let T be non empty MetrSpace; :: thesis: for A being Subset of T holds A c= Cl A
let A be Subset of T; :: thesis: A c= Cl A
consider Z being Subset of (TopSpaceMetr T) such that
A1: ( Z = A & Cl A = Cl Z ) by ASCOLI:def 1;
thus A c= Cl A by A1, PRE_TOPC:18; :: thesis: verum