diff -r 1b718d6065c2 -r 9b1c15c3eb6f slides/slides01.tex
--- a/slides/slides01.tex	Tue Jul 30 23:44:56 2019 +0100
+++ b/slides/slides01.tex	Wed Sep 25 11:24:34 2019 +0100
@@ -202,7 +202,7 @@
 \begin{itemize}
 \item \bl{$(a^{?\{n\}}) \cdot a^{\{n\}}$}
 \item \bl{$(a^*)^*\cdot b$}
-\item \bl{$([a$\,-\,$z]^+)^*$}
+\item \bl{$([a-z]^+)^*$}
 \item \bl{$(a + a \cdot a)^*$}
 \item \bl{$(a + a^?)^*$}
 \end{itemize}