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Mirrors > Home > MPE Home > Th. List > blbas | Structured version Visualization version GIF version |
Description: The balls of a metric space form a basis for a topology. (Contributed by NM, 12-Sep-2006.) (Revised by Mario Carneiro, 15-Jan-2014.) |
Ref | Expression |
---|---|
blbas | ⊢ (𝐷 ∈ (∞Met‘𝑋) → ran (ball‘𝐷) ∈ TopBases) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | blin2 23591 | . . . . . 6 ⊢ (((𝐷 ∈ (∞Met‘𝑋) ∧ 𝑧 ∈ (𝑥 ∩ 𝑦)) ∧ (𝑥 ∈ ran (ball‘𝐷) ∧ 𝑦 ∈ ran (ball‘𝐷))) → ∃𝑟 ∈ ℝ+ (𝑧(ball‘𝐷)𝑟) ⊆ (𝑥 ∩ 𝑦)) | |
2 | simpll 764 | . . . . . . 7 ⊢ (((𝐷 ∈ (∞Met‘𝑋) ∧ 𝑧 ∈ (𝑥 ∩ 𝑦)) ∧ (𝑥 ∈ ran (ball‘𝐷) ∧ 𝑦 ∈ ran (ball‘𝐷))) → 𝐷 ∈ (∞Met‘𝑋)) | |
3 | elinel1 4130 | . . . . . . . . . 10 ⊢ (𝑧 ∈ (𝑥 ∩ 𝑦) → 𝑧 ∈ 𝑥) | |
4 | elunii 4845 | . . . . . . . . . 10 ⊢ ((𝑧 ∈ 𝑥 ∧ 𝑥 ∈ ran (ball‘𝐷)) → 𝑧 ∈ ∪ ran (ball‘𝐷)) | |
5 | 3, 4 | sylan 580 | . . . . . . . . 9 ⊢ ((𝑧 ∈ (𝑥 ∩ 𝑦) ∧ 𝑥 ∈ ran (ball‘𝐷)) → 𝑧 ∈ ∪ ran (ball‘𝐷)) |
6 | 5 | ad2ant2lr 745 | . . . . . . . 8 ⊢ (((𝐷 ∈ (∞Met‘𝑋) ∧ 𝑧 ∈ (𝑥 ∩ 𝑦)) ∧ (𝑥 ∈ ran (ball‘𝐷) ∧ 𝑦 ∈ ran (ball‘𝐷))) → 𝑧 ∈ ∪ ran (ball‘𝐷)) |
7 | unirnbl 23582 | . . . . . . . . 9 ⊢ (𝐷 ∈ (∞Met‘𝑋) → ∪ ran (ball‘𝐷) = 𝑋) | |
8 | 7 | ad2antrr 723 | . . . . . . . 8 ⊢ (((𝐷 ∈ (∞Met‘𝑋) ∧ 𝑧 ∈ (𝑥 ∩ 𝑦)) ∧ (𝑥 ∈ ran (ball‘𝐷) ∧ 𝑦 ∈ ran (ball‘𝐷))) → ∪ ran (ball‘𝐷) = 𝑋) |
9 | 6, 8 | eleqtrd 2842 | . . . . . . 7 ⊢ (((𝐷 ∈ (∞Met‘𝑋) ∧ 𝑧 ∈ (𝑥 ∩ 𝑦)) ∧ (𝑥 ∈ ran (ball‘𝐷) ∧ 𝑦 ∈ ran (ball‘𝐷))) → 𝑧 ∈ 𝑋) |
10 | blssex 23589 | . . . . . . 7 ⊢ ((𝐷 ∈ (∞Met‘𝑋) ∧ 𝑧 ∈ 𝑋) → (∃𝑏 ∈ ran (ball‘𝐷)(𝑧 ∈ 𝑏 ∧ 𝑏 ⊆ (𝑥 ∩ 𝑦)) ↔ ∃𝑟 ∈ ℝ+ (𝑧(ball‘𝐷)𝑟) ⊆ (𝑥 ∩ 𝑦))) | |
11 | 2, 9, 10 | syl2anc 584 | . . . . . 6 ⊢ (((𝐷 ∈ (∞Met‘𝑋) ∧ 𝑧 ∈ (𝑥 ∩ 𝑦)) ∧ (𝑥 ∈ ran (ball‘𝐷) ∧ 𝑦 ∈ ran (ball‘𝐷))) → (∃𝑏 ∈ ran (ball‘𝐷)(𝑧 ∈ 𝑏 ∧ 𝑏 ⊆ (𝑥 ∩ 𝑦)) ↔ ∃𝑟 ∈ ℝ+ (𝑧(ball‘𝐷)𝑟) ⊆ (𝑥 ∩ 𝑦))) |
