knapp proof-knapp proof--2knapp proof--4knapp proof--5knapp proof--6knapp proof--7knapp proof--8knapp proof--9knapp proof--10knapp proof--11knapp proof--12knapp proof--13knapp proof--14knapp proof--15knapp proof--16knapp proof--17knapp proof--18knapp proof--19knapp proof--20knapp proof--21