diff -r bd25d9f9d9dc -r 34775227c84f coursework/cw01.tex
--- a/coursework/cw01.tex	Sat Sep 23 14:19:09 2017 +0100
+++ b/coursework/cw01.tex	Sat Sep 23 19:32:21 2017 +0100
@@ -29,6 +29,43 @@
 
 \subsection*{Task}
 
+A Unix directory might look as follows:
+
+\begin{center}
+\begin{verbatim}
+$ ls -ld . * */*
+drwxr-xr-x 1 ping staff  32768 Apr  2 2010 .
+-rw----r-- 1 ping students  31359 Jul 24 2011 manual.txt
+-r--rw--w- 1 bob students   4359 Jul 24 2011 report.txt
+-rwsr--r-x 1 bob students 141359 Jun  1 2013 microedit
+dr--r-xr-x 1 bob staff  32768 Jul 23 2011 src
+-rw-r--r-- 1 bob staff  81359 Feb 28 2012 src/code.c
+-r--rw---- 1 emma students    959 Jan 23 2012 src/code.h
+\end{verbatim}
+\end{center}
+
+with group memberships assigned as follows:
+\begin{center}
+\begin{tabular}{ll}
+Members of group staff: & ping, bob, emma\\ 
+Members of group students: & emma\\
+\end{tabular}
+\end{center}
+
+The file microedit is a text editor, which allows its users to open, edit and 
+save files. Note carefully that microedit has set its setuid flag. 
+Fill in the access control matrix below that shows for each of the above five files, 
+whether ping, bob, or emma are able to obtain the right to read (R) or replace (W) its 
+contents using the editor microedit.\bigskip
+
+\begin{center}
+\begin{tabular}{r|c|c|c|c|c}
+        & manual.txt & report.txt & microedit & src/code.c & src/code.h \\\hline
+ping & & & & &\\\hline
+bob & & & & &\\\hline
+emma   & & & & &\\
+\end{tabular}
+\end{center}
 
 
 \end{document}