Metamath Proof Explorer


Theorem elom3

Description: A simplification of elom assuming the Axiom of Infinity. (Contributed by NM, 30-May-2003)

Ref Expression
Assertion elom3
|- ( A e. _om <-> A. x ( Lim x -> A e. x ) )

Proof

Step Hyp Ref Expression
1 elom
 |-  ( A e. _om <-> ( A e. On /\ A. x ( Lim x -> A e. x ) ) )
2 limom
 |-  Lim _om
3 omex
 |-  _om e. _V
4 limeq
 |-  ( x = _om -> ( Lim x <-> Lim _om ) )
5 eleq2
 |-  ( x = _om -> ( A e. x <-> A e. _om ) )
6 4 5 imbi12d
 |-  ( x = _om -> ( ( Lim x -> A e. x ) <-> ( Lim _om -> A e. _om ) ) )
7 3 6 spcv
 |-  ( A. x ( Lim x -> A e. x ) -> ( Lim _om -> A e. _om ) )
8 2 7 mpi
 |-  ( A. x ( Lim x -> A e. x ) -> A e. _om )
9 nnon
 |-  ( A e. _om -> A e. On )
10 8 9 syl
 |-  ( A. x ( Lim x -> A e. x ) -> A e. On )
11 10 pm4.71ri
 |-  ( A. x ( Lim x -> A e. x ) <-> ( A e. On /\ A. x ( Lim x -> A e. x ) ) )
12 1 11 bitr4i
 |-  ( A e. _om <-> A. x ( Lim x -> A e. x ) )