let a be Real; :: thesis: for Z being open Subset of REAL
for f1, f2 being PartFunc of REAL,REAL st Z c= dom ((1 / (log (number_e,a))) (#) ((- (exp_R * f1)) (#) f2)) & ( for x being Real st x in Z holds
( f1 . x = - (x * (log (number_e,a))) & f2 . x = x + (1 / (log (number_e,a))) ) ) & a > 0 & a <> 1 holds
( (1 / (log (number_e,a))) (#) ((- (exp_R * f1)) (#) f2) is_differentiable_on Z & ( for x being Real st x in Z holds
(((1 / (log (number_e,a))) (#) ((- (exp_R * f1)) (#) f2)) `| Z) . x = x / (a #R x) ) )
let Z be open Subset of REAL; :: thesis: for f1, f2 being PartFunc of REAL,REAL st Z c= dom ((1 / (log (number_e,a))) (#) ((- (exp_R * f1)) (#) f2)) & ( for x being Real st x in Z holds
( f1 . x = - (x * (log (number_e,a))) & f2 . x = x + (1 / (log (number_e,a))) ) ) & a > 0 & a <> 1 holds
( (1 / (log (number_e,a))) (#) ((- (exp_R * f1)) (#) f2) is_differentiable_on Z & ( for x being Real st x in Z holds
(((1 / (log (number_e,a))) (#) ((- (exp_R * f1)) (#) f2)) `| Z) . x = x / (a #R x) ) )
let f1, f2 be PartFunc of REAL,REAL; :: thesis: ( Z c= dom ((1 / (log (number_e,a))) (#) ((- (exp_R * f1)) (#) f2)) & ( for x being Real st x in Z holds
( f1 . x = - (x * (log (number_e,a))) & f2 . x = x + (1 / (log (number_e,a))) ) ) & a > 0 & a <> 1 implies ( (1 / (log (number_e,a))) (#) ((- (exp_R * f1)) (#) f2) is_differentiable_on Z & ( for x being Real st x in Z holds
(((1 / (log (number_e,a))) (#) ((- (exp_R * f1)) (#) f2)) `| Z) . x = x / (a #R x) ) ) )
assume that
A1: Z c= dom ((1 / (log (number_e,a))) (#) ((- (exp_R * f1)) (#) f2)) and
A2: for x being Real st x in Z holds
( f1 . x = - (x * (log (number_e,a))) & f2 . x = x + (1 / (log (number_e,a))) ) and
A3: a > 0 and
A4: a <> 1 ; :: thesis: ( (1 / (log (number_e,a))) (#) ((- (exp_R * f1)) (#) f2) is_differentiable_on Z & ( for x being Real st x in Z holds
(((1 / (log (number_e,a))) (#) ((- (exp_R * f1)) (#) f2)) `| Z) . x = x / (a #R x) ) )
A5: for x being Real st x in Z holds
f2 . x = (1 * x) + (1 / (log (number_e,a))) by A2;
A6: Z c= dom ((- (exp_R * f1)) (#) f2) by A1, VALUED_1:def 5;
then A7: Z c= (dom (- (exp_R * f1))) /\ (dom f2) by VALUED_1:def 4;
then A8: Z c= dom (- (exp_R * f1)) by XBOOLE_1:18;
A9: for x being Real st x in Z holds
f1 . x = - (x * (log (number_e,a))) by A2;
then A10: - (exp_R * f1) is_differentiable_on Z by A3, A8, Th16;
A11: Z c= dom f2 by A7, XBOOLE_1:18;
then A12: f2 is_differentiable_on Z by A5, FDIFF_1:23;
then A13: (- (exp_R * f1)) (#) f2 is_differentiable_on Z by A6, A10, FDIFF_1:21;
A14: log (number_e,a) <> 0

proof

A15: number_e <> 1 by TAYLOR_1:11;
assume log (number_e,a) = 0 ; :: thesis: contradiction
then log (number_e,a) = log (number_e,1) by SIN_COS2:13, TAYLOR_1:13;
then a = number_e to_power (log (number_e,1)) by A3, A15, POWER:def 3, TAYLOR_1:11
.= 1 by A15, POWER:def 3, TAYLOR_1:11 ;
hence contradiction by A4; :: thesis: verum

