, a formalization of orderings on a set that allows more general families of orderings than posets

, a poset-based approach to quantum gravity

 – Set with a preorder in which any two elements are always both less than or equal to some third element

 – Abstract structure studied in the mathematical subdisciplines of order theory and abstract algebra

, a kind of topological space that can be defined from any poset

 – continuity of a function between two partial orders.

 – strict partial order "<" in which the relation "neither a < b nor b < a" is transitive.

 – Order whose elements are all comparable

 – Mathematical proposition equivalent to the axiom of choice