Theory of Computation Lecture 26: Closure Properties of Context-Free Languages (1)

Theory of Computation Lecture 26: Closure Properties of Context-Free Languages (1):
Closure under Union, Concatenation and Star

References:

“Introduction to the Theory of Computation”, Michael Sipser, Third Edition, Cengage Learning

“An Introduction to Formal Languages and Automata”, Peter Linz, Jones and Bartlett Publishers