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| Mirrors > Home > MPE Home > Th. List > relogbcxpb | Structured version Visualization version GIF version | ||
| Description: The logarithm is the inverse of the exponentiation. Observation in [Cohen4] p. 348. (Contributed by AV, 11-Jun-2020.) |
| Ref | Expression |
|---|---|
| relogbcxpb | ⊢ (((𝐵 ∈ ℝ+ ∧ 𝐵 ≠ 1) ∧ 𝑋 ∈ ℝ+ ∧ 𝑌 ∈ ℝ) → ((𝐵 logb 𝑋) = 𝑌 ↔ (𝐵↑𝑐𝑌) = 𝑋)) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | oveq2 7421 | . . . 4 ⊢ (𝑌 = (𝐵 logb 𝑋) → (𝐵↑𝑐𝑌) = (𝐵↑𝑐(𝐵 logb 𝑋))) | |
| 2 | 1 | eqcoms 2742 | . . 3 ⊢ ((𝐵 logb 𝑋) = 𝑌 → (𝐵↑𝑐𝑌) = (𝐵↑𝑐(𝐵 logb 𝑋))) |
| 3 | rpcn 13027 | . . . . . . . 8 ⊢ (𝐵 ∈ ℝ+ → 𝐵 ∈ ℂ) | |
| 4 | 3 | adantr 480 | . . . . . . 7 ⊢ ((𝐵 ∈ ℝ+ ∧ 𝐵 ≠ 1) → 𝐵 ∈ ℂ) |
| 5 | rpne0 13033 | . . . . . . . 8 ⊢ (𝐵 ∈ ℝ+ → 𝐵 ≠ 0) | |
| 6 | 5 | adantr 480 | . . . . . . 7 ⊢ ((𝐵 ∈ ℝ+ ∧ 𝐵 ≠ 1) → 𝐵 ≠ 0) |
| 7 | simpr 484 | . . . . . . 7 ⊢ ((𝐵 ∈ ℝ+ ∧ 𝐵 ≠ 1) → 𝐵 ≠ 1) | |
| 8 | eldifpr 4638 | . . . . . . 7 ⊢ (𝐵 ∈ (ℂ ∖ {0, 1}) ↔ (𝐵 ∈ ℂ ∧ 𝐵 ≠ 0 ∧ 𝐵 ≠ 1)) | |
| 9 | 4, 6, 7, 8 | syl3anbrc 1343 | . . . . . 6 ⊢ ((𝐵 ∈ ℝ+ ∧ 𝐵 ≠ 1) → 𝐵 ∈ (ℂ ∖ {0, 1})) |
| 10 | rpcndif0 13036 | . . . . . 6 ⊢ (𝑋 ∈ ℝ+ → 𝑋 ∈ (ℂ ∖ {0})) | |
| 11 | 9, 10 | anim12i 613 | . . . . 5 ⊢ (((𝐵 ∈ ℝ+ ∧ 𝐵 ≠ 1) ∧ 𝑋 ∈ ℝ+) → (𝐵 ∈ (ℂ ∖ {0, 1}) ∧ 𝑋 ∈ (ℂ ∖ {0}))) |
| 12 | 11 | 3adant3 1132 | . . . 4 ⊢ (((𝐵 ∈ ℝ+ ∧ 𝐵 ≠ 1) ∧ 𝑋 ∈ ℝ+ ∧ 𝑌 ∈ ℝ) → (𝐵 ∈ (ℂ ∖ {0, 1}) ∧ 𝑋 ∈ (ℂ ∖ {0}))) |
| 13 | cxplogb 26766 | . . . 4 ⊢ ((𝐵 ∈ (ℂ ∖ {0, 1}) ∧ 𝑋 ∈ (ℂ ∖ {0})) → (𝐵↑𝑐(𝐵 logb 𝑋)) = 𝑋) | |
| 14 | 12, 13 | syl 17 | . . 3 ⊢ (((𝐵 ∈ ℝ+ ∧ 𝐵 ≠ 1) ∧ 𝑋 ∈ ℝ+ ∧ 𝑌 ∈ ℝ) → (𝐵↑𝑐(𝐵 logb 𝑋)) = 𝑋) |
| 15 | 2, 14 | sylan9eqr 2791 | . 2 ⊢ ((((𝐵 ∈ ℝ+ ∧ 𝐵 ≠ 1) ∧ 𝑋 ∈ ℝ+ ∧ 𝑌 ∈ ℝ) ∧ (𝐵 logb 𝑋) = 𝑌) → (𝐵↑𝑐𝑌) = 𝑋) |
| 16 | oveq2 7421 | . . . 4 ⊢ (𝑋 = (𝐵↑𝑐𝑌) → (𝐵 logb 𝑋) = (𝐵 logb (𝐵↑𝑐𝑌))) | |
| 17 | 16 | eqcoms 2742 | . . 3 ⊢ ((𝐵↑𝑐𝑌) = 𝑋 → (𝐵 logb 𝑋) = (𝐵 logb (𝐵↑𝑐𝑌))) |
| 18 | eldifsn 4766 | . . . . . . 7 ⊢ (𝐵 ∈ (ℝ+ ∖ {1}) ↔ (𝐵 ∈ ℝ+ ∧ 𝐵 ≠ 1)) | |
| 19 | 18 | biimpri 228 | . . . . . 6 ⊢ ((𝐵 ∈ ℝ+ ∧ 𝐵 ≠ 1) → 𝐵 ∈ (ℝ+ ∖ {1})) |
| 20 | 19 | anim1i 615 | . . . . 5 ⊢ (((𝐵 ∈ ℝ+ ∧ 𝐵 ≠ 1) ∧ 𝑌 ∈ ℝ) → (𝐵 ∈ (ℝ+ ∖ {1}) ∧ 𝑌 ∈ ℝ)) |
| 21 | 20 | 3adant2 1131 | . . . 4 ⊢ (((𝐵 ∈ ℝ+ ∧ 𝐵 ≠ 1) ∧ 𝑋 ∈ ℝ+ ∧ 𝑌 ∈ ℝ) → (𝐵 ∈ (ℝ+ ∖ {1}) ∧ 𝑌 ∈ ℝ)) |
