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Mirrors > Home > MPE Home > Th. List > Mathboxes > blennn0em1 | Structured version Visualization version GIF version |
Description: The binary length of the half of an even positive integer is the binary length of the integer minus 1. (Contributed by AV, 30-May-2010.) |
Ref | Expression |
---|---|
blennn0em1 | ⊢ ((𝑁 ∈ ℕ ∧ (𝑁 / 2) ∈ ℕ0) → (#b‘(𝑁 / 2)) = ((#b‘𝑁) − 1)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | nncn 11358 | . . . . . . . 8 ⊢ (𝑁 ∈ ℕ → 𝑁 ∈ ℂ) | |
2 | 2cnd 11428 | . . . . . . . 8 ⊢ (𝑁 ∈ ℕ → 2 ∈ ℂ) | |
3 | 2ne0 11461 | . . . . . . . . 9 ⊢ 2 ≠ 0 | |
4 | 3 | a1i 11 | . . . . . . . 8 ⊢ (𝑁 ∈ ℕ → 2 ≠ 0) |
5 | 1, 2, 4 | 3jca 1164 | . . . . . . 7 ⊢ (𝑁 ∈ ℕ → (𝑁 ∈ ℂ ∧ 2 ∈ ℂ ∧ 2 ≠ 0)) |
6 | 5 | adantr 474 | . . . . . 6 ⊢ ((𝑁 ∈ ℕ ∧ (𝑁 / 2) ∈ ℕ0) → (𝑁 ∈ ℂ ∧ 2 ∈ ℂ ∧ 2 ≠ 0)) |
7 | divcan2 11017 | . . . . . . 7 ⊢ ((𝑁 ∈ ℂ ∧ 2 ∈ ℂ ∧ 2 ≠ 0) → (2 · (𝑁 / 2)) = 𝑁) | |
8 | 7 | eqcomd 2830 | . . . . . 6 ⊢ ((𝑁 ∈ ℂ ∧ 2 ∈ ℂ ∧ 2 ≠ 0) → 𝑁 = (2 · (𝑁 / 2))) |
9 | 6, 8 | syl 17 | . . . . 5 ⊢ ((𝑁 ∈ ℕ ∧ (𝑁 / 2) ∈ ℕ0) → 𝑁 = (2 · (𝑁 / 2))) |
10 | 9 | fveq2d 6436 | . . . 4 ⊢ ((𝑁 ∈ ℕ ∧ (𝑁 / 2) ∈ ℕ0) → (#b‘𝑁) = (#b‘(2 · (𝑁 / 2)))) |
11 | nn0enne 15467 | . . . . . 6 ⊢ (𝑁 ∈ ℕ → ((𝑁 / 2) ∈ ℕ0 ↔ (𝑁 / 2) ∈ ℕ)) | |
12 | 11 | biimpa 470 | . . . . 5 ⊢ ((𝑁 ∈ ℕ ∧ (𝑁 / 2) ∈ ℕ0) → (𝑁 / 2) ∈ ℕ) |
13 | blennnt2 43229 | . . . . 5 ⊢ ((𝑁 / 2) ∈ ℕ → (#b‘(2 · (𝑁 / 2))) = ((#b‘(𝑁 / 2)) + 1)) | |
14 | 12, 13 | syl 17 | . . . 4 ⊢ ((𝑁 ∈ ℕ ∧ (𝑁 / 2) ∈ ℕ0) → (#b‘(2 · (𝑁 / 2))) = ((#b‘(𝑁 / 2)) + 1)) |
15 | 10, 14 | eqtr2d 2861 | . . 3 ⊢ ((𝑁 ∈ ℕ ∧ (𝑁 / 2) ∈ ℕ0) → ((#b‘(𝑁 / 2)) + 1) = (#b‘𝑁)) |
16 | blennnelnn 43216 | . . . . . 6 ⊢ (𝑁 ∈ ℕ → (#b‘𝑁) ∈ ℕ) | |
17 | 16 | nncnd 11367 | . . . . 5 ⊢ (𝑁 ∈ ℕ → (#b‘𝑁) ∈ ℂ) |
18 | 17 | adantr 474 | . . . 4 ⊢ ((𝑁 ∈ ℕ ∧ (𝑁 / 2) ∈ ℕ0) → (#b‘𝑁) ∈ ℂ) |
19 | 1cnd 10350 | . . . 4 ⊢ ((𝑁 ∈ ℕ ∧ (𝑁 / 2) ∈ ℕ0) → 1 ∈ ℂ) | |
20 | blennn0elnn 43217 | . . . . . 6 ⊢ ((𝑁 / 2) ∈ ℕ0 → (#b‘(𝑁 / 2)) ∈ ℕ) | |
21 | 20 | nncnd 11367 | . . . . 5 ⊢ ((𝑁 / 2) ∈ ℕ0 → (#b‘(𝑁 / 2)) ∈ ℂ) |
22 | 21 | adantl 475 | . . . 4 ⊢ ((𝑁 ∈ ℕ ∧ (𝑁 / 2) ∈ ℕ0) → (#b‘(𝑁 / 2)) ∈ ℂ) |
