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Theorem blbas 24158
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.)
Assertion
Ref Expression
blbas (𝐷 ∈ (∞Metβ€˜π‘‹) β†’ ran (ballβ€˜π·) ∈ TopBases)

Proof of Theorem blbas
Dummy variables π‘₯ π‘Ÿ 𝑏 𝑦 𝑧 are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 blin2 24157 . . . . . 6 (((𝐷 ∈ (∞Metβ€˜π‘‹) ∧ 𝑧 ∈ (π‘₯ ∩ 𝑦)) ∧ (π‘₯ ∈ ran (ballβ€˜π·) ∧ 𝑦 ∈ ran (ballβ€˜π·))) β†’ βˆƒπ‘Ÿ ∈ ℝ+ (𝑧(ballβ€˜π·)π‘Ÿ) βŠ† (π‘₯ ∩ 𝑦))
2 simpll 763 . . . . . . 7 (((𝐷 ∈ (∞Metβ€˜π‘‹) ∧ 𝑧 ∈ (π‘₯ ∩ 𝑦)) ∧ (π‘₯ ∈ ran (ballβ€˜π·) ∧ 𝑦 ∈ ran (ballβ€˜π·))) β†’ 𝐷 ∈ (∞Metβ€˜π‘‹))
3 elinel1 4196 . . . . . . . . . 10 (𝑧 ∈ (π‘₯ ∩ 𝑦) β†’ 𝑧 ∈ π‘₯)
4 elunii 4914 . . . . . . . . . 10 ((𝑧 ∈ π‘₯ ∧ π‘₯ ∈ ran (ballβ€˜π·)) β†’ 𝑧 ∈ βˆͺ ran (ballβ€˜π·))
53, 4sylan 578 . . . . . . . . 9 ((𝑧 ∈ (π‘₯ ∩ 𝑦) ∧ π‘₯ ∈ ran (ballβ€˜π·)) β†’ 𝑧 ∈ βˆͺ ran (ballβ€˜π·))
65ad2ant2lr 744 . . . . . . . 8 (((𝐷 ∈ (∞Metβ€˜π‘‹) ∧ 𝑧 ∈ (π‘₯ ∩ 𝑦)) ∧ (π‘₯ ∈ ran (ballβ€˜π·) ∧ 𝑦 ∈ ran (ballβ€˜π·))) β†’ 𝑧 ∈ βˆͺ ran (ballβ€˜π·))
7 unirnbl 24148 . . . . . . . . 9 (𝐷 ∈ (∞Metβ€˜π‘‹) β†’ βˆͺ ran (ballβ€˜π·) = 𝑋)
87ad2antrr 722 . . . . . . . 8 (((𝐷 ∈ (∞Metβ€˜π‘‹) ∧ 𝑧 ∈ (π‘₯ ∩ 𝑦)) ∧ (π‘₯ ∈ ran (ballβ€˜π·) ∧ 𝑦 ∈ ran (ballβ€˜π·))) β†’ βˆͺ ran (ballβ€˜π·) = 𝑋)
96, 8eleqtrd 2833 . . . . . . 7 (((𝐷 ∈ (∞Metβ€˜π‘‹) ∧ 𝑧 ∈ (π‘₯ ∩ 𝑦)) ∧ (π‘₯ ∈ ran (ballβ€˜π·) ∧ 𝑦 ∈ ran (ballβ€˜π·))) β†’ 𝑧 ∈ 𝑋)
10 blssex 24155 . . . . . . 7 ((𝐷 ∈ (∞Metβ€˜π‘‹) ∧ 𝑧 ∈ 𝑋) β†’ (βˆƒπ‘ ∈ ran (ballβ€˜π·)(𝑧 ∈ 𝑏 ∧ 𝑏 βŠ† (π‘₯ ∩ 𝑦)) ↔ βˆƒπ‘Ÿ ∈ ℝ+ (𝑧(ballβ€˜π·)π‘Ÿ) βŠ† (π‘₯ ∩ 𝑦)))
112, 9, 10syl2anc 582 . . . . . 6 (((𝐷 ∈ (∞Metβ€˜π‘‹) ∧ 𝑧 ∈ (π‘₯ ∩ 𝑦)) ∧ (π‘₯ ∈ ran (ballβ€˜π·) ∧ 𝑦 ∈ ran (ballβ€˜π·))) β†’ (βˆƒπ‘ ∈ ran (ballβ€˜π·)(𝑧 ∈ 𝑏 ∧ 𝑏 βŠ† (π‘₯ ∩ 𝑦)) ↔ βˆƒπ‘Ÿ ∈ ℝ+ (𝑧(ballβ€˜π·)π‘Ÿ) βŠ† (π‘₯ ∩ 𝑦)))
