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Mirrors > Home > MPE Home > Th. List > cmphmph | Structured version Visualization version GIF version |
Description: Compactness is a topological property-that is, for any two homeomorphic topologies, either both are compact or neither is. (Contributed by Jeff Hankins, 30-Jun-2009.) (Revised by Mario Carneiro, 23-Aug-2015.) |
Ref | Expression |
---|---|
cmphmph | ⊢ (𝐽 ≃ 𝐾 → (𝐽 ∈ Comp → 𝐾 ∈ Comp)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | hmph 23271 | . 2 ⊢ (𝐽 ≃ 𝐾 ↔ (𝐽Homeo𝐾) ≠ ∅) | |
2 | n0 4345 | . . 3 ⊢ ((𝐽Homeo𝐾) ≠ ∅ ↔ ∃𝑓 𝑓 ∈ (𝐽Homeo𝐾)) | |
3 | eqid 2732 | . . . . . . 7 ⊢ ∪ 𝐽 = ∪ 𝐽 | |
4 | eqid 2732 | . . . . . . 7 ⊢ ∪ 𝐾 = ∪ 𝐾 | |
5 | 3, 4 | hmeof1o 23259 | . . . . . 6 ⊢ (𝑓 ∈ (𝐽Homeo𝐾) → 𝑓:∪ 𝐽–1-1-onto→∪ 𝐾) |
6 | f1ofo 6837 | . . . . . 6 ⊢ (𝑓:∪ 𝐽–1-1-onto→∪ 𝐾 → 𝑓:∪ 𝐽–onto→∪ 𝐾) | |
7 | 5, 6 | syl 17 | . . . . 5 ⊢ (𝑓 ∈ (𝐽Homeo𝐾) → 𝑓:∪ 𝐽–onto→∪ 𝐾) |
8 | hmeocn 23255 | . . . . 5 ⊢ (𝑓 ∈ (𝐽Homeo𝐾) → 𝑓 ∈ (𝐽 Cn 𝐾)) | |
9 | 4 | cncmp 22887 | . . . . . . 7 ⊢ ((𝐽 ∈ Comp ∧ 𝑓:∪ 𝐽–onto→∪ 𝐾 ∧ 𝑓 ∈ (𝐽 Cn 𝐾)) → 𝐾 ∈ Comp) |
10 | 9 | 3expb 1120 | . . . . . 6 ⊢ ((𝐽 ∈ Comp ∧ (𝑓:∪ 𝐽–onto→∪ 𝐾 ∧ 𝑓 ∈ (𝐽 Cn 𝐾))) → 𝐾 ∈ Comp) |
11 | 10 | expcom 414 | . . . . 5 ⊢ ((𝑓:∪ 𝐽–onto→∪ 𝐾 ∧ 𝑓 ∈ (𝐽 Cn 𝐾)) → (𝐽 ∈ Comp → 𝐾 ∈ Comp)) |
12 | 7, 8, 11 | syl2anc 584 | . . . 4 ⊢ (𝑓 ∈ (𝐽Homeo𝐾) → (𝐽 ∈ Comp → 𝐾 ∈ Comp)) |
13 | 12 | exlimiv 1933 | . . 3 ⊢ (∃𝑓 𝑓 ∈ (𝐽Homeo𝐾) → (𝐽 ∈ Comp → 𝐾 ∈ Comp)) |
14 | 2, 13 | sylbi 216 | . 2 ⊢ ((𝐽Homeo𝐾) ≠ ∅ → (𝐽 ∈ Comp → 𝐾 ∈ Comp)) |
15 | 1, 14 | sylbi 216 | 1 ⊢ (𝐽 ≃ 𝐾 → (𝐽 ∈ Comp → 𝐾 ∈ Comp)) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 396 ∃wex 1781 ∈ wcel 2106 ≠ wne 2940 ∅c0 4321 ∪ cuni 4907 class class class wbr 5147 –onto→wfo 6538 –1-1-onto→wf1o 6539 (class class class)co 7405 Cn ccn 22719 Compccmp 22881 Homeochmeo 23248 ≃ chmph 23249 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1797 ax-4 1811 ax-5 1913 ax-6 1971 ax-7 2011 ax-8 2108 ax-9 2116 ax-10 2137 ax-11 2154 ax-12 2171 ax-ext 2703 ax-sep 5298 ax-nul 5305 ax-pow 5362 ax-pr 5426 ax-un 7721 |
This theorem depends on definitions: df-bi 206 df-an 397 df-or 846 df-3or 1088 df-3an 1089 df-tru 1544 df-fal 1554 df-ex 1782 df-nf 1786 df-sb 2068 df-mo 2534 df-eu 2563 df-clab 2710 df-cleq 2724 df-clel 2810 df-nfc 2885 df-ne 2941 df-ral 3062 df-rex 3071 df-reu 3377 df-rab 3433 df-v 3476 df-sbc 3777 df-csb 3893 df-dif 3950 df-un 3952 df-in 3954 df-ss 3964 df-pss 3966 df-nul 4322 df-if 4528 df-pw 4603 df-sn 4628 df-pr 4630 df-op 4634 df-uni 4908 df-iun 4998 df-br 5148 df-opab 5210 df-mpt 5231 df-tr 5265 df-id 5573 df-eprel 5579 df-po 5587 df-so 5588 df-fr 5630 df-we 5632 df-xp 5681 df-rel 5682 df-cnv 5683 df-co 5684 df-dm 5685 df-rn 5686 df-res 5687 df-ima 5688 df-ord 6364 df-on 6365 df-lim 6366 df-suc 6367 df-iota 6492 df-fun 6542 df-fn 6543 df-f 6544 df-f1 6545 df-fo 6546 df-f1o 6547 df-fv 6548 df-ov 7408 df-oprab 7409 df-mpo 7410 df-om 7852 df-1st 7971 df-2nd 7972 df-1o 8462 df-er 8699 df-map 8818 df-en 8936 df-dom 8937 df-fin 8939 df-top 22387 df-topon 22404 df-cn 22722 df-cmp 22882 df-hmeo 23250 df-hmph 23251 |
This theorem is referenced by: ptcmpfi 23308 xrcmp 24455 reheibor 36695 |
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