slides04.tex
changeset 39 e5fb17c02508
parent 38 cad34315db1b
child 40 e7472b79be9d
equal deleted inserted replaced
38:cad34315db1b 39:e5fb17c02508
   281 \includegraphics[scale=0.7]{pics/ch3.jpg}
   281 \includegraphics[scale=0.7]{pics/ch3.jpg}
   282 \end{center}\pause
   282 \end{center}\pause
   283 
   283 
   284 \begin{itemize}
   284 \begin{itemize}
   285 \item start can be an accepting state
   285 \item start can be an accepting state
   286 \item there is no accepting state
   286 \item it is possible that there is no accepting state
   287 \item all states are accepting
   287 \item all states might be accepting (but does not necessarily mean all strings are accepted)
   288 \end{itemize}
   288 \end{itemize}
   289 
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   505 
       
   506 
       
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   508 \mode<presentation>{
       
   509 \begin{frame}[c]
       
   510 
       
   511 \begin{enumerate}
       
   512 \item Take all pairs \bl{(q, p)} with \bl{q $\not=$ p}
       
   513 \item Mark all pairs that accepting and non-accepting states
       
   514 \item For  all unmarked pairs \bl{(q, p)} and all characters \bl{c} tests wether
       
   515 \begin{center}
       
   516 \bl{($\delta$(q,c), $\delta$(p,c))}
       
   517 \end{center} 
       
   518 are marked. If yes, then also mark bl{(q, p)} 
       
   519 \item Repeat last step until no chance.
       
   520 \item All unmarked pairs can be merged.
       
   521 \end{enumerate}
       
   522 
       
   523 \end{frame}}
       
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   525 
       
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   529 \mode<presentation>{
   508 \begin{frame}[c]
   530 \begin{frame}[c]
   509 
   531 
   510 Given the function 
   532 Given the function 
   567 \end{itemize}
   589 \end{itemize}
   568 
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   569 \end{frame}}
   591 \end{frame}}
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   573 \mode<presentation>{
       
   574 \begin{frame}[c]
       
   575 
       
   576 Assume you have an alphabet consisting of the letters \bl{$a$}, \bl{$b$} and \bl{$c$} only.
       
   577 (a) Find a regular expression that recognises the two strings \bl{$ab$} and \bl{$ac$}. (b)
       
   578 Find a regular expression that matches all strings \emph{except} these two strings.
       
   579 Note, you can only use regular expressions of the form 
       
   580 \begin{center}
       
   581 \bl{$r ::= \varnothing \;|\; \epsilon \;|\; c  \;|\; r_1 + r_2  \;|\; r_1 \cdot r_2 \;|\; r^*$}
       
   582 \end{center}
       
   583 
       
   584 \end{frame}}
       
   585 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
       
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   588 \end{document}
   597 \end{document}
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