anchor.diff:  class parser extends Parser;
   
   options {
  +	k = 2;
   	defaultErrorHandler = false;
   }
   
  
positive.code: 		)?
  	;
  
  term_list returns [res]
  	:
  		{ res = self.handleNil() }
  	| head=term
  		( COMMA tail=term_list
  		|
  			{ tail = self.handleNil() }
  		)
  			{ res = self.handleCons(head, tail) }
  	| STAR
  		(
  			{ res = self.handleWildcard() }
  		| vname:VAR
  			{ res = self.handleVar(vname.getText()) }
  		)
  	;
  
  
negative.code: 			{ res = [] }
  	| arg=term
  			{ res = [arg] }
  		( COMMA arg=term
  			{ res.append(arg) }
  		)*
  	;
  