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Mirrors > Home > MPE Home > Th. List > orduniorsuc | Structured version Visualization version GIF version |
Description: An ordinal class is either its union or the successor of its union. If we adopt the view that zero is a limit ordinal, this means every ordinal class is either a limit or a successor. (Contributed by NM, 13-Sep-2003.) |
Ref | Expression |
---|---|
orduniorsuc | ⊢ (Ord 𝐴 → (𝐴 = ∪ 𝐴 ∨ 𝐴 = suc ∪ 𝐴)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | orduniss 6419 | . . . . . 6 ⊢ (Ord 𝐴 → ∪ 𝐴 ⊆ 𝐴) | |
2 | orduni 7729 | . . . . . . . 8 ⊢ (Ord 𝐴 → Ord ∪ 𝐴) | |
3 | ordelssne 6349 | . . . . . . . 8 ⊢ ((Ord ∪ 𝐴 ∧ Ord 𝐴) → (∪ 𝐴 ∈ 𝐴 ↔ (∪ 𝐴 ⊆ 𝐴 ∧ ∪ 𝐴 ≠ 𝐴))) | |
4 | 2, 3 | mpancom 687 | . . . . . . 7 ⊢ (Ord 𝐴 → (∪ 𝐴 ∈ 𝐴 ↔ (∪ 𝐴 ⊆ 𝐴 ∧ ∪ 𝐴 ≠ 𝐴))) |
5 | 4 | biimprd 248 | . . . . . 6 ⊢ (Ord 𝐴 → ((∪ 𝐴 ⊆ 𝐴 ∧ ∪ 𝐴 ≠ 𝐴) → ∪ 𝐴 ∈ 𝐴)) |
6 | 1, 5 | mpand 694 | . . . . 5 ⊢ (Ord 𝐴 → (∪ 𝐴 ≠ 𝐴 → ∪ 𝐴 ∈ 𝐴)) |
7 | ordsucss 7758 | . . . . 5 ⊢ (Ord 𝐴 → (∪ 𝐴 ∈ 𝐴 → suc ∪ 𝐴 ⊆ 𝐴)) | |
8 | 6, 7 | syld 47 | . . . 4 ⊢ (Ord 𝐴 → (∪ 𝐴 ≠ 𝐴 → suc ∪ 𝐴 ⊆ 𝐴)) |
9 | ordsucuni 7769 | . . . 4 ⊢ (Ord 𝐴 → 𝐴 ⊆ suc ∪ 𝐴) | |
10 | 8, 9 | jctild 527 | . . 3 ⊢ (Ord 𝐴 → (∪ 𝐴 ≠ 𝐴 → (𝐴 ⊆ suc ∪ 𝐴 ∧ suc ∪ 𝐴 ⊆ 𝐴))) |
11 | df-ne 2945 | . . . 4 ⊢ (𝐴 ≠ ∪ 𝐴 ↔ ¬ 𝐴 = ∪ 𝐴) | |
12 | necom 2998 | . . . 4 ⊢ (𝐴 ≠ ∪ 𝐴 ↔ ∪ 𝐴 ≠ 𝐴) | |
13 | 11, 12 | bitr3i 277 | . . 3 ⊢ (¬ 𝐴 = ∪ 𝐴 ↔ ∪ 𝐴 ≠ 𝐴) |
14 | eqss 3964 | . . 3 ⊢ (𝐴 = suc ∪ 𝐴 ↔ (𝐴 ⊆ suc ∪ 𝐴 ∧ suc ∪ 𝐴 ⊆ 𝐴)) | |
15 | 10, 13, 14 | 3imtr4g 296 | . 2 ⊢ (Ord 𝐴 → (¬ 𝐴 = ∪ 𝐴 → 𝐴 = suc ∪ 𝐴)) |
16 | 15 | orrd 862 | 1 ⊢ (Ord 𝐴 → (𝐴 = ∪ 𝐴 ∨ 𝐴 = suc ∪ 𝐴)) |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 → wi 4 ↔ wb 205 ∧ wa 397 ∨ wo 846 = wceq 1542 ∈ wcel 2107 ≠ wne 2944 ⊆ wss 3915 ∪ cuni 4870 Ord word 6321 suc csuc 6324 |
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-ext 2708 ax-sep 5261 ax-nul 5268 ax-pr 5389 |
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-sb 2069 df-clab 2715 df-cleq 2729 df-clel 2815 df-ne 2945 df-ral 3066 df-rex 3075 df-rab 3411 df-v 3450 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-br 5111 df-opab 5173 df-tr 5228 df-eprel 5542 df-po 5550 df-so 5551 df-fr 5593 df-we 5595 df-ord 6325 df-on 6326 df-suc 6328 |
This theorem is referenced by: onuniorsuc 7777 oeeulem 8553 cantnfp1lem2 9622 cantnflem1 9632 cnfcom2lem 9644 dfac12lem1 10086 dfac12lem2 10087 ttukeylem3 10454 ttukeylem5 10456 ttukeylem6 10457 ordtoplem 34936 ordcmp 34948 onsucuni3 35867 aomclem5 41414 omlimcl2 41605 onov0suclim 41638 dflim5 41693 onsetreclem3 47226 |
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