Description: Membership of an ordere pair in a class abstraction of ordered pairs. (Contributed by BJ, 17-Dec-2023)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | opelopabd.xph | |- ( ph -> A. x ph ) | |
| opelopabd.yph | |- ( ph -> A. y ph ) | ||
| opelopabd.xch | |- ( ph -> F/ x ch ) | ||
| opelopabd.ych | |- ( ph -> F/ y ch ) | ||
| opelopabd.exa | |- ( ph -> A e. U ) | ||
| opelopabd.exb | |- ( ph -> B e. V ) | ||
| opelopabd.is | |- ( ( ph /\ ( x = A /\ y = B ) ) -> ( ps <-> ch ) ) | ||
| Assertion | opelopabd | |- ( ph -> ( <. A , B >. e. { <. x , y >. | ps } <-> ch ) ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | opelopabd.xph | |- ( ph -> A. x ph ) | |
| 2 | opelopabd.yph | |- ( ph -> A. y ph ) | |
| 3 | opelopabd.xch | |- ( ph -> F/ x ch ) | |
| 4 | opelopabd.ych | |- ( ph -> F/ y ch ) | |
| 5 | opelopabd.exa | |- ( ph -> A e. U ) | |
| 6 | opelopabd.exb | |- ( ph -> B e. V ) | |
| 7 | opelopabd.is | |- ( ( ph /\ ( x = A /\ y = B ) ) -> ( ps <-> ch ) ) | |
| 8 | elopab |  |-  ( <. A , B >. e. { <. x , y >. | ps } <-> E. x E. y ( <. A , B >. = <. x , y >. /\ ps ) ) | |
| 9 | 1 2 3 4 5 6 7 | copsex2d | |- ( ph -> ( E. x E. y ( <. A , B >. = <. x , y >. /\ ps ) <-> ch ) ) | 
| 10 | 8 9 | bitrid |  |-  ( ph -> ( <. A , B >. e. { <. x , y >. | ps } <-> ch ) ) |