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Mirrors > Home > MPE Home > Th. List > winafp | Structured version Visualization version GIF version |
Description: A nontrivial weakly inaccessible cardinal is a fixed point of the aleph function. (Contributed by Mario Carneiro, 29-May-2014.) |
Ref | Expression |
---|---|
winafp | ⊢ ((𝐴 ∈ Inaccw ∧ 𝐴 ≠ ω) → (ℵ‘𝐴) = 𝐴) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | winalim2 10639 | . 2 ⊢ ((𝐴 ∈ Inaccw ∧ 𝐴 ≠ ω) → ∃𝑥((ℵ‘𝑥) = 𝐴 ∧ Lim 𝑥)) | |
2 | vex 3452 | . . . . . . . . 9 ⊢ 𝑥 ∈ V | |
3 | limelon 6386 | . . . . . . . . 9 ⊢ ((𝑥 ∈ V ∧ Lim 𝑥) → 𝑥 ∈ On) | |
4 | 2, 3 | mpan 689 | . . . . . . . 8 ⊢ (Lim 𝑥 → 𝑥 ∈ On) |
5 | alephle 10031 | . . . . . . . 8 ⊢ (𝑥 ∈ On → 𝑥 ⊆ (ℵ‘𝑥)) | |
6 | 4, 5 | syl 17 | . . . . . . 7 ⊢ (Lim 𝑥 → 𝑥 ⊆ (ℵ‘𝑥)) |
7 | 6 | ad2antll 728 | . . . . . 6 ⊢ (((𝐴 ∈ Inaccw ∧ 𝐴 ≠ ω) ∧ ((ℵ‘𝑥) = 𝐴 ∧ Lim 𝑥)) → 𝑥 ⊆ (ℵ‘𝑥)) |
8 | simprl 770 | . . . . . 6 ⊢ (((𝐴 ∈ Inaccw ∧ 𝐴 ≠ ω) ∧ ((ℵ‘𝑥) = 𝐴 ∧ Lim 𝑥)) → (ℵ‘𝑥) = 𝐴) | |
9 | 7, 8 | sseqtrd 3989 | . . . . 5 ⊢ (((𝐴 ∈ Inaccw ∧ 𝐴 ≠ ω) ∧ ((ℵ‘𝑥) = 𝐴 ∧ Lim 𝑥)) → 𝑥 ⊆ 𝐴) |
10 | 8 | fveq2d 6851 | . . . . . . . 8 ⊢ (((𝐴 ∈ Inaccw ∧ 𝐴 ≠ ω) ∧ ((ℵ‘𝑥) = 𝐴 ∧ Lim 𝑥)) → (cf‘(ℵ‘𝑥)) = (cf‘𝐴)) |
11 | alephsing 10219 | . . . . . . . . 9 ⊢ (Lim 𝑥 → (cf‘(ℵ‘𝑥)) = (cf‘𝑥)) | |
12 | 11 | ad2antll 728 | . . . . . . . 8 ⊢ (((𝐴 ∈ Inaccw ∧ 𝐴 ≠ ω) ∧ ((ℵ‘𝑥) = 𝐴 ∧ Lim 𝑥)) → (cf‘(ℵ‘𝑥)) = (cf‘𝑥)) |
13 | 10, 12 | eqtr3d 2779 | . . . . . . 7 ⊢ (((𝐴 ∈ Inaccw ∧ 𝐴 ≠ ω) ∧ ((ℵ‘𝑥) = 𝐴 ∧ Lim 𝑥)) → (cf‘𝐴) = (cf‘𝑥)) |
14 | elwina 10629 | . . . . . . . . 9 ⊢ (𝐴 ∈ Inaccw ↔ (𝐴 ≠ ∅ ∧ (cf‘𝐴) = 𝐴 ∧ ∀𝑦 ∈ 𝐴 ∃𝑧 ∈ 𝐴 𝑦 ≺ 𝑧)) | |
15 | 14 | simp2bi 1147 | . . . . . . . 8 ⊢ (𝐴 ∈ Inaccw → (cf‘𝐴) = 𝐴) |
16 | 15 | ad2antrr 725 | . . . . . . 7 ⊢ (((𝐴 ∈ Inaccw ∧ 𝐴 ≠ ω) ∧ ((ℵ‘𝑥) = 𝐴 ∧ Lim 𝑥)) → (cf‘𝐴) = 𝐴) |
17 | 13, 16 | eqtr3d 2779 | . . . . . 6 ⊢ (((𝐴 ∈ Inaccw ∧ 𝐴 ≠ ω) ∧ ((ℵ‘𝑥) = 𝐴 ∧ Lim 𝑥)) → (cf‘𝑥) = 𝐴) |
18 | cfle 10197 | . . . . . 6 ⊢ (cf‘𝑥) ⊆ 𝑥 | |
19 | 17, 18 | eqsstrrdi 4004 | . . . . 5 ⊢ (((𝐴 ∈ Inaccw ∧ 𝐴 ≠ ω) ∧ ((ℵ‘𝑥) = 𝐴 ∧ Lim 𝑥)) → 𝐴 ⊆ 𝑥) |
