--- a/query-languages.tex
+++ b/query-languages.tex
@@ -233,19 +233,19 @@
 
 \end{frame}
 
-\begin{frame}[fragile]{Handling Missing Revisions}
-  If you don't know if a given revision is present, then use:
-  \begin{itemize}
-  \item \cmd{present(set)}: prevents lookup errors if a revision in
-    set is not found. Used like
-\begin{lstlisting}
-$ hg log -r "head() and (present('bad'):: - present('fix')::)"
-\end{lstlisting}
-    where bad is a known buggy changeset and fix is a bugfix. Without
-    the use of \cmd{present()}, an error would be raised if the bugfix
-    is not yet in the repository.
-  \end{itemize}
-\end{frame}
+%\begin{frame}[fragile]{Handling Missing Revisions}
+%  If you don't know if a given revision is present, then use:
+%  \begin{itemize}
+%  \item \cmd{present(set)}: prevents lookup errors if a revision in
+%    set is not found. Used like
+%\begin{lstlisting}
+%$ hg log -r "head() and (present('bad'):: - present('fix')::)"
+%\end{lstlisting}
+%    where bad is a known buggy changeset and fix is a bugfix. Without
+%    the use of \cmd{present()}, an error would be raised if the bugfix
+%    is not yet in the repository.
+%  \end{itemize}
+%\end{frame}
 
 \begin{frame}{Final Touches on Your Query}
   Trimming, cutting, manipulating the set: