2. (16 pts.) Problem solving Consider the problem of solving two 8-puzzles. (a) (6) Give a complete problem formulation. (b) (4) How large is the reachable state space? (Give an exact numerical expression; no need to calculate its value.) (c) (2) Suppose we make the problem adversarial as follows: the two players take turns moving; a coin is flipped to determine the puzzle on which to make a move in that turn; and the winner is the first to solve one puzzle. Which algorithm can be used to choose a move in this setting? (d) (4) Give an informal proof that someone will eventually win if both play perfectly