--- a/slides/slides02.tex	Fri Oct 05 11:07:57 2018 +0100
+++ b/slides/slides02.tex	Mon Oct 08 11:35:04 2018 +0100
@@ -460,8 +460,8 @@
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\begin{frame}[t]
-\frametitle{Brzozowski's Algorithm (1)}
+\begin{frame}[c]
+\frametitle{\mbox{Brzozowski's Algorithm (1)}}
 
 
 \ldots{}whether a regular expression can match the empty string:
@@ -893,14 +893,14 @@
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\begin{frame}[t]
-\frametitle{What is good about this Alg.}
+\begin{frame}[c]
+\frametitle{\mbox{What is good about this Alg.}}
 
 \begin{itemize}
 \item extends to most regular expressions, for example
-\bl{$\sim r$}
+\bl{$\sim r$} (next slide)
 
-\item is easy to implement in a functional language
+\item is easy to implement in a functional language (slide after)
 
 \item the algorithm is already quite old; there is still
   work to be done to use it as a tokenizer (that is relatively new work)