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 . 0 is nonnegative & F is with_the_same_dom & ( for n being Nat holds F . n is_measurable_on E ) & ( for n, m being Nat st n <= m holds
for x being Element of X st x in E holds
(F . n) . x <= (F . m) . x ) & ( for x being Element of X st x in E holds
F # x is convergent ) holds
ex I being ExtREAL_sequence st
( ( for n being Nat holds I . n = Integral M,(F . n) ) & I is convergent & Integral M,(lim F) = lim I )
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 . 0 is nonnegative & F is with_the_same_dom & ( for n being Nat holds F . n is_measurable_on E ) & ( for n, m being Nat st n <= m holds
for x being Element of X st x in E holds
(F . n) . x <= (F . m) . x ) & ( for x being Element of X st x in E holds
F # x is convergent ) holds
ex I being ExtREAL_sequence st
( ( for n being Nat holds I . n = Integral M,(F . n) ) & I is convergent & Integral M,(lim F) = lim I )
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 . 0 is nonnegative & F is with_the_same_dom & ( for n being Nat holds F . n is_measurable_on E ) & ( for n, m being Nat st n <= m holds
for x being Element of X st x in E holds
(F . n) . x <= (F . m) . x ) & ( for x being Element of X st x in E holds
F # x is convergent ) holds
ex I being ExtREAL_sequence st
( ( for n being Nat holds I . n = Integral M,(F . n) ) & I is convergent & Integral M,(lim F) = lim I )
let E be Element of S; :: thesis: for F being Functional_Sequence of X,ExtREAL st E = dom (F . 0 ) & F . 0 is nonnegative & F is with_the_same_dom & ( for n being Nat holds F . n is_measurable_on E ) & ( for n, m being Nat st n <= m holds
for x being Element of X st x in E holds
(F . n) . x <= (F . m) . x ) & ( for x being Element of X st x in E holds
F # x is convergent ) holds
ex I being ExtREAL_sequence st
( ( for n being Nat holds I . n = Integral M,(F . n) ) & I is convergent & Integral M,(lim F) = lim I )
let F be Functional_Sequence of X,ExtREAL ; :: thesis: ( E = dom (F . 0 ) & F . 0 is nonnegative & F is with_the_same_dom & ( for n being Nat holds F . n is_measurable_on E ) & ( for n, m being Nat st n <= m holds
for x being Element of X st x in E holds
(F . n) . x <= (F . m) . x ) & ( for x being Element of X st x in E holds
F # x is convergent ) implies ex I being ExtREAL_sequence st
( ( for n being Nat holds I . n = Integral M,(F . n) ) & I is convergent & Integral M,(lim F) = lim I ) )
assume that
A0:
E = dom (F . 0 )
and
A1:
F . 0 is nonnegative
and
S1:
F is with_the_same_dom
and
A2:
for n being Nat holds F . n is_measurable_on E
and
A3:
for n, m being Nat st n <= m holds
for x being Element of X st x in E holds
(F . n) . x <= (F . m) . x
and
A4:
for x being Element of X st x in E holds
F # x is convergent
; :: thesis: ex I being ExtREAL_sequence st
( ( for n being Nat holds I . n = Integral M,(F . n) ) & I is convergent & Integral M,(lim F) = lim I )
