Mark the strings below which match the regular expression ab

Mark the strings below which match the regular expression (a|b)*(a|c)b* over the alphabet ={a,b, c}

(empty string)

aabb

aca

bbb

abcb

This is a discrete mathematics problem.

Solution

Here in the given regular expression we have (a/b)*(a/c)b*

It denotes the set of strings starting with a, zero or more b\'s and finally optional c.

so from the given data which satisfies the above condition are

aabb

aca

abcd