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Mirrors > Home > MPE Home > Th. List > xbln0 | Structured version Visualization version GIF version |
Description: A ball is nonempty iff the radius is positive. (Contributed by Mario Carneiro, 23-Aug-2015.) |
Ref | Expression |
---|---|
xbln0 | ⊢ ((𝐷 ∈ (∞Met‘𝑋) ∧ 𝑃 ∈ 𝑋 ∧ 𝑅 ∈ ℝ*) → ((𝑃(ball‘𝐷)𝑅) ≠ ∅ ↔ 0 < 𝑅)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | n0 4283 | . . 3 ⊢ ((𝑃(ball‘𝐷)𝑅) ≠ ∅ ↔ ∃𝑥 𝑥 ∈ (𝑃(ball‘𝐷)𝑅)) | |
2 | elbl 23569 | . . . . 5 ⊢ ((𝐷 ∈ (∞Met‘𝑋) ∧ 𝑃 ∈ 𝑋 ∧ 𝑅 ∈ ℝ*) → (𝑥 ∈ (𝑃(ball‘𝐷)𝑅) ↔ (𝑥 ∈ 𝑋 ∧ (𝑃𝐷𝑥) < 𝑅))) | |
3 | xmetge0 23525 | . . . . . . . . 9 ⊢ ((𝐷 ∈ (∞Met‘𝑋) ∧ 𝑃 ∈ 𝑋 ∧ 𝑥 ∈ 𝑋) → 0 ≤ (𝑃𝐷𝑥)) | |
4 | 3 | 3expa 1116 | . . . . . . . 8 ⊢ (((𝐷 ∈ (∞Met‘𝑋) ∧ 𝑃 ∈ 𝑋) ∧ 𝑥 ∈ 𝑋) → 0 ≤ (𝑃𝐷𝑥)) |
5 | 4 | 3adantl3 1166 | . . . . . . 7 ⊢ (((𝐷 ∈ (∞Met‘𝑋) ∧ 𝑃 ∈ 𝑋 ∧ 𝑅 ∈ ℝ*) ∧ 𝑥 ∈ 𝑋) → 0 ≤ (𝑃𝐷𝑥)) |
6 | 0xr 11050 | . . . . . . . 8 ⊢ 0 ∈ ℝ* | |
7 | xmetcl 23512 | . . . . . . . . . 10 ⊢ ((𝐷 ∈ (∞Met‘𝑋) ∧ 𝑃 ∈ 𝑋 ∧ 𝑥 ∈ 𝑋) → (𝑃𝐷𝑥) ∈ ℝ*) | |
8 | 7 | 3expa 1116 | . . . . . . . . 9 ⊢ (((𝐷 ∈ (∞Met‘𝑋) ∧ 𝑃 ∈ 𝑋) ∧ 𝑥 ∈ 𝑋) → (𝑃𝐷𝑥) ∈ ℝ*) |
9 | 8 | 3adantl3 1166 | . . . . . . . 8 ⊢ (((𝐷 ∈ (∞Met‘𝑋) ∧ 𝑃 ∈ 𝑋 ∧ 𝑅 ∈ ℝ*) ∧ 𝑥 ∈ 𝑋) → (𝑃𝐷𝑥) ∈ ℝ*) |
10 | simpl3 1191 | . . . . . . . 8 ⊢ (((𝐷 ∈ (∞Met‘𝑋) ∧ 𝑃 ∈ 𝑋 ∧ 𝑅 ∈ ℝ*) ∧ 𝑥 ∈ 𝑋) → 𝑅 ∈ ℝ*) | |
11 | xrlelttr 12918 | . . . . . . . 8 ⊢ ((0 ∈ ℝ* ∧ (𝑃𝐷𝑥) ∈ ℝ* ∧ 𝑅 ∈ ℝ*) → ((0 ≤ (𝑃𝐷𝑥) ∧ (𝑃𝐷𝑥) < 𝑅) → 0 < 𝑅)) | |
12 | 6, 9, 10, 11 | mp3an2i 1464 | . . . . . . 7 ⊢ (((𝐷 ∈ (∞Met‘𝑋) ∧ 𝑃 ∈ 𝑋 ∧ 𝑅 ∈ ℝ*) ∧ 𝑥 ∈ 𝑋) → ((0 ≤ (𝑃𝐷𝑥) ∧ (𝑃𝐷𝑥) < 𝑅) → 0 < 𝑅)) |
13 | 5, 12 | mpand 691 | . . . . . 6 ⊢ (((𝐷 ∈ (∞Met‘𝑋) ∧ 𝑃 ∈ 𝑋 ∧ 𝑅 ∈ ℝ*) ∧ 𝑥 ∈ 𝑋) → ((𝑃𝐷𝑥) < 𝑅 → 0 < 𝑅)) |
14 | 13 | expimpd 453 | . . . . 5 ⊢ ((𝐷 ∈ (∞Met‘𝑋) ∧ 𝑃 ∈ 𝑋 ∧ 𝑅 ∈ ℝ*) → ((𝑥 ∈ 𝑋 ∧ (𝑃𝐷𝑥) < 𝑅) → 0 < 𝑅)) |
15 | 2, 14 | sylbid 239 | . . . 4 ⊢ ((𝐷 ∈ (∞Met‘𝑋) ∧ 𝑃 ∈ 𝑋 ∧ 𝑅 ∈ ℝ*) → (𝑥 ∈ (𝑃(ball‘𝐷)𝑅) → 0 < 𝑅)) |
16 | 15 | exlimdv 1932 | . . 3 ⊢ ((𝐷 ∈ (∞Met‘𝑋) ∧ 𝑃 ∈ 𝑋 ∧ 𝑅 ∈ ℝ*) → (∃𝑥 𝑥 ∈ (𝑃(ball‘𝐷)𝑅) → 0 < 𝑅)) |
17 | 1, 16 | syl5bi 241 | . 2 ⊢ ((𝐷 ∈ (∞Met‘𝑋) ∧ 𝑃 ∈ 𝑋 ∧ 𝑅 ∈ ℝ*) → ((𝑃(ball‘𝐷)𝑅) ≠ ∅ → 0 < 𝑅)) |
18 | xblcntr 23592 | . . . . . 6 ⊢ ((𝐷 ∈ (∞Met‘𝑋) ∧ 𝑃 ∈ 𝑋 ∧ (𝑅 ∈ ℝ* ∧ 0 < 𝑅)) → 𝑃 ∈ (𝑃(ball‘𝐷)𝑅)) | |
19 | 18 | ne0d 4272 | . . . . 5 ⊢ ((𝐷 ∈ (∞Met‘𝑋) ∧ 𝑃 ∈ 𝑋 ∧ (𝑅 ∈ ℝ* ∧ 0 < 𝑅)) → (𝑃(ball‘𝐷)𝑅) ≠ ∅) |
20 | 19 | 3expa 1116 | . . . 4 ⊢ (((𝐷 ∈ (∞Met‘𝑋) ∧ 𝑃 ∈ 𝑋) ∧ (𝑅 ∈ ℝ* ∧ 0 < 𝑅)) → (𝑃(ball‘𝐷)𝑅) ≠ ∅) |
