theorem
  for L being 0_Lattice holds Bottom L = Top (L.:)
proof
  let L be 0_Lattice;
  reconsider u = Bottom L as Element of L.:;
  now
    let v be Element of L.:;
    reconsider v9 = v as Element of L;
    thus v "\/" u = Bottom L "/\" v9 by Th37
      .= u;
  end;
  hence thesis by RLSUB_2:65;
end;
