public void Xor_ReturnsExclusiveDisjunction() { var spec1 = new IntegerGreaterThanZero(); var spec2 = new IntegerLessThanZero(); var conjoinedSpec = spec1.Xor(spec2); Assert.That(conjoinedSpec, Is.TypeOf<ExclusiveDisjunction<int>>()); Assert.That(conjoinedSpec, Has.Property("Left").EqualTo(spec1)); Assert.That(conjoinedSpec, Has.Property("Right").EqualTo(spec2)); }