| 22 | relogbcxp 26765 | . . . 4 ⊢ ((𝐵 ∈ (ℝ+ ∖ {1}) ∧ 𝑌 ∈ ℝ) → (𝐵 logb (𝐵↑𝑐𝑌)) = 𝑌) | |
| 23 | 21, 22 | syl 17 | . . 3 ⊢ (((𝐵 ∈ ℝ+ ∧ 𝐵 ≠ 1) ∧ 𝑋 ∈ ℝ+ ∧ 𝑌 ∈ ℝ) → (𝐵 logb (𝐵↑𝑐𝑌)) = 𝑌) |
| 24 | 17, 23 | sylan9eqr 2791 | . 2 ⊢ ((((𝐵 ∈ ℝ+ ∧ 𝐵 ≠ 1) ∧ 𝑋 ∈ ℝ+ ∧ 𝑌 ∈ ℝ) ∧ (𝐵↑𝑐𝑌) = 𝑋) → (𝐵 logb 𝑋) = 𝑌) |
| 25 | 15, 24 | impbida 800 | 1 ⊢ (((𝐵 ∈ ℝ+ ∧ 𝐵 ≠ 1) ∧ 𝑋 ∈ ℝ+ ∧ 𝑌 ∈ ℝ) → ((𝐵 logb 𝑋) = 𝑌 ↔ (𝐵↑𝑐𝑌) = 𝑋)) |
| Colors of variables: wff setvar class |
| Syntax hints: → wi 4 ↔ wb 206 ∧ wa 395 ∧ w3a 1086 = wceq 1539 ∈ wcel 2107 ≠ wne 2931 ∖ cdif 3928 {csn 4606 {cpr 4608 (class class class)co 7413 ℂcc 11135 ℝcr 11136 0cc0 11137 1c1 11138 ℝ+crp 13016 ↑𝑐ccxp 26534 logb clogb 26744 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1794 ax-4 1808 ax-5 1909 ax-6 1966 ax-7 2006 ax-8 2109 ax-9 2117 ax-10 2140 ax-11 2156 ax-12 2176 ax-ext 2706 ax-rep 5259 ax-sep 5276 ax-nul 5286 ax-pow 5345 ax-pr 5412 ax-un 7737 ax-inf2 9663 ax-cnex 11193 ax-resscn 11194 ax-1cn 11195 ax-icn 11196 ax-addcl 11197 ax-addrcl 11198 ax-mulcl 11199 ax-mulrcl 11200 ax-mulcom 11201 ax-addass 11202 ax-mulass 11203 ax-distr 11204 ax-i2m1 11205 ax-1ne0 11206 ax-1rid 11207 ax-rnegex 11208 ax-rrecex 11209 ax-cnre 11210 ax-pre-lttri 11211 ax-pre-lttrn 11212 ax-pre-ltadd 11213 ax-pre-mulgt0 11214 ax-pre-sup 11215 ax-addf 11216 |
| This theorem depends on definitions: df-bi 207 df-an 396 df-or 848 df-3or 1087 df-3an 1088 df-tru 1542 df-fal 1552 df-ex 1779 df-nf 1783 df-sb 2064 df-mo 2538 df-eu 2567 df-clab 2713 df-cleq 2726 df-clel 2808 df-nfc 2884 df-ne 2932 df-nel 3036 df-ral 3051 df-rex 3060 df-rmo 3363 df-reu 3364 df-rab 3420 df-v 3465 df-sbc 3771 df-csb 3880 df-dif 3934 df-un 3936 df-in 3938 df-ss 3948 df-pss 3951 df-nul 4314 df-if 4506 df-pw 4582 df-sn 4607 df-pr 4609 df-tp 4611 df-op 4613 df-uni 4888 df-int 4927 df-iun 4973 df-iin 4974 df-br 5124 df-opab 5186 df-mpt 5206 df-tr 5240 df-id 5558 df-eprel 5564 df-po 5572 df-so 5573 df-fr 5617 df-se 5618 df-we 5619 df-xp 5671 df-rel 5672 df-cnv 5673 df-co 5674 df-dm 5675 df-rn 5676 df-res 5677 df-ima 5678 df-pred 6301 df-ord 6366 df-on 6367 df-lim 6368 df-suc 6369 df-iota 6494 df-fun 6543 df-fn 6544 df-f 6545 df-f1 