let X be RealNormSpace-Sequence; for Y being RealNormSpace st Y is complete holds
for seq being sequence of (R_NormSpace_of_BoundedMultilinearOperators (X,Y)) st seq is Cauchy_sequence_by_Norm holds
seq is convergent
let Y be RealNormSpace; ( Y is complete implies for seq being sequence of (R_NormSpace_of_BoundedMultilinearOperators (X,Y)) st seq is Cauchy_sequence_by_Norm holds
seq is convergent )
assume A1:
Y is complete
; for seq being sequence of (R_NormSpace_of_BoundedMultilinearOperators (X,Y)) st seq is Cauchy_sequence_by_Norm holds
seq is convergent
let vseq be sequence of (R_NormSpace_of_BoundedMultilinearOperators (X,Y)); ( vseq is Cauchy_sequence_by_Norm implies vseq is convergent )
assume A2:
vseq is Cauchy_sequence_by_Norm
; vseq is convergent
defpred S1[ set , set ] means ex xseq being sequence of Y st
( ( for n being Nat holds xseq . n = (modetrans ((vseq . n),X,Y)) . $1 ) & xseq is convergent & $2 = lim xseq );
A3:
for x being Element of (product X) ex y being Element of Y st S1[x,y]
proof
let x be
Element of
(product X);
ex y being Element of Y st S1[x,y]
deffunc H1(
Nat)
-> Element of the
carrier of
Y =
(modetrans ((vseq . $1),X,Y)) . x;
consider xseq being
sequence of
Y such that A4:
for
n being
Element of
NAT holds
xseq . n = H1(
n)
from FUNCT_2:sch 4();
A5:
for
n being
Nat holds
xseq . n = H1(
n)
take
lim xseq
;
S1[x, lim xseq]
A6:
for
m,
k being
Nat holds
||.((xseq . m) - (xseq . k)).|| <= ||.((vseq . m) - (vseq . k)).|| * (NrProduct x)
proof
let m,
k be
Nat;
||.((xseq . m) - (xseq . k)).|| <= ||.((vseq . m) - (vseq . k)).|| * (NrProduct x)
reconsider h1 =
(vseq . m) - (vseq . k) as
Lipschitzian MultilinearOperator of
X,
Y by LOPBAN10:def 11;
k in NAT
by ORDINAL1:def 12;
then A7:
xseq . k = (modetrans ((vseq . k),X,Y)) . x
by A4;
a8:
vseq . m is
Lipschitzian MultilinearOperator of
X,
Y
by LOPBAN10:def 11;
a9:
vseq . k is
Lipschitzian MultilinearOperator of
X,
Y
by LOPBAN10:def 11;
m in NAT
by ORDINAL1:def 12;
then
xseq . m = (modetrans ((vseq . m),X,Y)) . x
by A4;
then
(xseq . m) - (xseq . k) = h1 . x
by A7, a8, a9, LOPBAN10:52;
hence
||.((xseq . m) - (xseq . k)).|| <= ||.((vseq . m) - (vseq . k)).|| * (NrProduct x)
by LOPBAN10:45;
verum
end;
now for e being Real st e > 0 holds
ex k being Nat st
for n, m being Nat st n >= k & m >= k holds
||.((xseq . n) - (xseq . m)).|| < elet e be
Real;
( e > 0 implies ex k being Nat st
for n, m being Nat st n >= k & m >= k holds
||.((xseq . n) - (xseq . m)).|| < e )assume A10:
e > 0
;
ex k being Nat st
for n, m being Nat st n >= k & m >= k holds
||.((xseq . n) - (xseq . m)).|| < ehence
ex
k being
Nat st
for
n,
m being
Nat st
n >= k &
m >= k holds
||.((xseq . n) - (xseq . m)).|| < e
;
verum end;
then
xseq is
Cauchy_sequence_by_Norm
by RSSPACE3:8;
hence
S1[
x,
lim xseq]
by A1, A5;
verum
end;
consider f being Function of the carrier of (product X), the carrier of Y such that
A20:
for x being Element of (product X) holds S1[x,f . x]
from FUNCT_2:sch 3(A3);
reconsider tseq = f as Function of (product X),Y ;
A21:
for u being Point of (product X)
for i being Element of dom X
for x being Point of (X . i) ex xseqi being sequence of Y st
