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Mathbox for Thierry Arnoux |
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Mirrors > Home > MPE Home > Th. List > Mathboxes > signlem0 | Structured version Visualization version GIF version |
Description: Adding a zero as the highest coefficient does not change the parity of the sign changes. (Contributed by Thierry Arnoux, 12-Oct-2018.) |
Ref | Expression |
---|---|
signsv.p | ⊢ ⨣ = (𝑎 ∈ {-1, 0, 1}, 𝑏 ∈ {-1, 0, 1} ↦ if(𝑏 = 0, 𝑎, 𝑏)) |
signsv.w | ⊢ 𝑊 = {〈(Base‘ndx), {-1, 0, 1}〉, 〈(+g‘ndx), ⨣ 〉} |
signsv.t | ⊢ 𝑇 = (𝑓 ∈ Word ℝ ↦ (𝑛 ∈ (0..^(♯‘𝑓)) ↦ (𝑊 Σg (𝑖 ∈ (0...𝑛) ↦ (sgn‘(𝑓‘𝑖)))))) |
signsv.v | ⊢ 𝑉 = (𝑓 ∈ Word ℝ ↦ Σ𝑗 ∈ (1..^(♯‘𝑓))if(((𝑇‘𝑓)‘𝑗) ≠ ((𝑇‘𝑓)‘(𝑗 − 1)), 1, 0)) |
Ref | Expression |
---|---|
signlem0 | ⊢ ((𝐹 ∈ (Word ℝ ∖ {∅}) ∧ (𝐹‘0) ≠ 0) → (𝑉‘(𝐹 ++ 〈“0”〉)) = (𝑉‘𝐹)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 0re 10666 | . . 3 ⊢ 0 ∈ ℝ | |
2 | signsv.p | . . . 4 ⊢ ⨣ = (𝑎 ∈ {-1, 0, 1}, 𝑏 ∈ {-1, 0, 1} ↦ if(𝑏 = 0, 𝑎, 𝑏)) | |
3 | signsv.w | . . . 4 ⊢ 𝑊 = {〈(Base‘ndx), {-1, 0, 1}〉, 〈(+g‘ndx), ⨣ 〉} | |
4 | signsv.t | . . . 4 ⊢ 𝑇 = (𝑓 ∈ Word ℝ ↦ (𝑛 ∈ (0..^(♯‘𝑓)) ↦ (𝑊 Σg (𝑖 ∈ (0...𝑛) ↦ (sgn‘(𝑓‘𝑖)))))) | |
5 | signsv.v | . . . 4 ⊢ 𝑉 = (𝑓 ∈ Word ℝ ↦ Σ𝑗 ∈ (1..^(♯‘𝑓))if(((𝑇‘𝑓)‘𝑗) ≠ ((𝑇‘𝑓)‘(𝑗 − 1)), 1, 0)) | |
6 | 2, 3, 4, 5 | signsvfn 32065 | . . 3 ⊢ (((𝐹 ∈ (Word ℝ ∖ {∅}) ∧ (𝐹‘0) ≠ 0) ∧ 0 ∈ ℝ) → (𝑉‘(𝐹 ++ 〈“0”〉)) = ((𝑉‘𝐹) + if((((𝑇‘𝐹)‘((♯‘𝐹) − 1)) · 0) < 0, 1, 0))) |
7 | 1, 6 | mpan2 691 | . 2 ⊢ ((𝐹 ∈ (Word ℝ ∖ {∅}) ∧ (𝐹‘0) ≠ 0) → (𝑉‘(𝐹 ++ 〈“0”〉)) = ((𝑉‘𝐹) + if((((𝑇‘𝐹)‘((♯‘𝐹) − 1)) · 0) < 0, 1, 0))) |
8 | 1 | ltnri 10772 | . . . . 5 ⊢ ¬ 0 < 0 |
9 | neg1cn 11773 | . . . . . . . . 9 ⊢ -1 ∈ ℂ | |
10 | ax-1cn 10618 | . . . . . . . . 9 ⊢ 1 ∈ ℂ | |
11 | prssi 4704 | . . . . . . . . 9 ⊢ ((-1 ∈ ℂ ∧ 1 ∈ ℂ) → {-1, 1} ⊆ ℂ) | |
12 | 9, 10, 11 | mp2an 692 | . . . . . . . 8 ⊢ {-1, 1} ⊆ ℂ |
13 | simpl 487 | . . . . . . . . . . 11 ⊢ ((𝐹 ∈ (Word ℝ ∖ {∅}) ∧ (𝐹‘0) ≠ 0) → 𝐹 ∈ (Word ℝ ∖ {∅})) | |
14 | eldifsn 4670 | . . . . . . . . . . 11 ⊢ (𝐹 ∈ (Word ℝ ∖ {∅}) ↔ (𝐹 ∈ Word ℝ ∧ 𝐹 ≠ ∅)) | |
15 | 13, 14 | sylib 221 | . . . . . . . . . 10 ⊢ ((𝐹 ∈ (Word ℝ ∖ {∅}) ∧ (𝐹‘0) ≠ 0) → (𝐹 ∈ Word ℝ ∧ 𝐹 ≠ ∅)) |
16 | lennncl 13918 | . . . . . . . . . 10 ⊢ ((𝐹 ∈ Word ℝ ∧ 𝐹 ≠ ∅) → (♯‘𝐹) ∈ ℕ) | |
17 | fzo0end 13163 | . . . . . . . . . 10 ⊢ ((♯‘𝐹) ∈ ℕ → ((♯‘𝐹) − 1) ∈ (0..^(♯‘𝐹))) | |
