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Mirrors > Home > MPE Home > Th. List > Mathboxes > blengt1fldiv2p1 | Structured version Visualization version GIF version |
Description: The binary length of an integer greater than 1 is the binary length of the integer divided by 2, increased by one. (Contributed by AV, 3-Jun-2020.) |
Ref | Expression |
---|---|
blengt1fldiv2p1 | ⊢ (𝑁 ∈ (ℤ≥‘2) → (#b‘𝑁) = ((#b‘(⌊‘(𝑁 / 2))) + 1)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | eluz2nn 12623 | . . 3 ⊢ (𝑁 ∈ (ℤ≥‘2) → 𝑁 ∈ ℕ) | |
2 | nneop 45841 | . . 3 ⊢ (𝑁 ∈ ℕ → ((𝑁 / 2) ∈ ℕ ∨ ((𝑁 + 1) / 2) ∈ ℕ)) | |
3 | 1, 2 | syl 17 | . 2 ⊢ (𝑁 ∈ (ℤ≥‘2) → ((𝑁 / 2) ∈ ℕ ∨ ((𝑁 + 1) / 2) ∈ ℕ)) |
4 | nnnn0 12240 | . . . . . . . . 9 ⊢ ((𝑁 / 2) ∈ ℕ → (𝑁 / 2) ∈ ℕ0) | |
5 | blennn0em1 45906 | . . . . . . . . 9 ⊢ ((𝑁 ∈ ℕ ∧ (𝑁 / 2) ∈ ℕ0) → (#b‘(𝑁 / 2)) = ((#b‘𝑁) − 1)) | |
6 | 4, 5 | sylan2 593 | . . . . . . . 8 ⊢ ((𝑁 ∈ ℕ ∧ (𝑁 / 2) ∈ ℕ) → (#b‘(𝑁 / 2)) = ((#b‘𝑁) − 1)) |
7 | 6 | ancoms 459 | . . . . . . 7 ⊢ (((𝑁 / 2) ∈ ℕ ∧ 𝑁 ∈ ℕ) → (#b‘(𝑁 / 2)) = ((#b‘𝑁) − 1)) |
8 | 7 | oveq1d 7286 | . . . . . 6 ⊢ (((𝑁 / 2) ∈ ℕ ∧ 𝑁 ∈ ℕ) → ((#b‘(𝑁 / 2)) + 1) = (((#b‘𝑁) − 1) + 1)) |
9 | nnz 12342 | . . . . . . . . . . 11 ⊢ ((𝑁 / 2) ∈ ℕ → (𝑁 / 2) ∈ ℤ) | |
10 | flid 13526 | . . . . . . . . . . 11 ⊢ ((𝑁 / 2) ∈ ℤ → (⌊‘(𝑁 / 2)) = (𝑁 / 2)) | |
11 | 9, 10 | syl 17 | . . . . . . . . . 10 ⊢ ((𝑁 / 2) ∈ ℕ → (⌊‘(𝑁 / 2)) = (𝑁 / 2)) |
12 | 11 | eqcomd 2746 | . . . . . . . . 9 ⊢ ((𝑁 / 2) ∈ ℕ → (𝑁 / 2) = (⌊‘(𝑁 / 2))) |
13 | 12 | fveq2d 6775 | . . . . . . . 8 ⊢ ((𝑁 / 2) ∈ ℕ → (#b‘(𝑁 / 2)) = (#b‘(⌊‘(𝑁 / 2)))) |
14 | 13 | oveq1d 7286 | . . . . . . 7 ⊢ ((𝑁 / 2) ∈ ℕ → ((#b‘(𝑁 / 2)) + 1) = ((#b‘(⌊‘(𝑁 / 2))) + 1)) |
15 | 14 | adantr 481 | . . . . . 6 ⊢ (((𝑁 / 2) ∈ ℕ ∧ 𝑁 ∈ ℕ) → ((#b‘(𝑁 / 2)) + 1) = ((#b‘(⌊‘(𝑁 / 2))) + 1)) |
16 | blennnelnn 45891 | . . . . . . . . 9 ⊢ (𝑁 ∈ ℕ → (#b‘𝑁) ∈ ℕ) | |
17 | 16 | nncnd 11989 | . . . . . . . 8 ⊢ (𝑁 ∈ ℕ → (#b‘𝑁) ∈ ℂ) |
18 | npcan1 11400 | . . . . . . . 8 ⊢ ((#b‘𝑁) ∈ ℂ → (((#b‘𝑁) − 1) + 1) = (#b‘𝑁)) | |
