There's something wrong with problem 4 in Lesson 9. The problem reads:
Set bool_four equal to the result of not not True or False and not True
I came up with False, which it says is wrong. When I look at the hint, it says:
True or not False and False. not gets evaluated first, so we have
True or True and False.
But the hint doesn't match the problem! It has a not in the wrong place.