anchor.diff:  	| XorAssign
   	| AndAssign
   	| OrAssign
  -	| LeftShift
  -	| RightShift
  +	| (Less Less)
  +	| (Greater Greater)
   	| RightShiftAssign
   	| LeftShiftAssign
   	| Equal
  
positive.code: 	| Tilde
  	| Not
  	| Assign
  	| Less
  	| GreaterEqual
  	| PlusAssign
  
negative.code: 	| ArrowStar
  	| Arrow
  	| LeftParen RightParen
  	| LeftBracket RightBracket;
  
  literal:
  	IntegerLiteral
  	| CharacterLiteral
  	| FloatingLiteral
  	| StringLiteral
  	| BooleanLiteral
  	| PointerLiteral
  	| UserDefinedLiteral;
  