Symmetric difference

In set theory, the symmetric difference of two sets A and B is the set of elements either in A or in B but not in both.

Definition
Given two sets A and B, $A \Delta B = \{ x\|x \in A \oplus x \in B \}$

Example[]

Suppose A = {1,3,5,7,9} and B = {1,2,3,4,5}:

A \Delta B = \{ 2,4,7,9 \}