- 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.
Thumbnail: Overlapping sets. (CC BY-SA 3.0 Unported; Chris-martin via Wikipedia).