121, 11mpbird 256 . . . . 5 (((𝐷 ∈ (∞Metβ€˜π‘‹) ∧ 𝑧 ∈ (π‘₯ ∩ 𝑦)) ∧ (π‘₯ ∈ ran (ballβ€˜π·) ∧ 𝑦 ∈ ran (ballβ€˜π·))) β†’ βˆƒπ‘ ∈ ran (ballβ€˜π·)(𝑧 ∈ 𝑏 ∧ 𝑏 βŠ† (π‘₯ ∩ 𝑦)))
1312ex 411 . . . 4 ((𝐷 ∈ (∞Metβ€˜π‘‹) ∧ 𝑧 ∈ (π‘₯ ∩ 𝑦)) β†’ ((π‘₯ ∈ ran (ballβ€˜π·) ∧ 𝑦 ∈ ran (ballβ€˜π·)) β†’ βˆƒπ‘ ∈ ran (ballβ€˜π·)(𝑧 ∈ 𝑏 ∧ 𝑏 βŠ† (π‘₯ ∩ 𝑦))))
1413ralrimdva 3152 . . 3 (𝐷 ∈ (∞Metβ€˜π‘‹) β†’ ((π‘₯ ∈ ran (ballβ€˜π·) ∧ 𝑦 ∈ ran (ballβ€˜π·)) β†’ βˆ€π‘§ ∈ (π‘₯ ∩ 𝑦)βˆƒπ‘ ∈ ran (ballβ€˜π·)(𝑧 ∈ 𝑏 ∧ 𝑏 βŠ† (π‘₯ ∩ 𝑦))))
1514ralrimivv 3196 . 2 (𝐷 ∈ (∞Metβ€˜π‘‹) β†’ βˆ€π‘₯ ∈ ran (ballβ€˜π·)βˆ€π‘¦ ∈ ran (ballβ€˜π·)βˆ€π‘§ ∈ (π‘₯ ∩ 𝑦)βˆƒπ‘ ∈ ran (ballβ€˜π·)(𝑧 ∈ 𝑏 ∧ 𝑏 βŠ† (π‘₯ ∩ 𝑦)))
16 fvex 6905 . . . 4 (ballβ€˜π·) ∈ V
1716rnex 7907 . . 3 ran (ballβ€˜π·) ∈ V
18 isbasis2g 22673 . . 3 (ran (ballβ€˜π·) ∈ V β†’ (ran (ballβ€˜π·) ∈ TopBases ↔ βˆ€π‘₯ ∈ ran (ballβ€˜π·)βˆ€π‘¦ ∈ ran (ballβ€˜π·)βˆ€π‘§ ∈ (π‘₯ ∩ 𝑦)βˆƒπ‘ ∈ ran (ballβ€˜π·)(𝑧 ∈ 𝑏 ∧ 𝑏 βŠ† (π‘₯ ∩ 𝑦))))
1917, 18ax-mp 5 . 2 (ran (ballβ€˜π·) ∈ TopBases ↔ βˆ€π‘₯ ∈ ran (ballβ€˜π·)βˆ€π‘¦ ∈ ran (ballβ€˜π·)βˆ€π‘§ ∈ (π‘₯ ∩ 𝑦)βˆƒπ‘ ∈ ran (ballβ€˜π·)(𝑧 ∈ 𝑏 ∧ 𝑏 βŠ† (π‘₯ ∩ 𝑦)))
2015, 19sylibr 233 1 (𝐷 ∈ (∞Metβ€˜π‘‹) β†’ ran (ballβ€˜π·) ∈ TopBases)
Colors of variables: wff setvar class
Syntax hints:   β†’ wi 4   ↔ wb 205   ∧ wa 394   = wceq 1539   ∈ wcel 2104  βˆ€wral 3059  βˆƒwrex 3068  Vcvv 3472   ∩ cin 3948   βŠ† wss 3949  βˆͺ cuni 4909  ran crn 5678  β€˜cfv 6544  (class class class)co 7413  β„+crp 12980  βˆžMetcxmet 21131  ballcbl 21133  TopBasesctb 22670
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1795  ax-4 1809  ax-5 1911  ax-6 1969  ax-7 2009  ax-8 2106  ax-9 2114  ax-10 2135  ax-11 2152  ax-12 2169  ax-ext 2701  ax-sep 5300  ax-nul 5307  ax-pow 5364  ax-pr 5428  ax-un 7729  ax-cnex 11170  ax-resscn 11171  ax-1cn 11172  ax-icn 11173  ax-addcl 11174  ax-addrcl 11175  ax-mulcl 11176  ax-mulrcl 11177  ax-mulcom 11178  ax-addass 11179  ax-mulass 11180  ax-distr 11181  ax-i2m1 11182  ax-1ne0 11183  ax-1rid 11184  ax-rnegex 11185  ax-rrecex 11186  ax-cnre 11187  ax-pre-lttri 11188  ax-pre-lttrn 11189  ax-pre-ltadd 11190  ax-pre-mulgt0 11191  ax-pre-sup 11192
