| Step |
Hyp |
Ref |
Expression |
| 1 |
|
fmptdF.p |
|- F/ x ph |
| 2 |
|
fmptdF.a |
|- F/_ x A |
| 3 |
|
fmptdF.c |
|- F/_ x C |
| 4 |
|
fmptdF.1 |
|- ( ( ph /\ x e. A ) -> B e. C ) |
| 5 |
|
fmptdF.2 |
|- F = ( x e. A |-> B ) |
| 6 |
4
|
sbimi |
|- ( [ y / x ] ( ph /\ x e. A ) -> [ y / x ] B e. C ) |
| 7 |
|
sban |
|- ( [ y / x ] ( ph /\ x e. A ) <-> ( [ y / x ] ph /\ [ y / x ] x e. A ) ) |
| 8 |
1
|
sbf |
|- ( [ y / x ] ph <-> ph ) |
| 9 |
2
|
clelsb1fw |
|- ( [ y / x ] x e. A <-> y e. A ) |
| 10 |
8 9
|
anbi12i |
|- ( ( [ y / x ] ph /\ [ y / x ] x e. A ) <-> ( ph /\ y e. A ) ) |
| 11 |
7 10
|
bitri |
|- ( [ y / x ] ( ph /\ x e. A ) <-> ( ph /\ y e. A ) ) |
| 12 |
|
sbsbc |
|- ( [ y / x ] B e. C <-> [. y / x ]. B e. C ) |
| 13 |
|
sbcel12 |
|- ( [. y / x ]. B e. C <-> [_ y / x ]_ B e. [_ y / x ]_ C ) |
| 14 |
|
vex |
|- y e. _V |
| 15 |
14 3
|
csbgfi |
|- [_ y / x ]_ C = C |
| 16 |
15
|
eleq2i |
|- ( [_ y / x ]_ B e. [_ y / x ]_ C <-> [_ y / x ]_ B e. C ) |
| 17 |
13 16
|
bitri |
|- ( [. y / x ]. B e. C <-> [_ y / x ]_ B e. C ) |
| 18 |
12 17
|
bitri |
|- ( [ y / x ] B e. C <-> [_ y / x ]_ B e. C ) |
| 19 |
6 11 18
|
3imtr3i |
|- ( ( ph /\ y e. A ) -> [_ y / x ]_ B e. C ) |
| 20 |
19
|
ralrimiva |
|- ( ph -> A. y e. A [_ y / x ]_ B e. C ) |
| 21 |
|
nfcv |
|- F/_ y A |
| 22 |
|
nfcv |
|- F/_ y B |
| 23 |
|
nfcsb1v |
|- F/_ x [_ y / x ]_ B |
| 24 |
|
csbeq1a |
|- ( x = y -> B = [_ y / x ]_ B ) |
| 25 |
2 21 22 23 24
|
cbvmptf |
|- ( x e. A |-> B ) = ( y e. A |-> [_ y / x ]_ B ) |
| 26 |
25
|
fmpt |
|- ( A. y e. A [_ y / x ]_ B e. C <-> ( x e. A |-> B ) : A --> C ) |
| 27 |
20 26
|
sylib |
|- ( ph -> ( x e. A |-> B ) : A --> C ) |
| 28 |
5
|
feq1i |
|- ( F : A --> C <-> ( x e. A |-> B ) : A --> C ) |
| 29 |
27 28
|
sylibr |
|- ( ph -> F : A --> C ) |