I argue it out in my head first. I have to, he's pretty clever and if I don't find all the loopholes and all of the angles he can manipulate then I get caught between a rock and a hard place.
That sounds really bad. It's not. It's just he's a really bright guy and I have to always be on my toes. Arguing with him is something I actually enjoy doing, most of the time. We've only had one or two really huge blow outs.