Results 241 to 250 of about 79,232 (299)

Infinitary propositional normal modal logic

Studia Logica, 1987
The author introduces a propositional normal modal logic, denoted by \(KL_{\omega_ 1}\), with countable conjunction and disjunction. He gives the Hilbert type formulation of \(KL_{\omega_ 1}\), defines the class of Kripke frames characteristic for this logic (completeness theorem) and proves that \(KL_{\omega_ 1}\) has the Craig interpolation property.
S. Radev
semanticscholar   +4 more sources

Logical Consequence in Modal Logic: Alternative Semantic Systems for Normal Modal Logics

, 1973
Publisher Summary This chapter discusses the alternative semantic systems of normal modal logics. The novelty of the approach discussed in the chapter is twofold: first, to treat modal logics as consequence systems rather than logistic systems; and second, to view modal logics as extensions of non-modal ones.
G. Weaver
semanticscholar   +3 more sources

Self-extensional Paradefinite Four-valued Modal Logic Compatible with Standard Modal Logic

IEEE International Symposium on Multiple-Valued Logic, 2023
A Gentzen-style sequent calculus GMA4 is introduced for a modal extension MA4 of Avron’s self-extensional paradefinite four-valued logic. A new Gentzen-style sequent calculus GS4* for normal modal logic S4 is obtained from GMA4 by adding two special ...
N. Kamide
semanticscholar   +1 more source

Epistemic logic, skepticism, and non-normal modal logic

Philosophical Studies, 1981
P. Schotch, R. Jennings
semanticscholar   +3 more sources

Models for normal intuitionistic modal logics

Studia Logica, 1984
Kripke-style models with two accessibility relations, one intuitionistic and the other modal, are given for analogues of the modal system \({\mathbb{K}}\) based on Heyting's propositional logic. It is shown that these two relations can combine with each other in various ways.
Kosta Došen, Milan Božić
openaire   +3 more sources

Modal sequents for normal modal logics

Mathematical Logic Quarterly, 1993
AbstractWe present sequent calculi for normal modal logics where modal and propositional behaviours are separated, and we prove a cut elimination theorem for the basic system K, so as completeness theorems (in the new style) both for K itself and for its most popular enrichments. MSC: 03B45, 03F05.
openaire   +2 more sources

Non-Deterministic Many-Valued Modal Logic

IEEE International Symposium on Multiple-Valued Logic, 2022
In this paper, we extend the techniques of non-deterministic semantics for propositional logics introduced by Arnon Avron and Iddo Lev to provide an account of modal operators. We examine the counterparts of the standard concepts from deterministic modal
T. M. Ferguson
semanticscholar   +1 more source

Normal derivability in modal logic

MLQ, 2005
The main result of this paper is the following theorem: Derivations in the system of natural deduction for S4 ith general elimination rules are normalizing. The standard rule of necessitation for the modal logic S4 prevents normalization of dervations.
openaire   +2 more sources

Clausal resolution for normal modal logics

Journal of Algorithms, 2007
We present a clausal resolution-based method for normal modal logics. Differently from other approaches, where inference rules are based on the syntax of a particular set of axioms, we focus on the restrictions imposed on the binary accessibility relation for each particular normal logic.
Nalon, C., Dixon, C.
openaire   +2 more sources