This is the answer. A minus B corresponds to 3, because this is all the elements that are in A but not B. We haven’t filled in this area. A or B is number 2. All of the elements are either in A or B. A & B is number 1. I filled in this middle area corresponding to both sets. The symmetric difference of A and B is 4. All the elements that are in A or B but not in both, and I’ve left out this region. Okay, so now that you understand the basics of set theory, we can implement this in Python.