# 4: Sets

- Page ID
- 8406

\( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)

\( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)

- 4.1: An Introduction to Sets
- A set is a collection of objects. The objects in a set are called its elements or members. The elements in a set can be any types of objects, including sets! The members of a set do not even have to be of the same type. For example, although it may not have any meaningful application, a set can consist of numbers and names.

- 4.2: Subsets and Power Sets
- We usually consider sets containing elements of similar types. The collection of all the objects under consideration is called the universal set, and is denoted U.

- 4.3: Unions and Intersections
- We can form a new set from existing sets by carrying out a set operation.