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Theorem hlimcaui 5141
Description: If a sequence in Hilbert space subset converges to a limit, it is a Cauchy sequence.
Hypotheses
Ref Expression
hlimcau.1 AV
hlimcau.2 FV
hlimcaui.4 Fv A
Assertion
Ref Expression
hlimcaui F ∈ Cauchy

Proof of Theorem hlimcaui
StepHypRef Expression
1 hlimcaui.4 . . . 4 Fv A
2 hlimcau.2 . . . . 5 FV
3 hlimcau.1 . . . . 5 AV
42, 3hlimseq 5109 . . . 4 (Fv AF:ℕ–→ ℋ )
51, 4ax-mp 6 . . 3 F:ℕ–→ ℋ
6 breq2 2066 . . . . . . . . 9 (v = (x / 2) → (0 < v ↔ 0 < (x / 2)))
7 breq2 2066 . . . . . . . . . . . 12 (v = (x / 2) → ((norm ‘((Fz) −v A)) < v ↔ (norm ‘((Fz) −v A)) < (x / 2)))
87imbi2d 464 . . . . . . . . . . 11 (v = (x / 2) → ((yz → (norm ‘((Fz) −v A)) < v) ↔ (yz → (norm ‘((Fz) −v A)) < (x / 2))))
98biraldv 1219 . . . . . . . . . 10 (v = (x / 2) → (∀z ∈ ℕ (yz → (norm ‘((Fz) −v A)) < v) ↔ ∀z ∈ ℕ (yz → (norm ‘((Fz) −v A)) < (x / 2))))
109birexdv 1220 . . . . . . . . 9 (v = (x / 2) → (∃y ∈ ℕ ∀z ∈ ℕ (yz → (norm ‘((Fz) −v A)) < v) ↔ ∃y ∈ ℕ ∀z ∈ ℕ (yz → (norm ‘((Fz) −v A)) < (x / 2))))
116, 10imbi12d 474 . . . . . . . 8 (v = (x / 2) → ((0 < v → ∃y ∈ ℕ ∀z ∈ ℕ (yz → (norm ‘((Fz) −v A)) < v)) ↔ (0 < (x / 2) → ∃y ∈ ℕ ∀z ∈ ℕ (yz → (norm ‘((Fz) −v A)) < (x / 2)))))
122, 3hlimvec 5110 . . . . . . . . . 10 (Fv AA ∈ ℋ )
131, 12ax-mp 6 . . . . . . . . 9 A ∈ ℋ
14 hlim2 5112 . . . . . . . . . 10 ((F:ℕ–→ ℋ ∧ A ∈ ℋ ) → (Fv A ↔ ∀v ∈ ℝ (0 < v → ∃y ∈ ℕ ∀z ∈ ℕ (yz → (norm ‘((Fz) −v A)) < v))))
151, 14mpbii 168 . . . . . . . . 9 ((F:ℕ–→ ℋ ∧ A ∈ ℋ ) → ∀v ∈ ℝ (0 < v → ∃y ∈ ℕ ∀z ∈ ℕ (yz → (norm ‘((Fz) −v A)) < v)))
165, 13, 15mp2an 520 . . . . . . . 8 v ∈ ℝ (0 < v → ∃y ∈ ℕ ∀z ∈ ℕ (yz → (norm ‘((Fz) −v A)) < v))
1711, 16vtoclri 1393 . . . . . . 7 ((x / 2) ∈ ℝ → (0 < (x / 2) → ∃y ∈ ℕ ∀z ∈ ℕ (yz → (norm ‘((Fz) −v A)) < (x / 2))))
18 opreq1 3006 . . . . . . . . . 10 (x = if(x ∈ ℝ, x, 0) → (x / 2) = (if(x ∈ ℝ, x, 0) / 2))
