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Theorem ctbssinf 36926
Description: Using the axiom of choice, any infinite class has a countable subset. (Contributed by ML, 14-Dec-2020.)
Assertion
Ref Expression
ctbssinf 𝐴 ∈ Fin → ∃𝑥(𝑥𝐴𝑥 ≈ ω))
Distinct variable group:   𝑥,𝐴

Proof of Theorem ctbssinf
Dummy variables 𝑓 𝑛 are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 isinf 9293 . 2 𝐴 ∈ Fin → ∀𝑛 ∈ ω ∃𝑥(𝑥𝐴𝑥𝑛))
2 omex 9676 . . 3 ω ∈ V
3 sseq1 4007 . . . 4 (𝑥 = (𝑓𝑛) → (𝑥𝐴 ↔ (𝑓𝑛) ⊆ 𝐴))
4 breq1 5155 . . . 4 (𝑥 = (𝑓𝑛) → (𝑥𝑛 ↔ (𝑓𝑛) ≈ 𝑛))
53, 4anbi12d 630 . . 3 (𝑥 = (𝑓𝑛) → ((𝑥𝐴𝑥𝑛) ↔ ((𝑓𝑛) ⊆ 𝐴 ∧ (𝑓𝑛) ≈ 𝑛)))
62, 5ac6s2 10519 . 2 (∀𝑛 ∈ ω ∃𝑥(𝑥𝐴𝑥𝑛) → ∃𝑓(𝑓 Fn ω ∧ ∀𝑛 ∈ ω ((𝑓𝑛) ⊆ 𝐴 ∧ (𝑓𝑛) ≈ 𝑛)))
7 simpl 481 . . . . . 6 (((𝑓𝑛) ⊆ 𝐴 ∧ (𝑓𝑛) ≈ 𝑛) → (𝑓𝑛) ⊆ 𝐴)
87ralimi 3080 . . . . 5 (∀𝑛 ∈ ω ((𝑓𝑛) ⊆ 𝐴 ∧ (𝑓𝑛) ≈ 𝑛) → ∀𝑛 ∈ ω (𝑓𝑛) ⊆ 𝐴)
9 fvex 6915 . . . . . . . 8 (𝑓𝑛) ∈ V
109elpw 4610 . . . . . . 7 ((𝑓𝑛) ∈ 𝒫 𝐴 ↔ (𝑓𝑛) ⊆ 𝐴)
1110ralbii 3090 . . . . . 6 (∀𝑛 ∈ ω (𝑓𝑛) ∈ 𝒫 𝐴 ↔ ∀𝑛 ∈ ω (𝑓𝑛) ⊆ 𝐴)
12 fnfvrnss 7136 . . . . . . 7 ((𝑓 Fn ω ∧ ∀𝑛 ∈ ω (𝑓𝑛) ∈ 𝒫 𝐴) → ran 𝑓 ⊆ 𝒫 𝐴)
13 uniss 4920 . . . . . . . 8 (ran 𝑓 ⊆ 𝒫 𝐴 ran 𝑓 𝒫 𝐴)
14 unipw 5456 . . . . . . . 8 𝒫 𝐴 = 𝐴
1513, 14sseqtrdi 4032 . . . . . . 7 (ran 𝑓 ⊆ 𝒫 𝐴 ran 𝑓𝐴)
1612, 15syl 17 . . . . . 6 ((𝑓 Fn ω ∧ ∀𝑛 ∈ ω (𝑓𝑛) ∈ 𝒫 𝐴) → ran 𝑓𝐴)
1711, 16sylan2br 593 . . . . 5 ((𝑓 Fn ω ∧ ∀𝑛 ∈ ω (𝑓𝑛) ⊆ 𝐴) → ran 𝑓𝐴)
188, 17sylan2 591 . . . 4 ((𝑓 Fn ω ∧ ∀𝑛 ∈ ω ((𝑓𝑛) ⊆ 𝐴 ∧ (𝑓𝑛) ≈ 𝑛)) → ran 𝑓𝐴)
19 dffn5 6962 . . . . . . . . . . 11 (𝑓 Fn ω ↔ 𝑓 = (𝑛 ∈ ω ↦ (𝑓𝑛)))
2019biimpi 215 . . . . . . . . . 10 (𝑓 Fn ω → 𝑓 = (𝑛 ∈ ω ↦ (𝑓𝑛)))
2120rneqd 5944 . . . . . . . . 9 (𝑓 Fn ω → ran 𝑓 = ran (𝑛 ∈ ω ↦ (𝑓𝑛)))
2221unieqd 4925 . . . . . . . 8 (𝑓 Fn ω → ran 𝑓 = ran (𝑛 ∈ ω ↦ (𝑓𝑛)))
