>>> from so2_levels import under_threshold

>>> under_threshold([10.3, 11.5, 10, 11, 12.1], 9.5)
False
>>> under_threshold([10.3, 11.5, 10, 11, 12.1], 12)
True
>>> under_threshold([10.3, -1, 11.5, 10, -2, 11, 12.1], 9.5)
False