160.212 Discrete Mathematics Assignment 2
Let N be the set of all divisors of 60, and let
P ={a∈N|4≤a≤30}.
Let ≼ be the partial order defined by a ≼ b if and only a divides b.
(a) Draw the Hasse diagram of (P, ≼).
(b) For every pair (a,b) of numbers in P evaluate the least upper bound, lub(a,b), or say it does not exist (DNE). Present the values in the form of a table.
(c) Use your answer to (b) to explain why (P, ≼) is not a lattice.