public Type type_check(Table<Type> t_env,Table<Dec> v_env,boolean in_loop,ErrorList e){
		if(list==null){
			the_type = Type.THE_VOID;
			return the_type;
		}
		else{
			Type tmp=null;
			for(Expr ee:list.list)
				tmp = ee.type_check(t_env, v_env, in_loop, e);
			if(tmp==null){
				the_type = Type.THE_VOID;
				return the_type;
			}
			else{
				the_type = tmp;
				return the_type;
			}
		}
	}