Mary has two children, Elena and Frank. Elena is the mother of John and Jessica, and Frank is the father of Christine. a) Write down the relation R - {(a, b)| a is a parent of b} defined on the set P of the six people, so that it reflects the family structure specified above. Use the set notation, the digraph notation, and the matrix notation. b) Use the matrix notation as your starting point for computing the transitive closure of R. Apply the Boolean power method we discussed in class. Once you have derived the matrix representing the transitive closure of R, also translate it into set notation and digraph notation. c) What does the transitive closure of R specify? What name could you give it, if you considered even larger family trees including many generations