diff -r 4123344e6915 -r a75f9c9d8f94 handouts/ho02.tex
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/handouts/ho02.tex	Fri Oct 04 15:40:10 2013 +0100
@@ -0,0 +1,74 @@
+\documentclass{article}
+\usepackage{charter}
+\usepackage{hyperref}
+\usepackage{amssymb}
+\usepackage{amsmath}
+\usepackage[T1]{fontenc}
+\usepackage{listings}
+\usepackage{xcolor}
+
+\newcommand{\dn}{\stackrel{\mbox{\scriptsize def}}{=}}%
+
+\definecolor{javared}{rgb}{0.6,0,0} % for strings
+\definecolor{javagreen}{rgb}{0.25,0.5,0.35} % comments
+\definecolor{javapurple}{rgb}{0.5,0,0.35} % keywords
+\definecolor{javadocblue}{rgb}{0.25,0.35,0.75} % javadoc
+
+\lstdefinelanguage{scala}{
+  morekeywords={abstract,case,catch,class,def,%
+    do,else,extends,false,final,finally,%
+    for,if,implicit,import,match,mixin,%
+    new,null,object,override,package,%
+    private,protected,requires,return,sealed,%
+    super,this,throw,trait,true,try,%
+    type,val,var,while,with,yield},
+  otherkeywords={=>,<-,<\%,<:,>:,\#,@},
+  sensitive=true,
+  morecomment=[l]{//},
+  morecomment=[n]{/*}{*/},
+  morestring=[b]",
+  morestring=[b]',
+  morestring=[b]"""
+}
+
+\lstset{language=Scala,
+	basicstyle=\ttfamily,
+	keywordstyle=\color{javapurple}\bfseries,
+	stringstyle=\color{javagreen},
+	commentstyle=\color{javagreen},
+	morecomment=[s][\color{javadocblue}]{/**}{*/},
+	numbers=left,
+	numberstyle=\tiny\color{black},
+	stepnumber=1,
+	numbersep=10pt,
+	tabsize=2,
+	showspaces=false,
+	showstringspaces=false}
+	
+\begin{document}
+
+\section*{Handout 2}
+
+Having specified what problem our matching algorithm, $match$, is supposed to solve, namely
+for a given regular expression $r$ and string $s$ answer $true$ if and only if
+
+\[
+s \in L(r)
+\]
+
+\noindent
+Clearly we cannot use the function $L$ directly in order to solve this problem, because in general
+the set of strings $L$ returns is infinite (recall what $L(a^*)$ is). In such cases there is no algorithm
+then can test exhaustively, whether a string is member of this set.
+
+The algorithm we define below consists of two parts. One is the function $nullable$ which takes a
+regular expression as argument and decides whether it can match the empty string. This can be easily 
+defined recursively as follows:
+
+
+\end{document}
+
+%%% Local Variables: 
+%%% mode: latex
+%%% TeX-master: t
+%%% End: