reserve S for 1-sorted,
  i for Element of NAT,
  p for FinSequence,
  X for set;

theorem Th24:
  bspace(X) is right_complementable
proof
  let x be Element of bspace(X);
  reconsider A = x as Subset of X;
  take x;
  A \+\ A = {}X by XBOOLE_1:92;
  hence thesis by Def5;
end;
