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 ) u. ( B \ A ) )

Detailed syntax breakdown

Step Hyp Ref Expression
0 cA
 |-  A
1 cB
 |-  B
2 0 1 csymdif
 |-  ( A /_\ B )
3 0 1 cdif
 |-  ( A \ B )
4 1 0 cdif
 |-  ( B \ A )
5 3 4 cun
 |-  ( ( A \ B ) u. ( B \ A ) )
6 2 5 wceq
 |-  ( A /_\ B ) = ( ( A \ B ) u. ( B \ A ) )