E0:
for n being Nat holds F . n is nonnegative
E13:
lim F is_measurable_on E
by A4, A0, S1, A2, MESFUNC8:25;
per cases
( ex n being Nat st M . (E /\ (eq_dom (F . n),+infty )) <> 0 or for n being Nat holds M . (E /\ (eq_dom (F . n),+infty )) = 0 )
;
suppose
ex
n being
Nat st
M . (E /\ (eq_dom (F . n),+infty )) <> 0
;
:: thesis: ex I being ExtREAL_sequence st
( ( for n being Nat holds I . n = Integral M,(F . n) ) & I is convergent & Integral M,(lim F) = lim I )then consider N being
Nat such that B1:
M . (E /\ (eq_dom (F . N),+infty )) <> 0
;
B0:
E = dom (F . N)
by A0, S1, MESFUNC8:def 2;
then reconsider EE =
E /\ (eq_dom (F . N),+infty ) as
Element of
S by A2, MESFUNC1:37;
B2:
EE c= E
by XBOOLE_1:17;
then
EE c= dom (F . N)
by A0, S1, MESFUNC8:def 2;
then B3:
EE = dom ((F . N) | EE)
by RELAT_1:91;
B4:
F . N is_measurable_on EE
by A2, B2, MESFUNC1:34;
EE = (dom (F . N)) /\ EE
by B3, RELAT_1:90;
then B5:
(F . N) | EE is_measurable_on EE
by B4, MESFUNC5:48;
B9:
F . N is
nonnegative
by E0;
EE = eq_dom ((F . N) | EE),
+infty
then
M . (EE /\ (eq_dom ((F . N) | EE),+infty )) <> 0
by B1;
then C0:
Integral M,
((F . N) | EE) = +infty
by B3, B5, B9, Lem13, MESFUNC5:21;
F . N is_measurable_on E
by A2;
then
Integral M,
((F . N) | EE) <= Integral M,
((F . N) | E)
by B0, E0, B2, MESFUNC5:99;
then
+infty <= Integral M,
(F . N)
by C0, B0, RELAT_1:98;
then D1:
Integral M,
(F . N) = +infty
by XXREAL_0:4;
deffunc H1(
Element of
NAT )
-> Element of
ExtREAL =
Integral M,
(F . $1);
consider I being
Function of
NAT ,
ExtREAL such that D2:
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) ) & I is convergent & Integral M,(lim F) = lim I )D3:
for
n being
Nat holds
I . n = Integral M,
(F . n)
E5:
for
n,
m being
Element of
NAT st
m <= n holds
I . m <= I . n
proof
let n,
m be
Element of
NAT ;
:: thesis: ( m <= n implies I . m <= I . n )
assume E2:
m <= n
;
:: thesis: I . m <= I . n
E51:
(
E = dom (F . m) &
E = dom (F . n) &
F . m is
nonnegative )
by E0, S1, A0, MESFUNC8:def 2;
E52:
(
F . n is_measurable_on E &
F . m is_measurable_on E )
by A2;
for
x being
Element of
X st
x in E holds
(F . m) . x <= (F . n) . x
by E2, A3;
then
Integral M,
((F . m) | E) <= Integral M,
((F . n) | E)
by E51, E52, Prop3;
then
Integral M,
(F . m) <= Integral M,
((F . n) | E)
by E51, RELAT_1:97;
then
Integral M,
(F . m) <= Integral M,
(F . n)
by E51, RELAT_1:97;
then
I . m <= Integral M,
(F . n)
by D2;
hence
I . m <= I . n
by D2;
:: thesis: verum
end; then E4:
I is
non-decreasing
by RINFSUP2:7;
then E6:
(
I is
convergent &
lim I = sup I )
by RINFSUP2:37;
reconsider N1 =
N as
Element of
NAT by ORDINAL1:def 13;
E7:
(
I ^\ N1 is
non-decreasing &
sup I = sup (I ^\ N1) )
by E4, RINFSUP2:26;
for
k being
Element of
NAT holds
+infty <= (I ^\ N1) . k
then
I ^\ N1 is
convergent_to_+infty
by RINFSUP2:32;
then
lim (I ^\ N1) = +infty
by LIM;
then E9:
lim I = +infty
