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Mirrors > Home > MPE Home > Th. List > itggt0 | Structured version Visualization version GIF version |
Description: The integral of a strictly positive function is positive. (Contributed by Mario Carneiro, 30-Aug-2014.) |
Ref | Expression |
---|---|
itggt0.1 | ⊢ (𝜑 → 0 < (vol‘𝐴)) |
itggt0.2 | ⊢ (𝜑 → (𝑥 ∈ 𝐴 ↦ 𝐵) ∈ 𝐿1) |
itggt0.3 | ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐵 ∈ ℝ+) |
Ref | Expression |
---|---|
itggt0 | ⊢ (𝜑 → 0 < ∫𝐴𝐵 d𝑥) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | itggt0.2 | . . . . 5 ⊢ (𝜑 → (𝑥 ∈ 𝐴 ↦ 𝐵) ∈ 𝐿1) | |
2 | iblmbf 24368 | . . . . 5 ⊢ ((𝑥 ∈ 𝐴 ↦ 𝐵) ∈ 𝐿1 → (𝑥 ∈ 𝐴 ↦ 𝐵) ∈ MblFn) | |
3 | 1, 2 | syl 17 | . . . 4 ⊢ (𝜑 → (𝑥 ∈ 𝐴 ↦ 𝐵) ∈ MblFn) |
4 | itggt0.3 | . . . 4 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐵 ∈ ℝ+) | |
5 | 3, 4 | mbfdm2 24238 | . . 3 ⊢ (𝜑 → 𝐴 ∈ dom vol) |
6 | itggt0.1 | . . 3 ⊢ (𝜑 → 0 < (vol‘𝐴)) | |
7 | 4 | rpred 12432 | . . . . . . 7 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐵 ∈ ℝ) |
8 | 4 | rpge0d 12436 | . . . . . . 7 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 0 ≤ 𝐵) |
9 | elrege0 12843 | . . . . . . 7 ⊢ (𝐵 ∈ (0[,)+∞) ↔ (𝐵 ∈ ℝ ∧ 0 ≤ 𝐵)) | |
10 | 7, 8, 9 | sylanbrc 585 | . . . . . 6 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐵 ∈ (0[,)+∞)) |
11 | 0e0icopnf 12847 | . . . . . . 7 ⊢ 0 ∈ (0[,)+∞) | |
12 | 11 | a1i 11 | . . . . . 6 ⊢ ((𝜑 ∧ ¬ 𝑥 ∈ 𝐴) → 0 ∈ (0[,)+∞)) |
13 | 10, 12 | ifclda 4501 | . . . . 5 ⊢ (𝜑 → if(𝑥 ∈ 𝐴, 𝐵, 0) ∈ (0[,)+∞)) |
14 | 13 | adantr 483 | . . . 4 ⊢ ((𝜑 ∧ 𝑥 ∈ ℝ) → if(𝑥 ∈ 𝐴, 𝐵, 0) ∈ (0[,)+∞)) |
15 | 14 | fmpttd 6879 | . . 3 ⊢ (𝜑 → (𝑥 ∈ ℝ ↦ if(𝑥 ∈ 𝐴, 𝐵, 0)):ℝ⟶(0[,)+∞)) |
16 | mblss 24132 | . . . . 5 ⊢ (𝐴 ∈ dom vol → 𝐴 ⊆ ℝ) | |
17 | 5, 16 | syl 17 | . . . 4 ⊢ (𝜑 → 𝐴 ⊆ ℝ) |
18 | rembl 24141 | . . . . 5 ⊢ ℝ ∈ dom vol | |
19 | 18 | a1i 11 | . . . 4 ⊢ (𝜑 → ℝ ∈ dom vol) |
20 | 13 | adantr 483 | . . . 4 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → if(𝑥 ∈ 𝐴, 𝐵, 0) ∈ (0[,)+∞)) |
