A Hasse diagram is a graphical rendering of a partially ordered set displayed via the cover relation of the partially ordered set with an implied upward orientation. A point is drawn for each element of the poset, and line segments are drawn between these points according to the following two rules:
1. If in the poset, then the point corresponding to appears lower in the drawing than the point corresponding to .
2. The line segment between the points corresponding to any two elements and of the poset is included in the drawing iff covers or covers .
Hasse diagrams are also called upward drawings.
Hasse diagrams for a graph are implemented as HasseDiagram[g] in the Wolfram Language package Combinatorica` , where is a directed acyclic Combinatorica graph object. They may be implemented in a future version of the Wolfram Language as HasseGraph.
The above figures show the Hasse diagrams for Boolean algebras of orders , 3, 4, and 5. In particular, these figures illustrate the partition between left and right halves of the lattice, each of which is the Boolean algebra on elements (Skiena 1990, pp. 169-170). These correspond precisely to the hypercube graphs .