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Mirrors > Home > ILE Home > Th. List > bdmet | GIF version |
Description: The standard bounded metric is a proper metric given an extended metric and a positive real cutoff. (Contributed by Mario Carneiro, 26-Aug-2015.) (Revised by Jim Kingdon, 19-May-2023.) |
Ref | Expression |
---|---|
stdbdmet.1 | ⊢ 𝐷 = (𝑥 ∈ 𝑋, 𝑦 ∈ 𝑋 ↦ inf({(𝑥𝐶𝑦), 𝑅}, ℝ*, < )) |
Ref | Expression |
---|---|
bdmet | ⊢ ((𝐶 ∈ (∞Met‘𝑋) ∧ 𝑅 ∈ ℝ+) → 𝐷 ∈ (Met‘𝑋)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | rpxr 9657 | . . . 4 ⊢ (𝑅 ∈ ℝ+ → 𝑅 ∈ ℝ*) | |
2 | rpgt0 9661 | . . . 4 ⊢ (𝑅 ∈ ℝ+ → 0 < 𝑅) | |
3 | 1, 2 | jca 306 | . . 3 ⊢ (𝑅 ∈ ℝ+ → (𝑅 ∈ ℝ* ∧ 0 < 𝑅)) |
4 | stdbdmet.1 | . . . . 5 ⊢ 𝐷 = (𝑥 ∈ 𝑋, 𝑦 ∈ 𝑋 ↦ inf({(𝑥𝐶𝑦), 𝑅}, ℝ*, < )) | |
5 | 4 | bdxmet 13872 | . . . 4 ⊢ ((𝐶 ∈ (∞Met‘𝑋) ∧ 𝑅 ∈ ℝ* ∧ 0 < 𝑅) → 𝐷 ∈ (∞Met‘𝑋)) |
6 | 5 | 3expb 1204 | . . 3 ⊢ ((𝐶 ∈ (∞Met‘𝑋) ∧ (𝑅 ∈ ℝ* ∧ 0 < 𝑅)) → 𝐷 ∈ (∞Met‘𝑋)) |
7 | 3, 6 | sylan2 286 | . 2 ⊢ ((𝐶 ∈ (∞Met‘𝑋) ∧ 𝑅 ∈ ℝ+) → 𝐷 ∈ (∞Met‘𝑋)) |
8 | xmetcl 13723 | . . . . . . . 8 ⊢ ((𝐶 ∈ (∞Met‘𝑋) ∧ 𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋) → (𝑥𝐶𝑦) ∈ ℝ*) | |
9 | 8 | 3expb 1204 | . . . . . . 7 ⊢ ((𝐶 ∈ (∞Met‘𝑋) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) → (𝑥𝐶𝑦) ∈ ℝ*) |
10 | 9 | adantlr 477 | . . . . . 6 ⊢ (((𝐶 ∈ (∞Met‘𝑋) ∧ 𝑅 ∈ ℝ+) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) → (𝑥𝐶𝑦) ∈ ℝ*) |
11 | 1 | ad2antlr 489 | . . . . . 6 ⊢ (((𝐶 ∈ (∞Met‘𝑋) ∧ 𝑅 ∈ ℝ+) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) → 𝑅 ∈ ℝ*) |
12 | xrmincl 11267 | . . . . . 6 ⊢ (((𝑥𝐶𝑦) ∈ ℝ* ∧ 𝑅 ∈ ℝ*) → inf({(𝑥𝐶𝑦), 𝑅}, ℝ*, < ) ∈ ℝ*) | |
13 | 10, 11, 12 | syl2anc 411 | . . . . 5 ⊢ (((𝐶 ∈ (∞Met‘𝑋) ∧ 𝑅 ∈ ℝ+) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) → inf({(𝑥𝐶𝑦), 𝑅}, ℝ*, < ) ∈ ℝ*) |
14 | rpre 9656 | . . . . . 6 ⊢ (𝑅 ∈ ℝ+ → 𝑅 ∈ ℝ) | |
15 | 14 | ad2antlr 489 | . . . . 5 ⊢ (((𝐶 ∈ (∞Met‘𝑋) ∧ 𝑅 ∈ ℝ+) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) → 𝑅 ∈ ℝ) |
16 | xmetge0 13736 | . . . . . . . 8 ⊢ ((𝐶 ∈ (∞Met‘𝑋) ∧ 𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋) → 0 ≤ (𝑥𝐶𝑦)) | |
17 | 16 | 3expb 1204 | . . . . . . 7 ⊢ ((𝐶 ∈ (∞Met‘𝑋) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) → 0 ≤ (𝑥𝐶𝑦)) |
