Q. 40 Which one of the following languages over ∑ = {a, b} is NOT context-free?
(A) {anbi ⏐ i ∈ {n, 3n, 5n}, n≥ 0}
(B) {wanwRbn ⏐ w ∈ {a, b}*, n≥ 0}
(C) {wwR ⏐ w ∈ {a, b}*}
(D) {wan bn wR ⏐ w ∈ {a, b}*, n≥ 0}
Answer: (B)
Explanation:
Q. 40 Which one of the following languages over ∑ = {a, b} is NOT context-free?
(A) {anbi ⏐ i ∈ {n, 3n, 5n}, n≥ 0}
(B) {wanwRbn ⏐ w ∈ {a, b}*, n≥ 0}
(C) {wwR ⏐ w ∈ {a, b}*}
(D) {wan bn wR ⏐ w ∈ {a, b}*, n≥ 0}
Answer: (B)
Explanation:
