary,
+            # binary and ternary operators
+            if len(key) <= 3:
+                node_class = key[0]
+                node_args = key[1:]
+            else:
+                node_class = key = key[0]
+                if node_class in self:
+                    return self[node_class]
+        else:
+            node_class = key
+        bases = node_class.__mro__
+        # Note: if we add an `etype`, then this special-case can be removed
         if (
-            isinstance(node, _named_subexpression_types)
-            or type(node) is kernel.expression.noclone
+            issubclass(node_class, _named_subexpression_types)
+            or node_class is kernel.expression.noclone
         ):
-            base_type = Expression
-        elif not node.is_potentially_variable():
-            base_type = node.potentially_variable_base_class()
-        else:
-            base_type = node.__class__
-        if isinstance(key, tuple):
-            base_key = (base_type,) + key[1:]
-            # Only cache handlers for unary, binary and ternary operators
-            cache = len(key) <= 4
-        else:
-            base_key = base_type
-            cache = True
-        if base_key in self:
-            fcn = self[base_key]
-        elif base_type in self:
-            fcn = self[base_type]
-        elif any((k[0] if k.__class__ is tuple else k) is base_type for k in self):
-            raise DeveloperError(
-                f"Base expression key '{base_key}' not found when inserting dispatcher"
-                f" for node '{type(node).__name__}' while walking expression tree."
-            )
-        else:
-            raise DeveloperError(
-                f"Unexpected expression node type '{type(node).__name__}' "
-                "found while walking expression tree."
+            bases = [Expression]
+        fcn = None
+        for base_type in bases:
+            if key is not node_class:
+                if (base_type,) + node_args in self:
+                    fcn = self[(base_type,) + node_args]
+                    break
+            if base_type in self:
+                fcn = self[base_type]
+                break
+        if fcn is None:
+            partial_matches = set(
+                k[0] for k in self if type(k) is tuple and issubclass(node_class, k[0])
             )
-        if cache:
-            self[key] = fcn
-        return fcn(visitor, node, *data)
+            for base_type in node_class.__mro__:
+                if node_class is not key:
+                    key = (base_type,) + node_args
+                if base_type in partial_matches:
+                    raise DeveloperError(
+                        f"Base expression key '{key}' not found when inserting "
+                        f"dispatcher for node '{node_class.__name__}' while walking "
+                        "expression tree."
+                    )
+            return self.unexpected_expression_type
+        self[key] = fcn
+        return fcn
+
+    def unexpected_expression_type(self, visitor, node, *args):
+        raise DeveloperError(
+            f"Unexpected expression node type '{type(node).__name__}' "
+            f"found while walking expression tree in {type(visitor).__name__}."
+        )
 
 
 def apply_node_operation(node, args):
@@ -469,7 +494,7 @@ def categorize_valid_components(
 
     Parameters
     ----------
-    model: _BlockData
+    model: BlockData
         The model tree to walk
 
     active: True or None
@@ -490,7 +515,7 @@ def categorize_valid_components(
 
     Returns
     -------
-    component_map: Dict[type, List[_BlockData]]
+    component_map: Dict[type, List[BlockData]]
         A dict mapping component type to a list of block data
         objects that contain declared component of that type.
 
diff --git a/pyomo/scripting/__init__.py b/pyomo/scripting/__init__.py
index a3c2c1bb7ce..7cb5ac652fc 100644
--- a/pyomo/scripting/__init__.py
+++ b/pyomo/scripting/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/scripting/commands.py b/pyomo/scripting/commands.py
index 7782962c2c1..ef59d64b542 100644
--- a/pyomo/scripting/commands.py
+++ b/pyomo/scripting/commands.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/scripting/convert.py b/pyomo/scripting/convert.py
index 2f0c0e5b400..20f9ef6d382 100644
--- a/pyomo/scripting/convert.py
+++ b/pyomo/scripting/convert.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,8 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['pyomo2lp', 'pyomo2nl', 'pyomo2dakota']
-
 import os
 import sys
 
diff --git a/pyomo/scripting/driver_help.py b/pyomo/scripting/driver_help.py
index 81970a6b5cc..38d1a4c16bf 100644
--- a/pyomo/scripting/driver_help.py
+++ b/pyomo/scripting/driver_help.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/scripting/interface.py b/pyomo/scripting/interface.py
index efb97470e43..fca485b279b 100644
--- a/pyomo/scripting/interface.py
+++ b/pyomo/scripting/interface.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/scripting/plugins/__init__.py b/pyomo/scripting/plugins/__init__.py
index 44e3956f314..86a3100e077 100644
--- a/pyomo/scripting/plugins/__init__.py
+++ b/pyomo/scripting/plugins/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/scripting/plugins/build_ext.py b/pyomo/scripting/plugins/build_ext.py
index 9ae63cbb8a1..5b4ac836a00 100644
--- a/pyomo/scripting/plugins/build_ext.py
+++ b/pyomo/scripting/plugins/build_ext.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/scripting/plugins/convert.py b/pyomo/scripting/plugins/convert.py
index 55290ed90ce..ea6742cec56 100644
--- a/pyomo/scripting/plugins/convert.py
+++ b/pyomo/scripting/plugins/convert.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/scripting/plugins/download.py b/pyomo/scripting/plugins/download.py
index 73a164ee708..afe56988009 100644
--- a/pyomo/scripting/plugins/download.py
+++ b/pyomo/scripting/plugins/download.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -38,9 +38,9 @@ def _call_impl(self, args, unparsed, logger):
         self.downloader.cacert = args.cacert
         self.downloader.insecure = args.insecure
         logger.info(
-            "As of February 9, 2023, AMPL GSL can no longer be downloaded\
-                    through download-extensions. Visit https://portal.ampl.com/\
-                    to download the AMPL GSL binaries."
+            "As of February 9, 2023, AMPL GSL can no longer be downloaded \
+            through download-extensions. Visit https://portal.ampl.com/ \
+            to download the AMPL GSL binaries."
         )
         for target in DownloadFactory:
             try:
diff --git a/pyomo/scripting/plugins/extras.py b/pyomo/scripting/plugins/extras.py
index 4cf9e623212..2bd1c4a0803 100644
--- a/pyomo/scripting/plugins/extras.py
+++ b/pyomo/scripting/plugins/extras.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/scripting/plugins/solve.py b/pyomo/scripting/plugins/solve.py
index 69451a04e3c..b2a849e995b 100644
--- a/pyomo/scripting/plugins/solve.py
+++ b/pyomo/scripting/plugins/solve.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/scripting/pyomo_command.py b/pyomo/scripting/pyomo_command.py
index b652e95372a..8beec41a8b1 100644
--- a/pyomo/scripting/pyomo_command.py
+++ b/pyomo/scripting/pyomo_command.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/scripting/pyomo_main.py b/pyomo/scripting/pyomo_main.py
index 9acafea0471..6497206fdda 100644
--- a/pyomo/scripting/pyomo_main.py
+++ b/pyomo/scripting/pyomo_main.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/scripting/pyomo_parser.py b/pyomo/scripting/pyomo_parser.py
index 345d400a1aa..9294d46f85e 100644
--- a/pyomo/scripting/pyomo_parser.py
+++ b/pyomo/scripting/pyomo_parser.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,8 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['add_subparser', 'get_parser', 'subparsers']
-
 import argparse
 import sys
 
diff --git a/pyomo/scripting/solve_config.py b/pyomo/scripting/solve_config.py
index 3048431d443..7ce3505d045 100644
--- a/pyomo/scripting/solve_config.py
+++ b/pyomo/scripting/solve_config.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/scripting/tests/__init__.py b/pyomo/scripting/tests/__init__.py
index 88e18b19035..d9146f7eee4 100644
--- a/pyomo/scripting/tests/__init__.py
+++ b/pyomo/scripting/tests/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/scripting/tests/test_cmds.py b/pyomo/scripting/tests/test_cmds.py
index 960e0d4ada1..9a120c8c175 100644
--- a/pyomo/scripting/tests/test_cmds.py
+++ b/pyomo/scripting/tests/test_cmds.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/scripting/util.py b/pyomo/scripting/util.py
index 5bc65eb35ae..b2a30ebaecd 100644
--- a/pyomo/scripting/util.py
+++ b/pyomo/scripting/util.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/__init__.py b/pyomo/solvers/__init__.py
index d93cfd77b3c..a4a626013c4 100644
--- a/pyomo/solvers/__init__.py
+++ b/pyomo/solvers/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/amplfunc_merge.py b/pyomo/solvers/amplfunc_merge.py
new file mode 100644
index 00000000000..e49fd20e20f
--- /dev/null
+++ b/pyomo/solvers/amplfunc_merge.py
@@ -0,0 +1,32 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+
+def amplfunc_string_merge(amplfunc, pyomo_amplfunc):
+    """Merge two AMPLFUNC variable strings eliminating duplicate lines"""
+    # Assume that the strings amplfunc and pyomo_amplfunc don't contain duplicates
+    # Assume that the path separator is correct for the OS so we don't need to
+    # worry about comparing Unix and Windows paths.
+    amplfunc_lines = amplfunc.split("\n")
+    existing = set(amplfunc_lines)
+    for line in pyomo_amplfunc.split("\n"):
+        # Skip lines we already have
+        if line not in existing:
+            amplfunc_lines.append(line)
+    # Remove empty lines which could happen if one or both of the strings is
+    # empty or there are two new lines in a row for whatever reason.
+    amplfunc_lines = [s for s in amplfunc_lines if s != ""]
+    return "\n".join(amplfunc_lines)
+
+
+def amplfunc_merge(env):
+    """Merge AMPLFUNC and PYOMO_AMPLFUNC in an environment var dict"""
+    return amplfunc_string_merge(env.get("AMPLFUNC", ""), env.get("PYOMO_AMPLFUNC", ""))
diff --git a/pyomo/solvers/mockmip.py b/pyomo/solvers/mockmip.py
index 9497a6dff9d..2c28b7a9be0 100644
--- a/pyomo/solvers/mockmip.py
+++ b/pyomo/solvers/mockmip.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/plugins/__init__.py b/pyomo/solvers/plugins/__init__.py
index 797ed5036bd..2a7bf2fea04 100644
--- a/pyomo/solvers/plugins/__init__.py
+++ b/pyomo/solvers/plugins/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/plugins/converter/__init__.py b/pyomo/solvers/plugins/converter/__init__.py
index b6baf4f6682..56c32f1c8c1 100644
--- a/pyomo/solvers/plugins/converter/__init__.py
+++ b/pyomo/solvers/plugins/converter/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/plugins/converter/ampl.py b/pyomo/solvers/plugins/converter/ampl.py
index b718faf2d21..0798115a448 100644
--- a/pyomo/solvers/plugins/converter/ampl.py
+++ b/pyomo/solvers/plugins/converter/ampl.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/plugins/converter/glpsol.py b/pyomo/solvers/plugins/converter/glpsol.py
index a38892e3cf5..9b404567c4d 100644
--- a/pyomo/solvers/plugins/converter/glpsol.py
+++ b/pyomo/solvers/plugins/converter/glpsol.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/plugins/converter/model.py b/pyomo/solvers/plugins/converter/model.py
index 89a521d1521..817df157bf5 100644
--- a/pyomo/solvers/plugins/converter/model.py
+++ b/pyomo/solvers/plugins/converter/model.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/plugins/converter/pico.py b/pyomo/solvers/plugins/converter/pico.py
index 7fd0d11222b..e5d008da347 100644
--- a/pyomo/solvers/plugins/converter/pico.py
+++ b/pyomo/solvers/plugins/converter/pico.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/plugins/solvers/ASL.py b/pyomo/solvers/plugins/solvers/ASL.py
index debcd27f75e..7acd59936b1 100644
--- a/pyomo/solvers/plugins/solvers/ASL.py
+++ b/pyomo/solvers/plugins/solvers/ASL.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -23,6 +23,7 @@
 from pyomo.opt.solver import SystemCallSolver
 from pyomo.core.kernel.block import IBlock
 from pyomo.solvers.mockmip import MockMIP
+from pyomo.solvers.amplfunc_merge import amplfunc_merge
 from pyomo.core import TransformationFactory
 
 import logging
@@ -100,7 +101,8 @@ def _get_version(self):
                 timeout=5,
                 stdout=subprocess.PIPE,
                 stderr=subprocess.STDOUT,
-                universal_newlines=True,
+                text=True,
+                errors='ignore',
             )
             ver = _extract_version(results.stdout)
             if ver is None:
@@ -158,11 +160,9 @@ def create_command_line(self, executable, problem_files):
         # Pyomo/Pyomo) with any user-specified external function
         # libraries
         #
-        if 'PYOMO_AMPLFUNC' in env:
-            if 'AMPLFUNC' in env:
-                env['AMPLFUNC'] += "\n" + env['PYOMO_AMPLFUNC']
-            else:
-                env['AMPLFUNC'] = env['PYOMO_AMPLFUNC']
+        amplfunc = amplfunc_merge(env)
+        if amplfunc:
+            env['AMPLFUNC'] = amplfunc
 
         cmd = [executable, problem_files[0], '-AMPL']
         if self._timer:
diff --git a/pyomo/solvers/plugins/solvers/BARON.py b/pyomo/solvers/plugins/solvers/BARON.py
index eb5ac0830c5..044cab27b86 100644
--- a/pyomo/solvers/plugins/solvers/BARON.py
+++ b/pyomo/solvers/plugins/solvers/BARON.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/plugins/solvers/CBCplugin.py b/pyomo/solvers/plugins/solvers/CBCplugin.py
index 86871dbc1ac..20876b07331 100644
--- a/pyomo/solvers/plugins/solvers/CBCplugin.py
+++ b/pyomo/solvers/plugins/solvers/CBCplugin.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,8 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['CBC', 'MockCBC']
-
 import os
 import re
 import time
@@ -18,6 +16,7 @@
 import subprocess
 
 from pyomo.common import Executable
+from pyomo.common.enums import maximize, minimize
 from pyomo.common.errors import ApplicationError
 from pyomo.common.collections import Bunch
 from pyomo.common.tempfiles import TempfileManager
@@ -31,7 +30,6 @@
     SolverStatus,
     TerminationCondition,
     SolutionStatus,
-    ProblemSense,
     Solution,
 )
 from pyomo.opt.solver import SystemCallSolver
@@ -445,7 +443,7 @@ def process_logfile(self):
         #
         # Parse logfile lines
         #
-        results.problem.sense = ProblemSense.minimize
+        results.problem.sense = minimize
         results.problem.name = None
         optim_value = float('inf')
         lower_bound = None
@@ -457,7 +455,7 @@ def process_logfile(self):
             tokens = tuple(re.split('[ \t]+', line.strip()))
             n_tokens = len(tokens)
             if n_tokens > 1:
-                # https://projects.coin-or.org/Cbc/browser/trunk/Cbc/src/CbcSolver.cpp?rev=2497#L3769
+                # https://github.com/coin-or/Cbc/blob/cb6bf98/Cbc/src/CbcSolver.cpp#L3769
                 if n_tokens > 4 and tokens[:4] == (
                     'Continuous',
                     'objective',
@@ -541,7 +539,7 @@ def process_logfile(self):
                         results.problem.name = results.problem.name.split('/')[-1]
                     if '\\' in results.problem.name:
                         results.problem.name = results.problem.name.split('\\')[-1]
-                # https://projects.coin-or.org/Cbc/browser/trunk/Cbc/src/CbcSolver.cpp?rev=2497#L10840
+                # https://github.com/coin-or/Cbc/blob/cb6bf98/Cbc/src/CbcSolver.cpp#L10840
                 elif tokens[0] == 'Presolve':
                     if n_tokens > 9 and tokens[3] == 'rows,' and tokens[6] == 'columns':
                         results.problem.number_of_variables = int(tokens[4]) - int(
@@ -553,7 +551,7 @@ def process_logfile(self):
                         results.problem.number_of_objectives = 1
                     elif n_tokens > 6 and tokens[6] == 'infeasible':
                         soln.status = SolutionStatus.infeasible
-                # https://projects.coin-or.org/Cbc/browser/trunk/Cbc/src/CbcSolver.cpp?rev=2497#L11105
+                # https://github.com/coin-or/Cbc/blob/cb6bf98/Cbc/src/CbcSolver.cpp#L11105
                 elif (
                     n_tokens > 11
                     and tokens[:2] == ('Problem', 'has')
@@ -565,7 +563,7 @@ def process_logfile(self):
                     results.problem.number_of_constraints = int(tokens[2])
                     results.problem.number_of_nonzeros = int(tokens[6][1:])
                     results.problem.number_of_objectives = 1
-                # https://projects.coin-or.org/Cbc/browser/trunk/Cbc/src/CbcSolver.cpp?rev=2497#L10814
+                # https://github.com/coin-or/Cbc/blob/cb6bf98/Cbc/src/CbcSolver.cpp#L10814
                 elif (
                     n_tokens > 8
                     and tokens[:3] == ('Original', 'problem', 'has')
@@ -580,8 +578,8 @@ def process_logfile(self):
                     'CoinLpIO::readLp(): Maximization problem reformulated as minimization'
                     in ' '.join(tokens)
                 ):
-                    results.problem.sense = ProblemSense.maximize
-                # https://projects.coin-or.org/Cbc/browser/trunk/Cbc/src/CbcSolver.cpp?rev=2497#L3047
+                    results.problem.sense = maximize
+                # https://github.com/coin-or/Cbc/blob/cb6bf98/Cbc/src/CbcSolver.cpp#L3047
                 elif n_tokens > 3 and tokens[:2] == ('Result', '-'):
                     if tokens[2:4] in [('Run', 'abandoned'), ('User', 'ctrl-c')]:
                         results.solver.termination_condition = (
@@ -611,15 +609,15 @@ def process_logfile(self):
                                 'solution': TerminationCondition.other,
                                 'iterations': TerminationCondition.maxIterations,
                             }.get(tokens[4], TerminationCondition.other)
-                    # perhaps from https://projects.coin-or.org/Cbc/browser/trunk/Cbc/src/CbcSolver.cpp?rev=2497#L12318
+                    # https://github.com/coin-or/Cbc/blob/cb6bf98/Cbc/src/CbcSolver.cpp#L12318
                     elif n_tokens > 3 and tokens[2] == "Finished":
                         soln.status = SolutionStatus.optimal
                         optim_value = _float(tokens[4])
-                # https://projects.coin-or.org/Cbc/browser/trunk/Cbc/src/CbcSolver.cpp?rev=2497#L7904
+                # https://github.com/coin-or/Cbc/blob/cb6bf98/Cbc/src/CbcSolver.cpp#L7904
                 elif n_tokens >= 3 and tokens[:2] == ('Objective', 'value:'):
                     # parser for log file generetated with discrete variable
                     optim_value = _float(tokens[2])
-                # https://projects.coin-or.org/Cbc/browser/trunk/Cbc/src/CbcSolver.cpp?rev=2497#L7904
+                # https://github.com/coin-or/Cbc/blob/cb6bf98/Cbc/src/CbcSolver.cpp#L7904
                 elif n_tokens >= 4 and tokens[:4] == (
                     'No',
                     'feasible',
@@ -632,25 +630,25 @@ def process_logfile(self):
                         lower_bound is None
                     ):  # Only use if not already found since this is to less decimal places
                         results.problem.lower_bound = _float(tokens[2])
-                # https://projects.coin-or.org/Cbc/browser/trunk/Cbc/src/CbcSolver.cpp?rev=2497#L7918
+                # https://github.com/coin-or/Cbc/blob/cb6bf98/Cbc/src/CbcSolver.cpp#L7918
                 elif tokens[0] == 'Gap:':
                     # This is relative and only to 2 decimal places - could calculate explicitly using lower bound
                     gap = _float(tokens[1])
-                # https://projects.coin-or.org/Cbc/browser/trunk/Cbc/src/CbcSolver.cpp?rev=2497#L7923
+                # https://github.com/coin-or/Cbc/blob/cb6bf98/Cbc/src/CbcSolver.cpp#L7923
                 elif n_tokens > 2 and tokens[:2] == ('Enumerated', 'nodes:'):
                     nodes = int(tokens[2])
-                # https://projects.coin-or.org/Cbc/browser/trunk/Cbc/src/CbcSolver.cpp?rev=2497#L7926
+                # https://github.com/coin-or/Cbc/blob/cb6bf98/Cbc/src/CbcSolver.cpp#L7926
                 elif n_tokens > 2 and tokens[:2] == ('Total', 'iterations:'):
                     results.solver.statistics.black_box.number_of_iterations = int(
                         tokens[2]
                     )
-                # https://projects.coin-or.org/Cbc/browser/trunk/Cbc/src/CbcSolver.cpp?rev=2497#L7930
+                # https://github.com/coin-or/Cbc/blob/cb6bf98/Cbc/src/CbcSolver.cpp#L7930
                 elif n_tokens > 3 and tokens[:3] == ('Time', '(CPU', 'seconds):'):
                     results.solver.system_time = _float(tokens[3])
-                # https://projects.coin-or.org/Cbc/browser/trunk/Cbc/src/CbcSolver.cpp?rev=2497#L7933
+                # https://github.com/coin-or/Cbc/blob/cb6bf98/Cbc/src/CbcSolver.cpp#L7933
                 elif n_tokens > 3 and tokens[:3] == ('Time', '(Wallclock', 'Seconds):'):
                     results.solver.wallclock_time = _float(tokens[3])
-                # https://projects.coin-or.org/Cbc/browser/trunk/Cbc/src/CbcSolver.cpp?rev=2497#L10477
+                # https://github.com/coin-or/Cbc/blob/cb6bf98/Cbc/src/CbcSolver.cpp#L10477
                 elif n_tokens > 4 and tokens[:4] == (
                     'Total',
                     'time',
@@ -754,9 +752,9 @@ def process_logfile(self):
                     "maxIterations parameter."
                 )
         soln.gap = gap
-        if results.problem.sense == ProblemSense.minimize:
+        if results.problem.sense == minimize:
             upper_bound = optim_value
-        elif results.problem.sense == ProblemSense.maximize:
+        elif results.problem.sense == maximize:
             _ver = self.version()
             if _ver and _ver[:3] < (2, 10, 2):
                 optim_value *= -1
@@ -826,7 +824,7 @@ def process_soln_file(self, results):
             INPUT = []
 
