User:Dfeuer/Definition:Empty Class

Definition

The empty class, denoted $\varnothing$, is the class with the property that:

$\forall x: \lnot (x \in \varnothing)$

Also known as

In light of the User:Dfeuer/Axiom of the Empty Set, the empty class is also called the empty set or the null set.

Also see

• User:Dfeuer/Empty Class Exists and is Unique