\begin{frame} \frametitle{Truth Values} \begin{goal}{} In propositional logic, the \emph{truth value} of a formula is determined by a \emph{truth assignment} of the variables in the formula. \end{goal} \pause\smallskip \begin{exampleblock}{} For example, assigning \begin{itemize} \item to $p$ and $q$ the truth value $\T$, and \item to $r$ the truth value $\F$, \end{itemize} determines the truth value of the formula $p \vee \neg q \to r$. \end{exampleblock} \pause\bigskip The truth value of a formula can, for example, be computed via: \begin{itemize} \item the \emph{parse tree}, or \item by making a \emph{truth table}. \end{itemize} \end{frame}