engineering recuitment GATE CSE 2023-24 Test Series Theory of Computation Context Free Languages and Pushdown Automata Context Free Grammars
For a language L over the alphabet {a, b}, let L̅ denote the complement of L and let L∗ denote the Kleene-closure of L. Consider the following sentences.
(i) L̅ and L∗ are both context-free.
(ii) L̅ is not context-free but L∗ is context-free.
(iii) L̅ is context-free but L∗ is regular.
Which of the above sentence(s) is/are true if L = {an bn | n ≥ 0} ?
1
Both (i) and (iii)
2
Only (i)
3
Only (iii)
4
Only (ii)