239dfiun3 5973 . . . . . . . 8 𝑛 ∈ ω (𝑓𝑛) = ran (𝑛 ∈ ω ↦ (𝑓𝑛))
2422, 23eqtr4di 2786 . . . . . . 7 (𝑓 Fn ω → ran 𝑓 = 𝑛 ∈ ω (𝑓𝑛))
2524adantr 479 . . . . . 6 ((𝑓 Fn ω ∧ ∀𝑛 ∈ ω ((𝑓𝑛) ⊆ 𝐴 ∧ (𝑓𝑛) ≈ 𝑛)) → ran 𝑓 = 𝑛 ∈ ω (𝑓𝑛))
26 simpr 483 . . . . . . . . 9 (((𝑓𝑛) ⊆ 𝐴 ∧ (𝑓𝑛) ≈ 𝑛) → (𝑓𝑛) ≈ 𝑛)
2726ralimi 3080 . . . . . . . 8 (∀𝑛 ∈ ω ((𝑓𝑛) ⊆ 𝐴 ∧ (𝑓𝑛) ≈ 𝑛) → ∀𝑛 ∈ ω (𝑓𝑛) ≈ 𝑛)
28 endom 9008 . . . . . . . . . 10 ((𝑓𝑛) ≈ 𝑛 → (𝑓𝑛) ≼ 𝑛)
29 nnsdom 9687 . . . . . . . . . 10 (𝑛 ∈ ω → 𝑛 ≺ ω)
30 domsdomtr 9145 . . . . . . . . . . 11 (((𝑓𝑛) ≼ 𝑛𝑛 ≺ ω) → (𝑓𝑛) ≺ ω)
31 sdomdom 9009 . . . . . . . . . . 11 ((𝑓𝑛) ≺ ω → (𝑓𝑛) ≼ ω)
3230, 31syl 17 . . . . . . . . . 10 (((𝑓𝑛) ≼ 𝑛𝑛 ≺ ω) → (𝑓𝑛) ≼ ω)
3328, 29, 32syl2anr 595 . . . . . . . . 9 ((𝑛 ∈ ω ∧ (𝑓𝑛) ≈ 𝑛) → (𝑓𝑛) ≼ ω)
3433ralimiaa 3079 . . . . . . . 8 (∀𝑛 ∈ ω (𝑓𝑛) ≈ 𝑛 → ∀𝑛 ∈ ω (𝑓𝑛) ≼ ω)
35 iunctb2 36923 . . . . . . . 8 (∀𝑛 ∈ ω (𝑓𝑛) ≼ ω → 𝑛 ∈ ω (𝑓𝑛) ≼ ω)
3627, 34, 353syl 18 . . . . . . 7 (∀𝑛 ∈ ω ((𝑓𝑛) ⊆ 𝐴 ∧ (𝑓𝑛) ≈ 𝑛) → 𝑛 ∈ ω (𝑓𝑛) ≼ ω)
3736adantl 480 . . . . . 6 ((𝑓 Fn ω ∧ ∀𝑛 ∈ ω ((𝑓𝑛) ⊆ 𝐴 ∧ (𝑓𝑛) ≈ 𝑛)) → 𝑛 ∈ ω (𝑓𝑛) ≼ ω)
3825, 37eqbrtrd 5174 . . . . 5 ((𝑓 Fn ω ∧ ∀𝑛 ∈ ω ((𝑓𝑛) ⊆ 𝐴 ∧ (𝑓𝑛) ≈ 𝑛)) → ran 𝑓 ≼ ω)
39 fvssunirn 6935 . . . . . . . . . 10 (𝑓𝑛) ⊆ ran 𝑓
4039jctl 522 . . . . . . . . 9 ((𝑓𝑛) ≈ 𝑛 → ((𝑓𝑛) ⊆ ran 𝑓 ∧ (𝑓𝑛) ≈ 𝑛))
4140adantl 480 . . . . . . . 8 (((𝑓𝑛) ⊆ 𝐴 ∧ (𝑓𝑛) ≈ 𝑛) → ((𝑓𝑛) ⊆ ran 𝑓 ∧ (𝑓𝑛) ≈ 𝑛))
4241ralimi 3080 . . . . . . 7 (∀𝑛 ∈ ω ((𝑓𝑛) ⊆ 𝐴 ∧ (𝑓𝑛) ≈ 𝑛) → ∀𝑛 ∈ ω ((𝑓𝑛) ⊆ ran 𝑓 ∧ (𝑓𝑛) ≈ 𝑛))
43 sseq1 4007 . . . . . . . . . . . 12 (𝑥 = (𝑓𝑛) → (𝑥 ran 𝑓 ↔ (𝑓𝑛) ⊆ ran 𝑓))
4443, 4anbi12d 630 . . . . . . . . . . 11 (𝑥 = (𝑓𝑛) → ((𝑥 ran 𝑓𝑥𝑛) ↔ ((𝑓𝑛) ⊆ ran 𝑓 ∧ (𝑓𝑛) ≈ 𝑛)))
459, 44spcev 3595 . . . . . . . . . 10 (((𝑓𝑛) ⊆ ran 𝑓 ∧ (𝑓𝑛) ≈ 𝑛) → ∃𝑥(𝑥 ran 𝑓𝑥𝑛))
