finding a string whether belongs to CFL or not

wheatstone <mightydreams@gmail.com>
Tue, 22 Jun 2010 12:28:05 -0700 (PDT)

          From comp.compilers
Related articles
finding a string whether belongs to CFL or not mightydreams@gmail.com (wheatstone) (2010-06-22)
Re: finding a string whether belongs to CFL or not ott@mirix.org (Matthias-Christian Ott) (2010-06-23)
Re: finding a string whether belongs to CFL or not gene.ressler@gmail.com (Gene) (2010-06-25)
Re: finding a string whether belongs to CFL or not ott@mirix.org (Matthias-Christian Ott) (2010-06-25)
Re: finding a string whether belongs to CFL or not cfc@shell01.TheWorld.com (Chris F Clark) (2010-06-27)
Re: finding a string whether belongs to CFL or not gene.ressler@gmail.com (Gene) (2010-06-28)
| List of all articles for this month |
From: wheatstone <mightydreams@gmail.com>
Newsgroups: comp.compilers
Date: Tue, 22 Jun 2010 12:28:05 -0700 (PDT)
Organization: Compilers Central
Keywords: parse, theory, question
Posted-Date: 23 Jun 2010 09:57:29 EDT

If I am given a string
a^nb^na^n


where a^n is a to the power n is this language an example of
a) context free,
b)non context free,
c) not context free but whose complement is CF,
d) context free but whose complement is not context free.


The answer in book is given to be b and c and I am not able to
understand what is complement of CF language.
Any help would be appreciated.
Thanks.


Post a followup to this message

Return to the comp.compilers page.
Search the comp.compilers archives again.