=+7.7. In "progress and pinch," the wager, initially some integer, is increased by 1 after a loss and decreased by 1 after a win, the stopping rule being to quit if the next bet is 0. Show that play is certain to terminate if and only if p 2 ;. Show that F. - F0 + =W2 + }(7 - 1). Infinite capital is required.