Consider the game represented by the game tree below. The
first mover, Player 1, may move either Up or Down, after which Player 2 may
move either Left or Right. Payoffs for the possible outcomes appear below.
Reexpress this game in strategic (table) form. Find all of the pure-strategy
Nash equilibria in the game. If there are multiple equilibria, indicate which
one is subgame-perfect. For those equilibria that are not subgame-perfect,
identify the reason (the source of the lack of credibility).