"""
(L, K, e1, e2) = _random_icecream_params()
self.assert_opposite_game_works(L, K, e1, e2)
+
+
+ def assert_orthogonality(self, L, K, e1, e2):
+ """
+ Two orthogonality relations hold at an optimal solution, and we
+ check them here.
+ """
+ game = SymmetricLinearGame(L, K, e1, e2)
+ soln = game.solution()
+ x_bar = soln.player1_optimal()
+ y_bar = soln.player2_optimal()
+ value = soln.game_value()
+
+ # Make these matrices so that we can compute with them.
+ L = matrix(L).trans()
+ e1 = matrix(e1, (K.dimension(), 1))
+ e2 = matrix(e2, (K.dimension(), 1))
+
+ ip1 = inner_product(y_bar, L*x_bar - value*e1)
+ self.assert_within_tol(ip1, 0)
+
+ ip2 = inner_product(value*e2 - L.trans()*y_bar, x_bar)
+ self.assert_within_tol(ip2, 0)
+
+
+ def test_orthogonality_orthant(self):
+ """
+ Check the orthgonality relationships that hold for a solution
+ over the nonnegative orthant.
+ """
+ (L, K, e1, e2) = _random_orthant_params()
+ self.assert_orthogonality(L, K, e1, e2)
+
+
+ def test_orthogonality_icecream(self):
+ """
+ Check the orthgonality relationships that hold for a solution
+ over the ice-cream cone.
+ """
+ (L, K, e1, e2) = _random_icecream_params()
+ self.assert_orthogonality(L, K, e1, e2)
+
+
+ def test_positive_operator_value(self):
+ """
+ Test that a positive operator on the nonnegative orthant gives
+ rise to a a game with a nonnegative value.
+
+ This test theoretically applies to the ice-cream cone as well,
+ but we don't know how to make positive operators on that cone.
+ """
+ (L, K, e1, e2) = _random_orthant_params()
+
+ # Make the entries of ``L`` nonnegative... this makes it a
+ # positive operator on ``K``.
+ L = [[abs(entry) for entry in row] for row in L]
+
+ game = SymmetricLinearGame(L, K, e1, e2)
+ self.assertTrue(game.solution().game_value() >= -options.ABS_TOL)