anchor.diff:        finally
           Console.SetOut(prev)
       with e ->
  -      match e.InnerException with
  -      | null -> errStream.WriteLine (sprintf "Error evaluating expression (%s):\n%s" e.Message text)
  -      | WrappedError(err, _) -> errStream.WriteLine (sprintf "Error evaluating expression (%s):\n%s" err.Message text)
  -      | _ -> errStream.WriteLine (sprintf "Error evaluating expression (%s):\n%s" e.Message text)
  +      evalFailed.Trigger({ File=file; AsExpression=asExpression; Text=text; Exception=e })
         { Output = None; Result = None; ItValue = None }
   
  -    member x.Errors = errStream.ToString()+    /// This event is fired whenever an evaluation of an expression fails
  +    member x.EvaluationFailed = evalFailed.Publish
positive.code:     ItValue : (obj * Type) option
      Result : (obj * Type) option }
  
  /// A wrapper for F# interactive serivice that is used to evaluate inline snippets
  type FsiEvaluator(?options:string[]) =
    // Initialize F# Interactive evaluation session
  
negative.code:   let fsiConfig = FsiEvaluationSession.GetDefaultConfiguration(new InteractiveSettings())
    let argv = Array.append [|"C:\\test.exe"; "--quiet"; "--noninteractive"|] (defaultArg options [||])
    let fsiSession = FsiEvaluationSession(fsiConfig, argv, inStream, outStream, errStream)
    let evalFailed = new Event<_>()
  
    /// Registered transformations for pretty printing values
    /// (the default formats value as a string and emits single CodeBlock)
  