This paper describes a proof search system for a non{classical logic (modal concatenation (substructural) logic) based on Gabbay's Labelled Deductive System (LDS). The logic concerned is treated as a case study. It has some unusual features which combine resource (linear, Lambek Calculus or relevance logics) with modality (intensional, temporal, or epistemic logics), and may have some useful ap...

Subset space semantics for public announcement logic in the spirit of the effort modality have been proposed by Wang and Ågotnes [17] and by Bjorndahl [6]. They propose to model the public announcement modality by shrinking the epistemic range with respect to which a postcondition of the announcement is evaluated, instead of by restricting the model to the set of worlds satisfying the announcem...

An apparently negative result of Montague has diverted research in formal modalities away from syntactic (“first-order”) approaches, encouraging rather weak and semantically complex modal formalisms, especially in representing epistemic notions. We show that, Montague notwithstanding, consistent and straightforward firstorder syntactic treatments of modality are possible, especially for belief ...

p. 1 Knowledge Without Modality: A Simplified Framework for Chronological Ignorance p. 25 Design Complete Sequential Calculus for Continuous Fixpoint Temporal Logic p. 36 Logical Omniscience and Classical Logic p. 52 Weak Implication: Theory and Applications p. 65 Deriving Inference Rules for Terminological Logics p. 84 Linear Proofs and Linear Logic p. 106 Relevance and Revision About Generali...

This paper discusses the meaning of the Bulgarian and Turkish evidentials. I argue that evidential forms in these languages have a rich semantic content: they encode the source of information, epistemic modality, and temporality. Ultimately, I show that the meaning of the Bulgarian and Turkish evidentials is not reducible to the meaning of perfect forms, from which the evidential forms are hist...

The most widely used attractive logical account of knowledge uses standard epistemic models, i.e., graphs whose edges are indistinguishability relations for agents. In this paper, we discuss more general topological models for a multi-agent epistemic language, whose main uses so far have been in reasoning about space. We show that this more geometrical perspective affords greater powers of dist...