anchor.diff:  
   // GRAMMAR OF OPERATORS
   
  -operator : operator_character operator? ;
  -Operator_character : [/=\-+!*%<>&|^!.] ;
  -binary_operator : operator  ;
  -prefix_operator : operator  ;
  -postfix_operator : operator  ;
  +Operator : Operator_character+ ;
  +fragment Operator_character : [/=\-+!*%<>&|^!.] ;
  +binary_operator : Operator ;
  +prefix_operator : Operator  ;
  +postfix_operator : Operator  ;
   
   // Types
   
  
positive.code:  | Identifier_head
   ;
  
  fragment Identifier_characters : Identifier_character Identifier_characters? ;
  
  Implicit_parameter_name : '$' Decimal_digits  ;
  
  // GRAMMAR OF A LITERAL
  
  literal : integer_literal | floating_point_literal | string_literal  ;
  
  // GRAMMAR OF AN INTEGER LITERAL
  
  
negative.code:  | [\u00BC-\u00BE] | [\u00C0-\u00D6] | [\u00D8-\u00F6] | [\u00F8-\u00FF]
   | [\u0100-\u02FF] | [\u0370-\u167F] | [\u1681-\u180D] | [\u180F-\u1DBF]
   | [\u1E00-\u1FFF]
   | [\u200B-\u200D] | [\u202A-\u202E] | [\u203F-\u2040] | '\u2054' | [\u2060-\u206F]
   | [\u2070-\u20CF] | [\u2100-\u218F] | [\u2460-\u24FF] | [\u2776-\u2793]
   | [\u2C00-\u2DFF] | [\u2E80-\u2FFF]
   | [\u3004-\u3007] | [\u3021-\u302F] | [\u3031-\u303F] | [\u3040-\uD7FF]
   | [\uF900-\uFD3D] | [\uFD40-\uFDCF] | [\uFDF0-\uFE1F] | [\uFE30-\uFE44]
   | [\uFE47-\uFFFD]
  