--- a/slides/slides04.tex	Sat Dec 01 15:09:37 2018 +0000
+++ b/slides/slides04.tex	Thu Dec 06 13:15:28 2018 +0000
@@ -248,7 +248,7 @@
 
 \begin{lstlisting}[language=Scala, numbers=none, xleftmargin=-7mm]
 def is_legal(dim: Int, p: Path, x: Pos): Boolean = 
-  ......some_really_long_condition.....
+  !......some_really_long_condition.....
 \end{lstlisting}\pause