anchor.diff:  
   terms
   	: nil
  -	| inner_term ( COMMA! terms | nil )
  +	| term ( COMMA! terms | nil )
   		{ ## = #(#[COMMA,","], ##) }	
   	| STAR^ opt_wildcard
   	;
   	
   opt_wildcard
  -	: inner_term
  +	: term
   	|
   		{ ## = #(#[WILDCARD,"_"]) }	
   	;
  
positive.code: grammar
  	: 
  		( docstring )? 
  		( part )* 
  		EOF!
  	;
  
  part
  	: HEADER^ ACTION
  	| 
  		CLASS^ id ( LPAREN! id RPAREN! )? COLON!
  		( docstring )?
  		( method )*
  	;
  
  method
  	: ACTION
  	| rule
  	;
  
  rule
  
negative.code: class wgenLexer extends Lexer;
  
  options {
  	k = 3;
  	testLiterals = false;
  }
  
  