18 | 15, 16, 17 | 3syl 18 | . . . . . . . . 9 ⊢ ((𝐹 ∈ (Word ℝ ∖ {∅}) ∧ (𝐹‘0) ≠ 0) → ((♯‘𝐹) − 1) ∈ (0..^(♯‘𝐹))) |
19 | 2, 3, 4, 5 | signstfvcl 32056 | . . . . . . . . 9 ⊢ (((𝐹 ∈ (Word ℝ ∖ {∅}) ∧ (𝐹‘0) ≠ 0) ∧ ((♯‘𝐹) − 1) ∈ (0..^(♯‘𝐹))) → ((𝑇‘𝐹)‘((♯‘𝐹) − 1)) ∈ {-1, 1}) |
20 | 18, 19 | mpdan 687 | . . . . . . . 8 ⊢ ((𝐹 ∈ (Word ℝ ∖ {∅}) ∧ (𝐹‘0) ≠ 0) → ((𝑇‘𝐹)‘((♯‘𝐹) − 1)) ∈ {-1, 1}) |
21 | 12, 20 | sseldi 3886 | . . . . . . 7 ⊢ ((𝐹 ∈ (Word ℝ ∖ {∅}) ∧ (𝐹‘0) ≠ 0) → ((𝑇‘𝐹)‘((♯‘𝐹) − 1)) ∈ ℂ) |
22 | 21 | mul01d 10862 | . . . . . 6 ⊢ ((𝐹 ∈ (Word ℝ ∖ {∅}) ∧ (𝐹‘0) ≠ 0) → (((𝑇‘𝐹)‘((♯‘𝐹) − 1)) · 0) = 0) |
23 | 22 | breq1d 5035 | . . . . 5 ⊢ ((𝐹 ∈ (Word ℝ ∖ {∅}) ∧ (𝐹‘0) ≠ 0) → ((((𝑇‘𝐹)‘((♯‘𝐹) − 1)) · 0) < 0 ↔ 0 < 0)) |
24 | 8, 23 | mtbiri 331 | . . . 4 ⊢ ((𝐹 ∈ (Word ℝ ∖ {∅}) ∧ (𝐹‘0) ≠ 0) → ¬ (((𝑇‘𝐹)‘((♯‘𝐹) − 1)) · 0) < 0) |
25 | 24 | iffalsed 4424 | . . 3 ⊢ ((𝐹 ∈ (Word ℝ ∖ {∅}) ∧ (𝐹‘0) ≠ 0) → if((((𝑇‘𝐹)‘((♯‘𝐹) − 1)) · 0) < 0, 1, 0) = 0) |
26 | 25 | oveq2d 7159 | . 2 ⊢ ((𝐹 ∈ (Word ℝ ∖ {∅}) ∧ (𝐹‘0) ≠ 0) → ((𝑉‘𝐹) + if((((𝑇‘𝐹)‘((♯‘𝐹) − 1)) · 0) < 0, 1, 0)) = ((𝑉‘𝐹) + 0)) |
27 | 2, 3, 4, 5 | signsvvf 32062 | . . . . . 6 ⊢ 𝑉:Word ℝ⟶ℕ0 |
28 | 27 | a1i 11 | . . . . 5 ⊢ ((𝐹 ∈ (Word ℝ ∖ {∅}) ∧ (𝐹‘0) ≠ 0) → 𝑉:Word ℝ⟶ℕ0) |
29 | 13 | eldifad 3866 | . . . . 5 ⊢ ((𝐹 ∈ (Word ℝ ∖ {∅}) ∧ (𝐹‘0) ≠ 0) → 𝐹 ∈ Word ℝ) |
30 | 28, 29 | ffvelrnd 6836 | . . . 4 ⊢ ((𝐹 ∈ (Word ℝ ∖ {∅}) ∧ (𝐹‘0) ≠ 0) → (𝑉‘𝐹) ∈ ℕ0) |
31 | 30 | nn0cnd 11981 | . . 3 ⊢ ((𝐹 ∈ (Word ℝ ∖ {∅}) ∧ (𝐹‘0) ≠ 0) → (𝑉‘𝐹) ∈ ℂ) |
32 | 31 | addid1d 10863 | . 2 ⊢ ((𝐹 ∈ (Word ℝ ∖ {∅}) ∧ (𝐹‘0) ≠ 0) → ((𝑉‘𝐹) + 0) = (𝑉‘𝐹)) |
33 | 7, 26, 32 | 3eqtrd 2798 | 1 ⊢ ((𝐹 ∈ (Word ℝ ∖ {∅}) ∧ (𝐹‘0) ≠ 0) → (𝑉‘(𝐹 ++ 〈“0”〉)) = (𝑉‘𝐹)) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 400 = wceq 1539 ∈ wcel 2112 ≠ wne 2949 ∖ cdif 3851 ⊆ wss 3854 ∅c0 4221 ifcif 4413 {csn 4515 {cpr 4517 {ctp 4519 〈cop 4521 class class class wbr 5025 ↦ cmpt 5105 ⟶wf 6324 ‘cfv 6328 (class class class)co 7143 ∈ cmpo 7145 ℂcc 10558 ℝcr 10559 0cc0 10560 1c1 10561 + caddc 10563 · cmul 10565 < clt 10698 − cmin 10893 -cneg 10894 ℕcn 11659 ℕ0cn0 11919 ...cfz 12924 ..