public override WS1SFormula ToWS1S(CharSetSolver solver)
 {
     if (WS1S == null)
     {
         WS1S = new WS1SLessOrEqual(var1, var2);
     }
     return(WS1S);
 }
 public override WS1SFormula ToWS1S(CharSetSolver solver)
 {
     if (WS1S == null)
         WS1S = new WS1SLessOrEqual(var1,var2);
     return WS1S;
 }