21 | eldifn 4104 | . . . . . 6 ⊢ (𝑥 ∈ (ℝ ∖ 𝐴) → ¬ 𝑥 ∈ 𝐴) | |
22 | 21 | adantl 484 | . . . . 5 ⊢ ((𝜑 ∧ 𝑥 ∈ (ℝ ∖ 𝐴)) → ¬ 𝑥 ∈ 𝐴) |
23 | 22 | iffalsed 4478 | . . . 4 ⊢ ((𝜑 ∧ 𝑥 ∈ (ℝ ∖ 𝐴)) → if(𝑥 ∈ 𝐴, 𝐵, 0) = 0) |
24 | iftrue 4473 | . . . . . 6 ⊢ (𝑥 ∈ 𝐴 → if(𝑥 ∈ 𝐴, 𝐵, 0) = 𝐵) | |
25 | 24 | mpteq2ia 5157 | . . . . 5 ⊢ (𝑥 ∈ 𝐴 ↦ if(𝑥 ∈ 𝐴, 𝐵, 0)) = (𝑥 ∈ 𝐴 ↦ 𝐵) |
26 | 25, 3 | eqeltrid 2917 | . . . 4 ⊢ (𝜑 → (𝑥 ∈ 𝐴 ↦ if(𝑥 ∈ 𝐴, 𝐵, 0)) ∈ MblFn) |
27 | 17, 19, 20, 23, 26 | mbfss 24247 | . . 3 ⊢ (𝜑 → (𝑥 ∈ ℝ ↦ if(𝑥 ∈ 𝐴, 𝐵, 0)) ∈ MblFn) |
28 | 4 | rpgt0d 12435 | . . . . . . 7 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 0 < 𝐵) |
29 | 17 | sselda 3967 | . . . . . . . . 9 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝑥 ∈ ℝ) |
30 | 24 | adantl 484 | . . . . . . . . . 10 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → if(𝑥 ∈ 𝐴, 𝐵, 0) = 𝐵) |
31 | 30, 4 | eqeltrd 2913 | . . . . . . . . 9 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → if(𝑥 ∈ 𝐴, 𝐵, 0) ∈ ℝ+) |
32 | eqid 2821 | . . . . . . . . . 10 ⊢ (𝑥 ∈ ℝ ↦ if(𝑥 ∈ 𝐴, 𝐵, 0)) = (𝑥 ∈ ℝ ↦ if(𝑥 ∈ 𝐴, 𝐵, 0)) | |
33 | 32 | fvmpt2 6779 | . . . . . . . . 9 ⊢ ((𝑥 ∈ ℝ ∧ if(𝑥 ∈ 𝐴, 𝐵, 0) ∈ ℝ+) → ((𝑥 ∈ ℝ ↦ if(𝑥 ∈ 𝐴, 𝐵, 0))‘𝑥) = if(𝑥 ∈ 𝐴, 𝐵, 0)) |
34 | 29, 31, 33 | syl2anc 586 | . . . . . . . 8 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → ((𝑥 ∈ ℝ ↦ if(𝑥 ∈ 𝐴, 𝐵, 0))‘𝑥) = if(𝑥 ∈ 𝐴, 𝐵, 0)) |
35 | 34, 30 | eqtrd 2856 | . . . . . . 7 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → ((𝑥 ∈ ℝ ↦ if(𝑥 ∈ 𝐴, 𝐵, 0))‘𝑥) = 𝐵) |
36 | 28, 35 | breqtrrd 5094 | . . . . . 6 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 0 < ((𝑥 ∈ ℝ ↦ if(𝑥 ∈ 𝐴, 𝐵, 0))‘𝑥)) |
37 | 36 | ralrimiva 3182 | . . . . 5 ⊢ (𝜑 → ∀𝑥 ∈ 𝐴 0 < ((𝑥 ∈ ℝ ↦ if(𝑥 ∈ 𝐴, 𝐵, 0))‘𝑥)) |
38 | nfcv 2977 | . . . . . . 7 ⊢ Ⅎ𝑥0 | |
39 | nfcv 2977 | . . . . . . 7 ⊢ Ⅎ𝑥 < | |
40 | nffvmpt1 6681 | . . . . . . 7 ⊢ Ⅎ𝑥((𝑥 ∈ ℝ ↦ if(𝑥 ∈ 𝐴, 𝐵, 0))‘𝑦) | |
41 | 38, 39, 40 | nfbr 5113 | . . . . . 6 ⊢ Ⅎ𝑥0 < ((𝑥 ∈ ℝ ↦ if(𝑥 ∈ 𝐴, 𝐵, 0))‘𝑦) |
