Definition:Singleton Class

Definition
Let $a$ be a set.

The class $\set a$ is a singleton (class).

It can be referred to as singleton $a$.

Also known as
Singleton $a$ can also be referred to as bracket $a$, but singleton $a$ is preferred, as it is less ambiguous.

Also see

 * Singleton Class can be Formed from Set


 * Definition:Singleton