Question

The pumping lemma is often used to prove that a language is:

(a) Context free

(b) Not context free

(c) Regular

(d) None of the mentioned

This question was posed to me in homework.

I want to ask this question from Pumping Lemma for Context Free Language in section Properties of Context Free Languages of Automata Theory

Answer 1

Right choice is (b) Not context free

For explanation I would say: The pumping lemma is often used to prove that a given language L is non-context-free, by showing that arbitrarily long strings s are in L that cannot be “pumped” without producing strings outside L.