using uCalcSoftware;

var uc = new uCalc();

static void ValidateValue(uCalc.Callback cb) {
   var val = cb.Arg(1);
   if (val > 100) {
      // The error message includes the problematic value, making it dynamic.
      cb.Error.Raise("Value exceeds maximum of 100. Got: " + val.ToString());
   } else {
      cb.Return(val);
   }
}

uc.DefineFunction("CheckValue(val)", ValidateValue);
Console.WriteLine(uc.EvalStr("CheckValue(50)"));
Console.WriteLine(uc.EvalStr("CheckValue(123)"));