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

theorem
  Kurat7Set A = { A } \/ { Int A, Int Cl A, Int Cl Int A } \/ { Cl A, Cl
  Int A, Cl Int Cl A }
proof
  Kurat7Set A = { A } \/ { Int A, Cl A, Int Cl A, Cl Int A, Cl Int Cl A,
  Int Cl Int A } by ENUMSET1:16
    .= { A } \/ ({ Int A, Int Cl A, Int Cl Int A } \/ { Cl A, Cl Int A, Cl
  Int Cl A }) by BORSUK_5:2
    .= { A } \/ { Int A, Int Cl A, Int Cl Int A } \/ { Cl A, Cl Int A, Cl
  Int Cl A } by XBOOLE_1:4;
  hence thesis;
end;
