1. Complete the following exercises a) For = {a, b} find regular expressions for the compliment of the following languages L = L(aa*bb) b) Let Li = L(ab*aa), L2 = L(a"bba"). Find a regular expression for (L1 n Ljl2. c) The symmetric difference of two sets S and S2 is defined as s s,-(x : x E Si or x E S2 but x is not in both S1 and S2). Show that the family of regular languages is closed under symmetric difference