def test_ldescent():
# Equations which have solutions
u = ([(13, 23), (3, -11), (41, -113), (4, -7), (-7, 4), (91, -3), (1, 1),
(1, -1), (4, 32), (17, 13), (123689, 1), (19, -570)])
for a, b in u:
w, x, y = ldescent(a, b)
assert a * x**2 + b * y**2 == w**2
assert ldescent(-1, -1) is None
def test_ldescent():
# Equations which have solutions
u = ([(13, 23), (3, -11), (41, -113), (4, -7), (-7, 4), (91, -3), (1, 1), (1, -1),
(4, 32), (17, 13), (123689, 1), (19, -570)])
for a, b in u:
w, x, y = ldescent(a, b)
assert a*x**2 + b*y**2 == w**2
assert ldescent(-1, -1) is None