--- a/hw03.tex	Wed Oct 10 08:39:24 2012 +0100
+++ b/hw03.tex	Wed Oct 10 08:50:07 2012 +0100
@@ -23,8 +23,20 @@
 $zeroable(r)$ \;if and only if\; $L(r) = \varnothing$
 \end{center}
 
+\item Define the tokens and regular expressions for a language
+consisting of numbers, left-parenthesis (, right-parenthesis ),
+identifiers and the operations $+$, $-$ and $*$. Can the following strings 
+in this language be lexed?
+
+\begin{itemize}
+\item \texttt{"}$(a + 3) * b$\texttt{"}
+\item \texttt{"}$)()++ -33$\texttt{"}
+\item \texttt{"}$(a / 3) * 3$\texttt{"}
+\end{itemize}
 \end{enumerate}
 
+In case they can, can you give the corresponding token sequences.
+
 \end{document}
 
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