[Eventing Question] How to make a Gym Leader fight you in a Double Battle?

I've got the Gym Leader event and Gym ready and set up. I just need to figure out how to make this Gym Leader battle you in a Double Battle. Right now he's only battling me in Single Battle format.

Some scripts in default trainers are comments, and some are Scripts. But the default Gym Leader uses Conditional Branch scripts. How do I change those correctly to make this a double battle?

Here's the method that's being used, so you can see what to put where in the script command (make sure there aren't any comments that will override this):