Hello and welcome to Set Theory: A Bite-Sized Lecture Series! In these videos, you'll get a conceptual overview of set theory that doesn't take all day. In Lesson 9: Axiom of Choice, we'll discuss the basic idea of the axiom of choice and then learn about six different forms of it. Note (7:10): I wrote "Union B subset A" when I meant to write "Union B in A." Link to example problems: Link to folder with all the problem sets: