Consider the set A = {a, ab, aab), a set of strings over the alphabet (a, b). For strings, we have an interesting notation to define the universal set U in this context. We take U defined by the Kleene closure (*) of the alphabet: i20 Answer the following questions about this statement 3(a) What is the shortest string in the universe for A? 3(b) write the contents of ta, bPUfa, b)' u {a,b) 2 in roster notation. 3(c) Write the contents of A A in roster notation. Note that when paring up the strings, you are concatenating the strings. Your final answer should not contain any pairs, only strings, and should remove all duplicates from the set