Definition:Symmetric Difference/Definition 5

Definition
Let $S$ and $T$ be any two sets.

The symmetric difference of $S$ and $T$ is the set which consists of all the elements which are contained in either $S$ or $T$ but not both:
 * $S * T := set {x: x \in S \oplus x \in T}$

where $\oplus$ denotes the exclusive or connective.

Also see

 * Equivalence of Definitions of Symmetric Difference