| Step |
Hyp |
Ref |
Expression |
| 1 |
|
dfrn2 |
|- ran R = { y | E. x x R y } |
| 2 |
|
nfopab2 |
|- F/_ y { <. x , y >. | ph } |
| 3 |
2
|
nfeq2 |
|- F/ y R = { <. x , y >. | ph } |
| 4 |
|
nfopab1 |
|- F/_ x { <. x , y >. | ph } |
| 5 |
4
|
nfeq2 |
|- F/ x R = { <. x , y >. | ph } |
| 6 |
|
df-br |
|- ( x R y <-> <. x , y >. e. R ) |
| 7 |
|
eleq2 |
|- ( R = { <. x , y >. | ph } -> ( <. x , y >. e. R <-> <. x , y >. e. { <. x , y >. | ph } ) ) |
| 8 |
|
opabidw |
|- ( <. x , y >. e. { <. x , y >. | ph } <-> ph ) |
| 9 |
7 8
|
bitrdi |
|- ( R = { <. x , y >. | ph } -> ( <. x , y >. e. R <-> ph ) ) |
| 10 |
6 9
|
bitrid |
|- ( R = { <. x , y >. | ph } -> ( x R y <-> ph ) ) |
| 11 |
5 10
|
exbid |
|- ( R = { <. x , y >. | ph } -> ( E. x x R y <-> E. x ph ) ) |
| 12 |
3 11
|
abbid |
|- ( R = { <. x , y >. | ph } -> { y | E. x x R y } = { y | E. x ph } ) |
| 13 |
1 12
|
eqtrid |
|- ( R = { <. x , y >. | ph } -> ran R = { y | E. x ph } ) |