let M be non empty MetrSpace; for S being non empty compact TopSpace
for T being NormedLinearTopSpace st S = TopSpaceMetr M & T is complete & T is finite-dimensional & dim T <> 0 holds
for G being Subset of (Funcs ( the carrier of M, the carrier of T))
for H being non empty Subset of (MetricSpaceNorm (R_NormSpace_of_ContinuousFunctions (S,T))) st G = H holds
( (MetricSpaceNorm (R_NormSpace_of_ContinuousFunctions (S,T))) | H is totally_bounded iff ( G is equibounded & G is equicontinuous ) )
let S be non empty compact TopSpace; for T being NormedLinearTopSpace st S = TopSpaceMetr M & T is complete & T is finite-dimensional & dim T <> 0 holds
for G being Subset of (Funcs ( the carrier of M, the carrier of T))
for H being non empty Subset of (MetricSpaceNorm (R_NormSpace_of_ContinuousFunctions (S,T))) st G = H holds
( (MetricSpaceNorm (R_NormSpace_of_ContinuousFunctions (S,T))) | H is totally_bounded iff ( G is equibounded & G is equicontinuous ) )
let T be NormedLinearTopSpace; ( S = TopSpaceMetr M & T is complete & T is finite-dimensional & dim T <> 0 implies for G being Subset of (Funcs ( the carrier of M, the carrier of T))
for H being non empty Subset of (MetricSpaceNorm (R_NormSpace_of_ContinuousFunctions (S,T))) st G = H holds
( (MetricSpaceNorm (R_NormSpace_of_ContinuousFunctions (S,T))) | H is totally_bounded iff ( G is equibounded & G is equicontinuous ) ) )
assume that
A1:
S = TopSpaceMetr M
and
A2:
T is complete
and
A3:
( T is finite-dimensional & dim T <> 0 )
; for G being Subset of (Funcs ( the carrier of M, the carrier of T))
for H being non empty Subset of (MetricSpaceNorm (R_NormSpace_of_ContinuousFunctions (S,T))) st G = H holds
( (MetricSpaceNorm (R_NormSpace_of_ContinuousFunctions (S,T))) | H is totally_bounded iff ( G is equibounded & G is equicontinuous ) )
let G be Subset of (Funcs ( the carrier of M, the carrier of T)); for H being non empty Subset of (MetricSpaceNorm (R_NormSpace_of_ContinuousFunctions (S,T))) st G = H holds
( (MetricSpaceNorm (R_NormSpace_of_ContinuousFunctions (S,T))) | H is totally_bounded iff ( G is equibounded & G is equicontinuous ) )
let H be non empty Subset of (MetricSpaceNorm (R_NormSpace_of_ContinuousFunctions (S,T))); ( G = H implies ( (MetricSpaceNorm (R_NormSpace_of_ContinuousFunctions (S,T))) | H is totally_bounded iff ( G is equibounded & G is equicontinuous ) ) )
assume A4:
G = H
; ( (MetricSpaceNorm (R_NormSpace_of_ContinuousFunctions (S,T))) | H is totally_bounded iff ( G is equibounded & G is equicontinuous ) )
hence
( (MetricSpaceNorm (R_NormSpace_of_ContinuousFunctions (S,T))) | H is totally_bounded implies ( G is equibounded & G is equicontinuous ) )
by A1, A2, ASCOLI:13; ( G is equibounded & G is equicontinuous implies (MetricSpaceNorm (R_NormSpace_of_ContinuousFunctions (S,T))) | H is totally_bounded )
assume A5:
( G is equibounded & G is equicontinuous )
; (MetricSpaceNorm (R_NormSpace_of_ContinuousFunctions (S,T))) | H is totally_bounded
for x being Point of S
for Hx being non empty Subset of (MetricSpaceNorm T) st Hx = { (f . x) where f is Function of S,T : f in H } holds
(MetricSpaceNorm T) | (Cl Hx) is compact
proof
let x be
Point of
S;
for Hx being non empty Subset of (MetricSpaceNorm T) st Hx = { (f . x) where f is Function of S,T : f in H } holds
(MetricSpaceNorm T) | (Cl Hx) is compact let Hx be non
empty Subset of
(MetricSpaceNorm T);
( Hx = { (f . x) where f is Function of S,T : f in H } implies (MetricSpaceNorm T) | (Cl Hx) is compact )
assume A6:
Hx = { (f . x) where f is Function of S,T : f in H }
;
(MetricSpaceNorm T) | (Cl Hx) is compact
reconsider Tx =
Hx as non
empty Subset of
(TopSpaceNorm T) ;
reconsider Fx =
Hx as non
empty Subset of
T ;
A7:
Cl Fx = Cl Hx
by ASCOLI:1;
consider RNS being
RealNormSpace such that A8:
(
RNS = NORMSTR(# the
carrier of
T, the
ZeroF of
T, the
addF of
T, the
Mult of
T, the
normF of
T #) & the
topology of
T = the
topology of
(TopSpaceNorm RNS) )
by C0SP3:def 6;
A9:
(
RNS is
finite-dimensional &
dim RNS <> 0 )
by A3, A8, Th25;
reconsider Fx0 =
Fx as non
empty Subset of
RNS by A8;
A10:
for
a,
b being
Element of
RNS holds
(distance_by_norm_of RNS) . (
a,
b)
= (distance_by_norm_of T) . (
a,
b)
A12:
MetricSpaceNorm RNS = MetricSpaceNorm T
by A10, A8, BINOP_1:2;
then A13:
Cl Fx0 = Cl Fx
by A7, ASCOLI:1;
reconsider ClHx =
Cl Hx as non
empty Subset of
(MetricSpaceNorm RNS) by A8;
consider K being
Real such that A14:
for
f being
Function of the
carrier of
M, the
carrier of
T st
f in G holds
for
x being
Element of
M holds
||.(f . x).|| <= K
by A5;
reconsider x0 =
x as
Element of
M by A1;
set r =
K + 1;
for
y being
Point of
RNS st
y in Cl Fx0 holds
||.y.|| < K + 1
then
Cl Fx0 is
compact
by A9, REAL_NS3:38;
then
ClHx is
sequentially_compact
by A7, A13, TOPMETR4:18;
hence
(MetricSpaceNorm T) | (Cl Hx) is
compact
by A12, TOPMETR4:14;
verum
end;
hence
(MetricSpaceNorm (R_NormSpace_of_ContinuousFunctions (S,T))) | H is totally_bounded
by A1, A2, A4, A5, ASCOLI:16; verum