This sequent is provable. \begin{logicproof}{2} \lnot q \lor \lnot p & \prem \\ \begin{subproof} q \land p & \assum \\ \begin{subproof} \lnot q & \assum \\ q & $\ande{1} 2$ \\ \bot & $\nege 3,4$ \end{subproof} \begin{subproof} \lnot p & \assum \\ p & $\ande{2} 2$ \\ \bot & $\nege 6,7$ \end{subproof} \bot & $\ore 1, 3-5, 6-8$ \end{subproof} \lnot (q \land p) & $\negi 2-9$ \end{logicproof}