let S be RealNormSpace-Sequence; for s being set holds
( proj (In (s,(dom S))) is Lipschitzian LinearOperator of (product S),(S . (In (s,(dom S)))) & ex LP being Point of (R_NormSpace_of_BoundedLinearOperators ((product S),(S . (In (s,(dom S)))))) st
( LP = proj (In (s,(dom S))) & ||.LP.|| <= 1 ) )
let s be set ; ( proj (In (s,(dom S))) is Lipschitzian LinearOperator of (product S),(S . (In (s,(dom S)))) & ex LP being Point of (R_NormSpace_of_BoundedLinearOperators ((product S),(S . (In (s,(dom S)))))) st
( LP = proj (In (s,(dom S))) & ||.LP.|| <= 1 ) )
set L1 = proj (In (s,(dom S)));
set F = S . (In (s,(dom S)));
set E = product S;
A1:
proj (In (s,(dom S))) is additive
by NDIFF_5:35;
for x being VECTOR of (product S)
for a being Real holds (proj (In (s,(dom S)))) . (a * x) = a * ((proj (In (s,(dom S)))) . x)
by NDIFF_5:40;
then reconsider L1 = proj (In (s,(dom S))) as LinearOperator of (product S),(S . (In (s,(dom S)))) by A1, LOPBAN_1:def 5;
set K = 1;
for x being VECTOR of (product S) holds ||.(L1 . x).|| <= 1 * ||.x.||
by NDIFF_5:31;
hence A3:
proj (In (s,(dom S))) is Lipschitzian LinearOperator of (product S),(S . (In (s,(dom S))))
by LOPBAN_1:def 8; ex LP being Point of (R_NormSpace_of_BoundedLinearOperators ((product S),(S . (In (s,(dom S)))))) st
( LP = proj (In (s,(dom S))) & ||.LP.|| <= 1 )
then reconsider LP = L1 as Point of (R_NormSpace_of_BoundedLinearOperators ((product S),(S . (In (s,(dom S)))))) by LOPBAN_1:def 9;
take
LP
; ( LP = proj (In (s,(dom S))) & ||.LP.|| <= 1 )
thus
LP = proj (In (s,(dom S)))
; ||.LP.|| <= 1
A5:
for x being Real st x in PreNorms (modetrans (LP,(product S),(S . (In (s,(dom S)))))) holds
x <= 1
proof
let x be
Real;
( x in PreNorms (modetrans (LP,(product S),(S . (In (s,(dom S)))))) implies x <= 1 )
assume
x in PreNorms (modetrans (LP,(product S),(S . (In (s,(dom S))))))
;
x <= 1
then consider y being
VECTOR of
(product S) such that A6:
(
x = ||.((modetrans (LP,(product S),(S . (In (s,(dom S)))))) . y).|| &
||.y.|| <= 1 )
;
A7:
||.(L1 . y).|| <= 1
* ||.y.||
by NDIFF_5:31;
LP = modetrans (
LP,
(product S),
(S . (In (s,(dom S)))))
by A3, LOPBAN_1:29;
hence
x <= 1
by A6, A7, XXREAL_0:2;
verum
end;
reconsider LP0 = LP as Element of BoundedLinearOperators ((product S),(S . (In (s,(dom S))))) ;
A8:
PreNorms (modetrans (LP,(product S),(S . (In (s,(dom S)))))) is bounded_above
now not upper_bound (PreNorms (modetrans (LP,(product S),(S . (In (s,(dom S))))))) > 1assume A9:
upper_bound (PreNorms (modetrans (LP,(product S),(S . (In (s,(dom S))))))) > 1
;
contradictionset dif =
(upper_bound (PreNorms (modetrans (LP,(product S),(S . (In (s,(dom S)))))))) - 1;
(upper_bound (PreNorms (modetrans (LP,(product S),(S . (In (s,(dom S)))))))) - 1
> 0
by A9, XREAL_1:50;
then
ex
w being
Real st
(
w in PreNorms (modetrans (LP,(product S),(S . (In (s,(dom S)))))) &
(upper_bound (PreNorms (modetrans (LP,(product S),(S . (In (s,(dom S)))))))) - ((upper_bound (PreNorms (modetrans (LP,(product S),(S . (In (s,(dom S)))))))) - 1) < w )
by A8, SEQ_4:def 1;
hence
contradiction
by A5;
verum end;
hence
||.LP.|| <= 1
by LOPBAN_1:def 13; verum