12 | 1, 11 | mpbird 256 | . . . . 5 ⊢ (((𝐷 ∈ (∞Met‘𝑋) ∧ 𝑧 ∈ (𝑥 ∩ 𝑦)) ∧ (𝑥 ∈ ran (ball‘𝐷) ∧ 𝑦 ∈ ran (ball‘𝐷))) → ∃𝑏 ∈ ran (ball‘𝐷)(𝑧 ∈ 𝑏 ∧ 𝑏 ⊆ (𝑥 ∩ 𝑦))) |
13 | 12 | ex 413 | . . . 4 ⊢ ((𝐷 ∈ (∞Met‘𝑋) ∧ 𝑧 ∈ (𝑥 ∩ 𝑦)) → ((𝑥 ∈ ran (ball‘𝐷) ∧ 𝑦 ∈ ran (ball‘𝐷)) → ∃𝑏 ∈ ran (ball‘𝐷)(𝑧 ∈ 𝑏 ∧ 𝑏 ⊆ (𝑥 ∩ 𝑦)))) |
14 | 13 | ralrimdva 3107 | . . 3 ⊢ (𝐷 ∈ (∞Met‘𝑋) → ((𝑥 ∈ ran (ball‘𝐷) ∧ 𝑦 ∈ ran (ball‘𝐷)) → ∀𝑧 ∈ (𝑥 ∩ 𝑦)∃𝑏 ∈ ran (ball‘𝐷)(𝑧 ∈ 𝑏 ∧ 𝑏 ⊆ (𝑥 ∩ 𝑦)))) |
15 | 14 | ralrimivv 3123 | . 2 ⊢ (𝐷 ∈ (∞Met‘𝑋) → ∀𝑥 ∈ ran (ball‘𝐷)∀𝑦 ∈ ran (ball‘𝐷)∀𝑧 ∈ (𝑥 ∩ 𝑦)∃𝑏 ∈ ran (ball‘𝐷)(𝑧 ∈ 𝑏 ∧ 𝑏 ⊆ (𝑥 ∩ 𝑦))) |
16 | fvex 6796 | . . . 4 ⊢ (ball‘𝐷) ∈ V | |
17 | 16 | rnex 7768 | . . 3 ⊢ ran (ball‘𝐷) ∈ V |
18 | isbasis2g 22107 | . . 3 ⊢ (ran (ball‘𝐷) ∈ V → (ran (ball‘𝐷) ∈ TopBases ↔ ∀𝑥 ∈ ran (ball‘𝐷)∀𝑦 ∈ ran (ball‘𝐷)∀𝑧 ∈ (𝑥 ∩ 𝑦)∃𝑏 ∈ ran (ball‘𝐷)(𝑧 ∈ 𝑏 ∧ 𝑏 ⊆ (𝑥 ∩ 𝑦)))) | |
19 | 17, 18 | ax-mp 5 | . 2 ⊢ (ran (ball‘𝐷) ∈ TopBases ↔ ∀𝑥 ∈ ran (ball‘𝐷)∀𝑦 ∈ ran (ball‘𝐷)∀𝑧 ∈ (𝑥 ∩ 𝑦)∃𝑏 ∈ ran (ball‘𝐷)(𝑧 ∈ 𝑏 ∧ 𝑏 ⊆ (𝑥 ∩ 𝑦))) |
20 | 15, 19 | sylibr 233 | 1 ⊢ (𝐷 ∈ (∞Met‘𝑋) → ran (ball‘𝐷) ∈ TopBases) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ↔ wb 205 ∧ wa 396 = wceq 1539 ∈ wcel 2107 ∀wral 3065 ∃wrex 3066 Vcvv 3433 ∩ cin 3887 ⊆ wss 3888 ∪ cuni 4840 ran crn 5591 ‘cfv 6437 (class class class)co 7284 ℝ+crp 12739 ∞Metcxmet 20591 ballcbl 20593 TopBasesctb 22104 |
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-10 2138 ax-11 2155 ax-12 2172 ax-ext 2710 ax-sep 5224 ax-nul 5231 ax-pow 5289 ax-pr 5353 ax-un 7597 ax-cnex 10936 ax-resscn 10937 ax-1cn 10938 ax-icn 10939 ax-addcl 10940 ax-addrcl 10941 ax-mulcl 10942 ax-mulrcl 10943 ax-mulcom 10944 ax-addass 10945 ax-mulass 10946 ax-distr 10947 ax-i2m1 10948 ax-1ne0 10949 ax-1rid 10950 ax-rnegex 10951 ax-rrecex 10952 ax-cnre 10953 ax-pre-lttri 10954 ax-pre-lttrn 10955 ax-pre-ltadd 10956 ax-pre-mulgt0 10957 ax-pre-sup 10958 |