18 | 17 | adantlr 477 | . . . . . 6 ⊢ (((𝐶 ∈ (∞Met‘𝑋) ∧ 𝑅 ∈ ℝ+) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) → 0 ≤ (𝑥𝐶𝑦)) |
19 | rpge0 9662 | . . . . . . 7 ⊢ (𝑅 ∈ ℝ+ → 0 ≤ 𝑅) | |
20 | 19 | ad2antlr 489 | . . . . . 6 ⊢ (((𝐶 ∈ (∞Met‘𝑋) ∧ 𝑅 ∈ ℝ+) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) → 0 ≤ 𝑅) |
21 | 0xr 8000 | . . . . . . 7 ⊢ 0 ∈ ℝ* | |
22 | xrlemininf 11272 | . . . . . . 7 ⊢ ((0 ∈ ℝ* ∧ (𝑥𝐶𝑦) ∈ ℝ* ∧ 𝑅 ∈ ℝ*) → (0 ≤ inf({(𝑥𝐶𝑦), 𝑅}, ℝ*, < ) ↔ (0 ≤ (𝑥𝐶𝑦) ∧ 0 ≤ 𝑅))) | |
23 | 21, 10, 11, 22 | mp3an2i 1342 | . . . . . 6 ⊢ (((𝐶 ∈ (∞Met‘𝑋) ∧ 𝑅 ∈ ℝ+) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) → (0 ≤ inf({(𝑥𝐶𝑦), 𝑅}, ℝ*, < ) ↔ (0 ≤ (𝑥𝐶𝑦) ∧ 0 ≤ 𝑅))) |
24 | 18, 20, 23 | mpbir2and 944 | . . . . 5 ⊢ (((𝐶 ∈ (∞Met‘𝑋) ∧ 𝑅 ∈ ℝ+) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) → 0 ≤ inf({(𝑥𝐶𝑦), 𝑅}, ℝ*, < )) |
25 | xrmin2inf 11269 | . . . . . 6 ⊢ (((𝑥𝐶𝑦) ∈ ℝ* ∧ 𝑅 ∈ ℝ*) → inf({(𝑥𝐶𝑦), 𝑅}, ℝ*, < ) ≤ 𝑅) | |
26 | 10, 11, 25 | syl2anc 411 | . . . . 5 ⊢ (((𝐶 ∈ (∞Met‘𝑋) ∧ 𝑅 ∈ ℝ+) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) → inf({(𝑥𝐶𝑦), 𝑅}, ℝ*, < ) ≤ 𝑅) |
27 | xrrege0 9821 | . . . . 5 ⊢ (((inf({(𝑥𝐶𝑦), 𝑅}, ℝ*, < ) ∈ ℝ* ∧ 𝑅 ∈ ℝ) ∧ (0 ≤ inf({(𝑥𝐶𝑦), 𝑅}, ℝ*, < ) ∧ inf({(𝑥𝐶𝑦), 𝑅}, ℝ*, < ) ≤ 𝑅)) → inf({(𝑥𝐶𝑦), 𝑅}, ℝ*, < ) ∈ ℝ) | |
28 | 13, 15, 24, 26, 27 | syl22anc 1239 | . . . 4 ⊢ (((𝐶 ∈ (∞Met‘𝑋) ∧ 𝑅 ∈ ℝ+) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) → inf({(𝑥𝐶𝑦), 𝑅}, ℝ*, < ) ∈ ℝ) |
29 | 28 | ralrimivva 2559 | . . 3 ⊢ ((𝐶 ∈ (∞Met‘𝑋) ∧ 𝑅 ∈ ℝ+) → ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑋 inf({(𝑥𝐶𝑦), 𝑅}, ℝ*, < ) ∈ ℝ) |
30 | 4 | fmpo 6199 | . . 3 ⊢ (∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑋 inf({(𝑥𝐶𝑦), 𝑅}, ℝ*, < ) ∈ ℝ ↔ 𝐷:(𝑋 × 𝑋)⟶ℝ) |
31 | 29, 30 | sylib 122 | . 2 ⊢ ((𝐶 ∈ (∞Met‘𝑋) ∧ 𝑅 ∈ ℝ+) → 𝐷:(𝑋 × 𝑋)⟶ℝ) |
32 | ismet2 13725 | . 2 ⊢ (𝐷 ∈ (Met‘𝑋) ↔ (𝐷 ∈ (∞Met‘𝑋) ∧ 𝐷:(𝑋 × 𝑋)⟶ℝ)) | |
33 | 7, 31, 32 | sylanbrc 417 | 1 ⊢ ((𝐶 ∈ (∞Met‘𝑋) ∧ 𝑅 ∈ ℝ+) → 𝐷 ∈ (Met‘𝑋)) |
Colors of variables: wff set class |