20 | 9, 19 | eqssd 3966 | . . . 4 ⊢ (((𝐴 ∈ Inaccw ∧ 𝐴 ≠ ω) ∧ ((ℵ‘𝑥) = 𝐴 ∧ Lim 𝑥)) → 𝑥 = 𝐴) |
21 | 20 | fveq2d 6851 | . . 3 ⊢ (((𝐴 ∈ Inaccw ∧ 𝐴 ≠ ω) ∧ ((ℵ‘𝑥) = 𝐴 ∧ Lim 𝑥)) → (ℵ‘𝑥) = (ℵ‘𝐴)) |
22 | 21, 8 | eqtr3d 2779 | . 2 ⊢ (((𝐴 ∈ Inaccw ∧ 𝐴 ≠ ω) ∧ ((ℵ‘𝑥) = 𝐴 ∧ Lim 𝑥)) → (ℵ‘𝐴) = 𝐴) |
23 | 1, 22 | exlimddv 1939 | 1 ⊢ ((𝐴 ∈ Inaccw ∧ 𝐴 ≠ ω) → (ℵ‘𝐴) = 𝐴) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 397 = wceq 1542 ∈ wcel 2107 ≠ wne 2944 ∀wral 3065 ∃wrex 3074 Vcvv 3448 ⊆ wss 3915 ∅c0 4287 class class class wbr 5110 Oncon0 6322 Lim wlim 6323 ‘cfv 6501 ωcom 7807 ≺ csdm 8889 ℵcale 9879 cfccf 9880 Inaccwcwina 10625 |
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 2708 ax-rep 5247 ax-sep 5261 ax-nul 5268 ax-pow 5325 ax-pr 5389 ax-un 7677 ax-inf2 9584 |
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 2539 df-eu 2568 df-clab 2715 df-cleq 2729 df-clel 2815 df-nfc 2890 df-ne 2945 df-ral 3066 df-rex 3075 df-rmo 3356 df-reu 3357 df-rab 3411 df-v 3450 df-sbc 3745 df-csb 3861 df-dif 3918 df-un 3920 df-in 3922 df-ss 3932 df-pss 3934 df-nul 4288 df-if 4492 df-pw 4567 df-sn 4592 df-pr 4594 df-op 4598 df-uni 4871 df-int 4913 df-iun 4961 df-br 5111 df-opab 5173 df-mpt 5194 df-tr 5228 df-id 5536 df-eprel 5542 df-po 5550 df-so 5551 df-fr 5593 df-se 5594 df-we 5595 df-xp 5644 df-rel 5645 df-cnv 5646 df-co 5647 df-dm 5648 df-rn 5649 df-res 5650 df-ima 5651 df-pred 6258 df-ord 6325 df-on 6326 df-lim 6327 df-suc 6328 df-iota 6453 df-fun 6503 df-fn 6504 df-f 6505 df-f1 6506 df-fo 6507 df-f1o 6508 df-fv 6509 df-isom 6510 df-riota 7318 df-ov 7365 df-oprab 7366 df-mpo 7367 df-om 7808 df-1st 7926 df-2nd 7927 df-frecs 8217 df-wrecs 8248 df-smo 8297 df-recs 8322 df-rdg 8361 df-1o 8417 df-er 8655 df-map 8774 df-en 8891 df-dom 8892 df-sdom 8893 df-fin 8894 df-oi 9453 df-har 9500 df-card 9882 df-aleph 9883 df-cf 9884 df-acn 9885 df-wina 10627 |
This theorem is referenced by: winafpi 10641 |
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