19 \end{center} | 
    19 \end{center} | 
    20   | 
    20   | 
    21       If you want to follow the code I present during the  | 
    21       If you want to follow the code I present during the  | 
    22       lectures, read the handout about Scala.  | 
    22       lectures, read the handout about Scala.  | 
    23   | 
    23   | 
    24 \item {\bf (Optional)} Have a look at the crawler programs. | 
    24 %\item {\bf (Optional)} Have a look at the crawler programs. | 
    25       Can you find a usage for them in your daily programming  | 
    25 %      Can you find a usage for them in your daily programming  | 
    26       life? Can you improve them? For example in cases there  | 
    26 %      life? Can you improve them? For example in cases there  | 
    27       are links that appear on different recursion levels, the  | 
    27 %      are links that appear on different recursion levels, the  | 
    28       crawlers visit such web-pages several times. Can this be  | 
    28 %      crawlers visit such web-pages several times. Can this be  | 
    29       avoided? Also, the crawlers flag as problematic any page  | 
    29 %      avoided? Also, the crawlers flag as problematic any page  | 
    30       that gives an error, but probably only 404 Not Found  | 
    30 %      that gives an error, but probably only 404 Not Found  | 
    31       errors should be flagged. Can you change that?)  | 
    31 %      errors should be flagged. Can you change that?)  | 
    32   | 
    32   | 
    33 \item Read the handout of the first lecture and the handout  | 
    33 \item Read the handout of the first lecture and the handout  | 
    34       about notation. Make sure you understand the concepts of  | 
    34       about notation. Make sure you understand the concepts of  | 
    35       strings and languages. In the context of the CFL-course,  | 
    35       strings and languages. In the context of the CFL-course,  | 
    36       what is meant by the term \emph{language}? | 
    36       what is meant by the term \emph{language}? |