def test_eq_ne(self):
"Test Signomial equality and inequality operators"
x = Variable('x')
xu = Variable('x', units="ft")
with SignomialsEnabled():
self.assertEqual(x - x**2, -x**2 + x)
if gpkit.units:
self.assertNotEqual(-x, -xu)
else: # units don't create inequality if they're disabled
self.assertEqual(-x, -xu)
# numeric
self.assertEqual(Signomial(0), 0)
self.assertNotEqual(Signomial(0), 1)
self.assertEqual(Signomial(-3), -3)
self.assertNotEqual(Signomial(-3), 3)