Theorem cbvrexcsf 2909

Description: A more general version of cbvrexf 2528 that has no distinct variable restrictions. Changes bound variables using implicit substitution. (Contributed by Andrew Salmon, 13-Jul-2011.) (Proof shortened by Mario Carneiro, 7-Dec-2014.)

Hypotheses

Ref	Expression
cbvralcsf.1	|- F/_ y A
cbvralcsf.2	|- F/_ x B
cbvralcsf.3	|- F/ y ph
cbvralcsf.4	|- F/ x ps
cbvralcsf.5	|- ( x = y -> A = B )
cbvralcsf.6	|- ( x = y -> ( ph <-> ps ) )

Assertion

Ref	Expression
cbvrexcsf	|- ( E. x e. A ph <-> E. y e. B ps )

Proof of Theorem cbvrexcsf

Dummy variables v z are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		nfv 1421	. . . 4 |- F/ z ( x e. A /\ ph )
2		nfcsb1v 2882	. . . . . 6 |- F/_ x [_ z / x ]_ A
3	2	nfcri 2172	. . . . 5 |- F/ x z e. [_ z / x ]_ A
4		nfsbc1v 2782	. . . . 5 |- F/ x [. z / x ]. ph
5	3, 4	nfan 1457	. . . 4 |- F/ x ( z e. [_ z / x ]_ A /\ [. z / x ]. ph )
6		id 19	. . . . . 6 |- ( x = z -> x = z )
7		csbeq1a 2860	. . . . . 6 |- ( x = z -> A = [_ z / x ]_ A )
8	6, 7	eleq12d 2108	. . . . 5 |- ( x = z -> ( x e. A <-> z e. [_ z / x ]_ A ) )
9		sbceq1a 2773	. . . . 5 |- ( x = z -> ( ph <-> [. z / x ]. ph ) )
10	8, 9	anbi12d 442	. . . 4 |- ( x = z -> ( ( x e. A /\ ph ) <-> ( z e. [_ z / x ]_ A /\ [. z / x ]. ph ) ) )
11	1, 5, 10	cbvex 1639	. . 3 |- ( E. x ( x e. A /\ ph ) <-> E. z ( z e. [_ z / x ]_ A /\ [. z / x ]. ph ) )
12		nfcv 2178	. . . . . . 7 |- F/_ y z
13		cbvralcsf.1	. . . . . . 7 |- F/_ y A
14	12, 13	nfcsb 2884	. . . . . 6 |- F/_ y [_ z / x ]_ A
15	14	nfcri 2172	. . . . 5 |- F/ y z e. [_ z / x ]_ A
16		cbvralcsf.3	. . . . . 6 |- F/ y ph
17	12, 16	nfsbc 2784	. . . . 5 |- F/ y [. z / x ]. ph
18	15, 17	nfan 1457	. . . 4 |- F/ y ( z e. [_ z / x ]_ A /\ [. z / x ]. ph )
19		nfv 1421	. . . 4 |- F/ z ( y e. B /\ ps )
20		id 19	. . . . . 6 |- ( z = y -> z = y )
21		csbeq1 2855	. . . . . . 7 |- ( z = y -> [_ z / x ]_ A = [_ y / x ]_ A )
22		df-csb 2853	. . . . . . . 8 |- [_ y / x ]_ A = { v | [. y / x ]. v e. A }
23		cbvralcsf.2	. . . . . . . . . . . 12 |- F/_ x B
24	23	nfcri 2172	. . . . . . . . . . 11 |- F/ x v e. B
25		cbvralcsf.5	. . . . . . . . . . . 12 |- ( x = y -> A = B )
26	25	eleq2d 2107	. . . . . . . . . . 11 |- ( x = y -> ( v e. A <-> v e. B ) )
27	24, 26	sbie 1674	. . . . . . . . . 10 |- ( [ y / x ] v e. A <-> v e. B )
28		sbsbc 2768	. . . . . . . . . 10 |- ( [ y / x ] v e. A <-> [. y / x ]. v e. A )
29	27, 28	bitr3i 175	. . . . . . . . 9 |- ( v e. B <-> [. y / x ]. v e. A )
30	29	abbi2i 2152	. . . . . . . 8 |- B = { v | [. y / x ]. v e. A }
31	22, 30	eqtr4i 2063	. . . . . . 7 |- [_ y / x ]_ A = B
32	21, 31	syl6eq 2088	. . . . . 6 |- ( z = y -> [_ z / x ]_ A = B )
33	20, 32	eleq12d 2108	. . . . 5 |- ( z = y -> ( z e. [_ z / x ]_ A <-> y e. B ) )
34		dfsbcq 2766	. . . . . 6 |- ( z = y -> ( [. z / x ]. ph <-> [. y / x ]. ph ) )
35		sbsbc 2768	. . . . . . 7 |- ( [ y / x ] ph <-> [. y / x ]. ph )
36		cbvralcsf.4	. . . . . . . 8 |- F/ x ps
37		cbvralcsf.6	. . . . . . . 8 |- ( x = y -> ( ph <-> ps ) )
38	36, 37	sbie 1674	. . . . . . 7 |- ( [ y / x ] ph <-> ps )
39	35, 38	bitr3i 175	. . . . . 6 |- ( [. y / x ]. ph <-> ps )
40	34, 39	syl6bb 185	. . . . 5 |- ( z = y -> ( [. z / x ]. ph <-> ps ) )
41	33, 40	anbi12d 442	. . . 4 |- ( z = y -> ( ( z e. [_ z / x ]_ A /\ [. z / x ]. ph ) <-> ( y e. B /\ ps ) ) )
42	18, 19, 41	cbvex 1639	. . 3 |- ( E. z ( z e. [_ z / x ]_ A /\ [. z / x ]. ph ) <-> E. y ( y e. B /\ ps ) )
43	11, 42	bitri 173	. 2 |- ( E. x ( x e. A /\ ph ) <-> E. y ( y e. B /\ ps ) )
44		df-rex 2312	. 2 |- ( E. x e. A ph <-> E. x ( x e. A /\ ph ) )
45		df-rex 2312	. 2 |- ( E. y e. B ps <-> E. y ( y e. B /\ ps ) )
46	43, 44, 45	3bitr4i 201	1 |- ( E. x e. A ph <-> E. y e. B ps )

Syntax hints:   -> wi 4   /\ wa 97   <-> wb 98   = wceq 1243   F/wnf 1349   E.wex 1381   e. wcel 1393   [wsb 1645   {cab 2026   F/_wnfc 2165   E.wrex 2307   [.wsbc 2764   [_csb 2852

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-io 630  ax-5 1336  ax-7 1337  ax-gen 1338  ax-ie1 1382  ax-ie2 1383  ax-8 1395  ax-10 1396  ax-11 1397  ax-i12 1398  ax-bndl 1399  ax-4 1400  ax-17 1419  ax-i9 1423  ax-ial 1427  ax-i5r 1428  ax-ext 2022

This theorem depends on definitions:  df-bi 110  df-tru 1246  df-nf 1350  df-sb 1646  df-clab 2027  df-cleq 2033  df-clel 2036  df-nfc 2167  df-rex 2312  df-sbc 2765  df-csb 2853

This theorem is referenced by:  cbvrexv2  2913