public Type checkType(TypeMap tm)
	{
		Type t = new Type();
		t.typeid = Type.TypeEnum.t_error;
		Type tmp = e.checkType(tm);
		if(tmp.OK())
		{
			if(tmp.typeid == Type.TypeEnum.t_list)
			{
				t = tmp;
			}
			else
			{
				if(Type.isDebug)
				{
					System.out.println("TypeError! tail: "+tmp.typeid);
					System.out.println(this);
				}
			}
		}
		return t;
	}