Metamath Proof Explorer


Theorem opabssxp

Description: An abstraction relation is a subset of a related Cartesian product. (Contributed by NM, 16-Jul-1995)

Ref Expression
Assertion opabssxp xy|xAyBφA×B

Proof

Step Hyp Ref Expression
1 simpl xAyBφxAyB
2 1 ssopab2i xy|xAyBφxy|xAyB
3 df-xp A×B=xy|xAyB
4 2 3 sseqtrri xy|xAyBφA×B