4645ralimi 3080 . . . . . . . . 9 (∀𝑛 ∈ ω ((𝑓𝑛) ⊆ ran 𝑓 ∧ (𝑓𝑛) ≈ 𝑛) → ∀𝑛 ∈ ω ∃𝑥(𝑥 ran 𝑓𝑥𝑛))
47 isinf2 36925 . . . . . . . . 9 (∀𝑛 ∈ ω ∃𝑥(𝑥 ran 𝑓𝑥𝑛) → ¬ ran 𝑓 ∈ Fin)
4846, 47syl 17 . . . . . . . 8 (∀𝑛 ∈ ω ((𝑓𝑛) ⊆ ran 𝑓 ∧ (𝑓𝑛) ≈ 𝑛) → ¬ ran 𝑓 ∈ Fin)
49 vex 3477 . . . . . . . . . . 11 𝑓 ∈ V
5049rnex 7926 . . . . . . . . . 10 ran 𝑓 ∈ V
5150uniex 7754 . . . . . . . . 9 ran 𝑓 ∈ V
52 infinf 10599 . . . . . . . . 9 ( ran 𝑓 ∈ V → (¬ ran 𝑓 ∈ Fin ↔ ω ≼ ran 𝑓))
5351, 52ax-mp 5 . . . . . . . 8 ran 𝑓 ∈ Fin ↔ ω ≼ ran 𝑓)
5448, 53sylib 217 . . . . . . 7 (∀𝑛 ∈ ω ((𝑓𝑛) ⊆ ran 𝑓 ∧ (𝑓𝑛) ≈ 𝑛) → ω ≼ ran 𝑓)
5542, 54syl 17 . . . . . 6 (∀𝑛 ∈ ω ((𝑓𝑛) ⊆ 𝐴 ∧ (𝑓𝑛) ≈ 𝑛) → ω ≼ ran 𝑓)
5655adantl 480 . . . . 5 ((𝑓 Fn ω ∧ ∀𝑛 ∈ ω ((𝑓𝑛) ⊆ 𝐴 ∧ (𝑓𝑛) ≈ 𝑛)) → ω ≼ ran 𝑓)
57 sbth 9126 . . . . 5 (( ran 𝑓 ≼ ω ∧ ω ≼ ran 𝑓) → ran 𝑓 ≈ ω)
5838, 56, 57syl2anc 582 . . . 4 ((𝑓 Fn ω ∧ ∀𝑛 ∈ ω ((𝑓𝑛) ⊆ 𝐴 ∧ (𝑓𝑛) ≈ 𝑛)) → ran 𝑓 ≈ ω)
59 sseq1 4007 . . . . . 6 (𝑥 = ran 𝑓 → (𝑥𝐴 ran 𝑓𝐴))
60 breq1 5155 . . . . . 6 (𝑥 = ran 𝑓 → (𝑥 ≈ ω ↔ ran 𝑓 ≈ ω))
6159, 60anbi12d 630 . . . . 5 (𝑥 = ran 𝑓 → ((𝑥𝐴𝑥 ≈ ω) ↔ ( ran 𝑓𝐴 ran 𝑓 ≈ ω)))
6251, 61spcev 3595 . . . 4 (( ran 𝑓𝐴 ran 𝑓 ≈ ω) → ∃𝑥(𝑥𝐴𝑥 ≈ ω))
6318, 58, 62syl2anc 582 . . 3 ((𝑓 Fn ω ∧ ∀𝑛 ∈ ω ((𝑓𝑛) ⊆ 𝐴 ∧ (𝑓𝑛) ≈ 𝑛)) → ∃𝑥(𝑥𝐴𝑥 ≈ ω))
6463exlimiv 1925 . 2 (∃𝑓(𝑓 Fn ω ∧ ∀𝑛 ∈ ω ((𝑓𝑛) ⊆ 𝐴 ∧ (𝑓𝑛) ≈ 𝑛)) → ∃𝑥(𝑥𝐴𝑥 ≈ ω))
651, 6, 643syl 18 1 𝐴 ∈ Fin → ∃𝑥(𝑥𝐴𝑥 ≈ ω))
Colors of variables: wff setvar class
Syntax hints:  ¬ wn 3  wi 4  wb 205  wa 394   = wceq 1533  wex 1773  wcel 2098  wral 3058  Vcvv 3473  wss 3949  𝒫 cpw 4606   cuni 4912   ciun 5000   class class class wbr 5152  cmpt 5235  ran crn 5683   Fn wfn 6548  cfv 6553  ωcom 7878  cen 8969  cdom 8970  csdm 8971  Fincfn 8972
