EuDML | Browse

The number of $n$ -gaussoids is shown to be a double exponential function in $n$ . The necessary bounds are achieved by studying construction methods for gaussoids that rely on prescribing $3$ -minors and encoding the resulting combinatorial constraints in a suitable transitive graph. Various special classes of gaussoids arise from restricting the allowed $3$ -minors.

Construction of Skew Room Squares.

W.D. Wallis (1974)

Aequationes mathematicae

Dessins d'enfants: bipartite maps and Galois groups.

Jones, G. (1995)

Séminaire Lotharingien de Combinatoire [electronic only]

e-Nets and Simplex Range Queries.

D. Haussler, Emo Welzl (1987)

Discrete & computational geometry

Escher's combinatorial patterns.

Schattscheider, Doris (1997)

The Electronic Journal of Combinatorics [electronic only]

Etude sur les plans en blocs incomplets equilibres

A. Panayotopoulos (1968)

Δελτίο της Ελληνικής Μαθηματικής Εταιρίας

Generating random elements of finite distributive lattices.

Propp, James (1997)

The Electronic Journal of Combinatorics [electronic only]

Génération automatique de mots circulaires et équilibres

P. Bovet (1975)

Mathématiques et Sciences Humaines

Hyperplanes in matroids and the axiom of choice

Marianne Morillon (2022)

Commentationes Mathematicae Universitatis Carolinae

We show that in set theory without the axiom of choice ZF, the statement sH: “Every proper closed subset of a finitary matroid is the intersection of hyperplanes including it” implies AC $^{fin}$ , the axiom of choice for (nonempty) finite sets. We also provide an equivalent of the statement AC $^{fin}$ in terms of “graphic” matroids. Several open questions stay open in ZF, for example: does sH imply the axiom of choice?

Irreduzible Polynome als kombinatorische Figuren.

M. Jeger (1973)

Elemente der Mathematik

Isonemality and mononemality of woven fabrics

Bohdan Zelinka (1983)

Aplikace matematiky

The paper studies the diagrams of woven fabrics consisting of white and black squares as geometrical objects and described their symmetries. The concepts of isonemality and mononemality due to B. Grünbaum and G. C. Shephard are used. A conjecture of these authors is proved in a particular case.

Latin $(n \times n \times (n - 2))$ -parallelepipeds not completing to a Latin cube

Martin Kochol (1989)

Mathematica Slovaca

Latin parallelepipeds not completing to a cube

Martin Kochol (1991)

Mathematica Slovaca

Location of polygon vertices on circles and its application in transport studies

Ján Černý, Filip Guldan (1987)

Aplikace matematiky

The paper deals with the problem how to locate a set of polygon vertices on given circles fulfilling some criteria of "regularity" of individual and composed polygons. Specifying the conditions we can obtain a lot of particular versions of this general problem. Some of them are already solved, the others are not. Applications of this theory can be found in scheduling of periodically repeating processes, e.g. in coordination of several urban lines on a common leg, in optimization of the rhythm of...

Currently displaying 1 – 20 of 36

Page 1 Next