by E6, E7, RINFSUP2:37;
E12:
E = dom (lim F)
by A0, MESFUNC8:def 10;
(
lim F is
nonnegative &
M . (E /\ (eq_dom (lim F),+infty )) <> 0 )
proof
E10:
dom (lim F) = dom (F . 0 )
by MESFUNC8:def 10;
for
x being
set st
x in dom (lim F) holds
(lim F) . x >= 0
hence
lim F is
nonnegative
by SUPINF_2:71;
:: thesis: M . (E /\ (eq_dom (lim F),+infty )) <> 0
E14:
EE c= E /\ (eq_dom (lim F),+infty )
proof
let x be
set ;
:: according to TARSKI:def 3 :: thesis: ( not x in EE or x in E /\ (eq_dom (lim F),+infty ) )
assume E40:
x in EE
;
:: thesis: x in E /\ (eq_dom (lim F),+infty )
then E41:
(
x in E &
x in eq_dom (F . N),
+infty )
by XBOOLE_0:def 4;
reconsider x1 =
x as
Element of
X by E40;
(
x1 in dom (F . N) &
(F . N) . x1 = +infty )
by E41, MESFUNC1:def 16;
then E44:
(F # x1) . N = +infty
by MESFUNC5:def 13;
for
n,
m being
Element of
NAT st
m <= n holds
(F # x1) . m <= (F # x1) . n
then E46:
F # x1 is
non-decreasing
by RINFSUP2:7;
then E47:
(
F # x1 is
convergent &
lim (F # x1) = sup (F # x1) )
by RINFSUP2:37;
E48:
(
(F # x1) ^\ N1 is
non-decreasing &
sup (F # x1) = sup ((F # x1) ^\ N1) )
by E46, RINFSUP2:26;
((F # x1) ^\ N1) . 0 = (F # x1) . (0 + N)
by NAT_1:def 3;
then
for
n being
Element of
NAT holds
+infty <= ((F # x1) ^\ N1) . n
by E44, E48, RINFSUP2:7;
then
(F # x1) ^\ N1 is
convergent_to_+infty
by RINFSUP2:32;
then
lim ((F # x1) ^\ N1) = +infty
by LIM;
then
lim (F # x1) = +infty
by E47, E48, RINFSUP2:37;
then
(lim F) . x1 = +infty
by E10, E41, A0, MESFUNC8:def 10;
then
x in eq_dom (lim F),
+infty
by E12, E41, MESFUNC1:def 16;
hence
x in E /\ (eq_dom (lim F),+infty )
by E41, XBOOLE_0:def 4;
:: thesis: verum
end;
E16:
E /\ (eq_dom (lim F),+infty ) is
Element of
S
by E12, E13, MESFUNC1:37;
0 < M . (E /\ (eq_dom (F . N),+infty ))
by B1, SUPINF_2:70;
hence
M . (E /\ (eq_dom (lim F),+infty )) <> 0
by E16, E14, MEASURE1:62;
:: thesis: verum
end; hence
( ( for
n being
Nat holds
I . n = Integral M,
(F . n) ) &
I is
convergent &
Integral M,
(lim F) = lim I )
by E9, E12, E13, E4, D3, Lem13, RINFSUP2:37;
:: thesis: verum end; suppose F0:
for
n being
Nat holds
M . (E /\ (eq_dom (F . n),+infty )) = 0
;
:: thesis: ex I being ExtREAL_sequence st
( ( for n being Nat holds I . n = Integral M,(F . n) ) & I is convergent & Integral M,(lim F) = lim I )defpred S1[
Element of
NAT ,
set ]
means $2
= E /\ (eq_dom (F . $1),+infty );
F1:
for
n being
Element of
NAT ex
A being
Element of
S st
S1[
n,
A]
consider L being
Function of
NAT ,
S such that F2:
for
n being
Element of
NAT holds
S1[
n,
L . n]
from FUNCT_2:sch 3(F1);
F3:
rng L is
N_Sub_set_fam of
X
by MEASURE1:52;
rng L c= S
by RELAT_1:def 19;
then reconsider E0 =
rng L as
N_Measure_fam of
S by F3, MEASURE2:def 1;
F5:
M * L is
nonnegative
by MEASURE2:1;
F6:
for
n being
Element of
NAT st
0 <= n holds
(M * L) . n = 0
then
SUM (M * L) = (Ser (M * L)) . 0
by F5, SUPINF_2:67;
then
SUM (M * L) = (M * L) . 0
