diff -r 8f85d1f61663 -r 898c25a4e399 hw08.tex --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/hw08.tex Fri Nov 23 21:21:27 2012 +0000 @@ -0,0 +1,68 @@ +\documentclass{article} +\usepackage{charter} +\usepackage{hyperref} +\usepackage{amssymb} +\usepackage{amsmath} +\usepackage{tikz} +\usetikzlibrary{automata} + +\newcommand{\dn}{\stackrel{\mbox{\scriptsize def}}{=}}% for definitions + +\begin{document} + +\section*{Homework 8} + +\begin{enumerate} +\item Suppose the following grammar for the WHILE-language: + +\begin{center} +\begin{tabular}{l} +$S \rightarrow N\cdot P$\\ +$P \rightarrow V\cdot N$\\ +$N \rightarrow N\cdot N$\\ +$N \rightarrow A \cdot N$\\ +$N \rightarrow \texttt{student} \;|\; \texttt{trainer} \;|\; \texttt{team} \;|\; \texttt{trains}$\\ +$V \rightarrow \texttt{trains} \;|\; \texttt{team}$\\ +$A \rightarrow \texttt{The} \;|\; \texttt{the}$\\ +\end{tabular} +\end{center} + + +\item Consider the following grammar + +\begin{center} +\begin{tabular}{l} +$S \rightarrow N\cdot P$\\ +$P \rightarrow V\cdot N$\\ +$N \rightarrow N\cdot N$\\ +$N \rightarrow A \cdot N$\\ +$N \rightarrow \texttt{student} \;|\; \texttt{trainer} \;|\; \texttt{team} \;|\; \texttt{trains}$\\ +$V \rightarrow \texttt{trains} \;|\; \texttt{team}$\\ +$A \rightarrow \texttt{The} \;|\; \texttt{the}$\\ +\end{tabular} +\end{center} + +where $S$ is the start symbol and $S$, $P$, $N$, $V$ and $A$ are non-terminals. +Using the CYK-algorithm, check whether or not the following string can be parsed +by the grammar: + +\begin{center} +\texttt{The trainer trains the student team} +\end{center} + +\item {\bf (Optional)} The task is to match strings where the letters are in alphabetical order---for example, +\texttt{abcfjz} would pass, but \texttt{acb} would not. Whitespace should be ignored---for example +\texttt{ab c d} should pass. The point is to try to get the regular expression as short as possible! +See: + +\begin{center} +\url{http://callumacrae.github.com/regex-tuesday/challenge11.html} +\end{center} +\end{enumerate} + +\end{document} + +%%% Local Variables: +%%% mode: latex +%%% TeX-master: t +%%% End: