/// <summary>コピーコンストラクタ。</summary>
		/// <param name="previous"></param>
		public FunctionData(FunctionData previous) : base( previous )
			{
			Expression = previous.Expression;
			}
 /// <summary>コピーコンストラクタ。</summary>
 /// <param name="previous"></param>
 public FunctionData(FunctionData previous) : base(previous)
 {
     Expression = previous.Expression;
 }