Binary file hw07.pdf has changed

--- a/hw07.tex	Sun Nov 11 17:28:11 2012 +0000
+++ b/hw07.tex	Wed Nov 14 00:02:38 2012 +0000
@@ -57,7 +57,14 @@
 \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}

--- a/re-internal.rb	Sun Nov 11 17:28:11 2012 +0000
+++ b/re-internal.rb	Wed Nov 14 00:02:38 2012 +0000
@@ -11,11 +11,12 @@
 	#create a new regular expression based on current value of i
 	re = Regexp.new(/((a?){#{i}})(a{#{i}})/)
 
-	if re.match(string)
-		puts "matched string  a * #{i} with regex #{re}"
-	else
-		puts "unmatched string a * #{i} with regex #{re}"
-	end
+        re.match(string)
+	#if re.match(string)
+	#	puts "matched string  a * #{i} with regex #{re}"
+	#else
+	#	puts "unmatched string a * #{i} with regex #{re}"
+	#end
 	
-	puts "in = #{(Time.now - start_time) * 1000} milliseconds"
+  puts "#{i} %.5f" % (Time.now - start_time)
 end

Binary file topics.pdf has changed

--- a/topics.tex	Sun Nov 11 17:28:11 2012 +0000
+++ b/topics.tex	Wed Nov 14 00:02:38 2012 +0000
@@ -17,19 +17,20 @@
 
 \begin{itemize}
 \item What is a language?
-\item concatenation of two sets of string
+\item concatenation of two sets of strings
 \item power of a set of strings
 \end{itemize}
 
 \section{Regular Expressions}
 
 \begin{itemize}
+\item definition of regular expressions
 \item What is the language of a regular expression?
 \item When are two regular expressions are equal?
 \item {\it nullable}, {\it der}, {\it zeroable}, {\it rev}
 \item induction principle of regular expressions
 \item tokens, maximal munch rule
-\item ``negative'' regular expression 
+\item regular expression for complement language 
 \item tokenisation
 \end{itemize}