1918eleq1d 1155 . . . . . . . . 9 (x = if(x ∈ ℝ, x, 0) → ((x / 2) ∈ ℝ ↔ (if(x ∈ ℝ, x, 0) / 2) ∈ ℝ))
20 ax0re 4063 . . . . . . . . . . 11 0 ∈ ℝ
2120elimel 1793 . . . . . . . . . 10 if(x ∈ ℝ, x, 0) ∈ ℝ
22 2re 4470 . . . . . . . . . 10 2 ∈ ℝ
23 2pos 4479 . . . . . . . . . . 11 0 < 2
2422, 23gt0ne0i 4345 . . . . . . . . . 10 2 ≠ 0
2521, 22, 24redivcl 4274 . . . . . . . . 9 (if(x ∈ ℝ, x, 0) / 2) ∈ ℝ
2619, 25dedth 1784 . . . . . . . 8 (x ∈ ℝ → (x / 2) ∈ ℝ)
2726adantr 306 . . . . . . 7 ((x ∈ ℝ ∧ 0 < x) → (x / 2) ∈ ℝ)
28 breq2 2066 . . . . . . . . . 10 (x = if(x ∈ ℝ, x, 0) → (0 < x ↔ 0 < if(x ∈ ℝ, x, 0)))
2918breq2d 2072 . . . . . . . . . 10 (x = if(x ∈ ℝ, x, 0) → (0 < (x / 2) ↔ 0 < (if(x ∈ ℝ, x, 0) / 2)))
3028, 29imbi12d 474 . . . . . . . . 9 (x = if(x ∈ ℝ, x, 0) → ((0 < x → 0 < (x / 2)) ↔ (0 < if(x ∈ ℝ, x, 0) → 0 < (if(x ∈ ℝ, x, 0) / 2))))
3121, 22, 23divgt0lem 4389 . . . . . . . . 9 (0 < if(x ∈ ℝ, x, 0) → 0 < (if(x ∈ ℝ, x, 0) / 2))
3230, 31dedth 1784 . . . . . . . 8 (x ∈ ℝ → (0 < x → 0 < (x / 2)))
3332imp 277 . . . . . . 7 ((x ∈ ℝ ∧ 0 < x) → 0 < (x / 2))
3417, 27, 33sylc 62 . . . . . 6 ((x ∈ ℝ ∧ 0 < x) → ∃y ∈ ℕ ∀z ∈ ℕ (yz → (norm ‘((Fz) −v A)) < (x / 2)))
35 prth 429 . . . . . . . . . . . 12 (((yz → (norm ‘((Fz) −v A)) < (x / 2)) ∧ (yw → (norm ‘((Fw) −v A)) < (x / 2))) → ((yzyw) → ((norm ‘((Fz) −v A)) < (x / 2) ∧ (norm ‘((Fw) −v A)) < (x / 2))))
36 normsubt 5091 . . . . . . . . . . . . . . . . 17 ((A ∈ ℋ ∧ (Fw) ∈ ℋ ) → (norm ‘(Av (Fw))) = (norm ‘((Fw) −v A)))
3736breq1d 2071 . . . . . . . . . . . . . . . 16 ((A ∈ ℋ ∧ (Fw) ∈ ℋ ) → ((norm ‘(Av (Fw))) < (x / 2) ↔ (norm ‘((Fw) −v A)) < (x / 2)))
3837anbi2d 468 . . . . . . . . . . . . . . 15 ((A ∈ ℋ ∧ (Fw) ∈ ℋ ) → (((norm ‘((Fz) −v A)) < (x / 2) ∧ (norm ‘(Av (Fw))) < (x / 2)) ↔ ((norm ‘((Fz) −v A)) < (x / 2) ∧ (norm ‘((Fw) −v A)) < (x / 2))))
3938adantl 305 . . . . . . . . . . . . . 14 (((x ∈ ℝ ∧ z ∈ ℕ) ∧ (A ∈ ℋ ∧ (Fw) ∈ ℋ )) → (((norm ‘((Fz) −v A)) < (x / 2) ∧ (norm ‘(Av (Fw))) < (x / 2)) ↔ ((norm ‘((Fz) −v A)) < (x / 2) ∧ (norm ‘((Fw) −v A)) < (x / 2))))
40 ffvrn 2890 . . . . . . . . . . . . . . . . . . . . . 22 ((F:ℕ–→ ℋ ∧ z ∈ ℕ) → (Fz) ∈ ℋ )
415, 40mpan 518 . . . . . . . . . . . . . . . . . . . . 21 (z ∈ ℕ → (Fz) ∈ ℋ )
4241anim1i 269 . . . . . . . . . . . . . . . . . . . 20 ((z ∈ ℕ ∧ (Fw) ∈ ℋ ) → ((Fz) ∈ ℋ ∧ (Fw) ∈ ℋ ))
4342ancoms 334 . . . . . . . . . . . . . . . . . . 19 (((Fw) ∈ ℋ ∧ z ∈ ℕ) → ((Fz) ∈ ℋ ∧ (Fw) ∈ ℋ ))
4443anim1i 269 . . . . . . . . . . . . . . . . . 18 ((((Fw) ∈ ℋ ∧ z ∈ ℕ) ∧ (A ∈ ℋ ∧ x ∈ ℝ)) → (((Fz) ∈ ℋ ∧ (Fw) ∈ ℋ ) ∧ (A ∈ ℋ ∧ x ∈ ℝ)))
4544ancoms 334 . . . . . . . . . . . . . . . . 17 (((A ∈ ℋ ∧ x ∈ ℝ) ∧ ((Fw) ∈ ℋ ∧ z ∈ ℕ)) → (((Fz) ∈ ℋ ∧ (Fw) ∈ ℋ ) ∧ (A ∈ ℋ ∧ x ∈ ℝ)))
4645an4s 390 . . . . . . . . . . . . . . . 16 (((A ∈ ℋ ∧ (Fw) ∈ ℋ ) ∧ (x ∈ ℝ ∧ z ∈ ℕ)) → (((Fz) ∈ ℋ ∧ (Fw) ∈ ℋ ) ∧ (A ∈ ℋ ∧ x ∈ ℝ)))
4746ancoms 334 . . . . . . . . . . . . . . 15 (((x ∈ ℝ ∧ z ∈ ℕ) ∧ (A ∈ ℋ ∧ (Fw) ∈ ℋ )) → (((Fz) ∈ ℋ ∧ (Fw) ∈ ℋ ) ∧ (A ∈ ℋ ∧ x ∈ ℝ)))
48 norm3lemt 5097 . . . . . . . . . . . . . . 15 ((((Fz) ∈ ℋ ∧ (Fw) ∈ ℋ ) ∧ (A ∈ ℋ ∧ x ∈ ℝ)) → (((norm ‘((Fz) −v A)) < (x / 2) ∧ (norm ‘(Av (Fw))) < (x / 2)) → (norm ‘((Fz) −v (Fw))) < x))
4947, 48syl 12 . . . . . . . . . . . . . 14 (((x ∈ ℝ ∧ z ∈ ℕ) ∧ (A ∈ ℋ ∧ (Fw) ∈ ℋ )) → (((norm ‘((Fz) −v A)) < (x / 2) ∧ (norm ‘(Av (Fw))) < (x / 2)) → (norm ‘((Fz) −v (Fw))) < x))
5039, 49sylbird 180 . . . . . . . . . . . . 13 (((x ∈ ℝ ∧ z ∈ ℕ) ∧ (A ∈ ℋ ∧ (Fw) ∈ ℋ )) → (((norm ‘((Fz) −v A)) < (x / 2) ∧ (norm ‘((Fw) −v A)) < (x / 2)) → (norm ‘((Fz) −v (Fw))) < x))
51 ffvrn 2890 . . . . . . . . . . . . . . 15 ((F:ℕ–→ ℋ ∧ w ∈ ℕ) → (Fw) ∈ ℋ )
525, 51mpan 518 . . . . . . . . . . . . . 14 (w ∈ ℕ → (Fw) ∈ ℋ )
5352, 13jctil 240 . . . . . . . . . . . . 13 (w ∈ ℕ → (A ∈ ℋ ∧ (Fw) ∈ ℋ ))
5450, 53sylan2 346 . . . . . . . . . . . 12 (((x ∈ ℝ ∧ z ∈ ℕ) ∧ w ∈ ℕ) → (((norm ‘((Fz) −v A)) < (x / 2) ∧ (norm ‘((Fw) −v A)) < (x / 2)) → (norm ‘((Fz) −v (Fw))) < x))
