anchor.diff:  
   fragment
   HexadecimalFloatingConstant
  -    :   HexadecimalPrefix HexadecimalFractionalConstant BinaryExponentPart FloatingSuffix?
  -    |   HexadecimalPrefix HexadecimalDigitSequence BinaryExponentPart FloatingSuffix?
  +    :   HexadecimalPrefix (HexadecimalFractionalConstant | HexadecimalDigitSequence) BinaryExponentPart FloatingSuffix?
       ;
   
   fragment
  
positive.code: 
  fragment
  OctalEscapeSequence
      :   '\\' OctalDigit
      |   '\\' OctalDigit OctalDigit
      |   '\\' OctalDigit OctalDigit OctalDigit
      ;
  
  fragment
  
negative.code: 
  fragment
  BinaryExponentPart
      :   [pP] Sign? DigitSequence
      ;
  
  fragment
  