If not B then A 6. Give me an example of an A sentence and its contradictory. It didn't matter whether you gave me the letters or actual words, both got marks. Some classes are not challenging, because All classes are boring, and some boring things are not challenging. The easiest way to evaluate this is with a venn diagram.
All classes are boring means that the 'classes' circle goes inside the 'boring' circle.
So far, so good. Here's where many of you went wrong. Most people who remembered to do this agreed that it was common knowledge that 'all classes are boring' is false. That is enough for you to conclude that this is a bad argument. Books are printed documents designed to entertain.