Theorem cbvopab1 4117

Description: Change first bound variable in an ordered-pair class abstraction, using explicit substitution. (Contributed by NM, 6-Oct-2004.) (Revised by Mario Carneiro, 14-Oct-2016.)

Hypotheses

Ref	Expression
cbvopab1.1	|- F/ z ph
cbvopab1.2	|- F/ x ps
cbvopab1.3	|- ( x = z -> ( ph <-> ps ) )

Assertion

Ref	Expression
cbvopab1	|- { <. x , y >. | ph } = { <. z , y >. | ps }

Distinct variable groups:   x, y   y, z

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

Proof of Theorem cbvopab1

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

Step	Hyp	Ref	Expression
1		nfv 1551	. . . . 5 |- F/ v E. y ( w = <. x , y >. /\ ph )
2		nfv 1551	. . . . . . 7 |- F/ x w = <. v , y >.
3		nfs1v 1967	. . . . . . 7 |- F/ x [ v / x ] ph
4	2, 3	nfan 1588	. . . . . 6 |- F/ x ( w = <. v , y >. /\ [ v / x ] ph )
5	4	nfex 1660	. . . . 5 |- F/ x E. y ( w = <. v , y >. /\ [ v / x ] ph )
6		opeq1 3819	. . . . . . . 8 |- ( x = v -> <. x , y >. = <. v , y >. )
7	6	eqeq2d 2217	. . . . . . 7 |- ( x = v -> ( w = <. x , y >. <-> w = <. v , y >. ) )
8		sbequ12 1794	. . . . . . 7 |- ( x = v -> ( ph <-> [ v / x ] ph ) )
9	7, 8	anbi12d 473	. . . . . 6 |- ( x = v -> ( ( w = <. x , y >. /\ ph ) <-> ( w = <. v , y >. /\ [ v / x ] ph ) ) )
10	9	exbidv 1848	. . . . 5 |- ( x = v -> ( E. y ( w = <. x , y >. /\ ph ) <-> E. y ( w = <. v , y >. /\ [ v / x ] ph ) ) )
11	1, 5, 10	cbvex 1779	. . . 4 |- ( E. x E. y ( w = <. x , y >. /\ ph ) <-> E. v E. y ( w = <. v , y >. /\ [ v / x ] ph ) )
12		nfv 1551	. . . . . . 7 |- F/ z w = <. v , y >.
13		cbvopab1.1	. . . . . . . 8 |- F/ z ph
14	13	nfsb 1974	. . . . . . 7 |- F/ z [ v / x ] ph
15	12, 14	nfan 1588	. . . . . 6 |- F/ z ( w = <. v , y >. /\ [ v / x ] ph )
16	15	nfex 1660	. . . . 5 |- F/ z E. y ( w = <. v , y >. /\ [ v / x ] ph )
17		nfv 1551	. . . . 5 |- F/ v E. y ( w = <. z , y >. /\ ps )
18		opeq1 3819	. . . . . . . 8 |- ( v = z -> <. v , y >. = <. z , y >. )
19	18	eqeq2d 2217	. . . . . . 7 |- ( v = z -> ( w = <. v , y >. <-> w = <. z , y >. ) )
20		sbequ 1863	. . . . . . . 8 |- ( v = z -> ( [ v / x ] ph <-> [ z / x ] ph ) )
21		cbvopab1.2	. . . . . . . . 9 |- F/ x ps
22		cbvopab1.3	. . . . . . . . 9 |- ( x = z -> ( ph <-> ps ) )
23	21, 22	sbie 1814	. . . . . . . 8 |- ( [ z / x ] ph <-> ps )
24	20, 23	bitrdi 196	. . . . . . 7 |- ( v = z -> ( [ v / x ] ph <-> ps ) )
25	19, 24	anbi12d 473	. . . . . 6 |- ( v = z -> ( ( w = <. v , y >. /\ [ v / x ] ph ) <-> ( w = <. z , y >. /\ ps ) ) )
26	25	exbidv 1848	. . . . 5 |- ( v = z -> ( E. y ( w = <. v , y >. /\ [ v / x ] ph ) <-> E. y ( w = <. z , y >. /\ ps ) ) )
27	16, 17, 26	cbvex 1779	. . . 4 |- ( E. v E. y ( w = <. v , y >. /\ [ v / x ] ph ) <-> E. z E. y ( w = <. z , y >. /\ ps ) )
28	11, 27	bitri 184	. . 3 |- ( E. x E. y ( w = <. x , y >. /\ ph ) <-> E. z E. y ( w = <. z , y >. /\ ps ) )
29	28	abbii 2321	. 2 |- { w | E. x E. y ( w = <. x , y >. /\ ph ) } = { w | E. z E. y ( w = <. z , y >. /\ ps ) }
30		df-opab 4106	. 2 |- { <. x , y >. | ph } = { w | E. x E. y ( w = <. x , y >. /\ ph ) }
31		df-opab 4106	. 2 |- { <. z , y >. | ps } = { w | E. z E. y ( w = <. z , y >. /\ ps ) }
32	29, 30, 31	3eqtr4i 2236	1 |- { <. x , y >. | ph } = { <. z , y >. | ps }

Syntax hints:   -> wi 4   /\ wa 104   <-> wb 105   = wceq 1373   F/wnf 1483   E.wex 1515   [wsb 1785   {cab 2191   <.cop 3636   {copab 4104

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-io 711  ax-5 1470  ax-7 1471  ax-gen 1472  ax-ie1 1516  ax-ie2 1517  ax-8 1527  ax-10 1528  ax-11 1529  ax-i12 1530  ax-bndl 1532  ax-4 1533  ax-17 1549  ax-i9 1553  ax-ial 1557  ax-i5r 1558  ax-ext 2187

This theorem depends on definitions:  df-bi 117  df-3an 983  df-tru 1376  df-nf 1484  df-sb 1786  df-clab 2192  df-cleq 2198  df-clel 2201  df-nfc 2337  df-v 2774  df-un 3170  df-sn 3639  df-pr 3640  df-op 3642  df-opab 4106

This theorem is referenced by:  cbvopab1v  4120  cbvmptf  4138  cbvmpt  4139