reserve T for TopSpace;
reserve T for non empty TopSpace;
reserve F for Subset-Family of T;
reserve T for non empty TopSpace;

theorem
  for A, B being Subset of T st A is closed_condensed holds A c= B
  implies Cl(Int(A /\ B)) = A
proof
  let A, B be Subset of T;
  assume
A1: A is closed_condensed;
  assume A c= B;
  then A /\ B = A by XBOOLE_1:28;
  hence thesis by A1,TOPS_1:def 7;
end;