42 | nfv 1915 | . . . . . 6 ⊢ Ⅎ𝑦0 < ((𝑥 ∈ ℝ ↦ if(𝑥 ∈ 𝐴, 𝐵, 0))‘𝑥) | |
43 | fveq2 6670 | . . . . . . 7 ⊢ (𝑦 = 𝑥 → ((𝑥 ∈ ℝ ↦ if(𝑥 ∈ 𝐴, 𝐵, 0))‘𝑦) = ((𝑥 ∈ ℝ ↦ if(𝑥 ∈ 𝐴, 𝐵, 0))‘𝑥)) | |
44 | 43 | breq2d 5078 | . . . . . 6 ⊢ (𝑦 = 𝑥 → (0 < ((𝑥 ∈ ℝ ↦ if(𝑥 ∈ 𝐴, 𝐵, 0))‘𝑦) ↔ 0 < ((𝑥 ∈ ℝ ↦ if(𝑥 ∈ 𝐴, 𝐵, 0))‘𝑥))) |
45 | 41, 42, 44 | cbvralw 3441 | . . . . 5 ⊢ (∀𝑦 ∈ 𝐴 0 < ((𝑥 ∈ ℝ ↦ if(𝑥 ∈ 𝐴, 𝐵, 0))‘𝑦) ↔ ∀𝑥 ∈ 𝐴 0 < ((𝑥 ∈ ℝ ↦ if(𝑥 ∈ 𝐴, 𝐵, 0))‘𝑥)) |
46 | 37, 45 | sylibr 236 | . . . 4 ⊢ (𝜑 → ∀𝑦 ∈ 𝐴 0 < ((𝑥 ∈ ℝ ↦ if(𝑥 ∈ 𝐴, 𝐵, 0))‘𝑦)) |
47 | 46 | r19.21bi 3208 | . . 3 ⊢ ((𝜑 ∧ 𝑦 ∈ 𝐴) → 0 < ((𝑥 ∈ ℝ ↦ if(𝑥 ∈ 𝐴, 𝐵, 0))‘𝑦)) |
48 | 5, 6, 15, 27, 47 | itg2gt0 24361 | . 2 ⊢ (𝜑 → 0 < (∫2‘(𝑥 ∈ ℝ ↦ if(𝑥 ∈ 𝐴, 𝐵, 0)))) |
49 | 7, 1, 8 | itgposval 24396 | . 2 ⊢ (𝜑 → ∫𝐴𝐵 d𝑥 = (∫2‘(𝑥 ∈ ℝ ↦ if(𝑥 ∈ 𝐴, 𝐵, 0)))) |
50 | 48, 49 | breqtrrd 5094 | 1 ⊢ (𝜑 → 0 < ∫𝐴𝐵 d𝑥) |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 → wi 4 ∧ wa 398 = wceq 1537 ∈ wcel 2114 ∀wral 3138 ∖ cdif 3933 ⊆ wss 3936 ifcif 4467 class class class wbr 5066 ↦ cmpt 5146 dom cdm 5555 ‘cfv 6355 (class class class)co 7156 ℝcr 10536 0cc0 10537 +∞cpnf 10672 < clt 10675 ≤ cle 10676 ℝ+crp 12390 [,)cico 12741 volcvol 24064 MblFncmbf 24215 ∫2citg2 24217 𝐿1cibl 24218 ∫citg 24219 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1796 ax-4 1810 ax-5 1911 ax-6 1970 ax-7 2015 ax-8 2116 ax-9 2124 ax-10 2145 ax-11 2161 ax-12 2177 ax-ext 2793 ax-rep 5190 ax-sep 5203 ax-nul 5210 ax-pow 5266 ax-pr 5330 ax-un 7461 ax-inf2 9104 ax-cc 9857 ax-cnex 10593 ax-resscn 10594 ax-1cn 10595 ax-icn 10596 ax-addcl 10597 ax-addrcl 10598 ax-mulcl 10599 ax-mulrcl 10600 ax-mulcom 10601 ax-addass 10602 ax-mulass 10603 ax-distr 10604 ax-i2m1 10605 ax-1ne0 10606 ax-1rid 10607 ax-rnegex 10608 ax-rrecex 10609 ax-cnre 10610 ax-pre-lttri 10611 ax-pre-lttrn 10612 ax-pre-ltadd 10613 ax-pre-mulgt0 10614 ax-pre-sup 10615 ax-addf 10616 |
