Unformatted text preview: { } { } 2  1 * *  1 * * n n n n L a b n a b a n b = ≥ ≥ I ? Explain in words and also give a string that is in one of the languages but not in the other. 2. Let { }  where there are n blocks of a's n n n n n n L a b a b a b = L . Express L as the intersection of two contextfree languages. Give contextfree grammars for each of the two languages. 3. Write a contextfree grammar for the complement of the language ( ) { }  * L ww w a b = ∈ + 4. 6.2.1 (c) 5. 6.2.3 (b)...
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 Fall '07
 HOPCROFT
 Formal language, NB, Contextfree grammar, Theory of Computing

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