![]() |
Mathbox for Richard Penner |
< Previous
Next >
Nearby theorems |
|
Mirrors > Home > MPE Home > Th. List > Mathboxes > aleph1min | Structured version Visualization version GIF version |
Description: (ℵ‘1o) is the least uncountable ordinal. (Contributed by RP, 18-Nov-2023.) |
Ref | Expression |
---|---|
aleph1min | ⊢ (ℵ‘1o) = ∩ {𝑥 ∈ On ∣ ω ≺ 𝑥} |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | df-1o 8505 | . . 3 ⊢ 1o = suc ∅ | |
2 | 1 | fveq2i 6910 | . 2 ⊢ (ℵ‘1o) = (ℵ‘suc ∅) |
3 | 0elon 6440 | . . . . 5 ⊢ ∅ ∈ On | |
4 | alephsuc 10106 | . . . . 5 ⊢ (∅ ∈ On → (ℵ‘suc ∅) = (har‘(ℵ‘∅))) | |
5 | 3, 4 | ax-mp 5 | . . . 4 ⊢ (ℵ‘suc ∅) = (har‘(ℵ‘∅)) |
6 | aleph0 10104 | . . . . 5 ⊢ (ℵ‘∅) = ω | |
7 | 6 | fveq2i 6910 | . . . 4 ⊢ (har‘(ℵ‘∅)) = (har‘ω) |
8 | 5, 7 | eqtri 2763 | . . 3 ⊢ (ℵ‘suc ∅) = (har‘ω) |
9 | omelon 9684 | . . . . 5 ⊢ ω ∈ On | |
10 | onenon 9987 | . . . . 5 ⊢ (ω ∈ On → ω ∈ dom card) | |
11 | 9, 10 | ax-mp 5 | . . . 4 ⊢ ω ∈ dom card |
12 | harval2 10035 | . . . 4 ⊢ (ω ∈ dom card → (har‘ω) = ∩ {𝑥 ∈ On ∣ ω ≺ 𝑥}) | |
13 | 11, 12 | ax-mp 5 | . . 3 ⊢ (har‘ω) = ∩ {𝑥 ∈ On ∣ ω ≺ 𝑥} |
14 | 8, 13 | eqtri 2763 | . 2 ⊢ (ℵ‘suc ∅) = ∩ {𝑥 ∈ On ∣ ω ≺ 𝑥} |
15 | 2, 14 | eqtri 2763 | 1 ⊢ (ℵ‘1o) = ∩ {𝑥 ∈ On ∣ ω ≺ 𝑥} |
Colors of variables: wff setvar class |
Syntax hints: = wceq 1537 ∈ wcel 2106 {crab 3433 ∅c0 4339 ∩ cint 4951 class class class wbr 5148 dom cdm 5689 Oncon0 6386 suc csuc 6388 ‘cfv 6563 ωcom 7887 1oc1o 8498 ≺ csdm 8983 harchar 9594 cardccrd 9973 ℵcale 9974 |
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-rep 5285 ax-sep 5302 ax-nul 5312 ax-pow 5371 ax-pr 5438 ax-un 7754 ax-inf2 9679 |
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-rmo 3378 df-reu 3379 df-rab 3434 df-v 3480 df-sbc 3792 df-csb 3909 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-int 4952 df-iun 4998 df-br 5149 df-opab 5211 df-mpt 5232 df-tr 5266 df-id 5583 df-eprel 5589 df-po 5597 df-so 5598 df-fr 5641 df-se 5642 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-pred 6323 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-isom 6572 df-riota 7388 df-ov 7434 df-om 7888 df-2nd 8014 df-frecs 8305 df-wrecs 8336 df-recs 8410 df-rdg 8449 df-1o 8505 df-er 8744 df-en 8985 df-dom 8986 df-sdom 8987 df-oi 9548 df-har 9595 df-card 9977 df-aleph 9978 |
This theorem is referenced by: (None) |
Copyright terms: Public domain | W3C validator |