let X be non empty set ; for S being SigmaField of X
for M being sigma_Measure of S
for f being PartFunc of X,COMPLEX
for r being Real st f is_integrable_on M holds
( r (#) f is_integrable_on M & Integral M,(r (#) f) = r * (Integral M,f) )
let S be SigmaField of X; for M being sigma_Measure of S
for f being PartFunc of X,COMPLEX
for r being Real st f is_integrable_on M holds
( r (#) f is_integrable_on M & Integral M,(r (#) f) = r * (Integral M,f) )
let M be sigma_Measure of S; for f being PartFunc of X,COMPLEX
for r being Real st f is_integrable_on M holds
( r (#) f is_integrable_on M & Integral M,(r (#) f) = r * (Integral M,f) )
let f be PartFunc of X,COMPLEX ; for r being Real st f is_integrable_on M holds
( r (#) f is_integrable_on M & Integral M,(r (#) f) = r * (Integral M,f) )
let r be Real; ( f is_integrable_on M implies ( r (#) f is_integrable_on M & Integral M,(r (#) f) = r * (Integral M,f) ) )
A1:
Integral M,(r (#) (Re f)) = Integral M,(Re (r (#) f))
by Th2;
A2:
Integral M,(r (#) (Im f)) = Integral M,(Im (r (#) f))
by Th2;
assume A3:
f is_integrable_on M
; ( r (#) f is_integrable_on M & Integral M,(r (#) f) = r * (Integral M,f) )
then A4:
Re f is_integrable_on M
by Def4;
then A5:
Integral M,(Re f) < +infty
by MESFUNC6:90;
r (#) (Re f) is_integrable_on M
by A4, MESFUNC6:102;
then A6:
Re (r (#) f) is_integrable_on M
by Th2;
then A7:
Integral M,(Re (r (#) f)) < +infty
by MESFUNC6:90;
A8:
Im f is_integrable_on M
by A3, Def4;
then A9:
-infty < Integral M,(Im f)
by MESFUNC6:90;
A10:
Integral M,(Im f) < +infty
by A8, MESFUNC6:90;
-infty < Integral M,(Re f)
by A4, MESFUNC6:90;
then reconsider R1 = Integral M,(Re f), I1 = Integral M,(Im f) as Real by A5, A9, A10, XXREAL_0:14;
A11:
(R_EAL r) * (R_EAL R1) = r * R1
by Th1;
A12:
(R_EAL r) * (R_EAL I1) = r * I1
by Th1;
r (#) (Im f) is_integrable_on M
by A8, MESFUNC6:102;
then A13:
Im (r (#) f) is_integrable_on M
by Th2;
then A14:
-infty < Integral M,(Im (r (#) f))
by MESFUNC6:90;
A15:
Integral M,(Im (r (#) f)) < +infty
by A13, MESFUNC6:90;
-infty < Integral M,(Re (r (#) f))
by A6, MESFUNC6:90;
then reconsider R2 = Integral M,(Re (r (#) f)), I2 = Integral M,(Im (r (#) f)) as Real by A7, A14, A15, XXREAL_0:14;
A16:
Integral M,(r (#) (Im f)) = (R_EAL r) * (Integral M,(Im f))
by A8, MESFUNC6:102;
A17:
r (#) f is_integrable_on M
by A6, A13, Def4;
Integral M,(r (#) (Re f)) = (R_EAL r) * (Integral M,(Re f))
by A4, MESFUNC6:102;
then
R2 + (I2 * <i> ) = r * (R1 + (I1 * <i> ))
by A16, A1, A2, A11, A12;
then
Integral M,(r (#) f) = r * (R1 + (I1 * <i> ))
by A17, Def5;
hence
( r (#) f is_integrable_on M & Integral M,(r (#) f) = r * (Integral M,f) )
by A3, A6, A13, Def4, Def5; verum