let f be nonnegative Function of [:NAT,NAT:],ExtREAL; for seq being ExtREAL_sequence st ( for m being Element of NAT holds
( ProjMap2 (f,m) is non-decreasing & seq . m = lim (ProjMap2 (f,m)) ) ) holds
( lim_in_cod2 (Partial_Sums_in_cod2 f) is non-decreasing & Sum seq = lim (lim_in_cod2 (Partial_Sums_in_cod2 f)) )
let seq be ExtREAL_sequence; ( ( for m being Element of NAT holds
( ProjMap2 (f,m) is non-decreasing & seq . m = lim (ProjMap2 (f,m)) ) ) implies ( lim_in_cod2 (Partial_Sums_in_cod2 f) is non-decreasing & Sum seq = lim (lim_in_cod2 (Partial_Sums_in_cod2 f)) ) )
assume A1:
for m being Element of NAT holds
( ProjMap2 (f,m) is non-decreasing & seq . m = lim (ProjMap2 (f,m)) )
; ( lim_in_cod2 (Partial_Sums_in_cod2 f) is non-decreasing & Sum seq = lim (lim_in_cod2 (Partial_Sums_in_cod2 f)) )
then A2:
Sum seq <= lim_inf (lim_in_cod2 (Partial_Sums_in_cod2 f))
by Th83;
A3:
for n, m being Nat holds f . (n,m) <= seq . m
proof
let n,
m be
Nat;
f . (n,m) <= seq . m
reconsider m1 =
m as
Element of
NAT by ORDINAL1:def 12;
ProjMap2 (
f,
m1) is
non-decreasing
by A1;
then
lim (ProjMap2 (f,m1)) = sup (ProjMap2 (f,m1))
by RINFSUP2:37;
then A4:
seq . m = sup (ProjMap2 (f,m1))
by A1;
A5:
n is
Element of
NAT
by ORDINAL1:def 12;
dom (ProjMap2 (f,m1)) = NAT
by FUNCT_2:def 1;
then
(ProjMap2 (f,m1)) . n <= sup (rng (ProjMap2 (f,m1)))
by A5, FUNCT_1:3, XXREAL_2:4;
then
(ProjMap2 (f,m1)) . n <= sup (ProjMap2 (f,m1))
by RINFSUP2:def 1;
hence
f . (
n,
m)
<= seq . m
by A4, A5, MESFUNC9:def 7;
verum
end;
for n, m being Nat st m <= n holds
(lim_in_cod2 (Partial_Sums_in_cod2 f)) . m <= (lim_in_cod2 (Partial_Sums_in_cod2 f)) . n
proof
let n,
m be
Nat;
( m <= n implies (lim_in_cod2 (Partial_Sums_in_cod2 f)) . m <= (lim_in_cod2 (Partial_Sums_in_cod2 f)) . n )
assume C1:
m <= n
;
(lim_in_cod2 (Partial_Sums_in_cod2 f)) . m <= (lim_in_cod2 (Partial_Sums_in_cod2 f)) . n
reconsider m1 =
m,
n1 =
n as
Element of
NAT by ORDINAL1:def 12;
C2:
(
(lim_in_cod2 (Partial_Sums_in_cod2 f)) . m = lim (ProjMap1 ((Partial_Sums_in_cod2 f),m1)) &
(lim_in_cod2 (Partial_Sums_in_cod2 f)) . n = lim (ProjMap1 ((Partial_Sums_in_cod2 f),n1)) )
by D1DEF6;
C3:
(
ProjMap1 (
(Partial_Sums_in_cod2 f),
m1) is
convergent &
ProjMap1 (
(Partial_Sums_in_cod2 f),
n1) is
convergent )
by RINFSUP2:37;
for
k being
Nat holds
(ProjMap1 ((Partial_Sums_in_cod2 f),m1)) . k <= (ProjMap1 ((Partial_Sums_in_cod2 f),n1)) . k
proof
let k be
Nat;
(ProjMap1 ((Partial_Sums_in_cod2 f),m1)) . k <= (ProjMap1 ((Partial_Sums_in_cod2 f),n1)) . k
reconsider k1 =
k as
Element of
NAT by ORDINAL1:def 12;
(
(ProjMap1 ((Partial_Sums_in_cod2 f),m1)) . k1 = (Partial_Sums_in_cod2 f) . (
m1,
k1) &
(ProjMap1 ((Partial_Sums_in_cod2 f),n1)) . k1 = (Partial_Sums_in_cod2 f) . (
n1,
k1) )
by MESFUNC9:def 6;
hence
(ProjMap1 ((Partial_Sums_in_cod2 f),m1)) . k <= (ProjMap1 ((Partial_Sums_in_cod2 f),n1)) . k
by A1, C1, Th89;
verum
end;
hence
(lim_in_cod2 (Partial_Sums_in_cod2 f)) . m <= (lim_in_cod2 (Partial_Sums_in_cod2 f)) . n
by C2, C3, RINFSUP2:38;
verum
end;
hence
lim_in_cod2 (Partial_Sums_in_cod2 f) is non-decreasing
by RINFSUP2:7; Sum seq = lim (lim_in_cod2 (Partial_Sums_in_cod2 f))
then B1:
lim_in_cod2 (Partial_Sums_in_cod2 f) is convergent
by RINFSUP2:37;
then B3:
Sum seq <= lim (lim_in_cod2 (Partial_Sums_in_cod2 f))
by A2, RINFSUP2:41;
for n being Nat holds (lim_in_cod2 (Partial_Sums_in_cod2 f)) . n <= Sum seq
then
lim_sup (lim_in_cod2 (Partial_Sums_in_cod2 f)) <= Sum seq
by Th86;
then
lim (lim_in_cod2 (Partial_Sums_in_cod2 f)) <= Sum seq
by B1, RINFSUP2:41;
hence
Sum seq = lim (lim_in_cod2 (Partial_Sums_in_cod2 f))
by B3, XXREAL_0:1; verum