Definition:Symmetric Difference/Definition 1

Definition
The symmetric difference between two sets $S$ and $T$ is written $S * T$ and is defined as:
 * $S * T := \left({S \setminus T}\right) \cup \left({T \setminus S}\right)$

where:
 * $\setminus$ denotes set difference
 * $\cup$ denotes set union.

Also see

 * Equivalence of Definitions of Symmetric Difference