Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - start with the Axiom of Extensionality
The difference, union, and intersection of two classes
The symmetric difference of two classes
df-symdif
Metamath Proof Explorer
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