let M be non empty Reflexive symmetric MetrStruct ; for a being real number
for T being Relation of the carrier of M,the carrier of M st T = dist_toler M,a & a >= 0 holds
T is Tolerance of the carrier of M
let a be real number ; for T being Relation of the carrier of M,the carrier of M st T = dist_toler M,a & a >= 0 holds
T is Tolerance of the carrier of M
let T be Relation of the carrier of M,the carrier of M; ( T = dist_toler M,a & a >= 0 implies T is Tolerance of the carrier of M )
assume that
A1:
T = dist_toler M,a
and
A2:
a >= 0
; T is Tolerance of the carrier of M
A3:
( the distance of M is symmetric & the distance of M is Reflexive )
by METRIC_1:def 7, METRIC_1:def 9;
T = low_toler the distance of M,a
by A1, Th33;
hence
T is Tolerance of the carrier of M
by A2, A3, Th18; verum