Metamath Proof Explorer


Theorem elvv

Description: Membership in universal class of ordered pairs. (Contributed by NM, 4-Jul-1994)

Ref Expression
Assertion elvv AV×VxyA=xy

Proof

Step Hyp Ref Expression
1 elxp AV×VxyA=xyxVyV
2 vex xV
3 vex yV
4 2 3 pm3.2i xVyV
5 4 biantru A=xyA=xyxVyV
6 5 2exbii xyA=xyxyA=xyxVyV
7 1 6 bitr4i AV×VxyA=xy