Binary file coursework/cw03.pdf has changed

--- a/coursework/cw03.tex	Wed Nov 06 17:09:58 2019 +0000
+++ b/coursework/cw03.tex	Wed Nov 06 21:52:42 2019 +0000
@@ -31,11 +31,12 @@
 
 \begin{itemize}
 \item arithmetic expressions (with the operations from the
-  previous coursework, such as \pcode{+}, \pcode{*} and so on)
-\item boolean expressions (such as \pcode{<}, \code{!=} and 
-  so on)
-\item single statements (such as \pcode{skip}, assignments, \pcode{if}s,
-  \pcode{while}-loops and so on)
+  previous coursework, that is \pcode{+}, \pcode{-}, \pcode{*},
+  \pcode{/} and \pcode{\%})
+\item boolean expressions (with the operations \pcode{==}, \pcode{<}, \pcode{>},
+  \code{!=}, \pcode{&&}, \pcode{||}, \pcode{true} and \pcode{false})
+\item single statements (that is \pcode{skip}, assignments, \pcode{if}s,
+  \pcode{while}-loops, \pcode{read} and \pcode{write})
 \item compound statements separated by semicolons
 \item blocks which are enclosed in curly parentheses
 \end{itemize}
@@ -78,6 +79,7 @@
 case object True extends BExp
 case object False extends BExp
 case class Bop(o: String, a1: AExp, a2: AExp) extends BExp
+case class Lop(o: String, b1: BExp, b2: BExp) extends BExp
 \end{lstlisting}
 \caption{The datatype for parse trees in Scala.\label{trees}}
 \end{figure}

Binary file handouts/ho05.pdf has changed

--- a/handouts/ho05.tex	Wed Nov 06 17:09:58 2019 +0000
+++ b/handouts/ho05.tex	Wed Nov 06 21:52:42 2019 +0000
@@ -17,7 +17,7 @@
 While regular expressions are very useful for lexing and for recognising
 many patterns in strings (like email addresses), they have their
 limitations. For example there is no regular expression that can
-recognise the language $a^nb^n$ (where you have strings with $n$ $a$'s
+recognise the language $a^nb^n$ (where you have strings starting with $n$ $a$'s
 followed by the same amount of $b$'s). Another example for which there
 exists no regular expression is the language of well-parenthesised
 expressions. In languages like Lisp, which use parentheses rather
@@ -66,7 +66,7 @@
 the ``words'' appear in. For example ambiguity issues like
 
 \begin{center}
-\tt Time flies like an arrow; fruit flies like bananas.
+\tt Time flies like an arrow. Fruit flies like bananas.
 \end{center}  
 
 \noindent
@@ -466,14 +466,14 @@
 The following grammar is in Chomsky normalform:
 
 \begin{plstx}[margin=1cm]
-  : \meta{S\/} ::= \meta{N}\cdot \meta{P}\\
-  : \meta{P\/} ::= \meta{V}\cdot \meta{N}\\
-  : \meta{N\/} ::= \meta{N}\cdot \meta{N}\\
-  : \meta{N\/} ::= \meta{A}\cdot \meta{N}\\
-  : \meta{N\/} ::= \texttt{student} | \texttt{trainer} | \texttt{team} 
-                   | \texttt{trains}\\
-  : \meta{V\/} ::= \texttt{trains} | \texttt{team}\\
-  : \meta{A\/} ::= \texttt{The} | \texttt{the}\\
+  : \meta{S} ::= \meta{N}\cdot \meta{P}\\
+  : \meta{P} ::= \meta{V}\cdot \meta{N}\\
+  : \meta{N} ::= \meta{N}\cdot \meta{N}\\
+  : \meta{N} ::= \meta{A}\cdot \meta{N}\\
+  : \meta{N} ::= \texttt{student} | \texttt{trainer} | \texttt{team} 
+                | \texttt{trains}\\
+  : \meta{V} ::= \texttt{trains} | \texttt{team}\\
+  : \meta{A} ::= \texttt{The} | \texttt{the}\\
 \end{plstx}
 
 \noindent
@@ -493,7 +493,48 @@
 is recognised by the grammar. The CYK algorithm starts with the
 following triangular data structure.
 
-TBD
+\begin{figure}[t]
+\begin{center}
+  \begin{tikzpicture}[scale=0.8,line width=0.8mm]
+  \draw (-2,0) -- (4,0);
+  \draw (-2,1) -- (4,1);
+  \draw (-2,2) -- (3,2);
+  \draw (-2,3) -- (2,3);
+  \draw (-2,4) -- (1,4);
+  \draw (-2,5) -- (0,5);
+  \draw (-2,6) -- (-1,6);
+  
+  \draw (0,0) -- (0, 5);
+  \draw (1,0) -- (1, 4);
+  \draw (2,0) -- (2, 3);
+  \draw (3,0) -- (3, 2);
+  \draw (4,0) -- (4, 1);
+  \draw (-1,0) -- (-1, 6);
+  \draw (-2,0) -- (-2, 6);
+  
+  \draw (-1.5,-0.5) node {\footnotesize{}\texttt{The}}; 
+  \draw (-0.5,-1.0) node {\footnotesize{}\texttt{trainer}}; 
+  \draw ( 0.5,-0.5) node {\footnotesize{}\texttt{trains}}; 
+  \draw ( 1.5,-1.0) node {\footnotesize{}\texttt{the}}; 
+  \draw ( 2.5,-0.5) node {\footnotesize{}\texttt{student}}; 
+  \draw ( 3.5,-1.0) node {\footnotesize{}\texttt{team}};
+  
+  \draw (-1.5,0.5) node {$A$}; 
+  \draw (-0.5,0.5) node {$N$}; 
+  \draw ( 0.5,0.5) node {$N,V$}; 
+  \draw ( 1.5,0.5) node {$A$}; 
+  \draw ( 2.5,0.5) node {$N$}; 
+  \draw ( 3.5,0.5) node {$N,V$};
+
+  \draw (-2.4, 5.5) node {$1$}; 
+  \draw (-2.4, 4.5) node {$2$}; 
+  \draw (-2.4, 3.5) node {$3$}; 
+  \draw (-2.4, 2.5) node {$4$}; 
+  \draw (-2.4, 1.5) node {$5$}; 
+  \draw (-2.4, 0.5) node {$6$}; 
+  \end{tikzpicture}
+  \end{center}
+\end{figure}
 
 \end{document}