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 - [EMAIL PROTECTED] - http://www.ime.usp.br/~rbrito/ =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=