Let r = (10 + 0) * 11(0 + 1) * be a regular expression for the regular language L and let h(0) = ab and h(1) = ba a homomorphism. What is a regular expression for h(L)? How about h −1 (L′) if L′ is given by the regular expression r ′ = (ab + a) * bb(a + b) *?