Which one of the following languages over Σ = {a, b} is NOT context-free?

Let Σ be the set of all bijections from {1, ..., 5} to {1, ..., 5}. For string x = x1 x2 ... xn, let π(x) = x1 ∘ x2 ∘ ... ∘ xn. Co…

If L is a regular language over Σ = {a, b}, which one of the following languages is NOT regular?

For Σ = {a, b}, let us consider the regular language L = { x | x = a^(2 + 3k) or x = b^(10 + 12k), k >= 0 }. Which one of the foll…

Consider the following grammar where S is the start symbol, and a and b are terminal symbols. S → aSbS | bS | ε Which of the follo…

Let M be a nondeterministic finite automaton (NFA) with 6 states over a finite alphabet. Which of the following options CANNOT be …