         _ver = self.version()
-        invert_objective_sense = results.problem.sense == ProblemSense.maximize and (
+        invert_objective_sense = results.problem.sense == maximize and (
             _ver and _ver[:3] < (2, 10, 2)
         )
 
@@ -834,11 +832,15 @@ def process_soln_file(self, results):
             tokens = tuple(re.split('[ \t]+', line.strip()))
             n_tokens = len(tokens)
             #
-            # These are the only header entries CBC will generate (identified via browsing CbcSolver.cpp)
-            # See https://projects.coin-or.org/Cbc/browser/trunk/Cbc/src/CbcSolver.cpp
-            # Search for (no integer solution - continuous used)      Currently line 9912 as of rev2497
-            # Note that since this possibly also covers old CBC versions, we shall not be removing any functionality,
-            # even if it is not seen in the current revision
+            # These are the only header entries CBC will generate
+            # (identified via browsing CbcSolver.cpp).  See
+            #     https://github.com/coin-or/Cbc/tree/master/src/CbcSolver.cpp
+            # Search for "(no integer solution - continuous used)"
+            # (L10796 as of cb855c7)
+            #
+            # Note that since this possibly also supports old CBC
+            # versions, we shall not be removing any functionality, even
+            # if it is not seen in the current revision
             #
             if not header_processed:
                 if tokens[0] == 'Optimal':
diff --git a/pyomo/solvers/plugins/solvers/CONOPT.py b/pyomo/solvers/plugins/solvers/CONOPT.py
index 30e8ada11a1..3455eede67b 100644
--- a/pyomo/solvers/plugins/solvers/CONOPT.py
+++ b/pyomo/solvers/plugins/solvers/CONOPT.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -79,7 +79,7 @@ def _get_version(self):
             return _extract_version('')
         results = subprocess.run(
             [solver_exec],
-            timeout=1,
+            timeout=self._version_timeout,
             stdout=subprocess.PIPE,
             stderr=subprocess.STDOUT,
             universal_newlines=True,
diff --git a/pyomo/solvers/plugins/solvers/CPLEX.py b/pyomo/solvers/plugins/solvers/CPLEX.py
index 9755bc58614..3a08257c87c 100644
--- a/pyomo/solvers/plugins/solvers/CPLEX.py
+++ b/pyomo/solvers/plugins/solvers/CPLEX.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -17,6 +17,7 @@
 import subprocess
 
 from pyomo.common import Executable
+from pyomo.common.enums import maximize, minimize
 from pyomo.common.errors import ApplicationError
 from pyomo.common.tempfiles import TempfileManager
 
@@ -28,7 +29,6 @@
     SolverStatus,
     TerminationCondition,
     SolutionStatus,
-    ProblemSense,
     Solution,
 )
 from pyomo.opt.solver import ILMLicensedSystemCallSolver
@@ -404,7 +404,7 @@ def _get_version(self):
             return _extract_version('')
         results = subprocess.run(
             [solver_exec, '-c', 'quit'],
-            timeout=1,
+            timeout=self._version_timeout,
             stdout=subprocess.PIPE,
             stderr=subprocess.STDOUT,
             universal_newlines=True,
@@ -547,9 +547,9 @@ def process_logfile(self):
                 ):  # CPLEX 11.2 and subsequent has two Nonzeros sections.
                     results.problem.number_of_nonzeros = int(tokens[2])
             elif len(tokens) >= 5 and tokens[4] == "MINIMIZE":
-                results.problem.sense = ProblemSense.minimize
+                results.problem.sense = minimize
             elif len(tokens) >= 5 and tokens[4] == "MAXIMIZE":
-                results.problem.sense = ProblemSense.maximize
+                results.problem.sense = maximize
             elif (
                 len(tokens) >= 4
                 and tokens[0] == "Solution"
@@ -859,9 +859,9 @@ def process_soln_file(self, results):
                     else:
                         sense = tokens[0].lower()
                         if sense in ['max', 'maximize']:
-                            results.problem.sense = ProblemSense.maximize
+                            results.problem.sense = maximize
                         if sense in ['min', 'minimize']:
-                            results.problem.sense = ProblemSense.minimize
+                            results.problem.sense = minimize
                     break
                 tINPUT.close()
 
@@ -952,7 +952,7 @@ def process_soln_file(self, results):
                 )
                 if primal_feasible == 1:
                     soln.status = SolutionStatus.feasible
-                    if results.problem.sense == ProblemSense.minimize:
+                    if results.problem.sense == minimize:
                         results.problem.upper_bound = soln.objective[
                             '__default_objective__'
                         ]['Value']
@@ -964,7 +964,7 @@ def process_soln_file(self, results):
                     soln.status = SolutionStatus.infeasible
 
         if self._best_bound is not None:
-            if results.problem.sense == ProblemSense.minimize:
+            if results.problem.sense == minimize:
                 results.problem.lower_bound = self._best_bound
             else:
                 results.problem.upper_bound = self._best_bound
diff --git a/pyomo/solvers/plugins/solvers/GAMS.py b/pyomo/solvers/plugins/solvers/GAMS.py
index d0365d49078..035bd0b7603 100644
--- a/pyomo/solvers/plugins/solvers/GAMS.py
+++ b/pyomo/solvers/plugins/solvers/GAMS.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -36,12 +36,11 @@
     Solution,
     SolutionStatus,
     TerminationCondition,
-    ProblemSense,
 )
 
 from pyomo.common.dependencies import attempt_import
 
-gdxcc, gdxcc_available = attempt_import('gdxcc', defer_check=True)
+gdxcc, gdxcc_available = attempt_import('gdxcc')
 
 logger = logging.getLogger('pyomo.solvers')
 
@@ -198,8 +197,8 @@ def _get_version(self):
             return _extract_version('')
         from gams import GamsWorkspace
 
-        ws = GamsWorkspace()
-        version = tuple(int(i) for i in ws._version.split('.')[:4])
+        workspace = GamsWorkspace()
+        version = tuple(int(i) for i in workspace._version.split('.')[:4])
         while len(version) < 4:
             version += (0,)
         return version
@@ -209,8 +208,8 @@ def _run_simple_model(self, n):
         try:
             from gams import GamsWorkspace, DebugLevel
 
-            ws = GamsWorkspace(debug=DebugLevel.Off, working_directory=tmpdir)
-            t1 = ws.add_job_from_string(self._simple_model(n))
+            workspace = GamsWorkspace(debug=DebugLevel.Off, working_directory=tmpdir)
+            t1 = workspace.add_job_from_string(self._simple_model(n))
             t1.run()
             return True
         except:
@@ -330,12 +329,12 @@ def solve(self, *args, **kwds):
         if tmpdir is not None and os.path.exists(tmpdir):
             newdir = False
 
-        ws = GamsWorkspace(
+        workspace = GamsWorkspace(
             debug=DebugLevel.KeepFiles if keepfiles else DebugLevel.Off,
             working_directory=tmpdir,
         )
 
-        t1 = ws.add_job_from_string(output_file.getvalue())
+        t1 = workspace.add_job_from_string(output_file.getvalue())
 
         try:
             with OutputStream(tee=tee, logfile=logfile) as output_stream:
@@ -349,7 +348,9 @@ def solve(self, *args, **kwds):
                 # Always name working directory or delete files,
                 # regardless of any errors.
                 if keepfiles:
-                    print("\nGAMS WORKING DIRECTORY: %s\n" % ws.working_directory)
+                    print(
+                        "\nGAMS WORKING DIRECTORY: %s\n" % workspace.working_directory
+                    )
                 elif tmpdir is not None:
                     # Garbage collect all references to t1.out_db
                     # So that .gdx file can be deleted
@@ -359,7 +360,7 @@ def solve(self, *args, **kwds):
         except:
             # Catch other errors and remove files first
             if keepfiles:
-                print("\nGAMS WORKING DIRECTORY: %s\n" % ws.working_directory)
+                print("\nGAMS WORKING DIRECTORY: %s\n" % workspace.working_directory)
             elif tmpdir is not None:
                 # Garbage collect all references to t1.out_db
                 # So that .gdx file can be deleted
@@ -398,7 +399,9 @@ def solve(self, *args, **kwds):
         extract_rc = 'rc' in model_suffixes
 
         results = SolverResults()
-        results.problem.name = os.path.join(ws.working_directory, t1.name + '.gms')
+        results.problem.name = os.path.join(
+            workspace.working_directory, t1.name + '.gms'
+        )
         results.problem.lower_bound = t1.out_db["OBJEST"].find_record().value
         results.problem.upper_bound = t1.out_db["OBJEST"].find_record().value
         results.problem.number_of_variables = t1.out_db["NUMVAR"].find_record().value
@@ -418,11 +421,10 @@ def solve(self, *args, **kwds):
         assert len(obj) == 1, 'Only one objective is allowed.'
         obj = obj[0]
         objctvval = t1.out_db["OBJVAL"].find_record().value
+        results.problem.sense = obj.sense
         if obj.is_minimizing():
-            results.problem.sense = ProblemSense.minimize
             results.problem.upper_bound = objctvval
         else:
-            results.problem.sense = ProblemSense.maximize
             results.problem.lower_bound = objctvval
 
         results.solver.name = "GAMS " + str(self.version())
@@ -587,7 +589,7 @@ def solve(self, *args, **kwds):
         results.solution.insert(soln)
 
         if keepfiles:
-            print("\nGAMS WORKING DIRECTORY: %s\n" % ws.working_directory)
+            print("\nGAMS WORKING DIRECTORY: %s\n" % workspace.working_directory)
         elif tmpdir is not None:
             # Garbage collect all references to t1.out_db
             # So that .gdx file can be deleted
@@ -980,11 +982,10 @@ def solve(self, *args, **kwds):
         assert len(obj) == 1, 'Only one objective is allowed.'
         obj = obj[0]
         objctvval = stat_vars["OBJVAL"]
+        results.problem.sense = obj.sense
         if obj.is_minimizing():
-            results.problem.sense = ProblemSense.minimize
             results.problem.upper_bound = objctvval
         else:
-            results.problem.sense = ProblemSense.maximize
             results.problem.lower_bound = objctvval
 
         results.solver.name = "GAMS " + str(self.version())
diff --git a/pyomo/solvers/plugins/solvers/GLPK.py b/pyomo/solvers/plugins/solvers/GLPK.py
index a5b8ad9c019..c8d5bc14237 100644
--- a/pyomo/solvers/plugins/solvers/GLPK.py
+++ b/pyomo/solvers/plugins/solvers/GLPK.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -19,6 +19,8 @@
 
 from pyomo.common import Executable
 from pyomo.common.collections import Bunch
+from pyomo.common.enums import maximize, minimize
+from pyomo.common.errors import ApplicationError
 from pyomo.opt import (
     SolverFactory,
     OptSolver,
@@ -27,7 +29,6 @@
     SolverResults,
     TerminationCondition,
     SolutionStatus,
-    ProblemSense,
 )
 from pyomo.opt.base.solvers import _extract_version
 from pyomo.opt.solver import SystemCallSolver
@@ -137,7 +138,7 @@ def _get_version(self, executable=None):
             [executable, "--version"],
             stdout=subprocess.PIPE,
             stderr=subprocess.STDOUT,
-            timeout=1,
+            timeout=self._version_timeout,
             universal_newlines=True,
         )
         return _extract_version(result.stdout)
@@ -307,10 +308,8 @@ def process_soln_file(self, results):
             ):
                 raise ValueError
 
-            self.is_integer = 'mip' == ptype and True or False
-            prob.sense = (
-                'min' == psense and ProblemSense.minimize or ProblemSense.maximize
-            )
+            self.is_integer = 'mip' == ptype
+            prob.sense = minimize if 'min' == psense else maximize
             prob.number_of_constraints = prows
             prob.number_of_nonzeros = pnonz
             prob.number_of_variables = pcols
diff --git a/pyomo/solvers/plugins/solvers/GUROBI.py b/pyomo/solvers/plugins/solvers/GUROBI.py
index e0eddf008af..3a3a4d52322 100644
--- a/pyomo/solvers/plugins/solvers/GUROBI.py
+++ b/pyomo/solvers/plugins/solvers/GUROBI.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -18,6 +18,7 @@
 
 from pyomo.common import Executable
 from pyomo.common.collections import Bunch
+from pyomo.common.enums import maximize, minimize
 from pyomo.common.fileutils import this_file_dir
 from pyomo.common.tee import capture_output
 from pyomo.common.tempfiles import TempfileManager
@@ -28,7 +29,6 @@
     SolverStatus,
     TerminationCondition,
     SolutionStatus,
-    ProblemSense,
     Solution,
 )
 from pyomo.opt.solver import ILMLicensedSystemCallSolver
@@ -472,7 +472,7 @@ def process_soln_file(self, results):
                             soln.objective['__default_objective__'] = {
                                 'Value': float(tokens[1])
                             }
-                            if results.problem.sense == ProblemSense.minimize:
+                            if results.problem.sense == minimize:
                                 results.problem.upper_bound = float(tokens[1])
                             else:
                                 results.problem.lower_bound = float(tokens[1])
@@ -514,9 +514,9 @@ def process_soln_file(self, results):
                 elif section == 1:
                     if tokens[0] == 'sense':
                         if tokens[1] == 'minimize':
-                            results.problem.sense = ProblemSense.minimize
+                            results.problem.sense = minimize
                         elif tokens[1] == 'maximize':
-                            results.problem.sense = ProblemSense.maximize
+                            results.problem.sense = maximize
                     else:
                         try:
                             val = eval(tokens[1])
diff --git a/pyomo/solvers/plugins/solvers/GUROBI_RUN.py b/pyomo/solvers/plugins/solvers/GUROBI_RUN.py
index 2b505adf49c..88f953e18ae 100644
--- a/pyomo/solvers/plugins/solvers/GUROBI_RUN.py
+++ b/pyomo/solvers/plugins/solvers/GUROBI_RUN.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/plugins/solvers/IPOPT.py b/pyomo/solvers/plugins/solvers/IPOPT.py
index 611180113c8..21045cb7b4f 100644
--- a/pyomo/solvers/plugins/solvers/IPOPT.py
+++ b/pyomo/solvers/plugins/solvers/IPOPT.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -21,6 +21,8 @@
 from pyomo.opt.results import SolverStatus, SolverResults, TerminationCondition
 from pyomo.opt.solver import SystemCallSolver
 
+from pyomo.solvers.amplfunc_merge import amplfunc_merge
+
 import logging
 
 logger = logging.getLogger('pyomo.solvers')
@@ -79,7 +81,7 @@ def _get_version(self):
             return _extract_version('')
         results = subprocess.run(
             [solver_exec, "-v"],
-            timeout=1,
+            timeout=self._version_timeout,
             stdout=subprocess.PIPE,
             stderr=subprocess.STDOUT,
             universal_newlines=True,
@@ -119,11 +121,9 @@ def create_command_line(self, executable, problem_files):
         # Pyomo/Pyomo) with any user-specified external function
         # libraries
         #
-        if 'PYOMO_AMPLFUNC' in env:
-            if 'AMPLFUNC' in env:
-                env['AMPLFUNC'] += "\n" + env['PYOMO_AMPLFUNC']
-            else:
-                env['AMPLFUNC'] = env['PYOMO_AMPLFUNC']
+        amplfunc = amplfunc_merge(env)
+        if amplfunc:
+            env['AMPLFUNC'] = amplfunc
 
