Theorem a16g 1271

Description: A generalization of axiom ax-16 1206.

Assertion

Ref	Expression
a16g	|- (A.x x = y -> (ph -> A.zph))

Distinct variable group:   x,y

Proof of Theorem a16g

Step	Hyp	Ref	Expression
1		hbae 1141	. . 3 |- (A.x x = y -> A.zA.x x = y)
2		ax-9 962	. . . . 5 |- -. A.x -. x = z
3		ax-16 1206	. . . . 5 |- (A.x x = y -> (-. x = z -> A.x -. x = z))
4	2, 3	mt3i 113	. . . 4 |- (A.x x = y -> x = z)
5		equcomi 1124	. . . 4 |- (x = z -> z = x)
6	4, 5	syl 10	. . 3 |- (A.x x = y -> z = x)
7	1, 6	19.21ai 995	. 2 |- (A.x x = y -> A.z z = x)
8		ax-16 1206	. . 3 |- (A.x x = y -> (ph -> A.xph))
9		pm4.2i 171	. . . . 5 |- (A.z z = x -> (ph <-> ph))
10	9	dral1 1150	. . . 4 |- (A.z z = x -> (A.zph <-> A.xph))
11	10	biimprd 154	. . 3 |- (A.z z = x -> (A.xph -> A.zph))
12	8, 11	syl9r 58	. 2 |- (A.z z = x -> (A.x x = y -> (ph -> A.zph)))
13	7, 12	mpcom 49	1 |- (A.x x = y -> (ph -> A.zph))

Syntax hints:  -. wn 2   -> wi 3  A.wal 951   = wceq 953

This theorem is referenced by:  a16gb 1272  ax11inda2 1363

This theorem was proved from axioms:  ax-1 4  ax-2 5  ax-3 6  ax-mp 7  ax-7 959  ax-gen 960  ax-8 961  ax-9 962  ax-10 963  ax-12 965  ax-4 970  ax-5o 972  ax-6o 975  ax-9o 1119  ax-10o 1136  ax-16 1206

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

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