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
  k <= l implies A* ^^ (A |^ (k, l)) = A |^.. k
proof
  assume k <= l;
  then (A |^.. 0) ^^ (A |^ (k, l)) = A |^.. (0 + k) by Th33;
  hence thesis by Th11;
end;
