| Step |
Hyp |
Ref |
Expression |
| 1 |
|
opex |
|- <. A , B >. e. _V |
| 2 |
|
setsvalg |
|- ( ( S e. V /\ <. A , B >. e. _V ) -> ( S sSet <. A , B >. ) = ( ( S |` ( _V \ dom { <. A , B >. } ) ) u. { <. A , B >. } ) ) |
| 3 |
1 2
|
mpan2 |
|- ( S e. V -> ( S sSet <. A , B >. ) = ( ( S |` ( _V \ dom { <. A , B >. } ) ) u. { <. A , B >. } ) ) |
| 4 |
3
|
reseq1d |
|- ( S e. V -> ( ( S sSet <. A , B >. ) |` ( _V \ { A } ) ) = ( ( ( S |` ( _V \ dom { <. A , B >. } ) ) u. { <. A , B >. } ) |` ( _V \ { A } ) ) ) |
| 5 |
|
resundir |
|- ( ( ( S |` ( _V \ dom { <. A , B >. } ) ) u. { <. A , B >. } ) |` ( _V \ { A } ) ) = ( ( ( S |` ( _V \ dom { <. A , B >. } ) ) |` ( _V \ { A } ) ) u. ( { <. A , B >. } |` ( _V \ { A } ) ) ) |
| 6 |
|
dmsnopss |
|- dom { <. A , B >. } C_ { A } |
| 7 |
|
sscon |
|- ( dom { <. A , B >. } C_ { A } -> ( _V \ { A } ) C_ ( _V \ dom { <. A , B >. } ) ) |
| 8 |
6 7
|
ax-mp |
|- ( _V \ { A } ) C_ ( _V \ dom { <. A , B >. } ) |
| 9 |
|
resabs1 |
|- ( ( _V \ { A } ) C_ ( _V \ dom { <. A , B >. } ) -> ( ( S |` ( _V \ dom { <. A , B >. } ) ) |` ( _V \ { A } ) ) = ( S |` ( _V \ { A } ) ) ) |
| 10 |
8 9
|
ax-mp |
|- ( ( S |` ( _V \ dom { <. A , B >. } ) ) |` ( _V \ { A } ) ) = ( S |` ( _V \ { A } ) ) |
| 11 |
|
dmres |
|- dom ( { <. A , B >. } |` ( _V \ { A } ) ) = ( ( _V \ { A } ) i^i dom { <. A , B >. } ) |
| 12 |
|
disj2 |
|- ( ( ( _V \ { A } ) i^i dom { <. A , B >. } ) = (/) <-> ( _V \ { A } ) C_ ( _V \ dom { <. A , B >. } ) ) |
| 13 |
8 12
|
mpbir |
|- ( ( _V \ { A } ) i^i dom { <. A , B >. } ) = (/) |
| 14 |
11 13
|
eqtri |
|- dom ( { <. A , B >. } |` ( _V \ { A } ) ) = (/) |
| 15 |
|
relres |
|- Rel ( { <. A , B >. } |` ( _V \ { A } ) ) |
| 16 |
|
reldm0 |
|- ( Rel ( { <. A , B >. } |` ( _V \ { A } ) ) -> ( ( { <. A , B >. } |` ( _V \ { A } ) ) = (/) <-> dom ( { <. A , B >. } |` ( _V \ { A } ) ) = (/) ) ) |
| 17 |
15 16
|
ax-mp |
|- ( ( { <. A , B >. } |` ( _V \ { A } ) ) = (/) <-> dom ( { <. A , B >. } |` ( _V \ { A } ) ) = (/) ) |
| 18 |
14 17
|
mpbir |
|- ( { <. A , B >. } |` ( _V \ { A } ) ) = (/) |
| 19 |
10 18
|
uneq12i |
|- ( ( ( S |` ( _V \ dom { <. A , B >. } ) ) |` ( _V \ { A } ) ) u. ( { <. A , B >. } |` ( _V \ { A } ) ) ) = ( ( S |` ( _V \ { A } ) ) u. (/) ) |
| 20 |
|
un0 |
|- ( ( S |` ( _V \ { A } ) ) u. (/) ) = ( S |` ( _V \ { A } ) ) |
| 21 |
19 20
|
eqtri |
|- ( ( ( S |` ( _V \ dom { <. A , B >. } ) ) |` ( _V \ { A } ) ) u. ( { <. A , B >. } |` ( _V \ { A } ) ) ) = ( S |` ( _V \ { A } ) ) |
| 22 |
5 21
|
eqtri |
|- ( ( ( S |` ( _V \ dom { <. A , B >. } ) ) u. { <. A , B >. } ) |` ( _V \ { A } ) ) = ( S |` ( _V \ { A } ) ) |
| 23 |
4 22
|
eqtrdi |
|- ( S e. V -> ( ( S sSet <. A , B >. ) |` ( _V \ { A } ) ) = ( S |` ( _V \ { A } ) ) ) |