| Step |
Hyp |
Ref |
Expression |
| 1 |
|
disjimeldisjdmqs |
|- ( Disj R -> ElDisj ( dom R /. R ) ) |
| 2 |
|
eldisjsdisj |
|- ( R e. Disjs -> ( R e. Disjs <-> Disj R ) ) |
| 3 |
|
dmqsex |
|- ( R e. Disjs -> ( dom R /. R ) e. _V ) |
| 4 |
|
eleldisjseldisj |
|- ( ( dom R /. R ) e. _V -> ( ( dom R /. R ) e. ElDisjs <-> ElDisj ( dom R /. R ) ) ) |
| 5 |
3 4
|
syl |
|- ( R e. Disjs -> ( ( dom R /. R ) e. ElDisjs <-> ElDisj ( dom R /. R ) ) ) |
| 6 |
2 5
|
imbi12d |
|- ( R e. Disjs -> ( ( R e. Disjs -> ( dom R /. R ) e. ElDisjs ) <-> ( Disj R -> ElDisj ( dom R /. R ) ) ) ) |
| 7 |
1 6
|
mpbiri |
|- ( R e. Disjs -> ( R e. Disjs -> ( dom R /. R ) e. ElDisjs ) ) |
| 8 |
7
|
pm2.43i |
|- ( R e. Disjs -> ( dom R /. R ) e. ElDisjs ) |