2/122
\begin{frame}{Looking Back}
\structure{Last Lecture:}
\medskip

\begin{goal}{}
The following statements are equivalent:
\medskip
\begin{itemize}\setlength{\itemsep}{2ex}
\item There is a \alert{DFA} $M$ with $L(M) = L$.
\item There is an \alert{NFA} $M$ with $L(M) = L$.
\item There is a \alert{right linear grammar} $G$ with $L(G) = L$.
\item There is a \alert{left linear grammar} $G$ with $L(G) = L$.
\item There is a \alert{regular expression} $r$ with $L(r) = L$.
\end{itemize}
\medskip
\end{goal}
\end{frame}