def test_entanglement(self, p):
rho = werner_state(p)
assert concurrence(rho) > 1e-14
def test_extremes(self):
p = werner_state(1)
assert_allclose(p, bell_state('psi-', qtype='dop'))
p = werner_state(0)
assert_allclose(p, eye(4) / 4, atol=1e-14)