19 | 17, 18 | syl 17 | . . . . . . 7 ⊢ (𝑁 ∈ ℕ → (((#b‘𝑁) − 1) + 1) = (#b‘𝑁)) |
20 | 19 | adantl 482 | . . . . . 6 ⊢ (((𝑁 / 2) ∈ ℕ ∧ 𝑁 ∈ ℕ) → (((#b‘𝑁) − 1) + 1) = (#b‘𝑁)) |
21 | 8, 15, 20 | 3eqtr3rd 2789 | . . . . 5 ⊢ (((𝑁 / 2) ∈ ℕ ∧ 𝑁 ∈ ℕ) → (#b‘𝑁) = ((#b‘(⌊‘(𝑁 / 2))) + 1)) |
22 | 21 | expcom 414 | . . . 4 ⊢ (𝑁 ∈ ℕ → ((𝑁 / 2) ∈ ℕ → (#b‘𝑁) = ((#b‘(⌊‘(𝑁 / 2))) + 1))) |
23 | 22, 1 | syl11 33 | . . 3 ⊢ ((𝑁 / 2) ∈ ℕ → (𝑁 ∈ (ℤ≥‘2) → (#b‘𝑁) = ((#b‘(⌊‘(𝑁 / 2))) + 1))) |
24 | nnnn0 12240 | . . . . . . 7 ⊢ (((𝑁 + 1) / 2) ∈ ℕ → ((𝑁 + 1) / 2) ∈ ℕ0) | |
25 | blennngt2o2 45907 | . . . . . . 7 ⊢ ((𝑁 ∈ (ℤ≥‘2) ∧ ((𝑁 + 1) / 2) ∈ ℕ0) → (#b‘𝑁) = ((#b‘((𝑁 − 1) / 2)) + 1)) | |
26 | 24, 25 | sylan2 593 | . . . . . 6 ⊢ ((𝑁 ∈ (ℤ≥‘2) ∧ ((𝑁 + 1) / 2) ∈ ℕ) → (#b‘𝑁) = ((#b‘((𝑁 − 1) / 2)) + 1)) |
27 | 26 | ancoms 459 | . . . . 5 ⊢ ((((𝑁 + 1) / 2) ∈ ℕ ∧ 𝑁 ∈ (ℤ≥‘2)) → (#b‘𝑁) = ((#b‘((𝑁 − 1) / 2)) + 1)) |
28 | eluzge2nn0 12626 | . . . . . . . . 9 ⊢ (𝑁 ∈ (ℤ≥‘2) → 𝑁 ∈ ℕ0) | |
29 | nn0ofldiv2 45847 | . . . . . . . . 9 ⊢ ((𝑁 ∈ ℕ0 ∧ ((𝑁 + 1) / 2) ∈ ℕ0) → (⌊‘(𝑁 / 2)) = ((𝑁 − 1) / 2)) | |
30 | 28, 24, 29 | syl2anr 597 | . . . . . . . 8 ⊢ ((((𝑁 + 1) / 2) ∈ ℕ ∧ 𝑁 ∈ (ℤ≥‘2)) → (⌊‘(𝑁 / 2)) = ((𝑁 − 1) / 2)) |
31 | 30 | eqcomd 2746 | . . . . . . 7 ⊢ ((((𝑁 + 1) / 2) ∈ ℕ ∧ 𝑁 ∈ (ℤ≥‘2)) → ((𝑁 − 1) / 2) = (⌊‘(𝑁 / 2))) |
32 | 31 | fveq2d 6775 | . . . . . 6 ⊢ ((((𝑁 + 1) / 2) ∈ ℕ ∧ 𝑁 ∈ (ℤ≥‘2)) → (#b‘((𝑁 − 1) / 2)) = (#b‘(⌊‘(𝑁 / 2)))) |
33 | 32 | oveq1d 7286 | . . . . 5 ⊢ ((((𝑁 + 1) / 2) ∈ ℕ ∧ 𝑁 ∈ (ℤ≥‘2)) → ((#b‘((𝑁 − 1) / 2)) + 1) = ((#b‘(⌊‘(𝑁 / 2))) + 1)) |
34 | 27, 33 | eqtrd 2780 | . . . 4 ⊢ ((((𝑁 + 1) / 2) ∈ ℕ ∧ 𝑁 ∈ (ℤ≥‘2)) → (#b‘𝑁) = ((#b‘(⌊‘(𝑁 / 2))) + 1)) |
35 | 34 | ex 413 | . . 3 ⊢ (((𝑁 + 1) / 2) ∈ ℕ → (𝑁 ∈ (ℤ≥‘2) → (#b‘𝑁) = ((#b‘(⌊‘(𝑁 / 2))) + 1))) |
36 | 23, 35 | jaoi 854 | . 2 ⊢ (((𝑁 / 2) ∈ ℕ ∨ ((𝑁 + 1) / 2) ∈ ℕ) → (𝑁 ∈ (ℤ≥‘2) → (#b‘𝑁) = ((#b‘(⌊‘(𝑁 / 2))) + 1))) |
