public void Test_is_symmetric() { var binaryRelation = new Set<Tuple<int, int>> { new Tuple<int, int>(1, 1), new Tuple<int, int>(1, 2) }; binaryRelation.IsSymmetric().ShouldBeFalse(); binaryRelation.Add(new Tuple<int, int>(2, 1)); binaryRelation.IsSymmetric().ShouldBeTrue(); binaryRelation.IsEquivalenceRelation().ShouldBeFalse(); }