Theorem dvelimfALT 1153

Description: Proof of dvelimf 1250 without using ax-11 967. See dvelimALT 1353 for a proof (of the distinct variable version dvelim 1352) that doesn't require ax-10 966.

Hypotheses

Ref	Expression
dvelimfALT.1	|- (ph -> A.xph)
dvelimfALT.2	|- (ps -> A.zps)
dvelimfALT.3	|- (z = y -> (ph <-> ps))

Assertion

Ref	Expression
dvelimfALT	|- (-. A.x x = y -> (ps -> A.xps))

Proof of Theorem dvelimfALT

Step	Hyp	Ref	Expression
1		ax-10o 1140	. . . . . 6 |- (A.z z = x -> (A.zA.z(z = y -> ph) -> A.xA.z(z = y -> ph)))
2	1	alequcoms 1143	. . . . 5 |- (A.x x = z -> (A.zA.z(z = y -> ph) -> A.xA.z(z = y -> ph)))
3		hba1 1003	. . . . 5 |- (A.z(z = y -> ph) -> A.zA.z(z = y -> ph))
4	2, 3	syl5 21	. . . 4 |- (A.x x = z -> (A.z(z = y -> ph) -> A.xA.z(z = y -> ph)))
5	4	a1d 12	. . 3 |- (A.x x = z -> (-. A.x x = y -> (A.z(z = y -> ph) -> A.xA.z(z = y -> ph))))
6		hbnae 1147	. . . . . 6 |- (-. A.x x = z -> A.z -. A.x x = z)
7		hbnae 1147	. . . . . 6 |- (-. A.x x = y -> A.z -. A.x x = y)
8	6, 7	hban 1009	. . . . 5 |- ((-. A.x x = z /\ -. A.x x = y) -> A.z(-. A.x x = z /\ -. A.x x = y))
9		hbnae 1147	. . . . . . 7 |- (-. A.x x = z -> A.x -. A.x x = z)
10		hbnae 1147	. . . . . . 7 |- (-. A.x x = y -> A.x -. A.x x = y)
11	9, 10	hban 1009	. . . . . 6 |- ((-. A.x x = z /\ -. A.x x = y) -> A.x(-. A.x x = z /\ -. A.x x = y))
12		ax-12 968	. . . . . . 7 |- (-. A.x x = z -> (-. A.x x = y -> (z = y -> A.x z = y)))
13	12	imp 350	. . . . . 6 |- ((-. A.x x = z /\ -. A.x x = y) -> (z = y -> A.x z = y))
14		dvelimfALT.1	. . . . . . 7 |- (ph -> A.xph)
15	14	a1i 8	. . . . . 6 |- ((-. A.x x = z /\ -. A.x x = y) -> (ph -> A.xph))
16	11, 13, 15	hbimd 1110	. . . . 5 |- ((-. A.x x = z /\ -. A.x x = y) -> ((z = y -> ph) -> A.x(z = y -> ph)))
17	8, 16	hbald 1113	. . . 4 |- ((-. A.x x = z /\ -. A.x x = y) -> (A.z(z = y -> ph) -> A.xA.z(z = y -> ph)))
18	17	ex 373	. . 3 |- (-. A.x x = z -> (-. A.x x = y -> (A.z(z = y -> ph) -> A.xA.z(z = y -> ph))))
19	5, 18	pm2.61i 126	. 2 |- (-. A.x x = y -> (A.z(z = y -> ph) -> A.xA.z(z = y -> ph)))
20		dvelimfALT.2	. . 3 |- (ps -> A.zps)
21		dvelimfALT.3	. . 3 |- (z = y -> (ph <-> ps))
22	20, 21	equsal 1151	. 2 |- (A.z(z = y -> ph) <-> ps)
23	22	albii 999	. 2 |- (A.xA.z(z = y -> ph) <-> A.xps)
24	19, 22, 23	3imtr3g 552	1 |- (-. A.x x = y -> (ps -> A.xps))

Syntax hints:  -. wn 2   -> wi 3   <-> wb 146   /\ wa 223  A.wal 954   = wceq 956

This theorem is referenced by:  dveeq2 1212  dveeq2ALT 1213  dveeq1 1354  dveeq1ALT 1355  dveel1 1356  dveel2 1357  ax15 1359  dveel2ALT 1362  ax11el 1364

This theorem was proved from axioms:  ax-1 4  ax-2 5  ax-3 6  ax-mp 7  ax-7 962  ax-gen 963  ax-10 966  ax-12 968  ax-4 973  ax-5o 975  ax-6o 978  ax-9o 1123  ax-10o 1140

This theorem depends on definitions:  df-bi 147  df-an 225

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