fin34 - Metamath Proof Explorer

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Theorem fin34 10475

Description: Every III-finite set is IV-finite. (Contributed by Stefan O'Rear, 30-Oct-2014.)

**Assertion**
Ref	Expression
fin34	⊢ (𝐴 ∈ Fin^III → 𝐴 ∈ Fin^IV)

**Proof of Theorem fin34**
Step	Hyp	Ref	Expression
1		isfin3 10381	. . 3 ⊢ (𝐴 ∈ Fin^III ↔ 𝒫 𝐴 ∈ Fin^IV)
2		isfin4-2 10399	. . . . 5 ⊢ (𝒫 𝐴 ∈ Fin^IV → (𝒫 𝐴 ∈ Fin^IV ↔ ¬ ω ≼ 𝒫 𝐴))
3	2	ibi 270	. . . 4 ⊢ (𝒫 𝐴 ∈ Fin^IV → ¬ ω ≼ 𝒫 𝐴)
4		reldom 8987	. . . . . . . 8 ⊢ Rel ≼
5	4	brrelex2i 5708	. . . . . . 7 ⊢ (ω ≼ 𝐴 → 𝐴 ∈ V)
6		canth2g 9158	. . . . . . 7 ⊢ (𝐴 ∈ V → 𝐴 ≺ 𝒫 𝐴)
7	5, 6	syl 18	. . . . . 6 ⊢ (ω ≼ 𝐴 → 𝐴 ≺ 𝒫 𝐴)
8		domsdomtr 9139	. . . . . 6 ⊢ ((ω ≼ 𝐴 ∧ 𝐴 ≺ 𝒫 𝐴) → ω ≺ 𝒫 𝐴)
9	7, 8	mpdan 700	. . . . 5 ⊢ (ω ≼ 𝐴 → ω ≺ 𝒫 𝐴)
10		sdomdom 9015	. . . . 5 ⊢ (ω ≺ 𝒫 𝐴 → ω ≼ 𝒫 𝐴)
11	9, 10	syl 18	. . . 4 ⊢ (ω ≼ 𝐴 → ω ≼ 𝒫 𝐴)
12	3, 11	nsyl 141	. . 3 ⊢ (𝒫 𝐴 ∈ Fin^IV → ¬ ω ≼ 𝐴)
13	1, 12	sylbi 220	. 2 ⊢ (𝐴 ∈ Fin^III → ¬ ω ≼ 𝐴)
14		isfin4-2 10399	. 2 ⊢ (𝐴 ∈ Fin^III → (𝐴 ∈ Fin^IV ↔ ¬ ω ≼ 𝐴))
15	13, 14	mpbird 260	1 ⊢ (𝐴 ∈ Fin^III → 𝐴 ∈ Fin^IV)

Colors of variables: wff setvar class

This proof depends on syntax axioms: ¬ wn 3 → wi 4 ∈ wcel 2144 Vcvv 3450 𝒫 cpw 4556 class class class wbr 5102 ωcom 7881 ≼ cdom 8979 ≺ csdm 8980 Fin^IVcfin4 10365 Fin^IIIcfin3 10366

This proof depends on axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1827 ax-4 1841 ax-5 1942 ax-6 1999 ax-7 2040 ax-8 2146 ax-9 2154 ax-10 2177 ax-11 2193 ax-12 2212 ax-ext 2732 ax-rep 5231 ax-sep 5248 ax-nul 5259 ax-pow 5327 ax-pr 5391 ax-un 7755

This proof depends on definitions: df-bi 210 df-an 402 df-or 862 df-3or 1104 df-3an 1105 df-tru 1572 df-fal 1582 df-ex 1812 df-nf 1816 df-sb 2099 df-mo 2564 df-eu 2594 df-clab 2739 df-cleq 2752 df-clel 2835 df-nfc 2909 df-ne 2956 df-ral 3077 df-rex 3087 df-reu 3366 df-rab 3413 df-v 3452 df-sbc 3739 df-csb 3848 df-ss 3897 df-pss 4013 df-dif 4046 df-in 4090 df-un 4150 df-nul 4278 df-if 4482 df-pw 4558 df-sn 4585 df-pr 4587 df-op 4835 df-uni 4867 df-iun 4952 df-br 5103 df-opab 5167 df-mpt 5186 df-tr 5212 df-id 5546 df-eprel 5551 df-po 5559 df-so 5560 df-fr 5604 df-we 5606 df-xp 5657 df-rel 5658 df-cnv 5659 df-co 5660 df-dm 5661 df-rn 5662 df-res 5663 df-ima 5664 df-pred 6307 df-ord 6368 df-on 6369 df-lim 6370 df-suc 6371 df-iota 6497 df-fun 6545 df-fn 6546 df-f 6547 df-f1 6548 df-fo 6549 df-f1o 6550 df-fv 6551 df-ov 7427 df-om 7882 df-2nd 8006 df-frecs 8307 df-wrecs 8338 df-recs 8387 df-rdg 8426 df-er 8725 df-en 8982 df-dom 8983 df-sdom 8984 df-fin4 10372 df-fin3 10373

This theorem is used by: finngch 10747 infinfnum 35825 fin2so 38667

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