let X be non empty set ; :: thesis: for S being SigmaField of X
for M being sigma_Measure of S
for E being Element of S
for F being Functional_Sequence of X,ExtREAL st E = dom (F . 0 ) & F is additive & F is with_the_same_dom & ( for n being Nat holds
( F . n is_measurable_on E & F . n is nonnegative ) ) holds
ex I being ExtREAL_sequence st
for n being Nat holds
( I . n = Integral M,(F . n) & Integral M,((Partial_Sums F) . n) = (Partial_Sums I) . n )

let S be SigmaField of X; :: thesis: for M being sigma_Measure of S
for E being Element of S
for F being Functional_Sequence of X,ExtREAL st E = dom (F . 0 ) & F is additive & F is with_the_same_dom & ( for n being Nat holds
( F . n is_measurable_on E & F . n is nonnegative ) ) holds
ex I being ExtREAL_sequence st
for n being Nat holds
( I . n = Integral M,(F . n) & Integral M,((Partial_Sums F) . n) = (Partial_Sums I) . n )

let M be sigma_Measure of S; :: thesis: for E being Element of S
for F being Functional_Sequence of X,ExtREAL st E = dom (F . 0 ) & F is additive & F is with_the_same_dom & ( for n being Nat holds
( F . n is_measurable_on E & F . n is nonnegative ) ) holds
ex I being ExtREAL_sequence st
for n being Nat holds
( I . n = Integral M,(F . n) & Integral M,((Partial_Sums F) . n) = (Partial_Sums I) . n )

let E be Element of S; :: thesis: for F being Functional_Sequence of X,ExtREAL st E = dom (F . 0 ) & F is additive & F is with_the_same_dom & ( for n being Nat holds
( F . n is_measurable_on E & F . n is nonnegative ) ) holds
ex I being ExtREAL_sequence st
for n being Nat holds
( I . n = Integral M,(F . n) & Integral M,((Partial_Sums F) . n) = (Partial_Sums I) . n )

let F be Functional_Sequence of X,ExtREAL ; :: thesis: ( E = dom (F . 0 ) & F is additive & F is with_the_same_dom & ( for n being Nat holds
( F . n is_measurable_on E & F . n is nonnegative ) ) implies ex I being ExtREAL_sequence st
for n being Nat holds
( I . n = Integral M,(F . n) & Integral M,((Partial_Sums F) . n) = (Partial_Sums I) . n ) )

assume that
A1: E = dom (F . 0 ) and
A3: F is additive and
A4: F is with_the_same_dom and
A2: for n being Nat holds
( F . n is_measurable_on E & F . n is nonnegative ) ; :: thesis: ex I being ExtREAL_sequence st
for n being Nat holds
( I . n = Integral M,(F . n) & Integral M,((Partial_Sums F) . n) = (Partial_Sums I) . n )

G3: for n being Nat holds F . n is without-infty by A2, MESFUNC5:18;
deffunc H1( Element of NAT ) -> Element of ExtREAL = Integral M,(F . $1);
consider I being Function of NAT ,ExtREAL such that
A6: for n being Element of NAT holds I . n = H1(n) from FUNCT_2:sch 4();
reconsider I = I as ExtREAL_sequence ;
take I ; :: thesis: for n being Nat holds
( I . n = Integral M,(F . n) & Integral M,((Partial_Sums F) . n) = (Partial_Sums I) . n )

set PF = Partial_Sums F;
thus for n being Nat holds
( I . n = Integral M,(F . n) & Integral M,((Partial_Sums F) . n) = (Partial_Sums I) . n ) :: thesis: verum
proof
let n be Nat; :: thesis: ( I . n = Integral M,(F . n) & Integral M,((Partial_Sums F) . n) = (Partial_Sums I) . n )
reconsider n' = n as Element of NAT by ORDINAL1:def 13;
I . n = Integral M,(F . n') by A6;
hence I . n = Integral M,(F . n) ; :: thesis: Integral M,((Partial_Sums F) . n) = (Partial_Sums I) . n
defpred S1[ Nat] means Integral M,((Partial_Sums F) . $1) = (Partial_Sums I) . $1;
set PI = Partial_Sums I;
Integral M,((Partial_Sums F) . 0 ) = Integral M,(F . 0 ) by Def0;
then Integral M,((Partial_Sums F) . 0 ) = I . 0 by A6;
then A8: S1[ 0 ] by Def1;
B1: for k being Nat st S1[k] holds
S1[k + 1]
proof
let k be Nat; :: thesis: ( S1[k] implies S1[k + 1] )
assume B2: S1[k] ; :: thesis: S1[k + 1]
reconsider k1 = k + 1 as Nat ;
A12: ( dom ((Partial_Sums F) . k) = E & dom (F . (k + 1)) = E ) by A1, A3, A4, ADD0, MESFUNC8:def 2;
A9: ( (Partial_Sums F) . k is_measurable_on E & F . (k + 1) is_measurable_on E & (Partial_Sums F) . k is nonnegative & F . (k + 1) is nonnegative ) by A2, G3, ADD1, ADD3C;
then consider D being Element of S such that
A11: ( D = dom (((Partial_Sums F) . k) + (F . (k + 1))) & integral+ M,(((Partial_Sums F) . k) + (F . (k + 1))) = (integral+ M,(((Partial_Sums F) . k) | D)) + (integral+ M,((F . (k + 1)) | D)) ) by A12, MESFUNC5:84;
D = (dom ((Partial_Sums F) . k)) /\ (dom (F . (k + 1))) by A9, A11, MESFUNC5:28
.= E by A12 ;
then A14: ( ((Partial_Sums F) . k) | D = (Partial_Sums F) . k & (F . (k + 1)) | D = F . (k + 1) ) by A12, RELAT_1:97;
( dom ((Partial_Sums F) . (k + 1)) = E & (Partial_Sums F) . (k + 1) is_measurable_on E & (Partial_Sums F) . (k + 1) is nonnegative ) by A1, A3, A4, G3, A2, ADD3C, ADD1, ADD0;
then Integral M,((Partial_Sums F) . (k + 1)) = integral+ M,((Partial_Sums F) . (k + 1)) by MESFUNC5:94
.= (integral+ M,(((Partial_Sums F) . k) | D)) + (integral+ M,((F . (k + 1)) | D)) by A11, Def0
.= (Integral M,((Partial_Sums F) . k)) + (integral+ M,((F . (k + 1)) | D)) by A9, A12, A14, MESFUNC5:94
.= (Integral M,((Partial_Sums F) . k)) + (Integral M,(F . (k + 1))) by A9, A12, A14, MESFUNC5:94
.= ((Partial_Sums I) . k) + (I . (k + 1)) by A6, B2 ;
hence S1[k + 1] by Def1; :: thesis: verum
end;
for k being Nat holds S1[k] from NAT_1:sch 2(A8, B1);
hence Integral M,((Partial_Sums F) . n) = (Partial_Sums I) . n ; :: thesis: verum
end;