Theorem rprelogbdiv 15839

Description: The logarithm of the quotient of two positive real numbers is the difference of logarithms. Property 3 of [Cohen4] p. 361. (Contributed by AV, 29-May-2020.)

Assertion

Ref	Expression
rprelogbdiv	|- ( ( ( B e. RR+ /\ B # 1 ) /\ ( A e. RR+ /\ C e. RR+ ) ) -> ( B logb ( A / C ) ) = ( ( B logb A ) - ( B logb C ) ) )

Proof of Theorem rprelogbdiv

Step	Hyp	Ref	Expression
1		neg1rr 9345	. . 3 |- -u 1 e. RR
2		rprelogbmulexp 15838	. . 3 |- ( ( ( B e. RR+ /\ B # 1 ) /\ ( A e. RR+ /\ C e. RR+ /\ -u 1 e. RR ) ) -> ( B logb ( A x. ( C ^c -u 1 ) ) ) = ( ( B logb A ) + ( -u 1 x. ( B logb C ) ) ) )
3	1, 2	mp3anr3 1373	. 2 |- ( ( ( B e. RR+ /\ B # 1 ) /\ ( A e. RR+ /\ C e. RR+ ) ) -> ( B logb ( A x. ( C ^c -u 1 ) ) ) = ( ( B logb A ) + ( -u 1 x. ( B logb C ) ) ) )
4		rpcn 9998	. . . . . . 7 |- ( A e. RR+ -> A e. CC )
5	4	adantr 276	. . . . . 6 |- ( ( A e. RR+ /\ C e. RR+ ) -> A e. CC )
6		rpcn 9998	. . . . . . 7 |- ( C e. RR+ -> C e. CC )
7	6	adantl 277	. . . . . 6 |- ( ( A e. RR+ /\ C e. RR+ ) -> C e. CC )
8		rpap0 10006	. . . . . . 7 |- ( C e. RR+ -> C # 0 )
9	8	adantl 277	. . . . . 6 |- ( ( A e. RR+ /\ C e. RR+ ) -> C # 0 )
10	5, 7, 9	divrecapd 9069	. . . . 5 |- ( ( A e. RR+ /\ C e. RR+ ) -> ( A / C ) = ( A x. ( 1 / C ) ) )
11		ax-1cn 8222	. . . . . . . . 9 |- 1 e. CC
12		rpcxpneg 15789	. . . . . . . . 9 |- ( ( C e. RR+ /\ 1 e. CC ) -> ( C ^c -u 1 ) = ( 1 / ( C ^c 1 ) ) )
13	11, 12	mpan2 425	. . . . . . . 8 |- ( C e. RR+ -> ( C ^c -u 1 ) = ( 1 / ( C ^c 1 ) ) )
14		rpcxp1 15781	. . . . . . . . 9 |- ( C e. RR+ -> ( C ^c 1 ) = C )
15	14	oveq2d 6068	. . . . . . . 8 |- ( C e. RR+ -> ( 1 / ( C ^c 1 ) ) = ( 1 / C ) )
16	13, 15	eqtrd 2267	. . . . . . 7 |- ( C e. RR+ -> ( C ^c -u 1 ) = ( 1 / C ) )
17	16	adantl 277	. . . . . 6 |- ( ( A e. RR+ /\ C e. RR+ ) -> ( C ^c -u 1 ) = ( 1 / C ) )
18	17	oveq2d 6068	. . . . 5 |- ( ( A e. RR+ /\ C e. RR+ ) -> ( A x. ( C ^c -u 1 ) ) = ( A x. ( 1 / C ) ) )
19	10, 18	eqtr4d 2270	. . . 4 |- ( ( A e. RR+ /\ C e. RR+ ) -> ( A / C ) = ( A x. ( C ^c -u 1 ) ) )
20	19	adantl 277	. . 3 |- ( ( ( B e. RR+ /\ B # 1 ) /\ ( A e. RR+ /\ C e. RR+ ) ) -> ( A / C ) = ( A x. ( C ^c -u 1 ) ) )
