# Singleton Set (Definition, Symbol, and Example)

## Definition of Singleton Set

A Singleton Set or Unit Set is a set having exactly one element. In other words, a set $A$ is said to be a Singleton Set if the cardinality of the set is 1 i.e., $$\displaystyle n(A)=1$$

## Singleton set Symbol

Let a Singleton Set $A$ has only one element that is $2$. Then, it can be written as:

$A$ = {2}

## Singleton Set Example

1. $\displaystyle A={x:x\in N,x<2}$
2. $\displaystyle A={x:x\,\,is\,prime\,number,x<3}$
3. $\displaystyle A={x:x\,is\,integer\,,\,-2