Metamath Proof Explorer


Theorem elab4g

Description: Membership in a class abstraction, using implicit substitution. (Contributed by NM, 17-Oct-2012)

Ref Expression
Hypotheses elab4g.1
|- ( x = A -> ( ph <-> ps ) )
elab4g.2
|- B = { x | ph }
Assertion elab4g
|- ( A e. B <-> ( A e. _V /\ ps ) )

Proof

Step Hyp Ref Expression
1 elab4g.1
 |-  ( x = A -> ( ph <-> ps ) )
2 elab4g.2
 |-  B = { x | ph }
3 elex
 |-  ( A e. B -> A e. _V )
4 1 2 elab2g
 |-  ( A e. _V -> ( A e. B <-> ps ) )
5 3 4 biadanii
 |-  ( A e. B <-> ( A e. _V /\ ps ) )