20.10 Extend the standard game-playing environment (Chapter 5) to incorporate a reward signal. Put two reinforcement learning agents into the environment (they may of course share the agent program) and have them play against each other. Apply the generalized TD update rule

(Equation (20.8)) to update the evaluation function. You may wish to start with a simple linear weighted evaluation function, and a simple game such as tic-tac-toe.