let a be Real; for Z being open Subset of REAL
for f being PartFunc of REAL ,REAL st Z c= dom ((1 / (1 - (log number_e ,a))) (#) (exp_R / (exp_R * f))) & ( for x being Real st x in Z holds
f . x = x * (log number_e ,a) ) & a > 0 & a <> number_e holds
( (1 / (1 - (log number_e ,a))) (#) (exp_R / (exp_R * f)) is_differentiable_on Z & ( for x being Real st x in Z holds
(((1 / (1 - (log number_e ,a))) (#) (exp_R / (exp_R * f))) `| Z) . x = (exp_R . x) / (a #R x) ) )
let Z be open Subset of REAL ; for f being PartFunc of REAL ,REAL st Z c= dom ((1 / (1 - (log number_e ,a))) (#) (exp_R / (exp_R * f))) & ( for x being Real st x in Z holds
f . x = x * (log number_e ,a) ) & a > 0 & a <> number_e holds
( (1 / (1 - (log number_e ,a))) (#) (exp_R / (exp_R * f)) is_differentiable_on Z & ( for x being Real st x in Z holds
(((1 / (1 - (log number_e ,a))) (#) (exp_R / (exp_R * f))) `| Z) . x = (exp_R . x) / (a #R x) ) )
let f be PartFunc of REAL ,REAL ; ( Z c= dom ((1 / (1 - (log number_e ,a))) (#) (exp_R / (exp_R * f))) & ( for x being Real st x in Z holds
f . x = x * (log number_e ,a) ) & a > 0 & a <> number_e implies ( (1 / (1 - (log number_e ,a))) (#) (exp_R / (exp_R * f)) is_differentiable_on Z & ( for x being Real st x in Z holds
(((1 / (1 - (log number_e ,a))) (#) (exp_R / (exp_R * f))) `| Z) . x = (exp_R . x) / (a #R x) ) ) )
assume that
A1:
Z c= dom ((1 / (1 - (log number_e ,a))) (#) (exp_R / (exp_R * f)))
and
A2:
for x being Real st x in Z holds
f . x = x * (log number_e ,a)
and
A3:
a > 0
and
A4:
a <> number_e
; ( (1 / (1 - (log number_e ,a))) (#) (exp_R / (exp_R * f)) is_differentiable_on Z & ( for x being Real st x in Z holds
(((1 / (1 - (log number_e ,a))) (#) (exp_R / (exp_R * f))) `| Z) . x = (exp_R . x) / (a #R x) ) )
Z c= dom (exp_R / (exp_R * f))
by A1, VALUED_1:def 5;
then
Z c= (dom exp_R ) /\ ((dom (exp_R * f)) \ ((exp_R * f) " {0 }))
by RFUNCT_1:def 4;
then A5:
Z c= dom (exp_R * f)
by XBOOLE_1:1;
then A6:
exp_R * f is_differentiable_on Z
by A2, A3, Th11;
A7:
for x being Real st x in Z holds
(exp_R * f) . x <> 0
exp_R is_differentiable_on Z
by FDIFF_1:34, TAYLOR_1:16;
then A8:
exp_R / (exp_R * f) is_differentiable_on Z
by A6, A7, FDIFF_2:21;
A9:
1 - (log number_e ,a) <> 0
proof
A10:
number_e <> 1
by TAYLOR_1:11;
assume
1
- (log number_e ,a) = 0
;
contradiction
then
log number_e ,
a = log number_e ,
number_e
by A10, POWER:60, TAYLOR_1:11;
then a =
number_e to_power (log number_e ,number_e )
by A3, A10, POWER:def 3, TAYLOR_1:11
.=
number_e
by A10, POWER:def 3, TAYLOR_1:11
;
hence
contradiction
by A4;
verum
end;
for x being Real st x in Z holds
(((1 / (1 - (log number_e ,a))) (#) (exp_R / (exp_R * f))) `| Z) . x = (exp_R . x) / (a #R x)
proof
let x be
Real;
( x in Z implies (((1 / (1 - (log number_e ,a))) (#) (exp_R / (exp_R * f))) `| Z) . x = (exp_R . x) / (a #R x) )
A11:
exp_R is_differentiable_in x
by SIN_COS:70;
A12:
a #R x > 0
by A3, PREPOWER:95;
assume A13:
x in Z
;
(((1 / (1 - (log number_e ,a))) (#) (exp_R / (exp_R * f))) `| Z) . x = (exp_R . x) / (a #R x)
then A14:
(exp_R * f) . x =
exp_R . (f . x)
by A5, FUNCT_1:22
.=
exp_R . (x * (log number_e ,a))
by A2, A13
.=
a #R x
by A3, Th1
;
A15:
(
exp_R * f is_differentiable_in x &
(exp_R * f) . x <> 0 )
by A6, A7, A13, FDIFF_1:16;
(((1 / (1 - (log number_e ,a))) (#) (exp_R / (exp_R * f))) `| Z) . x =
(1 / (1 - (log number_e ,a))) * (diff (exp_R / (exp_R * f)),x)
by A1, A8, A13, FDIFF_1:28
.=
(1 / (1 - (log number_e ,a))) * ((((diff exp_R ,x) * ((exp_R * f) . x)) - ((diff (exp_R * f),x) * (exp_R . x))) / (((exp_R * f) . x) ^2 ))
by A11, A15, FDIFF_2:14
.=
(1 / (1 - (log number_e ,a))) * ((((exp_R . x) * (a #R x)) - ((diff (exp_R * f),x) * (exp_R . x))) / ((a #R x) ^2 ))
by A14, SIN_COS:70
.=
(1 / (1 - (log number_e ,a))) * (((exp_R . x) * ((a #R x) - (diff (exp_R * f),x))) / ((a #R x) ^2 ))
.=
(1 / (1 - (log number_e ,a))) * (((exp_R . x) * ((a #R x) - (((exp_R * f) `| Z) . x))) / ((a #R x) ^2 ))
by A6, A13, FDIFF_1:def 8
.=
(1 / (1 - (log number_e ,a))) * (((exp_R . x) * ((a #R x) - ((a #R x) * (log number_e ,a)))) / ((a #R x) ^2 ))
by A2, A3, A5, A13, Th11
.=
((1 / (1 - (log number_e ,a))) * (((1 - (log number_e ,a)) * (exp_R . x)) * (a #R x))) / ((a #R x) ^2 )
by XCMPLX_1:75
.=
((((1 / (1 - (log number_e ,a))) * (1 - (log number_e ,a))) * (exp_R . x)) * (a #R x)) / ((a #R x) ^2 )
.=
((1 * (exp_R . x)) * (a #R x)) / ((a #R x) ^2 )
by A9, XCMPLX_1:107
.=
(exp_R . x) / (a #R x)
by A12, XCMPLX_1:92
;
hence
(((1 / (1 - (log number_e ,a))) (#) (exp_R / (exp_R * f))) `| Z) . x = (exp_R . x) / (a #R x)
;
verum
end;
hence
( (1 / (1 - (log number_e ,a))) (#) (exp_R / (exp_R * f)) is_differentiable_on Z & ( for x being Real st x in Z holds
(((1 / (1 - (log number_e ,a))) (#) (exp_R / (exp_R * f))) `| Z) . x = (exp_R . x) / (a #R x) ) )
by A1, A8, FDIFF_1:28; verum