by SUPINF_2:63;
then
SUM (M * L) = 0
by F6;
then F7:
M . (union E0) <= 0
by MEASURE2:13;
F8:
M . (union E0) = 0
by F7, SUPINF_2:70;
F9:
E = dom (lim F)
by A0, MESFUNC8:def 10;
set E1 =
E \ (union E0);
LL1:
Integral M,
(lim F) = Integral M,
((lim F) | (E \ (union E0)))
by E13, F8, F9, MESFUNC5:101;
L4:
E \ (union E0) c= E
by XBOOLE_1:36;
then AA2:
for
n being
Nat holds
F . n is_measurable_on E \ (union E0)
by A2, MESFUNC1:34;
deffunc H1(
Nat)
-> Element of
bool [:X,ExtREAL :] =
(F . $1) | (E \ (union E0));
consider H being
Functional_Sequence of
X,
ExtREAL such that G1:
for
n being
Nat holds
H . n = H1(
n)
from SEQFUNC:sch 1();
G2:
for
n being
Nat holds
(
dom (H . n) = E \ (union E0) &
H . n is
without-infty &
H . n is
without+infty )
proof
let n be
Nat;
:: thesis: ( dom (H . n) = E \ (union E0) & H . n is without-infty & H . n is without+infty )
G20:
E \ (union E0) c= dom (F . n)
by L4, A0, S1, MESFUNC8:def 2;
dom (H . n) = dom ((F . n) | (E \ (union E0)))
by G1;
hence
dom (H . n) = E \ (union E0)
by G20, RELAT_1:91;
:: thesis: ( H . n is without-infty & H . n is without+infty )
(F . n) | (E \ (union E0)) is
nonnegative
by E0, MESFUNC5:21;
then
H . n is
nonnegative
by G1;
hence
H . n is
without-infty
by MESFUNC5:18;
:: thesis: H . n is without+infty
for
x being
set st
x in dom (H . n) holds
(H . n) . x < +infty
proof
let x be
set ;
:: thesis: ( x in dom (H . n) implies (H . n) . x < +infty )
assume
x in dom (H . n)
;
:: thesis: (H . n) . x < +infty
then
x in dom ((F . n) | (E \ (union E0)))
by G1;
then G5:
(
x in E \ (union E0) &
x in dom (F . n) )
by RELAT_1:86;
(H . n) . x = ((F . n) | (E \ (union E0))) . x
by G1;
then G4:
(H . n) . x = (F . n) . x
by G5, FUNCT_1:72;
assume
(H . n) . x >= +infty
;
:: thesis: contradiction
then
(F . n) . x = +infty
by G4, XXREAL_0:4;
then G7:
x in eq_dom (F . n),
+infty
by G5, MESFUNC1:def 16;
reconsider n1 =
n as
Element of
NAT by ORDINAL1:def 13;
(
L . n = E /\ (eq_dom (F . n1),+infty ) &
dom L = NAT )
by F2, FUNCT_2:def 1;
then
(
x in L . n &
L . n in rng L )
by G7, G5, L4, FUNCT_1:12, XBOOLE_0:def 4;
then
x in union E0
by TARSKI:def 4;
hence
contradiction
by G5, XBOOLE_0:def 5;
:: thesis: verum
end;
hence
H . n is
without+infty
by MESFUNC5:17;
:: thesis: verum
end;
for
n,
m being
Nat holds
dom (H . n) = dom (H . m)
then reconsider H =
H as
with_the_same_dom Functional_Sequence of
X,
ExtREAL by MESFUNC8:def 2;
defpred S2[
Element of
NAT ,
set ,
set ]
means $3
= (H . ($1 + 1)) - (H . $1);
K1:
for
n being
Element of
NAT for
x being
set ex
y being
set st
S2[
n,
x,
y]
;
consider G being
Function such that K3:
(
dom G = NAT &
G . 0 = H . 0 & ( for
n being
Element of
NAT holds
S2[
n,
G . n,
G . (n + 1)] ) )
from RECDEF_1:sch 1(K1);
J3:
for
n being
Nat holds
G . (n + 1) = (H . (n + 1)) - (H . n)
then
rng G c= PFuncs X,
ExtREAL
by TARSKI:def 3;
then reconsider G =
G as
