reserve T for non empty TopSpace;
reserve A for Subset of T;

theorem Th45:
  Int Cl Int KurExSet <> Int Cl KurExSet
proof
  set A = KurExSet;
  not 3 in Int Cl Int A by Th25,XXREAL_1:235;
  hence thesis by Th26,XXREAL_1:235;
end;
