
diff -r 629ebe8b7bbd -r a48605bdf467 coursework/cw01.tex
--- a/coursework/cw01.tex	Mon Oct 01 01:11:42 2018 +0100
+++ b/coursework/cw01.tex	Mon Oct 01 14:04:48 2018 +0100
@@ -11,7 +11,7 @@
 \section*{Coursework 1 (Strand 1)}
 
 This coursework is worth 4\% and is due on 12 October at
-16:00. You are asked to implement a regular expression matcher
+18:00. You are asked to implement a regular expression matcher
 and submit a document containing the answers for the questions
 below. You can do the implementation in any programming
 language you like, but you need to submit the source code with
@@ -62,12 +62,15 @@
 $0$. In the case of $r^{\{n,m\}}$ you can also assume $0 \le n \le m$.\bigskip
 
 \noindent {\bf Important!} Your implementation should have explicit
-cases for the basic regular expressions, but also for explicit cases for
-the extended regular expressions. That means do not treat the extended
-regular expressions by just translating them into the basic ones. See
-also Question 3, where you are asked to explicitly give the rules for
-\textit{nullable} and \textit{der} for the extended regular
-expressions.\newpage
+case classes  for the basic regular expressions, but also explicit case
+classes for
+the extended regular expressions.\footnote{Please call them
+  \code{RANGE}, \code{PLUS}, \code{OPTIONAL}, \code{NTIMES},
+  \code{UPTO}, \code{FROM}, \code{BETWEEN}, \code{NOT} or something
+  like that.} That means do not treat the extended regular expressions
+by just translating them into the basic ones. See also Question 3,
+where you are asked to explicitly give the rules for \textit{nullable}
+and \textit{der} for the extended regular expressions.\medskip
 
 \noindent
 The meanings of the extended regular expressions are
@@ -110,16 +113,18 @@
 
 \subsection*{Question 2 (Unmarked)}
 
-In which programming languages have you written a program (like spent
-at least a day working on the program)?
+Can you please list all programming languages in which you have
+already written programs (like spent at least a good working day
+working on the program)?  This is just for my curiosity to estimate
+what your background is.
 
 \subsection*{Question 3}
 
 From the
 lectures you have seen the definitions for the functions
 \textit{nullable} and \textit{der} for the basic regular
-expressions. Implement the rules for the extended regular
-expressions:
+expressions. Implement and write down rules for the extended
+regular expressions:
 
 \begin{center}
 \begin{tabular}{@ {}l@ {\hspace{2mm}}c@ {\hspace{2mm}}l@ {}}
@@ -192,11 +197,11 @@
 \end{center}
 
 \noindent
-the latter is useful for matching any string (for example
+The latter is useful for matching any string (for example
 by using $\textit{ALL}^*$). In order to avoid having an explicit constructor
 for each case, we can generalise all these cases and introduce a single
 constructor $\textit{CFUN}(f)$ where $f$ is a function from characters
-to a boolean. The idea is that the function $f$ determines which character(s)
+to booleans. The idea is that the function $f$ determines which character(s)
 are matched, namely those where $f$ returns \texttt{true}.
 In this question implement \textit{CFUN} and define
 
@@ -217,6 +222,11 @@
 \end{tabular}
 \end{center}
 
+\noindent
+You can either add the constructor $CFUN$ to your implementation in
+Question 3, or you can implement this questions first
+and then use $CFUN$ instead of \code{RANGE} and \code{CHAR} in Question 3.
+
 
 \subsection*{Question 5}
 
@@ -231,7 +241,7 @@
 ([a\mbox{-}z0\mbox{-}9\_\,.-]^+)\cdot @\cdot ([a\mbox{-}z0\mbox{-}9\,.-]^+)\cdot .\cdot ([a\mbox{-}z\,.]^{\{2,6\}})
 \]
 
-\noindent and calculate the derivative according to your email
+\noindent and calculate the derivative according to your own email
 address. When calculating the derivative, simplify all regular
 expressions as much as possible by applying the
 following 7 simplification rules:
@@ -251,9 +261,11 @@
 \noindent Write down your simplified derivative in a readable
 notation using parentheses where necessary. That means you
 should use the infix notation $+$, $\cdot$, $^*$ and so on,
-instead of code.\bigskip
- 
-\noindent
+instead of raw code.\bigskip
+
+
+\subsection*{Question 6}
+
 Implement the simplification rules in your regular expression matcher.
 Consider the regular expression $/ \cdot * \cdot
 (\sim{}(\textit{ALL}^* \cdot * \cdot / \cdot \textit{ALL}^*)) \cdot *
@@ -267,7 +279,7 @@
 \item \texttt{"/*test/*test*/"}
 \end{enumerate}
 
-\subsection*{Question 6}
+\subsection*{Question 7}
 
 Let $r_1$ be the regular expression $a\cdot a\cdot a$ and $r_2$ be
 $(a^{\{19,19\}}) \cdot (a^?)$.  Decide whether the following three




