This sequent is provable. \begin{logicproof}{1} (p \imp q) \land (q \imp r) & \prem\\ \neg r \lor q & \prem\\ p \imp q & $\ande 1$ \\ q \imp r & $\ande 1$ \\ \begin{subproof} \neg r & \assum\\ \neg q & $\MT 4, 5$ \\ \neg p & $\MT 3, 6$ \\ \neg p \lor r & $\ori 7$ \end{subproof} \begin{subproof} q & \assum \\ r & $\impe 9, 4$ \\ \neg p \lor r & $\ori 10$ \end{subproof} \neg p \lor r & $\ore 2, 5-8, 9-10$ \end{logicproof}