CS 390 Solutions to Unit 15 Exercises



p. 164

4.38 (a):

j = 0
p r(p, 1, 0) r(p, 2, 0) r(p, 3, 0)
1 b a
2 a b
3 b a

j = 1
p r(p, 1, 1) r(p, 2, 1) r(p, 3, 1)
1 b a
2 a + ab b + aa
3 b a + bb + ba

j = 2
p r(p, 1, 2) r(p, 2, 2) r(p, 3, 2)
1 + b(ab)*a b(ab)* a + b(ab)*(b + aa)
2 (ab)*a (ab)*
(ab)*(b + aa)
3 b + (a + bb)(ab)*a (a + bb)(ab)* + ba + (a + bb)(ab)*(b + aa)



Complement of DFA of Figure 4.27 (a): Simply switch accepting and non-accepting states, that is, make 3 a non-accepting state and 1 and 2 accepting states.