Theorem elssabg 4127

Description: Membership in a class abstraction involving a subset. Unlike elabg 2872, A does not have to be a set. (Contributed by NM, 29-Aug-2006.)

Hypothesis

Ref	Expression
elssabg.1	|- ( x = A -> ( ph <-> ps ) )

Assertion

Ref	Expression
elssabg	|- ( B e. V -> ( A e. { x | ( x C_ B /\ ph ) } <-> ( A C_ B /\ ps ) ) )

Distinct variable groups:   x, A   x, B   ps, x

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

Proof of Theorem elssabg

Step	Hyp	Ref	Expression
1		ssexg 4121	. . . 4 |- ( ( A C_ B /\ B e. V ) -> A e. _V )
2	1	expcom 115	. . 3 |- ( B e. V -> ( A C_ B -> A e. _V ) )
3	2	adantrd 277	. 2 |- ( B e. V -> ( ( A C_ B /\ ps ) -> A e. _V ) )
4		sseq1 3165	. . . 4 |- ( x = A -> ( x C_ B <-> A C_ B ) )
5		elssabg.1	. . . 4 |- ( x = A -> ( ph <-> ps ) )
6	4, 5	anbi12d 465	. . 3 |- ( x = A -> ( ( x C_ B /\ ph ) <-> ( A C_ B /\ ps ) ) )
7	6	elab3g 2877	. 2 |- ( ( ( A C_ B /\ ps ) -> A e. _V ) -> ( A e. { x | ( x C_ B /\ ph ) } <-> ( A C_ B /\ ps ) ) )
8	3, 7	syl 14	1 |- ( B e. V -> ( A e. { x | ( x C_ B /\ ph ) } <-> ( A C_ B /\ ps ) ) )

Syntax hints:   -> wi 4   /\ wa 103   <-> wb 104   = wceq 1343   e. wcel 2136   {cab 2151   _Vcvv 2726   C_ wss 3116

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 1435  ax-7 1436  ax-gen 1437  ax-ie1 1481  ax-ie2 1482  ax-8 1492  ax-10 1493  ax-11 1494  ax-i12 1495  ax-bndl 1497  ax-4 1498  ax-17 1514  ax-i9 1518  ax-ial 1522  ax-i5r 1523  ax-ext 2147  ax-sep 4100

This theorem depends on definitions:  df-bi 116  df-tru 1346  df-nf 1449  df-sb 1751  df-clab 2152  df-cleq 2158  df-clel 2161  df-nfc 2297  df-v 2728  df-in 3122  df-ss 3129

This theorem is referenced by: (None)