Exercises:

1- For : = {a, b, c}

Find the RE which generates the set of all strings that start with b.

2- For : = {a, b}

Find the RE which generates the set of all strings containing any

sequence of as and bs.

3- For : = {a, b}

Find the RE which generates the set of all strings containing exactly

one b.

4- For : = {a, b, c}

Find the RE which generates the set of all strings containing exactly

one b.

5. Write a regular expression for each of the following sets of binary

strings. Use only the basic operations.

a) 0 or 11 or 101

b) only 0s

c) all binary strings

d) all binary strings except empty string

e) begins with 1, ends with 1

f) ends with 00

g) contains at least three consecutive 1s