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Mirrors > Home > MPE Home > Th. List > mbfpos | Structured version Visualization version GIF version |
Description: The positive part of a measurable function is measurable. (Contributed by Mario Carneiro, 31-Jul-2014.) |
Ref | Expression |
---|---|
mbfpos.1 | ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐵 ∈ ℝ) |
mbfpos.2 | ⊢ (𝜑 → (𝑥 ∈ 𝐴 ↦ 𝐵) ∈ MblFn) |
Ref | Expression |
---|---|
mbfpos | ⊢ (𝜑 → (𝑥 ∈ 𝐴 ↦ if(0 ≤ 𝐵, 𝐵, 0)) ∈ MblFn) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | c0ex 10322 | . . . . . . 7 ⊢ 0 ∈ V | |
2 | 1 | fvconst2 6698 | . . . . . 6 ⊢ (𝑥 ∈ 𝐴 → ((𝐴 × {0})‘𝑥) = 0) |
3 | 2 | adantl 474 | . . . . 5 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → ((𝐴 × {0})‘𝑥) = 0) |
4 | simpr 478 | . . . . . 6 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝑥 ∈ 𝐴) | |
5 | mbfpos.1 | . . . . . 6 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐵 ∈ ℝ) | |
6 | eqid 2799 | . . . . . . 7 ⊢ (𝑥 ∈ 𝐴 ↦ 𝐵) = (𝑥 ∈ 𝐴 ↦ 𝐵) | |
7 | 6 | fvmpt2 6516 | . . . . . 6 ⊢ ((𝑥 ∈ 𝐴 ∧ 𝐵 ∈ ℝ) → ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥) = 𝐵) |
8 | 4, 5, 7 | syl2anc 580 | . . . . 5 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥) = 𝐵) |
9 | 3, 8 | breq12d 4856 | . . . 4 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → (((𝐴 × {0})‘𝑥) ≤ ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥) ↔ 0 ≤ 𝐵)) |
10 | 9, 8, 3 | ifbieq12d 4304 | . . 3 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → if(((𝐴 × {0})‘𝑥) ≤ ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥), ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥), ((𝐴 × {0})‘𝑥)) = if(0 ≤ 𝐵, 𝐵, 0)) |
11 | 10 | mpteq2dva 4937 | . 2 ⊢ (𝜑 → (𝑥 ∈ 𝐴 ↦ if(((𝐴 × {0})‘𝑥) ≤ ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥), ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥), ((𝐴 × {0})‘𝑥))) = (𝑥 ∈ 𝐴 ↦ if(0 ≤ 𝐵, 𝐵, 0))) |
12 | 0re 10330 | . . . . 5 ⊢ 0 ∈ ℝ | |
13 | 12 | fconst6 6310 | . . . 4 ⊢ (𝐴 × {0}):𝐴⟶ℝ |
14 | 13 | a1i 11 | . . 3 ⊢ (𝜑 → (𝐴 × {0}):𝐴⟶ℝ) |
15 | mbfpos.2 | . . . . 5 ⊢ (𝜑 → (𝑥 ∈ 𝐴 ↦ 𝐵) ∈ MblFn) | |
16 | 15, 5 | mbfdm2 23745 | . . . 4 ⊢ (𝜑 → 𝐴 ∈ dom vol) |
17 | 0cnd 10321 | . . . 4 ⊢ (𝜑 → 0 ∈ ℂ) | |
18 | mbfconst 23741 | . . . 4 ⊢ ((𝐴 ∈ dom vol ∧ 0 ∈ ℂ) → (𝐴 × {0}) ∈ MblFn) | |
19 | 16, 17, 18 | syl2anc 580 | . . 3 ⊢ (𝜑 → (𝐴 × {0}) ∈ MblFn) |
20 | 5 | fmpttd 6611 | . . 3 ⊢ (𝜑 → (𝑥 ∈ 𝐴 ↦ 𝐵):𝐴⟶ℝ) |
21 | nfcv 2941 | . . . 4 ⊢ Ⅎ𝑦if(((𝐴 × {0})‘𝑥) ≤ ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥), ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥), ((𝐴 × {0})‘𝑥)) | |
22 | nfcv 2941 | . . . . . 6 ⊢ Ⅎ𝑥((𝐴 × {0})‘𝑦) | |
23 | nfcv 2941 | . . . . . 6 ⊢ Ⅎ𝑥 ≤ | |
24 | nffvmpt1 6422 | . . . . . 6 ⊢ Ⅎ𝑥((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑦) | |
25 | 22, 23, 24 | nfbr 4890 | . . . . 5 ⊢ Ⅎ𝑥((𝐴 × {0})‘𝑦) ≤ ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑦) |
26 | 25, 24, 22 | nfif 4306 | . . . 4 ⊢ Ⅎ𝑥if(((𝐴 × {0})‘𝑦) ≤ ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑦), ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑦), ((𝐴 × {0})‘𝑦)) |
27 | fveq2 6411 | . . . . . 6 ⊢ (𝑥 = 𝑦 → ((𝐴 × {0})‘𝑥) = ((𝐴 × {0})‘𝑦)) | |
28 | fveq2 6411 | . . . . . 6 ⊢ (𝑥 = 𝑦 → ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥) = ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑦)) | |
29 | 27, 28 | breq12d 4856 | . . . . 5 ⊢ (𝑥 = 𝑦 → (((𝐴 × {0})‘𝑥) ≤ ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥) ↔ ((𝐴 × {0})‘𝑦) ≤ ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑦))) |
