Use the following relation on the set {1,5,6,8}: r = {(1,1), (1,5), (1,6), (1,8), (5,1), (5,5), (6,1), (6,8), (8,1), (8,6), (8,8)}
6. draw the arrow diagram and the matrix representation for the relation r (4 points): state whether relation r is reflexive, transitive, symmetric, or antisymmetric (4 points).