CST229 Week 4

1. CST229 Week 4 • Questions or concerns? • Test#1 next Thursday • Homework #3 due • Hand back Homework #2 • Reading: Chapters 5 & 7 • In-Class Exercise #4a • Chapter 5 – Machine to recognize languages • In-Class Exercise#4b • Test#1

2. In-Class Exercise #4a Construct regular expressions for these languages over = {a, b}: • L = {anbm| n+m is even} • L = {w | |w| mod 3 = 0} • L = { w | number of b’s in w is divisible by 5}

3. Regular Expressions • Construct regular expressions for these: • L1 = {a1b1} • L2 = {a2b2} • L3 = {a3b3} • L6 = {a6b6} • Ln = {an | n ≥ 0} • Lnm= {anbm| n, m ≥ 0} • Ldoublen= {anbn | n ≥ 0}

4. CST229 Week 4 • Questions or concern? • Test#1 next Thursday • Homework #3 due • Hand back Homework #2 • Reading: Chapters 5 & 7 • In-Class Exercise #4a • Chapter 5 – Machine to recognize languages • In-Class Exercise#4b • What’s going to be on the test

5. In-Class Exercise #4b Construct Finite Automata for these languages • L = {anbm| n+m is even} • L = {w | |w| mod 3 = 0} • L = { w | number of b’s in w is divisible by 5} • L = { w | w contains even number of a’s and even number of b’s}

6. Finite Automata • Construct FAs for these: • L1 = {a1b1} • L2 = {a2b2} • L3 = {a3b3} • L6 = {a6b6} • Ln = {an | n ≥ 0} • Lnm= {anbm| n, m ≥ 0} • Ldoublen= {anbn | n ≥ 0}

7. Next Thursday 2/6 • First hour • Talk about Lab#1 • Last minute questions about the test • Second hour ++ • Test#1 • Covers Homeworks #1 - #3 • Set theory • Permutations / Combinations • Chapter 2 problems • Chapter 3 problems • Chapter 4 problems • Open notes / Open book