diff --git a/version2.0/abstract_syntax_tree.h b/version2.0/abstract_syntax_tree.h
deleted file mode 100644
index 9e7b634..0000000
--- a/version2.0/abstract_syntax_tree.h
+++ /dev/null
@@ -1,251 +0,0 @@
-#ifndef __ABSTRACT_SYNTAX_TREE_H__
-#define __ABSTRACT_SYNTAX_TREE_H__
-
-class abstract_syntax_tree
-{
-	private:
-		// basic elements
-		int line;
-		int symbol_number;
-		bool symbol_is_global;
-		int node_type;
-		std::list<abstract_syntax_tree> children;
-
-		// is this node is a number|string|identifier node
-		// then the three elements below is of great use
-		double var_number;
-		std::string var_string;
-		std::string var_name;
-		// var_name is set for __id
-	public:
-		// basic
-		abstract_syntax_tree();
-		abstract_syntax_tree(const abstract_syntax_tree&);
-		~abstract_syntax_tree();
-		abstract_syntax_tree& operator=(const abstract_syntax_tree&);
-		
-		// main functions
-		// print
-		void print_tree();
-		void print_tree_block(const int);
-
-		// set
-		void set_clear();
-		void set_node_type(const int);
-		void set_node_line(const int);
-		void set_symbol_number(const int);
-		void set_var_string(std::string);
-		void set_var_number(std::string);
-		void set_var_name(std::string);
-		void set_var_scope(bool);// true means it exists in global scope
-		void add_children(abstract_syntax_tree);
-
-		// get
-		int get_node_type();
-		int get_node_line();
-		int get_symbol_number();
-		double get_var_number();
-		std::string get_var_string();
-		std::string get_var_name();
-		bool get_var_scope();
-		std::list<abstract_syntax_tree>& get_children();
-};
-
-abstract_syntax_tree::abstract_syntax_tree()
-{
-	node_type=__null_type;
-	line=0;
-	symbol_number=-1;
-	symbol_is_global=false;
-	var_number=0;
-	var_string="";
-	var_name="";
-	children.clear();
-	return;
-}
-
-abstract_syntax_tree::abstract_syntax_tree(const abstract_syntax_tree& tmp)
-{
-	node_type=tmp.node_type;
-	line=tmp.line;
-	symbol_number=tmp.symbol_number;
-	symbol_is_global=tmp.symbol_is_global;
-	var_number=tmp.var_number;
-	var_string=tmp.var_string;
-	var_name=tmp.var_name;
-	children=tmp.children;
-	return;
-}
-
-abstract_syntax_tree::~abstract_syntax_tree()
-{
-	node_type=__null_type;
-	line=0;
-	symbol_number=-1;
-	symbol_is_global=false;
-	var_number=0;
-	var_string.clear();
-	var_name.clear();
-	children.clear();
-	return;
-}
-
-abstract_syntax_tree& abstract_syntax_tree::operator=(const abstract_syntax_tree& tmp)
-{
-	node_type=tmp.node_type;
-	line=tmp.line;
-	symbol_number=tmp.symbol_number;
-	symbol_is_global=tmp.symbol_is_global;
-	var_number=tmp.var_number;
-	var_string=tmp.var_string;
-	var_name=tmp.var_name;
-	children.clear();
-	children=tmp.children;
-	return *this;
-}
-
-void abstract_syntax_tree::print_tree()
-{
-	std::cout<<">> [Abstract-syntax-tree] get tree root: "<<(this)<<""<<std::endl;
-	print_tree_block(1);
-	return;
-}
-
-void abstract_syntax_tree::print_tree_block(const int n)
-{
-	std::string __str="";
-	for(int i=0;i<n;++i)
-		__str+="| ";
-	std::cout<<__str;
-	print_parse_token(node_type);
-	switch(node_type)
-	{
-		case __number: std::cout<<": "<<var_number;break;
-		case __string: std::cout<<": "<<var_string;break;
-		case __id:
-		case __dynamic_id:
-		case __call_hash:
-			std::cout<<": "<<var_name<<" (sym_num:"<<symbol_number<<"["<<(symbol_is_global? "global":"local")<<"])";
-			break;
-		case __call_vector:
-		case __call_function:break;
-		default:break;
-	}
-	std::cout<<std::endl;
-	if(!children.empty())
-	{
-		for(std::list<abstract_syntax_tree>::iterator i=children.begin();i!=children.end();++i)
-			i->print_tree_block(n+1);
-	}
-	return;
-}
-
-void abstract_syntax_tree::set_clear()
-{
-	node_type=__null_type;
-	line=0;
-	symbol_number=-1;
-	var_number=0;
-	var_string="";
-	var_name="";
-	children.clear();
-	return;
-}
-
-void abstract_syntax_tree::set_node_type(const int __node_type)
-{
-	node_type=__node_type;
-	return;
-}
-
-void abstract_syntax_tree::set_node_line(const int __line)
-{
-	if(__line>=0)
-		line=__line;
-	else
-	{
-		std::cout<<">> [Abstract-syntax-tree-warning] incorrect line under 0: "<<__line<<"."<<std::endl;
-		line=0;
-	}
-	return;
-}
-
-void abstract_syntax_tree::set_symbol_number(const int __sym_num)
-{
-	symbol_number=__sym_num;
-	return;
-}
-
-void abstract_syntax_tree::set_var_string(std::string __str)
-{
-	var_string=__str;
-	return;
-}
-
-void abstract_syntax_tree::set_var_number(std::string __str)
-{
-	var_number=trans_string_to_number(__str);
-	return;
-}
-
-void abstract_syntax_tree::set_var_name(std::string __str)
-{
-	var_name=__str;
-	return;
-}
-
-void abstract_syntax_tree::set_var_scope(bool is_global)
-{
-	symbol_is_global=is_global;
-	return;
-}
-
-void abstract_syntax_tree::add_children(abstract_syntax_tree p)
-{
-	// use abstract_syntax_tree instead of abstract_syntax_tree&
-	// because when this function get a 'p' from returned value of
-	// another function,this may result in s SIGSEGV.
-	children.push_back(p);
-	return;
-}
-
-int abstract_syntax_tree::get_node_type()
-{
-	return node_type;
-}
-
-int abstract_syntax_tree::get_node_line()
-{
-	return line;
-}
-
-int abstract_syntax_tree::get_symbol_number()
-{
-	return symbol_number;
-}
-
-double abstract_syntax_tree::get_var_number()
-{
-	return var_number;
-}
-
-std::string abstract_syntax_tree::get_var_string()
-{
-	return var_string;
-}
-
-std::string abstract_syntax_tree::get_var_name()
-{
-	return var_name;
-}
-
-bool abstract_syntax_tree::get_var_scope()
-{
-	return symbol_is_global;
-}
-
-std::list<abstract_syntax_tree>& abstract_syntax_tree::get_children()
-{
-	return children;
-}
-#endif