Theorem cfub 4920

Description: An upper bound on cofinality.

Assertion

Ref	Expression
cfub	|- (cf` A) (_ |^|{x | E.y(x = (card` y) /\ (y (_ A /\ A (_ U.y))}

Distinct variable group:   x,y,A

Proof of Theorem cfub

Step	Hyp	Ref	Expression
1		cfval 4918	. . 3 |- (A e. On -> (cf` A) = |^|{x | E.y(x = (card` y) /\ (y (_ A /\ A.z e. A E.w e. y z (_ w))})
2		ssel 2066	. . . . . . . . . . . . . . . . . 18 |- (y (_ A -> (w e. y -> w e. A))
3		onelon 2978	. . . . . . . . . . . . . . . . . . 19 |- ((A e. On /\ w e. A) -> w e. On)
4	3	ex 373	. . . . . . . . . . . . . . . . . 18 |- (A e. On -> (w e. A -> w e. On))
5	2, 4	sylan9r 471	. . . . . . . . . . . . . . . . 17 |- ((A e. On /\ y (_ A) -> (w e. y -> w e. On))
6		onelsst 3006	. . . . . . . . . . . . . . . . 17 |- (w e. On -> (z e. w -> z (_ w))
7	5, 6	syl6 22	. . . . . . . . . . . . . . . 16 |- ((A e. On /\ y (_ A) -> (w e. y -> (z e. w -> z (_ w)))
8	7	imdistand 447	. . . . . . . . . . . . . . 15 |- ((A e. On /\ y (_ A) -> ((w e. y /\ z e. w) -> (w e. y /\ z (_ w)))
9	8	ancomsd 439	. . . . . . . . . . . . . 14 |- ((A e. On /\ y (_ A) -> ((z e. w /\ w e. y) -> (w e. y /\ z (_ w)))
10	9	19.22dv 1292	. . . . . . . . . . . . 13 |- ((A e. On /\ y (_ A) -> (E.w(z e. w /\ w e. y) -> E.w(w e. y /\ z (_ w)))
11		eluni 2510	. . . . . . . . . . . . 13 |- (z e. U.y <-> E.w(z e. w /\ w e. y))
12		df-rex 1653	. . . . . . . . . . . . 13 |- (E.w e. y z (_ w <-> E.w(w e. y /\ z (_ w))
13	10, 11, 12	3imtr4g 555	. . . . . . . . . . . 12 |- ((A e. On /\ y (_ A) -> (z e. U.y -> E.w e. y z (_ w))
14	13	r19.20sdv 1713	. . . . . . . . . . 11 |- ((A e. On /\ y (_ A) -> (A.z e. A z e. U.y -> A.z e. A E.w e. y z (_ w))
15		dfss3 2062	. . . . . . . . . . 11 |- (A (_ U.y <-> A.z e. A z e. U.y)
16	14, 15	syl5ib 206	. . . . . . . . . 10 |- ((A e. On /\ y (_ A) -> (A (_ U.y -> A.z e. A E.w e. y z (_ w))
17	16	ex 373	. . . . . . . . 9 |- (A e. On -> (y (_ A -> (A (_ U.y -> A.z e. A E.w e. y z (_ w)))
18	17	imdistand 447	. . . . . . . 8 |- (A e. On -> ((y (_ A /\ A (_ U.y) -> (y (_ A /\ A.z e. A E.w e. y z (_ w)))
19	18	anim2d 563	. . . . . . 7 |- (A e. On -> ((x = (card` y) /\ (y (_ A /\ A (_ U.y)) -> (x = (card` y) /\ (y (_ A /\ A.z e. A E.w e. y z (_ w))))
20	19	19.22dv 1292	. . . . . 6 |- (A e. On -> (E.y(x = (card` y) /\ (y (_ A /\ A (_ U.y)) -> E.y(x = (card` y) /\ (y (_ A /\ A.z e. A E.w e. y z (_ w))))
21	20	19.21aiv 1288	. . . . 5 |- (A e. On -> A.x(E.y(x = (card` y) /\ (y (_ A /\ A (_ U.y)) -> E.y(x = (card` y) /\ (y (_ A /\ A.z e. A E.w e. y z (_ w))))
22		ss2ab 2119	. . . . 5 |- ({x | E.y(x = (card` y) /\ (y (_ A /\ A (_ U.y))} (_ {x | E.y(x = (card` y) /\ (y (_ A /\ A.z e. A E.w e. y z (_ w))} <-> A.x(E.y(x = (card` y) /\ (y (_ A /\ A (_ U.y)) -> E.y(x = (card` y) /\ (y (_ A /\ A.z e. A E.w e. y z (_ w))))
23	21, 22	sylibr 200	. . . 4 |- (A e. On -> {x | E.y(x = (card` y) /\ (y (_ A /\ A (_ U.y))} (_ {x | E.y(x = (card` y) /\ (y (_ A /\ A.z e. A E.w e. y z (_ w))})
24		intss 2558	. . . 4 |- ({x | E.y(x = (card` y) /\ (y (_ A /\ A (_ U.y))} (_ {x | E.y(x = (card` y) /\ (y (_ A /\ A.z e. A E.w e. y z (_ w))} -> |^|{x | E.y(x = (card` y) /\ (y (_ A /\ A.z e. A E.w e. y z (_ w))} (_ |^|{x | E.y(x = (card` y) /\ (y (_ A /\ A (_ U.y))})
25	23, 24	syl 10	. . 3 |- (A e. On -> |^|{x | E.y(x = (card` y) /\ (y (_ A /\ A.z e. A E.w e. y z (_ w))} (_ |^|{x | E.y(x = (card` y) /\ (y (_ A /\ A (_ U.y))})
26	1, 25	eqsstrd 2098	. 2 |- (A e. On -> (cf` A) (_ |^|{x | E.y(x = (card` y) /\ (y (_ A /\ A (_ U.y))})
27		0ss 2305	. . 3 |- (/) (_ |^|{x | E.y(x = (card` y) /\ (y (_ A /\ A (_ U.y))}
28		cffnon 4919	. . . . . . . 8 |- cf Fn On
29		fndm 3593	. . . . . . . 8 |- (cf Fn On -> dom cf = On)
30	28, 29	ax-mp 7	. . . . . . 7 |- dom cf = On
31	30	eleq2i 1541	. . . . . 6 |- (A e. dom cf <-> A e. On)
32	31	negbii 187	. . . . 5 |- (-. A e. dom cf <-> -. A e. On)
33		ndmfv 3751	. . . . 5 |- (-. A e. dom cf -> (cf` A) = (/))
34	32, 33	sylbir 201	. . . 4 |- (-. A e. On -> (cf` A) = (/))
35	34	sseq1d 2091	. . 3 |- (-. A e. On -> ((cf` A) (_ |^|{x | E.y(x = (card` y) /\ (y (_ A /\ A (_ U.y))} <-> (/) (_ |^|{x | E.y(x = (card` y) /\ (y (_ A /\ A (_ U.y))}))
36	27, 35	mpbiri 194	. 2 |- (-. A e. On -> (cf` A) (_ |^|{x | E.y(x = (card` y) /\ (y (_ A /\ A (_ U.y))})
37	26, 36	pm2.61i 126	1 |- (cf` A) (_ |^|{x | E.y(x = (card` y) /\ (y (_ A /\ A (_ U.y))}

