Consider the following relation r on the power set p(z) of the integers: r= {(a, b) e p(z) ~ p(z) | vaea 3beb alb} determine whether or not r is (a) reflexive, (b) symmetric, (c) transitive. you will need to prove or disprove the given property in each case. if you give a counter- example, you must explain why it is a counter-example.