Theorem r19.12 1281

Description: Theorem 19.12 of [Margaris] p. 89 with restricted quantifiers.

Assertion

Ref	Expression
r19.12	|- (E.x e. A A.y e. B ph -> A.y e. B E.x e. A ph)

Distinct variable group(s):   x,y   y,A   x,B

Proof of Theorem r19.12

Step	Hyp	Ref	Expression
1		ax-17 925	. . . 4 |- (x e. A -> A.y x e. A)
2		hbra1 1237	. . . 4 |- (A.y e. B ph -> A.yA.y e. B ph)
3	1, 2	hbrex 1238	. . 3 |- (E.x e. A A.y e. B ph -> A.yE.x e. A A.y e. B ph)
4		ax-1 3	. . 3 |- (E.x e. A A.y e. B ph -> (y e. B -> E.x e. A A.y e. B ph))
5	3, 4	r19.21ai 1258	. 2 |- (E.x e. A A.y e. B ph -> A.y e. B E.x e. A A.y e. B ph)
6		ra4 1243	. . . . . 6 |- (A.y e. B ph -> (y e. B -> ph))
7	6	com12 13	. . . . 5 |- (y e. B -> (A.y e. B ph -> ph))
8	7	a1d 14	. . . 4 |- (y e. B -> (x e. A -> (A.y e. B ph -> ph)))
9	8	r19.22dv 1278	. . 3 |- (y e. B -> (E.x e. A A.y e. B ph -> E.x e. A ph))
10	9	r19.20i 1253	. 2 |- (A.y e. B E.x e. A A.y e. B ph -> A.y e. B E.x e. A ph)
11	5, 10	syl 12	1 |- (E.x e. A A.y e. B ph -> A.y e. B E.x e. A ph)

Syntax hints:   -> wi 2   e. wcel 1092  A.wral 1201  E.wrex 1202

This theorem is referenced by:  iuniin 2001

This theorem was proved from axioms:  ax-1 3  ax-2 4  ax-3 5  ax-mp 6  ax-4 673  ax-5 674  ax-6 675  ax-7 676  ax-gen 677  ax-17 925

This theorem depends on definitions:  df-bi 128  df-an 198  df-ex 679  df-ral 1205  df-rex 1206

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