Theorem cbvabw 2319

Description: Version of cbvab 2320 with a disjoint variable condition. (Contributed by GG, 10-Jan-2024.) Reduce axiom usage. (Revised by GG, 25-Aug-2024.)

Hypotheses

Ref	Expression
cbvabw.1	|- F/ y ph
cbvabw.2	|- F/ x ps
cbvabw.3	|- ( x = y -> ( ph <-> ps ) )

Assertion

Ref	Expression
cbvabw	|- { x | ph } = { y | ps }

Distinct variable group:   x, y

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

Proof of Theorem cbvabw

Dummy variable z is distinct from all other variables.

Step	Hyp	Ref	Expression
1		cbvabw.1	. . . . . 6 |- F/ y ph
2	1	nfsbv 1966	. . . . 5 |- F/ y [ z / x ] ph
3		equequ2 1727	. . . . . . . 8 |- ( y = z -> ( x = y <-> x = z ) )
4	3	imbi1d 231	. . . . . . 7 |- ( y = z -> ( ( x = y -> ph ) <-> ( x = z -> ph ) ) )
5	4	albidv 1838	. . . . . 6 |- ( y = z -> ( A. x ( x = y -> ph ) <-> A. x ( x = z -> ph ) ) )
6		sb6 1901	. . . . . 6 |- ( [ y / x ] ph <-> A. x ( x = y -> ph ) )
7		sb6 1901	. . . . . 6 |- ( [ z / x ] ph <-> A. x ( x = z -> ph ) )
8	5, 6, 7	3bitr4g 223	. . . . 5 |- ( y = z -> ( [ y / x ] ph <-> [ z / x ] ph ) )
9	2, 8	sbiev 1806	. . . 4 |- ( [ z / y ] [ y / x ] ph <-> [ z / x ] ph )
10		cbvabw.2	. . . . . 6 |- F/ x ps
11		cbvabw.3	. . . . . 6 |- ( x = y -> ( ph <-> ps ) )
12	10, 11	sbiev 1806	. . . . 5 |- ( [ y / x ] ph <-> ps )
13	12	sbbii 1779	. . . 4 |- ( [ z / y ] [ y / x ] ph <-> [ z / y ] ps )
14	9, 13	bitr3i 186	. . 3 |- ( [ z / x ] ph <-> [ z / y ] ps )
15		df-clab 2183	. . 3 |- ( z e. { x | ph } <-> [ z / x ] ph )
16		df-clab 2183	. . 3 |- ( z e. { y | ps } <-> [ z / y ] ps )
17	14, 15, 16	3bitr4i 212	. 2 |- ( z e. { x | ph } <-> z e. { y | ps } )
18	17	eqriv 2193	1 |- { x | ph } = { y | ps }

Syntax hints:   -> wi 4   <-> wb 105   A.wal 1362   = wceq 1364   F/wnf 1474   [wsb 1776   e. wcel 2167   {cab 2182

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-5 1461  ax-7 1462  ax-gen 1463  ax-ie1 1507  ax-ie2 1508  ax-8 1518  ax-11 1520  ax-4 1524  ax-17 1540  ax-i9 1544  ax-ial 1548  ax-i5r 1549  ax-ext 2178

This theorem depends on definitions:  df-bi 117  df-nf 1475  df-sb 1777  df-clab 2183  df-cleq 2189

This theorem is referenced by:  cbvsbcw  3017