( ( for n being Nat holds xseqi . n = ((modetrans ((vseq . n),X,Y)) * (reproj (i,u))) . x ) & xseqi is convergent & (tseq * (reproj (i,u))) . x = lim xseqi )
proof
let u be
Point of
(product X);
for i being Element of dom X
for x being Point of (X . i) ex xseqi being sequence of Y st
( ( for n being Nat holds xseqi . n = ((modetrans ((vseq . n),X,Y)) * (reproj (i,u))) . x ) & xseqi is convergent & (tseq * (reproj (i,u))) . x = lim xseqi )let i be
Element of
dom X;
for x being Point of (X . i) ex xseqi being sequence of Y st
( ( for n being Nat holds xseqi . n = ((modetrans ((vseq . n),X,Y)) * (reproj (i,u))) . x ) & xseqi is convergent & (tseq * (reproj (i,u))) . x = lim xseqi )let x be
Point of
(X . i);
ex xseqi being sequence of Y st
( ( for n being Nat holds xseqi . n = ((modetrans ((vseq . n),X,Y)) * (reproj (i,u))) . x ) & xseqi is convergent & (tseq * (reproj (i,u))) . x = lim xseqi )
reconsider v =
(reproj (i,u)) . x as
Point of
(product X) ;
consider xseq being
sequence of
Y such that A22:
( ( for
n being
Nat holds
xseq . n = (modetrans ((vseq . n),X,Y)) . v ) &
xseq is
convergent &
tseq . v = lim xseq )
by A20;
A23:
dom (reproj (i,u)) = the
carrier of
(X . i)
by FUNCT_2:def 1;
take
xseq
;
( ( for n being Nat holds xseq . n = ((modetrans ((vseq . n),X,Y)) * (reproj (i,u))) . x ) & xseq is convergent & (tseq * (reproj (i,u))) . x = lim xseq )
thus
for
n being
Nat holds
xseq . n = ((modetrans ((vseq . n),X,Y)) * (reproj (i,u))) . x
( xseq is convergent & (tseq * (reproj (i,u))) . x = lim xseq )proof
let n be
Nat;
xseq . n = ((modetrans ((vseq . n),X,Y)) * (reproj (i,u))) . x
thus xseq . n =
(modetrans ((vseq . n),X,Y)) . v
by A22
.=
(vseq . n) . ((reproj (i,u)) . x)
by LOPBAN10:def 13
.=
((vseq . n) * (reproj (i,u))) . x
by A23, FUNCT_1:13
.=
((modetrans ((vseq . n),X,Y)) * (reproj (i,u))) . x
by LOPBAN10:def 13
;
verum
end;
thus
xseq is
convergent
by A22;
(tseq * (reproj (i,u))) . x = lim xseq
thus
(tseq * (reproj (i,u))) . x = lim xseq
by A22, A23, FUNCT_1:13;
verum
end;
now for i being Element of dom X
for u being Point of (product X) holds tseq * (reproj (i,u)) is LinearOperator of (X . i),Ylet i be
Element of
dom X;
for u being Point of (product X) holds tseq * (reproj (i,u)) is LinearOperator of (X . i),Ylet u be
Point of
(product X);
tseq * (reproj (i,u)) is LinearOperator of (X . i),Yset tseqiu =
tseq * (reproj (i,u));
deffunc H1(
Nat)
-> Element of
K16(
K17( the
carrier of
(X . i), the
carrier of
Y)) =
(modetrans ((vseq . $1),X,Y)) * (reproj (i,u));
A24:
now for x, y being Point of (X . i) holds (tseq * (reproj (i,u))) . (x + y) = ((tseq * (reproj (i,u))) . x) + ((tseq * (reproj (i,u))) . y)let x,
y be
Point of
(X . i);
(tseq * (reproj (i,u))) . (x + y) = ((tseq * (reproj (i,u))) . x) + ((tseq * (reproj (i,u))) . y)consider xseq being
sequence of
Y such that A25:
for
n being
Nat holds
xseq . n = H1(
n)
. x
and A26:
xseq is
convergent
and A27:
(tseq * (reproj (i,u))) . x = lim xseq
by A21;
consider zseq being
sequence of
Y such that A28:
for
n being
Nat holds
zseq . n = H1(
n)
. (x + y)
and
zseq is
convergent
and A29:
(tseq * (reproj (i,u))) . (x + y) = lim zseq
by A21;
consider yseq being
