diff -r bea2dd1c7e73 -r ffde837b1db1 hws/hw01.tex --- a/hws/hw01.tex Thu Sep 26 10:52:54 2013 +0100 +++ b/hws/hw01.tex Thu Sep 26 11:05:54 2013 +0100 @@ -18,6 +18,9 @@ \item {\bf (Optional)} Have a look at the crawler programs. Can you find a usage for them in your daily programming life? +\item Read the handout of the first lecture and make sure you +understand the concepts of strings and languages. + \item In the context of the AFL-course, what is meant by the term \emph{language}? \item Give the definition for regular expressions. What is the meaning of a @@ -29,8 +32,6 @@ \item How is the power of a language defined? (Hint: There are two rules, one for $\_\!\_^0$ and one for $\_\!\_^{n+1}$.) -\item Given the regular expressions $r_1 = \epsilon$ and $r_2 = \varnothing$ and $r_3 = a$. -How many strings can the regular expressions $r_1^*$, $r_2^*$ and $r_3^*$ each match? \end{enumerate}