def test_exp(): a = exp(interval(-np.inf, 0)) assert a.start == np.exp(-np.inf) assert a.end == np.exp(0) a = exp(interval(1, 2)) assert a.start == np.exp(1) assert a.end == np.exp(2) a = exp(1) assert a.start == np.exp(1) assert a.end == np.exp(1)