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Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - add the Axiom of Union
Function transposition
df-tpos
Metamath Proof Explorer
Description: Define the transposition of a function, which is a function
G = tpos F satisfying G ( x , y ) = F ( y , x ) . (Contributed by Mario Carneiro , 10-Sep-2015)
Ref
Expression
Assertion
df-tpos
⊢ tpos F = F ∘ x ∈ dom ⁡ F -1 ∪ ∅ ⟼ ⋃ x -1
Detailed syntax breakdown
Step
Hyp
Ref
Expression
0
cF
class F
1
0
ctpos
class tpos F
2
vx
setvar x
3
0
cdm
class dom ⁡ F
4
3
ccnv
class dom ⁡ F -1
5
c0
class ∅
6
5
csn
class ∅
7
4 6
cun
class dom ⁡ F -1 ∪ ∅
8
2
cv
setvar x
9
8
csn
class x
10
9
ccnv
class x -1
11
10
cuni
class ⋃ x -1
12
2 7 11
cmpt
class x ∈ dom ⁡ F -1 ∪ ∅ ⟼ ⋃ x -1
13
0 12
ccom
class F ∘ x ∈ dom ⁡ F -1 ∪ ∅ ⟼ ⋃ x -1
14
1 13
wceq
wff tpos F = F ∘ x ∈ dom ⁡ F -1 ∪ ∅ ⟼ ⋃ x -1