anchor.diff:  
       let tool = parameters.ToolDirectory @@ "light.exe"
       let args = 
  -            sprintf "\"%s\" -spdb -dcl:high -out \"%s\" -ext WiXNetFxExtension -ext WixUIExtension.dll -ext WixUtilExtension.dll" 
  +            sprintf "\"%s\" -spdb -dcl:high -out \"%s\" %s" 
                   (wixObj |> FullName)
                   (outputFile |> FullName)
  +                (separated " " parameters.AdditionalLightArgs)
   
       tracefn "%s %s" parameters.ToolDirectory args
       if not (execProcess3 (fun info ->  
  
positive.code: 
      let tool = parameters.ToolDirectory @@ "candle.exe"
      let args = 
          sprintf "-out \"%s\" \"%s\" -ext WiXNetFxExtension" 
              wixObj
              (wixScript |> FullName)
  
      tracefn "%s %s" parameters.ToolDirectory args
      if not (execProcess3 (fun info ->  
  
negative.code: 
  type WiXParams = 
      { ToolDirectory: string;
        TimeOut: TimeSpan;
        AdditionalCandleArgs: string list;
        AdditionalLightArgs: string list;
         }
  
  /// WiX default params  
  let WiXDefaults : WiXParams = 
      { ToolDirectory = currentDirectory @@ "tools" @@ "Wix";
        TimeOut = TimeSpan.FromMinutes 5.0;
        AdditionalCandleArgs = [ "-ext WiXNetFxExtension" ];
        AdditionalLightArgs = [ "-ext WiXNetFxExtension"; "-ext WixUIExtension.dll"; "-ext WixUtilExtension.dll" ] }
     
  let Candle (parameters:WiXParams) wixScript = 
      traceStartTask "Candle" wixScript  
  