| Step |
Hyp |
Ref |
Expression |
| 1 |
|
elcoeleqvrels |
|- ( A e. V -> ( A e. CoElEqvRels <-> ,~ ( `' _E |` A ) e. EqvRels ) ) |
| 2 |
|
1cosscnvepresex |
|- ( A e. V -> ,~ ( `' _E |` A ) e. _V ) |
| 3 |
|
eleqvrelsrel |
|- ( ,~ ( `' _E |` A ) e. _V -> ( ,~ ( `' _E |` A ) e. EqvRels <-> EqvRel ,~ ( `' _E |` A ) ) ) |
| 4 |
2 3
|
syl |
|- ( A e. V -> ( ,~ ( `' _E |` A ) e. EqvRels <-> EqvRel ,~ ( `' _E |` A ) ) ) |
| 5 |
1 4
|
bitrd |
|- ( A e. V -> ( A e. CoElEqvRels <-> EqvRel ,~ ( `' _E |` A ) ) ) |
| 6 |
|
df-coeleqvrel |
|- ( CoElEqvRel A <-> EqvRel ,~ ( `' _E |` A ) ) |
| 7 |
5 6
|
bitr4di |
|- ( A e. V -> ( A e. CoElEqvRels <-> CoElEqvRel A ) ) |