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

theorem
  card Kurat7Set KurExSet = 7
proof
  set A = KurExSet;
  A, Int A, Cl A, Int Cl A, Cl Int A, Cl Int Cl A, Int Cl Int A
  are_mutually_distinct by Th54;
  hence thesis by BORSUK_5:4;
end;
