equal
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68 |
68 |
69 there are several values for how these regular expressions can |
69 there are several values for how these regular expressions can |
70 recognise the strings (for 1) $ab$ and (for 2) $aaa$. Give in each case |
70 recognise the strings (for 1) $ab$ and (for 2) $aaa$. Give in each case |
71 \emph{all} the values and indicate which one is the POSIX value. |
71 \emph{all} the values and indicate which one is the POSIX value. |
72 |
72 |
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73 \item Given the regular expression $(a + b)^* \cdot b \cdot (a + b)^*$, |
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74 which of the following regular expressions are equyivalent |
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75 |
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76 \begin{center} |
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77 \begin{tabular}{ll} |
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78 1) & $(ab + bb)^* \cdot (a + b)^*$\\ % no |
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79 2) & $(a + b)^* \cdot (ba + bb + b) \cdot (a + b)^*$\\ % yes |
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80 3) & $(a + b)^* \cdot (a + b) \cdot (a + b)^*$ % no |
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81 \end{tabular} |
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82 \end{center} |
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83 |
73 \item Parsing combinators consist of atomic parsers, alternative |
84 \item Parsing combinators consist of atomic parsers, alternative |
74 parsers, sequence parsers and semantic actions. What is the purpose |
85 parsers, sequence parsers and semantic actions. What is the purpose |
75 of (1) atomic parsers and of (2) semantic actions? |
86 of (1) atomic parsers and of (2) semantic actions? |
76 |
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77 |
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78 |
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79 |
87 |
80 \item \POSTSCRIPT |
88 \item \POSTSCRIPT |
81 \end{enumerate} |
89 \end{enumerate} |
82 |
90 |
83 \end{document} |
91 \end{document} |