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Mirrors > Home > MPE Home > Th. List > domfi | Structured version Visualization version GIF version |
Description: A set dominated by a finite set is finite. (Contributed by NM, 23-Mar-2006.) (Revised by Mario Carneiro, 12-Mar-2015.) |
Ref | Expression |
---|---|
domfi | ⊢ ((𝐴 ∈ Fin ∧ 𝐵 ≼ 𝐴) → 𝐵 ∈ Fin) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | domeng 8954 | . . 3 ⊢ (𝐴 ∈ Fin → (𝐵 ≼ 𝐴 ↔ ∃𝑥(𝐵 ≈ 𝑥 ∧ 𝑥 ⊆ 𝐴))) | |
2 | ssfi 9169 | . . . . . . 7 ⊢ ((𝐴 ∈ Fin ∧ 𝑥 ⊆ 𝐴) → 𝑥 ∈ Fin) | |
3 | 2 | adantrl 714 | . . . . . 6 ⊢ ((𝐴 ∈ Fin ∧ (𝐵 ≈ 𝑥 ∧ 𝑥 ⊆ 𝐴)) → 𝑥 ∈ Fin) |
4 | enfii 9185 | . . . . . . 7 ⊢ ((𝑥 ∈ Fin ∧ 𝐵 ≈ 𝑥) → 𝐵 ∈ Fin) | |
5 | 4 | adantrr 715 | . . . . . 6 ⊢ ((𝑥 ∈ Fin ∧ (𝐵 ≈ 𝑥 ∧ 𝑥 ⊆ 𝐴)) → 𝐵 ∈ Fin) |
6 | 3, 5 | sylancom 588 | . . . . 5 ⊢ ((𝐴 ∈ Fin ∧ (𝐵 ≈ 𝑥 ∧ 𝑥 ⊆ 𝐴)) → 𝐵 ∈ Fin) |
7 | 6 | ex 413 | . . . 4 ⊢ (𝐴 ∈ Fin → ((𝐵 ≈ 𝑥 ∧ 𝑥 ⊆ 𝐴) → 𝐵 ∈ Fin)) |
8 | 7 | exlimdv 1936 | . . 3 ⊢ (𝐴 ∈ Fin → (∃𝑥(𝐵 ≈ 𝑥 ∧ 𝑥 ⊆ 𝐴) → 𝐵 ∈ Fin)) |
9 | 1, 8 | sylbid 239 | . 2 ⊢ (𝐴 ∈ Fin → (𝐵 ≼ 𝐴 → 𝐵 ∈ Fin)) |
10 | 9 | imp 407 | 1 ⊢ ((𝐴 ∈ Fin ∧ 𝐵 ≼ 𝐴) → 𝐵 ∈ Fin) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 396 ∃wex 1781 ∈ wcel 2106 ⊆ wss 3947 class class class wbr 5147 ≈ cen 8932 ≼ cdom 8933 Fincfn 8935 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1797 ax-4 1811 ax-5 1913 ax-6 1971 ax-7 2011 ax-8 2108 ax-9 2116 ax-10 2137 ax-11 2154 ax-12 2171 ax-ext 2703 ax-sep 5298 ax-nul 5305 ax-pr 5426 ax-un 7721 |
This theorem depends on definitions: df-bi 206 df-an 397 df-or 846 df-3or 1088 df-3an 1089 df-tru 1544 df-fal 1554 df-ex 1782 df-nf 1786 df-sb 2068 df-mo 2534 df-eu 2563 df-clab 2710 df-cleq 2724 df-clel 2810 df-nfc 2885 df-ne 2941 df-ral 3062 df-rex 3071 df-reu 3377 df-rab 3433 df-v 3476 df-sbc 3777 df-dif 3950 df-un 3952 df-in 3954 df-ss 3964 df-pss 3966 df-nul 4322 df-if 4528 df-pw 4603 df-sn 4628 df-pr 4630 df-op 4634 df-uni 4908 df-br 5148 df-opab 5210 df-tr 5265 df-id 5573 df-eprel 5579 df-po 5587 df-so 5588 df-fr 5630 df-we 5632 df-xp 5681 df-rel 5682 df-cnv 5683 df-co 5684 df-dm 5685 df-rn 5686 df-res 5687 df-ima 5688 df-ord 6364 df-on 6365 df-lim 6366 df-suc 6367 df-iota 6492 df-fun 6542 df-fn 6543 df-f 6544 df-f1 6545 df-fo 6546 df-f1o 6547 df-fv 6548 df-om 7852 df-1o 8462 df-en 8936 df-dom 8937 df-fin 8939 |
This theorem is referenced by: domtrfi 9192 domtrfir 9193 sdomdomtrfi 9200 php3 9208 onomeneq 9224 xpfir 9262 findcard3 9281 dmfi 9326 fofi 9334 pwfilemOLD 9342 pwfiOLD 9343 sdom2en01 10293 isfin1-2 10376 fin67 10386 fin1a2lem9 10399 gchdju1 10647 hashdomi 14336 symggen 19332 cmpsub 22895 ufinffr 23424 alexsubALT 23546 ovolicc2lem4 25028 aannenlem1 25832 ffsrn 31941 locfinreflem 32808 lindsenlbs 36471 harinf 41758 kelac2lem 41791 disjinfi 43876 |
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