30 | 29, 28, 27 | ifbieq12d 4304 | . . . 4 ⊢ (𝑥 = 𝑦 → if(((𝐴 × {0})‘𝑥) ≤ ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥), ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥), ((𝐴 × {0})‘𝑥)) = if(((𝐴 × {0})‘𝑦) ≤ ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑦), ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑦), ((𝐴 × {0})‘𝑦))) |
31 | 21, 26, 30 | cbvmpt 4942 | . . 3 ⊢ (𝑥 ∈ 𝐴 ↦ if(((𝐴 × {0})‘𝑥) ≤ ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥), ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥), ((𝐴 × {0})‘𝑥))) = (𝑦 ∈ 𝐴 ↦ if(((𝐴 × {0})‘𝑦) ≤ ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑦), ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑦), ((𝐴 × {0})‘𝑦))) |
32 | 14, 19, 20, 15, 31 | mbfmax 23757 | . 2 ⊢ (𝜑 → (𝑥 ∈ 𝐴 ↦ if(((𝐴 × {0})‘𝑥) ≤ ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥), ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥), ((𝐴 × {0})‘𝑥))) ∈ MblFn) |
33 | 11, 32 | eqeltrrd 2879 | 1 ⊢ (𝜑 → (𝑥 ∈ 𝐴 ↦ if(0 ≤ 𝐵, 𝐵, 0)) ∈ MblFn) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 385 = wceq 1653 ∈ wcel 2157 ifcif 4277 {csn 4368 class class class wbr 4843 ↦ cmpt 4922 × cxp 5310 dom cdm 5312 ⟶wf 6097 ‘cfv 6101 ℂcc 10222 ℝcr 10223 0cc0 10224 ≤ cle 10364 volcvol 23571 MblFncmbf 23722 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1891 ax-4 1905 ax-5 2006 ax-6 2072 ax-7 2107 ax-8 2159 ax-9 2166 ax-10 2185 ax-11 2200 ax-12 2213 ax-13 2377 ax-ext 2777 ax-rep 4964 ax-sep 4975 ax-nul 4983 ax-pow 5035 ax-pr 5097 ax-un 7183 ax-inf2 8788 ax-cnex 10280 ax-resscn 10281 ax-1cn 10282 ax-icn 10283 ax-addcl 10284 ax-addrcl 10285 ax-mulcl 10286 ax-mulrcl 10287 ax-mulcom 10288 ax-addass 10289 ax-mulass 10290 ax-distr 10291 ax-i2m1 10292 ax-1ne0 10293 ax-1rid 10294 ax-rnegex 10295 ax-rrecex 10296 ax-cnre 10297 ax-pre-lttri 10298 ax-pre-lttrn 10299 ax-pre-ltadd 10300 ax-pre-mulgt0 10301 ax-pre-sup 10302 |
This theorem depends on definitions: df-bi 199 df-an 386 df-or 875 df-3or 1109 df-3an 1110 df-tru 1657 df-fal 1667 df-ex 1876 df-nf 1880 df-sb 2065 df-mo 2591 df-eu 2609 df-clab 2786 df-cleq 2792 df-clel 2795 df-nfc 2930 df-ne 2972 df-nel 3075 df-ral 3094 df-rex 3095 df-reu 3096 df-rmo 3097 df-rab 3098 df-v 3387 df-sbc 3634 df-csb 3729 df-dif 3772 df-un 3774 df-in 3776 df-ss 3783 df-pss 3785 df-nul 4116 df-if 4278 df-pw 4351 df-sn 4369 df-pr 4371 df-tp 4373 df-op 4375 df-uni 4629 df-int 4668 df-iun 4712 df-br 4844 df-opab 4906 df-mpt 4923 df-tr 4946 df-id 5220 df-eprel 5225 df-po 5233 df-so 5234 df-fr 5271 df-se 5272 df-we 5273 df-xp 5318 df-rel 5319 df-cnv 5320 df-co 5321 df-dm 5322 df-rn 5323 df-res 5324 df-ima 5325 df-pred 5898 df-ord 5944 df-on 5945 df-lim 5946 df-suc 5947 df-iota 6064 df-fun 6103 df-fn 6104 df-f 6105 df-f1 6106 df-fo 6107 df-f1o 6108 df-fv 6109 df-isom 6110 df-riota 6839 df-ov 6881 df-oprab 6882 df-mpt2 6883 df-of 7131 df-om 7300 df-1st 7401 df-2nd 7402 df-wrecs 7645 df-recs 7707 df-rdg 7745 df-1o 7799 df-2o 7800 df-oadd 7803 df-er 7982 df-map 8097 df-pm 8098 df-en 8196 df-dom 8197 df-sdom 8198 df-fin 8199 df-sup 8590 df-inf 8591 df-oi 8657 df-card 9051 df-cda 9278 df-pnf 10365 df-mnf 10366 df-xr 10367 df-ltxr 10368 df-le 10369 df-sub 10558 df-neg 10559 df-div 10977 df-nn 11313 df-2 11376 df-3 11377 df-n0 11581 df-z 11667 df-uz 11931 df-q 12034 df-rp 12075 df-xadd 12194 df-ioo 12428 df-ico 12430 df-icc 12431 df-fz 12581 df-fzo 12721 df-fl 12848 df-seq 13056 df-exp 13115 df-hash 13371 df-cj 14180 df-re 14181 df-im 14182 df-sqrt 14316 df-abs 14317 df-clim 14560 df-sum 14758 df-xmet 20061 df-met 20062 df-ovol 23572 df-vol 23573 df-mbf 23727 |
This theorem is referenced by: mbfposb 23761 mbfi1flimlem 23830 itgreval 23904 ibladdlem 23927 iblabslem 23935 mbfposadd 33945 ibladdnclem 33954 iblabsnclem 33961 itgmulc2nclem2 33965 |
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