I'm having trouble figuring this out so I'd appreciate any help you can offer.

DESIRED SITUATION:

The player needs to use a lift to exit the area. However, the power to that section is offline. The lights are out, and the lift button is inoperative. Nearby there are two power generators. When both buttons are pressed (not simultaneously), the generators activate (func_rotating etc.), the lights come on and the lift button is now operative.

I believe the env_global entity is used in conjunction with multisource and multimanager entities, but the specifics escape me, despite attempting to modify tutorials regarding the env_global to suit my purposes. Since I can't find a tutorial specific to this situation, I thought here would be the next best place.