21 | 20 | expr 456 | . . 3 ⊢ (((𝐷 ∈ (∞Met‘𝑋) ∧ 𝑃 ∈ 𝑋) ∧ 𝑅 ∈ ℝ*) → (0 < 𝑅 → (𝑃(ball‘𝐷)𝑅) ≠ ∅)) |
22 | 21 | 3impa 1108 | . 2 ⊢ ((𝐷 ∈ (∞Met‘𝑋) ∧ 𝑃 ∈ 𝑋 ∧ 𝑅 ∈ ℝ*) → (0 < 𝑅 → (𝑃(ball‘𝐷)𝑅) ≠ ∅)) |
23 | 17, 22 | impbid 211 | 1 ⊢ ((𝐷 ∈ (∞Met‘𝑋) ∧ 𝑃 ∈ 𝑋 ∧ 𝑅 ∈ ℝ*) → ((𝑃(ball‘𝐷)𝑅) ≠ ∅ ↔ 0 < 𝑅)) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ↔ wb 205 ∧ wa 395 ∧ w3a 1085 ∃wex 1777 ∈ wcel 2101 ≠ wne 2938 ∅c0 4259 class class class wbr 5077 ‘cfv 6447 (class class class)co 7295 0cc0 10899 ℝ*cxr 11036 < clt 11037 ≤ cle 11038 ∞Metcxmet 20610 ballcbl 20612 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1793 ax-4 1807 ax-5 1909 ax-6 1967 ax-7 2007 ax-8 2103 ax-9 2111 ax-10 2132 ax-11 2149 ax-12 2166 ax-ext 2704 ax-sep 5226 ax-nul 5233 ax-pow 5291 ax-pr 5355 ax-un 7608 ax-cnex 10955 ax-resscn 10956 ax-1cn 10957 ax-icn 10958 ax-addcl 10959 ax-addrcl 10960 ax-mulcl 10961 ax-mulrcl 10962 ax-mulcom 10963 ax-addass 10964 ax-mulass 10965 ax-distr 10966 ax-i2m1 10967 ax-1ne0 10968 ax-1rid 10969 ax-rnegex 10970 ax-rrecex 10971 ax-cnre 10972 ax-pre-lttri 10973 ax-pre-lttrn 10974 ax-pre-ltadd 10975 ax-pre-mulgt0 10976 |
This theorem depends on definitions: df-bi 206 df-an 396 df-or 844 df-3or 1086 df-3an 1087 df-tru 1540 df-fal 1550 df-ex 1778 df-nf 1782 df-sb 2063 df-mo 2535 df-eu 2564 df-clab 2711 df-cleq 2725 df-clel 2811 df-nfc 2884 df-ne 2939 df-nel 3045 df-ral 3060 df-rex 3069 df-rmo 3222 df-reu 3223 df-rab 3224 df-v 3436 df-sbc 3719 df-csb 3835 df-dif 3892 df-un 3894 df-in 3896 df-ss 3906 df-nul 4260 df-if 4463 df-pw 4538 df-sn 4565 df-pr 4567 df-op 4571 df-uni 4842 df-iun 4929 df-br 5078 df-opab 5140 df-mpt 5161 df-id 5491 df-po 5505 df-so 5506 df-xp 5597 df-rel 5598 df-cnv 5599 df-co 5600 df-dm 5601 df-rn 5602 df-res 5603 df-ima 5604 df-iota 6399 df-fun 6449 df-fn 6450 df-f 6451 df-f1 6452 df-fo 6453 df-f1o 6454 df-fv 6455 df-riota 7252 df-ov 7298 df-oprab 7299 df-mpo 7300 df-1st 7851 df-2nd 7852 df-er 8518 df-map 8637 df-en 8754 df-dom 8755 df-sdom 8756 df-pnf 11039 df-mnf 11040 df-xr 11041 df-ltxr 11042 df-le 11043 df-sub 11235 df-neg 11236 df-div 11661 df-2 12064 df-rp 12759 df-xneg 12876 df-xadd 12877 df-xmul 12878 df-psmet 20617 df-xmet 20618 df-bl 20620 |
This theorem is referenced by: prdsxmslem2 23713 blssioo 23986 metdstri 24042 blbnd 35973 prdsbnd2 35981 |
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