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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 9002 | . . 3 ⊢ (𝐴 ∈ Fin → (𝐵 ≼ 𝐴 ↔ ∃𝑥(𝐵 ≈ 𝑥 ∧ 𝑥 ⊆ 𝐴))) | |
2 | ssfi 9212 | . . . . . . 7 ⊢ ((𝐴 ∈ Fin ∧ 𝑥 ⊆ 𝐴) → 𝑥 ∈ Fin) | |
3 | 2 | adantrl 716 | . . . . . 6 ⊢ ((𝐴 ∈ Fin ∧ (𝐵 ≈ 𝑥 ∧ 𝑥 ⊆ 𝐴)) → 𝑥 ∈ Fin) |
4 | enfii 9224 | . . . . . . 7 ⊢ ((𝑥 ∈ Fin ∧ 𝐵 ≈ 𝑥) → 𝐵 ∈ Fin) | |
5 | 4 | adantrr 717 | . . . . . 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 412 | . . . 4 ⊢ (𝐴 ∈ Fin → ((𝐵 ≈ 𝑥 ∧ 𝑥 ⊆ 𝐴) → 𝐵 ∈ Fin)) |
8 | 7 | exlimdv 1931 | . . 3 ⊢ (𝐴 ∈ Fin → (∃𝑥(𝐵 ≈ 𝑥 ∧ 𝑥 ⊆ 𝐴) → 𝐵 ∈ Fin)) |
9 | 1, 8 | sylbid 240 | . 2 ⊢ (𝐴 ∈ Fin → (𝐵 ≼ 𝐴 → 𝐵 ∈ Fin)) |
10 | 9 | imp 406 | 1 ⊢ ((𝐴 ∈ Fin ∧ 𝐵 ≼ 𝐴) → 𝐵 ∈ Fin) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 395 ∃wex 1776 ∈ wcel 2106 ⊆ wss 3963 class class class wbr 5148 ≈ cen 8981 ≼ cdom 8982 Fincfn 8984 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1792 ax-4 1806 ax-5 1908 ax-6 1965 ax-7 2005 ax-8 2108 ax-9 2116 ax-10 2139 ax-11 2155 ax-12 2175 ax-ext 2706 ax-sep 5302 ax-nul 5312 ax-pr 5438 ax-un 7754 |
This theorem depends on definitions: df-bi 207 df-an 396 df-or 848 df-3or 1087 df-3an 1088 df-tru 1540 df-fal 1550 df-ex 1777 df-nf 1781 df-sb 2063 df-mo 2538 df-eu 2567 df-clab 2713 df-cleq 2727 df-clel 2814 df-nfc 2890 df-ne 2939 df-ral 3060 df-rex 3069 df-reu 3379 df-rab 3434 df-v 3480 df-sbc 3792 df-dif 3966 df-un 3968 df-in 3970 df-ss 3980 df-pss 3983 df-nul 4340 df-if 4532 df-pw 4607 df-sn 4632 df-pr 4634 df-op 4638 df-uni 4913 df-br 5149 df-opab 5211 df-tr 5266 df-id 5583 df-eprel 5589 df-po 5597 df-so 5598 df-fr 5641 df-we 5643 df-xp 5695 df-rel 5696 df-cnv 5697 df-co 5698 df-dm 5699 df-rn 5700 df-res 5701 df-ima 5702 df-ord 6389 df-on 6390 df-lim 6391 df-suc 6392 df-iota 6516 df-fun 6565 df-fn 6566 df-f 6567 df-f1 6568 df-fo 6569 df-f1o 6570 df-fv 6571 df-om 7888 df-1o 8505 df-en 8985 df-dom 8986 df-fin 8988 |
This theorem is referenced by: domtrfi 9231 domtrfir 9232 sdomdomtrfi 9239 php3 9247 onomeneq 9263 xpfir 9298 findcard3 9316 fofi 9349 fodomfir 9366 dmfi 9373 sdom2en01 10340 isfin1-2 10423 fin67 10433 fin1a2lem9 10446 gchdju1 10694 hashdomi 14416 symggen 19503 cmpsub 23424 ufinffr 23953 alexsubALT 24075 ovolicc2lem4 25569 aannenlem1 26385 madefi 27965 ffsrn 32747 locfinreflem 33801 lindsenlbs 37602 harinf 43023 kelac2lem 43053 disjinfi 45135 |
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