4a)

4. (a) Consider the following relation R on the set {p,q,r,s} : R={(p,q),(q,r),(r,q),(r,s),(s,s)}. Represent R by its matrix (with the elements of {p,q,r,s} listed in the indicated order) (2 marks) Use Warshall's algorithm to compute the transitive closure R of R. Show your working and the resulting relation R. (6 marks)