For each of the following languages show that the number of equivalence classes of the right congruence relation over A is infinite (so the language cannot be regular): (a) L = {x EA* | num(a,x)num(b,x)); (b) the set of all such strings that if the string begins with an a, then each sequence of consecutive symbols a is followed by the same number of consecutive symbols b; if the string begins with a b, then each sequence of consecutive symbols b is followed by the same number of consecutive symbols a