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Falsification-aware (hyper)sequent calculi and Kripke semantics for normal modal logics including S4 and S5 are introduced and investigated in this study. These calculi and semantics are constructed based on the idea of a falsification-aware framework for Nelson's constructive three-valued logic. The cut-elimination and completeness theorems for the proposed calculi and semantics are proved. [ABSTRACT FROM AUTHOR]

In this paper, we introduce provability multilattice logic P M L n and multilattice arithmetic M P A n which extends first-order multilattice logic with equality by multilattice versions of Peano axioms. We show that P M L n has the provability interpretation with respect to M P A n and prove the arithmetic completeness theorem for it. We formulate P M L n in the form of a nested sequent calculus and show that cut is admissible in it. We introduce the notion of a provability multilattice and develop algebraic semantics for P M L n on its basis, by the method of Lindenbaum-Tarski algebras we prove the algebraic completeness theorem. We present Kripke semantics for P M L n and establish the Kripke completeness theorem via syntactical and semantic embeddings from P M L n into G L and vice versa. Last but not least, the decidability of P M L n is shown. [ABSTRACT FROM AUTHOR]

Six interesting variants of the logics BN4 and E4--which can be considered as the 4-valued logics of the relevant conditional and (relevant) entailment, respectively--were previously developed in the literature. All these systems are related to the family of relevant logics and contain Routley and Meyer's basic logic B, which is well-known to be specifically associated with the ternary relational semantics. The aim of this paper is to develop reduced general Routley-Meyer semantics for them. Strong soundness and completeness theorems are proved for each one of the logics. [ABSTRACT FROM AUTHOR]

We offer tableaux systems for logics of essence and accident and logics of non-contingency, showing their soundness and completeness for Kripke semantics. We also show an interesting parallel between these logics based on the semantic insensitivity of the two non-normal operators by which these logics are expressed. [ABSTRACT FROM AUTHOR]

Labelled proof theory has been famously successful for modal logics by mimicking their relational semantics within deductive systems. Simpson in particular designed a framework to study a variety of intuitionistic modal logics integrating a binary relation symbol in the syntax. In this paper, we present a labelled sequent system for intuitionistic modal logics such that there is not only one but two relation symbols appearing in sequents: one for the accessibility relation associated with the Kripke semantics for normal modal logics and one for the pre-order relation associated with the Kripke semantics for intuitionistic logic. This puts our system in close correspondence with the standard birelational Kripke semantics for intuitionistic modal logics. As a consequence, it can be extended with arbitrary intuitionistic Scott–Lemmon axioms. We show soundness and completeness, together with an internal cut elimination proof, encompassing a wider array of intuitionistic modal logics than any existing labelled system. [ABSTRACT FROM AUTHOR]

This paper continues the investigation of the logic of competing theories (be they scientific, social, political etc.) initiated in [4]. We introduce a many-valued, multi-type modal language which we endow with relational semantics based on enriched reflexive graphs, inspired by Ploščica's representation of general lattices. We axiomatize the resulting many-valued, non-distributive modal logic of these structures and prove a completeness theorem. We illustrate the application of this logic through a case study in which we model competition among interacting political promises and social demands within an arena of political parties social groups. [ABSTRACT FROM AUTHOR]

In this paper we study a new operator of strong modality ..., related to the non-contingency operator Δ. We then provide soundness and completeness theorems for the minimal logic of the ...-operator. [ABSTRACT FROM AUTHOR]

Full simply typed lambda calculus is the simply typed lambda calculus extended with product types and sum types. We propose a Kripke-style semantics for full simply typed lambda calculus. We then prove soundness and completeness of type assignment in full simply typed lambda calculus with respect to the proposed semantics. The key point in the proof of completeness is the notion of a canonical model. [ABSTRACT FROM AUTHOR]

We study a version of the Stone duality between the Alexandrov spaces and the completely distributive algebraic lattices. This enables us to present lattice-theoretical models of second-order intuitionistic propositional logic which correlates with the Kripke models introduced by Sobolev. This can be regarded as a second-order extension of the well-known correspondence between Heyting algebras and Kripke models in the semantics of intuitionistic propositional logic. [ABSTRACT FROM AUTHOR]

Modal logic S5 is commonly viewed as an epistemic logic that captures the most basic properties of knowledge. Kripke proved a completeness theorem for the first-order modal logic S5 with respect to a possible worlds semantics. A multiagent version of the propositional S5 as well as a version of the propositional S5 that describes properties of distributed knowledge in multiagent systems has also been previously studied. This article proposes a version of S5-like epistemic logic of distributed knowledge with quantifiers ranging over the set of agents, and proves its soundness and completeness with respect to a Kripke semantics. [ABSTRACT FROM AUTHOR]

The best we can do is appeal to a set HT ht , the I worlds i of the context. HT ht But perhaps my reasoning was specious on metaphysical grounds - that is, from the very opening move according to which we should see context as selecting a mere set HT ht of candidates for actuality. "Julius" expresses a "cheesy mode of presentation" (Dorr et al., [9]) of one of the available acts HT ht in Figure. Free Choice is provable in this framework given that each embedded disjunct of e.g. (4a) is HT ht -accessible to the agent ( I op. cit i ., Theorem 1). [Extracted from the article]

In two recent articles, Norihiro Kamide introduces unusual variants of Nelson's paraconsistent logic and its classical extension. Kamide's systems, IP and CP , are unusual insofar as double negations in these logics behave as intuitionistic and classical negations, respectively. In this article we present Hilbert-style axiomatizations of both IP and CP. The axiom system for IP is shown to be sound and complete with respect to a four-valued Kripke semantics, and the axiom system for CP is characterized by four-valued truth tables. Moreover, we note some properties of IP and CP , and emphasize that these logics are unusual also because they are contra-classical and inconsistent but nontrivial. We point out that Kamide's approach exemplifies a general method for obtaining contra-classical logics, and we briefly speculate about a linguistic application of Kamide's logics. [ABSTRACT FROM AUTHOR]

In this paper we develope a Kripke style semantic for the logic of two-valued states on orthomodular lattices. Kripke models are built from Baer semigroups enriched with an unary operation. A completeness theorem with respect to this Kripkean semantic is established. [ABSTRACT FROM AUTHOR]

Justification logics are modal-like logics that provide a framework for reasoning about justifications. This paper introduces labeled sequent calculi for justification logics, as well as for combined modal-justification logics. Using a method due to Sara Negri, we internalize the Kripke-style semantics of justification and modal-justification logics, known as Fitting models, within the syntax of the sequent calculus to produce labeled sequent calculi. We show that all rules of these systems are invertible and the structural rules (weakening and contraction) and the cut rule are admissible. Soundness and completeness are established as well. The analyticity for some of our labeled sequent calculi are shown by proving that they enjoy the subformula, sublabel and subterm properties. We also present an analytic labeled sequent calculus for S4LPN based on Artemov–Fitting models. [ABSTRACT FROM AUTHOR]

We consider the language with temporal operators G, H and coderivative operator [d]. G means 'always in the future', H means 'always in the past' and [d] means 'around now but possibly not now'. We finitely axiomatize the logic of this language interpreted over the real line, we prove that this logic is PSPACE-complete, and that it is neither strongly complete nor Kripke-complete (and consequently that it fails the finite model property). [ABSTRACT FROM AUTHOR]