 Contingency reversal is just basically mess with you drastically. That's what they do. I don't know, folks. This is a really, really easy one. Think of two behaviors, right? So one behavior produces reinforcers, another behavior produces extinction. This is just an example, right? So if we want to do a contingency reversal, we take the behavior that once produced reinforcers and put it on extinction, and the behavior that used to produce extinction, maybe two, now put that one where it produces a certain number of reinforcers. You're reversing the contingencies. It creates a situation where you can get behavior change to occur rather drastically. Sometimes quickly, sometimes not, based on the learning history of the organism, based on the behavioral momentum, so on and so forth. But basically, it's just, it's a bugger. It can, wow, it can hurt. You'll understand when you go through it some days, like, that was always working, and now it doesn't, and what didn't work in the past now does. Ah, it's life changing. Ask anyone that's over about 70. What a contingency reversal is, my guess is they'll have some experiences.