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Theorem cc2 7597
Description: Countable choice using sequences instead of countable sets. (Contributed by Jim Kingdon, 27-Apr-2024.)
Hypotheses
Ref Expression
cc2.cc (𝜑CCHOICE)
cc2.a (𝜑𝐹 Fn ω)
cc2.m (𝜑 → ∀𝑥 ∈ ω ∃𝑤 𝑤 ∈ (𝐹𝑥))
Assertion
Ref Expression
cc2 (𝜑 → ∃𝑔(𝑔 Fn ω ∧ ∀𝑛 ∈ ω (𝑔𝑛) ∈ (𝐹𝑛)))
Distinct variable groups:   𝑔,𝐹,𝑛   𝑤,𝐹,𝑥   𝜑,𝑛
Allowed substitution hints:   𝜑(𝑥,𝑤,𝑔)

Proof of Theorem cc2
Dummy variables 𝑓 𝑚 𝑣 𝑦 are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 cc2.cc . 2 (𝜑CCHOICE)
2 cc2.a . 2 (𝜑𝐹 Fn ω)
3 cc2.m . . . 4 (𝜑 → ∀𝑥 ∈ ω ∃𝑤 𝑤 ∈ (𝐹𝑥))
4 fveq2 5675 . . . . . . 7 (𝑥 = 𝑦 → (𝐹𝑥) = (𝐹𝑦))
54eleq2d 2304 . . . . . 6 (𝑥 = 𝑦 → (𝑤 ∈ (𝐹𝑥) ↔ 𝑤 ∈ (𝐹𝑦)))
65exbidv 1874 . . . . 5 (𝑥 = 𝑦 → (∃𝑤 𝑤 ∈ (𝐹𝑥) ↔ ∃𝑤 𝑤 ∈ (𝐹𝑦)))
76cbvralv 2780 . . . 4 (∀𝑥 ∈ ω ∃𝑤 𝑤 ∈ (𝐹𝑥) ↔ ∀𝑦 ∈ ω ∃𝑤 𝑤 ∈ (𝐹𝑦))
83, 7sylib 122 . . 3 (𝜑 → ∀𝑦 ∈ ω ∃𝑤 𝑤 ∈ (𝐹𝑦))
9 eleq1w 2295 . . . . 5 (𝑤 = 𝑣 → (𝑤 ∈ (𝐹𝑦) ↔ 𝑣 ∈ (𝐹𝑦)))
109cbvexv 1970 . . . 4 (∃𝑤 𝑤 ∈ (𝐹𝑦) ↔ ∃𝑣 𝑣 ∈ (𝐹𝑦))
1110ralbii 2550 . . 3 (∀𝑦 ∈ ω ∃𝑤 𝑤 ∈ (𝐹𝑦) ↔ ∀𝑦 ∈ ω ∃𝑣 𝑣 ∈ (𝐹𝑦))
128, 11sylib 122 . 2 (𝜑 → ∀𝑦 ∈ ω ∃𝑣 𝑣 ∈ (𝐹𝑦))
13 nfcv 2386 . . 3 𝑛({𝑚} × (𝐹𝑚))
14 nfcv 2386 . . 3 𝑚({𝑛} × (𝐹𝑛))
15 sneq 3705 . . . 4 (𝑚 = 𝑛 → {𝑚} = {𝑛})
16 fveq2 5675 . . . 4 (𝑚 = 𝑛 → (𝐹𝑚) = (𝐹𝑛))
1715, 16xpeq12d 4779 . . 3 (𝑚 = 𝑛 → ({𝑚} × (𝐹𝑚)) = ({𝑛} × (𝐹𝑛)))
1813, 14, 17cbvmpt 4210 . 2 (𝑚 ∈ ω ↦ ({𝑚} × (𝐹𝑚))) = (𝑛 ∈ ω ↦ ({𝑛} × (𝐹𝑛)))
19 nfcv 2386 . . 3 𝑛(2nd ‘(𝑓‘((𝑚 ∈ ω ↦ ({𝑚} × (𝐹𝑚)))‘𝑚)))
20 nfcv 2386 . . . 4 𝑚2nd
21 nfcv 2386 . . . . 5 𝑚𝑓
22 nffvmpt1 5686 . . . . 5 𝑚((𝑚 ∈ ω ↦ ({𝑚} × (𝐹𝑚)))‘𝑛)
2321, 22nffv 5685 . . . 4 𝑚(𝑓‘((𝑚 ∈ ω ↦ ({𝑚} × (𝐹𝑚)))‘𝑛))
2420, 23nffv 5685 . . 3 𝑚(2nd ‘(𝑓‘((𝑚 ∈ ω ↦ ({𝑚} × (𝐹𝑚)))‘𝑛)))
