Set Theory Explained

A detailed tutorial of set theory. Step by step tutorial including several examples of set theory for reference. Knowledge of set theory is required for most upper level math classes.

Set theory is the practice of sets and subsets. A set is a group of elements – numbers, items, anything. A set is expressed as A = {1, 2, 3, 4}, with A being the set, and anything inside the brackets being part of the set, being elements. A subset is also a set, but one that is the same as or contains part of another set. Each set has at least two subsets, because a subset can also be the exact same set, and an empty set. An empty set is expressed as a O with a line drawn through it, and it is a set that has no elements in it.