internal class Term
{
  internal string functor = null;
  internal ArrayList body = null;
  internal double number = Double.NaN;
  internal bool isInteger = false;

  internal Term (double n)
    {
      number = n;
    }

  internal Term (int n)
    {
      number = n;
      isInteger = true;
    }

  internal Term (string functor)
    {
      this.functor = functor;
    }

  internal Term (string functor, ArrayList body)
    {
      this.functor = functor;
      this.body = body;
    }

  internal bool IsNumber
    {
      get { return !Double.IsNaN(number); }
    }

  internal bool HasBody
    {
      get { return (body != null && body.Count != 0); }
    }

  public override string ToString ()
    {
      if (IsNumber)
        return (isInteger ? ((int)number).ToString()
                          : number.ToString());

      if (!HasBody)
        return functor;
      
      StringBuilder s = new StringBuilder(functor);

      s.Append("(");
      for (int i=0; i<body.Count; i++)
        {
          s.Append(body[i]);
          if (i<body.Count-1)
	    s.Append(",");
        }
      s.Append(")");

      return s.ToString();
    }
}