Identify Non Regular Language using Pumping Lemma
Wikipedia, "Pumping Lemma for Regular Languages," https://en.wikipedia.org/wiki/Pumping_lemma_for_regular_languages
TutorialKart, "Pumping Lemma for Regular Languages," https://www.tutorialkart.com/automata/pumping-lemma-for-regular-languages/
- Aaron Steven White, "Pumping Lemma Explanation," https://aaronstevenwhite.io/intro-to-cl/phonological-patterns/generative-capacity/pumping-lemma.html