reserve T for non empty TopSpace,
  A, B for Subset of T,
  F, G for Subset-Family of T;

theorem
  for T being discrete non empty TopSpace holds T is separable iff T is
  countable
proof
  let T be discrete non empty TopSpace;
  T is separable iff card [#]T c= omega by Th10;
  hence thesis by TOPGEN_1:2;
end;