This theorem depends on definitions:  df-bi 206  df-an 395  df-or 844  df-3or 1086  df-3an 1087  df-tru 1542  df-fal 1552  df-ex 1780  df-nf 1784  df-sb 2066  df-mo 2532  df-eu 2561  df-clab 2708  df-cleq 2722  df-clel 2808  df-nfc 2883  df-ne 2939  df-nel 3045  df-ral 3060  df-rex 3069  df-rmo 3374  df-reu 3375  df-rab 3431  df-v 3474  df-sbc 3779  df-csb 3895  df-dif 3952  df-un 3954  df-in 3956  df-ss 3966  df-pss 3968  df-nul 4324  df-if 4530  df-pw 4605  df-sn 4630  df-pr 4632  df-op 4636  df-uni 4910  df-iun 5000  df-br 5150  df-opab 5212  df-mpt 5233  df-tr 5267  df-id 5575  df-eprel 5581  df-po 5589  df-so 5590  df-fr 5632  df-we 5634  df-xp 5683  df-rel 5684  df-cnv 5685  df-co 5686  df-dm 5687  df-rn 5688  df-res 5689  df-ima 5690  df-pred 6301  df-ord 6368  df-on 6369  df-lim 6370  df-suc 6371  df-iota 6496  df-fun 6546  df-fn 6547  df-f 6548  df-f1 6549  df-fo 6550  df-f1o 6551  df-fv 6552  df-riota 7369  df-ov 7416  df-oprab 7417  df-mpo 7418  df-om 7860  df-1st 7979  df-2nd 7980  df-frecs 8270  df-wrecs 8301  df-recs 8375  df-rdg 8414  df-er 8707  df-map 8826  df-en 8944  df-dom 8945  df-sdom 8946  df-sup 9441  df-inf 9442  df-pnf 11256  df-mnf 11257  df-xr 11258  df-ltxr 11259  df-le 11260  df-sub 11452  df-neg 11453  df-div 11878  df-nn 12219  df-2 12281  df-n0 12479  df-z 12565  df-uz 12829  df-q 12939  df-rp 12981  df-xneg 13098  df-xadd 13099  df-xmul 13100  df-psmet 21138  df-xmet 21139  df-bl 21141  df-bases 22671
This theorem is referenced by:  mopntopon  24167  elmopn  24170  imasf1oxms  24220  blssopn  24226  metss  24239
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