The Baire closure and its logic

The Baire algebra of a topological space X is the quotient of the algebra of all subsets of X modulo the meager sets. We show that this Boolean algebra can be endowed with a natural closure operator, resulting in a closure algebra which we denote Baire(X ). We identify the modal logic of such algebr...

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Detalles Bibliográficos
Autores: Bezhanishvili, Guram, Fernández Duque, David
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2024
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/222594
Acceso en línea:https://hdl.handle.net/2445/222594
Access Level:acceso abierto
Palabra clave:Semàntica (Filosofia)
Temps (Lògica)
Modalitat (Lògica)
Espai (Filosofia)
Semantics (Philosophy)
Tense (Logic)
Modality (Logic)
Space (Philosophy)
Descripción
Sumario:The Baire algebra of a topological space X is the quotient of the algebra of all subsets of X modulo the meager sets. We show that this Boolean algebra can be endowed with a natural closure operator, resulting in a closure algebra which we denote Baire(X ). We identify the modal logic of such algebras to be the well-known system S5, and prove soundness and strong completeness for the cases where X is crowded and either completely metrizable and continuum-sized or locally compact Hausdorff. We also show that every extension of S5 is the modal logic of a subalgebra of Baire(X ), and that soundness and strong completeness also holds in the language with the universal modality.