def test_issue_4199():
    # first subs and limit gives NaN
    a = x/y
    assert a._eval_interval(x, 0, oo)._eval_interval(y, oo, 0) is S.NaN
    # second subs and limit gives NaN
    assert a._eval_interval(x, 0, oo)._eval_interval(y, 0, oo) is S.NaN
    # difference gives S.NaN
    a = x - y
    assert a._eval_interval(x, 1, oo)._eval_interval(y, oo, 1) is S.NaN
    raises(ValueError, lambda: x._eval_interval(x, None, None))
    a = -y*Heaviside(x - y)
    assert a._eval_interval(x, -oo, oo) == -y
    assert a._eval_interval(x, oo, -oo) == y
dataset/ETHPy150Open sympy/sympy/sympy/core/tests/test_expr.py/test_issue_4199/original