Functional_Sequence of
X,
ExtREAL by K3, FUNCT_2:def 1, RELSET_1:11;
Y1:
for
n being
Nat holds
dom (G . n) = E \ (union E0)
Z1:
for
n being
Nat holds
G . n is
nonnegative
X0:
for
n1 being
set st
n1 in NAT holds
H . n1 = (Partial_Sums G) . n1
P2:
for
n being
Nat holds
(
H . n = (Partial_Sums G) . n &
lim H = lim (Partial_Sums G) )
by X0, FUNCT_2:18;
for
n,
m being
Nat holds
dom (G . n) = dom (G . m)
then reconsider G =
G as
with_the_same_dom Functional_Sequence of
X,
ExtREAL by MESFUNC8:def 2;
reconsider G =
G as
with_the_same_dom additive Functional_Sequence of
X,
ExtREAL by Z1, LIM4;
V1:
E \ (union E0) = dom (G . 0 )
by G2, K3;
T20:
for
k being
Nat holds
H . k is
real-valued
V3:
for
n being
Nat holds
G . n is_measurable_on E \ (union E0)
for
x being
Element of
X st
x in E \ (union E0) holds
G # x is
summable
then consider J being
ExtREAL_sequence such that Q2:
( ( for
n being
Nat holds
J . n = Integral M,
((G . n) | (E \ (union E0))) ) &
J is
summable &
Integral M,
((lim (Partial_Sums G)) | (E \ (union E0))) = Sum J )
by V1, V3, Z1, Th131;
deffunc H2(
Element of
NAT )
-> Element of
ExtREAL =
Integral M,
((F . $1) | (E \ (union E0)));
consider I being
Function of
NAT ,
ExtREAL such that P3:
for
n being
Element of
NAT holds
I . n = H2(
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) ) & I is convergent & Integral M,(lim F) = lim I )P4:
for
n being
Nat holds
I . n = Integral M,
(F . n)
for
n,
m being
Element of
NAT st
m <= n holds
I . m <= I . n
proof
let n,
m be
Element of
NAT ;
:: thesis: ( m <= n implies I . m <= I . n )
assume P51:
m <= n
;
:: thesis: I . m <= I . n
P52:
(
dom (F . m) = E &
dom (F . n) = E )
by A0, S1, MESFUNC8:def 2;
then P54:
for
x being
Element of
X st
x in dom (F . m) holds
(F . m) . x <= (F . n) . x
by A3, P51;
P55:
(
F . m is
nonnegative &
F . n is
nonnegative )
by E0;
(
F . m is_measurable_on E &
F . n is_measurable_on E )
by A2;
then
integral+ M,
(F . m) <= integral+ M,
(F . n)
by P52, P55, P54, MESFUNC5:91;
then
Integral M,
(F . m) <= integral+ M,
(F . n)
by P52, A2, P55, MESFUNC5:94;
then P56:
Integral M,
(F . m) <= Integral M,
(F . n)
by P52, A2, P55, MESFUNC5:94;
I . m <= Integral M,
(F . n)
by P4, P56;
hence
I . m <= I . n
by P4;
:: thesis: verum
end; then X1:
I is
non-decreasing
by RINFSUP2:7;
R3:
for
x being
Element of
X st
x in E \ (union E0) holds
F # x is
convergent
dom (lim (Partial_Sums G)) = dom (H . 0 )
by P2, MESFUNC8:def 10;
then R5:
dom (lim (Partial_Sums G)) = E \ (union E0)
by G2;
R2:
E \ (union E0) c= dom (F . 0 )
by A0, XBOOLE_1:36;
for
n being
set st
n in NAT holds
I . n = (Partial_Sums J) . n
then
I = Partial_Sums J
by FUNCT_2:18;
then
lim I = Integral M,
(lim H)
by P2, R5, Q2, RELAT_1:97;
hence
( ( for
n being
Nat holds
I . n = Integral M,
(F . n) ) &
I is
convergent &
Integral M,
(lim F) = lim I )
by P4, X1, LL1, R2, G1, R3, Lm15, RINFSUP2:37;
:: thesis: verum end; end;