Player 2
                            L         R
                    T （-1, 4）（ 1, 5）
Player 1
                    B  （0, 2） （-1, 0）

Assume that the game  have to be undertaken simultaneously，and it is  repeated an infinite number of times. Let δ be
the discount factor. What are all the SPE (in pure strategies) if δ tends to 0? What are all the SPE (in pure strategies) if δ tends to 1?