equal
deleted
inserted
replaced
46 |
46 |
47 \item Given the regular expression $r = (a \cdot b + b)^*$. |
47 \item Given the regular expression $r = (a \cdot b + b)^*$. |
48 Compute what the derivative of $r$ is with respect to |
48 Compute what the derivative of $r$ is with respect to |
49 $a$, $b$ and $c$. Is $r$ nullable? |
49 $a$, $b$ and $c$. Is $r$ nullable? |
50 |
50 |
51 \item Prove that if $r$ is nullable then $r^{\{n\}} \equiv r^{\{..n\}}$. |
51 \item Give an argument for why the following holds: |
|
52 if $r$ is nullable then $r^{\{n\}} \equiv r^{\{..n\}}$. |
52 |
53 |
53 \item Define what is meant by the derivative of a regular |
54 \item Define what is meant by the derivative of a regular |
54 expressions with respect to a character. (Hint: The |
55 expressions with respect to a character. (Hint: The |
55 derivative is defined recursively.) |
56 derivative is defined recursively.) |
56 |
57 |