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 ) |