diff -r 201c2c6d8696 -r 7ed2a25dd115 hws/hw09.tex
--- a/hws/hw09.tex	Tue Oct 28 06:01:00 2014 +0000
+++ b/hws/hw09.tex	Tue Oct 28 12:24:11 2014 +0000
@@ -1,25 +1,20 @@
 \documentclass{article}
-\usepackage{charter}
-\usepackage{hyperref}
-\usepackage{amssymb}
-\usepackage{amsmath}
-\usepackage{tikz}
-\usetikzlibrary{automata}
-
-\newcommand{\dn}{\stackrel{\mbox{\scriptsize def}}{=}}% for definitions
+\usepackage{../style}
+\usepackage{../graphics}
 
 \begin{document}
 
 \section*{Homework 9}
 
 \begin{enumerate}
-\item Describe what is meant by \emph{eliminating tail recursion}, when such an 
-optimization can be applied and why it is a benefit?
+\item Describe what is meant by \emph{eliminating tail
+      recursion}, when such an optimization can be applied and
+      why it is a benefit?
 
 \item It is true (I confirmed it) that
 
-\begin{center}
-if $\varnothing$ does not occur in $r$ \;\;then\;\;$L(r) \not= \{\}$
+\begin{center} if $\varnothing$ does not occur in $r$
+\;\;then\;\;$L(r) \not= \{\}$ 
 \end{center}
 
 \noindent