static function Action_add(&$app, $type, PHP_ParserGenerator_Symbol $sp, $arg)
    {
        $new = new PHP_ParserGenerator_Action;
        $new->next = $app;
        $app = $new;
        $new->type = $type;
        $new->sp = $sp;
        $new->x = $arg;
        echo ' Adding ';
        $new->display();
    }