857 citations
Counting papers with at most 25 authors, so collaboration author lists do not stand in for the people here.
- Hungarian Academy of SciencesHU402 papers
- Eötvös Loránd UniversityHU156 papers
- Budapest University of Technology and EconomicsHU58 papers
- Central European UniversityAT42 papers
- École Polytechnique Fédérale de LausanneCH31 papers
- Central European University - Budapest Campus24 papers
- University of PannoniaHU23 papers
- Centre National de la Recherche ScientifiqueFR21 papers
- University College LondonGB20 papers
- University of SzegedHU20 papers
- University of Illinois Urbana-ChampaignUS18 papers
- Charles UniversityCZ15 papers
12 papers · 2 filters
Stone type representation theorems via games
Tuğba Aslan, Mohamed Khaled
The classes of relativized relation algebras (whose units are not necessarily transitive as binary relations) are known to be finitely axiomatizable. In this article, we give a new…
Varieties generated by completions
H. Andréka, I. Németi
We prove that persistently finite algebras are not created by completions of algebras, in any ordered discriminator variety. A persistently finite algebra is one without infinite s…
Nonrepresentable relation algebras from group systems
H. Andréka, S. Givant, I. Németi
A series of nonrepresentable relation algebras is constructed from groups. We use them to prove that there are continuum many subvarieties between the variety of representable rela…
The structure of random automorphisms of the rational numbers
Udayan B. Darji, Márton Elekes, Kende Kalina +2
In order to understand the structure of the "typical" element of an automorphism group, one has to study how large the conjugacy classes of the group are. For the case when typical…
A representation theorem for measurable relation algebras
S. Givant, H. Andréka
A relation algebra is called measurable when its identity is the sum of measurable atoms, and an atom is called measurable if its square is the sum of functional elements. In this…
Distances between formal theories
Michèle Friend, Mohamed Khaled, Koen Lefever +1
In the literature, there have been several methods and definitions for working out if two theories are "equivalent" (essentially the same) or not. In this article, we do something…
A representation theorem for measurable relation algebras with cyclic groups
Hajnal Andréka, Steven Givant
A relation algebra is measurable if the identity element is a sum of atoms, and the square x;1;x of each subidentity atom x is a sum of non-zero functional elements. These function…
The variety of coset relation algebras
Steven Givant, Hajnal Andréka
A coset relation algebra is one embeddable into some full coset relation algebra, the latter is an algebra constructed from a system of groups, a coordinated system of isomorphisms…
Coset relation algebras
H. Andréka, S. Givant
A measurable relation algebra is a relation algebra in which the identity element is a sum of atoms that can be measured in the sense that the "size" of each such atom can be defin…
Relation algebras and groups
Steven Givant
Generalizing results of Jónsson and Tarski, Maddux introduced the notion of a pair-dense relation algebra and proved that every pair-dense relation algebra is representable. The no…
Term algebras of elementarily equivalent atom structures
H. Andréka, I. Németi
We exhibit two relation algebra atom structures such that they are elementarily equivalent but their term algebras are not. This answers Problem 14.19 in the book Hirsch, R. and Ho…
On Generalization of Definitional Equivalence to Languages with Non-Disjoint Signatures
Koen Lefever, Gergely Székely
For simplicity, most of the literature introduces the concept of definitional equivalence only to languages with disjoint signatures. In a recent paper, Barrett and Halvorson intro…