Description: An abstraction relation is a subset of a related Cartesian product. (Contributed by NM, 16-Jul-1995)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | opabssxp | |- { <. x , y >. | ( ( x e. A /\ y e. B ) /\ ph ) } C_ ( A X. B ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | simpl | |- ( ( ( x e. A /\ y e. B ) /\ ph ) -> ( x e. A /\ y e. B ) ) |
|
| 2 | 1 | ssopab2i | |- { <. x , y >. | ( ( x e. A /\ y e. B ) /\ ph ) } C_ { <. x , y >. | ( x e. A /\ y e. B ) } |
| 3 | df-xp | |- ( A X. B ) = { <. x , y >. | ( x e. A /\ y e. B ) } |
|
| 4 | 2 3 | sseqtrri | |- { <. x , y >. | ( ( x e. A /\ y e. B ) /\ ph ) } C_ ( A X. B ) |