anchor.diff:  		|	OR
   		)
   		expression	# BinaryExpression
  -	|	(NormalIdentifier | PropertyIdentifier) 
  +	|	<assoc=right> expression QUESTION expression COLON expression		# TernaryOpExpression
  +	|	<assoc=right> (NormalIdentifier | PropertyIdentifier) 
   		Operator=(
   			ASSIGN
   		|	MUL_ASSIGN 
  
positive.code: 		|	SUB_ASSIGN
  		)
  		expression  # AssignmentExpression
  	|	NormalIdentifier parExpressionList		# FunctionCallExpression
  	;
  	
  /*
  
negative.code: MUL			: '*';
  DIV			: '/';
  MOD         : '%';
  QUESTION	: '?';
  COLON		: ':';
  EQUAL		: '==';
  LE			: '<=';
  GE			: '>=';
  