6546 df-fo 6547 df-f1o 6548 df-fv 6549 df-isom 6550 df-riota 7370 df-ov 7416 df-oprab 7417 df-mpo 7418 df-of 7679 df-om 7870 df-1st 7996 df-2nd 7997 df-supp 8168 df-frecs 8288 df-wrecs 8319 df-recs 8393 df-rdg 8432 df-1o 8488 df-2o 8489 df-er 8727 df-map 8850 df-pm 8851 df-ixp 8920 df-en 8968 df-dom 8969 df-sdom 8970 df-fin 8971 df-fsupp 9384 df-fi 9433 df-sup 9464 df-inf 9465 df-oi 9532 df-card 9961 df-pnf 11279 df-mnf 11280 df-xr 11281 df-ltxr 11282 df-le 11283 df-sub 11476 df-neg 11477 df-div 11903 df-nn 12249 df-2 12311 df-3 12312 df-4 12313 df-5 12314 df-6 12315 df-7 12316 df-8 12317 df-9 12318 df-n0 12510 df-z 12597 df-dec 12717 df-uz 12861 df-q 12973 df-rp 13017 df-xneg 13136 df-xadd 13137 df-xmul 13138 df-ioo 13373 df-ioc 13374 df-ico 13375 df-icc 13376 df-fz 13530 df-fzo 13677 df-fl 13814 df-mod 13892 df-seq 14025 df-exp 14085 df-fac 14296 df-bc 14325 df-hash 14353 df-shft 15089 df-cj 15121 df-re 15122 df-im 15123 df-sqrt 15257 df-abs 15258 df-limsup 15490 df-clim 15507 df-rlim 15508 df-sum 15706 df-ef 16086 df-sin 16088 df-cos 16089 df-pi 16091 df-struct 17167 df-sets 17184 df-slot 17202 df-ndx 17214 df-base 17231 df-ress 17254 df-plusg 17287 df-mulr 17288 df-starv 17289 df-sca 17290 df-vsca 17291 df-ip 17292 df-tset 17293 df-ple 17294 df-ds 17296 df-unif 17297 df-hom 17298 df-cco 17299 df-rest 17439 df-topn 17440 df-0g 17458 df-gsum 17459 df-topgen 17460 df-pt 17461 df-prds 17464 df-xrs 17519 df-qtop 17524 df-imas 17525 df-xps 17527 df-mre 17601 df-mrc 17602 df-acs 17604 df-mgm 18623 df-sgrp 18702 df-mnd 18718 df-submnd 18767 df-mulg 19056 df-cntz 19305 df-cmn 19769 df-psmet 21319 df-xmet 21320 df-met 21321 df-bl 21322 df-mopn 21323 df-fbas 21324 df-fg 21325 df-cnfld 21328 df-top 22849 df-topon 22866 df-topsp 22888 df-bases 22901 df-cld 22974 df-ntr 22975 df-cls 22976 df-nei 23053 df-lp 23091 df-perf 23092 df-cn 23182 df-cnp 23183 df-haus 23270 df-tx 23517 df-hmeo 23710 df-fil 23801 df-fm 23893 df-flim 23894 df-flf 23895 df-xms 24276 df-ms 24277 df-tms 24278 df-cncf 24841 df-limc 25838 df-dv 25839 df-log 26535 df-cxp 26536 df-logb 26745 |
| This theorem is referenced by: (None) |
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