--- a/Doc/lib/libstdtypes.tex	Fri Jul 01 23:00:13 2005 +0000
+++ b/Doc/lib/libstdtypes.tex	Fri Jul 01 23:18:36 2005 +0000
@@ -1291,6 +1291,14 @@
 \method{symmetric_difference_update()} methods will accept any iterable
 as an argument.
 
+The design of the set types was based on lessons learned from the
+\module{sets} module.
+     
+\begin{seealso}     
+  \seemodule[comparison-to-builtin-set]{sets}{Differences between
+     the \module{sets} module and the built-in set types.}					      
+\end{seealso}
+     
 
 \subsection{Mapping Types --- class{dict} \label{typesmapping}}
 \obindex{mapping}