23 | 18, 19, 22 | subadd2d 10731 | . . 3 ⊢ ((𝑁 ∈ ℕ ∧ (𝑁 / 2) ∈ ℕ0) → (((#b‘𝑁) − 1) = (#b‘(𝑁 / 2)) ↔ ((#b‘(𝑁 / 2)) + 1) = (#b‘𝑁))) |
24 | 15, 23 | mpbird 249 | . 2 ⊢ ((𝑁 ∈ ℕ ∧ (𝑁 / 2) ∈ ℕ0) → ((#b‘𝑁) − 1) = (#b‘(𝑁 / 2))) |
25 | 24 | eqcomd 2830 | 1 ⊢ ((𝑁 ∈ ℕ ∧ (𝑁 / 2) ∈ ℕ0) → (#b‘(𝑁 / 2)) = ((#b‘𝑁) − 1)) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 386 ∧ w3a 1113 = wceq 1658 ∈ wcel 2166 ≠ wne 2998 ‘cfv 6122 (class class class)co 6904 ℂcc 10249 0cc0 10251 1c1 10252 + caddc 10254 · cmul 10256 − cmin 10584 / cdiv 11008 ℕcn 11349 2c2 11405 ℕ0cn0 11617 #bcblen 43209 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1896 ax-4 1910 ax-5 2011 ax-6 2077 ax-7 2114 ax-8 2168 ax-9 2175 ax-10 2194 ax-11 2209 ax-12 2222 ax-13 2390 ax-ext 2802 ax-rep 4993 ax-sep 5004 ax-nul 5012 ax-pow 5064 ax-pr 5126 ax-un 7208 ax-inf2 8814 ax-cnex 10307 ax-resscn 10308 ax-1cn 10309 ax-icn 10310 ax-addcl 10311 ax-addrcl 10312 ax-mulcl 10313 ax-mulrcl 10314 ax-mulcom 10315 ax-addass 10316 ax-mulass 10317 ax-distr 10318 ax-i2m1 10319 ax-1ne0 10320 ax-1rid 10321 ax-rnegex 10322 ax-rrecex 10323 ax-cnre 10324 ax-pre-lttri 10325 ax-pre-lttrn 10326 ax-pre-ltadd 10327 ax-pre-mulgt0 10328 ax-pre-sup 10329 ax-addf 10330 ax-mulf 10331 |
This theorem depends on definitions: df-bi 199 df-an 387 df-or 881 df-3or 1114 df-3an 1115 df-tru 1662 df-fal 1672 df-ex 1881 df-nf 1885 df-sb 2070 df-mo 2604 df-eu 2639 df-clab 2811 df-cleq 2817 df-clel 2820 df-nfc 2957 df-ne 2999 df-nel 3102 df-ral 3121 df-rex 3122 df-reu 3123 df-rmo 3124 df-rab 3125 df-v 3415 df-sbc 3662 df-csb 3757 df-dif 3800 df-un 3802 df-in 3804 df-ss 3811 df-pss 3813 df-nul 4144 df-if 4306 df-pw 4379 df-sn 4397 df-pr 4399 df-tp 4401 df-op 4403 df-uni 4658 df-int 4697 df-iun 4741 df-iin 4742 df-br 4873 df-opab 4935 df-mpt 4952 df-tr 4975 df-id 5249 df-eprel 5254 df-po 5262 df-so 5263 df-fr 5300 df-se 5301 df-we 5302 df-xp 5347 df-rel 5348 df-cnv 5349 df-co 5350 df-dm 5351 df-rn 5352 df-res 5353 df-ima 5354 df-pred 5919 df-ord 5965 df-on 5966 df-lim 5967 df-suc 5968 df-iota 6085 df-fun 6124 df-fn 6125 df-f 6126 df-f1 6127 df-fo 6128 df-f1o 6129 df-fv 6130 df-isom 6131 df-riota 6865 df-ov 6907 df-oprab 