9 papers
Two questions of Kowalski-SÅomczyÅska
Zalán Gyenis
That the inclusion is proper and Mod is not generated by free -algebras is proved, answering two open questions from Kowals…
Uncountably many conditionally inaccessible decisions exist in every finite probability space
Zalán Gyenis, Miklós Rédei, Leszek WroÅski
In a recent paper \cite{Redei-Jing2026} the notion of conditional -inaccessibility of a decision based on utility maximization was defined and examples of conditionally -inac…
More on modal logics and deduction
Zalán Gyenis, Zalán Molnár, Ãvge Ãztürk
We study the relation between additivity and deduction theorems in the algebraic semantics of congruential modal logic. Additivity of the modal operator is well-known to imply the…
On covers of quasivarieties of p-algebras
Zalán Gyenis, Zalán Gyenis
This paper characterizes the covers of varieties of p-algebras in the lattice of quasivarieties of p-algebras. In particular, it is shown that every such variety has exactly one co…
Permutations, substitutions and finite axiomatizability
Hajnal Andréka, Zalán Gyenis, István Németi
Algebras of relations form an algebraic framework for the study of logical systems, extending the correspondence between Boolean algebras and propositional logic. Tarski's represen…
Probabilities are always axiomatizable
Zalán Gyenis
In this paper we study the interaction between logic and probability. In particular, we show that the convex hull of evaluations of a broad class of logics is always effectively ax…