Hasse diagram

{{set theory}} A diagram which represents a finite poset, in which nodes are elements of the poset and arrows represent the order relation between elements. Transitivity of the order relation is tacit, in other words, if <math> x \le y</math> and <math>y \le z </math> then no arrow is drawn from ''x'' to ''z'', but if there is no distinct ''z'' between ''x'' and ''y'' (such that <math> x \le z \le y </math>) then an arrow is draw from ''x'' to ''y''.