6908 df-mpt2 6909 df-of 7156 df-om 7326 df-1st 7427 df-2nd 7428 df-supp 7559 df-wrecs 7671 df-recs 7733 df-rdg 7771 df-1o 7825 df-2o 7826 df-oadd 7829 df-er 8008 df-map 8123 df-pm 8124 df-ixp 8175 df-en 8222 df-dom 8223 df-sdom 8224 df-fin 8225 df-fsupp 8544 df-fi 8585 df-sup 8616 df-inf 8617 df-oi 8683 df-card 9077 df-cda 9304 df-pnf 10392 df-mnf 10393 df-xr 10394 df-ltxr 10395 df-le 10396 df-sub 10586 df-neg 10587 df-div 11009 df-nn 11350 df-2 11413 df-3 11414 df-4 11415 df-5 11416 df-6 11417 df-7 11418 df-8 11419 df-9 11420 df-n0 11618 df-z 11704 df-dec 11821 df-uz 11968 df-q 12071 df-rp 12112 df-xneg 12231 df-xadd 12232 df-xmul 12233 df-ioo 12466 df-ioc 12467 df-ico 12468 df-icc 12469 df-fz 12619 df-fzo 12760 df-fl 12887 df-mod 12963 df-seq 13095 df-exp 13154 df-fac 13353 df-bc 13382 df-hash 13410 df-shft 14183 df-cj 14215 df-re 14216 df-im 14217 df-sqrt 14351 df-abs 14352 df-limsup 14578 df-clim 14595 df-rlim 14596 df-sum 14793 df-ef 15169 df-sin 15171 df-cos 15172 df-pi 15174 df-struct 16223 df-ndx 16224 df-slot 16225 df-base 16227 df-sets 16228 df-ress 16229 df-plusg 16317 df-mulr 16318 df-starv 16319 df-sca 16320 df-vsca 16321 df-ip 16322 df-tset 16323 df-ple 16324 df-ds 16326 df-unif 16327 df-hom 16328 df-cco 16329 df-rest 16435 df-topn 16436 df-0g 16454 df-gsum 16455 df-topgen 16456 df-pt 16457 df-prds 16460 df-xrs 16514 df-qtop 16519 df-imas 16520 df-xps 16522 df-mre 16598 df-mrc 16599 df-acs 16601 df-mgm 17594 df-sgrp 17636 df-mnd 17647 df-submnd 17688 df-mulg 17894 df-cntz 18099 df-cmn 18547 df-psmet 20097 df-xmet 20098 df-met 20099 df-bl 20100 df-mopn 20101 df-fbas 20102 df-fg 20103 df-cnfld 20106 df-top 21068 df-topon 21085 df-topsp 21107 df-bases 21120 df-cld 21193 df-ntr 21194 df-cls 21195 df-nei 21272 df-lp 21310 df-perf 21311 df-cn 21401 df-cnp 21402 df-haus 21489 df-tx 21735 df-hmeo 21928 df-fil 22019 df-fm 22111 df-flim 22112 df-flf 22113 df-xms 22494 df-ms 22495 df-tms 22496 df-cncf 23050 df-limc 24028 df-dv 24029 df-log 24701 df-logb 24904 df-blen 43210 |
This theorem is referenced by: blengt1fldiv2p1 43233 nn0sumshdiglemA 43259 |
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