This theorem depends on definitions: df-bi 206 df-an 397 df-or 845 df-3or 1087 df-3an 1088 df-tru 1542 df-fal 1552 df-ex 1783 df-nf 1787 df-sb 2069 df-mo 2541 df-eu 2570 df-clab 2717 df-cleq 2731 df-clel 2817 df-nfc 2890 df-ne 2945 df-nel 3051 df-ral 3070 df-rex 3071 df-rmo 3072 df-reu 3073 df-rab 3074 df-v 3435 df-sbc 3718 df-csb 3834 df-dif 3891 df-un 3893 df-in 3895 df-ss 3905 df-pss 3907 df-nul 4258 df-if 4461 df-pw 4536 df-sn 4563 df-pr 4565 df-op 4569 df-uni 4841 df-iun 4927 df-br 5076 df-opab 5138 df-mpt 5159 df-tr 5193 df-id 5490 df-eprel 5496 df-po 5504 df-so 5505 df-fr 5545 df-we 5547 df-xp 5596 df-rel 5597 df-cnv 5598 df-co 5599 df-dm 5600 df-rn 5601 df-res 5602 df-ima 5603 df-pred 6206 df-ord 6273 df-on 6274 df-lim 6275 df-suc 6276 df-iota 6395 df-fun 6439 df-fn 6440 df-f 6441 df-f1 6442 df-fo 6443 df-f1o 6444 df-fv 6445 df-riota 7241 df-ov 7287 df-oprab 7288 df-mpo 7289 df-om 7722 df-1st 7840 df-2nd 7841 df-frecs 8106 df-wrecs 8137 df-recs 8211 df-rdg 8250 df-er 8507 df-map 8626 df-en 8743 df-dom 8744 df-sdom 8745 df-sup 9210 df-inf 9211 df-pnf 11020 df-mnf 11021 df-xr 11022 df-ltxr 11023 df-le 11024 df-sub 11216 df-neg 11217 df-div 11642 df-nn 11983 df-2 12045 df-n0 12243 df-z 12329 df-uz 12592 df-q 12698 df-rp 12740 df-xneg 12857 df-xadd 12858 df-xmul 12859 df-psmet 20598 df-xmet 20599 df-bl 20601 df-bases 22105 |
This theorem is referenced by: mopntopon 23601 elmopn 23604 imasf1oxms 23654 blssopn 23660 metss 23673 |
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