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A Bruhat order for the class of $(0, 1)$ -matrices with row sum vector $R$ and column sum vector $S$ .

Brualdi, Richard A., Hwang, Suk-Geun (2005)

ELA. The Electronic Journal of Linear Algebra [electronic only]

A characterization of 1-, 2-, 3-, 4-homomorphisms of ordered sets

Radomír Halaš, Daniel Hort (2003)

Czechoslovak Mathematical Journal

We characterize totally ordered sets within the class of all ordered sets containing at least four-element chains. We use a simple relationship between their isotone transformations and the so called 1-endomorphism which is introduced in the paper. Later we describe 1-, 2-, 3-, 4-homomorphisms of ordered sets in the language of super strong mappings.

A characterization of congruence kernels in pseudocomplemented semilattices

Ivan Chajda (2002)

Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica

A characterization of finite posets of the width at most three with the fixed point property

Josef Niederle (1989)

Czechoslovak Mathematical Journal

A characterization of finite Stone pseudocomplemented ordered sets

Radomír Halaš (1996)

Mathematica Bohemica

A distributive pseudocomplemented set $S$ [2] is called Stone if for all $a \in S$ the condition $L U (a^{*}, a^{* *}) = S$ holds. It is shown that in a finite case $S$ is Stone iff the join of all distinct minimal prime ideals of $S$ is equal to $S$ .

A characterization of inductive posets

Jiří Klimeš (1985)

Archivum Mathematicum

A characterization of modular lattices

J. Dudek (1993)

Colloquium Mathematicae

A characterization of polarities whose polar lattice is orthomodular

Roman R. Zapatrin (1996)

Czechoslovak Mathematical Journal

A characterization of semilattices

G. Grätzer, J. Płonka (1970)

Colloquium Mathematicae

A characterization of tolerance-distributive tree semilattices

Ivan Chajda, Bohdan Zelinka (1987)

Czechoslovak Mathematical Journal

A characterization of well-orders

Brian Scott (1981)

Fundamenta Mathematicae

A class of $l^{1}$ -preduals which are isomorphic to quotients of $C (ω^{ω})$

Ioannis Gasparis (1999)

Studia Mathematica

For every countable ordinal α, we construct an $l_{1}$ -predual $X_{α}$ which is isometric to a subspace of $C (ω^{ω^{ω^{α} + 2}})$ and isomorphic to a quotient of $C (ω^{ω})$ . However, $X_{α}$ is not isomorphic to a subspace of $C (ω^{ω^{α}})$ .

A common approach to directoids with an antitone involution and D-quasirings

Ivan Chajda, Miroslav Kolařík (2008)

Discussiones Mathematicae - General Algebra and Applications

We introduce the so-called DN-algebra whose axiomatic system is a common axiomatization of directoids with an antitone involution and the so-called D-quasiring. It generalizes the concept of Newman algebras (introduced by H. Dobbertin) for a common axiomatization of Boolean algebras and Boolean rings.

A completion for partially ordered abelian groups.

K. Rosenthal (1984)

Semigroup forum

A computation of positive one-peak posets that are Tits-sincere

Marcin Gąsiorek, Daniel Simson (2012)

Colloquium Mathematicae

A complete list of positive Tits-sincere one-peak posets is provided by applying combinatorial algorithms and computer calculations using Maple and Python. The problem whether any square integer matrix $A \in ₙ (ℤ)$ is ℤ-congruent to its transpose $A^{t r}$ is also discussed. An affirmative answer is given for the incidence matrices $C_{I}$ and the Tits matrices $C ̂_{I}$ of positive one-peak posets I.