21	20	oveq2d 6068	. 2 |- ( ( ( B e. RR+ /\ B # 1 ) /\ ( A e. RR+ /\ C e. RR+ ) ) -> ( B logb ( A / C ) ) = ( B logb ( A x. ( C ^c -u 1 ) ) ) )
22		simpll 527	. . . . 5 |- ( ( ( B e. RR+ /\ B # 1 ) /\ ( A e. RR+ /\ C e. RR+ ) ) -> B e. RR+ )
23		simplr 529	. . . . 5 |- ( ( ( B e. RR+ /\ B # 1 ) /\ ( A e. RR+ /\ C e. RR+ ) ) -> B # 1 )
24		simprr 533	. . . . 5 |- ( ( ( B e. RR+ /\ B # 1 ) /\ ( A e. RR+ /\ C e. RR+ ) ) -> C e. RR+ )
25		rplogbcl 15828	. . . . 5 |- ( ( B e. RR+ /\ B # 1 /\ C e. RR+ ) -> ( B logb C ) e. RR )
26	22, 23, 24, 25	syl3anc 1274	. . . 4 |- ( ( ( B e. RR+ /\ B # 1 ) /\ ( A e. RR+ /\ C e. RR+ ) ) -> ( B logb C ) e. RR )
27		recn 8262	. . . 4 |- ( ( B logb C ) e. RR -> ( B logb C ) e. CC )
28		mulm1 8675	. . . . 5 |- ( ( B logb C ) e. CC -> ( -u 1 x. ( B logb C ) ) = -u ( B logb C ) )
29	28	oveq2d 6068	. . . 4 |- ( ( B logb C ) e. CC -> ( ( B logb A ) + ( -u 1 x. ( B logb C ) ) ) = ( ( B logb A ) + -u ( B logb C ) ) )
30	26, 27, 29	3syl 17	. . 3 |- ( ( ( B e. RR+ /\ B # 1 ) /\ ( A e. RR+ /\ C e. RR+ ) ) -> ( ( B logb A ) + ( -u 1 x. ( B logb C ) ) ) = ( ( B logb A ) + -u ( B logb C ) ) )
31		simprl 531	. . . . . 6 |- ( ( ( B e. RR+ /\ B # 1 ) /\ ( A e. RR+ /\ C e. RR+ ) ) -> A e. RR+ )
32		rplogbcl 15828	. . . . . 6 |- ( ( B e. RR+ /\ B # 1 /\ A e. RR+ ) -> ( B logb A ) e. RR )
33	22, 23, 31, 32	syl3anc 1274	. . . . 5 |- ( ( ( B e. RR+ /\ B # 1 ) /\ ( A e. RR+ /\ C e. RR+ ) ) -> ( B logb A ) e. RR )
34	33	recnd 8304	. . . 4 |- ( ( ( B e. RR+ /\ B # 1 ) /\ ( A e. RR+ /\ C e. RR+ ) ) -> ( B logb A ) e. CC )
35	26	recnd 8304	. . . 4 |- ( ( ( B e. RR+ /\ B # 1 ) /\ ( A e. RR+ /\ C e. RR+ ) ) -> ( B logb C ) e. CC )
36	34, 35	negsubd 8592	. . 3 |- ( ( ( B e. RR+ /\ B # 1 ) /\ ( A e. RR+ /\ C e. RR+ ) ) -> ( ( B logb A ) + -u ( B logb C ) ) = ( ( B logb A ) - ( B logb C ) ) )
37	30, 36	eqtr2d 2268	. 2 |- ( ( ( B e. RR+ /\ B # 1 ) /\ ( A e. RR+ /\ C e. RR+ ) ) -> ( ( B logb A ) - ( B logb C ) ) = ( ( B logb A ) + ( -u 1 x. ( B logb C ) ) ) )
38	3, 21, 37	3eqtr4d 2277	1 |- ( ( ( B e. RR+ /\ B # 1 ) /\ ( A e. RR+ /\ C e. RR+ ) ) -> ( B logb ( A / C ) ) = ( ( B logb A ) - ( B logb C ) ) )

