def test_issue_4099():
    a = Symbol('a')
    assert limit(a/x, x, 0) == oo*sign(a)
    assert limit(-a/x, x, 0) == -oo*sign(a)
    assert limit(-a*x, x, oo) == -oo*sign(a)
    assert limit(a*x, x, oo) == oo*sign(a)
dataset/ETHPy150Open sympy/sympy/sympy/series/tests/test_limits.py/test_issue_4099/original