anchor.diff:      | _    -> Seq.concat [Seq.singleton list.Head
                             messageSeq list.Tail]
   
  -let rec private produceMessage (indent: int) (expectedWordWritten: bool) (message : ErrorMessage) : bool * string =
  +let rec private produceMessage (expectedWordWritten: bool) (message : ErrorMessage) : bool * string =
       let expected = if not expectedWordWritten
                      then "Expected "
                      else "      or "
  
positive.code: let private getMessage (message : string) (error : ParserError) (userState : ParserState) : string =
      if enabled then
          let position = error.Position
          sprintf "At line %d, column %d: %s" position.Line position.Column <| produceErrorMessageList 0 error.Messages
      else message
  
  let getException message (error : ParserError) userState =
  
negative.code:     let result = 
          match message with
          | NestedError(position, userState, errors)          ->
              false, sprintf "Nested errors: %s"   <| produceErrorMessageList errors
          | CompoundError(label, position, userState, errors) ->
              false, sprintf "Compound errors: %s" <| produceErrorMessageList errors
          | Expected           label -> true, expected + String.Format(CompilerMessages.LexemExpected, label)
          | ExpectedString     str
          | ExpectedStringCI   str   -> true, expected + String.Format(CompilerMessages.StringExpected, str)
  