A Hasse diagram is a graphical representation of a partially ordered set (poset). The set consisting of the divisors of a positive integer can be considered a poset under the relation if divides . For this poset, any edge in the diagram is such that the number below divides the number immediately above. If is a product of prime numbers, then is isomorphic to the set of subsets of with the relation if is contained in ; hence, is a Boolean algebra in this case.