         cmd = [executable, problem_files[0], '-AMPL']
         if self._timer:
diff --git a/pyomo/solvers/plugins/solvers/SAS.py b/pyomo/solvers/plugins/solvers/SAS.py
new file mode 100644
index 00000000000..d7b09e29fde
--- /dev/null
+++ b/pyomo/solvers/plugins/solvers/SAS.py
@@ -0,0 +1,811 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import logging
+import sys
+from os import stat
+from abc import ABC, abstractmethod
+from io import StringIO
+
+from pyomo.opt.base import ProblemFormat, ResultsFormat, OptSolver
+from pyomo.opt.base.solvers import SolverFactory
+from pyomo.common.collections import Bunch
+from pyomo.common.dependencies import attempt_import
+from pyomo.opt.results import (
+    SolverResults,
+    SolverStatus,
+    TerminationCondition,
+    SolutionStatus,
+    ProblemSense,
+)
+from pyomo.common.tempfiles import TempfileManager
+from pyomo.core.base import Var
+from pyomo.core.base.block import BlockData
+from pyomo.core.kernel.block import IBlock
+from pyomo.common.log import LogStream
+from pyomo.common.tee import capture_output, TeeStream
+
+
+uuid, uuid_available = attempt_import('uuid')
+logger = logging.getLogger("pyomo.solvers")
+
+
+STATUS_TO_SOLVERSTATUS = {
+    "OK": SolverStatus.ok,
+    "SYNTAX_ERROR": SolverStatus.error,
+    "DATA_ERROR": SolverStatus.error,
+    "OUT_OF_MEMORY": SolverStatus.aborted,
+    "IO_ERROR": SolverStatus.error,
+    "ERROR": SolverStatus.error,
+}
+
+# This combines all status codes from OPTLP/solvelp and OPTMILP/solvemilp
+SOLSTATUS_TO_TERMINATIONCOND = {
+    "OPTIMAL": TerminationCondition.optimal,
+    "OPTIMAL_AGAP": TerminationCondition.optimal,
+    "OPTIMAL_RGAP": TerminationCondition.optimal,
+    "OPTIMAL_COND": TerminationCondition.optimal,
+    "TARGET": TerminationCondition.optimal,
+    "CONDITIONAL_OPTIMAL": TerminationCondition.optimal,
+    "FEASIBLE": TerminationCondition.feasible,
+    "INFEASIBLE": TerminationCondition.infeasible,
+    "UNBOUNDED": TerminationCondition.unbounded,
+    "INFEASIBLE_OR_UNBOUNDED": TerminationCondition.infeasibleOrUnbounded,
+    "SOLUTION_LIM": TerminationCondition.maxEvaluations,
+    "NODE_LIM_SOL": TerminationCondition.maxEvaluations,
+    "NODE_LIM_NOSOL": TerminationCondition.maxEvaluations,
+    "ITERATION_LIMIT_REACHED": TerminationCondition.maxIterations,
+    "TIME_LIM_SOL": TerminationCondition.maxTimeLimit,
+    "TIME_LIM_NOSOL": TerminationCondition.maxTimeLimit,
+    "TIME_LIMIT_REACHED": TerminationCondition.maxTimeLimit,
+    "ABORTED": TerminationCondition.userInterrupt,
+    "ABORT_SOL": TerminationCondition.userInterrupt,
+    "ABORT_NOSOL": TerminationCondition.userInterrupt,
+    "OUTMEM_SOL": TerminationCondition.solverFailure,
+    "OUTMEM_NOSOL": TerminationCondition.solverFailure,
+    "FAILED": TerminationCondition.solverFailure,
+    "FAIL_SOL": TerminationCondition.solverFailure,
+    "FAIL_NOSOL": TerminationCondition.solverFailure,
+}
+
+
+SOLSTATUS_TO_MESSAGE = {
+    "OPTIMAL": "The solution is optimal.",
+    "OPTIMAL_AGAP": "The solution is optimal within the absolute gap specified by the ABSOBJGAP= option.",
+    "OPTIMAL_RGAP": "The solution is optimal within the relative gap specified by the RELOBJGAP= option.",
+    "OPTIMAL_COND": "The solution is optimal, but some infeasibilities (primal, bound, or integer) exceed tolerances due to scaling or choice of a small INTTOL= value.",
+    "TARGET": "The solution is not worse than the target specified by the TARGET= option.",
+    "CONDITIONAL_OPTIMAL": "The solution is optimal, but some infeasibilities (primal, dual or bound) exceed tolerances due to scaling or preprocessing.",
+    "FEASIBLE": "The problem is feasible. This status is displayed when the IIS=TRUE option is specified and the problem is feasible.",
+    "INFEASIBLE": "The problem is infeasible.",
+    "UNBOUNDED": "The problem is unbounded.",
+    "INFEASIBLE_OR_UNBOUNDED": "The problem is infeasible or unbounded.",
+    "SOLUTION_LIM": "The solver reached the maximum number of solutions specified by the MAXSOLS= option.",
+    "NODE_LIM_SOL": "The solver reached the maximum number of nodes specified by the MAXNODES= option and found a solution.",
+    "NODE_LIM_NOSOL": "The solver reached the maximum number of nodes specified by the MAXNODES= option and did not find a solution.",
+    "ITERATION_LIMIT_REACHED": "The maximum allowable number of iterations was reached.",
+    "TIME_LIM_SOL": "The solver reached the execution time limit specified by the MAXTIME= option and found a solution.",
+    "TIME_LIM_NOSOL": "The solver reached the execution time limit specified by the MAXTIME= option and did not find a solution.",
+    "TIME_LIMIT_REACHED": "The solver reached its execution time limit.",
+    "ABORTED": "The solver was interrupted externally.",
+    "ABORT_SOL": "The solver was stopped by the user but still found a solution.",
+    "ABORT_NOSOL": "The solver was stopped by the user and did not find a solution.",
+    "OUTMEM_SOL": "The solver ran out of memory but still found a solution.",
+    "OUTMEM_NOSOL": "The solver ran out of memory and either did not find a solution or failed to output the solution due to insufficient memory.",
+    "FAILED": "The solver failed to converge, possibly due to numerical issues.",
+    "FAIL_SOL": "The solver stopped due to errors but still found a solution.",
+    "FAIL_NOSOL": "The solver stopped due to errors and did not find a solution.",
+}
+
+
+@SolverFactory.register("sas", doc="The SAS LP/MIP solver")
+class SAS(OptSolver):
+    """The SAS optimization solver"""
+
+    def __new__(cls, *args, **kwds):
+        mode = kwds.pop("solver_io", None)
+        if mode != None:
+            return SolverFactory(mode, **kwds)
+        else:
+            # Choose solver factory automatically
+            # based on what can be loaded.
+            s = SolverFactory("_sas94", **kwds)
+            if not s.available():
+                s = SolverFactory("_sascas", **kwds)
+            return s
+
+
+class SASAbc(ABC, OptSolver):
+    """Abstract base class for the SAS solver interfaces. Simply to avoid code duplication."""
+
+    def __init__(self, **kwds):
+        """Initialize the SAS solver interfaces."""
+        kwds["type"] = "sas"
+        super(SASAbc, self).__init__(**kwds)
+
+        #
+        # Set up valid problem formats and valid results for each
+        # problem format
+        #
+        self._valid_problem_formats = [ProblemFormat.mps]
+        self._valid_result_formats = {ProblemFormat.mps: [ResultsFormat.soln]}
+
+        self._keepfiles = False
+        self._capabilities.linear = True
+        self._capabilities.integer = True
+
+        super(SASAbc, self).set_problem_format(ProblemFormat.mps)
+
+    def _presolve(self, *args, **kwds):
+        """Set things up for the actual solve."""
+        # create a context in the temporary file manager for
+        # this plugin - is "pop"ed in the _postsolve method.
+        TempfileManager.push()
+
+        # Get the warmstart flag
+        self.warmstart_flag = kwds.pop("warmstart", False)
+
+        # Call parent presolve function
+        super(SASAbc, self)._presolve(*args, **kwds)
+
+        # Store the model, too bad this is not done in the base class
+        for arg in args:
+            if isinstance(arg, (BlockData, IBlock)):
+                # Store the instance
+                self._instance = arg
+                self._vars = []
+                for block in self._instance.block_data_objects(active=True):
+                    for vardata in block.component_data_objects(
+                        Var, active=True, descend_into=False
+                    ):
+                        self._vars.append(vardata)
+                # Store the symbol map, we need this for example when writing the warmstart file
+                if isinstance(self._instance, IBlock):
+                    self._smap = getattr(self._instance, "._symbol_maps")[self._smap_id]
+                else:
+                    self._smap = self._instance.solutions.symbol_map[self._smap_id]
+
+        # Create the primalin data
+        if self.warmstart_flag:
+            filename = self._warm_start_file_name = TempfileManager.create_tempfile(
+                ".sol", text=True
+            )
+            smap = self._smap
+            numWritten = 0
+            with open(filename, "w") as file:
+                file.write("_VAR_,_VALUE_\n")
+                for var in self._vars:
+                    if (var.value is not None) and (id(var) in smap.byObject):
+                        name = smap.byObject[id(var)]
+                        file.write(
+                            "{name},{value}\n".format(name=name, value=var.value)
+                        )
+                        numWritten += 1
+            if numWritten == 0:
+                # No solution available, disable warmstart
+                self.warmstart_flag = False
+
+    def available(self, exception_flag=False):
+        """True if the solver is available"""
+        return self._python_api_exists
+
+    def _has_integer_variables(self):
+        """True if the problem has integer variables."""
+        for vardata in self._vars:
+            if vardata.is_binary() or vardata.is_integer():
+                return True
+        return False
+
+    def _create_results_from_status(self, status, solution_status):
+        """Create a results object and set the status code and messages."""
+        results = SolverResults()
+        results.solver.name = "SAS"
+        results.solver.status = STATUS_TO_SOLVERSTATUS[status]
+        results.solver.hasSolution = False
+        if results.solver.status == SolverStatus.ok:
+            results.solver.termination_condition = SOLSTATUS_TO_TERMINATIONCOND[
+                solution_status
+            ]
+            results.solver.message = results.solver.termination_message = (
+                SOLSTATUS_TO_MESSAGE[solution_status]
+            )
+            results.solver.status = TerminationCondition.to_solver_status(
+                results.solver.termination_condition
+            )
+            if "OPTIMAL" in solution_status or "_SOL" in solution_status:
+                results.solver.hasSolution = True
+        elif results.solver.status == SolverStatus.aborted:
+            results.solver.termination_condition = TerminationCondition.userInterrupt
+            if solution_status != "ERROR":
+                results.solver.message = results.solver.termination_message = (
+                    SOLSTATUS_TO_MESSAGE[solution_status]
+                )
+        else:
+            results.solver.termination_condition = TerminationCondition.error
+            results.solver.message = results.solver.termination_message = (
+                SOLSTATUS_TO_MESSAGE["FAILED"]
+            )
+        return results
+
+    @abstractmethod
+    def _apply_solver(self):
+        pass
+
+    def _postsolve(self):
+        """Clean up at the end, especially the temp files."""
+        # Let the base class deal with returning results.
+        results = super(SASAbc, self)._postsolve()
+
+        # Finally, clean any temporary files registered with the temp file
+        # manager, created populated *directly* by this plugin. does not
+        # include, for example, the execution script. but does include
+        # the warm-start file.
+        TempfileManager.pop(remove=not self._keepfiles)
+
+        return results
+
+    def warm_start_capable(self):
+        """True if the solver interface supports MILP warmstarting."""
+        return True
+
+
+@SolverFactory.register("_sas94", doc="SAS 9.4 interface")
+class SAS94(SASAbc):
+    """
+    Solver interface for SAS 9.4 using saspy. See the saspy documentation about
+    how to create a connection.
+    The swat connection options can be specified on the SolverFactory call.
+    """
+
+    def __init__(self, **kwds):
+        """Initialize the solver interface and see if the saspy package is available."""
+        super(SAS94, self).__init__(**kwds)
+
+        try:
+            import saspy
+
+            self._sas = saspy
+        except ImportError:
+            self._python_api_exists = False
+        except Exception as e:
+            self._python_api_exists = False
+            # For other exceptions, raise it so that it does not get lost
+            raise e
+        else:
+            self._python_api_exists = True
+            self._sas.logger.setLevel(logger.level)
+
+        # Store other options for the SAS session
+        self._session_options = kwds
+
+        # Create the session
+        try:
+            self._sas_session = self._sas.SASsession(**self._session_options)
+        except:
+            self._sas_session = None
+
+    def __del__(self):
+        # Close the session, if we created one
+        if self._sas_session:
+            self._sas_session.endsas()
+            del self._sas_session
+
+    def _create_statement_str(self, statement):
+        """Helper function to create the strings for the statements of the proc OPTLP/OPTMILP code."""
+        stmt = self.options.pop(statement, None)
+        if stmt:
+            return (
+                statement.strip()
+                + " "
+                + " ".join(option + "=" + str(value) for option, value in stmt.items())
+                + ";"
+            )
+        else:
+            return ""
+
+    def sas_version(self):
+        return self._sasver
+
+    def _apply_solver(self):
+        """ "Prepare the options and run the solver. Then store the data to be returned."""
+        logger.debug("Running SAS")
+
+        # Set return code to issue an error if we get interrupted
+        self._rc = -1
+
+        # Figure out if the problem has integer variables
+        with_opt = self.options.pop("with", None)
+        if with_opt == "lp":
+            proc = "OPTLP"
+        elif with_opt == "milp":
+            proc = "OPTMILP"
+        else:
+            # Check if there are integer variables, this might be slow
+            proc = "OPTMILP" if self._has_integer_variables() else "OPTLP"
+
+        # Get the rootnode options
+        decomp_str = self._create_statement_str("decomp")
+        decompmaster_str = self._create_statement_str("decompmaster")
+        decompmasterip_str = self._create_statement_str("decompmasterip")
+        decompsubprob_str = self._create_statement_str("decompsubprob")
+        rootnode_str = self._create_statement_str("rootnode")
+
+        # Get a unique identifier, always use the same with different prefixes
+        unique = uuid.uuid4().hex[:16]
+
+        # Create unique filename for output datasets
+        primalout_dataset_name = "pout" + unique
+        dualout_dataset_name = "dout" + unique
+        primalin_dataset_name = None
+
+        # Handle warmstart
+        warmstart_str = ""
+        if self.warmstart_flag:
+            # Set the warmstart basis option
+            primalin_dataset_name = "pin" + unique
+            if proc != "OPTLP":
+                warmstart_str = """
+                                proc import datafile='{primalin}'
+                                    out={primalin_dataset_name}
+                                    dbms=csv
+                                    replace;
+                                    getnames=yes;
+                                    run;
+                                """.format(
+                    primalin=self._warm_start_file_name,
+                    primalin_dataset_name=primalin_dataset_name,
+                )
+                self.options["primalin"] = primalin_dataset_name
+
+        # Convert options to string
+        opt_str = " ".join(
+            option + "=" + str(value) for option, value in self.options.items()
+        )
+
+        # Set some SAS options to make the log more clean
+        sas_options = "option notes nonumber nodate nosource pagesize=max;"
+
+        # Get the current SAS session, submit the code and return the results
+        if not self._sas_session:
+            sas = self._sas_session = self._sas.SASsession(**self._session_options)
+        else:
+            sas = self._sas_session
+
+        # Find the version of 9.4 we are using
+        self._sasver = sas.sasver
+
+        # Upload files, only if not accessible locally
+        upload_mps = False
+        if not sas.file_info(self._problem_files[0], quiet=True):
+            sas.upload(self._problem_files[0], self._problem_files[0], overwrite=True)
+            upload_mps = True
+
+        upload_pin = False
+        if self.warmstart_flag and not sas.file_info(
+            self._warm_start_file_name, quiet=True
+        ):
+            sas.upload(
+                self._warm_start_file_name, self._warm_start_file_name, overwrite=True
+            )
+            upload_pin = True
+
+        # Using a function call to make it easier to mock the version check
+        major_version = self.sas_version()[0]
+        minor_version = self.sas_version().split("M", 1)[1][0]
+        if major_version == "9" and int(minor_version) < 5:
+            raise NotImplementedError(
+                "Support for SAS 9.4 M4 and earlier is not implemented."
+            )
+        elif major_version == "9" and int(minor_version) == 5:
+            # In 9.4M5 we have to create an MPS data set from an MPS file first
+            # Earlier versions will not work because the MPS format in incompatible
+            mps_dataset_name = "mps" + unique
+            res = sas.submit(
+                """
+                            {sas_options}
+                            {warmstart}
+                            %MPS2SASD(MPSFILE="{mpsfile}", OUTDATA={mps_dataset_name}, MAXLEN=256, FORMAT=FREE);
+                            proc {proc} data={mps_dataset_name} {options} primalout={primalout_dataset_name} dualout={dualout_dataset_name};
+                            {decomp}
+                            {decompmaster}
+                            {decompmasterip}
+                            {decompsubprob}
+                            {rootnode}
+                            run;
+                            """.format(
+                    sas_options=sas_options,
+                    warmstart=warmstart_str,
+                    proc=proc,
+                    mpsfile=self._problem_files[0],
+                    mps_dataset_name=mps_dataset_name,
+                    options=opt_str,
+                    primalout_dataset_name=primalout_dataset_name,
+                    dualout_dataset_name=dualout_dataset_name,
+                    decomp=decomp_str,
+                    decompmaster=decompmaster_str,
+                    decompmasterip=decompmasterip_str,
+                    decompsubprob=decompsubprob_str,
+                    rootnode=rootnode_str,
+                ),
+                results="TEXT",
+            )
+            sas.sasdata(mps_dataset_name).delete(quiet=True)
+        else:
+            # Since 9.4M6+ optlp/optmilp can read mps files directly (this includes Viya-based local installs)
+            res = sas.submit(
+                """
+                            {sas_options}
+                            {warmstart}
+                            proc {proc} mpsfile=\"{mpsfile}\" {options} primalout={primalout_dataset_name} dualout={dualout_dataset_name};
+                            {decomp}
+                            {decompmaster}
+                            {decompmasterip}
+                            {decompsubprob}
+                            {rootnode}
+                            run;
+                            """.format(
+                    sas_options=sas_options,
+                    warmstart=warmstart_str,
+                    proc=proc,
+                    mpsfile=self._problem_files[0],
+                    options=opt_str,
+                    primalout_dataset_name=primalout_dataset_name,
+                    dualout_dataset_name=dualout_dataset_name,
+                    decomp=decomp_str,
+                    decompmaster=decompmaster_str,
+                    decompmasterip=decompmasterip_str,
+                    decompsubprob=decompsubprob_str,
+                    rootnode=rootnode_str,
+                ),
+                results="TEXT",
+            )
+
+        # Delete uploaded file
+        if upload_mps:
+            sas.file_delete(self._problem_files[0], quiet=True)
+        if self.warmstart_flag and upload_pin:
+            sas.file_delete(self._warm_start_file_name, quiet=True)
+
+        # Store log and ODS output
+        self._log = res["LOG"]
+        self._lst = res["LST"]
+        if "ERROR 22-322: Syntax error" in self._log:
+            raise ValueError(
+                "An option passed to the SAS solver caused a syntax error: {log}".format(
+                    log=self._log
+                )
+            )
+        else:
+            # Print log if requested by the user, only if we did not already print it
+            if self._tee:
+                print(self._log)
+        self._macro = dict(
+            (key.strip(), value.strip())
+            for key, value in (
+                pair.split("=") for pair in sas.symget("_OR" + proc + "_").split()
+            )
+        )
+        if self._macro.get("STATUS", "ERROR") == "OK":
+            primal_out = sas.sd2df(primalout_dataset_name)
+            dual_out = sas.sd2df(dualout_dataset_name)
+
+        # Delete data sets, they will go away automatically, but does not hurt to delete them
+        if primalin_dataset_name:
+            sas.sasdata(primalin_dataset_name).delete(quiet=True)
+        sas.sasdata(primalout_dataset_name).delete(quiet=True)
+        sas.sasdata(dualout_dataset_name).delete(quiet=True)
+
+        # Prepare the solver results
+        results = self.results = self._create_results_from_status(
+            self._macro.get("STATUS", "ERROR"),
+            self._macro.get("SOLUTION_STATUS", "ERROR"),
+        )
+
+        if "Objective Sense            Maximization" in self._lst:
+            results.problem.sense = ProblemSense.maximize
+        else:
+            results.problem.sense = ProblemSense.minimize
+
+        # Prepare the solution information
+        if results.solver.hasSolution:
+            sol = results.solution.add()
+
+            # Store status in solution
+            sol.status = SolutionStatus.feasible
+            sol.termination_condition = SOLSTATUS_TO_TERMINATIONCOND[
+                self._macro.get("SOLUTION_STATUS", "ERROR")
+            ]
+
+            # Store objective value in solution
+            sol.objective["__default_objective__"] = {"Value": self._macro["OBJECTIVE"]}
+
+            if proc == "OPTLP":
+                # Convert primal out data set to variable dictionary
+                # Use pandas functions for efficiency
+                primal_out = primal_out[["_VAR_", "_VALUE_", "_STATUS_", "_R_COST_"]]
+                primal_out = primal_out.set_index("_VAR_", drop=True)
+                primal_out = primal_out.rename(
+                    {"_VALUE_": "Value", "_STATUS_": "Status", "_R_COST_": "rc"},
+                    axis="columns",
+                )
+                sol.variable = primal_out.to_dict("index")
+
+                # Convert dual out data set to constraint dictionary
+                # Use pandas functions for efficiency
+                dual_out = dual_out[["_ROW_", "_VALUE_", "_STATUS_", "_ACTIVITY_"]]
+                dual_out = dual_out.set_index("_ROW_", drop=True)
+                dual_out = dual_out.rename(
+                    {"_VALUE_": "dual", "_STATUS_": "Status", "_ACTIVITY_": "slack"},
+                    axis="columns",
+                )
+                sol.constraint = dual_out.to_dict("index")
+            else:
+                # Convert primal out data set to variable dictionary
+                # Use pandas functions for efficiency
+                primal_out = primal_out[["_VAR_", "_VALUE_"]]
+                primal_out = primal_out.set_index("_VAR_", drop=True)
+                primal_out = primal_out.rename({"_VALUE_": "Value"}, axis="columns")
+                sol.variable = primal_out.to_dict("index")
+
+        self._rc = 0
+        return Bunch(rc=self._rc, log=self._log)
+
+
+@SolverFactory.register("_sascas", doc="SAS Viya CAS Server interface")
+class SASCAS(SASAbc):
+    """
+    Solver interface connection to a SAS Viya CAS server using swat.
+    See the documentation for the swat package about how to create a connection.
+    The swat connection options can be specified on the SolverFactory call.
+    """
+
+    def __init__(self, **kwds):
+        """Initialize and try to load the swat package."""
+        super(SASCAS, self).__init__(**kwds)
+
+        try:
+            import swat
+
+            self._sas = swat
+        except ImportError:
+            self._python_api_exists = False
+        except Exception as e:
+            self._python_api_exists = False
+            # For other exceptions, raise it so that it does not get lost
+            raise e
+        else:
+            self._python_api_exists = True
+
+        self._session_options = kwds
+
+        # Create the session
+        try:
+            self._sas_session = self._sas.CAS(**self._session_options)
+        except:
+            self._sas_session = None
+
+    def __del__(self):
+        # Close the session, if we created one
+        if self._sas_session:
+            self._sas_session.close()
+            del self._sas_session
+
+    def _uploadMpsFile(self, s, unique):
+        # Declare a unique table name for the mps table
+        mpsdata_table_name = "mps" + unique
+
+        # Upload mps file to CAS, if the file is larger than 2 GB, we need to use convertMps instead of loadMps
+        # Note that technically it is 2 Gibibytes file size that trigger the issue, but 2 GB is the safer threshold
+        if stat(self._problem_files[0]).st_size > 2e9:
+            # For files larger than 2 GB (this is a limitation of the loadMps action used in the else part).
+            # Use convertMPS, first create file for upload.
+            mpsWithIdFileName = TempfileManager.create_tempfile(".mps.csv", text=True)
+            with open(mpsWithIdFileName, "w") as mpsWithId:
+                mpsWithId.write("_ID_\tText\n")
+                with open(self._problem_files[0], "r") as f:
+                    id = 0
+                    for line in f:
+                        id += 1
+                        mpsWithId.write(str(id) + "\t" + line.rstrip() + "\n")
+
+            # Upload .mps.csv file
+            mpscsv_table_name = "csv" + unique
+            s.upload_file(
+                mpsWithIdFileName,
+                casout={"name": mpscsv_table_name, "replace": True},
+                importoptions={"filetype": "CSV", "delimiter": "\t"},
+            )
+
+            # Convert .mps.csv file to .mps
+            s.optimization.convertMps(
+                data=mpscsv_table_name,
+                casOut={"name": mpsdata_table_name, "replace": True},
+                format="FREE",
+                maxLength=256,
+            )
+
+            # Delete the table we don't need anymore
+            if mpscsv_table_name:
+                s.dropTable(name=mpscsv_table_name, quiet=True)
+        else:
+            # For small files (less than 2 GB), use loadMps
+            with open(self._problem_files[0], "r") as mps_file:
+                s.optimization.loadMps(
+                    mpsFileString=mps_file.read(),
+                    casout={"name": mpsdata_table_name, "replace": True},
+                    format="FREE",
+                    maxLength=256,
+                )
+        return mpsdata_table_name
+
+    def _uploadPrimalin(self, s, unique):
+        # Upload warmstart file to CAS with a unique name
+        primalin_table_name = "pin" + unique
+        s.upload_file(
+            self._warm_start_file_name,
+            casout={"name": primalin_table_name, "replace": True},
+            importoptions={"filetype": "CSV"},
+        )
+        self.options["primalin"] = primalin_table_name
+        return primalin_table_name
+
+    def _retrieveSolution(
+        self, s, r, results, action, primalout_table_name, dualout_table_name
+    ):
+        # Create solution
+        sol = results.solution.add()
+
+        # Store status in solution
+        sol.status = SolutionStatus.feasible
+        sol.termination_condition = SOLSTATUS_TO_TERMINATIONCOND[
+            r.get("solutionStatus", "ERROR")
+        ]
+
+        # Store objective value in solution
+        sol.objective["__default_objective__"] = {"Value": r["objective"]}
+
+        if action == "solveMilp":
+            primal_out = s.CASTable(name=primalout_table_name)
+            # Use pandas functions for efficiency
+            primal_out = primal_out[["_VAR_", "_VALUE_"]]
+            sol.variable = {}
+            for row in primal_out.itertuples(index=False):
+                sol.variable[row[0]] = {"Value": row[1]}
+        else:
+            # Convert primal out data set to variable dictionary
+            # Use panda functions for efficiency
+            primal_out = s.CASTable(name=primalout_table_name)
+            primal_out = primal_out[["_VAR_", "_VALUE_", "_STATUS_", "_R_COST_"]]
+            sol.variable = {}
+            for row in primal_out.itertuples(index=False):
+                sol.variable[row[0]] = {"Value": row[1], "Status": row[2], "rc": row[3]}
+
+            # Convert dual out data set to constraint dictionary
+            # Use pandas functions for efficiency
+            dual_out = s.CASTable(name=dualout_table_name)
+            dual_out = dual_out[["_ROW_", "_VALUE_", "_STATUS_", "_ACTIVITY_"]]
+            sol.constraint = {}
+            for row in dual_out.itertuples(index=False):
+                sol.constraint[row[0]] = {
+                    "dual": row[1],
+                    "Status": row[2],
+                    "slack": row[3],
+                }
+
+    def _apply_solver(self):
+        """ "Prepare the options and run the solver. Then store the data to be returned."""
+        logger.debug("Running SAS Viya")
+
+        # Set return code to issue an error if we get interrupted
+        self._rc = -1
+
+        # Figure out if the problem has integer variables
+        with_opt = self.options.pop("with", None)
+        if with_opt == "lp":
+            action = "solveLp"
+        elif with_opt == "milp":
+            action = "solveMilp"
+        else:
+            # Check if there are integer variables, this might be slow
+            action = "solveMilp" if self._has_integer_variables() else "solveLp"
+
+        # Get a unique identifier, always use the same with different prefixes
+        unique = uuid.uuid4().hex[:16]
+
+        # Creat the output stream, we want to print to a log string as well as to the console
+        self._log = StringIO()
+        ostreams = [LogStream(level=logging.INFO, logger=logger)]
+        ostreams.append(self._log)
+        if self._tee:
+            ostreams.append(sys.stdout)
+
+        # Connect to CAS server
+        with TeeStream(*ostreams) as t:
+            with capture_output(output=t.STDOUT, capture_fd=False):
+                s = self._sas_session
+                if s == None:
+                    s = self._sas_session = self._sas.CAS(**self._session_options)
+                try:
+                    # Load the optimization action set
+                    s.loadactionset("optimization")
+
+                    mpsdata_table_name = self._uploadMpsFile(s, unique)
+
+                    primalin_table_name = None
+                    if self.warmstart_flag:
+                        primalin_table_name = self._uploadPrimalin(s, unique)
+
+                    # Define output table names
+                    primalout_table_name = "pout" + unique
+                    dualout_table_name = None
+
+                    # Solve the problem in CAS
+                    if action == "solveMilp":
+                        r = s.optimization.solveMilp(
+                            data={"name": mpsdata_table_name},
+                            primalOut={"name": primalout_table_name, "replace": True},
+                            **self.options
+                        )
+                    else:
+                        dualout_table_name = "dout" + unique
+                        r = s.optimization.solveLp(
+                            data={"name": mpsdata_table_name},
+                            primalOut={"name": primalout_table_name, "replace": True},
+                            dualOut={"name": dualout_table_name, "replace": True},
+                            **self.options
+                        )
+
+                    # Prepare the solver results
+                    if r:
+                        # Get back the primal and dual solution data sets
+                        results = self.results = self._create_results_from_status(
+                            r.get("status", "ERROR"), r.get("solutionStatus", "ERROR")
+                        )
+
+                        if results.solver.status != SolverStatus.error:
+                            if r.ProblemSummary["cValue1"][1] == "Maximization":
+                                results.problem.sense = ProblemSense.maximize
+                            else:
+                                results.problem.sense = ProblemSense.minimize
+
+                            # Prepare the solution information
+                            if results.solver.hasSolution:
+                                self._retrieveSolution(
+                                    s,
+                                    r,
+                                    results,
+                                    action,
+                                    primalout_table_name,
+                                    dualout_table_name,
+                                )
+                        else:
+                            raise ValueError("The SAS solver returned an error status.")
+                    else:
+                        results = self.results = SolverResults()
+                        results.solver.name = "SAS"
+                        results.solver.status = SolverStatus.error
+                        raise ValueError(
+                            "An option passed to the SAS solver caused a syntax error."
+                        )
+
+                finally:
+                    if mpsdata_table_name:
+                        s.dropTable(name=mpsdata_table_name, quiet=True)
+                    if primalin_table_name:
+                        s.dropTable(name=primalin_table_name, quiet=True)
+                    if primalout_table_name:
+                        s.dropTable(name=primalout_table_name, quiet=True)
+                    if dualout_table_name:
+                        s.dropTable(name=dualout_table_name, quiet=True)
+
+        self._log = self._log.getvalue()
+        self._rc = 0
+        return Bunch(rc=self._rc, log=self._log)
diff --git a/pyomo/solvers/plugins/solvers/SCIPAMPL.py b/pyomo/solvers/plugins/solvers/SCIPAMPL.py
index 9898b9cdd90..98dad4ca5fd 100644
--- a/pyomo/solvers/plugins/solvers/SCIPAMPL.py
+++ b/pyomo/solvers/plugins/solvers/SCIPAMPL.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -20,12 +20,7 @@
 
