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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 10106 | . 2 ⊢ ((𝐴 ∈ Inaccw ∧ 𝐴 ≠ ω) → ∃𝑥((ℵ‘𝑥) = 𝐴 ∧ Lim 𝑥)) | |
2 | vex 3495 | . . . . . . . . 9 ⊢ 𝑥 ∈ V | |
3 | limelon 6247 | . . . . . . . . 9 ⊢ ((𝑥 ∈ V ∧ Lim 𝑥) → 𝑥 ∈ On) | |
4 | 2, 3 | mpan 686 | . . . . . . . 8 ⊢ (Lim 𝑥 → 𝑥 ∈ On) |
5 | alephle 9502 | . . . . . . . 8 ⊢ (𝑥 ∈ On → 𝑥 ⊆ (ℵ‘𝑥)) | |
6 | 4, 5 | syl 17 | . . . . . . 7 ⊢ (Lim 𝑥 → 𝑥 ⊆ (ℵ‘𝑥)) |
7 | 6 | ad2antll 725 | . . . . . 6 ⊢ (((𝐴 ∈ Inaccw ∧ 𝐴 ≠ ω) ∧ ((ℵ‘𝑥) = 𝐴 ∧ Lim 𝑥)) → 𝑥 ⊆ (ℵ‘𝑥)) |
8 | simprl 767 | . . . . . 6 ⊢ (((𝐴 ∈ Inaccw ∧ 𝐴 ≠ ω) ∧ ((ℵ‘𝑥) = 𝐴 ∧ Lim 𝑥)) → (ℵ‘𝑥) = 𝐴) | |
9 | 7, 8 | sseqtrd 4004 | . . . . 5 ⊢ (((𝐴 ∈ Inaccw ∧ 𝐴 ≠ ω) ∧ ((ℵ‘𝑥) = 𝐴 ∧ Lim 𝑥)) → 𝑥 ⊆ 𝐴) |
10 | 8 | fveq2d 6667 | . . . . . . . 8 ⊢ (((𝐴 ∈ Inaccw ∧ 𝐴 ≠ ω) ∧ ((ℵ‘𝑥) = 𝐴 ∧ Lim 𝑥)) → (cf‘(ℵ‘𝑥)) = (cf‘𝐴)) |
11 | alephsing 9686 | . . . . . . . . 9 ⊢ (Lim 𝑥 → (cf‘(ℵ‘𝑥)) = (cf‘𝑥)) | |
12 | 11 | ad2antll 725 | . . . . . . . 8 ⊢ (((𝐴 ∈ Inaccw ∧ 𝐴 ≠ ω) ∧ ((ℵ‘𝑥) = 𝐴 ∧ Lim 𝑥)) → (cf‘(ℵ‘𝑥)) = (cf‘𝑥)) |
13 | 10, 12 | eqtr3d 2855 | . . . . . . 7 ⊢ (((𝐴 ∈ Inaccw ∧ 𝐴 ≠ ω) ∧ ((ℵ‘𝑥) = 𝐴 ∧ Lim 𝑥)) → (cf‘𝐴) = (cf‘𝑥)) |
14 | elwina 10096 | . . . . . . . . 9 ⊢ (𝐴 ∈ Inaccw ↔ (𝐴 ≠ ∅ ∧ (cf‘𝐴) = 𝐴 ∧ ∀𝑦 ∈ 𝐴 ∃𝑧 ∈ 𝐴 𝑦 ≺ 𝑧)) | |
15 | 14 | simp2bi 1138 | . . . . . . . 8 ⊢ (𝐴 ∈ Inaccw → (cf‘𝐴) = 𝐴) |
16 | 15 | ad2antrr 722 | . . . . . . 7 ⊢ (((𝐴 ∈ Inaccw ∧ 𝐴 ≠ ω) ∧ ((ℵ‘𝑥) = 𝐴 ∧ Lim 𝑥)) → (cf‘𝐴) = 𝐴) |
17 | 13, 16 | eqtr3d 2855 | . . . . . 6 ⊢ (((𝐴 ∈ Inaccw ∧ 𝐴 ≠ ω) ∧ ((ℵ‘𝑥) = 𝐴 ∧ Lim 𝑥)) → (cf‘𝑥) = 𝐴) |
18 | cfle 9664 | . . . . . 6 ⊢ (cf‘𝑥) ⊆ 𝑥 | |
19 | 17, 18 | eqsstrrdi 4019 | . . . . 5 ⊢ (((𝐴 ∈ Inaccw ∧ 𝐴 ≠ ω) ∧ ((ℵ‘𝑥) = 𝐴 ∧ Lim 𝑥)) → 𝐴 ⊆ 𝑥) |
20 | 9, 19 | eqssd 3981 | . . . 4 ⊢ (((𝐴 ∈ Inaccw ∧ 𝐴 ≠ ω) ∧ ((ℵ‘𝑥) = 𝐴 ∧ Lim 𝑥)) → 𝑥 = 𝐴) |
21 | 20 | fveq2d 6667 | . . 3 ⊢ (((𝐴 ∈ Inaccw ∧ 𝐴 ≠ ω) ∧ ((ℵ‘𝑥) = 𝐴 ∧ Lim 𝑥)) → (ℵ‘𝑥) = (ℵ‘𝐴)) |
