Theorem ralxfrd 4391

Description: Transfer universal quantification from a variable x to another variable y contained in expression A. (Contributed by NM, 15-Aug-2014.) (Proof shortened by Mario Carneiro, 19-Nov-2016.)

Hypotheses

Ref	Expression
ralxfrd.1	|- ( ( ph /\ y e. C ) -> A e. B )
ralxfrd.2	|- ( ( ph /\ x e. B ) -> E. y e. C x = A )
ralxfrd.3	|- ( ( ph /\ x = A ) -> ( ps <-> ch ) )

Assertion

Ref	Expression
ralxfrd	|- ( ph -> ( A. x e. B ps <-> A. y e. C ch ) )

Distinct variable groups:   x, A   x, y, B   x, C   ch, x   ph, x, y   ps, y

Allowed substitution hints:   ps( x)   ch( y)   A( y)   C( y)

Proof of Theorem ralxfrd

Step	Hyp	Ref	Expression
1		ralxfrd.1	. . . 4 |- ( ( ph /\ y e. C ) -> A e. B )
2		ralxfrd.3	. . . . 5 |- ( ( ph /\ x = A ) -> ( ps <-> ch ) )
3	2	adantlr 469	. . . 4 |- ( ( ( ph /\ y e. C ) /\ x = A ) -> ( ps <-> ch ) )
4	1, 3	rspcdv 2796	. . 3 |- ( ( ph /\ y e. C ) -> ( A. x e. B ps -> ch ) )
5	4	ralrimdva 2515	. 2 |- ( ph -> ( A. x e. B ps -> A. y e. C ch ) )
6		ralxfrd.2	. . . 4 |- ( ( ph /\ x e. B ) -> E. y e. C x = A )
7		r19.29 2572	. . . . 5 |- ( ( A. y e. C ch /\ E. y e. C x = A ) -> E. y e. C ( ch /\ x = A ) )
8	2	biimprd 157	. . . . . . . . 9 |- ( ( ph /\ x = A ) -> ( ch -> ps ) )
9	8	expimpd 361	. . . . . . . 8 |- ( ph -> ( ( x = A /\ ch ) -> ps ) )
10	9	ancomsd 267	. . . . . . 7 |- ( ph -> ( ( ch /\ x = A ) -> ps ) )
11	10	ad2antrr 480	. . . . . 6 |- ( ( ( ph /\ x e. B ) /\ y e. C ) -> ( ( ch /\ x = A ) -> ps ) )
12	11	rexlimdva 2552	. . . . 5 |- ( ( ph /\ x e. B ) -> ( E. y e. C ( ch /\ x = A ) -> ps ) )
13	7, 12	syl5 32	. . . 4 |- ( ( ph /\ x e. B ) -> ( ( A. y e. C ch /\ E. y e. C x = A ) -> ps ) )
14	6, 13	mpan2d 425	. . 3 |- ( ( ph /\ x e. B ) -> ( A. y e. C ch -> ps ) )
15	14	ralrimdva 2515	. 2 |- ( ph -> ( A. y e. C ch -> A. x e. B ps ) )
16	5, 15	impbid 128	1 |- ( ph -> ( A. x e. B ps <-> A. y e. C ch ) )

Syntax hints:   -> wi 4   /\ wa 103   <-> wb 104   = wceq 1332   e. wcel 1481   A.wral 2417   E.wrex 2418

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-ral 2422  df-rex 2423  df-v 2691

This theorem is referenced by:  ralxfr2d  4393  ralxfr  4395