 from pyomo.opt.base import ProblemFormat, ResultsFormat
 from pyomo.opt.base.solvers import _extract_version, SolverFactory
-from pyomo.opt.results import (
-    SolverStatus,
-    TerminationCondition,
-    SolutionStatus,
-    ProblemSense,
-)
+from pyomo.opt.results import SolverStatus, TerminationCondition, SolutionStatus
 from pyomo.opt.solver import SystemCallSolver
 
 import logging
@@ -103,7 +98,7 @@ def _get_version(self, solver_exec=None):
                 return _extract_version('')
         results = subprocess.run(
             [solver_exec, "--version"],
-            timeout=1,
+            timeout=self._version_timeout,
             stdout=subprocess.PIPE,
             stderr=subprocess.STDOUT,
             universal_newlines=True,
@@ -374,9 +369,11 @@ def _postsolve(self):
             if len(results.solution) > 0:
                 results.solution(0).status = SolutionStatus.optimal
             try:
-                if results.problem.sense == ProblemSense.minimize:
+                if results.solver.primal_bound < results.solver.dual_bound:
                     results.problem.lower_bound = results.solver.primal_bound
+                    results.problem.upper_bound = results.solver.dual_bound
                 else:
+                    results.problem.lower_bound = results.solver.dual_bound
                     results.problem.upper_bound = results.solver.primal_bound
             except AttributeError:
                 """
@@ -455,7 +452,7 @@ def read_scip_log(filename: str):
         solver_status = scip_lines[0][colon_position + 2 : scip_lines[0].index('\n')]
 
         solving_time = float(
-            scip_lines[1][colon_position + 2 : scip_lines[1].index('\n')]
+            scip_lines[1][colon_position + 2 : scip_lines[1].index('\n')].split(' ')[0]
         )
 
         try:
diff --git a/pyomo/solvers/plugins/solvers/XPRESS.py b/pyomo/solvers/plugins/solvers/XPRESS.py
index 6ab51cfbbf3..2c16d971144 100644
--- a/pyomo/solvers/plugins/solvers/XPRESS.py
+++ b/pyomo/solvers/plugins/solvers/XPRESS.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.opt.base import OptSolver
 from pyomo.opt.base.solvers import SolverFactory
 import logging
diff --git a/pyomo/solvers/plugins/solvers/__init__.py b/pyomo/solvers/plugins/solvers/__init__.py
index c5fbfa97e42..a3918dce5cc 100644
--- a/pyomo/solvers/plugins/solvers/__init__.py
+++ b/pyomo/solvers/plugins/solvers/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -30,3 +30,4 @@
 import pyomo.solvers.plugins.solvers.mosek_persistent
 import pyomo.solvers.plugins.solvers.xpress_direct
 import pyomo.solvers.plugins.solvers.xpress_persistent
+import pyomo.solvers.plugins.solvers.SAS
diff --git a/pyomo/solvers/plugins/solvers/cplex_direct.py b/pyomo/solvers/plugins/solvers/cplex_direct.py
index 308d3438329..93d8015514e 100644
--- a/pyomo/solvers/plugins/solvers/cplex_direct.py
+++ b/pyomo/solvers/plugins/solvers/cplex_direct.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/plugins/solvers/cplex_persistent.py b/pyomo/solvers/plugins/solvers/cplex_persistent.py
index a7fdcc45ade..754dadc09e2 100644
--- a/pyomo/solvers/plugins/solvers/cplex_persistent.py
+++ b/pyomo/solvers/plugins/solvers/cplex_persistent.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -82,7 +82,7 @@ def update_var(self, var):
 
         Parameters
         ----------
-        var: Var (scalar Var or single _VarData)
+        var: Var (scalar Var or single VarData)
 
         """
         # see PR #366 for discussion about handling indexed
@@ -130,7 +130,7 @@ def _add_column(self, var, obj_coef, constraints, coefficients):
 
         Parameters
         ----------
-        var: Var (scalar Var or single _VarData)
+        var: Var (scalar Var or single VarData)
         obj_coef: float
         constraints: list of solver constraints
         coefficients: list of coefficients to put on var in the associated constraint
diff --git a/pyomo/solvers/plugins/solvers/direct_or_persistent_solver.py b/pyomo/solvers/plugins/solvers/direct_or_persistent_solver.py
index 09bbfbda70f..de38a0372d0 100644
--- a/pyomo/solvers/plugins/solvers/direct_or_persistent_solver.py
+++ b/pyomo/solvers/plugins/solvers/direct_or_persistent_solver.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -10,7 +10,7 @@
 #  ___________________________________________________________________________
 
 from pyomo.core.base.PyomoModel import Model
-from pyomo.core.base.block import Block, _BlockData
+from pyomo.core.base.block import Block, BlockData
 from pyomo.core.kernel.block import IBlock
 from pyomo.opt.base.solvers import OptSolver
 from pyomo.core.base import SymbolMap, NumericLabeler, TextLabeler
@@ -177,7 +177,7 @@ def _postsolve(self):
     """ This method should be implemented by subclasses."""
 
     def _set_instance(self, model, kwds={}):
-        if not isinstance(model, (Model, IBlock, Block, _BlockData)):
+        if not isinstance(model, (Model, IBlock, Block, BlockData)):
             msg = (
                 "The problem instance supplied to the {0} plugin "
                 "'_presolve' method must be a Model or a Block".format(type(self))
diff --git a/pyomo/solvers/plugins/solvers/direct_solver.py b/pyomo/solvers/plugins/solvers/direct_solver.py
index 4f90a753fe6..609a81b2018 100644
--- a/pyomo/solvers/plugins/solvers/direct_solver.py
+++ b/pyomo/solvers/plugins/solvers/direct_solver.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -15,7 +15,7 @@
 from pyomo.solvers.plugins.solvers.direct_or_persistent_solver import (
     DirectOrPersistentSolver,
 )
-from pyomo.core.base.block import _BlockData
+from pyomo.core.base.block import BlockData
 from pyomo.core.kernel.block import IBlock
 from pyomo.core.base.suffix import active_import_suffix_generator
 from pyomo.core.kernel.suffix import import_suffix_generator
@@ -79,8 +79,8 @@ def solve(self, *args, **kwds):
         #
         _model = None
         for arg in args:
-            if isinstance(arg, (_BlockData, IBlock)):
-                if isinstance(arg, _BlockData):
+            if isinstance(arg, (BlockData, IBlock)):
+                if isinstance(arg, BlockData):
                     if not arg.is_constructed():
                         raise RuntimeError(
                             "Attempting to solve model=%s with unconstructed "
@@ -89,7 +89,7 @@ def solve(self, *args, **kwds):
 
                 _model = arg
                 # import suffixes must be on the top-level model
-                if isinstance(arg, _BlockData):
+                if isinstance(arg, BlockData):
                     model_suffixes = list(
                         name for (name, comp) in active_import_suffix_generator(arg)
                     )
diff --git a/pyomo/solvers/plugins/solvers/gurobi_direct.py b/pyomo/solvers/plugins/solvers/gurobi_direct.py
index 54ea9111508..ed66a4e0e7b 100644
--- a/pyomo/solvers/plugins/solvers/gurobi_direct.py
+++ b/pyomo/solvers/plugins/solvers/gurobi_direct.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -493,9 +493,8 @@ def _add_constraint(self, con):
         if not con.active:
             return None
 
-        if is_fixed(con.body):
-            if self._skip_trivial_constraints:
-                return None
+        if self._skip_trivial_constraints and is_fixed(con.body):
+            return None
 
         conname = self._symbol_map.getSymbol(con, self._labeler)
 
diff --git a/pyomo/solvers/plugins/solvers/gurobi_persistent.py b/pyomo/solvers/plugins/solvers/gurobi_persistent.py
index 382cb7c4e6d..94a2ac6b734 100644
--- a/pyomo/solvers/plugins/solvers/gurobi_persistent.py
+++ b/pyomo/solvers/plugins/solvers/gurobi_persistent.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -111,7 +111,7 @@ def update_var(self, var):
 
         Parameters
         ----------
-        var: Var (scalar Var or single _VarData)
+        var: Var (scalar Var or single VarData)
 
         """
         # see PR #366 for discussion about handling indexed
@@ -157,7 +157,7 @@ def set_linear_constraint_attr(self, con, attr, val):
 
         Parameters
         ----------
-        con: pyomo.core.base.constraint._GeneralConstraintData
+        con: pyomo.core.base.constraint.ConstraintData
             The pyomo constraint for which the corresponding gurobi constraint attribute
             should be modified.
         attr: str
@@ -192,7 +192,7 @@ def set_var_attr(self, var, attr, val):
 
         Parameters
         ----------
-        con: pyomo.core.base.var._GeneralVarData
+        con: pyomo.core.base.var.VarData
             The pyomo var for which the corresponding gurobi var attribute
             should be modified.
         attr: str
@@ -342,7 +342,7 @@ def get_var_attr(self, var, attr):
 
         Parameters
         ----------
-        var: pyomo.core.base.var._GeneralVarData
+        var: pyomo.core.base.var.VarData
             The pyomo var for which the corresponding gurobi var attribute
             should be retrieved.
         attr: str
@@ -384,7 +384,7 @@ def get_linear_constraint_attr(self, con, attr):
 
         Parameters
         ----------
-        con: pyomo.core.base.constraint._GeneralConstraintData
+        con: pyomo.core.base.constraint.ConstraintData
             The pyomo constraint for which the corresponding gurobi constraint attribute
             should be retrieved.
         attr: str
@@ -413,7 +413,7 @@ def get_sos_attr(self, con, attr):
 
         Parameters
         ----------
-        con: pyomo.core.base.sos._SOSConstraintData
+        con: pyomo.core.base.sos.SOSConstraintData
             The pyomo SOS constraint for which the corresponding gurobi SOS constraint attribute
             should be retrieved.
         attr: str
@@ -431,7 +431,7 @@ def get_quadratic_constraint_attr(self, con, attr):
 
         Parameters
         ----------
-        con: pyomo.core.base.constraint._GeneralConstraintData
+        con: pyomo.core.base.constraint.ConstraintData
             The pyomo constraint for which the corresponding gurobi constraint attribute
             should be retrieved.
         attr: str
@@ -569,7 +569,7 @@ def cbCut(self, con):
 
         Parameters
         ----------
-        con: pyomo.core.base.constraint._GeneralConstraintData
+        con: pyomo.core.base.constraint.ConstraintData
             The cut to add
         """
         if not con.active:
@@ -647,7 +647,7 @@ def cbLazy(self, con):
         """
         Parameters
         ----------
-        con: pyomo.core.base.constraint._GeneralConstraintData
+        con: pyomo.core.base.constraint.ConstraintData
             The lazy constraint to add
         """
         if not con.active:
@@ -710,7 +710,7 @@ def _add_column(self, var, obj_coef, constraints, coefficients):
 
         Parameters
         ----------
-        var: Var (scalar Var or single _VarData)
+        var: Var (scalar Var or single VarData)
         obj_coef: float
         constraints: list of solver constraints
         coefficients: list of coefficients to put on var in the associated constraint
diff --git a/pyomo/solvers/plugins/solvers/mosek_direct.py b/pyomo/solvers/plugins/solvers/mosek_direct.py
index 4c0718bfe74..025c71d36f0 100644
--- a/pyomo/solvers/plugins/solvers/mosek_direct.py
+++ b/pyomo/solvers/plugins/solvers/mosek_direct.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -492,13 +492,10 @@ def _add_constraints(self, con_seq):
             ptrb = (0,) + ptre[:-1]
             asubs = tuple(itertools.chain.from_iterable(l_ids))
             avals = tuple(itertools.chain.from_iterable(l_coefs))
-            qcsubi = tuple(itertools.chain.from_iterable(q_is))
-            qcsubj = tuple(itertools.chain.from_iterable(q_js))
-            qcval = tuple(itertools.chain.from_iterable(q_vals))
-            qcsubk = tuple(i for i in sub for j in range(len(q_is[i - con_num])))
             self._solver_model.appendcons(num_lq)
             self._solver_model.putarowlist(sub, ptrb, ptre, asubs, avals)
-            self._solver_model.putqcon(qcsubk, qcsubi, qcsubj, qcval)
+            for k, i, j, v in zip(sub, q_is, q_js, q_vals):
+                self._solver_model.putqconk(k, i, j, v)
             self._solver_model.putconboundlist(sub, bound_types, lbs, ubs)
             for i, s_n in enumerate(sub_names):
                 self._solver_model.putconname(sub[i], s_n)
@@ -558,7 +555,7 @@ def _add_block(self, block):
 
         Parameters
         ----------
-        block: Block (scalar Block or single _BlockData)
+        block: Block (scalar Block or single BlockData)
         """
         var_seq = tuple(
             block.component_data_objects(
diff --git a/pyomo/solvers/plugins/solvers/mosek_persistent.py b/pyomo/solvers/plugins/solvers/mosek_persistent.py
index 6eaad564781..efcbb7dd9dd 100644
--- a/pyomo/solvers/plugins/solvers/mosek_persistent.py
+++ b/pyomo/solvers/plugins/solvers/mosek_persistent.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -85,7 +85,7 @@ def add_constraints(self, con_seq):
 
         Parameters
         ----------
-        con_seq: tuple/list of Constraint (scalar Constraint or single _ConstraintData)
+        con_seq: tuple/list of Constraint (scalar Constraint or single ConstraintData)
         """
         self._add_constraints(con_seq)
 
@@ -95,7 +95,7 @@ def remove_var(self, solver_var):
         This will keep any other model components intact.
         Parameters
         ----------
-        solver_var: Var (scalar Var or single _VarData)
+        solver_var: Var (scalar Var or single VarData)
         """
         self.remove_vars(solver_var)
 
@@ -106,7 +106,7 @@ def remove_vars(self, *solver_vars):
         This will keep any other model components intact.
         Parameters
         ----------
-        *solver_var: Var (scalar Var or single _VarData)
+        *solver_var: Var (scalar Var or single VarData)
         """
         try:
             var_ids = []
@@ -137,7 +137,7 @@ def remove_constraint(self, solver_con):
         To remove a conic-domain, you should use the remove_block method.
         Parameters
         ----------
-        solver_con: Constraint (scalar Constraint or single _ConstraintData)
+        solver_con: Constraint (scalar Constraint or single ConstraintData)
         """
         self.remove_constraints(solver_con)
 
@@ -151,7 +151,7 @@ def remove_constraints(self, *solver_cons):
 
