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

theorem
  Cl Int Cl KurExSet <> Int KurExSet
proof
  set A = KurExSet;
  2 in Cl Int Cl A & Int A = ]. 4, 5.[ \/ ]. 5,+infty .[ by Th18,Th27,
TOPS_1:def 1,XXREAL_1:236;
  hence thesis by XXREAL_1:223;
end;
