Re: OT: regular expression question
On Dec 08 2000, Hubert Chan wrote:
> Oops. There should be a "| \epsilon" at the end of that (where
> \epsilon is the empty string) if you count the empty string as a
> palindrome. If not, then you should add "| aa | bb".
No, it's not the same thing. The former language generated by
the grammar with the production S -> \varepsilon has the empty
string, while, if you substitute it by S -> aa | bb, then your
new language does not contain \varepsilon.
[]s, Roger...
--
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Rogerio Brito - rbrito@iname.com - http://www.ime.usp.br/~rbrito/
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Reply to: