How do you classify languages into regular, context free, and phrase-structure?

Posted by confused on Stack Overflow See other posts from Stack Overflow or by confused
Published on 2010-05-11T01:03:58Z Indexed on 2010/05/11 1:14 UTC
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language-theory

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regular-language

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context-free-grammar

If you're given a language, how do you figure out if it's regular, CF but not regular, or phrase-structure but not CF? Is there a good way to attack this problem? I could randomly try to make FAs or PDAs, but I feel like there's a better way to do it.

Classic example:

L = { a^n b^n c^n | n >= 0 }

Where would one start? Thanks.

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