Metamath Proof Explorer


Theorem brrelex12i

Description: Two classes that are related by a binary relation are sets. Inference form. (Contributed by BJ, 3-Oct-2022)

Ref Expression
Hypothesis brrelexi.1 Rel R
Assertion brrelex12i A R B A V B V

Proof

Step Hyp Ref Expression
1 brrelexi.1 Rel R
2 brrelex12 Rel R A R B A V B V
3 1 2 mpan A R B A V B V