He wants to learn deeply about set theory.

Set operation is one of the basic concepts in mathematics.

He is learning how to use collective nouns.

In mathematics, an empty set refers to a set that does not contain any elements.

A power set is a set consisting of all subsets of a set.

In math class, we learned about the intersection.

In math class, we learned about the concept of union sets.

There is a communal letterbox in our apartment.

Please refer to the diagram above.

This class diagram shows the overall picture of our project.