anchor.diff:      : ('a'..'z') ('a'..'z'|'A'..'Z'|'0'..'9'|'_')* 
       ;
   
  +// Identifiers (CONS and VAR will become IDs too)
  +ID
  +	: '_' ('a'..'z'|'A'..'Z'|'0'..'9'|'_')+
  +	;
  +	
   TRANSF
   	:
   		':'! 
  
positive.code: 	;
  
  id
  	: CONS
  	| VAR
  	;
  
  
  
negative.code: 	;
  
  id returns [ret]
  	: i:ID { ret = #i.getText() }
  	;
  
  method
  