public Parser greaterOrEqualOp() {
        if (greaterOrEqualOpParser == null) {
           FutureParser future = scoped("greaterOrEqualOp");
           greaterOrEqualOpParser = future;
           future.setParser(
               choice(
                   sequence(
                       token("GREATER"),
                       optional(
                           token("THAN")
                       ),
                       token("OR"),
                       token("EQUAL"),
                       optional(
                           token("TO")
                       )
                   ),
                   token(">=")
               )
           );
        }

        return greaterOrEqualOpParser;
    }