tweaks

book.tex

@@ -5320,7 +5320,7 @@ Because the two closures came from the same \key{lambda}, they share
 the same code but differ in the values for free variable \code{x}.
 
 \begin{figure}[tbp]
-\centering \includegraphics[width=0.7\textwidth]{closures}
+\centering \includegraphics[width=0.6\textwidth]{closures}
 \caption{Example closure representation for the \key{lambda}'s
   in Figure~\ref{fig:lexical-scoping}.}
 \label{fig:closures}