         Parameters
         ----------
-        *solver_cons: Constraint (scalar Constraint or single _ConstraintData)
+        *solver_cons: Constraint (scalar Constraint or single ConstraintData)
         """
         lq_cons = tuple(
             itertools.filterfalse(lambda x: isinstance(x, _ConicBase), solver_cons)
@@ -205,7 +205,7 @@ def update_vars(self, *solver_vars):
         changing variable types and bounds.
         Parameters
         ----------
-        *solver_var: Constraint (scalar Constraint or single _ConstraintData)
+        *solver_var: Constraint (scalar Constraint or single ConstraintData)
         """
         try:
             var_ids = []
diff --git a/pyomo/solvers/plugins/solvers/persistent_solver.py b/pyomo/solvers/plugins/solvers/persistent_solver.py
index 141621d0a31..3c2a9e52eab 100644
--- a/pyomo/solvers/plugins/solvers/persistent_solver.py
+++ b/pyomo/solvers/plugins/solvers/persistent_solver.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -12,7 +12,7 @@
 from pyomo.solvers.plugins.solvers.direct_or_persistent_solver import (
     DirectOrPersistentSolver,
 )
-from pyomo.core.base.block import _BlockData
+from pyomo.core.base.block import BlockData
 from pyomo.core.kernel.block import IBlock
 from pyomo.core.base.suffix import active_import_suffix_generator
 from pyomo.core.kernel.suffix import import_suffix_generator
@@ -96,7 +96,7 @@ def add_block(self, block):
 
         Parameters
         ----------
-        block: Block (scalar Block or single _BlockData)
+        block: Block (scalar Block or single BlockData)
 
         """
         if self._pyomo_model is None:
@@ -132,7 +132,7 @@ def add_constraint(self, con):
 
         Parameters
         ----------
-        con: Constraint (scalar Constraint or single _ConstraintData)
+        con: Constraint (scalar Constraint or single ConstraintData)
 
         """
         if self._pyomo_model is None:
@@ -206,9 +206,9 @@ def add_column(self, model, var, obj_coef, constraints, coefficients):
         Parameters
         ----------
         model: pyomo ConcreteModel to which the column will be added
-        var: Var (scalar Var or single _VarData)
+        var: Var (scalar Var or single VarData)
         obj_coef: float, pyo.Param
-        constraints: list of scalar Constraints of single _ConstraintDatas
+        constraints: list of scalar Constraints of single ConstraintDatas
         coefficients: list of the coefficient to put on var in the associated constraint
 
         """
@@ -295,7 +295,7 @@ def remove_block(self, block):
 
         Parameters
         ----------
-        block: Block (scalar Block or a single _BlockData)
+        block: Block (scalar Block or a single BlockData)
 
         """
         # see PR #366 for discussion about handling indexed
@@ -328,7 +328,7 @@ def remove_constraint(self, con):
 
         Parameters
         ----------
-        con: Constraint (scalar Constraint or single _ConstraintData)
+        con: Constraint (scalar Constraint or single ConstraintData)
 
         """
         # see PR #366 for discussion about handling indexed
@@ -380,7 +380,7 @@ def remove_var(self, var):
 
         Parameters
         ----------
-        var: Var (scalar Var or single _VarData)
+        var: Var (scalar Var or single VarData)
 
         """
         # see PR #366 for discussion about handling indexed
@@ -455,7 +455,7 @@ def solve(self, *args, **kwds):
         self.available(exception_flag=True)
 
         # Collect suffix names to try and import from solution.
-        if isinstance(self._pyomo_model, _BlockData):
+        if isinstance(self._pyomo_model, BlockData):
             model_suffixes = list(
                 name
                 for (name, comp) in active_import_suffix_generator(self._pyomo_model)
diff --git a/pyomo/solvers/plugins/solvers/pywrapper.py b/pyomo/solvers/plugins/solvers/pywrapper.py
index 8f72e630a3d..c3ec2eaf709 100644
--- a/pyomo/solvers/plugins/solvers/pywrapper.py
+++ b/pyomo/solvers/plugins/solvers/pywrapper.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/plugins/solvers/xpress_direct.py b/pyomo/solvers/plugins/solvers/xpress_direct.py
index aa5a4ba1b4e..33a3c8d0282 100644
--- a/pyomo/solvers/plugins/solvers/xpress_direct.py
+++ b/pyomo/solvers/plugins/solvers/xpress_direct.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -667,9 +667,8 @@ def _add_constraint(self, con):
         if not con.active:
             return None
 
-        if is_fixed(con.body):
-            if self._skip_trivial_constraints:
-                return None
+        if self._skip_trivial_constraints and is_fixed(con.body):
+            return None
 
         conname = self._symbol_map.getSymbol(con, self._labeler)
 
@@ -1037,10 +1036,8 @@ def _load_slacks(self, cons_to_load=None):
             if xpress_con in self._range_constraints:
                 ## for xpress, the slack on a range constraint
                 ## is based on the upper bound
-                ## FIXME: This looks like a bug - there is no variable named
-                ## `con` - there is, however, `xpress_con` and `pyomo_con`
-                lb = con.lb
-                ub = con.ub
+                lb = xpress_con.lb
+                ub = xpress_con.ub
                 ub_s = val
                 expr_val = ub - ub_s
                 lb_s = lb - expr_val
diff --git a/pyomo/solvers/plugins/solvers/xpress_persistent.py b/pyomo/solvers/plugins/solvers/xpress_persistent.py
index 56024bc0540..fbdc2866dcf 100644
--- a/pyomo/solvers/plugins/solvers/xpress_persistent.py
+++ b/pyomo/solvers/plugins/solvers/xpress_persistent.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -90,7 +90,7 @@ def update_var(self, var):
 
         Parameters
         ----------
-        var: Var (scalar Var or single _VarData)
+        var: Var (scalar Var or single VarData)
 
         """
         # see PR #366 for discussion about handling indexed
@@ -124,7 +124,7 @@ def _add_column(self, var, obj_coef, constraints, coefficients):
 
         Parameters
         ----------
-        var: Var (scalar Var or single _VarData)
+        var: Var (scalar Var or single VarData)
         obj_coef: float
         constraints: list of solver constraints
         coefficients: list of coefficients to put on var in the associated constraint
diff --git a/pyomo/solvers/tests/__init__.py b/pyomo/solvers/tests/__init__.py
index 42c694b0170..4d8d45da724 100644
--- a/pyomo/solvers/tests/__init__.py
+++ b/pyomo/solvers/tests/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/checks/__init__.py b/pyomo/solvers/tests/checks/__init__.py
index 03a34303759..ccd3a0f98a4 100644
--- a/pyomo/solvers/tests/checks/__init__.py
+++ b/pyomo/solvers/tests/checks/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/checks/test_BARON.py b/pyomo/solvers/tests/checks/test_BARON.py
index 897f1e88a42..29c7ffb0148 100644
--- a/pyomo/solvers/tests/checks/test_BARON.py
+++ b/pyomo/solvers/tests/checks/test_BARON.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/checks/test_CBCplugin.py b/pyomo/solvers/tests/checks/test_CBCplugin.py
index fe01a89bb53..ad8846509ea 100644
--- a/pyomo/solvers/tests/checks/test_CBCplugin.py
+++ b/pyomo/solvers/tests/checks/test_CBCplugin.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -29,7 +29,7 @@
     maximize,
     minimize,
 )
-from pyomo.opt import SolverFactory, ProblemSense, TerminationCondition, SolverStatus
+from pyomo.opt import SolverFactory, TerminationCondition, SolverStatus
 from pyomo.solvers.plugins.solvers.CBCplugin import CBCSHELL
 
 cbc_available = SolverFactory('cbc', solver_io='lp').available(exception_flag=False)
@@ -62,7 +62,7 @@ def test_infeasible_lp(self):
 
         results = self.opt.solve(self.model)
 
-        self.assertEqual(ProblemSense.minimize, results.problem.sense)
+        self.assertEqual(minimize, results.problem.sense)
         self.assertEqual(
             TerminationCondition.infeasible, results.solver.termination_condition
         )
@@ -81,7 +81,7 @@ def test_unbounded_lp(self):
 
         results = self.opt.solve(self.model)
 
-        self.assertEqual(ProblemSense.maximize, results.problem.sense)
+        self.assertEqual(maximize, results.problem.sense)
         self.assertEqual(
             TerminationCondition.unbounded, results.solver.termination_condition
         )
@@ -99,7 +99,7 @@ def test_optimal_lp(self):
 
         self.assertEqual(0.0, results.problem.lower_bound)
         self.assertEqual(0.0, results.problem.upper_bound)
-        self.assertEqual(ProblemSense.minimize, results.problem.sense)
+        self.assertEqual(minimize, results.problem.sense)
         self.assertEqual(
             TerminationCondition.optimal, results.solver.termination_condition
         )
@@ -118,7 +118,7 @@ def test_infeasible_mip(self):
 
         results = self.opt.solve(self.model)
 
-        self.assertEqual(ProblemSense.minimize, results.problem.sense)
+        self.assertEqual(minimize, results.problem.sense)
         self.assertEqual(
             TerminationCondition.infeasible, results.solver.termination_condition
         )
@@ -134,7 +134,7 @@ def test_unbounded_mip(self):
 
         results = self.opt.solve(self.model)
 
-        self.assertEqual(ProblemSense.minimize, results.problem.sense)
+        self.assertEqual(minimize, results.problem.sense)
         self.assertEqual(
             TerminationCondition.unbounded, results.solver.termination_condition
         )
@@ -159,7 +159,7 @@ def test_optimal_mip(self):
         self.assertEqual(1.0, results.problem.upper_bound)
         self.assertEqual(results.problem.number_of_binary_variables, 2)
         self.assertEqual(results.problem.number_of_integer_variables, 4)
-        self.assertEqual(ProblemSense.maximize, results.problem.sense)
+        self.assertEqual(maximize, results.problem.sense)
         self.assertEqual(
             TerminationCondition.optimal, results.solver.termination_condition
         )
diff --git a/pyomo/solvers/tests/checks/test_CPLEXDirect.py b/pyomo/solvers/tests/checks/test_CPLEXDirect.py
index 86e03d1024f..400d7ee5f75 100644
--- a/pyomo/solvers/tests/checks/test_CPLEXDirect.py
+++ b/pyomo/solvers/tests/checks/test_CPLEXDirect.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/checks/test_CPLEXPersistent.py b/pyomo/solvers/tests/checks/test_CPLEXPersistent.py
index d7f00d0f486..442212d4fbb 100644
--- a/pyomo/solvers/tests/checks/test_CPLEXPersistent.py
+++ b/pyomo/solvers/tests/checks/test_CPLEXPersistent.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -101,7 +101,7 @@ def test_add_column_exceptions(self):
 
         # add indexed constraint
         self.assertRaises(AttributeError, opt.add_column, m, m.y, -2, [m.ci], [1])
-        # add something not a _ConstraintData
+        # add something not a ConstraintData
         self.assertRaises(AttributeError, opt.add_column, m, m.y, -2, [m.x], [1])
 
         # constraint not on solver model
diff --git a/pyomo/solvers/tests/checks/test_GAMS.py b/pyomo/solvers/tests/checks/test_GAMS.py
index 7aa952a6c69..1eef09819f7 100644
--- a/pyomo/solvers/tests/checks/test_GAMS.py
+++ b/pyomo/solvers/tests/checks/test_GAMS.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/checks/test_MOSEKDirect.py b/pyomo/solvers/tests/checks/test_MOSEKDirect.py
index 369cc08161a..2cf7034b80a 100644
--- a/pyomo/solvers/tests/checks/test_MOSEKDirect.py
+++ b/pyomo/solvers/tests/checks/test_MOSEKDirect.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/checks/test_MOSEKPersistent.py b/pyomo/solvers/tests/checks/test_MOSEKPersistent.py
index 59ea930c4f0..a4c0aa21666 100644
--- a/pyomo/solvers/tests/checks/test_MOSEKPersistent.py
+++ b/pyomo/solvers/tests/checks/test_MOSEKPersistent.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.common.unittest as unittest
 
