+ G = random_orthant_game()
+ self.assert_solutions_dont_change(G)
+
+ def test_solutions_dont_change_icecream(self):
+ """
+ If we solve the same game twice over the ice-cream cone, then we
+ should get the same solution both times. The solution to a game
+ is not unique, but the process we use is (as far as we know)
+ deterministic.
+ """
+ G = random_icecream_game()
+ self.assert_solutions_dont_change(G)
+
+ def assert_solutions_dont_change(self, G):
+ """
+ Solve ``G`` twice and check that the solutions agree.
+ """
+ soln1 = G.solution()
+ soln2 = G.solution()
+ p1_diff = norm(soln1.player1_optimal() - soln2.player1_optimal())
+ p2_diff = norm(soln1.player2_optimal() - soln2.player2_optimal())
+ gv_diff = abs(soln1.game_value() - soln2.game_value())