anchor.diff:  	;
   
   id returns [ret]
  -	: u:CONS { ret = #u.getText() }
  -	| l:VAR { ret = #l.getText() }
  -	| d:TRANSF { ret = #d.getText() }
  +	: i:ID { ret = #i.getText() }
   	;
   
   method
  
positive.code:     : ('a'..'z') ('a'..'z'|'A'..'Z'|'0'..'9'|'_')* 
      ;
  
  TRANSF
  	:
  		':'! 
  
negative.code: 	;
  
  id
  	: c:CONS { #c.setType(ID) }
  	| v:VAR { #v.setType(ID) }
  	| ID
  	;
  
  
  