# Definition:Class Difference

## Definition

Let $A$ and $B$ be two classes.

The (class) difference $A \setminus B$ of $A$ and $B$ is defined as the class of all sets $x$ such that $x \in A$ and $x \notin B$:

$x \in A \setminus B \iff x \in A \land x \notin A$

or:

$A \setminus B = \set {x: x \in A \land x \notin B}$

## Also see

• Results about class difference can be found here.