This theorem depends on definitions: df-bi 209 df-an 399 df-or 844 df-3or 1084 df-3an 1085 df-tru 1540 df-fal 1550 df-ex 1781 df-nf 1785 df-sb 2070 df-mo 2622 df-eu 2654 df-clab 2800 df-cleq 2814 df-clel 2893 df-nfc 2963 df-ne 3017 df-nel 3124 df-ral 3143 df-rex 3144 df-reu 3145 df-rmo 3146 df-rab 3147 df-v 3496 df-sbc 3773 df-csb 3884 df-dif 3939 df-un 3941 df-in 3943 df-ss 3952 df-pss 3954 df-nul 4292 df-if 4468 df-pw 4541 df-sn 4568 df-pr 4570 df-tp 4572 df-op 4574 df-uni 4839 df-int 4877 df-iun 4921 df-disj 5032 df-br 5067 df-opab 5129 df-mpt 5147 df-tr 5173 df-id 5460 df-eprel 5465 df-po 5474 df-so 5475 df-fr 5514 df-se 5515 df-we 5516 df-xp 5561 df-rel 5562 df-cnv 5563 df-co 5564 df-dm 5565 df-rn 5566 df-res 5567 df-ima 5568 df-pred 6148 df-ord 6194 df-on 6195 df-lim 6196 df-suc 6197 df-iota 6314 df-fun 6357 df-fn 6358 df-f 6359 df-f1 6360 df-fo 6361 df-f1o 6362 df-fv 6363 df-isom 6364 df-riota 7114 df-ov 7159 df-oprab 7160 df-mpo 7161 df-of 7409 df-ofr 7410 df-om 7581 df-1st 7689 df-2nd 7690 df-wrecs 7947 df-recs 8008 df-rdg 8046 df-1o 8102 df-2o 8103 df-oadd 8106 df-er 8289 df-map 8408 df-pm 8409 df-en 8510 df-dom 8511 df-sdom 8512 df-fin 8513 df-fi 8875 df-sup 8906 df-inf 8907 df-oi 8974 df-dju 9330 df-card 9368 df-pnf 10677 df-mnf 10678 df-xr 10679 df-ltxr 10680 df-le 10681 df-sub 10872 df-neg 10873 df-div 11298 df-nn 11639 df-2 11701 df-3 11702 df-4 11703 df-n0 11899 df-z 11983 df-uz 12245 df-q 12350 df-rp 12391 df-xneg 12508 df-xadd 12509 df-xmul 12510 df-ioo 12743 df-ico 12745 df-icc 12746 df-fz 12894 df-fzo 13035 df-fl 13163 df-mod 13239 df-seq 13371 df-exp 13431 df-hash 13692 df-cj 14458 df-re 14459 df-im 14460 df-sqrt 14594 df-abs 14595 df-clim 14845 df-rlim 14846 df-sum 15043 df-rest 16696 df-topgen 16717 df-psmet 20537 df-xmet 20538 df-met 20539 df-bl 20540 df-mopn 20541 df-top 21502 df-topon 21519 df-bases 21554 df-cmp 21995 df-cncf 23486 df-ovol 24065 df-vol 24066 df-mbf 24220 df-itg1 24221 df-itg2 24222 df-ibl 24223 df-itg 24224 df-0p 24271 |
This theorem is referenced by: ftc1lem4 24636 fdvposlt 31870 |
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