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Related papers: Notes on the Union Closed Sets Conjecture

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It is conjectured that if a finite set of points in the plane contains many collinear triples then there is some structure in the set. We are going to show that under some combinatorial conditions such pointsets contain special…

Combinatorics · Mathematics 2023-07-25 Jozsef Solymosi

We introduce an algorithm that conjectures the structure of a permutation class in the form of a disjoint cover of "rules"; similar to generalized grid classes. The cover is usually easily verified by a human and translated into an…

Combinatorics · Mathematics 2017-05-12 Christian Bean , Bjarki Gudmundsson , Henning Ulfarsson

In this paper we disprove the following conjectured generalization of the Contraction Mapping Theorem (due to J.D. Stein Jr.): Let X be a complete metric space and let F be a finite family of self-maps of X. Suppose there is a postive…

Metric Geometry · Mathematics 2007-05-23 Tim D. Austin

In this paper, we argue that while the concept of a set-theoretic paradox (or paradoxical set) can be relatively well-defined within a formal setting, the concept of a set-theoretic hypodox (or hypodoxical set) remains significantly less…

Logic · Mathematics 2025-01-31 Timotej Šujan

In this article we will describe an algorithm to constructively enumerate non-isomorphic Union closed Sets and Moore sets. We confirm the number of isomorphism classes of Union closed Sets and Moore sets on n<=6 elements presented by other…

Combinatorics · Mathematics 2017-01-16 Gunnar Brinkmann , Robin Deklerck

The unrestricted T-system is a family of relations in the Grothendieck ring of the category of the finite-dimensional modules of the Yangian or the quantum affine algebra associated with a complex simple Lie algebra. The unrestricted…

Quantum Algebra · Mathematics 2010-05-26 Rei Inoue , Osamu Iyama , Atsuo Kuniba , Tomoki Nakanishi , Junji Suzuki

Mubayi's Conjecture states that if $\mathcal{F}$ is a family of $k$-sized subsets of $[n] = \{1,\ldots,n\}$ which, for $k \geq d \geq 2$, satisfies $A_1 \cap\cdots\cap A_d \neq \emptyset$ whenever $|A_1 \cup\cdots\cup A_d| \leq 2k$ for all…

Combinatorics · Mathematics 2018-11-01 Adam Mammoliti , Thomas Britz

The kernel of analysis, to me anyway, is the following idea: A point is arbitrarily close to a set if every neighborhood of the point intersects the set. Defining ``arbitrarily close'' in this way provides a foundation for classical results…

History and Overview · Mathematics 2022-08-22 John A. Rock

It is shown that (1) if a good set has finitely many related components, then they are full, (2) loops correspond one-to-one to extreme points of a convex set. Some other properties of good sets are discussed.

General Mathematics · Mathematics 2007-05-23 K Gowri Navada

The notion of rough set captures indiscernibility of elements in a set. But, in many real life situations, an information system establishes the relation between different universes. This gave the extension of rough set on single universal…

Artificial Intelligence · Computer Science 2013-01-30 B. K. Tripathy , D. P. Acharjya

A new characterization is given to describe implication bases of a closure system in terms of the system's quasi-closed sets. Using this characterization, it is possible to show that groups of implications corresponding to distinct…

Logic · Mathematics 2023-05-30 Todd Bichoupan

A family of $k$-subsets $A_1, A_2, ..., A_d$ on $[n]=\{1,2,..., n\}$ is called a $(d, c)$-cluster if the union $A_1\cup A_2 \cup ... \cup A_d$ contains at most $ck$ elements with $c<d$. Let $\mathcal{F}$ be a family of $k$-subsets of an…

Combinatorics · Mathematics 2009-04-24 William Y. C. Chen , Jiuqiang Liu , Larry X. W. Wang

Current techniques for generating a knowledge space, such as QUERY, guarantees that the resulting structure is closed under union, but not that it satisfies wellgradedness, which is one of the defining conditions for a learning space. We…

Combinatorics · Mathematics 2009-08-28 David Eppstein , Jean-Claude Falmagne , Hasan Uzun

We demonstrate the truth of the sunflower conjecture by showing that a family $\mathcal{F}$ of sets each of cardinality at most $m$ includes a $k$-sunflower, if $|\mathcal{F}| > ( c k )^{2m}$ for a constant $c>0$ independent of $m$ and $k$,…

Combinatorics · Mathematics 2026-04-29 Junichiro Fukuyama

The sets used to construct other mathematical objects are pure sets, which means that all of their elements are sets, which are themselves pure. One set may therefore be within another, not as an element, but as an element of an element, or…

Logic · Mathematics 2019-05-16 Ruadhan O'Flanagan

Using a new technique, we prove a rich family of special cases of the matroid intersection conjecture. Roughly, we prove the conjecture for pairs of tame matroids which have a common decomposition by 2-separations into finite parts.

Combinatorics · Mathematics 2014-04-25 Nathan Bowler , Johannes Carmesin

We call a family of sets intersecting, if any two sets in the family intersect. In this paper we investigate intersecting families $\mathcal{F}$ of $k$-element subsets of $[n]:=\{1,\ldots, n\},$ such that every element of $[n]$ lies in the…

Combinatorics · Mathematics 2019-07-02 Ferdinand Ihringer , Andrey Kupavskii

We show that any open set in $\R^n$ is a union of an ascending sequence of bounded open sets with analytic boundary. This is just a technical result, which is probably known. We believe, however, that it can be useful for studing BVPs on…

General Topology · Mathematics 2010-12-09 Dmitry Vorotnikov

In this paper we investigate three unsolved conjectures in geometric combinatorics, namely Falconer's distance set conjecture, the dimension of Furstenburg sets, and Erdos's ring conjecture. We formulate natural $\delta$-discretized…

Classical Analysis and ODEs · Mathematics 2007-05-23 Nets Hawk Katz , Terence Tao

Families of unconditionally $\tau$-closed and $\tau$-algebraic sets in a group are defined, which are natural generalizations of unconditionally closed and algebraic sets defined by Markov. A sufficient condition for the coincidence of…

Group Theory · Mathematics 2007-06-14 Ol'ga V. Sipacheva
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