sequence of
Y such that A30:
for
n being
Nat holds
yseq . n = H1(
n)
. y
and A31:
yseq is
convergent
and A32:
(tseq * (reproj (i,u))) . y = lim yseq
by A21;
now for n being Nat holds zseq . n = (xseq . n) + (yseq . n)end; then
zseq = xseq + yseq
by NORMSP_1:def 2;
hence
(tseq * (reproj (i,u))) . (x + y) = ((tseq * (reproj (i,u))) . x) + ((tseq * (reproj (i,u))) . y)
by A26, A27, A29, A31, A32, NORMSP_1:25;
verum end; now for x being Point of (X . i)
for a being Real holds (tseq * (reproj (i,u))) . (a * x) = a * ((tseq * (reproj (i,u))) . x)let x be
Point of
(X . i);
for a being Real holds (tseq * (reproj (i,u))) . (a * x) = a * ((tseq * (reproj (i,u))) . x)let a be
Real;
(tseq * (reproj (i,u))) . (a * x) = a * ((tseq * (reproj (i,u))) . x)consider xseq being
sequence of
Y such that A34:
for
n being
Nat holds
xseq . n = H1(
n)
. x
and A35:
xseq is
convergent
and A36:
(tseq * (reproj (i,u))) . x = lim xseq
by A21;
consider zseq being
sequence of
Y such that A37:
for
n being
Nat holds
zseq . n = H1(
n)
. (a * x)
and
zseq is
convergent
and A38:
(tseq * (reproj (i,u))) . (a * x) = lim zseq
by A21;
now for n being Nat holds zseq . n = a * (xseq . n)end; then
zseq = a * xseq
by NORMSP_1:def 5;
hence
(tseq * (reproj (i,u))) . (a * x) = a * ((tseq * (reproj (i,u))) . x)
by A35, A36, A38, NORMSP_1:28;
verum end; hence
tseq * (reproj (i,u)) is
LinearOperator of
(X . i),
Y
by A24, LOPBAN_1:def 5, VECTSP_1:def 20;
verum end;
then reconsider tseq = tseq as MultilinearOperator of X,Y by LOPBAN10:def 6;
then A45:
||.vseq.|| is convergent
by SEQ_4:41;
A46:
tseq is Lipschitzian
proof
take
lim ||.vseq.||
;
LOPBAN10:def 10 ( 0 <= lim ||.vseq.|| & ( for b1 being Element of the carrier of (product X) holds ||.(tseq . b1).|| <= (lim ||.vseq.||) * (NrProduct b1) ) )
A47:
now for x being Point of (product X) holds ||.(tseq . x).|| <= (lim ||.vseq.||) * (NrProduct x)let x be
Point of
(product X);
||.(tseq . x).|| <= (lim ||.vseq.||) * (NrProduct x)consider xseq being
sequence of
Y such that A48:
for
n being
Nat holds
xseq . n = (modetrans ((vseq . n),X,Y)) . x
and A49:
xseq is
convergent
and A50:
tseq . x = lim xseq
by A20;
A51:
||.(tseq . x).|| = lim ||.xseq.||
by A49, A50, LOPBAN_1:20;
A52:
for
m being
Nat holds
||.(xseq . m).|| <= ||.(vseq . m).|| * (NrProduct x)
A54:
for
n being
Nat holds
||.xseq.|| . n <= ((NrProduct x) (#) ||.vseq.||) . n
A58:
lim ((NrProduct x) (#) ||.vseq.||) = (lim ||.vseq.||) * (NrProduct x)
by B39, SEQ_2:8, SEQ_4:41;
||.xseq.|| is
convergent
by A49, A50, LOPBAN_1:20;
hence
||.(tseq . x).|| <= (lim ||.vseq.||) * (NrProduct x)
by A45, A51, A54, A58, SEQ_2:18;
verum end;
hence
(
0 <= lim ||.vseq.|| & ( for
b1 being
Element of the
carrier of
(product X) holds
||.(tseq . b1).|| <= (lim ||.vseq.||) * (NrProduct b1) ) )
by B39, A47, SEQ_2:17, SEQ_4:41;
verum
end;
A59:
for e being Real st e > 0 holds
ex k being Nat st
for n being Nat st n >= k holds
for x being Point of (product X) holds ||.(((modetrans ((vseq . n),X,Y)) . x) - (tseq . x)).|| <= e * (NrProduct x)
proof
let e be
Real;
( e > 0 implies ex k being Nat st
for n being Nat st n >= k holds
