Untwisty Corridor is a single player game. There are nine propositions - p, q1,..., q8. And there are four action - a, b, c, and d. q1 is true in the initial state, and the goal is to turn on q8. Actions a, b, and c all turn on p. If a qi proposition is true, then action d turns on the next in sequence, provided that p is false; otherwise it does nothing. There is a step counter that terminates the game on step 8.