5535, 54syl9r 56 . . . . . . . . . . 11 (((x ∈ ℝ ∧ z ∈ ℕ) ∧ w ∈ ℕ) → (((yz → (norm ‘((Fz) −v A)) < (x / 2)) ∧ (yw → (norm ‘((Fw) −v A)) < (x / 2))) → ((yzyw) → (norm ‘((Fz) −v (Fw))) < x)))
5655r19.20dva 1256 . . . . . . . . . 10 ((x ∈ ℝ ∧ z ∈ ℕ) → (∀w ∈ ℕ ((yz → (norm ‘((Fz) −v A)) < (x / 2)) ∧ (yw → (norm ‘((Fw) −v A)) < (x / 2))) → ∀w ∈ ℕ ((yzyw) → (norm ‘((Fz) −v (Fw))) < x)))
5756r19.20dva 1256 . . . . . . . . 9 (x ∈ ℝ → (∀z ∈ ℕ ∀w ∈ ℕ ((yz → (norm ‘((Fz) −v A)) < (x / 2)) ∧ (yw → (norm ‘((Fw) −v A)) < (x / 2))) → ∀z ∈ ℕ ∀w ∈ ℕ ((yzyw) → (norm ‘((Fz) −v (Fw))) < x)))
58 raaan 1775 . . . . . . . . . 10 (∀z ∈ ℕ ∀w ∈ ℕ ((yz → (norm ‘((Fz) −v A)) < (x / 2)) ∧ (yw → (norm ‘((Fw) −v A)) < (x / 2))) ↔ (∀z ∈ ℕ (yz → (norm ‘((Fz) −v A)) < (x / 2)) ∧ ∀w ∈ ℕ (yw → (norm ‘((Fw) −v A)) < (x / 2))))
59 breq2 2066 . . . . . . . . . . . . 13 (w = z → (ywyz))
60 fveq2 2832 . . . . . . . . . . . . . . . 16 (w = z → (Fw) = (Fz))
6160opreq1d 3012 . . . . . . . . . . . . . . 15 (w = z → ((Fw) −v A) = ((Fz) −v A))
6261fveq2d 2836 . . . . . . . . . . . . . 14 (w = z → (norm ‘((Fw) −v A)) = (norm ‘((Fz) −v A)))
6362breq1d 2071 . . . . . . . . . . . . 13 (w = z → ((norm ‘((Fw) −v A)) < (x / 2) ↔ (norm ‘((Fz) −v A)) < (x / 2)))
6459, 63imbi12d 474 . . . . . . . . . . . 12 (w = z → ((yw → (norm ‘((Fw) −v A)) < (x / 2)) ↔ (yz → (norm ‘((Fz) −v A)) < (x / 2))))
6564cbvralv 1333 . . . . . . . . . . 11 (∀w ∈ ℕ (yw → (norm ‘((Fw) −v A)) < (x / 2)) ↔ ∀z ∈ ℕ (yz → (norm ‘((Fz) −v A)) < (x / 2)))
6665anbi2i 367 . . . . . . . . . 10 ((∀z ∈ ℕ (yz → (norm ‘((Fz) −v A)) < (x / 2)) ∧ ∀w ∈ ℕ (yw → (norm ‘((Fw) −v A)) < (x / 2))) ↔ (∀z ∈ ℕ (yz → (norm ‘((Fz) −v A)) < (x / 2)) ∧ ∀z ∈ ℕ (yz → (norm ‘((Fz) −v A)) < (x / 2))))
67 anidm 331 . . . . . . . . . 10 ((∀z ∈ ℕ (yz → (norm ‘((Fz) −v A)) < (x / 2)) ∧ ∀z ∈ ℕ (yz → (norm ‘((Fz) −v A)) < (x / 2))) ↔ ∀z ∈ ℕ (yz → (norm ‘((Fz) −v A)) < (x / 2)))
