change theme to the only good beamer theme there is

doc/slides/slides.tex

 \documentclass{beamer}
 
+\usetheme{Rochester}
 \beamertemplatenavigationsymbolsempty{}
 
 \addtobeamertemplate{navigation symbols}{}{%
@@ -41,7 +42,7 @@
 \begin{frame}{Context}
   \begin{figure}
     \centering
-    \includegraphics[width=5.0cm]{figs/math.eps}
+    \includegraphics[width=3.7cm]{figs/math.eps}
     \caption{``Five Aspects of Math Artifacts'' taken from~\cite{tetra}.}
   \end{figure}