anchor.diff:  ///     </para>
   /// </summary>
   let parseSymbolic =
  -    pipe2ws
  +    (pipe2ws
           (pstring "%" >>. inBraces parseSymbolicSentence)
           (parseParamList parseExpression)
  -        (fun s es -> { Sentence = s; Args = es })
  +        (fun s es -> { Sentence = s; Args = es })) <?> "symbolic"
   
   /// Parser for primary expressions.
   let parsePrimaryExpression =
  
positive.code: let pipe3ws x y z f = pipe3 (x .>> ws) (y .>> ws) (z .>> ws) f
  
  /// Parses an identifier.
  let parseIdentifier = many1Chars2 (pchar '_' <|> asciiLetter)
                                    (pchar '_' <|> asciiLetter <|> digit)
  
  
  // Bracket parsers.
  
negative.code:     parseBinaryExpressionLevel parseAndExpression
          [ ("||", Or) ]
  
  do parseExpressionRef := parseOrExpression <?> "expression"
  
  
  (*
  