def test_acosh(): a = acosh(interval(3, 5)) assert a.start == np.arccosh(3) assert a.end == np.arccosh(5) a = acosh(interval(0, 3)) assert a.is_valid is None a = acosh(interval(-3, 0.5)) assert a.is_valid is False a = acosh(0.5) assert a.is_valid is False a = acosh(2) assert a.start == np.arccosh(2) assert a.end == np.arccosh(2)