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

theorem
  A? |^ k c= A*
proof
  A? |^ k = (A |^ (0, 1)) |^ k by Th79;
  hence thesis by Th32,FLANG_1:59;
end;
