Description: Restricted converse epsilon relation as a class of ordered pairs. (Contributed by Peter Mazsa, 10-Feb-2018)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | cnvepres | |- ( `' _E |` A ) = { <. x , y >. | ( x e. A /\ y e. x ) } |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | dfres2 | |- ( `' _E |` A ) = { <. x , y >. | ( x e. A /\ x `' _E y ) } |
|
| 2 | brcnvep | |- ( x e. _V -> ( x `' _E y <-> y e. x ) ) |
|
| 3 | 2 | elv | |- ( x `' _E y <-> y e. x ) |
| 4 | 3 | anbi2i | |- ( ( x e. A /\ x `' _E y ) <-> ( x e. A /\ y e. x ) ) |
| 5 | 4 | opabbii | |- { <. x , y >. | ( x e. A /\ x `' _E y ) } = { <. x , y >. | ( x e. A /\ y e. x ) } |
| 6 | 1 5 | eqtri | |- ( `' _E |` A ) = { <. x , y >. | ( x e. A /\ y e. x ) } |