Section 3.1
Section 3.1 covers the basics of set theory. It is not important to memorize all of the axioms that appear in this section. Instead, your goal should be to gain familiarity with how sets are used, by working out the exercises at the end of the section and doing more math in general. The cards below will drill you a bit on some of the notation and terminology. Once you get used to sets, they should feel very easy to you.