
theorem Th1:
  for T be non empty MetrSpace,
      A be Subset of T holds A c= Cl A
proof
  let T be non empty MetrSpace,
      A be Subset of T;
  consider Z being Subset of TopSpaceMetr T such that
A1: Z = A & Cl A = Cl Z by ASCOLI:def 1;
  thus thesis by A1,PRE_TOPC:18;
end;