6858, 66, 673bitr 155 . . . . . . . . 9 (∀z ∈ ℕ ∀w ∈ ℕ ((yz → (norm ‘((Fz) −v A)) < (x / 2)) ∧ (yw → (norm ‘((Fw) −v A)) < (x / 2))) ↔ ∀z ∈ ℕ (yz → (norm ‘((Fz) −v A)) < (x / 2)))
6957, 68syl5ibr 182 . . . . . . . 8 (x ∈ ℝ → (∀z ∈ ℕ (yz → (norm ‘((Fz) −v A)) < (x / 2)) → ∀z ∈ ℕ ∀w ∈ ℕ ((yzyw) → (norm ‘((Fz) −v (Fw))) < x)))
7069r19.22sdv 1279 . . . . . . 7 (x ∈ ℝ → (∃y ∈ ℕ ∀z ∈ ℕ (yz → (norm ‘((Fz) −v A)) < (x / 2)) → ∃y ∈ ℕ ∀z ∈ ℕ ∀w ∈ ℕ ((yzyw) → (norm ‘((Fz) −v (Fw))) < x)))
7170adantr 306 . . . . . 6 ((x ∈ ℝ ∧ 0 < x) → (∃y ∈ ℕ ∀z ∈ ℕ (yz → (norm ‘((Fz) −v A)) < (x / 2)) → ∃y ∈ ℕ ∀z ∈ ℕ ∀w ∈ ℕ ((yzyw) → (norm ‘((Fz) −v (Fw))) < x)))
7234, 71mpd 46 . . . . 5 ((x ∈ ℝ ∧ 0 < x) → ∃y ∈ ℕ ∀z ∈ ℕ ∀w ∈ ℕ ((yzyw) → (norm ‘((Fz) −v (Fw))) < x))
7372exp 291 . . . 4 (x ∈ ℝ → (0 < x → ∃y ∈ ℕ ∀z ∈ ℕ ∀w ∈ ℕ ((yzyw) → (norm ‘((Fz) −v (Fw))) < x)))
7473rgen 1247 . . 3 x ∈ ℝ (0 < x → ∃y ∈ ℕ ∀z ∈ ℕ ∀w ∈ ℕ ((yzyw) → (norm ‘((Fz) −v (Fw))) < x))
755, 74pm3.2i 234 . 2 (F:ℕ–→ ℋ ∧ ∀x ∈ ℝ (0 < x → ∃y ∈ ℕ ∀z ∈ ℕ ∀w ∈ ℕ ((yzyw) → (norm ‘((Fz) −v (Fw))) < x)))
76 hcauchy 5103 . 2 (F ∈ Cauchy ↔ (F:ℕ–→ ℋ ∧ ∀x ∈ ℝ (0 < x → ∃y ∈ ℕ ∀z ∈ ℕ ∀w ∈ ℕ ((yzyw) → (norm ‘((Fz) −v (Fw))) < x))))
7775, 76mpbir 165 1 F ∈ Cauchy
Colors of variables: wff set class
Syntax hints:   → wi 2   ↔ wb 127   ∧ wa 196   = weq 797   = wceq 1091   ∈ wcel 1092  ∀wral 1201  ∃wrex 1202  Vcvv 1348  ifcif 1776   class class class wbr 2054  –→wf 2418   ‘cfv 2422  (class class class)co 3001  ℝcr 4027  0cc0 4028   < clt 4033   / cdiv 4091   ≤ cle 4092  ℕcn 4093  2c2 4454   ℋ chil 4958   −v cmv 4962  normcno 4964  Cauchyccau 4965   ⇝v chli 4966
This theorem is referenced by:  hlimcau 5142
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-8 798  ax-9 799  ax-10 800  ax-11 801  ax-12 802  ax-13 804  ax-14 805  ax-16 922  ax-17 925  ax-ext 1074  ax-rep 1075  ax-un 1076  ax-pow 1077  ax-reg 1078  ax-inf 1079  ax-hvaddcl 4984  ax-hvcom 4985  ax-hvass 4986  ax-hvzercl 4987  ax-hvaddid 4988  ax-hvmulcl 4989  ax-hvmulid 4991  ax-hvmulass 4992  ax-hvdistr1 4993  ax-hvdistr2 4994  ax-hvmulzer 4995  ax-hicl 5043  ax-his1 5045  ax-his2 5046  ax-his3 5047  ax-his4 5048
