Metamath Proof Explorer


Theorem xpv

Description: Cartesian product of a class and the universe. (Contributed by Peter Mazsa, 6-Oct-2020)

Ref Expression
Assertion xpv A × V = x y | x A

Proof

Step Hyp Ref Expression
1 df-xp A × V = x y | x A y V
2 vex y V
3 iba y V x A x A y V
4 2 3 ax-mp x A x A y V
5 4 opabbii x y | x A = x y | x A y V
6 1 5 eqtr4i A × V = x y | x A