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Mirrors > Home > MPE Home > Th. List > limom | Structured version Visualization version GIF version |
Description: Omega is a limit ordinal. Theorem 2.8 of [BellMachover] p. 473. Our proof, however, does not require the Axiom of Infinity. (Contributed by NM, 26-Mar-1995.) (Proof shortened by Mario Carneiro, 2-Sep-2015.) |
Ref | Expression |
---|---|
limom | ⊢ Lim ω |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ordom 7074 | . 2 ⊢ Ord ω | |
2 | ordeleqon 6988 | . . 3 ⊢ (Ord ω ↔ (ω ∈ On ∨ ω = On)) | |
3 | ordirr 5741 | . . . . . . 7 ⊢ (Ord ω → ¬ ω ∈ ω) | |
4 | 1, 3 | ax-mp 5 | . . . . . 6 ⊢ ¬ ω ∈ ω |
5 | elom 7068 | . . . . . . 7 ⊢ (ω ∈ ω ↔ (ω ∈ On ∧ ∀𝑥(Lim 𝑥 → ω ∈ 𝑥))) | |
6 | 5 | baib 944 | . . . . . 6 ⊢ (ω ∈ On → (ω ∈ ω ↔ ∀𝑥(Lim 𝑥 → ω ∈ 𝑥))) |
7 | 4, 6 | mtbii 316 | . . . . 5 ⊢ (ω ∈ On → ¬ ∀𝑥(Lim 𝑥 → ω ∈ 𝑥)) |
8 | limomss 7070 | . . . . . . . . . . 11 ⊢ (Lim 𝑥 → ω ⊆ 𝑥) | |
9 | limord 5784 | . . . . . . . . . . . 12 ⊢ (Lim 𝑥 → Ord 𝑥) | |
10 | ordsseleq 5752 | . . . . . . . . . . . 12 ⊢ ((Ord ω ∧ Ord 𝑥) → (ω ⊆ 𝑥 ↔ (ω ∈ 𝑥 ∨ ω = 𝑥))) | |
11 | 1, 9, 10 | sylancr 695 | . . . . . . . . . . 11 ⊢ (Lim 𝑥 → (ω ⊆ 𝑥 ↔ (ω ∈ 𝑥 ∨ ω = 𝑥))) |
12 | 8, 11 | mpbid 222 | . . . . . . . . . 10 ⊢ (Lim 𝑥 → (ω ∈ 𝑥 ∨ ω = 𝑥)) |
13 | 12 | ord 392 | . . . . . . . . 9 ⊢ (Lim 𝑥 → (¬ ω ∈ 𝑥 → ω = 𝑥)) |
14 | limeq 5735 | . . . . . . . . . 10 ⊢ (ω = 𝑥 → (Lim ω ↔ Lim 𝑥)) | |
15 | 14 | biimprcd 240 | . . . . . . . . 9 ⊢ (Lim 𝑥 → (ω = 𝑥 → Lim ω)) |
16 | 13, 15 | syld 47 | . . . . . . . 8 ⊢ (Lim 𝑥 → (¬ ω ∈ 𝑥 → Lim ω)) |
17 | 16 | con1d 139 | . . . . . . 7 ⊢ (Lim 𝑥 → (¬ Lim ω → ω ∈ 𝑥)) |
18 | 17 | com12 32 | . . . . . 6 ⊢ (¬ Lim ω → (Lim 𝑥 → ω ∈ 𝑥)) |
19 | 18 | alrimiv 1855 | . . . . 5 ⊢ (¬ Lim ω → ∀𝑥(Lim 𝑥 → ω ∈ 𝑥)) |
20 | 7, 19 | nsyl2 142 | . . . 4 ⊢ (ω ∈ On → Lim ω) |
21 | limon 7036 | . . . . 5 ⊢ Lim On | |
22 | limeq 5735 | . . . . 5 ⊢ (ω = On → (Lim ω ↔ Lim On)) | |
23 | 21, 22 | mpbiri 248 | . . . 4 ⊢ (ω = On → Lim ω) |
24 | 20, 23 | jaoi 394 | . . 3 ⊢ ((ω ∈ On ∨ ω = On) → Lim ω) |
25 | 2, 24 | sylbi 207 | . 2 ⊢ (Ord ω → Lim ω) |
26 | 1, 25 | ax-mp 5 | 1 ⊢ Lim ω |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 → wi 4 ↔ wb 196 ∨ wo 383 ∀wal 1481 = wceq 1483 ∈ wcel 1990 ⊆ wss 3574 Ord word 5722 Oncon0 5723 Lim wlim 5724 ωcom 7065 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1722 ax-4 1737 ax-5 1839 ax-6 1888 ax-7 1935 ax-8 1992 ax-9 1999 ax-10 2019 ax-11 2034 ax-12 2047 ax-13 2246 ax-ext 2602 ax-sep 4781 ax-nul 4789 ax-pr 4906 ax-un 6949 |
This theorem depends on definitions: df-bi 197 df-or 385 df-an 386 df-3or 1038 df-3an 1039 df-tru 1486 df-ex 1705 df-nf 1710 df-sb 1881 df-eu 2474 df-mo 2475 df-clab 2609 df-cleq 2615 df-clel 2618 df-nfc 2753 df-ne 2795 df-ral 2917 df-rex 2918 df-rab 2921 df-v 3202 df-sbc 3436 df-dif 3577 df-un 3579 df-in 3581 df-ss 3588 df-pss 3590 df-nul 3916 df-if 4087 df-pw 4160 df-sn 4178 df-pr 4180 df-tp 4182 df-op 4184 df-uni 4437 df-br 4654 df-opab 4713 df-tr 4753 df-eprel 5029 df-po 5035 df-so 5036 df-fr 5073 df-we 5075 df-ord 5726 df-on 5727 df-lim 5728 df-suc 5729 df-om 7066 |
This theorem is referenced by: peano2b 7081 ssnlim 7083 peano1 7085 onesuc 7610 oaabslem 7723 oaabs2 7725 omabslem 7726 infensuc 8138 infeq5i 8533 elom3 8545 omenps 8552 omensuc 8553 infdifsn 8554 cardlim 8798 r1om 9066 cfom 9086 ominf4 9134 alephom 9407 wunex3 9563 |
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