Theorem rgen2a 2604

Description: Generalization rule for restricted quantification. Note that x and y are not required to be disjoint. This proof illustrates the use of dvelim 2077. Usage of rgen2 2636 instead is highly encouraged. (Contributed by NM, 23-Nov-1994.) (Proof rewritten by Jim Kingdon, 1-Jun-2018.) (New usage is discouraged.)

Hypothesis

Ref	Expression
rgen2a.1	|- ( ( x e. A /\ y e. A ) -> ph )

Assertion

Ref	Expression
rgen2a	|- A. x e. A A. y e. A ph

Distinct variable group:   y, A

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

Proof of Theorem rgen2a

Dummy variable z is distinct from all other variables.

Step	Hyp	Ref	Expression
1		nfv 1581	. . . . 5 |- F/ y z e. A
2		eleq1 2301	. . . . 5 |- ( z = x -> ( z e. A <-> x e. A ) )
3	1, 2	dvelimor 2078	. . . 4 |- ( A. y y = x \/ F/ y x e. A )
4		eleq1 2301	. . . . . . . . 9 |- ( y = x -> ( y e. A <-> x e. A ) )
5		rgen2a.1	. . . . . . . . . 10 |- ( ( x e. A /\ y e. A ) -> ph )
6	5	ex 115	. . . . . . . . 9 |- ( x e. A -> ( y e. A -> ph ) )
7	4, 6	biimtrdi 163	. . . . . . . 8 |- ( y = x -> ( y e. A -> ( y e. A -> ph ) ) )
8	7	pm2.43d 50	. . . . . . 7 |- ( y = x -> ( y e. A -> ph ) )
9	8	alimi 1508	. . . . . 6 |- ( A. y y = x -> A. y ( y e. A -> ph ) )
10	9	a1d 22	. . . . 5 |- ( A. y y = x -> ( x e. A -> A. y ( y e. A -> ph ) ) )
11		nfr 1571	. . . . . 6 |- ( F/ y x e. A -> ( x e. A -> A. y x e. A ) )
12	6	alimi 1508	. . . . . 6 |- ( A. y x e. A -> A. y ( y e. A -> ph ) )
13	11, 12	syl6 33	. . . . 5 |- ( F/ y x e. A -> ( x e. A -> A. y ( y e. A -> ph ) ) )
14	10, 13	jaoi 728	. . . 4 |- ( ( A. y y = x \/ F/ y x e. A ) -> ( x e. A -> A. y ( y e. A -> ph ) ) )
15	3, 14	ax-mp 5	. . 3 |- ( x e. A -> A. y ( y e. A -> ph ) )
16		df-ral 2533	. . 3 |- ( A. y e. A ph <-> A. y ( y e. A -> ph ) )
17	15, 16	sylibr 134	. 2 |- ( x e. A -> A. y e. A ph )
18	17	rgen 2603	1 |- A. x e. A A. y e. A ph

This proof depends on syntax axioms:   -> wi 4   /\ wa 104   \/ wo 720   A.wal 1400   = wceq 1402   F/wnf 1513   e. wcel 2209   A.wral 2528

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 721  ax-5 1500  ax-7 1501  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-8 1557  ax-10 1558  ax-11 1559  ax-i12 1560  ax-bndl 1562  ax-4 1563  ax-17 1579  ax-i9 1583  ax-ial 1587  ax-i5r 1588  ax-ext 2220

This proof depends on definitions:  df-bi 117  df-nf 1514  df-sb 1816  df-cleq 2231  df-clel 2234  df-ral 2533

This theorem is used by:  ordsucunielexmid  4680  onintexmid  4722  isoid  6019  issmo  6564  oawordriexmid  6748  ecopover  6912  ecopoverg  6915  1domsn  7121  unfiexmid  7231  axaddf  8241  axmulf  8242  subf  8535  negiso  9293  cnref1o  10067  xaddf  10262  ioof  10389  fzof  10567  xrnegiso  12052  reeff1  12491  gcdf  12773  eucalgf  12857  qredeu  12899  qnnen  13379  strsetsid  13442  hmeofn  15545  ismeti  15589  qtopbasss  15764  tgqioo  15798  peano4nninf  17272