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Mirrors > Home > MPE Home > Th. List > Mathboxes > ontopbas | Structured version Visualization version GIF version |
Description: An ordinal number is a topological basis. (Contributed by Chen-Pang He, 8-Oct-2015.) |
Ref | Expression |
---|---|
ontopbas | ⊢ (𝐵 ∈ On → 𝐵 ∈ TopBases) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | onelon 6001 | . . . . . . . 8 ⊢ ((𝐵 ∈ On ∧ 𝑥 ∈ 𝐵) → 𝑥 ∈ On) | |
2 | onelon 6001 | . . . . . . . 8 ⊢ ((𝐵 ∈ On ∧ 𝑦 ∈ 𝐵) → 𝑦 ∈ On) | |
3 | 1, 2 | anim12dan 612 | . . . . . . 7 ⊢ ((𝐵 ∈ On ∧ (𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵)) → (𝑥 ∈ On ∧ 𝑦 ∈ On)) |
4 | 3 | ex 403 | . . . . . 6 ⊢ (𝐵 ∈ On → ((𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵) → (𝑥 ∈ On ∧ 𝑦 ∈ On))) |
5 | onin 6007 | . . . . . 6 ⊢ ((𝑥 ∈ On ∧ 𝑦 ∈ On) → (𝑥 ∩ 𝑦) ∈ On) | |
6 | 4, 5 | syl6 35 | . . . . 5 ⊢ (𝐵 ∈ On → ((𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵) → (𝑥 ∩ 𝑦) ∈ On)) |
7 | 6 | anc2ri 552 | . . . 4 ⊢ (𝐵 ∈ On → ((𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵) → ((𝑥 ∩ 𝑦) ∈ On ∧ 𝐵 ∈ On))) |
8 | inss1 4053 | . . . . . . 7 ⊢ (𝑥 ∩ 𝑦) ⊆ 𝑥 | |
9 | 8 | jctl 519 | . . . . . 6 ⊢ (𝑥 ∈ 𝐵 → ((𝑥 ∩ 𝑦) ⊆ 𝑥 ∧ 𝑥 ∈ 𝐵)) |
10 | 9 | adantr 474 | . . . . 5 ⊢ ((𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵) → ((𝑥 ∩ 𝑦) ⊆ 𝑥 ∧ 𝑥 ∈ 𝐵)) |
11 | 10 | a1i 11 | . . . 4 ⊢ (𝐵 ∈ On → ((𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵) → ((𝑥 ∩ 𝑦) ⊆ 𝑥 ∧ 𝑥 ∈ 𝐵))) |
12 | ontr2 6023 | . . . 4 ⊢ (((𝑥 ∩ 𝑦) ∈ On ∧ 𝐵 ∈ On) → (((𝑥 ∩ 𝑦) ⊆ 𝑥 ∧ 𝑥 ∈ 𝐵) → (𝑥 ∩ 𝑦) ∈ 𝐵)) | |
13 | 7, 11, 12 | syl6c 70 | . . 3 ⊢ (𝐵 ∈ On → ((𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐵) → (𝑥 ∩ 𝑦) ∈ 𝐵)) |
14 | 13 | ralrimivv 3152 | . 2 ⊢ (𝐵 ∈ On → ∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥 ∩ 𝑦) ∈ 𝐵) |
15 | fiinbas 21164 | . 2 ⊢ ((𝐵 ∈ On ∧ ∀𝑥 ∈ 𝐵 ∀𝑦 ∈ 𝐵 (𝑥 ∩ 𝑦) ∈ 𝐵) → 𝐵 ∈ TopBases) | |
16 | 14, 15 | mpdan 677 | 1 ⊢ (𝐵 ∈ On → 𝐵 ∈ TopBases) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 386 ∈ wcel 2107 ∀wral 3090 ∩ cin 3791 ⊆ wss 3792 Oncon0 5976 TopBasesctb 21157 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1839 ax-4 1853 ax-5 1953 ax-6 2021 ax-7 2055 ax-9 2116 ax-10 2135 ax-11 2150 ax-12 2163 ax-13 2334 ax-ext 2754 ax-sep 5017 ax-nul 5025 ax-pr 5138 |
This theorem depends on definitions: df-bi 199 df-an 387 df-or 837 df-3or 1072 df-3an 1073 df-tru 1605 df-ex 1824 df-nf 1828 df-sb 2012 df-mo 2551 df-eu 2587 df-clab 2764 df-cleq 2770 df-clel 2774 df-nfc 2921 df-ne 2970 df-ral 3095 df-rex 3096 df-rab 3099 df-v 3400 df-sbc 3653 df-dif 3795 df-un 3797 df-in 3799 df-ss 3806 df-pss 3808 df-nul 4142 df-if 4308 df-pw 4381 df-sn 4399 df-pr 4401 df-op 4405 df-uni 4672 df-br 4887 df-opab 4949 df-tr 4988 df-eprel 5266 df-po 5274 df-so 5275 df-fr 5314 df-we 5316 df-ord 5979 df-on 5980 df-bases 21158 |
This theorem is referenced by: onsstopbas 33011 onsuctop 33015 |
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