anchor.diff:  fragment
   BinaryExponentIndicator
       :   [pP]
  +    ;
  +
  +fragment
  +Dot :   '.'
       ;
   
   // §3.10.3 Boolean Literals
  
positive.code: 
  fragment
  BinaryNumeral
      :   '0' [bB] BinaryDigits
      ;
  
  fragment
  
negative.code: 
  fragment
  DecimalFloatingPointLiteral
      :   Digits Dot Digits ExponentPart? FloatTypeSuffix?
      |   Digits ExponentPart FloatTypeSuffix?
      |   Digits FloatTypeSuffix
      ;
  