end;

for x being Real st x in Z holds
(((1 / (log (number_e,a))) (#) ((- (exp_R * f1)) (#) f2)) `| Z) . x = x / (a #R x)

proof

let x be Real; :: thesis: ( x in Z implies (((1 / (log (number_e,a))) (#) ((- (exp_R * f1)) (#) f2)) `| Z) . x = x / (a #R x) )
assume A16: x in Z ; :: thesis: (((1 / (log (number_e,a))) (#) ((- (exp_R * f1)) (#) f2)) `| Z) . x = x / (a #R x)
then x in dom (- (exp_R * f1)) by A8;
then A17: x in dom (exp_R * f1) by VALUED_1:8;
A18: (- (exp_R * f1)) . x = - ((exp_R * f1) . x) by VALUED_1:8
.= - (exp_R . (f1 . x)) by A17, FUNCT_1:12
.= - (exp_R . (- (x * (log (number_e,a))))) by A2, A16
.= - (a #R (- x)) by A3, Th2 ;
(((1 / (log (number_e,a))) (#) ((- (exp_R * f1)) (#) f2)) `| Z) . x = (1 / (log (number_e,a))) * (diff (((- (exp_R * f1)) (#) f2),x)) by A1, A13, A16, FDIFF_1:20
.= (1 / (log (number_e,a))) * ((((- (exp_R * f1)) (#) f2) `| Z) . x) by A13, A16, FDIFF_1:def 7
.= (1 / (log (number_e,a))) * (((f2 . x) * (diff ((- (exp_R * f1)),x))) + (((- (exp_R * f1)) . x) * (diff (f2,x)))) by A6, A10, A12, A16, FDIFF_1:21
.= (1 / (log (number_e,a))) * (((f2 . x) * (((- (exp_R * f1)) `| Z) . x)) + (((- (exp_R * f1)) . x) * (diff (f2,x)))) by A10, A16, FDIFF_1:def 7
.= (1 / (log (number_e,a))) * (((f2 . x) * (((- (exp_R * f1)) `| Z) . x)) + (((- (exp_R * f1)) . x) * ((f2 `| Z) . x))) by A12, A16, FDIFF_1:def 7
.= (1 / (log (number_e,a))) * (((f2 . x) * ((a #R (- x)) * (log (number_e,a)))) + (((- (exp_R * f1)) . x) * ((f2 `| Z) . x))) by A3, A9, A8, A16, Th16
.= (1 / (log (number_e,a))) * (((f2 . x) * ((a #R (- x)) * (log (number_e,a)))) + (((- (exp_R * f1)) . x) * 1)) by A11, A5, A16, FDIFF_1:23
.= (1 / (log (number_e,a))) * ((((f2 . x) * (log (number_e,a))) - 1) * (a #R (- x))) by A18
.= (1 / (log (number_e,a))) * ((((x + (1 / (log (number_e,a)))) * (log (number_e,a))) - 1) * (a #R (- x))) by A2, A16
.= ((1 / (log (number_e,a))) * (((x * (log (number_e,a))) + ((1 / (log (number_e,a))) * (log (number_e,a)))) - 1)) * (a #R (- x))
.= ((1 / (log (number_e,a))) * (((x * (log (number_e,a))) + 1) - 1)) * (a #R (- x)) by A14, XCMPLX_1:106
.= (((1 / (log (number_e,a))) * (log (number_e,a))) * x) * (a #R (- x))
.= (1 * x) * (a #R (- x)) by A14, XCMPLX_1:106
.= x * (1 / (a #R x)) by A3, PREPOWER:76
.= x / (a #R x) by XCMPLX_1:99 ;
hence (((1 / (log (number_e,a))) (#) ((- (exp_R * f1)) (#) f2)) `| Z) . x = x / (a #R x) ; :: thesis: verum

end;

hence ( (1 / (log (number_e,a))) (#) ((- (exp_R * f1)) (#) f2) is_differentiable_on Z & ( for x being Real st x in Z holds
(((1 / (log (number_e,a))) (#) ((- (exp_R * f1)) (#) f2)) `| Z) . x = x / (a #R x) ) ) by A1, A13, FDIFF_1:20; :: thesis: verum