Metamath Proof Explorer


Theorem epel

Description: The membership relation and the membership predicate agree when the "containing" class is a setvar. (Contributed by NM, 13-Aug-1995) Replace the first setvar variable with a class variable. (Revised by BJ, 13-Sep-2022)

Ref Expression
Assertion epel
|- ( A _E x <-> A e. x )

Proof

Step Hyp Ref Expression
1 vex
 |-  x e. _V
2 1 epeli
 |-  ( A _E x <-> A e. x )