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Mirrors > Home > MPE Home > Th. List > ordzsl | Structured version Visualization version GIF version |
Description: An ordinal is zero, a successor ordinal, or a limit ordinal. Remark 1.12 of [Schloeder] p. 2. (Contributed by NM, 1-Oct-2003.) |
Ref | Expression |
---|---|
ordzsl | ⊢ (Ord 𝐴 ↔ (𝐴 = ∅ ∨ ∃𝑥 ∈ On 𝐴 = suc 𝑥 ∨ Lim 𝐴)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | orduninsuc 7847 | . . . . . 6 ⊢ (Ord 𝐴 → (𝐴 = ∪ 𝐴 ↔ ¬ ∃𝑥 ∈ On 𝐴 = suc 𝑥)) | |
2 | 1 | biimprd 247 | . . . . 5 ⊢ (Ord 𝐴 → (¬ ∃𝑥 ∈ On 𝐴 = suc 𝑥 → 𝐴 = ∪ 𝐴)) |
3 | unizlim 6492 | . . . . 5 ⊢ (Ord 𝐴 → (𝐴 = ∪ 𝐴 ↔ (𝐴 = ∅ ∨ Lim 𝐴))) | |
4 | 2, 3 | sylibd 238 | . . . 4 ⊢ (Ord 𝐴 → (¬ ∃𝑥 ∈ On 𝐴 = suc 𝑥 → (𝐴 = ∅ ∨ Lim 𝐴))) |
5 | 4 | orrd 862 | . . 3 ⊢ (Ord 𝐴 → (∃𝑥 ∈ On 𝐴 = suc 𝑥 ∨ (𝐴 = ∅ ∨ Lim 𝐴))) |
6 | 3orass 1088 | . . . 4 ⊢ ((𝐴 = ∅ ∨ ∃𝑥 ∈ On 𝐴 = suc 𝑥 ∨ Lim 𝐴) ↔ (𝐴 = ∅ ∨ (∃𝑥 ∈ On 𝐴 = suc 𝑥 ∨ Lim 𝐴))) | |
7 | or12 919 | . . . 4 ⊢ ((𝐴 = ∅ ∨ (∃𝑥 ∈ On 𝐴 = suc 𝑥 ∨ Lim 𝐴)) ↔ (∃𝑥 ∈ On 𝐴 = suc 𝑥 ∨ (𝐴 = ∅ ∨ Lim 𝐴))) | |
8 | 6, 7 | bitri 275 | . . 3 ⊢ ((𝐴 = ∅ ∨ ∃𝑥 ∈ On 𝐴 = suc 𝑥 ∨ Lim 𝐴) ↔ (∃𝑥 ∈ On 𝐴 = suc 𝑥 ∨ (𝐴 = ∅ ∨ Lim 𝐴))) |
9 | 5, 8 | sylibr 233 | . 2 ⊢ (Ord 𝐴 → (𝐴 = ∅ ∨ ∃𝑥 ∈ On 𝐴 = suc 𝑥 ∨ Lim 𝐴)) |
10 | ord0 6422 | . . . 4 ⊢ Ord ∅ | |
11 | ordeq 6376 | . . . 4 ⊢ (𝐴 = ∅ → (Ord 𝐴 ↔ Ord ∅)) | |
12 | 10, 11 | mpbiri 258 | . . 3 ⊢ (𝐴 = ∅ → Ord 𝐴) |
13 | onsuc 7814 | . . . . . 6 ⊢ (𝑥 ∈ On → suc 𝑥 ∈ On) | |
14 | eleq1 2817 | . . . . . 6 ⊢ (𝐴 = suc 𝑥 → (𝐴 ∈ On ↔ suc 𝑥 ∈ On)) | |
15 | 13, 14 | imbitrrid 245 | . . . . 5 ⊢ (𝐴 = suc 𝑥 → (𝑥 ∈ On → 𝐴 ∈ On)) |
16 | eloni 6379 | . . . . 5 ⊢ (𝐴 ∈ On → Ord 𝐴) | |
17 | 15, 16 | syl6com 37 | . . . 4 ⊢ (𝑥 ∈ On → (𝐴 = suc 𝑥 → Ord 𝐴)) |
18 | 17 | rexlimiv 3145 | . . 3 ⊢ (∃𝑥 ∈ On 𝐴 = suc 𝑥 → Ord 𝐴) |
19 | limord 6429 | . . 3 ⊢ (Lim 𝐴 → Ord 𝐴) | |
20 | 12, 18, 19 | 3jaoi 1425 | . 2 ⊢ ((𝐴 = ∅ ∨ ∃𝑥 ∈ On 𝐴 = suc 𝑥 ∨ Lim 𝐴) → Ord 𝐴) |
21 | 9, 20 | impbii 208 | 1 ⊢ (Ord 𝐴 ↔ (𝐴 = ∅ ∨ ∃𝑥 ∈ On 𝐴 = suc 𝑥 ∨ Lim 𝐴)) |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 ↔ wb 205 ∨ wo 846 ∨ w3o 1084 = wceq 1534 ∈ wcel 2099 ∃wrex 3067 ∅c0 4323 ∪ cuni 4908 Ord word 6368 Oncon0 6369 Lim wlim 6370 suc csuc 6371 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1790 ax-4 1804 ax-5 1906 ax-6 1964 ax-7 2004 ax-8 2101 ax-9 2109 ax-11 2147 ax-ext 2699 ax-sep 5299 ax-nul 5306 ax-pr 5429 ax-un 7740 |
This theorem depends on definitions: df-bi 206 df-an 396 df-or 847 df-3or 1086 df-3an 1087 df-tru 1537 df-fal 1547 df-ex 1775 df-sb 2061 df-clab 2706 df-cleq 2720 df-clel 2806 df-ne 2938 df-ral 3059 df-rex 3068 df-rab 3430 df-v 3473 df-dif 3950 df-un 3952 df-in 3954 df-ss 3964 df-pss 3966 df-nul 4324 df-if 4530 df-pw 4605 df-sn 4630 df-pr 4632 df-op 4636 df-uni 4909 df-br 5149 df-opab 5211 df-tr 5266 df-eprel 5582 df-po 5590 df-so 5591 df-fr 5633 df-we 5635 df-ord 6372 df-on 6373 df-lim 6374 df-suc 6375 |
This theorem is referenced by: onzsl 7850 tfrlem16 8414 omeulem1 8603 oaabs2 8670 rankxplim3 9905 rankxpsuc 9906 cardlim 9996 cardaleph 10113 cflim2 10287 dfrdg2 35391 |
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