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 ## Contents
 
-* [Introduction](##Introduction)
-* [Why Writing Nasal Interpreter](##Why-Writing-Nasal-Interpreter)
-* [Compile](##How-to-Compile)
-* [Usage](##How-to-Use)
-* [Parser](##Parser)
-  * [v1.0](###Version-1.0-parser-(last-update-2019/10/14))
-* [Abstract Syntax Tree](##Abstract-Syntax-Tree)
-  * [v1.2](###Version-1.2-ast-(last-update-2019/10/31))
-  * [v2.0](###Version-2.0-ast-(last-update-2020/8/31))
-  * [v3.0](###Version-3.0-ast-(last-update-2020/10/23))
-  * [v5.0](###Version-5.0-ast-(last-update-2021/3/7))
-* [Bytecode VM](##Bytecode-Virtual-Machine)
-  * [v4.0](###Version-4.0-vm-(last-update-2020/12/17))
-  * [v5.0](###Version-5.0-vm-(last-update-2021/3/7))
-  * [v6.0](###Version-6.0-vm-(last-update-2021/6/1))
-  * [v6.5](###Version-6.5-vm-(last-update-2021/6/24))
-  * [v7.0](###Version-7.0-vm-(last-update-2021/10/8))
-  * [v8.0](###Version-8.0-vm-(latest))
-* [Benchmark](##Benchmark)
-  * [v6.5 (i5-8250U windows 10)](###Version-6.5-(i5-8250U-windows10-2021/6/19))
-  * [v6.5 (i5-8250U ubuntu-WSL)](###Version-7.0-(i5-8250U-ubuntu-WSL-on-windows10-2021/6/29))
-* [Tutorial](##Simple-Tutorial)
-  * [basic value type](###__Basic-Value-Type__)
-  * [operators](###__Operators__)
-  * [definition](###__Definition__)
-  * [multi-assignment](###__Multi-Assignment__)
-  * [conditional expression](###__Conditional-Expression__)
-  * [loop](###__Loop__)
-  * [subvec](###__Subvec__)
-  * [special function call](###__Special-Function-Call__)
-  * [lambda](###__Lambda__)
-  * [closure](###__Closure__)
-  * [trait](###__Trait__)
-  * [native functions](###__Native-Functions__)
-  * [modules](###__Modules(This-is-for-library-developers)__)
-* [Difference](##Difference-Between-Andy's-Nasal-Interpreter-and-This-Interpreter)
-* [Trace Back Info](##Trace-Back-Info)
-* [Debugger](##Debugger)
+* [Introduction](#Introduction)
+* [Why Writing Nasal Interpreter](#Why-Writing-Nasal-Interpreter)
+* [Compile](#How-to-Compile)
+* [Usage](#How-to-Use)
+* [Parser](#Parser)
+  * [v1.0](#Version-1.0-parser-(last-update-2019/10/14))
+* [Abstract Syntax Tree](#Abstract-Syntax-Tree)
+  * [v1.2](#Version-1.2-ast-(last-update-2019/10/31))
+  * [v2.0](#Version-2.0-ast-(last-update-2020/8/31))
+  * [v3.0](#Version-3.0-ast-(last-update-2020/10/23))
+  * [v5.0](#Version-5.0-ast-(last-update-2021/3/7))
+* [Bytecode VM](#Bytecode-Virtual-Machine)
+  * [v4.0](#Version-4.0-vm-(last-update-2020/12/17))
+  * [v5.0](#Version-5.0-vm-(last-update-2021/3/7))
+  * [v6.0](#Version-6.0-vm-(last-update-2021/6/1))
+  * [v6.5](#Version-6.5-vm-(last-update-2021/6/24))
+  * [v7.0](#Version-7.0-vm-(last-update-2021/10/8))
+  * [v8.0](#Version-8.0-vm-(latest))
+* [Benchmark](#Benchmark)
+  * [v6.5 (i5-8250U windows 10)](#Version-6.5-(i5-8250U-windows10-2021/6/19))
+  * [v6.5 (i5-8250U ubuntu-WSL)](#Version-7.0-(i5-8250U-ubuntu-WSL-on-windows10-2021/6/29))
+* [Tutorial](#Simple-Tutorial)
+  * [basic value type](#__Basic-Value-Type__)
+  * [operators](#__Operators__)
+  * [definition](#__Definition__)
+  * [multi-assignment](#__Multi-Assignment__)
+  * [conditional expression](#__Conditional-Expression__)
+  * [loop](#__Loop__)
+  * [subvec](#__Subvec__)
+  * [special function call](#__Special-Function-Call__)
+  * [lambda](#__Lambda__)
+  * [closure](#__Closure__)
+  * [trait](#__Trait__)
+  * [native functions](#__Native-Functions__)
+  * [modules](#__Modules(This-is-for-library-developers)__)
+* [Difference](#Difference-Between-Andy's-Nasal-Interpreter-and-This-Interpreter)
+* [Trace Back Info](#Trace-Back-Info)
+* [Debugger](#Debugger)
 
 ## Introduction