Step |
Hyp |
Ref |
Expression |
1 |
|
dfima2 |
|- ( F " A ) = { y | E. x e. A x F y } |
2 |
|
ssel |
|- ( A C_ dom F -> ( x e. A -> x e. dom F ) ) |
3 |
|
funbrfvb |
|- ( ( Fun F /\ x e. dom F ) -> ( ( F ` x ) = y <-> x F y ) ) |
4 |
3
|
ex |
|- ( Fun F -> ( x e. dom F -> ( ( F ` x ) = y <-> x F y ) ) ) |
5 |
2 4
|
syl9r |
|- ( Fun F -> ( A C_ dom F -> ( x e. A -> ( ( F ` x ) = y <-> x F y ) ) ) ) |
6 |
5
|
imp31 |
|- ( ( ( Fun F /\ A C_ dom F ) /\ x e. A ) -> ( ( F ` x ) = y <-> x F y ) ) |
7 |
6
|
rexbidva |
|- ( ( Fun F /\ A C_ dom F ) -> ( E. x e. A ( F ` x ) = y <-> E. x e. A x F y ) ) |
8 |
7
|
abbidv |
|- ( ( Fun F /\ A C_ dom F ) -> { y | E. x e. A ( F ` x ) = y } = { y | E. x e. A x F y } ) |
9 |
1 8
|
eqtr4id |
|- ( ( Fun F /\ A C_ dom F ) -> ( F " A ) = { y | E. x e. A ( F ` x ) = y } ) |