diff -r 9a3aa8c39951 -r 56bc53ba7c5b slides/slides04.tex
--- a/slides/slides04.tex	Tue Oct 20 01:01:17 2015 +0100
+++ b/slides/slides04.tex	Wed Oct 21 13:31:56 2015 +0100
@@ -359,7 +359,6 @@
 \begin{frame}[c]
 \frametitle{Subtleties}
 
-
 \begin{itemize}
 \item<1-> Can Bob write \pcode{file}?
 \item<2-> What if Bob is member of \pcode{staff}?
@@ -707,6 +706,7 @@
 
 \end{frame}
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
+
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 \begin{frame}[c]
 \frametitle{Handshakes}