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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 8905 | . . 3 ⊢ (𝐴 ∈ Fin → (𝐵 ≼ 𝐴 ↔ ∃𝑥(𝐵 ≈ 𝑥 ∧ 𝑥 ⊆ 𝐴))) | |
2 | ssfi 9120 | . . . . . . 7 ⊢ ((𝐴 ∈ Fin ∧ 𝑥 ⊆ 𝐴) → 𝑥 ∈ Fin) | |
3 | 2 | adantrl 715 | . . . . . 6 ⊢ ((𝐴 ∈ Fin ∧ (𝐵 ≈ 𝑥 ∧ 𝑥 ⊆ 𝐴)) → 𝑥 ∈ Fin) |
4 | enfii 9136 | . . . . . . 7 ⊢ ((𝑥 ∈ Fin ∧ 𝐵 ≈ 𝑥) → 𝐵 ∈ Fin) | |
5 | 4 | adantrr 716 | . . . . . 6 ⊢ ((𝑥 ∈ Fin ∧ (𝐵 ≈ 𝑥 ∧ 𝑥 ⊆ 𝐴)) → 𝐵 ∈ Fin) |
6 | 3, 5 | sylancom 589 | . . . . 5 ⊢ ((𝐴 ∈ Fin ∧ (𝐵 ≈ 𝑥 ∧ 𝑥 ⊆ 𝐴)) → 𝐵 ∈ Fin) |
7 | 6 | ex 414 | . . . 4 ⊢ (𝐴 ∈ Fin → ((𝐵 ≈ 𝑥 ∧ 𝑥 ⊆ 𝐴) → 𝐵 ∈ Fin)) |
8 | 7 | exlimdv 1937 | . . 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 408 | 1 ⊢ ((𝐴 ∈ Fin ∧ 𝐵 ≼ 𝐴) → 𝐵 ∈ Fin) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 397 ∃wex 1782 ∈ wcel 2107 ⊆ wss 3911 class class class wbr 5106 ≈ cen 8883 ≼ cdom 8884 Fincfn 8886 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1798 ax-4 1812 ax-5 1914 ax-6 1972 ax-7 2012 ax-8 2109 ax-9 2117 ax-10 2138 ax-11 2155 ax-12 2172 ax-ext 2704 ax-sep 5257 ax-nul 5264 ax-pr 5385 ax-un 7673 |
This theorem depends on definitions: df-bi 206 df-an 398 df-or 847 df-3or 1089 df-3an 1090 df-tru 1545 df-fal 1555 df-ex 1783 df-nf 1787 df-sb 2069 df-mo 2535 df-eu 2564 df-clab 2711 df-cleq 2725 df-clel 2811 df-nfc 2886 df-ne 2941 df-ral 3062 df-rex 3071 df-reu 3353 df-rab 3407 df-v 3446 df-sbc 3741 df-dif 3914 df-un 3916 df-in 3918 df-ss 3928 df-pss 3930 df-nul 4284 df-if 4488 df-pw 4563 df-sn 4588 df-pr 4590 df-op 4594 df-uni 4867 df-br 5107 df-opab 5169 df-tr 5224 df-id 5532 df-eprel 5538 df-po 5546 df-so 5547 df-fr 5589 df-we 5591 df-xp 5640 df-rel 5641 df-cnv 5642 df-co 5643 df-dm 5644 df-rn 5645 df-res 5646 df-ima 5647 df-ord 6321 df-on 6322 df-lim 6323 df-suc 6324 df-iota 6449 df-fun 6499 df-fn 6500 df-f 6501 df-f1 6502 df-fo 6503 df-f1o 6504 df-fv 6505 df-om 7804 df-1o 8413 df-en 8887 df-dom 8888 df-fin 8890 |
This theorem is referenced by: domtrfi 9143 domtrfir 9144 sdomdomtrfi 9151 php3 9159 onomeneq 9175 xpfir 9213 findcard3 9232 dmfi 9277 fofi 9285 pwfilemOLD 9293 pwfiOLD 9294 sdom2en01 10243 isfin1-2 10326 fin67 10336 fin1a2lem9 10349 gchdju1 10597 hashdomi 14286 symggen 19257 cmpsub 22767 ufinffr 23296 alexsubALT 23418 ovolicc2lem4 24900 aannenlem1 25704 ffsrn 31693 locfinreflem 32478 lindsenlbs 36119 harinf 41401 kelac2lem 41434 disjinfi 43500 |
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