 from pyomo.opt import (
diff --git a/pyomo/solvers/tests/checks/test_SAS.py b/pyomo/solvers/tests/checks/test_SAS.py
new file mode 100644
index 00000000000..6dd662bdb21
--- /dev/null
+++ b/pyomo/solvers/tests/checks/test_SAS.py
@@ -0,0 +1,543 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import os
+import pyomo.common.unittest as unittest
+from unittest import mock
+from pyomo.environ import (
+    ConcreteModel,
+    Var,
+    Objective,
+    Constraint,
+    NonNegativeIntegers,
+    NonNegativeReals,
+    Reals,
+    Integers,
+    maximize,
+    minimize,
+    Suffix,
+)
+from pyomo.opt.results import SolverStatus, TerminationCondition, ProblemSense
+from pyomo.opt import SolverFactory, check_available_solvers
+import warnings
+
+CFGFILE = os.environ.get("SAS_CFG_FILE_PATH", None)
+
+CAS_OPTIONS = {
+    "hostname": os.environ.get("CASHOST", None),
+    "port": os.environ.get("CASPORT", None),
+    "authinfo": os.environ.get("CASAUTHINFO", None),
+}
+
+
+sas_available = check_available_solvers("sas")
+
+
+class SASTestAbc:
+    solver_io = "_sas94"
+    session_options = {}
+    cfgfile = CFGFILE
+
+    @classmethod
+    def setUpClass(cls):
+        cls.opt_sas = SolverFactory(
+            "sas", solver_io=cls.solver_io, cfgfile=cls.cfgfile, **cls.session_options
+        )
+
+    @classmethod
+    def tearDownClass(cls):
+        del cls.opt_sas
+
+    def setObj(self):
+        X = self.instance.X
+        self.instance.Obj = Objective(
+            expr=2 * X[1] - 3 * X[2] - 4 * X[3], sense=minimize
+        )
+
+    def setX(self):
+        self.instance.X = Var([1, 2, 3], within=NonNegativeReals)
+
+    def setUp(self):
+        # Disable resource warnings
+        warnings.filterwarnings("ignore", category=ResourceWarning)
+        instance = self.instance = ConcreteModel()
+        self.setX()
+        X = instance.X
+        instance.R1 = Constraint(expr=-2 * X[2] - 3 * X[3] >= -5)
+        instance.R2 = Constraint(expr=X[1] + X[2] + 2 * X[3] <= 4)
+        instance.R3 = Constraint(expr=X[1] + 2 * X[2] + 3 * X[3] <= 7)
+        self.setObj()
+
+        # Declare suffixes for solution information
+        instance.status = Suffix(direction=Suffix.IMPORT)
+        instance.slack = Suffix(direction=Suffix.IMPORT)
+        instance.rc = Suffix(direction=Suffix.IMPORT)
+        instance.dual = Suffix(direction=Suffix.IMPORT)
+
+    def tearDown(self):
+        del self.instance
+
+    def run_solver(self, **kwargs):
+        opt_sas = self.opt_sas
+        instance = self.instance
+
+        # Call the solver
+        self.results = opt_sas.solve(instance, **kwargs)
+
+
+class SASTestLP(SASTestAbc):
+    def checkSolution(self):
+        instance = self.instance
+        results = self.results
+        # Get the objective sense, we use the same code for minimization and maximization tests
+        sense = instance.Obj.sense
+
+        # Check status
+        self.assertEqual(results.solver.status, SolverStatus.ok)
+        self.assertEqual(
+            results.solver.termination_condition, TerminationCondition.optimal
+        )
+
+        # Check objective value
+        self.assertAlmostEqual(instance.Obj(), sense * -7.5)
+
+        # Check primal solution values
+        self.assertAlmostEqual(instance.X[1].value, 0.0)
+        self.assertAlmostEqual(instance.X[2].value, 2.5)
+        self.assertAlmostEqual(instance.X[3].value, 0.0)
+
+        # Check reduced cost
+        self.assertAlmostEqual(instance.rc[instance.X[1]], sense * 2.0)
+        self.assertAlmostEqual(instance.rc[instance.X[2]], sense * 0.0)
+        self.assertAlmostEqual(instance.rc[instance.X[3]], sense * 0.5)
+
+        # Check slack
+        self.assertAlmostEqual(instance.slack[instance.R1], -5.0)
+        self.assertAlmostEqual(instance.slack[instance.R2], 2.5)
+        self.assertAlmostEqual(instance.slack[instance.R3], 5.0)
+
+        # Check dual solution
+        self.assertAlmostEqual(instance.dual[instance.R1], sense * 1.5)
+        self.assertAlmostEqual(instance.dual[instance.R2], sense * 0.0)
+        self.assertAlmostEqual(instance.dual[instance.R3], sense * 0.0)
+
+        # Check basis status
+        self.assertEqual(instance.status[instance.X[1]], "L")
+        self.assertEqual(instance.status[instance.X[2]], "B")
+        self.assertEqual(instance.status[instance.X[3]], "L")
+        self.assertEqual(instance.status[instance.R1], "U")
+        self.assertEqual(instance.status[instance.R2], "B")
+        self.assertEqual(instance.status[instance.R3], "B")
+
+    def test_solver_default(self):
+        self.run_solver()
+        self.checkSolution()
+
+    def test_solver_tee(self):
+        self.run_solver(tee=True)
+        self.checkSolution()
+
+    def test_solver_primal(self):
+        self.run_solver(options={"algorithm": "ps"})
+        self.assertIn("NOTE: The Primal Simplex algorithm is used.", self.opt_sas._log)
+        self.checkSolution()
+
+    def test_solver_ipm(self):
+        self.run_solver(options={"algorithm": "ip"})
+        self.assertIn("NOTE: The Interior Point algorithm is used.", self.opt_sas._log)
+        self.checkSolution()
+
+    def test_solver_intoption(self):
+        self.run_solver(options={"maxiter": 20})
+        self.checkSolution()
+
+    def test_solver_invalidoption(self):
+        with self.assertRaisesRegex(ValueError, "syntax error"):
+            self.run_solver(options={"foo": "bar"})
+
+    def test_solver_max(self):
+        X = self.instance.X
+        self.instance.Obj.set_value(expr=-2 * X[1] + 3 * X[2] + 4 * X[3])
+        self.instance.Obj.sense = maximize
+        self.run_solver()
+        self.checkSolution()
+        self.assertEqual(self.results.problem.sense, ProblemSense.maximize)
+
+    def test_solver_infeasible(self):
+        instance = self.instance
+        X = instance.X
+        instance.R4 = Constraint(expr=-2 * X[2] - 3 * X[3] <= -6)
+        self.run_solver()
+        results = self.results
+        self.assertEqual(results.solver.status, SolverStatus.warning)
+        self.assertEqual(
+            results.solver.termination_condition, TerminationCondition.infeasible
+        )
+        self.assertEqual(results.solver.message, "The problem is infeasible.")
+
+    def test_solver_infeasible_or_unbounded(self):
+        self.instance.X.domain = Reals
+        self.run_solver()
+        results = self.results
+        self.assertEqual(results.solver.status, SolverStatus.warning)
+        self.assertIn(
+            results.solver.termination_condition,
+            [
+                TerminationCondition.infeasibleOrUnbounded,
+                TerminationCondition.unbounded,
+            ],
+        )
+        self.assertIn(
+            results.solver.message,
+            ["The problem is infeasible or unbounded.", "The problem is unbounded."],
+        )
+
+    def test_solver_unbounded(self):
+        self.instance.X.domain = Reals
+        self.run_solver(options={"presolver": "none", "algorithm": "primal"})
+        results = self.results
+        self.assertEqual(results.solver.status, SolverStatus.warning)
+        self.assertEqual(
+            results.solver.termination_condition, TerminationCondition.unbounded
+        )
+        self.assertEqual(results.solver.message, "The problem is unbounded.")
+
+    def checkSolutionDecomp(self):
+        instance = self.instance
+        results = self.results
+        # Get the objective sense, we use the same code for minimization and maximization tests
+        sense = instance.Obj.sense
+
+        # Check status
+        self.assertEqual(results.solver.status, SolverStatus.ok)
+        self.assertEqual(
+            results.solver.termination_condition, TerminationCondition.optimal
+        )
+
+        # Check objective value
+        self.assertAlmostEqual(instance.Obj(), sense * -7.5)
+
+        # Check primal solution values
+        self.assertAlmostEqual(instance.X[1].value, 0.0)
+        self.assertAlmostEqual(instance.X[2].value, 2.5)
+        self.assertAlmostEqual(instance.X[3].value, 0.0)
+
+        # Check reduced cost
+        self.assertAlmostEqual(instance.rc[instance.X[1]], sense * 2.0)
+        self.assertAlmostEqual(instance.rc[instance.X[2]], sense * 0.0)
+        self.assertAlmostEqual(instance.rc[instance.X[3]], sense * 0.5)
+
+        # Check slack
+        self.assertAlmostEqual(instance.slack[instance.R1], -5.0)
+        self.assertAlmostEqual(instance.slack[instance.R2], 2.5)
+        self.assertAlmostEqual(instance.slack[instance.R3], 5.0)
+
+        # Check dual solution
+        self.assertAlmostEqual(instance.dual[instance.R1], sense * 1.5)
+        self.assertAlmostEqual(instance.dual[instance.R2], sense * 0.0)
+        self.assertAlmostEqual(instance.dual[instance.R3], sense * 0.0)
+
+        # Don't check basis status for decomp
+
+    def test_solver_decomp(self):
+        self.run_solver(
+            options={
+                "decomp": {"absobjgap": 0.0},
+                "decompmaster": {"algorithm": "dual"},
+                "decompsubprob": {"presolver": "none"},
+            }
+        )
+        self.assertIn(
+            "NOTE: The DECOMP method value DEFAULT is applied.", self.opt_sas._log
+        )
+        self.checkSolutionDecomp()
+
+    def test_solver_iis(self):
+        self.run_solver(options={"iis": "true"})
+        results = self.results
+        self.assertEqual(results.solver.status, SolverStatus.ok)
+        self.assertEqual(
+            results.solver.termination_condition, TerminationCondition.feasible
+        )
+        self.assertIn("NOTE: The IIS= option is enabled.", self.opt_sas._log)
+        self.assertEqual(
+            results.solver.message,
+            "The problem is feasible. This status is displayed when the IIS=TRUE option is specified and the problem is feasible.",
+        )
+
+    def test_solver_maxiter(self):
+        self.run_solver(options={"maxiter": 1})
+        results = self.results
+        self.assertEqual(results.solver.status, SolverStatus.ok)
+        self.assertEqual(
+            results.solver.termination_condition, TerminationCondition.maxIterations
+        )
+        self.assertEqual(
+            results.solver.message,
+            "The maximum allowable number of iterations was reached.",
+        )
+
+    def test_solver_with_milp(self):
+        self.run_solver(options={"with": "milp"})
+        self.assertIn(
+            "WARNING: The problem has no integer variables.", self.opt_sas._log
+        )
+
+
+@unittest.skipIf(not sas_available, "The SAS solver is not available")
+class SASTestLP94(SASTestLP, unittest.TestCase):
+    @mock.patch(
+        "pyomo.solvers.plugins.solvers.SAS.SAS94.sas_version",
+        return_value="9.sd45s39M4234232",
+    )
+    def test_solver_versionM4(self, sas):
+        with self.assertRaises(NotImplementedError):
+            self.run_solver()
+
+    @mock.patch(
+        "pyomo.solvers.plugins.solvers.SAS.SAS94.sas_version",
+        return_value="9.34897293M5324u98",
+    )
+    def test_solver_versionM5(self, sas):
+        self.run_solver()
+        self.checkSolution()
+
+    @mock.patch("saspy.SASsession.submit", return_value={"LOG": "", "LST": ""})
+    @mock.patch("saspy.SASsession.symget", return_value="STATUS=OUT_OF_MEMORY")
+    def test_solver_out_of_memory(self, submit_mock, symget_mocks):
+        self.run_solver(load_solutions=False)
+        results = self.results
+        self.assertEqual(results.solver.status, SolverStatus.aborted)
+
+    @mock.patch("saspy.SASsession.submit", return_value={"LOG": "", "LST": ""})
+    @mock.patch("saspy.SASsession.symget", return_value="STATUS=ERROR")
+    def test_solver_error(self, submit_mock, symget_mock):
+        self.run_solver(load_solutions=False)
+        results = self.results
+        self.assertEqual(results.solver.status, SolverStatus.error)
+
+
+# @unittest.skipIf(not sas_available, "The SAS solver is not available")
+@unittest.skip("Tests not yet configured for SAS Viya interface.")
+class SASTestLPCAS(SASTestLP, unittest.TestCase):
+    solver_io = "_sascas"
+    session_options = CAS_OPTIONS
+
+    @mock.patch("pyomo.solvers.plugins.solvers.SAS.stat")
+    def test_solver_large_file(self, os_stat):
+        os_stat.return_value.st_size = 3 * 1024**3
+        self.run_solver()
+        self.checkSolution()
+
+
+class SASTestMILP(SASTestAbc):
+    def setX(self):
+        self.instance.X = Var([1, 2, 3], within=NonNegativeIntegers)
+
+    def checkSolution(self):
+        instance = self.instance
+        results = self.results
+
+        # Get the objective sense, we use the same code for minimization and maximization tests
+        sense = instance.Obj.sense
+
+        # Check status
+        self.assertEqual(results.solver.status, SolverStatus.ok)
+        self.assertEqual(
+            results.solver.termination_condition, TerminationCondition.optimal
+        )
+
+        # Check objective value
+        self.assertAlmostEqual(instance.Obj(), sense * -7)
+
+        # Check primal solution values
+        self.assertAlmostEqual(instance.X[1].value, 0.0)
+        self.assertAlmostEqual(instance.X[2].value, 1.0)
+        self.assertAlmostEqual(instance.X[3].value, 1.0)
+
+    def test_solver_default(self):
+        self.run_solver()
+        self.checkSolution()
+
+    def test_solver_tee(self):
+        self.run_solver(tee=True)
+        self.checkSolution()
+
+    def test_solver_presolve(self):
+        self.run_solver(options={"presolver": "none"})
+        self.assertIn(
+            "NOTE: The MILP presolver value NONE is applied.", self.opt_sas._log
+        )
+        self.checkSolution()
+
+    def test_solver_intoption(self):
+        self.run_solver(options={"maxnodes": 20})
+        self.checkSolution()
+
+    def test_solver_invalidoption(self):
+        with self.assertRaisesRegex(ValueError, "syntax error"):
+            self.run_solver(options={"foo": "bar"})
+
+    def test_solver_max(self):
+        X = self.instance.X
+        self.instance.Obj.set_value(expr=-2 * X[1] + 3 * X[2] + 4 * X[3])
+        self.instance.Obj.sense = maximize
+        self.run_solver()
+        self.checkSolution()
+
+    def test_solver_infeasible(self):
+        instance = self.instance
+        X = instance.X
+        instance.R4 = Constraint(expr=-2 * X[2] - 3 * X[3] <= -6)
+        self.run_solver()
+        results = self.results
+        self.assertEqual(results.solver.status, SolverStatus.warning)
+        self.assertEqual(
+            results.solver.termination_condition, TerminationCondition.infeasible
+        )
+        self.assertEqual(results.solver.message, "The problem is infeasible.")
+
+    def test_solver_infeasible_or_unbounded(self):
+        self.instance.X.domain = Integers
+        self.run_solver()
+        results = self.results
+        self.assertEqual(results.solver.status, SolverStatus.warning)
+        self.assertIn(
+            results.solver.termination_condition,
+            [
+                TerminationCondition.infeasibleOrUnbounded,
+                TerminationCondition.unbounded,
+            ],
+        )
+        self.assertIn(
+            results.solver.message,
+            ["The problem is infeasible or unbounded.", "The problem is unbounded."],
+        )
+
+    def test_solver_unbounded(self):
+        self.instance.X.domain = Integers
+        self.run_solver(
+            options={"presolver": "none", "rootnode": {"algorithm": "primal"}}
+        )
+        results = self.results
+        self.assertEqual(results.solver.status, SolverStatus.warning)
+        self.assertEqual(
+            results.solver.termination_condition, TerminationCondition.unbounded
+        )
+        self.assertEqual(results.solver.message, "The problem is unbounded.")
+
+    def test_solver_decomp(self):
+        self.run_solver(
+            options={
+                "decomp": {"hybrid": "off"},
+                "decompmaster": {"algorithm": "dual"},
+                "decompmasterip": {"presolver": "none"},
+                "decompsubprob": {"presolver": "none"},
+            }
+        )
+        self.assertIn(
+            "NOTE: The DECOMP method value DEFAULT is applied.", self.opt_sas._log
+        )
+        self.checkSolution()
+
+    def test_solver_rootnode(self):
+        self.run_solver(options={"rootnode": {"presolver": "automatic"}})
+        self.checkSolution()
+
+    def test_solver_maxnodes(self):
+        self.run_solver(options={"maxnodes": 0})
+        results = self.results
+        self.assertEqual(results.solver.status, SolverStatus.ok)
+        self.assertEqual(
+            results.solver.termination_condition, TerminationCondition.maxEvaluations
+        )
+        self.assertEqual(
+            results.solver.message,
+            "The solver reached the maximum number of nodes specified by the MAXNODES= option and found a solution.",
+        )
+
+    def test_solver_maxsols(self):
+        self.run_solver(options={"maxsols": 1})
+        results = self.results
+        self.assertEqual(results.solver.status, SolverStatus.ok)
+        self.assertEqual(
+            results.solver.termination_condition, TerminationCondition.maxEvaluations
+        )
+        self.assertEqual(
+            results.solver.message,
+            "The solver reached the maximum number of solutions specified by the MAXSOLS= option.",
+        )
+
+    def test_solver_target(self):
+        self.run_solver(options={"target": -6.0})
+        results = self.results
+        self.assertEqual(results.solver.status, SolverStatus.ok)
+        self.assertEqual(
+            results.solver.termination_condition, TerminationCondition.optimal
+        )
+        self.assertEqual(
+            results.solver.message,
+            "The solution is not worse than the target specified by the TARGET= option.",
+        )
+
+    def test_solver_primalin(self):
+        X = self.instance.X
+        X[1] = None
+        X[2] = 3
+        X[3] = 7
+        self.run_solver(warmstart=True)
+        self.checkSolution()
+        self.assertIn(
+            "NOTE: The input solution is infeasible or incomplete. Repair heuristics are applied.",
+            self.opt_sas._log,
+        )
+
+    def test_solver_primalin_nosol(self):
+        X = self.instance.X
+        X[1] = None
+        X[2] = None
+        X[3] = None
+        self.run_solver(warmstart=True)
+        self.checkSolution()
+
+    @mock.patch("pyomo.solvers.plugins.solvers.SAS.stat")
+    def test_solver_large_file(self, os_stat):
+        os_stat.return_value.st_size = 3 * 1024**3
+        self.run_solver()
+        self.checkSolution()
+
+    def test_solver_with_lp(self):
+        self.run_solver(options={"with": "lp"})
+        self.assertIn(
+            "contains integer variables; the linear relaxation will be solved.",
+            self.opt_sas._log,
+        )
+
+    def test_solver_warmstart_capable(self):
+        self.run_solver()
+        self.assertTrue(self.opt_sas.warm_start_capable())
+
+
+# @unittest.skipIf(not sas_available, "The SAS solver is not available")
+@unittest.skip("MILP94 tests disabled.")
+class SASTestMILP94(SASTestMILP, unittest.TestCase):
+    pass
+
+
+# @unittest.skipIf(not sas_available, "The SAS solver is not available")
+@unittest.skip("Tests not yet configured for SAS Viya interface.")
+class SASTestMILPCAS(SASTestMILP, unittest.TestCase):
+    solver_io = "_sascas"
+    session_options = CAS_OPTIONS
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/pyomo/solvers/tests/checks/test_amplfunc_merge.py b/pyomo/solvers/tests/checks/test_amplfunc_merge.py
new file mode 100644
index 00000000000..2c819404d2f
--- /dev/null
+++ b/pyomo/solvers/tests/checks/test_amplfunc_merge.py
@@ -0,0 +1,162 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+import pyomo.common.unittest as unittest
+from pyomo.solvers.amplfunc_merge import amplfunc_string_merge, amplfunc_merge
+
+
+class TestAMPLFUNCStringMerge(unittest.TestCase):
+    def test_merge_no_dup(self):
+        s1 = "my/place/l1.so\nanother/place/l1.so"
+        s2 = "my/place/l2.so"
+        sm = amplfunc_string_merge(s1, s2)
+        sm_list = sm.split("\n")
+        self.assertEqual(len(sm_list), 3)
+        # The order of lines should be maintained with the second string
+        # following the first
+        self.assertEqual(sm_list[0], "my/place/l1.so")
+        self.assertEqual(sm_list[1], "another/place/l1.so")
+        self.assertEqual(sm_list[2], "my/place/l2.so")
+
+    def test_merge_empty1(self):
+        s1 = ""
+        s2 = "my/place/l2.so"
+        sm = amplfunc_string_merge(s1, s2)
+        sm_list = sm.split("\n")
+        self.assertEqual(len(sm_list), 1)
+        self.assertEqual(sm_list[0], "my/place/l2.so")
+
+    def test_merge_empty2(self):
+        s1 = "my/place/l2.so"
+        s2 = ""
+        sm = amplfunc_string_merge(s1, s2)
+        sm_list = sm.split("\n")
+        self.assertEqual(len(sm_list), 1)
+        self.assertEqual(sm_list[0], "my/place/l2.so")
+
+    def test_merge_empty_both(self):
+        s1 = ""
+        s2 = ""
+        sm = amplfunc_string_merge(s1, s2)
+        sm_list = sm.split("\n")
+        self.assertEqual(len(sm_list), 1)
+        self.assertEqual(sm_list[0], "")
+
+    def test_merge_bad_type(self):
+        self.assertRaises(AttributeError, amplfunc_string_merge, "", 3)
+        self.assertRaises(AttributeError, amplfunc_string_merge, 3, "")
+        self.assertRaises(AttributeError, amplfunc_string_merge, 3, 3)
+        self.assertRaises(AttributeError, amplfunc_string_merge, None, "")
+        self.assertRaises(AttributeError, amplfunc_string_merge, "", None)
+        self.assertRaises(AttributeError, amplfunc_string_merge, 2.3, "")
+        self.assertRaises(AttributeError, amplfunc_string_merge, "", 2.3)
+
+    def test_merge_duplicate1(self):
+        s1 = "my/place/l1.so\nanother/place/l1.so"
+        s2 = "my/place/l1.so\nanother/place/l1.so"
+        sm = amplfunc_string_merge(s1, s2)
+        sm_list = sm.split("\n")
+        self.assertEqual(len(sm_list), 2)
+        # The order of lines should be maintained with the second string
+        # following the first
+        self.assertEqual(sm_list[0], "my/place/l1.so")
+        self.assertEqual(sm_list[1], "another/place/l1.so")
+
+    def test_merge_duplicate2(self):
+        s1 = "my/place/l1.so\nanother/place/l1.so"
+        s2 = "my/place/l1.so"
+        sm = amplfunc_string_merge(s1, s2)
+        sm_list = sm.split("\n")
+        self.assertEqual(len(sm_list), 2)
+        # The order of lines should be maintained with the second string
+        # following the first
+        self.assertEqual(sm_list[0], "my/place/l1.so")
+        self.assertEqual(sm_list[1], "another/place/l1.so")
+
+    def test_merge_extra_linebreaks(self):
+        s1 = "\nmy/place/l1.so\nanother/place/l1.so\n"
+        s2 = "\nmy/place/l1.so\n\n"
+        sm = amplfunc_string_merge(s1, s2)
+        sm_list = sm.split("\n")
+        self.assertEqual(len(sm_list), 2)
+        # The order of lines should be maintained with the second string
+        # following the first
+        self.assertEqual(sm_list[0], "my/place/l1.so")
+        self.assertEqual(sm_list[1], "another/place/l1.so")
+
+
+class TestAMPLFUNCMerge(unittest.TestCase):
+    def test_merge_no_dup(self):
+        env = {
+            "AMPLFUNC": "my/place/l1.so\nanother/place/l1.so",
+            "PYOMO_AMPLFUNC": "my/place/l2.so",
+        }
+        sm = amplfunc_merge(env)
+        sm_list = sm.split("\n")
+        self.assertEqual(len(sm_list), 3)
+        self.assertEqual(sm_list[0], "my/place/l1.so")
+        self.assertEqual(sm_list[1], "another/place/l1.so")
+        self.assertEqual(sm_list[2], "my/place/l2.so")
+
+    def test_merge_empty1(self):
+        env = {"AMPLFUNC": "", "PYOMO_AMPLFUNC": "my/place/l2.so"}
+        sm = amplfunc_merge(env)
+        sm_list = sm.split("\n")
+        self.assertEqual(len(sm_list), 1)
+        self.assertEqual(sm_list[0], "my/place/l2.so")
+
+    def test_merge_empty2(self):
+        env = {"AMPLFUNC": "my/place/l2.so", "PYOMO_AMPLFUNC": ""}
+        sm = amplfunc_merge(env)
+        sm_list = sm.split("\n")
+        self.assertEqual(len(sm_list), 1)
+        self.assertEqual(sm_list[0], "my/place/l2.so")
+
+    def test_merge_empty_both(self):
+        env = {"AMPLFUNC": "", "PYOMO_AMPLFUNC": ""}
+        sm = amplfunc_merge(env)
+        sm_list = sm.split("\n")
+        self.assertEqual(len(sm_list), 1)
+        self.assertEqual(sm_list[0], "")
+
+    def test_merge_duplicate1(self):
+        env = {
+            "AMPLFUNC": "my/place/l1.so\nanother/place/l1.so",
+            "PYOMO_AMPLFUNC": "my/place/l1.so\nanother/place/l1.so",
+        }
+        sm = amplfunc_merge(env)
+        sm_list = sm.split("\n")
+        self.assertEqual(len(sm_list), 2)
+        self.assertEqual(sm_list[0], "my/place/l1.so")
+        self.assertEqual(sm_list[1], "another/place/l1.so")
+
+    def test_merge_no_pyomo(self):
+        env = {"AMPLFUNC": "my/place/l1.so\nanother/place/l1.so"}
+        sm = amplfunc_merge(env)
+        sm_list = sm.split("\n")
+        self.assertEqual(len(sm_list), 2)
+        self.assertEqual(sm_list[0], "my/place/l1.so")
+        self.assertEqual(sm_list[1], "another/place/l1.so")
+
+    def test_merge_no_user(self):
+        env = {"PYOMO_AMPLFUNC": "my/place/l1.so\nanother/place/l1.so"}
+        sm = amplfunc_merge(env)
+        sm_list = sm.split("\n")
+        self.assertEqual(len(sm_list), 2)
+        self.assertEqual(sm_list[0], "my/place/l1.so")
+        self.assertEqual(sm_list[1], "another/place/l1.so")
+
+    def test_merge_nothing(self):
+        env = {}
+        sm = amplfunc_merge(env)
+        sm_list = sm.split("\n")
+        self.assertEqual(len(sm_list), 1)
+        self.assertEqual(sm_list[0], "")
diff --git a/pyomo/solvers/tests/checks/test_cbc.py b/pyomo/solvers/tests/checks/test_cbc.py
index 0fd6e9f49a1..420de7cc61d 100644
--- a/pyomo/solvers/tests/checks/test_cbc.py
+++ b/pyomo/solvers/tests/checks/test_cbc.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/checks/test_cplex.py b/pyomo/solvers/tests/checks/test_cplex.py
index 44b82d2ad77..ff5ac5f17e1 100644
--- a/pyomo/solvers/tests/checks/test_cplex.py
+++ b/pyomo/solvers/tests/checks/test_cplex.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/checks/test_gurobi.py b/pyomo/solvers/tests/checks/test_gurobi.py
index f33a00ce8a2..e87685a046c 100644
--- a/pyomo/solvers/tests/checks/test_gurobi.py
+++ b/pyomo/solvers/tests/checks/test_gurobi.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.common.unittest as unittest
 from unittest.mock import patch, MagicMock
 
diff --git a/pyomo/solvers/tests/checks/test_gurobi_direct.py b/pyomo/solvers/tests/checks/test_gurobi_direct.py
index 7c60b207a9f..1e3a366a37a 100644
--- a/pyomo/solvers/tests/checks/test_gurobi_direct.py
+++ b/pyomo/solvers/tests/checks/test_gurobi_direct.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 """
 Tests for working with Gurobi environments. Some require a single-use license
 and are skipped if this isn't the case.
diff --git a/pyomo/solvers/tests/checks/test_gurobi_persistent.py b/pyomo/solvers/tests/checks/test_gurobi_persistent.py
index 9d69c1dd920..812390c23a4 100644
--- a/pyomo/solvers/tests/checks/test_gurobi_persistent.py
+++ b/pyomo/solvers/tests/checks/test_gurobi_persistent.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -382,7 +382,7 @@ def test_add_column_exceptions(self):
 
         # add indexed constraint
         self.assertRaises(AttributeError, opt.add_column, m, m.y, -2, [m.ci], [1])
-        # add something not a _ConstraintData
+        # add something not a ConstraintData
         self.assertRaises(AttributeError, opt.add_column, m, m.y, -2, [m.x], [1])
 
         # constraint not on solver model
diff --git a/pyomo/solvers/tests/checks/test_no_solution_behavior.py b/pyomo/solvers/tests/checks/test_no_solution_behavior.py
index 9ba8e86a013..81a2d2bf297 100644
--- a/pyomo/solvers/tests/checks/test_no_solution_behavior.py
+++ b/pyomo/solvers/tests/checks/test_no_solution_behavior.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/checks/test_pickle.py b/pyomo/solvers/tests/checks/test_pickle.py
index d8551b34740..745320cb4eb 100644
--- a/pyomo/solvers/tests/checks/test_pickle.py
+++ b/pyomo/solvers/tests/checks/test_pickle.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/checks/test_writers.py b/pyomo/solvers/tests/checks/test_writers.py
index e406e07a4d6..55002c71357 100644
--- a/pyomo/solvers/tests/checks/test_writers.py
+++ b/pyomo/solvers/tests/checks/test_writers.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/checks/test_xpress_persistent.py b/pyomo/solvers/tests/checks/test_xpress_persistent.py
index cd9c30fc73b..dcd36780f62 100644
--- a/pyomo/solvers/tests/checks/test_xpress_persistent.py
+++ b/pyomo/solvers/tests/checks/test_xpress_persistent.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 import pyomo.common.unittest as unittest
 import pyomo.environ as pe
 from pyomo.core.expr.taylor_series import taylor_series_expansion
@@ -251,7 +262,7 @@ def test_add_column_exceptions(self):
 
