CS 162 Homework 3, 50 Points
Due: Monday, April 22, 11:55pm

Please submit your written solutions to the problems in pdf format via Gradescope.

  1. 10 points. Given two languages, L and M, define the exclusive-or of L and M as the set of all strings, w, such that w is in L and not in M or w is in M and not in L. Show that the exclusive-or of two regular languages is regular.
  2. 10 points. Excercise 1.20 parts a,b,c,d on page 86 of Sipser
  3. 10 points. Problem 1.38 on page 89 of Sipser
  4. 10 points. Problem 1.46 part c on page 90 of Sipser
  5. 10 points. Let L be the language of all strings of balanced parentheses. That is, all strings of the characters "(" and ")" such that each "(" has a matching ")". Use the Pumping Lemma to show that L is not regular.