Minor edits to L13.

Lectures/L13_ModuleDecomposition/ModuleDecomposition.tex

@@ -125,6 +125,8 @@ pop & ~ & ~ & NOT\_INIT, EMPTY\\
 \hline
 front & ~ & T & NOT\_INIT, EMPTY\\
 \hline
+size & ~ & integer & NOT\_INIT\\
+\hline
 isempty & ~ & boolean & NOT\_INIT\\
 \hline
 isfull & ~ & boolean & NOT\_INIT\\
@@ -282,8 +284,8 @@ their shared secret?
 \frametitle{Questions}
 
 \begin{itemize}
-\item How to define the structure of a modular system?
-\item What are the desirable properties of that structure?
+\item What relationships have we discussed between modules?
+\item Are there desirable properties for these relations?
 \end{itemize}
 
 \end{frame}
@@ -331,6 +333,8 @@ r^{+} M_j$$
 \includegraphics[width=1.0\textwidth]{GraphAndDAG.png}
 \end{center}
 
+\structure{Why do we prefer the uses relation to be a DAG?}
+
 \end{frame}
 
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