Foundations of Mathematics

Set Theory

What are open and closed sets?

Formally, an open set is one in which every element in the set has a neighbor in the set or does not include its boundary. A closed set is one that does include a boundary of a set, or one where some elements have neighbors not in the set.



Close

This is a web preview of the "The Handy Math Answer Book" app. Many features only work on your mobile device. If you like what you see, we hope you will consider buying. Get the App