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 Th86:
  A* ^^ (A+) = A+ ^^ (A*)
proof
  thus A* ^^ (A+) = A* ^^ (A |^.. 1) by Th50
    .= (A |^.. 1) ^^ (A*) by Th32
    .= A+ ^^ (A*) by Th50;
end;