25 2fveq3 5680 . . . 4 (𝑚 = 𝑛 → (𝑓‘((𝑚 ∈ ω ↦ ({𝑚} × (𝐹𝑚)))‘𝑚)) = (𝑓‘((𝑚 ∈ ω ↦ ({𝑚} × (𝐹𝑚)))‘𝑛)))
2625fveq2d 5679 . . 3 (𝑚 = 𝑛 → (2nd ‘(𝑓‘((𝑚 ∈ ω ↦ ({𝑚} × (𝐹𝑚)))‘𝑚))) = (2nd ‘(𝑓‘((𝑚 ∈ ω ↦ ({𝑚} × (𝐹𝑚)))‘𝑛))))
2719, 24, 26cbvmpt 4210 . 2 (𝑚 ∈ ω ↦ (2nd ‘(𝑓‘((𝑚 ∈ ω ↦ ({𝑚} × (𝐹𝑚)))‘𝑚)))) = (𝑛 ∈ ω ↦ (2nd ‘(𝑓‘((𝑚 ∈ ω ↦ ({𝑚} × (𝐹𝑚)))‘𝑛))))
281, 2, 12, 18, 27cc2lem 7596 1 (𝜑 → ∃𝑔(𝑔 Fn ω ∧ ∀𝑛 ∈ ω (𝑔𝑛) ∈ (𝐹𝑛)))
Colors of variables: wff set class
Syntax hints:  wi 4  wa 104  wex 1541  wcel 2205  wral 2522  {csn 3694  cmpt 4176  ωcom 4717   × cxp 4752   Fn wfn 5352  cfv 5357  2nd c2nd 6346  CCHOICEwacc 7592
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 717  ax-5 1496  ax-7 1497  ax-gen 1498  ax-ie1 1542  ax-ie2 1543  ax-8 1553  ax-10 1554  ax-11 1555  ax-i12 1556  ax-bndl 1558  ax-4 1559  ax-17 1575  ax-i9 1579  ax-ial 1583  ax-i5r 1584  ax-13 2207  ax-14 2208  ax-ext 2216  ax-coll 4230  ax-sep 4233  ax-pow 4292  ax-pr 4327  ax-un 4559  ax-iinf 4715
This theorem depends on definitions:  df-bi 117  df-3an 1007  df-tru 1401  df-nf 1510  df-sb 1812  df-eu 2085  df-mo 2086  df-clab 2221  df-cleq 2227  df-clel 2230  df-nfc 2375  df-ral 2527  df-rex 2528  df-reu 2529  df-rab 2531  df-v 2817  df-sbc 3046  df-csb 3142  df-un 3218  df-in 3220  df-ss 3227  df-pw 3676  df-sn 3700  df-pr 3701  df-op 3703  df-uni 3920  df-int 3955  df-iun 3998  df-br 4115  df-opab 4177  df-mpt 4178  df-id 4419  df-iom 4718  df-xp 4760  df-rel 4761  df-cnv 4762  df-co 4763  df-dm 4764  df-rn 4765  df-res 4766  df-ima 4767  df-iota 5317  df-fun 5359  df-fn 5360  df-f 5361  df-f1 5362  df-fo 5363  df-f1o 5364  df-fv 5365  df-2nd 6348  df-er 6780  df-en 6989  df-cc 7593
This theorem is referenced by:  cc3  7598  acnccim  7602
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