def test_d2(self):
rho = qu.eye(2) / 2
psi = qu.purify(rho)
assert qu.expec(psi, qu.bell_state('phi+')) > 1 - 1e-14
def test_pure(self):
rho = qu.up(qtype='dop')
psi = qu.purify(rho)
assert abs(qu.concurrence(psi)) < 1e-14
def test_d2(self):
rho = eye(2) / 2
psi = purify(rho)
assert expec(psi, bell_state('phi+')) > 1 - 1e-14