37 | 3, 36 | mpcom 38 | 1 ⊢ (𝑁 ∈ (ℤ≥‘2) → (#b‘𝑁) = ((#b‘(⌊‘(𝑁 / 2))) + 1)) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 396 ∨ wo 844 = wceq 1542 ∈ wcel 2110 ‘cfv 6432 (class class class)co 7271 ℂcc 10870 1c1 10873 + caddc 10875 − cmin 11205 / cdiv 11632 ℕcn 11973 2c2 12028 ℕ0cn0 12233 ℤcz 12319 ℤ≥cuz 12581 ⌊cfl 13508 #bcblen 45884 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1802 ax-4 1816 ax-5 1917 ax-6 1975 ax-7 2015 ax-8 2112 ax-9 2120 ax-10 2141 ax-11 2158 ax-12 2175 ax-ext 2711 ax-rep 5214 ax-sep 5227 ax-nul 5234 ax-pow 5292 ax-pr 5356 ax-un 7582 ax-inf2 9377 ax-cnex 10928 ax-resscn 10929 ax-1cn 10930 ax-icn 10931 ax-addcl 10932 ax-addrcl 10933 ax-mulcl 10934 ax-mulrcl 10935 ax-mulcom 10936 ax-addass 10937 ax-mulass 10938 ax-distr 10939 ax-i2m1 10940 ax-1ne0 10941 ax-1rid 10942 ax-rnegex 10943 ax-rrecex 10944 ax-cnre 10945 ax-pre-lttri 10946 ax-pre-lttrn 10947 ax-pre-ltadd 10948 ax-pre-mulgt0 10949 ax-pre-sup 10950 ax-addf 10951 ax-mulf 10952 |
This theorem depends on definitions: df-bi 206 df-an 397 df-or 845 df-3or 1087 df-3an 1088 df-tru 1545 df-fal 1555 df-ex 1787 df-nf 1791 df-sb 2072 df-mo 2542 df-eu 2571 df-clab 2718 df-cleq 2732 df-clel 2818 df-nfc 2891 df-ne 2946 df-nel 3052 df-ral 3071 df-rex 3072 df-reu 3073 df-rmo 3074 df-rab 3075 df-v 3433 df-sbc 3721 df-csb 3838 df-dif 3895 df-un 3897 df-in 3899 df-ss 3909 df-pss 3911 df-nul 4263 df-if 4466 df-pw 4541 df-sn 4568 df-pr 4570 df-tp 4572 df-op 4574 df-uni 4846 df-int 4886 df-iun 4932 df-iin 4933 df-br 5080 df-opab 5142 df-mpt 5163 df-tr 5197 df-id 5490 df-eprel 5496 df-po 5504 df-so 5505 df-fr 5545 df-se 5546 df-we 5547 df-xp 5596 df-rel 5597 df-cnv 5598 df-co 5599 df-dm 5600 df-rn 5601 df-res 5602 df-ima 5603 df-pred 6201 df-ord 6268 df-on 6269 df-lim 6270 df-suc 6271 df-iota 6390 df-fun 6434 df-fn 6435 df-f 6436 df-f1 6437 df-fo 6438 df-f1o 6439 df-fv 6440 df-isom 6441 df-riota 7228 df-ov 7274 df-oprab 7275 df-mpo 7276 df-of 7527 df-om 7707 df-1st 7824 df-2nd 7825 df-supp 7969 df-frecs 8088 df-wrecs 8119 df-recs 8193 df-rdg 8232 df-1o 