--- a/handouts/ho09.tex	Tue Nov 25 15:54:28 2014 +0000
+++ b/handouts/ho09.tex	Wed Nov 26 10:15:43 2014 +0000
@@ -1,14 +1,25 @@
 \documentclass{article}
 \usepackage{../style}
 \usepackage{../langs}
-\usetikzlibrary{patterns,decorations.pathreplacing}
 
 \begin{document}
 
-\section*{Handout 9 (Zero-Knowledge Proofs)}
+\section*{Handout 9 (Static Analysis)}
+
+If we want to improve the safety and security of our programs,
+we need a more principled approach to programming.
+
 
-Paper about breaking HiTag2 (gave hash, but cannot verify
-it without giving the paper)
+\noindent What would be missing in comparison with real
+(low-level machine) code? Well, the numbers we assume to be
+arbitrary precision, which is not the case in real code. There
+basic number formats have a rang and might over-run or
+under-run from this range. Our assumption about variables,
+does not correspond to actual registers, which are only 
+limited on real hardware. Obviously, real code has richer
+operations than just addition, multiplication and equality.
+But this are not really essential limitations of our simple
+examples.
 
 \end{document}