Description: Membership in an ordered-pair class abstraction. One can remove the DV condition on x , y by using opabid in place of opabidw . (Contributed by BJ, 22-May-2024)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | bj-opelopabid | |- ( x { <. x , y >. | ph } y <-> ph ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | df-br | |- ( x { <. x , y >. | ph } y <-> <. x , y >. e. { <. x , y >. | ph } ) |
|
| 2 | opabidw | |- ( <. x , y >. e. { <. x , y >. | ph } <-> ph ) |
|
| 3 | 1 2 | bitri | |- ( x { <. x , y >. | ph } y <-> ph ) |