Symmetric Difference
Definition
Let $A, B \subseteq X$. The symmetric difference of $A$ and $B$ is
$$ A \bigtriangleup B = (A \setminus B) \cup (B \setminus A) $$Let $A, B \subseteq X$. The symmetric difference of $A$ and $B$ is
$$ A \bigtriangleup B = (A \setminus B) \cup (B \setminus A) $$