         # add indexed constraint
         self.assertRaises(AttributeError, opt.add_column, m, m.y, -2, [m.ci], [1])
-        # add something not a _ConstraintData
+        # add something not a ConstraintData
         self.assertRaises(AttributeError, opt.add_column, m, m.y, -2, [m.x], [1])
 
         # constraint not on solver model
diff --git a/pyomo/solvers/tests/mip/__init__.py b/pyomo/solvers/tests/mip/__init__.py
index c95d27d9497..707a8c4b7e5 100644
--- a/pyomo/solvers/tests/mip/__init__.py
+++ b/pyomo/solvers/tests/mip/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/mip/model.py b/pyomo/solvers/tests/mip/model.py
index 389151160b8..83c1411fe6c 100644
--- a/pyomo/solvers/tests/mip/model.py
+++ b/pyomo/solvers/tests/mip/model.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/mip/test_asl.py b/pyomo/solvers/tests/mip/test_asl.py
index 42b77df7d87..6f23a06eff2 100644
--- a/pyomo/solvers/tests/mip/test_asl.py
+++ b/pyomo/solvers/tests/mip/test_asl.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/mip/test_convert.py b/pyomo/solvers/tests/mip/test_convert.py
index cd916da29f2..962b021c4ae 100644
--- a/pyomo/solvers/tests/mip/test_convert.py
+++ b/pyomo/solvers/tests/mip/test_convert.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/mip/test_factory.py b/pyomo/solvers/tests/mip/test_factory.py
index 6960a0f8ced..31d47486aa4 100644
--- a/pyomo/solvers/tests/mip/test_factory.py
+++ b/pyomo/solvers/tests/mip/test_factory.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/mip/test_ipopt.py b/pyomo/solvers/tests/mip/test_ipopt.py
index bccb4f2a27c..38c3b35d8a1 100644
--- a/pyomo/solvers/tests/mip/test_ipopt.py
+++ b/pyomo/solvers/tests/mip/test_ipopt.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/mip/test_mip.py b/pyomo/solvers/tests/mip/test_mip.py
index 0257e65de20..58cdfe9f7de 100644
--- a/pyomo/solvers/tests/mip/test_mip.py
+++ b/pyomo/solvers/tests/mip/test_mip.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/mip/test_qp.py b/pyomo/solvers/tests/mip/test_qp.py
index 5d920b9085d..9c5cb5ffbc4 100644
--- a/pyomo/solvers/tests/mip/test_qp.py
+++ b/pyomo/solvers/tests/mip/test_qp.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/mip/test_scip.py b/pyomo/solvers/tests/mip/test_scip.py
index 7fffdc53c13..ad54daeddc0 100644
--- a/pyomo/solvers/tests/mip/test_scip.py
+++ b/pyomo/solvers/tests/mip/test_scip.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -106,6 +106,12 @@ def test_scip_solve_from_instance_options(self):
         results.write(filename=_out, times=False, format='json')
         self.compare_json(_out, join(currdir, "test_scip_solve_from_instance.baseline"))
 
+    def test_scip_solve_from_instance_with_reoptimization(self):
+        # Test scip with re-optimization option enabled
+        # This case changes the Scip output results which may break the results parser
+        self.scip.options['reoptimization/enable'] = True
+        self.test_scip_solve_from_instance()
+
 
 if __name__ == "__main__":
     deleteFiles = False
diff --git a/pyomo/solvers/tests/mip/test_scip_log_data.py b/pyomo/solvers/tests/mip/test_scip_log_data.py
index 8f756de220a..a0006d69eb7 100644
--- a/pyomo/solvers/tests/mip/test_scip_log_data.py
+++ b/pyomo/solvers/tests/mip/test_scip_log_data.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 #!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 """
diff --git a/pyomo/solvers/tests/mip/test_scip_solve_from_instance.baseline b/pyomo/solvers/tests/mip/test_scip_solve_from_instance.baseline
index a3eb9ffacec..976e4a1b82e 100644
--- a/pyomo/solvers/tests/mip/test_scip_solve_from_instance.baseline
+++ b/pyomo/solvers/tests/mip/test_scip_solve_from_instance.baseline
@@ -1,7 +1,7 @@
 {
     "Problem": [
         {
-            "Lower bound": -Infinity,
+            "Lower bound": 1.0,
             "Number of constraints": 0, 
             "Number of objectives": 1, 
             "Number of variables": 1, 
diff --git a/pyomo/solvers/tests/mip/test_scip_version.py b/pyomo/solvers/tests/mip/test_scip_version.py
index c0cc80c0316..f83bed2da32 100644
--- a/pyomo/solvers/tests/mip/test_scip_version.py
+++ b/pyomo/solvers/tests/mip/test_scip_version.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/mip/test_solver.py b/pyomo/solvers/tests/mip/test_solver.py
index 90a7076cbca..bf3550a001d 100644
--- a/pyomo/solvers/tests/mip/test_solver.py
+++ b/pyomo/solvers/tests/mip/test_solver.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/models/LP_block.py b/pyomo/solvers/tests/models/LP_block.py
index 64c866faa9e..37b01dc1c2d 100644
--- a/pyomo/solvers/tests/models/LP_block.py
+++ b/pyomo/solvers/tests/models/LP_block.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/models/LP_compiled.py b/pyomo/solvers/tests/models/LP_compiled.py
index 686406e7ec6..960b8730e0c 100644
--- a/pyomo/solvers/tests/models/LP_compiled.py
+++ b/pyomo/solvers/tests/models/LP_compiled.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/models/LP_constant_objective1.py b/pyomo/solvers/tests/models/LP_constant_objective1.py
index 306a7a867a2..0c01cd7085f 100644
--- a/pyomo/solvers/tests/models/LP_constant_objective1.py
+++ b/pyomo/solvers/tests/models/LP_constant_objective1.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/models/LP_constant_objective2.py b/pyomo/solvers/tests/models/LP_constant_objective2.py
index 17da01bf209..07739c1f708 100644
--- a/pyomo/solvers/tests/models/LP_constant_objective2.py
+++ b/pyomo/solvers/tests/models/LP_constant_objective2.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/models/LP_duals_maximize.py b/pyomo/solvers/tests/models/LP_duals_maximize.py
index 61d827daa62..ed45e4eee29 100644
--- a/pyomo/solvers/tests/models/LP_duals_maximize.py
+++ b/pyomo/solvers/tests/models/LP_duals_maximize.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/models/LP_duals_minimize.py b/pyomo/solvers/tests/models/LP_duals_minimize.py
index 77471d0182c..3f97276a61e 100644
--- a/pyomo/solvers/tests/models/LP_duals_minimize.py
+++ b/pyomo/solvers/tests/models/LP_duals_minimize.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/models/LP_inactive_index.py b/pyomo/solvers/tests/models/LP_inactive_index.py
index d3fdd5b32ca..5e2b570a1e8 100644
--- a/pyomo/solvers/tests/models/LP_inactive_index.py
+++ b/pyomo/solvers/tests/models/LP_inactive_index.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/models/LP_infeasible1.py b/pyomo/solvers/tests/models/LP_infeasible1.py
index 28243574a37..8cba441a6c3 100644
--- a/pyomo/solvers/tests/models/LP_infeasible1.py
+++ b/pyomo/solvers/tests/models/LP_infeasible1.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/models/LP_infeasible2.py b/pyomo/solvers/tests/models/LP_infeasible2.py
index 383267c0e3c..7f417d9145c 100644
--- a/pyomo/solvers/tests/models/LP_infeasible2.py
+++ b/pyomo/solvers/tests/models/LP_infeasible2.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/models/LP_piecewise.py b/pyomo/solvers/tests/models/LP_piecewise.py
index f6350b38591..22ee9d08694 100644
--- a/pyomo/solvers/tests/models/LP_piecewise.py
+++ b/pyomo/solvers/tests/models/LP_piecewise.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/models/LP_simple.py b/pyomo/solvers/tests/models/LP_simple.py
index 3449a657f79..4f1e6dcbc7e 100644
--- a/pyomo/solvers/tests/models/LP_simple.py
+++ b/pyomo/solvers/tests/models/LP_simple.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/models/LP_trivial_constraints.py b/pyomo/solvers/tests/models/LP_trivial_constraints.py
index 096c9e71712..3958f2b4493 100644
--- a/pyomo/solvers/tests/models/LP_trivial_constraints.py
+++ b/pyomo/solvers/tests/models/LP_trivial_constraints.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/models/LP_unbounded.py b/pyomo/solvers/tests/models/LP_unbounded.py
index e3173e2ff07..e75977c40ba 100644
--- a/pyomo/solvers/tests/models/LP_unbounded.py
+++ b/pyomo/solvers/tests/models/LP_unbounded.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/models/LP_unique_duals.py b/pyomo/solvers/tests/models/LP_unique_duals.py
index 624181eb27d..f5a4df6338d 100644
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diff --git a/pyomo/solvers/tests/models/LP_unused_vars.py b/pyomo/solvers/tests/models/LP_unused_vars.py
index 5e6b40fa4bf..0062fc58463 100644
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diff --git a/pyomo/solvers/tests/models/MILP_discrete_var_bounds.py b/pyomo/solvers/tests/models/MILP_discrete_var_bounds.py
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diff --git a/pyomo/solvers/tests/models/MILP_simple.py b/pyomo/solvers/tests/models/MILP_simple.py
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 #  Pyomo: Python Optimization Modeling Objects
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diff --git a/pyomo/solvers/tests/models/MIQP_simple.py b/pyomo/solvers/tests/models/MIQP_simple.py
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 #  Pyomo: Python Optimization Modeling Objects
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diff --git a/pyomo/solvers/tests/models/QCP_simple.py b/pyomo/solvers/tests/models/QCP_simple.py
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diff --git a/pyomo/solvers/tests/models/__init__.py b/pyomo/solvers/tests/models/__init__.py
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diff --git a/pyomo/solvers/tests/models/base.py b/pyomo/solvers/tests/models/base.py
index 106e8860145..25442611806 100644
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diff --git a/pyomo/solvers/tests/piecewise_linear/__init__.py b/pyomo/solvers/tests/piecewise_linear/__init__.py
index bcaa157f6f4..79b33f0d427 100644
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diff --git a/pyomo/solvers/tests/piecewise_linear/kernel_problems/concave_var.py b/pyomo/solvers/tests/piecewise_linear/kernel_problems/concave_var.py
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diff --git a/pyomo/solvers/tests/piecewise_linear/kernel_problems/convex_var.py b/pyomo/solvers/tests/piecewise_linear/kernel_problems/convex_var.py
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diff --git a/pyomo/solvers/tests/piecewise_linear/kernel_problems/piecewise_var.py b/pyomo/solvers/tests/piecewise_linear/kernel_problems/piecewise_var.py
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diff --git a/pyomo/solvers/tests/piecewise_linear/kernel_problems/step_var.py b/pyomo/solvers/tests/piecewise_linear/kernel_problems/step_var.py
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diff --git a/pyomo/solvers/tests/piecewise_linear/problems/concave_multi_vararray1.py b/pyomo/solvers/tests/piecewise_linear/problems/concave_multi_vararray1.py
index b24f7e1bd72..473b3328660 100644
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diff --git a/pyomo/solvers/tests/piecewise_linear/problems/concave_var.py b/pyomo/solvers/tests/piecewise_linear/problems/concave_var.py
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diff --git a/pyomo/solvers/tests/piecewise_linear/problems/concave_vararray.py b/pyomo/solvers/tests/piecewise_linear/problems/concave_vararray.py
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diff --git a/pyomo/solvers/tests/piecewise_linear/problems/convex_multi_vararray1.py b/pyomo/solvers/tests/piecewise_linear/problems/convex_multi_vararray1.py
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diff --git a/pyomo/solvers/tests/piecewise_linear/problems/convex_multi_vararray2.py b/pyomo/solvers/tests/piecewise_linear/problems/convex_multi_vararray2.py
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 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/piecewise_linear/problems/convex_var.py b/pyomo/solvers/tests/piecewise_linear/problems/convex_var.py
index bb4609be7c9..842ef50515b 100644
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 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/piecewise_linear/problems/convex_vararray.py b/pyomo/solvers/tests/piecewise_linear/problems/convex_vararray.py
index 140d69dcb1a..087d0977ee0 100644
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 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/piecewise_linear/problems/piecewise_multi_vararray.py b/pyomo/solvers/tests/piecewise_linear/problems/piecewise_multi_vararray.py
index 3c587d694e1..56452e0cd19 100644
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 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/piecewise_linear/problems/piecewise_var.py b/pyomo/solvers/tests/piecewise_linear/problems/piecewise_var.py
index 5b18842f81d..60c45a69e80 100644
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 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/piecewise_linear/problems/piecewise_vararray.py b/pyomo/solvers/tests/piecewise_linear/problems/piecewise_vararray.py
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 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/piecewise_linear/problems/step_var.py b/pyomo/solvers/tests/piecewise_linear/problems/step_var.py
index a0c1062c9d6..59cefdd39c9 100644
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 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/piecewise_linear/problems/step_vararray.py b/pyomo/solvers/tests/piecewise_linear/problems/step_vararray.py
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 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/piecewise_linear/problems/tester.py b/pyomo/solvers/tests/piecewise_linear/problems/tester.py
index 02e04f5052e..56261f7cc38 100644
--- a/pyomo/solvers/tests/piecewise_linear/problems/tester.py
+++ b/pyomo/solvers/tests/piecewise_linear/problems/tester.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/piecewise_linear/test_examples.py b/pyomo/solvers/tests/piecewise_linear/test_examples.py
index b151ffd2c0e..3454f62d56b 100644
--- a/pyomo/solvers/tests/piecewise_linear/test_examples.py
+++ b/pyomo/solvers/tests/piecewise_linear/test_examples.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/piecewise_linear/test_piecewise_linear.py b/pyomo/solvers/tests/piecewise_linear/test_piecewise_linear.py
index bfa206a987b..48472c2dabf 100644
--- a/pyomo/solvers/tests/piecewise_linear/test_piecewise_linear.py
+++ b/pyomo/solvers/tests/piecewise_linear/test_piecewise_linear.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/piecewise_linear/test_piecewise_linear_kernel.py b/pyomo/solvers/tests/piecewise_linear/test_piecewise_linear_kernel.py
index 4137d9d3eed..20addb2b1eb 100644
--- a/pyomo/solvers/tests/piecewise_linear/test_piecewise_linear_kernel.py
+++ b/pyomo/solvers/tests/piecewise_linear/test_piecewise_linear_kernel.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/tests/solvers.py b/pyomo/solvers/tests/solvers.py
index 6bbfe08c7c7..918a801ae37 100644
--- a/pyomo/solvers/tests/solvers.py
+++ b/pyomo/solvers/tests/solvers.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -9,8 +9,6 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-__all__ = ['test_solver_cases']
-
 import logging
 
 from pyomo.common.collections import Bunch
diff --git a/pyomo/solvers/tests/testcases.py b/pyomo/solvers/tests/testcases.py
index f5920ed6814..6bef40818d9 100644
--- a/pyomo/solvers/tests/testcases.py
+++ b/pyomo/solvers/tests/testcases.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/solvers/wrappers.py b/pyomo/solvers/wrappers.py
index 3b083f7a14f..ee167ce1cb0 100644
--- a/pyomo/solvers/wrappers.py
+++ b/pyomo/solvers/wrappers.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/util/__init__.py b/pyomo/util/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/util/__init__.py
+++ b/pyomo/util/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/util/blockutil.py b/pyomo/util/blockutil.py
index 52befea6ed5..9f043e64ab7 100644
--- a/pyomo/util/blockutil.py
+++ b/pyomo/util/blockutil.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -12,8 +12,6 @@
 # the purpose of this file is to collect all utility methods that compute
 # attributes of blocks, based on their contents.
 
-__all__ = ['has_discrete_variables']
-
 import logging
 
 from pyomo.core import Var, Constraint, TraversalStrategy
diff --git a/pyomo/util/calc_var_value.py b/pyomo/util/calc_var_value.py
index 42d38f2f874..42ee3119361 100644
--- a/pyomo/util/calc_var_value.py
+++ b/pyomo/util/calc_var_value.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -12,7 +12,7 @@
 from pyomo.common.errors import IterationLimitError
 from pyomo.common.numeric_types import native_numeric_types, native_complex_types, value
 from pyomo.core.expr.calculus.derivatives import differentiate
-from pyomo.core.base.constraint import Constraint, _ConstraintData
+from pyomo.core.base.constraint import Constraint
 
 import logging
 
@@ -53,9 +53,9 @@ def calculate_variable_from_constraint(
 
     Parameters:
     -----------
-    variable: :py:class:`_VarData`
+    variable: :py:class:`VarData`
         The variable to solve for
-    constraint: :py:class:`_ConstraintData` or relational expression or `tuple`
+    constraint: :py:class:`ConstraintData` or relational expression or `tuple`
         The equality constraint to use to solve for the variable value.
         May be a `ConstraintData` object or any valid argument for
         ``Constraint(expr=<>)`` (i.e., a relational expression or 2- or
@@ -81,10 +81,17 @@ def calculate_variable_from_constraint(
 
     """
     # Leverage all the Constraint logic to process the incoming tuple/expression
-    if not isinstance(constraint, _ConstraintData):
+    if not getattr(constraint, 'ctype', None) is Constraint:
         constraint = Constraint(expr=constraint, name=type(constraint).__name__)
         constraint.construct()
 
+    if constraint.is_indexed():
+        raise ValueError(
+            'calculate_variable_from_constraint(): constraint must be a '
+            'scalar constraint or a single ConstraintData.  Received '
+            f'{constraint.__class__.__name__} ("{constraint.name}")'
+        )
+
     body = constraint.body
     lower = constraint.lb
     upper = constraint.ub
diff --git a/pyomo/util/check_units.py b/pyomo/util/check_units.py
index be72493af3f..6f95486c8cd 100644
--- a/pyomo/util/check_units.py
+++ b/pyomo/util/check_units.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/util/components.py b/pyomo/util/components.py
index 02ef8a30f64..2f1d85a4934 100644
--- a/pyomo/util/components.py
+++ b/pyomo/util/components.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/util/diagnostics.py b/pyomo/util/diagnostics.py
index d4b7974b9da..709a483f2ff 100644
--- a/pyomo/util/diagnostics.py
+++ b/pyomo/util/diagnostics.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 # -*- coding: UTF-8 -*-
 """Module with miscellaneous diagnostic tools"""
 from pyomo.core.base.block import TraversalStrategy, Block
diff --git a/pyomo/util/infeasible.py b/pyomo/util/infeasible.py
index 9c8196d1ff4..961d5b35036 100644
--- a/pyomo/util/infeasible.py
+++ b/pyomo/util/infeasible.py
@@ -2,7 +2,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/util/model_size.py b/pyomo/util/model_size.py
index 9575e327a74..1fdac357368 100644
--- a/pyomo/util/model_size.py
+++ b/pyomo/util/model_size.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/util/report_scaling.py b/pyomo/util/report_scaling.py
index 5b4a4df7c84..02b3710c334 100644
--- a/pyomo/util/report_scaling.py
+++ b/pyomo/util/report_scaling.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -11,9 +11,9 @@
 
 import pyomo.environ as pyo
 import math
-from pyomo.core.base.block import _BlockData
+from pyomo.core.base.block import BlockData
 from pyomo.common.collections import ComponentSet
-from pyomo.core.base.var import _GeneralVarData
+from pyomo.core.base.var import Var
 from pyomo.contrib.fbbt.fbbt import compute_bounds_on_expr
 from pyomo.core.expr.calculus.diff_with_pyomo import reverse_sd
 import logging
@@ -42,7 +42,7 @@ def _print_var_set(var_set):
     return s
 
 
-def _check_var_bounds(m: _BlockData, too_large: float):
+def _check_var_bounds(m: BlockData, too_large: float):
     vars_without_bounds = ComponentSet()
     vars_with_large_bounds = ComponentSet()
     for v in m.component_data_objects(pyo.Var, descend_into=True):
@@ -73,7 +73,7 @@ def _check_coefficients(
 ):
     ders = reverse_sd(expr)
     for _v, _der in ders.items():
-        if isinstance(_v, _GeneralVarData):
+        if getattr(_v, 'ctype', None) is Var:
             if _v.is_fixed():
                 continue
             der_lb, der_ub = compute_bounds_on_expr(_der)
@@ -90,7 +90,7 @@ def _check_coefficients(
 
 
 def report_scaling(
-    m: _BlockData, too_large: float = 5e4, too_small: float = 1e-6
+    m: BlockData, too_large: float = 5e4, too_small: float = 1e-6
 ) -> bool:
     """
     This function logs potentially poorly scaled parts of the model.
@@ -107,7 +107,7 @@ def report_scaling(
 
     Parameters
     ----------
-    m: _BlockData
+    m: BlockData
         The pyomo model or block
     too_large: float
         Values above too_large will generate a log entry
diff --git a/pyomo/util/slices.py b/pyomo/util/slices.py
index 0449acb3f2f..d85aa3fa926 100644
--- a/pyomo/util/slices.py
+++ b/pyomo/util/slices.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -98,7 +98,7 @@ def slice_component_along_sets(comp, sets, context=None):
     sets: `pyomo.common.collections.ComponentSet`
         Contains the sets to replace with slices
     context: `pyomo.core.base.block.Block` or
-    `pyomo.core.base.block._BlockData`
+    `pyomo.core.base.block.BlockData`
         Block below which to search for sets
 
