let F1, F2 be Function of [:(ContinuousFunctions (S,T)),(ContinuousFunctions (S,T)):],REAL; ( ( for f, g being Function of S,(TopSpaceMetr T) st f in ContinuousFunctions (S,T) & g in ContinuousFunctions (S,T) holds
ex Dist being RealMap of S st
( ( for x being Point of S holds Dist . x = dist ((In ((f . x),T)),(In ((g . x),T))) ) & F1 . (f,g) = upper_bound (rng Dist) ) ) & ( for f, g being Function of S,(TopSpaceMetr T) st f in ContinuousFunctions (S,T) & g in ContinuousFunctions (S,T) holds
ex Dist being RealMap of S st
( ( for x being Point of S holds Dist . x = dist ((In ((f . x),T)),(In ((g . x),T))) ) & F2 . (f,g) = upper_bound (rng Dist) ) ) implies F1 = F2 )
assume that
A1:
for f, g being Function of S,(TopSpaceMetr T) st f in ContinuousFunctions (S,T) & g in ContinuousFunctions (S,T) holds
ex Dist being RealMap of S st
( ( for x being Point of S holds Dist . x = dist ((In ((f . x),T)),(In ((g . x),T))) ) & F1 . (f,g) = upper_bound (rng Dist) )
and
A2:
for f, g being Function of S,(TopSpaceMetr T) st f in ContinuousFunctions (S,T) & g in ContinuousFunctions (S,T) holds
ex Dist being RealMap of S st
( ( for x being Point of S holds Dist . x = dist ((In ((f . x),T)),(In ((g . x),T))) ) & F2 . (f,g) = upper_bound (rng Dist) )
; F1 = F2
set H = ContinuousFunctions (S,T);
for x, y being set st x in ContinuousFunctions (S,T) & y in ContinuousFunctions (S,T) holds
F1 . (x,y) = F2 . (x,y)
proof
let x,
y be
set ;
( x in ContinuousFunctions (S,T) & y in ContinuousFunctions (S,T) implies F1 . (x,y) = F2 . (x,y) )
assume A3:
(
x in ContinuousFunctions (
S,
T) &
y in ContinuousFunctions (
S,
T) )
;
F1 . (x,y) = F2 . (x,y)
then consider f being
Function of
S,
(TopSpaceMetr T) such that A4:
(
x = f &
f is
continuous )
;
consider g being
Function of
S,
(TopSpaceMetr T) such that A5:
(
y = g &
g is
continuous )
by A3;
consider Dist1 being
RealMap of
S such that A6:
( ( for
x being
Point of
S holds
Dist1 . x = dist (
(In ((f . x),T)),
(In ((g . x),T))) ) &
F1 . (
f,
g)
= upper_bound (rng Dist1) )
by A1, A3, A4, A5;
consider Dist2 being
RealMap of
S such that A7:
( ( for
x being
Point of
S holds
Dist2 . x = dist (
(In ((f . x),T)),
(In ((g . x),T))) ) &
F2 . (
f,
g)
= upper_bound (rng Dist2) )
by A2, A3, A4, A5;
for
t being
Point of
S holds
Dist1 . t = Dist2 . t
hence
F1 . (
x,
y)
= F2 . (
x,
y)
by A4, A5, A6, A7, FUNCT_2:63;
verum
end;
hence
F1 = F2
by BINOP_1:1; verum