for x being Point of (product X) holds ||.(((modetrans ((vseq . n),X,Y)) . x) - (tseq . x)).|| <= e * (NrProduct x) )
assume
e > 0
;
ex k being Nat st
for n being Nat st n >= k holds
for x being Point of (product X) holds ||.(((modetrans ((vseq . n),X,Y)) . x) - (tseq . x)).|| <= e * (NrProduct x)
then consider k being
Nat such that A60:
for
n,
m being
Nat st
n >= k &
m >= k holds
||.((vseq . n) - (vseq . m)).|| < e
by A2, RSSPACE3:8;
take
k
;
for n being Nat st n >= k holds
for x being Point of (product X) holds ||.(((modetrans ((vseq . n),X,Y)) . x) - (tseq . x)).|| <= e * (NrProduct x)
now for n being Nat st n >= k holds
for x being Point of (product X) holds ||.(((modetrans ((vseq . n),X,Y)) . x) - (tseq . x)).|| <= e * (NrProduct x)let n be
Nat;
( n >= k implies for x being Point of (product X) holds ||.(((modetrans ((vseq . n),X,Y)) . x) - (tseq . x)).|| <= e * (NrProduct x) )assume A61:
n >= k
;
for x being Point of (product X) holds ||.(((modetrans ((vseq . n),X,Y)) . x) - (tseq . x)).|| <= e * (NrProduct x)now for x being Point of (product X) holds ||.(((modetrans ((vseq . n),X,Y)) . x) - (tseq . x)).|| <= e * (NrProduct x)let x be
Point of
(product X);
||.(((modetrans ((vseq . n),X,Y)) . x) - (tseq . x)).|| <= e * (NrProduct x)consider xseq being
sequence of
Y such that A62:
for
n being
Nat holds
xseq . n = (modetrans ((vseq . n),X,Y)) . x
and A63:
xseq is
convergent
and A64:
tseq . x = lim xseq
by A20;
A65:
for
m,
k being
Nat holds
||.((xseq . m) - (xseq . k)).|| <= ||.((vseq . m) - (vseq . k)).|| * (NrProduct x)
proof
let m,
k be
Nat;
||.((xseq . m) - (xseq . k)).|| <= ||.((vseq . m) - (vseq . k)).|| * (NrProduct x)
reconsider h1 =
(vseq . m) - (vseq . k) as
Lipschitzian MultilinearOperator of
X,
Y by LOPBAN10:def 11;
A66:
xseq . k = (modetrans ((vseq . k),X,Y)) . x
by A62;
a67:
vseq . m is
Lipschitzian MultilinearOperator of
X,
Y
by LOPBAN10:def 11;
a68:
vseq . k is
Lipschitzian MultilinearOperator of
X,
Y
by LOPBAN10:def 11;
xseq . m = (modetrans ((vseq . m),X,Y)) . x
by A62;
then
(xseq . m) - (xseq . k) = h1 . x
by A66, a67, a68, LOPBAN10:52;
hence
||.((xseq . m) - (xseq . k)).|| <= ||.((vseq . m) - (vseq . k)).|| * (NrProduct x)
by LOPBAN10:45;
verum
end; A69:
for
m being
Nat st
m >= k holds
||.((xseq . n) - (xseq . m)).|| <= e * (NrProduct x)
||.((xseq . n) - (tseq . x)).|| <= e * (NrProduct x)
hence
||.(((modetrans ((vseq . n),X,Y)) . x) - (tseq . x)).|| <= e * (NrProduct x)
by A62;
verum end; hence
for
x being
Point of
(product X) holds
||.(((modetrans ((vseq . n),X,Y)) . x) - (tseq . x)).|| <= e * (NrProduct x)
;
verum end;
hence
for
n being
Nat st
n >= k holds
for
x being
Point of
(product X) holds
||.(((modetrans ((vseq . n),X,Y)) . x) - (tseq . x)).|| <= e * (NrProduct x)
;
verum
end;
reconsider tseq = tseq as Lipschitzian MultilinearOperator of X,Y by A46;
reconsider tv = tseq as Point of (R_NormSpace_of_BoundedMultilinearOperators (X,Y)) by LOPBAN10:def 11;
A77:
for e being Real st e > 0 holds
ex k being Nat st
for n being Nat st n >= k holds
||.((vseq . n) - tv).|| <= e
for e being Real st e > 0 holds
ex m being Nat st
for n being Nat st n >= m holds
||.((vseq . n) - tv).|| < e
hence
vseq is convergent
by NORMSP_1:def 6; verum