     Returns:
diff --git a/pyomo/util/subsystems.py b/pyomo/util/subsystems.py
index 673781def17..00c3b85ce47 100644
--- a/pyomo/util/subsystems.py
+++ b/pyomo/util/subsystems.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -14,21 +14,38 @@
 from pyomo.core.expr.visitor import identify_variables
 from pyomo.common.collections import ComponentSet, ComponentMap
 from pyomo.common.modeling import unique_component_name
-
+from pyomo.util.vars_from_expressions import get_vars_from_components
 from pyomo.core.base.constraint import Constraint
 from pyomo.core.base.expression import Expression
+from pyomo.core.base.objective import Objective
 from pyomo.core.base.external import ExternalFunction
 from pyomo.core.expr.visitor import StreamBasedExpressionVisitor
 from pyomo.core.expr.numeric_expr import ExternalFunctionExpression
-from pyomo.core.expr.numvalue import native_types
+from pyomo.core.expr.numvalue import native_types, NumericValue
 
 
 class _ExternalFunctionVisitor(StreamBasedExpressionVisitor):
+    def __init__(self, descend_into_named_expressions=True):
+        super().__init__()
+        self._descend_into_named_expressions = descend_into_named_expressions
+        self.named_expressions = []
+
     def initializeWalker(self, expr):
         self._functions = []
         self._seen = set()
         return True, None
 
+    def beforeChild(self, parent, child, index):
+        if child.__class__ in native_types:
+            return False, None
+        elif (
+            not self._descend_into_named_expressions
+            and child.is_named_expression_type()
+        ):
+            self.named_expressions.append(child)
+            return False, None
+        return True, None
+
     def exitNode(self, node, data):
         if type(node) is ExternalFunctionExpression:
             if id(node) not in self._seen:
@@ -38,17 +55,6 @@ def exitNode(self, node, data):
     def finalizeResult(self, result):
         return self._functions
 
-    def enterNode(self, node):
-        pass
-
-    def acceptChildResult(self, node, data, child_result, child_idx):
-        pass
-
-    def acceptChildResult(self, node, data, child_result, child_idx):
-        if child_result.__class__ in native_types:
-            return False, None
-        return child_result.is_expression_type(), None
-
 
 def identify_external_functions(expr):
     yield from _ExternalFunctionVisitor().walk_expression(expr)
@@ -56,8 +62,28 @@ def identify_external_functions(expr):
 
 def add_local_external_functions(block):
     ef_exprs = []
-    for comp in block.component_data_objects((Constraint, Expression), active=True):
-        ef_exprs.extend(identify_external_functions(comp.expr))
+    named_expressions = []
+    visitor = _ExternalFunctionVisitor(descend_into_named_expressions=False)
+    for comp in block.component_data_objects(
+        (Constraint, Expression, Objective), active=True
+    ):
+        ef_exprs.extend(visitor.walk_expression(comp.expr))
+    named_expr_set = ComponentSet(visitor.named_expressions)
+    # List of unique named expressions
+    named_expressions = list(named_expr_set)
+    while named_expressions:
+        expr = named_expressions.pop()
+        # Clear named expression cache so we don't re-check named expressions
+        # we've seen before.
+        visitor.named_expressions.clear()
+        ef_exprs.extend(visitor.walk_expression(expr))
+        # Only add to the stack named expressions that we have
+        # not encountered yet.
+        for local_expr in visitor.named_expressions:
+            if local_expr not in named_expr_set:
+                named_expressions.append(local_expr)
+                named_expr_set.add(local_expr)
+
     unique_functions = []
     fcn_set = set()
     for expr in ef_exprs:
@@ -106,11 +132,9 @@ def create_subsystem_block(constraints, variables=None, include_fixed=False):
     block.cons = Reference(constraints)
     var_set = ComponentSet(variables)
     input_vars = []
-    for con in constraints:
-        for var in identify_variables(con.expr, include_fixed=include_fixed):
-            if var not in var_set:
-                input_vars.append(var)
-                var_set.add(var)
+    for var in get_vars_from_components(block, Constraint, include_fixed=include_fixed):
+        if var not in var_set:
+            input_vars.append(var)
     block.input_vars = Reference(input_vars)
     add_local_external_functions(block)
     return block
@@ -148,7 +172,14 @@ class TemporarySubsystemManager(object):
 
     """
 
-    def __init__(self, to_fix=None, to_deactivate=None, to_reset=None, to_unfix=None):
+    def __init__(
+        self,
+        to_fix=None,
+        to_deactivate=None,
+        to_reset=None,
+        to_unfix=None,
+        remove_bounds_on_fix=False,
+    ):
         """
         Arguments
         ---------
@@ -168,6 +199,8 @@ def __init__(self, to_fix=None, to_deactivate=None, to_reset=None, to_unfix=None
             List of var data objects to be temporarily unfixed. These are
             restored to their original status on exit from this object's
             context manager.
+        remove_bounds_on_fix: Bool
+            Whether bounds should be removed temporarily for fixed variables
 
         """
         if to_fix is None:
@@ -194,6 +227,8 @@ def __init__(self, to_fix=None, to_deactivate=None, to_reset=None, to_unfix=None
         self._con_was_active = None
         self._comp_original_value = None
         self._var_was_unfixed = None
+        self._remove_bounds_on_fix = remove_bounds_on_fix
+        self._fixed_var_bounds = None
 
     def __enter__(self):
         to_fix = self._vars_to_fix
@@ -203,8 +238,13 @@ def __enter__(self):
         self._var_was_fixed = [(var, var.fixed) for var in to_fix + to_unfix]
         self._con_was_active = [(con, con.active) for con in to_deactivate]
         self._comp_original_value = [(comp, comp.value) for comp in to_set]
+        self._fixed_var_bounds = [(var.lb, var.ub) for var in to_fix]
 
         for var in self._vars_to_fix:
+            if self._remove_bounds_on_fix:
+                # TODO: Potentially override var.domain as well?
+                var.setlb(None)
+                var.setub(None)
             var.fix()
 
         for con in self._cons_to_deactivate:
@@ -223,6 +263,11 @@ def __exit__(self, ex_type, ex_val, ex_bt):
                 var.fix()
             else:
                 var.unfix()
+        if self._remove_bounds_on_fix:
+            for var, (lb, ub) in zip(self._vars_to_fix, self._fixed_var_bounds):
+                var.setlb(lb)
+                var.setub(ub)
+
         for con, was_active in self._con_was_active:
             if was_active:
                 con.activate()
diff --git a/pyomo/util/tests/__init__.py b/pyomo/util/tests/__init__.py
index e69de29bb2d..a4a626013c4 100644
--- a/pyomo/util/tests/__init__.py
+++ b/pyomo/util/tests/__init__.py
@@ -0,0 +1,10 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
diff --git a/pyomo/util/tests/test_blockutil.py b/pyomo/util/tests/test_blockutil.py
index 06b75bd6b68..dfe4f482fb2 100644
--- a/pyomo/util/tests/test_blockutil.py
+++ b/pyomo/util/tests/test_blockutil.py
@@ -2,7 +2,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/util/tests/test_calc_var_value.py b/pyomo/util/tests/test_calc_var_value.py
index 91f23dd5a5d..4bed4d5c843 100644
--- a/pyomo/util/tests/test_calc_var_value.py
+++ b/pyomo/util/tests/test_calc_var_value.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -101,6 +101,15 @@ def test_initialize_value(self):
         ):
             calculate_variable_from_constraint(m.x, m.lt)
 
+        m.indexed = Constraint([1, 2], rule=lambda m, i: m.x <= i)
+        with self.assertRaisesRegex(
+            ValueError,
+            r"calculate_variable_from_constraint\(\): constraint must be a scalar "
+            r"constraint or a single ConstraintData.  Received IndexedConstraint "
+            r'\("indexed"\)',
+        ):
+            calculate_variable_from_constraint(m.x, m.indexed)
+
     def test_linear(self):
         m = ConcreteModel()
         m.x = Var()
diff --git a/pyomo/util/tests/test_check_units.py b/pyomo/util/tests/test_check_units.py
index d2fb35c4f3b..9cde8d8dbae 100644
--- a/pyomo/util/tests/test_check_units.py
+++ b/pyomo/util/tests/test_check_units.py
@@ -2,7 +2,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/util/tests/test_components.py b/pyomo/util/tests/test_components.py
index 92eb7dd5ef1..1027815ca6b 100644
--- a/pyomo/util/tests/test_components.py
+++ b/pyomo/util/tests/test_components.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/util/tests/test_infeasible.py b/pyomo/util/tests/test_infeasible.py
index cefc129b41e..687a578e5c8 100644
--- a/pyomo/util/tests/test_infeasible.py
+++ b/pyomo/util/tests/test_infeasible.py
@@ -2,7 +2,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/util/tests/test_model_size.py b/pyomo/util/tests/test_model_size.py
index 417ff7526e8..2380d272a24 100644
--- a/pyomo/util/tests/test_model_size.py
+++ b/pyomo/util/tests/test_model_size.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/util/tests/test_report_scaling.py b/pyomo/util/tests/test_report_scaling.py
index b010065d697..2eaed2d0ade 100644
--- a/pyomo/util/tests/test_report_scaling.py
+++ b/pyomo/util/tests/test_report_scaling.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/util/tests/test_slices.py b/pyomo/util/tests/test_slices.py
index db66a74b468..992bdc0a332 100644
--- a/pyomo/util/tests/test_slices.py
+++ b/pyomo/util/tests/test_slices.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/util/tests/test_subsystems.py b/pyomo/util/tests/test_subsystems.py
index a081b51cee9..089888bd6a9 100644
--- a/pyomo/util/tests/test_subsystems.py
+++ b/pyomo/util/tests/test_subsystems.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -292,7 +292,7 @@ def test_generate_dont_fix_inputs_with_fixed_var(self):
         self.assertFalse(m.v3.fixed)
         self.assertTrue(m.v4.fixed)
 
-    def _make_model_with_external_functions(self):
+    def _make_model_with_external_functions(self, named_expressions=False):
         m = pyo.ConcreteModel()
         gsl = find_GSL()
         m.bessel = pyo.ExternalFunction(library=gsl, function="gsl_sf_bessel_J0")
@@ -300,9 +300,21 @@ def _make_model_with_external_functions(self):
         m.v1 = pyo.Var(initialize=1.0)
         m.v2 = pyo.Var(initialize=2.0)
         m.v3 = pyo.Var(initialize=3.0)
+        if named_expressions:
+            m.subexpr = pyo.Expression(pyo.PositiveIntegers)
+            m.subexpr[1] = 2 * m.fermi(m.v1)
+            m.subexpr[2] = m.bessel(m.v1) - m.bessel(m.v2)
+            m.subexpr[3] = m.subexpr[2] + m.v3**2
+            subexpr1 = m.subexpr[1]
+            subexpr2 = m.subexpr[2]
+            subexpr3 = m.subexpr[3]
+        else:
+            subexpr1 = 2 * m.fermi(m.v1)
+            subexpr2 = m.bessel(m.v1) - m.bessel(m.v2)
+            subexpr3 = subexpr2 + m.v3**2
         m.con1 = pyo.Constraint(expr=m.v1 == 0.5)
-        m.con2 = pyo.Constraint(expr=2 * m.fermi(m.v1) + m.v2**2 - m.v3 == 1.0)
-        m.con3 = pyo.Constraint(expr=m.bessel(m.v1) - m.bessel(m.v2) + m.v3**2 == 2.0)
+        m.con2 = pyo.Constraint(expr=subexpr1 + m.v2**2 - m.v3 == 1.0)
+        m.con3 = pyo.Constraint(expr=subexpr3 == 2.0)
         return m
 
     @unittest.skipUnless(find_GSL(), "Could not find the AMPL GSL library")
@@ -329,6 +341,15 @@ def test_identify_external_functions(self):
         pred_fcn_data = {(gsl, "gsl_sf_bessel_J0"), (gsl, "gsl_sf_fermi_dirac_m1")}
         self.assertEqual(fcn_data, pred_fcn_data)
 
+    @unittest.skipUnless(find_GSL(), "Could not find the AMPL GSL library")
+    def test_local_external_functions_with_named_expressions(self):
+        m = self._make_model_with_external_functions(named_expressions=True)
+        variables = list(m.component_data_objects(pyo.Var))
+        constraints = list(m.component_data_objects(pyo.Constraint, active=True))
+        b = create_subsystem_block(constraints, variables)
+        self.assertTrue(isinstance(b._gsl_sf_bessel_J0, pyo.ExternalFunction))
+        self.assertTrue(isinstance(b._gsl_sf_fermi_dirac_m1, pyo.ExternalFunction))
+
     def _solve_ef_model_with_ipopt(self):
         m = self._make_model_with_external_functions()
         ipopt = pyo.SolverFactory("ipopt")
@@ -362,6 +383,33 @@ def test_with_external_function(self):
         self.assertAlmostEqual(m.v2.value, m_full.v2.value)
         self.assertAlmostEqual(m.v3.value, m_full.v3.value)
 
+    @unittest.skipUnless(find_GSL(), "Could not find the AMPL GSL library")
+    @unittest.skipUnless(
+        pyo.SolverFactory("ipopt").available(), "ipopt is not available"
+    )
+    def test_with_external_function_in_named_expression(self):
+        m = self._make_model_with_external_functions(named_expressions=True)
+        subsystem = ([m.con2, m.con3], [m.v2, m.v3])
+
+        m.v1.set_value(0.5)
+        block = create_subsystem_block(*subsystem)
+        ipopt = pyo.SolverFactory("ipopt")
+        with TemporarySubsystemManager(to_fix=list(block.input_vars.values())):
+            ipopt.solve(block)
+
+        # Correct values obtained by solving with Ipopt directly
+        # in another script.
+        self.assertEqual(m.v1.value, 0.5)
+        self.assertFalse(m.v1.fixed)
+        self.assertAlmostEqual(m.v2.value, 1.04816, delta=1e-5)
+        self.assertAlmostEqual(m.v3.value, 1.34356, delta=1e-5)
+
+        # Result obtained by solving the full system
+        m_full = self._solve_ef_model_with_ipopt()
+        self.assertAlmostEqual(m.v1.value, m_full.v1.value)
+        self.assertAlmostEqual(m.v2.value, m_full.v2.value)
+        self.assertAlmostEqual(m.v3.value, m_full.v3.value)
+
     @unittest.skipUnless(find_GSL(), "Could not find the AMPL GSL library")
     def test_external_function_with_potential_name_collision(self):
         m = self._make_model_with_external_functions()
diff --git a/pyomo/util/vars_from_expressions.py b/pyomo/util/vars_from_expressions.py
index 8866ba980bd..878a1a13b58 100644
--- a/pyomo/util/vars_from_expressions.py
+++ b/pyomo/util/vars_from_expressions.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -43,6 +43,7 @@ def get_vars_from_components(
         descent_order: Traversal strategy for finding the objects of type ctype
     """
     seen = set()
+    named_expression_cache = {}
     for constraint in block.component_data_objects(
         ctype,
         active=active,
@@ -51,7 +52,9 @@ def get_vars_from_components(
         descent_order=descent_order,
     ):
         for var in EXPR.identify_variables(
-            constraint.expr, include_fixed=include_fixed
+            constraint.expr,
+            include_fixed=include_fixed,
+            named_expression_cache=named_expression_cache,
         ):
             if id(var) not in seen:
                 seen.add(id(var))
diff --git a/pyomo/version/__init__.py b/pyomo/version/__init__.py
index 08bcde304a6..acc92ff6b37 100644
--- a/pyomo/version/__init__.py
+++ b/pyomo/version/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/version/info.py b/pyomo/version/info.py
index cedb30c2dd4..825483a70a0 100644
--- a/pyomo/version/info.py
+++ b/pyomo/version/info.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -26,7 +26,7 @@
 # main and needs a hard reference to "suitably new" development.
 major = 6
 minor = 7
-micro = 1
+micro = 4
 releaselevel = 'invalid'
 # releaselevel = 'final'
 serial = 0
diff --git a/pyomo/version/tests/__init__.py b/pyomo/version/tests/__init__.py
index 9fb4f531a5b..f013ccd3fa3 100644
--- a/pyomo/version/tests/__init__.py
+++ b/pyomo/version/tests/__init__.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/version/tests/check.py b/pyomo/version/tests/check.py
index ab3b45ffc6c..0fca9badb2f 100644
--- a/pyomo/version/tests/check.py
+++ b/pyomo/version/tests/check.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/pyomo/version/tests/test_version.py b/pyomo/version/tests/test_version.py
index 253ee53137c..3b39bd71cb1 100644
--- a/pyomo/version/tests/test_version.py
+++ b/pyomo/version/tests/test_version.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/scripts/admin/contributors.py b/scripts/admin/contributors.py
index fe5d483f16d..ffc02059d6f 100644
--- a/scripts/admin/contributors.py
+++ b/scripts/admin/contributors.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/scripts/get_pyomo.py b/scripts/get_pyomo.py
index a97c0ba3a00..d90773f2315 100644
--- a/scripts/get_pyomo.py
+++ b/scripts/get_pyomo.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/scripts/get_pyomo_extras.py b/scripts/get_pyomo_extras.py
index d2aa097154a..6688f3c6dc4 100644
--- a/scripts/get_pyomo_extras.py
+++ b/scripts/get_pyomo_extras.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/scripts/performance/compare.py b/scripts/performance/compare.py
index 5edef9bfadd..e62440fd6d9 100755
--- a/scripts/performance/compare.py
+++ b/scripts/performance/compare.py
@@ -2,7 +2,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/scripts/performance/compare_components.py b/scripts/performance/compare_components.py
index f390fad8454..764b50217ef 100644
--- a/scripts/performance/compare_components.py
+++ b/scripts/performance/compare_components.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 #
 # This script compares build time and memory usage for
 # various modeling objects. The output is organized into
diff --git a/scripts/performance/expr_perf.py b/scripts/performance/expr_perf.py
index 6566431b9f3..9abdd560887 100644
--- a/scripts/performance/expr_perf.py
+++ b/scripts/performance/expr_perf.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 #
 # This script runs performance tests on expressions
 #
diff --git a/scripts/performance/main.py b/scripts/performance/main.py
index 10349c0eb73..07dc38a11a7 100755
--- a/scripts/performance/main.py
+++ b/scripts/performance/main.py
@@ -2,7 +2,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
diff --git a/scripts/performance/simple.py b/scripts/performance/simple.py
index 2990f13f413..c5fb836b64b 100644
--- a/scripts/performance/simple.py
+++ b/scripts/performance/simple.py
@@ -1,3 +1,14 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
 from pyomo.environ import *
 import pyomo.core.expr.current as EXPR
 import timeit
diff --git a/setup.cfg b/setup.cfg
index b606138f38c..f670cef8f68 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -22,3 +22,4 @@ markers =
     lp: marks lp tests
     gams: marks gams tests
     bar: marks bar tests
+    builders: tests that should be run when testing custom (extension) builders
\ No newline at end of file
diff --git a/setup.py b/setup.py
index e2d702db010..6d28e4d184b 100644
--- a/setup.py
+++ b/setup.py
@@ -1,7 +1,7 @@
 #  ___________________________________________________________________________
 #
 #  Pyomo: Python Optimization Modeling Objects
-#  Copyright (c) 2008-2022
+#  Copyright (c) 2008-2024
 #  National Technology and Engineering Solutions of Sandia, LLC
 #  Under the terms of Contract DE-NA0003525 with National Technology and
 #  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
@@ -253,6 +253,9 @@ def __ne__(self, other):
             'sphinx_rtd_theme>0.5',
             'sphinxcontrib-jsmath',
             'sphinxcontrib-napoleon',
+            'sphinx-toolbox>=2.16.0',
+            'sphinx-jinja2-compat>=0.1.1',
+            'enum_tools',
             'numpy',  # Needed by autodoc for pynumero
             'scipy',  # Needed by autodoc for pynumero
         ],
@@ -261,7 +264,9 @@ def __ne__(self, other):
             'ipython',  # contrib.viewer
             # Note: matplotlib 3.6.1 has bug #24127, which breaks
             # seaborn's histplot (triggering parmest failures)
-            'matplotlib!=3.6.1',
+            # Note: minimum version from community_detection use of
+            # matplotlib.pyplot.get_cmap()
+            'matplotlib>=3.6.0,!=3.6.1',
             # network, incidence_analysis, community_detection
             # Note: networkx 3.2 is Python>-3.9, but there is a broken
             # 3.2 package on conda-forge that will get implicitly
@@ -303,6 +308,7 @@ def __ne__(self, other):
         "pyomo.contrib.mcpp": ["*.cpp"],
         "pyomo.contrib.pynumero": ['src/*', 'src/tests/*'],
         "pyomo.contrib.viewer": ["*.ui"],
+        "pyomo.contrib.simplification.ginac": ["src/*.cpp", "src/*.hpp"],
     },
     ext_modules=ext_modules,
     entry_points="""