Syntax hints: → wi 4 ∧ wa 104 ↔ wb 105 = wceq 1353 ∈ wcel 2148 ∀wral 2455 {cpr 3593 class class class wbr 4002 × cxp 4623 ⟶wf 5211 ‘cfv 5215 (class class class)co 5872 ∈ cmpo 5874 infcinf 6979 ℝcr 7807 0cc0 7808 ℝ*cxr 7987 < clt 7988 ≤ cle 7989 ℝ+crp 9649 ∞Metcxmet 13309 Metcmet 13310 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 106 ax-ia2 107 ax-ia3 108 ax-in1 614 ax-in2 615 ax-io 709 ax-5 1447 ax-7 1448 ax-gen 1449 ax-ie1 1493 ax-ie2 1494 ax-8 1504 ax-10 1505 ax-11 1506 ax-i12 1507 ax-bndl 1509 ax-4 1510 ax-17 1526 ax-i9 1530 ax-ial 1534 ax-i5r 1535 ax-13 2150 ax-14 2151 ax-ext 2159 ax-coll 4117 ax-sep 4120 ax-nul 4128 ax-pow 4173 ax-pr 4208 ax-un 4432 ax-setind 4535 ax-iinf 4586 ax-cnex 7899 ax-resscn 7900 ax-1cn 7901 ax-1re 7902 ax-icn 7903 ax-addcl 7904 ax-addrcl 7905 ax-mulcl 7906 ax-mulrcl 7907 ax-addcom 7908 ax-mulcom 7909 ax-addass 7910 ax-mulass 7911 ax-distr 7912 ax-i2m1 7913 ax-0lt1 7914 ax-1rid 7915 ax-0id 7916 ax-rnegex 7917 ax-precex 7918 ax-cnre 7919 ax-pre-ltirr 7920 ax-pre-ltwlin 7921 ax-pre-lttrn 7922 ax-pre-apti 7923 ax-pre-ltadd 7924 ax-pre-mulgt0 7925 ax-pre-mulext 7926 ax-arch 7927 ax-caucvg 7928 |
This theorem depends on definitions: df-bi 117 df-dc 835 df-3or 979 df-3an 980 df-tru 1356 df-fal 1359 df-nf 1461 df-sb 1763 df-eu 2029 df-mo 2030 df-clab 2164 df-cleq 2170 df-clel 2173 df-nfc 2308 df-ne 2348 df-nel 2443 df-ral 2460 df-rex 2461 df-reu 2462 df-rmo 2463 df-rab 2464 df-v 2739 df-sbc 2963 df-csb 3058 df-dif 3131 df-un 3133 df-in 3135 df-ss 3142 df-nul 3423 df-if 3535 df-pw 3577 df-sn 3598 df-pr 3599 df-op 3601 df-uni 3810 df-int 3845 df-iun 3888 df-br 4003 df-opab 4064 df-mpt 4065 df-tr 4101 df-id 4292 df-po 4295 df-iso 4296 df-iord 4365 df-on 4367 df-ilim 4368 df-suc 4370 df-iom 4589 df-xp 4631 df-rel 4632 df-cnv 4633 df-co 4634 df-dm 4635 df-rn 4636 df-res 4637 df-ima 4638 df-iota 5177 df-fun 5217 df-fn 5218 df-f 5219 df-f1 5220 df-fo 5221 df-f1o 5222 df-fv 5223 df-isom 5224 df-riota 5828 df-ov 5875 df-oprab 5876 df-mpo 5877 df-1st 6138 df-2nd 6139 df-recs 6303 df-frec 6389 df-map 6647 df-sup 6980 df-inf 6981 df-pnf 7990 df-mnf 7991 df-xr 7992 df-ltxr 7993 df-le 7994 df-sub 8126 df-neg 8127 df-reap 8528 df-ap 8535 df-div 8626 df-inn 8916 df-2 8974 df-3 8975 df-4 8976 df-n0 9173 df-z 9250 df-uz 9525 df-rp 9650 df-xneg 9768 df-xadd 9769 df-icc 9891 df-seqfrec 10441 df-exp 10515 df-cj 10844 df-re 10845 df-im 10846 df-rsqrt 11000 df-abs 11001 df-xmet 13317 df-met 13318 |
This theorem is referenced by: mopnex 13876 |
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