anchor.diff:  	
   primexpr
   	:	literal
  -//	|	typename postf_op*
  +	|	postf_op
   	;
   	
   postf_op
  -	:	'.' var_or_type
  -	|	'[' expr ']'
  +	:	(ID -> ID) ('.' nm=ID -> ^('.' $postf_op $nm)
  +	|	'[' e=expr ']' -> ^('[' $postf_op $e))*
   	;	
   
   	
  
positive.code: 	;
  	
  var_decl
  	:	'var'^ var_init (','! var_init)*	
  	;		
  	
  var_init
  
negative.code: 	|	ID '=' expr		-> ^(ID ^('=' expr))
  	;
  	
  var_or_type_dot
  	:	ID^ ('.'! var_or_type_dot)?
  	;
  
  typename
  	:	var_or_type_dot
  	|	'strong' '[' typename ']'
  	|	'weak' '[' typename ']'
  	|	'ptr' '[' typename ']'
  