theorem Th16:
  for m,n being non zero Nat st m <= n holds LP<=6n+1(m) <= LP<=6n+1(n)
  proof
    let m,n be non zero Nat;
    assume m <= n;
    then <=6n+1(m) c= <=6n+1(n) by Th9;
    hence thesis by XXREAL_2:59,XBOOLE_1:26;
  end;
