Editing Order theory (section)

=== Universal algebra ===
As already mentioned, the methods and formalisms of [[universal algebra]] are an important tool for many order theoretic considerations. Beside formalizing orders in terms of [[algebraic structure]]s that satisfy certain identities, one can also establish other connections to algebra. An example is given by the correspondence between [[Boolean algebra (structure)|Boolean algebra]]s and [[Boolean ring]]s. Other issues are concerned with the existence of [[Free object|free constructions]], such as [[free lattice]]s based on a given set of generators. Furthermore, closure operators are important in the study of universal algebra.