This sequent is not provable. Model $\mathcal{M}$:\\ \begin{minipage}{0.2\textwidth} \begin{align*} \mathcal{A} =& \; \{ a,b \}\\ P^\mathcal{M} =& \; \{ a,b \}\\ Q^\mathcal{M} =& \; \{ a \} \end{align*} \end{minipage}\\ $\mathcal{M} \models \forall x \exists y \; (P(x) \imp Q(y)), P(s)$\\ $\mathcal{M} \nmodels \exists x \forall y \; (\lnot P(x) \lor Q(y))$