EQUAL is Non-Regular Using Closure Properties - | Automata Lecture 02

Learn why the EQUAL language is non-regular using closure properties and intersection with a regular language. This Theory of Automata and Formal Languages problem-solving lecture explains the proof step by step for undergraduate Computer Science students. In this FacultyLearn lecture, Instructor M. Imran Shafi explains how to prove that the EQUAL language is not regular. The key idea is to assume that EQUAL is regular, intersect it with a known regular language such as a*b*, and then show that the result becomes the classic non-regular language { a^n b^n | n ≥ 0 }. This contradiction proves that EQUAL cannot be regular. This video is part of the Theory of Automata and Formal Languages playlist and is designed for students who are learning regular languages, non-regular languages, closure properties, finite automata, and formal proof techniques.