def test_unfiy_tricky():
v1 = qvar()
v2 = qvar()
g1 = qfun(v1, v2)
g2 = qfun(v2, qobj())
assert_equal(unify([g1, g2]), qfun(qobj(), qobj()))
def test_unify():
assert_raises(UnificationError, unify, [qobj(), qbool()])
assert_equal(unify([qobj(), qobj()]), qobj())
assert_equal(unify([qvar(), qobj()]), qobj())
assert_equal(unify([qobj(), qvar()]), qobj())
v1 = qvar()
v2 = qvar()
uni = unify([v1, v2])
assert_true(uni == v1 or uni == v2)
f1 = qfun(qobj(), qbool())
f2 = qfun(qobj(), qobj())
f3 = qfun(qvar(), qobj())
f4 = qfun(qvar(), qvar())
assert_raises(UnificationError, unify, [f1, f2])
assert_equal(unify([f2, f3]), f2)
assert_equal(unify([f2, f4]), f2)
assert_equal(unify([f3, f4]), f3)