22 | 21, 8 | eqtr3d 2855 | . 2 ⊢ (((𝐴 ∈ Inaccw ∧ 𝐴 ≠ ω) ∧ ((ℵ‘𝑥) = 𝐴 ∧ Lim 𝑥)) → (ℵ‘𝐴) = 𝐴) |
23 | 1, 22 | exlimddv 1927 | 1 ⊢ ((𝐴 ∈ Inaccw ∧ 𝐴 ≠ ω) → (ℵ‘𝐴) = 𝐴) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 396 = wceq 1528 ∈ wcel 2105 ≠ wne 3013 ∀wral 3135 ∃wrex 3136 Vcvv 3492 ⊆ wss 3933 ∅c0 4288 class class class wbr 5057 Oncon0 6184 Lim wlim 6185 ‘cfv 6348 ωcom 7569 ≺ csdm 8496 ℵcale 9353 cfccf 9354 Inaccwcwina 10092 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1787 ax-4 1801 ax-5 1902 ax-6 1961 ax-7 2006 ax-8 2107 ax-9 2115 ax-10 2136 ax-11 2151 ax-12 2167 ax-ext 2790 ax-rep 5181 ax-sep 5194 ax-nul 5201 ax-pow 5257 ax-pr 5320 ax-un 7450 ax-inf2 9092 |
This theorem depends on definitions: df-bi 208 df-an 397 df-or 842 df-3or 1080 df-3an 1081 df-tru 1531 df-ex 1772 df-nf 1776 df-sb 2061 df-mo 2615 df-eu 2647 df-clab 2797 df-cleq 2811 df-clel 2890 df-nfc 2960 df-ne 3014 df-ral 3140 df-rex 3141 df-reu 3142 df-rmo 3143 df-rab 3144 df-v 3494 df-sbc 3770 df-csb 3881 df-dif 3936 df-un 3938 df-in 3940 df-ss 3949 df-pss 3951 df-nul 4289 df-if 4464 df-pw 4537 df-sn 4558 df-pr 4560 df-tp 4562 df-op 4564 df-uni 4831 df-int 4868 df-iun 4912 df-br 5058 df-opab 5120 df-mpt 5138 df-tr 5164 df-id 5453 df-eprel 5458 df-po 5467 df-so 5468 df-fr 5507 df-se 5508 df-we 5509 df-xp 5554 df-rel 5555 df-cnv 5556 df-co 5557 df-dm 5558 df-rn 5559 df-res 5560 df-ima 5561 df-pred 6141 df-ord 6187 df-on 6188 df-lim 6189 df-suc 6190 df-iota 6307 df-fun 6350 df-fn 6351 df-f 6352 df-f1 6353 df-fo 6354 df-f1o 6355 df-fv 6356 df-isom 6357 df-riota 7103 df-ov 7148 df-oprab 7149 df-mpo 7150 df-om 7570 df-1st 7678 df-2nd 7679 df-wrecs 7936 df-smo 7972 df-recs 7997 df-rdg 8035 df-er 8278 df-map 8397 df-en 8498 df-dom 8499 df-sdom 8500 df-fin 8501 df-oi 8962 df-har 9010 df-card 9356 df-aleph 9357 df-cf 9358 df-acn 9359 df-wina 10094 |
This theorem is referenced by: winafpi 10108 |
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