diff -r 36799f7b9702 -r 5990e03b2ba8 slides/slides06.tex
--- a/slides/slides06.tex	Fri Oct 31 19:26:11 2025 +0000
+++ b/slides/slides06.tex	Sat Nov 01 04:59:23 2025 +0000
@@ -61,28 +61,61 @@
 \end{frame}
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%     
 
+
 \begin{frame}[t,fragile]
-\begin{mybox3}{}
-  In CW2, be careful with the order of defining regular expressions:
+\begin{minipage}{1.1\textwidth}
+ \begin{mybox3}{}
+   Why the hell did we bother for 4 long weeks with a worse-than-cubic
+   lexing algorithm for regular expressions, given the CYK-algorithm
+   can decide in cubic time whether a string is matched by a context 
+   free grammar? Is the lecturer insane?
+ \end{mybox3}
+\end{minipage}\bigskip
 
-\begin{verbatim}
-val COMMENT : Rexp = ... ~ EOL
-val EOL : Rexp = "\r\n" |  "\n"
-\end{verbatim}
-\end{mybox3}
+\begin{itemize}
+\item Yes, if we are only after string matching. But we are after lexing where
+  we need POSIX matching 
+  and calculate POSIX values. You cannot do this with any of the CFG-algorithms.
+\item Also it is not so easy to include extended regular expressions like $\sim{}r$
+and $r^{\{n\}}$. 
+\end{itemize}
+\end{frame}
+
+\begin{frame}[t,fragile]
+\begin{minipage}{1.1\textwidth}
+ \begin{mybox3}{}
+   Why the hell did we bother for 4 long weeks with a lexing algorithm 
+   generating tokens, given the lecturer explains the parsing algorithm using 
+   strings as input? Has the lecturer gone insane?
+ \end{mybox3}
+\end{minipage}\bigskip
+
 \end{frame}
 
 
-\begin{frame}[t,fragile]
-\begin{mybox3}{}
-  In CW2, what is the derivative of RECD?
-
-\begin{center}
-\bl{$der\;c\;RECD(l, r) \;\;\dn\;\; ???$}
-\end{center}  
-\end{mybox3}
-\end{frame}
-
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%    
+%\begin{frame}[t,fragile]
+%\begin{mybox3}{}
+%  In CW2, be careful with the order of defining regular expressions:
+%
+%\begin{verbatim}
+%val COMMENT : Rexp = ... ~ EOL
+%val EOL : Rexp = "\r\n" |  "\n"
+%\end{verbatim}
+%\end{mybox3}
+%\end{frame}
+%
+%
+%\begin{frame}[t,fragile]
+%\begin{mybox3}{}
+%  In CW2, what is the derivative of RECD?
+%
+%\begin{center}
+%\bl{$der\;c\;RECD(l, r) \;\;\dn\;\; ???$}
+%\end{center}  
+%\end{mybox3}
+%\end{frame}
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%