let S be non empty compact TopSpace; for T being non empty MetrSpace
for f, g being Point of (MetricSpace_of_ContinuousFunctions (S,T))
for f1, g1 being Function of S,T
for e being Real st f = f1 & g = g1 & ( for t being Point of S holds dist ((f1 . t),(g1 . t)) <= e ) holds
dist (f,g) <= e
let T be non empty MetrSpace; for f, g being Point of (MetricSpace_of_ContinuousFunctions (S,T))
for f1, g1 being Function of S,T
for e being Real st f = f1 & g = g1 & ( for t being Point of S holds dist ((f1 . t),(g1 . t)) <= e ) holds
dist (f,g) <= e
let a, b be Point of (MetricSpace_of_ContinuousFunctions (S,T)); for f1, g1 being Function of S,T
for e being Real st a = f1 & b = g1 & ( for t being Point of S holds dist ((f1 . t),(g1 . t)) <= e ) holds
dist (a,b) <= e
let f1, g1 be Function of S,T; for e being Real st a = f1 & b = g1 & ( for t being Point of S holds dist ((f1 . t),(g1 . t)) <= e ) holds
dist (a,b) <= e
let e be Real; ( a = f1 & b = g1 & ( for t being Point of S holds dist ((f1 . t),(g1 . t)) <= e ) implies dist (a,b) <= e )
assume A1:
( a = f1 & b = g1 & ( for t being Point of S holds dist ((f1 . t),(g1 . t)) <= e ) )
; dist (a,b) <= e
set M = MetricSpace_of_ContinuousFunctions (S,T);
set A = ContinuousFunctions (S,T);
reconsider f = the distance of (MetricSpace_of_ContinuousFunctions (S,T)) as Function of [:(ContinuousFunctions (S,T)),(ContinuousFunctions (S,T)):],REAL ;
a in ContinuousFunctions (S,T)
;
then consider x being Function of S,(TopSpaceMetr T) such that
A3:
( a = x & x is continuous )
;
b in ContinuousFunctions (S,T)
;
then consider y being Function of S,(TopSpaceMetr T) such that
A4:
( b = y & y is continuous )
;
consider Dist1 being RealMap of S such that
A5:
( ( for t being Point of S holds Dist1 . t = dist ((In ((x . t),T)),(In ((y . t),T))) ) & f . (a,b) = upper_bound (rng Dist1) )
by Def5, A3, A4;
A6:
( rng Dist1 <> {} & rng Dist1 is bounded_above & rng Dist1 is bounded_below )
by A3, A4, A5, Th9;
hence
dist (a,b) <= e
by A6, SEQ_4:45, A5; verum