Add a pause

VL1.tex

@@ -401,6 +401,7 @@ listLen :: [Integer] -> Integer
 listLen [] = 0
 listLen (x:xs) = 1 + listLen xs
 \end{lstlisting}
+\pause
 We can also nest pattern matching:
 \begin{lstlisting}
 sumEveryTwo :: [Integer] -> [Integer]