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1789  ax-4 1803  ax-5 1905  ax-6 1963  ax-7 2003  ax-8 2100  ax-9 2108  ax-10 2129  ax-11 2146  ax-12 2166  ax-ext 2699  ax-rep 5289  ax-sep 5303  ax-nul 5310  ax-pow 5369  ax-pr 5433  ax-un 7748  ax-reg 9625  ax-inf2 9674  ax-cc 10468  ax-ac2 10496
This theorem depends on definitions:  df-bi 206  df-an 395  df-or 846  df-3or 1085  df-3an 1086  df-tru 1536  df-fal 1546  df-ex 1774  df-nf 1778  df-sb 2060  df-mo 2529  df-eu 2558  df-clab 2706  df-cleq 2720  df-clel 2806  df-nfc 2881  df-ne 2938  df-ral 3059  df-rex 3068  df-rmo 3374  df-reu 3375  df-rab 3431  df-v 3475  df-sbc 3779  df-csb 3895  df-dif 3952  df-un 3954  df-in 3956  df-ss 3966  df-pss 3968  df-nul 4327  df-if 4533  df-pw 4608  df-sn 4633  df-pr 4635  df-op 4639  df-uni 4913  df-int 4954  df-iun 5002  df-iin 5003  df-br 5153  df-opab 5215  df-mpt 5236  df-tr 5270  df-id 5580  df-eprel 5586  df-po 5594  df-so 5595  df-fr 5637  df-se 5638  df-we 5639  df-xp 5688  df-rel 5689  df-cnv 5690  df-co 5691  df-dm 5692  df-rn 5693  df-res 5694  df-ima 5695  df-pred 6310  df-ord 6377  df-on 6378  df-lim 6379  df-suc 6380  df-iota 6505  df-fun 6555  df-fn 6556  df-f 6557  df-f1 6558  df-fo 6559  df-f1o 6560  df-fv 6561  df-isom 6562  df-riota 7382  df-ov 7429  df-oprab 7430  df-mpo 7431  df-om 7879  df-1st 8001  df-2nd 8002  df-frecs 8295  df-wrecs 8326  df-recs 8400  df-rdg 8439  df-1o 8495  df-er 8733  df-map 8855  df-en 8973  df-dom 8974  df-sdom 8975  df-fin 8976  df-oi 9543  df-r1 9797  df-rank 9798  df-card 9972  df-acn 9975  df-ac 10149
This theorem is referenced by: (None)
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