Theorem elabf 2831

Description: Membership in a class abstraction, using implicit substitution. (Contributed by NM, 1-Aug-1994.) (Revised by Mario Carneiro, 12-Oct-2016.)

Hypotheses

Ref	Expression
elabf.1	|- F/ x ps
elabf.2	|- A e. _V
elabf.3	|- ( x = A -> ( ph <-> ps ) )

Assertion

Ref	Expression
elabf	|- ( A e. { x | ph } <-> ps )

Distinct variable group:   x, A

Allowed substitution hints:   ph( x)   ps( x)

Proof of Theorem elabf

Step	Hyp	Ref	Expression
1		elabf.2	. 2 |- A e. _V
2		nfcv 2282	. . 3 |- F/_ x A
3		elabf.1	. . 3 |- F/ x ps
4		elabf.3	. . 3 |- ( x = A -> ( ph <-> ps ) )
5	2, 3, 4	elabgf 2830	. 2 |- ( A e. _V -> ( A e. { x | ph } <-> ps ) )
6	1, 5	ax-mp 5	1 |- ( A e. { x | ph } <-> ps )

Syntax hints:   -> wi 4   <-> wb 104   = wceq 1332   F/wnf 1437   e. wcel 1481   {cab 2126   _Vcvv 2689

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-io 699  ax-5 1424  ax-7 1425  ax-gen 1426  ax-ie1 1470  ax-ie2 1471  ax-8 1483  ax-10 1484  ax-11 1485  ax-i12 1486  ax-bndl 1487  ax-4 1488  ax-17 1507  ax-i9 1511  ax-ial 1515  ax-i5r 1516  ax-ext 2122

This theorem depends on definitions:  df-bi 116  df-tru 1335  df-nf 1438  df-sb 1737  df-clab 2127  df-cleq 2133  df-clel 2136  df-nfc 2271  df-v 2691

This theorem is referenced by:  elab  2832  indpi  7174