\begin{frame} \frametitle{Example} \begin{exampleblock}{} Use $\bot_e$ to prove \quad$\neg p \vee q \;\vdash\; p \to q$\quad! \medskip \begin{tikzpicture} \naturaldeduction{ \mpause[1]{ \proofstep{$\neg p \vee q$}{premise}; } \mpause{ \proofbox{ \mpause{ \proofstep{$p$}{assumption}; } \mpause{ \proofbox{ \mpause{ \proofstep{$\neg p$}{assumption}; } \mpause{ \proofstep{$\bot$}{$\neg_e$ 2,3}; } \mpause{ \proofstep{$q$}{$\bot_e$ 4}; } } } \mpause{ \proofbox{ \mpause{ \proofstep{$q$}{assumption}; } } } \mpause{ \proofstep{$q$}{$\vee_e$ 1,\;3--5,\;6--6}; } } } \mpause{ \proofstep{$p\to q$}{$\to_i$ 2--7}; } } \end{tikzpicture} \end{exampleblock} \end{frame}