public static int GetIndex(PDLComparisonOperator op)
        {
            switch (op)
            {
            case PDLComparisonOperator.Eq: return(0);

            case PDLComparisonOperator.Ge: return(1);

            case PDLComparisonOperator.Geq: return(2);

            case PDLComparisonOperator.Le: return(3);

            case PDLComparisonOperator.Leq: return(4);

            default: throw new PDLException("undefined operator");
            }
        }
 public static bool IsSymmetric(PDLComparisonOperator op)
 {
     return op == PDLComparisonOperator.Eq;
 }
 public static int GetIndex(PDLComparisonOperator op)
 {
     switch (op)
     {
         case PDLComparisonOperator.Eq: return 0;
         case PDLComparisonOperator.Ge: return 1;
         case PDLComparisonOperator.Geq: return 2;
         case PDLComparisonOperator.Le: return 3;
         case PDLComparisonOperator.Leq: return 4;
         default: throw new PDLException("undefined operator");
     }
 }
 public static bool IsSymmetric(PDLComparisonOperator op)
 {
     return(op == PDLComparisonOperator.Eq);
 }