Completeness by Modal Definitions. Application to the Epistemic Logic With Hypotheses

We investigate the variant of epistemic logic S5 for reasoning about knowledge under hypotheses. The logic is equipped with a modal operator of necessity that can be parameterized with a hypothesis representing background assumptions. The modal operator can be described as relative necessity and the...

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Bibliographic Details
Main Authors: Levan Uridia, Dirk Walther
Format: Article
Language:English
Published: Asociación Española para la Inteligencia Artificial 2020-04-01
Series:Inteligencia Artificial
Subjects:
Online Access:https://journal.iberamia.org/index.php/intartif/article/view/403
Description
Summary:We investigate the variant of epistemic logic S5 for reasoning about knowledge under hypotheses. The logic is equipped with a modal operator of necessity that can be parameterized with a hypothesis representing background assumptions. The modal operator can be described as relative necessity and the resulting logic turns out to be a variant of Chellas’ Conditional Logic. We present an axiomatization of the logic and its extension with the common knowledge operator and distributed knowledge operator. We show that the logics are decidable, complete w.r.t. Kripke as well as topological structures. The topological completeness results are obtained by utilizing the Alexandroff connection between preorders and Alexandroff spaces.
ISSN:1137-3601
1988-3064