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\begin{frame}[t]
\frametitle{Quantifiers}

\vspace{-1ex}
Instead of $x$ is green' we now want to say:
\begin{itemize}
\item somebody is green', or
\item everybody is green'.
\end{itemize}
\pause

\begin{goal}{Existential quantifier}
\vspace{-1ex}
\begin{talign}
\myex{x}{\phi}
\end{talign}
\vspace{-3ex}

means: there exists some $x$ such that the formula $\phi$ is true.
\end{goal}
\pause

\begin{exampleblock}{}
\begin{malign}
\end{malign}
\end{exampleblock}
\pause

\begin{goal}{Universal quantifier}
\vspace{-1ex}
\begin{talign}
\myall{x}{\phi}
\end{talign}
\vspace{-3ex}

means: for every $x$ the formula $\phi$ is true.
\end{goal}
\pause

\begin{exampleblock}{}
\begin{malign}
`