The transitive reflexive reduction of a partial order. An element of a partially ordered set covers another element provided that there exists no third element in the poset for which . In this case, is called an "upper cover" of and a "lower cover" of .
Cover Relation
See also
Between, Hasse Diagram, Partial OrderExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Cover Relation." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/CoverRelation.html