So, in an imperfect-information game, the values of the states of the depth-limit depend on what our policy is, in the earlier parts of the game. So, how do we deal with this? Well, one option is to just actually make the state values dependent on our policy, and say, "Okay. Well, the value of a state is a function of the description of that state, and our policy for the entire game." Well, that is theoretically correct to the promise that's extremely expensive, I mean absurdly expensive. The other option is something called, well,