anchor.diff:  begin
     TempSucc := false;
     if Assigned(FOnCalcUserFunction) then
  -    FOnCalcUserFunction(Self, funct, ParametersList, Result, TempSucc);
  +    FOnCalcUserFunction(Self, funct, ParametersList, Result, TempSucc)
  +  else
  +    Result := 0;
   
     if not TempSucc then
       RaiseError(sFunctionError, funct);
  
positive.code: 
  uses
    Classes, variants, sysutils,
    mArrays, mNullables;
  
  const
    sInvalidString = 1;
  
negative.code:     // Lexical Analyzer Function http://www.gnu.org/software/bison/manual/html_node/Lexical.html
      procedure yylex (var lexState: TLexState; var lexResult : TLexResult);
      // double
      procedure StartCalculate(out resValue: double; var lexState: TLexState; var lexResult : TLexResult);
      procedure Calc6(var resValue: double; var lexState: TLexState; var lexResult : TLexResult);
      procedure Calc5(var resValue: double; var lexState: TLexState; var lexResult : TLexResult);
      procedure Calc4(var resValue: double; var lexState: TLexState; var lexResult : TLexResult);
  