def test_diff0():
ns = NameSpace(1)
x = ns.Symbol('x')
expr = (3 * x)
deriv = expr.diff(x)
ref = ns.Number(3)
assert (deriv == ref) is True
assert (-x).diff(x) == ns.Number(-1)
def test_factor():
ns = NameSpace()
fortytwo = ns.Number(42)
factors = ns.factor(fortytwo)
ref = ns.mul(2, 3, 7)
assert ref == factors
def test_compare_numbers():
ns = NameSpace()
three, four = ns.Number(3), ns.Number(4)
lt = three < four
assert lt.evalb() is True