8288 df-2o 8289 df-er 8481 df-map 8600 df-pm 8601 df-ixp 8669 df-en 8717 df-dom 8718 df-sdom 8719 df-fin 8720 df-fsupp 9107 df-fi 9148 df-sup 9179 df-inf 9180 df-oi 9247 df-card 9698 df-pnf 11012 df-mnf 11013 df-xr 11014 df-ltxr 11015 df-le 11016 df-sub 11207 df-neg 11208 df-div 11633 df-nn 11974 df-2 12036 df-3 12037 df-4 12038 df-5 12039 df-6 12040 df-7 12041 df-8 12042 df-9 12043 df-n0 12234 df-z 12320 df-dec 12437 df-uz 12582 df-q 12688 df-rp 12730 df-xneg 12847 df-xadd 12848 df-xmul 12849 df-ioo 13082 df-ioc 13083 df-ico 13084 df-icc 13085 df-fz 13239 df-fzo 13382 df-fl 13510 df-mod 13588 df-seq 13720 df-exp 13781 df-fac 13986 df-bc 14015 df-hash 14043 df-shft 14776 df-cj 14808 df-re 14809 df-im 14810 df-sqrt 14944 df-abs 14945 df-limsup 15178 df-clim 15195 df-rlim 15196 df-sum 15396 df-ef 15775 df-sin 15777 df-cos 15778 df-pi 15780 df-struct 16846 df-sets 16863 df-slot 16881 df-ndx 16893 df-base 16911 df-ress 16940 df-plusg 16973 df-mulr 16974 df-starv 16975 df-sca 16976 df-vsca 16977 df-ip 16978 df-tset 16979 df-ple 16980 df-ds 16982 df-unif 16983 df-hom 16984 df-cco 16985 df-rest 17131 df-topn 17132 df-0g 17150 df-gsum 17151 df-topgen 17152 df-pt 17153 df-prds 17156 df-xrs 17211 df-qtop 17216 df-imas 17217 df-xps 17219 df-mre 17293 df-mrc 17294 df-acs 17296 df-mgm 18324 df-sgrp 18373 df-mnd 18384 df-submnd 18429 df-mulg 18699 df-cntz 18921 df-cmn 19386 df-psmet 20587 df-xmet 20588 df-met 20589 df-bl 20590 df-mopn 20591 df-fbas 20592 df-fg 20593 df-cnfld 20596 df-top 22041 df-topon 22058 df-topsp 22080 df-bases 22094 df-cld 22168 df-ntr 22169 df-cls 22170 df-nei 22247 df-lp 22285 df-perf 22286 df-cn 22376 df-cnp 22377 df-haus 22464 df-tx 22711 df-hmeo 22904 df-fil 22995 df-fm 23087 df-flim 23088 df-flf 23089 df-xms 23471 df-ms 23472 df-tms 23473 df-cncf 24039 df-limc 25028 df-dv 25029 df-log 25710 df-cxp 25711 df-logb 25913 df-blen 45885 |
This theorem is referenced by: (None) |
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