Page 1 Next

Displaying 1 – 20 of 109

Showing per page

Ideal independence, free sequences, and the ultrafilter number

Kevin Selker (2015)

Commentationes Mathematicae Universitatis Carolinae

We make use of a forcing technique for extending Boolean algebras. The same type of forcing was employed in Baumgartner J.E., Komjáth P., Boolean algebras in which every chain and antichain is countable, Fund. Math. 111 (1981), 125–133, Koszmider P., Forcing minimal extensions of Boolean algebras, Trans. Amer. Math. Soc. 351 (1999), no. 8, 3073–3117, and elsewhere. Using and modifying a lemma of Koszmider, and using CH, we obtain an atomless BA, A such that 𝔣 ( A ) = s mm ( A ) < 𝔲 ( A ) , answering questions raised by Monk...

Ideals, congruences and annihilators on nearlattices

Ivan Chajda, Miroslav Kolařík (2007)

Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica

By a nearlattice is meant a join-semilattice having the property that every principal filter is a lattice with respect to the semilattice order. We introduce the concept of (relative) annihilator of a nearlattice and characterize some properties like distributivity, modularity or 0 -distributivity of nearlattices by means of certain properties of annihilators.

Ideals in distributive posets

Cyndyma Batueva, Marina Semenova (2011)

Open Mathematics

We prove that any ideal in a distributive (relative to a certain completion) poset is an intersection of prime ideals. Besides that, we give a characterization of n-normal meet semilattices with zero, thus generalizing a known result for lattices with zero.

Ideals of noncommutative D R -monoids

Jan Kühr (2005)

Czechoslovak Mathematical Journal

In this paper, we introduce the concept of an ideal of a noncommutative dually residuated lattice ordered monoid and we show that congruence relations and certain ideals are in a one-to-one correspondence.

Idempotent semigroups and tropical algebraic sets

Zur Izhakian, Eugenii Shustin (2012)

Journal of the European Mathematical Society

The tropical semifield, i.e., the real numbers enhanced by the operations of addition and maximum, serves as a base of tropical mathematics. Addition is an abelian group operation, whereas the maximum defines an idempotent semigroup structure. We address the question of the geometry of idempotent semigroups, in particular, tropical algebraic sets carrying the structure of a commutative idempotent semigroup. We show that commutative idempotent semigroups are contractible, that systems of tropical...

Idempotent versions of Haar’s Lemma: links between comparison of discrete event systems with different state spaces and control

Mourad Ahmane, Laurent Truffet (2007)

Kybernetika

Haar's Lemma (1918) deals with the algebraic characterization of the inclusion of polyhedral sets. This Lemma has been involved many times in automatic control of linear dynamical systems via positive invariance of polyhedrons. More recently, it has been used to characterize stochastic comparison w.r.t. linear/integral ordering of Markov (reward) chains. In this paper we develop a state space oriented approach to the control of Discrete Event Systems (DES) based on the remark that most of control...

Currently displaying 1 – 20 of 109

Page 1 Next