--- a/coursework/cw02.tex	Sun Nov 10 09:27:01 2013 +0000
+++ b/coursework/cw02.tex	Mon Nov 11 00:34:14 2013 +0000
@@ -133,10 +133,30 @@
 \subsection*{Question 3 (marked with 1\%)}
 
 Write a program in the WHILE programming language that prints out all prime numbers between
-0 and a fixed number (say 100). Take the grammar of this language from the lectures. As another 
-guidance have a look at the Fibonacci program
-and ``three-nested-loops'' program shown below. For example, printing a variable \texttt{x} in the 
-WHILE language can be done by using the command \mbox{\texttt{write x}}. 
+0 and a fixed number (say 100). A partial grammar of the WHILE language is given below. 
+
+\begin{center}
+\begin{tabular}{@{}lcl@{}}
+\textit{Stmt} & $\rightarrow$ &  $\texttt{skip}$\\
+              & $|$ & \textit{Id}\;\texttt{:=}\;\textit{AExp}\\
+              & $|$ & \texttt{if}\; \textit{BExp} \;\texttt{then}\; \textit{Block} \;\texttt{else}\; \textit{Block}\\
+              & $|$ & \texttt{while}\; \textit{BExp} \;\texttt{do}\; \textit{Block}\\
+              & $|$ & \texttt{read}\;\textit{Id}\\
+              & $|$ & \texttt{write}\;\textit{Id}\\
+              & $|$ & \texttt{write}\;\textit{String}\medskip\\
+\textit{Stmts} & $\rightarrow$ &  \textit{Stmt} \;\texttt{;}\; \textit{Stmts}\\
+              & $|$ & \textit{Stmt}\medskip\\
+\textit{Block} & $\rightarrow$ &  \texttt{\{}\,\textit{Stmts}\,\texttt{\}}\\
+                & $|$ & \textit{Stmt}\medskip\\
+\textit{AExp} & $\rightarrow$ & \ldots\\
+\textit{BExp} & $\rightarrow$ & \ldots\\
+\end{tabular}
+\end{center}
+
+\noindent
+As another guidance for your program have a look at the Fibonacci program
+and ``three-nested-loops'' program shown below in Figures \ref{fib} and \ref{loop}. 
+
 
 \begin{figure}[h]
 \begin{center}