reserve E, x, y, X for set;
reserve A, B, C for Subset of E^omega;
reserve a, a1, a2, b for Element of E^omega;
reserve i, k, l, m, n for Nat;

theorem Th59:
  A c= A+
proof
  A |^ 1 c= A+ by Th49;
  hence thesis by FLANG_1:25;
end;
