Reflexive insensitive modal logics

We analyze a class of modal logics rendered insensitive to reflexivity by way of a modification to the semantic definition of the modal operator. We explore the extent to which these logics can be characterized, and prove a general completeness theorem on the basis of a translation between normal modal logics and their reflexive-insensitive counterparts. Lastly, we provide a sufficient semantic condition describing when a similarly general soundness result is also available

Reflexive-insensitive Modal Logics

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)We analyze a class of modal logics rendered insensitive to reflexivity by way of a modification to the semantic definition of the modal operator. We explore the extent to which these logics can be characterized, and prove a general completeness theorem on the basis of a translation between normal modal logics and their reflexive-insensitive counterparts. Lastly, we provide a sufficient semantic condition describing when a similarly general soundness result is also available.9167180CAPES (Coordination for the Improvement of Higher Education Personnel) in BrazilFAPESP (Sao Paulo Research Foundation) [2013/25095-4]Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

A Non-standard kripke semantics for the minimal deontic logic

In this paper we study a new operator of strong modality ⊞, related to the non-contingency operator ∆. We then provide soundness and completeness theorems for the minimal logic of the ⊞-operatorCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP001403272/2019-02016/25891-

Neighborhood Semantics for Logics of Unknown Truths and False Beliefs

This article outlines a semantic approach to the logics of unknown truths, and the logic of false beliefs, using neighborhood structures, giving results on soundness, completeness, and expressivity. Relational semantics for the logics of unknown truths are also addressed, specically the conditions under which sound axiomatizations of these logics might be obtained from their normal counterparts, and the relationship between refexive insensitive logics (RI-logics) and logics containing the provability operator as the primary modal operator

Neighborhood Semantics for Logics of Unknown Truths and False Beliefs

This article outlines a semantic approach to the logics of unknown truths, and the logic of false beliefs, using neighborhood structures, giving results on soundness, completeness, and expressivity. Relational semantics for the logics of unknown truths are also addressed, specically the conditions under which sound axiomatizations of these logics might be obtained from their normal counterparts, and the relationship between refexive insensitive logics (RI-logics) and logics containing the provability operator as the primary modal operator

Reflexive-insensitive logics, the box-dot translation, and the modal logic of generic absoluteness

In this paper we analyze the connection between reflexive-insensitive modal logics, logics of provability, and the modal logic of forcing. Because of the inter-definability of the ∘-operator that characterizes the reflexive-insensitive logics and Boolos’s ⊡-operator, characterization results for the reflexive-insensitive logics can be used to give a partial solution of the boxdot conjecture, and to illuminate some closely related problems. In turn, this will facilitate the application of reflexive-insensitive logics to the study of the modal logic of forcing and truth and the logic of forcing persistent sentences. We then show that the modal logic of forcing, the modal logic of forcing and truth, and the modal logic of forcing persistency give rise to the same characterizability results. We conclude by arguing that the modal logic of forcing should be better understood as the modal logic of generic absoluteness