Update README.md

README.md

@@ -6,9 +6,9 @@
 Provides a basic implementation of weight-balanced binary trees.
 
 The WBTrees library contains classes as follows:
-- A list by a weight-balanced binary tree, with all `O(log n)` operations
+- A list by a weight-balanced binary tree, with all `O(log n)` basic operations
   - `WBList<T>`
-- Weight-balanced binary search trees, which can be accessed by index in `O(log n)` time
+- A set and a map by weight-balanced binary search trees, which can be accessed by index in `O(log n)` time
   - `WBSet<T>`
   - `WBMultiSet<T>`
   - `WBMap<TKey, TValue>`
@@ -23,10 +23,10 @@ You are welcome to port this to other languages.
 ## Features
 
 ### A List by a Weight-Balanced Binary Tree
-Provides the `WBList<T>` class as a list with all `O(log n)` operations.  
-You can also use a `WBList<T>` as a double-ended queue (deque).
+Provides the `WBList<T>` class as a list with all `O(log n)` basic operations.  
+You can also use a `WBList<T>` as a (high-grade) double-ended queue (deque).
 
-The following table compares time complexities of [`List<T>`](https://docs.microsoft.com/dotnet/api/system.collections.generic.list-1) and `WBList<T>`:
+The following table compares time complexities of [`System.Collections.Generic.List<T>`](https://docs.microsoft.com/dotnet/api/system.collections.generic.list-1) and `WBList<T>`:
 | Operation | `List<T>` | `WBList<T>` |
 |:--|:-:|:-:|
 | Get by Index | `O(1)` | `O(log n)` |
@@ -37,11 +37,11 @@ The following table compares time complexities of [`List<T>`](https://docs.micro
 | Add | `O(1)` | `O(log n)` |
 | Get All | `O(n)` | `O(n)` |
 
-### Weight-Balanced Binary Search Trees
+### A Set and a Map by Weight-Balanced Binary Search Trees
 Provides the `WBSet<T>`, `WBMultiSet<T>`, `WBMap<TKey, TValue>` and `WBMultiMap<TKey, TValue>` classes, which can be accessed by index in `O(log n)` time. All these classes are derived from the `WBTreeBase<T>` class.  
-You can also use a `WBMultiSet<T>` or a `WBMultiMap<TKey, TValue>` as a priority queue with stable sorting.
+You can also use a `WBMultiSet<T>` or a `WBMultiMap<TKey, TValue>` as a priority queue with stable sorting or a double-ended priority queue.
 
-The following table compares time complexities of [`SortedSet<T>`](https://docs.microsoft.com/dotnet/api/system.collections.generic.sortedset-1) and `WBSet<T>`:
+The following table compares time complexities of [`System.Collections.Generic.SortedSet<T>`](https://docs.microsoft.com/dotnet/api/system.collections.generic.sortedset-1) and `WBSet<T>`:
 | Operation | `SortedSet<T>` | `WBSet<T>` |
 |:--|:-:|:-:|
 | Get by Item | `O(log n)` | `O(log n)` |
@@ -53,8 +53,8 @@ The following table compares time complexities of [`SortedSet<T>`](https://docs.
 | Get All | `O(n)` | `O(n)` |
 
 ## Algorithm
-Both `WBList<T>` and `WBTreeBase<T>` are weight-balanced binary trees.
-The `Node<T>` class contains the `Count` property that contributes to both self-balancing and direct access by index (order).
+Both `WBList<T>` and `WBTreeBase<T>` are weight-balanced binary trees (not necessarily searchable by items).
+The `Node<T>` class contains the `Count` property that contributes to both self-balancing and fast access by index (order).
 
 ## Target Frameworks
 - .NET 5
@@ -65,7 +65,7 @@ The `Node<T>` class contains the `Count` property that contributes to both self-
 The WBTrees library is published to [NuGet Gallery](https://www.nuget.org/packages/WBTrees/).
 Install the NuGet package via Visual Studio, etc.
 
-You can also [download a single source file here](downloads), for competitive programming, etc.
+You can also [download a single source file here](downloads) for competitive programming, etc.
 
 ## Usage
 See [Usage on Wiki](https://github.com/sakapon/WBTrees/wiki/Usage) for coding.