This theorem depends on definitions:  df-bi 128  df-or 197  df-an 198  df-3or 582  df-3an 583  df-ex 679  df-sb 853  df-eu 1009  df-mo 1010  df-clab 1093  df-cleq 1097  df-clel 1099  df-ne 1192  df-ral 1205  df-rex 1206  df-reu 1207  df-rab 1208  df-v 1349  df-sbc 1441  df-dif 1489  df-un 1490  df-in 1491  df-ss 1492  df-pss 1494  df-nul 1708  df-if 1777  df-pw 1799  df-sn 1811  df-pr 1812  df-tp 1814  df-op 1815  df-uni 1920  df-int 1966  df-iun 1996  df-tr 2042  df-br 2063  df-opab 2098  df-eprel 2122  df-id 2125  df-po 2128  df-so 2138  df-sup 2154  df-fr 2169  df-we 2186  df-ord 2202  df-on 2203  df-lim 2204  df-suc 2205  df-om 2373  df-xp 2424  df-rel 2425  df-cnv 2426  df-co 2427  df-dm 2428  df-rn 2429  df-res 2430  df-ima 2431  df-fun 2432  df-fn 2433  df-f 2434  df-f1 2435  df-fo 2436  df-f1o 2437  df-fv 2438  df-rdg 2970  df-opr 3003  df-oprab 3004  df-1st 3087  df-2nd 3088  df-1o 3104  df-oadd 3106  df-omul 3107  df-er 3200  df-ec 3202  df-qs 3205  df-ni 3794  df-pli 3795  df-mi 3796  df-lti 3797  df-plpq 3829  df-mpq 3830  df-enq 3831  df-nq 3832  df-plq 3833  df-mq 3834  df-rq 3835  df-ltq 3836  df-1q 3837  df-np 3880  df-1p 3881  df-plp 3882  df-mp 3883  df-ltp 3884  df-plpr 3958  df-mpr 3959  df-enr 3960  df-nr 3961  df-plr 3962  df-mr 3963  df-ltr 3964  df-0r 3965  df-1r 3966  df-m1r 3967  df-c 4034  df-0 4035  df-1 4036  df-i 4037  df-r 4038  df-plus 4039  df-mul 4040  df-lt 4041  df-sub 4133  df-neg 4135  df-div 4216  df-le 4277  df-n 4423  df-2 4462  df-3 4463  df-4 4464  df-n0 4535  df-z 4564  df-seq 4661  df-exp 4676  df-sqr 4728  df-re 4790  df-im 4791  df-cj 4792  df-abs 4793  df-hvsub 4996  df-hnorm 5074  df-cauchy 5102  df-hlim 5107
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