The Diagram at the Right Is the Hasse Diagram for a Partially

Essay

The diagram at the right is the Hasse diagram for a partially ordered set. Referring to this diagram:
(a) List the maximal elements.
(b) List the minimal elements.
(c) Find all upper bounds for $f , g$ .
(d) Find all lower bounds for $d , f$ .
(e) Find $\operatorname { lub } ( \{ g , j , m \} )$ .
(f) Find glb $( \{ d , e \} )$ .
(g) Find the greatest element.
(h) Find the least element.
(i) Use a topological sort to order the elements of the poset represented by this Hasse diagram.