Metamath Proof Explorer


Definition df-symdif

Description: Define the symmetric difference of two classes. Alternate definitions are dfsymdif2 , dfsymdif3 and dfsymdif4 . (Contributed by Scott Fenton, 31-Mar-2012)

Ref Expression
Assertion df-symdif A B = A B B A

Detailed syntax breakdown

Step Hyp Ref Expression
0 cA class A
1 cB class B
2 0 1 csymdif class A B
3 0 1 cdif class A B
4 1 0 cdif class B A
5 3 4 cun class A B B A
6 2 5 wceq wff A B = A B B A