Some special subsets of the Real Numbers

Venn Diagrams

Venn diagrams are a convenient way to illustrate definitions related to sets.

An introduction to Venn diagrams and sets may be found here.

A very clever interactive demonstration using Venn diagrams to show various properties of set union, intersection and complement may be found here. Move your cursor over the various names around the outside of the rectangle and watch the set show up in color.