diff -r 217e66d7aeff -r 281139526cb1 hws/hw01.tex
--- a/hws/hw01.tex	Tue Oct 01 00:29:48 2019 +0100
+++ b/hws/hw01.tex	Tue Oct 01 12:22:32 2019 +0100
@@ -30,6 +30,12 @@
 %      that gives an error, but probably only 404 Not Found
 %      errors should be flagged. Can you change that?)
 
+\item {\bf (Optional)} Have a look at the catastrophic backtracking
+  programs uploaded on KEATS. Convince yourself that they really require
+  a lot of computation time. If you have similar examples in your own
+  favourite programming language, I am happy to hear about it.
+
+
 \item Read the handout of the first lecture and the handout
       about notation. Make sure you understand the concepts of
       strings and languages. In the context of the CFL-course,