In this paper, the modal logic over classes of structures definable by universal first-order
Horn formulas is studied. We show that the satisfiability problems for that logics are …

We study elementary modal logics, ie modal logic considered over first-order definable
classes of frames. The classical semantics of modal logic allows infinite structures, but often …

We show that modal logic over universally first-order definable classes of transitive frames is
decidable. More precisely, let K be an arbitrary class of transitive Kripke frames definable by …

We consider the satisfiability problem for modal logic over first-order definable classes of
frames. We confirm the conjecture from Hemaspaandra and Schnoor [2008] that modal logic …

Modal logic for almost a hundred year has been an important topic in many academic
disciplines, including philosophy, mathematics, linguistics and computer science. Currently it …

Modal logic plays an important role in various areas of computer science, including
verification and knowledge representation. In many practical applications it is natural to …

We study multimodal logics over universally first-order definable classes of frames. We show
that even for bimodal logics, there are universal Horn formulas that define set of frames such …

We study variants of the satisfiability problem of elementary modal logics, ie, modal logic
considered over first-order definable classes of frames. The standard semantics of modal …

Modal logic was first introduced by philosophers to study the deductive behaviour of the
expressions it is necessary that and it is possible that. Nowadays, it is widely used in several …