Good. Which is really the question in all of this. Finding good heuristics. And the

solution I'm, and so that we had two things we talked about. One is actually

different heuristics actually matter as we can see via these numbers. And we can

find good heuristics by cheating. Just relaxing the problem, which is just what

cheating is. And so if we solve a relaxed problem instead of the original

problem, we get to the solutions faster. And the result of those searches might

actually be a good heuristic depending on how much we cheat. So the wonderful

thing here is if we relax the problem and use the real solution to the relaxed

problem as a heuristic to the original problem, then we're underestimating

automatically. This gives us admissible heuristics automatically. Why? Because any

solution to the real problem is also a solution to the relaxed problem. So we're

underestimating. So this is a good way of doing it. And if you don't know how to

cheat, learn how to cheat. Okay? It gives you good heuristics. And sometimes the

relaxed problem is still too difficult to solve. Then you need to cheat more. Okay.

Who of you looked at this? You should. It gives you very good intuitions about

search. And it's much better than counting sheep in certain

situations. I think you should really look at it. Just looking at this

little snake of where you're all going and so on and what you've searched and

how often you search these things, it actually tells you a lot about what

search is. So it has a depth-first search, a breadth-first search, an A star search

for various heuristics setting. And you can just play with them a little bit. You

don't have to look, you shouldn't actually for certain things wait until

it found, it actually found a solution because that takes too long. In some

cases too long for the server that this runs on to exist or you to exist or

whatever. But look at that. Really do it. It gives you an intuition. By the way,

we're probably going to start game search or politely expressed

adversarial search, right? Solving problems by game, solving games where you

have an adversary by search and building chess systems or so. Where these

kind of things matter because it's just a kind of search on steroids where you

have an uncontrolled environment. But many of the intuitions still apply.

you