Metamath Proof Explorer


Theorem issetssr

Description: Two ways of expressing set existence. (Contributed by Peter Mazsa, 1-Aug-2019)

Ref Expression
Assertion issetssr A V A S A

Proof

Step Hyp Ref Expression
1 brssrid A V A S A
2 relssr Rel S
3 2 brrelex1i A S A A V
4 1 3 impbii A V A S A