Hasse Diagram

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 $x < y$ in the poset, then the point corresponding to $x$ appears lower in the drawing than the point corresponding to $y$.

2. The line segment between the points corresponding to any two elements $x$ and $y$ of the poset is included in the drawing Iff $x$ covers $y$ or $y$ covers $x$.

Hasse diagrams are also called Upward Drawings.