def test_condition_simple():
rl = rewriterule(x, x+1, [x], lambda x: x < 10)
assert not list(rl(S(15)))
assert rebuild(next(rl(S(5)))) == 6
def test_rebuild():
from sympy import Add
expr = Basic.__new__(Add, 1, 2)
assert rebuild(expr) == 3
