Covering graphs and subdirect decompositions of partially ordered sets
It is well known that the linear extension majority (LEM) relation of a poset of size can contain cycles. In this paper we are interested in obtaining minimum cutting levels such that the crisp relation obtained from the mutual rank probability relation by setting to its elements smaller than or equal to , and to its other elements, is free from cycles of length . In a first part, theoretical upper bounds for are derived using known transitivity properties of the mutual rank probability...
A representation of cyclically ordered sets by means of partial semigroups with an additional unary operation is constructed.
Some modifications of the definition of density of subsets in ordered (= partially ordered) sets are given and the corresponding concepts are compared.