Add xkcd image and fix \pause

talk/talk.tex

@@ -91,8 +91,8 @@
         \item Projects $P=\{p_1,\dots,p_m\}$ \pause
             \begin{itemize}
                 \setlength{\itemsep}{.7\baselineskip}
-                \item Each project $p\in P$ has associated cost \pause
+                \item Each project $p\in P$ has associated cost
-                    $c(p):P\rightarrow\mathbb{R}$
+                    $c(p):P\rightarrow\mathbb{R}$ \pause
                 \item Projects are either divisible or indivisible (discrete)
                     \pause
             \end{itemize}