Modular ordered sets
Modular posets and semigroups.
Modulare Inzidenzstrukturen
Monadic quasi-modal distributive nearlattices
We prove that there is a one to one correspondence between monadic finite quasi-modal operators on a distributive nearlattice and quantifiers on the distributive lattice of its finitely generated filters, extending the results given in ``Calomino I., Celani S., González L. J.: Quasi-modal operators on distributive nearlattices, Rev. Unión Mat. Argent. 61 (2020), 339--352".
Monomial nonnegativity and the Bruhat order.
Monotone and cone preserving mappings on posets
We define several sorts of mappings on a poset like monotone, strictly monotone, upper cone preserving and variants of these. Our aim is to study in which posets some of these mappings coincide. We define special mappings determined by two elements and investigate when these are strictly monotone or upper cone preserving. If the considered poset is a semilattice then its monotone mappings coincide with semilattice homomorphisms if and only if the poset is a chain. Similarly, we study posets which...
Monotonic subsequences in dimensions higher than one.
More on the complexity of cover graphs
In response to [3] and [4] we prove that the recognition of cover graphs of finite posets is an NP-hard problem.
More set-theory around the weak Freese–Nation property
We introduce a very weak version of the square principle which may hold even under failure of the generalized continuum hypothesis. Under this weak square principle, we give a new characterization (Theorem 10) of partial orderings with κ-Freese-Nation property (see below for the definition). The characterization is not a ZFC theorem: assuming Chang’s Conjecture for , we can find a counter-example to the characterization (Theorem 12). We then show that, in the model obtained by adding Cohen reals,...
Multiabbildungen und Anordnungen der Mengen
Multi-ordered posets.
Multiplicative closed maps on the set of S-subsets of an S-set.
Multiplicative functions on the lattice of non-crossing partitions and free convolution.
Multipliers on a nearlattice
MV-algebras with additive closure operators
N-anti-exchange closure operators
Natural generalization of some lattice theory concepts to partially ordered sets
ndependence of axioms for biordered sets.
Near lattices
Negaciones en retículos completos.