Description: Membership in an ordered-pair class abstraction defined by a restricted binary relation. (Contributed by AV, 16-Feb-2021)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | elopabran | |- ( A e. { <. x , y >. | ( x R y /\ ps ) } -> A e. R ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | simpl | |- ( ( x R y /\ ps ) -> x R y ) | |
| 2 | 1 | ssopab2i |  |-  { <. x , y >. | ( x R y /\ ps ) } C_ { <. x , y >. | x R y } | 
| 3 | opabss |  |-  { <. x , y >. | x R y } C_ R | |
| 4 | 2 3 | sstri |  |-  { <. x , y >. | ( x R y /\ ps ) } C_ R | 
| 5 | 4 | sseli |  |-  ( A e. { <. x , y >. | ( x R y /\ ps ) } -> A e. R ) |