I read that pumping lemma is sufficient condition to prove non regularity of languages but not necessary condition.

I know the first part that it is sufficient is true but not able to understand why is it not necessary. Can someone please help me with this statement?

  • $\begingroup$ If the condition is not necessary then there must be some other way to prove language is non regular right ? Can you tell me what is that way ? $\endgroup$
    – Sagar P
    Nov 12, 2017 at 5:27
  • $\begingroup$ We have a reference question for that: cs.stackexchange.com/questions/1031/…. $\endgroup$ Nov 12, 2017 at 8:20
  • $\begingroup$ Thanks Yuval . I got my answer from that reference question. I marked it as duplicate. $\endgroup$
    – Sagar P
    Nov 12, 2017 at 9:41


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