^cfzo 13067 ♯chash 13725 Word cword 13898 ++ cconcat 13954 〈“cs1 13981 sgncsgn 14478 Σcsu 15075 ndxcnx 16523 Basecbs 16526 +gcplusg 16608 Σg cgsu 16757 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1798 ax-4 1812 ax-5 1912 ax-6 1971 ax-7 2016 ax-8 2114 ax-9 2122 ax-10 2143 ax-11 2159 ax-12 2176 ax-ext 2730 ax-rep 5149 ax-sep 5162 ax-nul 5169 ax-pow 5227 ax-pr 5291 ax-un 7452 ax-inf2 9122 ax-cnex 10616 ax-resscn 10617 ax-1cn 10618 ax-icn 10619 ax-addcl 10620 ax-addrcl 10621 ax-mulcl 10622 ax-mulrcl 10623 ax-mulcom 10624 ax-addass 10625 ax-mulass 10626 ax-distr 10627 ax-i2m1 10628 ax-1ne0 10629 ax-1rid 10630 ax-rnegex 10631 ax-rrecex 10632 ax-cnre 10633 ax-pre-lttri 10634 ax-pre-lttrn 10635 ax-pre-ltadd 10636 ax-pre-mulgt0 10637 ax-pre-sup 10638 |
This theorem depends on definitions: df-bi 210 df-an 401 df-or 846 df-3or 1086 df-3an 1087 df-tru 1542 df-fal 1552 df-ex 1783 df-nf 1787 df-sb 2071 df-mo 2558 df-eu 2589 df-clab 2737 df-cleq 2751 df-clel 2831 df-nfc 2899 df-ne 2950 df-nel 3054 df-ral 3073 df-rex 3074 df-reu 3075 df-rmo 3076 df-rab 3077 df-v 3409 df-sbc 3694 df-csb 3802 df-dif 3857 df-un 3859 df-in 3861 df-ss 3871 df-pss 3873 df-nul 4222 df-if 4414 df-pw 4489 df-sn 4516 df-pr 4518 df-tp 4520 df-op 4522 df-uni 4792 df-int 4832 df-iun 4878 df-br 5026 df-opab 5088 df-mpt 5106 df-tr 5132 df-id 5423 df-eprel 5428 df-po 5436 df-so 5437 df-fr 5476 df-se 5477 df-we 5478 df-xp 5523 df-rel 5524 df-cnv 5525 df-co 5526 df-dm 5527 df-rn 5528 df-res 5529 df-ima 5530 df-pred 6119 df-ord 6165 df-on 6166 df-lim 6167 df-suc 6168 df-iota 6287 df-fun 6330 df-fn 6331 df-f 6332 df-f1 6333 df-fo 6334 df-f1o 6335 df-fv 6336 df-isom 6337 df-riota 7101 df-ov 7146 df-oprab 7147 df-mpo 7148 df-om 7573 df-1st 7686 df-2nd 7687 df-supp 7829 df-wrecs 7950 df-recs 8011 df-rdg 8049 df-1o 8105 df-oadd 8109 df-er 8292 df-en 8521 df-dom 8522 df-sdom 8523 df-fin 8524 df-sup 8924 df-oi 8992 df-card 9386 df-pnf 10700 df-mnf 10701 df-xr 10702 df-ltxr 10703 df-le 10704 df-sub 10895 df-neg 10896 df-div 11321 df-nn 11660 df-2 11722 df-3 11723 df-n0 11920 df-xnn0 11992 df-z 12006 df-uz 12268 df-rp 12416 df-fz 12925 df-fzo 13068 df-seq 13404 df-exp 13465 df-hash 13726 df-word 13899 df-lsw 13947 df-concat 13955 df-s1 13982 df-substr 14035 df-pfx 14065 df-sgn 14479 df-cj 14491 df-re 14492 df-im 14493 df-sqrt 14627 df-abs 14628 df-clim 14878 df-sum 15076 df-struct 16528 df-ndx 16529 df-slot 16530 df-base 16532 df-plusg 16621 df-0g 16758 df-gsum 16759 df-mgm 17903 df-sgrp 17952 df-mnd 17963 df-mulg 18277 df-cntz 18499 |
This theorem is referenced by: (None) |
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