Step |
Hyp |
Ref |
Expression |
1 |
|
mpteq12df.1 |
|- F/ x ph |
2 |
|
mpteq12df.2 |
|- ( ph -> A = C ) |
3 |
|
mpteq12df.3 |
|- ( ph -> B = D ) |
4 |
|
nfv |
|- F/ y ph |
5 |
2
|
eleq2d |
|- ( ph -> ( x e. A <-> x e. C ) ) |
6 |
3
|
eqeq2d |
|- ( ph -> ( y = B <-> y = D ) ) |
7 |
5 6
|
anbi12d |
|- ( ph -> ( ( x e. A /\ y = B ) <-> ( x e. C /\ y = D ) ) ) |
8 |
1 4 7
|
opabbid |
|- ( ph -> { <. x , y >. | ( x e. A /\ y = B ) } = { <. x , y >. | ( x e. C /\ y = D ) } ) |
9 |
|
df-mpt |
|- ( x e. A |-> B ) = { <. x , y >. | ( x e. A /\ y = B ) } |
10 |
|
df-mpt |
|- ( x e. C |-> D ) = { <. x , y >. | ( x e. C /\ y = D ) } |
11 |
8 9 10
|
3eqtr4g |
|- ( ph -> ( x e. A |-> B ) = ( x e. C |-> D ) ) |