子界的问题

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    btn1: TButton;
    procedure btn1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}
type
  MySet = set of 0..254 ;
procedure TForm1.btn1Click(Sender: TObject);
var
  myS : MySet;
begin
        if 2 in myS then
                ShowMessage('ok')
        else
                ShowMessage('error');
end;

end.

-----------------------------
为什么显示的error,2不在0..254范围内吗？ delphi 子界类型
[解决办法]
myS是空的，没赋值啊
[解决办法]

procedure TForm1.btn1Click(Sender: TObject);
var
  myS : MySet;
begin
  myS := [0, 1, 2, 3];
        if 2 in myS then
                ShowMessage('ok')
        else
                ShowMessage('error');
end;