Syntax hints:   -> wi 4   /\ wa 104   = wceq 1398   e. wcel 2205   class class class wbr 4111  (class class class)co 6052   CCcc 8127   RRcr 8128   0cc0 8129   1c1 8130   + caddc 8132   x. cmul 8134   - cmin 8446   -ucneg 8447   # cap 8857   / cdiv 8948   RR+crp 9989   ^c ccxp 15739   log_b clogb 15825

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 619  ax-in2 620  ax-io 717  ax-5 1496  ax-7 1497  ax-gen 1498  ax-ie1 1542  ax-ie2 1543  ax-8 1553  ax-10 1554  ax-11 1555  ax-i12 1556  ax-bndl 1558  ax-4 1559  ax-17 1575  ax-i9 1579  ax-ial 1583  ax-i5r 1584  ax-13 2207  ax-14 2208  ax-ext 2216  ax-coll 4227  ax-sep 4230  ax-nul 4238  ax-pow 4289  ax-pr 4324  ax-un 4556  ax-setind 4661  ax-iinf 4712  ax-cnex 8220  ax-resscn 8221  ax-1cn 8222  ax-1re 8223  ax-icn 8224  ax-addcl 8225  ax-addrcl 8226  ax-mulcl 8227  ax-mulrcl 8228  ax-addcom 8229  ax-mulcom 8230  ax-addass 8231  ax-mulass 8232  ax-distr 8233  ax-i2m1 8234  ax-0lt1 8235  ax-1rid 8236  ax-0id 8237  ax-rnegex 8238  ax-precex 8239  ax-cnre 8240  ax-pre-ltirr 8241  ax-pre-ltwlin 8242  ax-pre-lttrn 8243  ax-pre-apti 8244  ax-pre-ltadd 8245  ax-pre-mulgt0 8246  ax-pre-mulext 8247  ax-arch 8248  ax-caucvg 8249  ax-pre-suploc 8250  ax-addf 8251  ax-mulf 8252

This theorem depends on definitions:  df-bi 117  df-stab 839  df-dc 843  df-3or 1006  df-3an 1007  df-tru 1401  df-fal 1404  df-nf 1510  df-sb 1812  df-eu 2085  df-mo 2086  df-clab 2221  df-cleq 2227  df-clel 2230  df-nfc 2375  df-ne 2415  df-nel 2510  df-ral 2527  df-rex 2528  df-reu 2529  df-rmo 2530  df-rab 2531  df-v 2817  df-sbc 3045  df-csb 3141  df-dif 3215  df-un 3217  df-in 3219  df-ss 3226  df-nul 3511  df-if 3623  df-pw 3673  df-sn 3697  df-pr 3698  df-op 3700  df-uni 3917  df-int 3952  df-iun 3995  df-disj 4088  df-br 4112  df-opab 4174  df-mpt 4175  df-tr 4211  df-id 4416  df-po 4419  df-iso 4420  df-iord 4489  df-on 4491  df-ilim 4492  df-suc 4494  df-iom 4715  df-xp 4757  df-rel 4758  df-cnv 4759  df-co 4760  df-dm 4761  df-rn 4762  df-res 4763  df-ima 4764  df-iota 5314  df-fun 5356  df-fn 5357  df-f 5358  df-f1 5359  df-fo 5360  df-f1o 5361  df-fv 5362  df-isom 5363  df-riota 6005  df-ov 6055  df-oprab 6056  df-mpo 6057  df-of 6268  df-1st 6336  df-2nd 6337  df-recs 6538  df-irdg 6603  df-frec 6624  df-1o 6649  df-oadd 6653  df-er 6769  df-map 6886  df-pm 6887  df-en 6978  df-dom 6979  df-fin 6980  df-sup 7277  df-inf 7278  df-pnf 8312  df-mnf 8313  df-xr 8314  df-ltxr 8315  df-le 8316  df-sub 8448  df-neg 8449  df-reap 8851  df-ap 8858  df-div 8949  df-inn 9240  df-2 9298  df-3 9299  df-4 9300  df-n0 9499  df-z 9580  df-uz 9857  df-q 9955  df-rp 9990  df-xneg 10108  df-xadd 10109  df-ioo 10228  df-ico 10230  df-icc 10231  df-fz 10346  df-fzo 10481  df-seqfrec 10814  df-exp 10905  df-fac 11092  df-bc 11114  df-ihash 11143  df-shft 11504  df-cj 11531  df-re 11532  df-im 11533  df-rsqrt 11687  df-abs 11688  df-clim 11968  df-sumdc 12043  df-ef 12338  df-e 12339  df-rest 13471  df-topgen 13490  df-psmet 14708  df-xmet 14709  df-met 14710  df-bl 14711  df-mopn 14712  df-top 14880  df-topon 14893  df-bases 14925  df-ntr 14978  df-cn 15070  df-cnp 15071  df-tx 15135  df-cncf 15453  df-limced 15538  df-dvap 15539  df-relog 15740  df-rpcxp 15741  df-logb 15826

This theorem is referenced by:  logbrec  15842