Syntax hints:  -. wn 2   -> wi 3   /\ wa 223  A.wal 956   = wceq 958   e. wcel 960  E.wex 982  {cab 1466  A.wral 1648  E.wrex 1649   (_ wss 2050  (/)c0 2283  U.cuni 2507  |^|cint 2537  Oncon0 2954  dom cdm 3176   Fn wfn 3183  ` cfv 3188  cardccrd 4823  cfccf 4825

This theorem is referenced by:  cflim 4921  cf0 4922

This theorem was proved from axioms:  ax-1 4  ax-2 5  ax-3 6  ax-mp 7  ax-7 964  ax-gen 965  ax-8 966  ax-9 967  ax-10 968  ax-11 969  ax-12 970  ax-13 971  ax-14 972  ax-17 973  ax-4 975  ax-5o 977  ax-6o 980  ax-9o 1125  ax-10o 1142  ax-16 1212  ax-11o 1220  ax-ext 1462  ax-sep 2708  ax-pow 2748  ax-pr 2785  ax-un 2872

This theorem depends on definitions:  df-bi 147  df-or 224  df-an 225  df-3an 779  df-ex 983  df-sb 1174  df-eu 1384  df-mo 1385  df-clab 1467  df-cleq 1472  df-clel 1475  df-ne 1590  df-ral 1652  df-rex 1653  df-v 1815  df-dif 2052  df-un 2053  df-in 2054  df-ss 2056  df-nul 2284  df-pw 2406  df-sn 2416  df-pr 2417  df-op 2420  df-uni 2508  df-int 2538  df-br 2625  df-opab 2672  df-tr 2686  df-eprel 2838  df-id 2841  df-po 2846  df-so 2856  df-fr 2923  df-we 2940  df-ord 2957  df-on 2958  df-xp 3190  df-rel 3191  df-cnv 3192  df-co 3193  df-dm 3194  df-rn 3195  df-res 3196  df-ima 3197  df-fun 3198  df-fn 3199  df-fv 3204  df-cf 4828

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