# Theory Of Computation MCQ - Context free languages

36:

Let L be a language recognizable by a finite automaton. The language

REVERSE (L) = {w such that w is the reverse of v where v ∈ L } is a

 A. regular language B. context-free language C. context-sensitive language D. recursively enumerable language Answer Report Discuss Option: A Explanation : Click on Discuss to view users comments. Write your comments here:
37:

The grammars G = ( { s }, { 0, 1 }, p , s)
where p = (s —> 0S1, S —> OS, S —> S1, S —>0} is a

 A. recursively enumerable language B. regular language C. context-sensitive language D. context-free language Answer Report Discuss Option: B Explanation : Click on Discuss to view users comments. Write your comments here:
38:

The logic of pumping lemma is a good example of

 A. pigeon-hole principle B. divide-and-conquer technique C. recursion D. iteration Answer Report Discuss Option: A Explanation : The  pigeon hole principle is nothing more than the obvious remark: if you have fewer pigeon holes than pigeons and you put every pigeon in a pigeon hole, then there must result at least one pigeon hole with more than one pigeon. It is surprising how useful this can be as a proof strategy. In the theory of formal languages in computability theory, a pumping lemma or pumping argument states that, for a particular language to be a member of a language class, any sufficiently long string in the language contains a section, or sections, that can be removed, or repeated any number of times, with the resulting string remaining in that language. The proofs of these lemmas typically require counting arguments such as the pigeonhole principle. So the answer is 'A' Click on Discuss to view users comments. Write your comments here:
39:

The intersection of CFL and regular language