let a, b be real number ; :: thesis: for s being Real_Sequence st rng s c= [.a,b.] holds
s is sequence of (Closed-Interval-MSpace a,b)
let s be Real_Sequence; :: thesis: ( rng s c= [.a,b.] implies s is sequence of (Closed-Interval-MSpace a,b) )
assume A1:
rng s c= [.a,b.]
; :: thesis: s is sequence of (Closed-Interval-MSpace a,b)
A2:
dom s = NAT
by FUNCT_2:def 1;
then A3:
s . 0 in rng s
by FUNCT_1:def 5;
reconsider t = s . 0 as Real ;
( a <= t & t <= b )
by A1, A3, XXREAL_1:1;
then
the carrier of (Closed-Interval-MSpace a,b) = [.a,b.]
by TOPMETR:14, XXREAL_0:2;
hence
s is sequence of (Closed-Interval-MSpace a,b)
by A1, A2, FUNCT_2:4; :: thesis: verum