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Mirrors > Home > MPE Home > Th. List > nnfi | Structured version Visualization version GIF version |
Description: Natural numbers are finite sets. (Contributed by Stefan O'Rear, 21-Mar-2015.) Avoid ax-pow 5370. (Revised by BTernaryTau, 23-Sep-2024.) |
Ref | Expression |
---|---|
nnfi | ⊢ (𝐴 ∈ ω → 𝐴 ∈ Fin) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | enrefnn 9085 | . . 3 ⊢ (𝐴 ∈ ω → 𝐴 ≈ 𝐴) | |
2 | breq2 5151 | . . . 4 ⊢ (𝑥 = 𝐴 → (𝐴 ≈ 𝑥 ↔ 𝐴 ≈ 𝐴)) | |
3 | 2 | rspcev 3621 | . . 3 ⊢ ((𝐴 ∈ ω ∧ 𝐴 ≈ 𝐴) → ∃𝑥 ∈ ω 𝐴 ≈ 𝑥) |
4 | 1, 3 | mpdan 687 | . 2 ⊢ (𝐴 ∈ ω → ∃𝑥 ∈ ω 𝐴 ≈ 𝑥) |
5 | isfi 9014 | . 2 ⊢ (𝐴 ∈ Fin ↔ ∃𝑥 ∈ ω 𝐴 ≈ 𝑥) | |
6 | 4, 5 | sylibr 234 | 1 ⊢ (𝐴 ∈ ω → 𝐴 ∈ Fin) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∈ wcel 2105 ∃wrex 3067 class class class wbr 5147 ωcom 7886 ≈ cen 8980 Fincfn 8983 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1791 ax-4 1805 ax-5 1907 ax-6 1964 ax-7 2004 ax-8 2107 ax-9 2115 ax-10 2138 ax-12 2174 ax-ext 2705 ax-sep 5301 ax-nul 5311 ax-pr 5437 ax-un 7753 |
This theorem depends on definitions: df-bi 207 df-an 396 df-or 848 df-3or 1087 df-3an 1088 df-tru 1539 df-fal 1549 df-ex 1776 df-nf 1780 df-sb 2062 df-mo 2537 df-clab 2712 df-cleq 2726 df-clel 2813 df-ne 2938 df-ral 3059 df-rex 3068 df-rab 3433 df-v 3479 df-dif 3965 df-un 3967 df-in 3969 df-ss 3979 df-pss 3982 df-nul 4339 df-if 4531 df-pw 4606 df-sn 4631 df-pr 4633 df-op 4637 df-uni 4912 df-br 5148 df-opab 5210 df-tr 5265 df-id 5582 df-eprel 5588 df-po 5596 df-so 5597 df-fr 5640 df-we 5642 df-xp 5694 df-rel 5695 df-cnv 5696 df-co 5697 df-dm 5698 df-rn 5699 df-ord 6388 df-on 6389 df-lim 6390 df-suc 6391 df-fun 6564 df-fn 6565 df-f 6566 df-f1 6567 df-fo 6568 df-f1o 6569 df-om 7887 df-en 8984 df-fin 8987 |
This theorem is referenced by: ssnnfi 9207 enfii 9223 phplem1 9241 phplem2 9242 php 9244 php2 9245 php3 9246 nndomog 9250 onomeneq 9262 sucdom 9268 ominf 9291 findcard3 9315 nnsdomg 9332 infsdomnn 9335 fiint 9363 cardnn 10000 en2eqpr 10044 en2eleq 10045 infxpenlem 10050 dfac12k 10185 ficardadju 10237 pwsdompw 10240 ackbij2lem1 10255 ackbij1lem3 10258 ackbij1lem5 10260 ackbij1lem14 10269 ackbij1b 10275 fin23lem23 10363 fin23lem22 10364 domtriomlem 10479 gchdju1 10693 gch2 10712 omina 10728 hashgval2 14413 hashdom 14414 hashp1i 14438 hash1snb 14454 hash2pr 14504 pr2pwpr 14514 hash3tr 14526 xpsfrnel 17608 symggen 19502 psgnunilem1 19525 lt6abl 19927 simpgnsgd 20134 znfld 21596 frgpcyg 21609 xpsmet 24407 xpsxms 24562 xpsms 24563 isppw 27171 madefi 27964 oldfi 27965 unidifsnel 32560 unidifsnne 32561 finxpreclem4 37376 harinf 43022 frlmpwfi 43086 cantnfub2 43311 infordmin 43521 |
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