diff --git a/src/language/bytecode.ts b/src/language/bytecode.ts
index 980a123..3d1be9e 100644
--- a/src/language/bytecode.ts
+++ b/src/language/bytecode.ts
@@ -120,11 +120,15 @@ export function outputProgram(prog: IndexedProgram) {
       });
     }
   });
+
   const indexRules = prog.indexInsertionRules.map((value) => {
     const varToIndex = new Map<string, number>();
-    for (const [index, varName] of value.introduced.entries()) {
+    for (const [index, varName] of value.shared.entries()) {
       varToIndex.set(varName, index);
     }
+    for (const [index, varName] of value.introduced.entries()) {
+      varToIndex.set(varName, index + value.shared.length);
+    }
 
     return new Rule({
       is: {
@@ -139,6 +143,7 @@ export function outputProgram(prog: IndexedProgram) {
       },
     });
   });
+
   const conclusionRules = prog.conclusionRules.map((value) => {
     const varToIndex = new Map<string, number>();
     for (const [index, varName] of value.inVars.entries()) {