theorem Seqs1:
  for n being Nat holds Reci-Sqf.n >= 0
  proof
    let n be Nat;
    per cases;
    suppose n = 0;
      hence thesis by MySumDef;
    end;
    suppose n <> 0; then
      reconsider nn = n as non zero Nat;
      Reci-Sqf.n = 1 / SquarefreePart nn by MySumDef;
      hence thesis;
    end;
  end;
