Rule AlphaFilter() {
        return Sequence(
                Sequence(
                        "alpha(", Ws0(),
                        "opacity", Ws0(),
                        '=', Ws0(),
                        Digit1(), Ws0(),
                        ')'
                ),
                push(new SimpleNode(match()))
        );
    }
Rule AlphaFilter() {
        return Sequence(
                Sequence(
                        "alpha(", Ws0(),
                        "opacity", Ws0(),
                        '=', Ws0(),
                        Digit1(), Ws0(),
                        ')'
                ),
                push(new SimpleNode(match()))
        );
    }
Rule AlphaFilter ( ) { return Sequence ( Sequence ( "alpha(" , Ws0 ( ) , "opacity" , Ws0 ( ) , ' ' , Ws0 ( ) , Digit1 ( ) , Ws0 ( ) , ' ' ) , push ( new SimpleNode ( match ( ) ) ) ) ; }
'alpha(' Ws0 'opacity' Ws0 '=' Ws0 Digit1 Ws0 ')'
alpha ( Ws0 opacity Ws0 = Ws0 Digit1 Ws0 )