A Defeasible Logic of Policy-based Intention

Most of the theories on formalising intention interpret it as a unary modal operator in Kripkean semantics, which gives it a monotonic look. We argue that policy-based intentions exhibit non-monotonic behaviour which could be captured through a non-monotonic system like defeasible logic. The proposed technique alleviates most of the problems related to logical omniscience

Disjunctive bases: normal forms and model theory for modal logics

We present the concept of a disjunctive basis as a generic framework for normal forms in modal logic based on coalgebra. Disjunctive bases were defined in previous work on completeness for modal fixpoint logics, where they played a central role in the proof of a generic completeness theorem for coalgebraic mu-calculi. Believing the concept has a much wider significance, here we investigate it more thoroughly in its own right. We show that the presence of a disjunctive basis at the "one-step" level entails a number of good properties for a coalgebraic mu-calculus, in particular, a simulation theorem showing that every alternating automaton can be transformed into an equivalent nondeterministic one. Based on this, we prove a Lyndon theorem for the full fixpoint logic, its fixpoint-free fragment and its one-step fragment, a Uniform Interpolation result, for both the full mu-calculus and its fixpoint-free fragment, and a Janin-Walukiewicz-style characterization theorem for the mu-calculus under slightly stronger assumptions. We also raise the questions, when a disjunctive basis exists, and how disjunctive bases are related to Moss' coalgebraic "nabla" modalities. Nabla formulas provide disjunctive bases for many coalgebraic modal logics, but there are cases where disjunctive bases give useful normal forms even when nabla formulas fail to do so, our prime example being graded modal logic. We also show that disjunctive bases are preserved by forming sums, products and compositions of coalgebraic modal logics, providing tools for modular construction of modal logics admitting disjunctive bases. Finally, we consider the problem of giving a category-theoretic formulation of disjunctive bases, and provide a partial solution

Montague Grammar, Categories and Types: a presentation of actual theories in Semantics and Discourse Interpretation

This paper is a presentation of the origins of Montague Grammar in relation to Generative Grammar and Categorical Grammars and its actual application to linguistic models of discourse interpretation. The proposed model is based in Gabbay’s Labeled Deductive Systems, as it was developed by Dov Gabbay and Ruth Kempson in the 90’s

The artifactualization of reference and "substances" on the Web. : Why (HTTP) URIs do not (always) refer nor resources hold by themselves (post-print)

ISSN 2155-9708, http://www.apaonline.org/APAOnline/Publication_Info/Newsletters/APAOnline/PublicatioInternational audienceIn this paper we show that URIs, sometimes dubbed "philosophical proper names, in fact do not always refer as proper names does. We provide an account explaining why, centered around the notion of "resource", central to webarch, and that we qualify ontologically

Nonmonotonic Integrity Constraints

Abstract. Semantics of multidimensional dynamic logic programming is traditionally based on the causal rejection principle: if there is a conflict between rules then the rule from a less preferred program is rejected. However, sometimes it is useful to solve a conflict between the heads of rules by blocking the body of a rule. Moreover, semantics based on the causal rejection principle, is not able to recognize conflicts, which are not manifested as conflicts between the heads of rules. Nonmonotonic integrity constraints are discussed in this paper. They provide alternative solutions of conflicts (as compared with solutions based on causal rejection principle). Conceptual apparatus introduced in this paper enables also to distinguish more preferred interpretations and, consequently, it is relevant for logic programming with preferences. Nonmonotonic integrity constraints and other notions introduced in the paper (falsified assumptions, more preferred assumptions) contribute to bridging the gap between research in fields as belief revision or preference handling on the one hand and multidimensional dynamic logic programming on the other hand

Formal argumentation and epistemic logic: what can they do for each other?

Arguing and believing are two central cognitive dimensions of both human beings and artificial intelligent agents. The interrelation of these two notions (or groups of notions) is at the root of classic debates in epistemology and argumentation theory. During this talk, we will critically review recent literature on combining two well-known families of formalisms that account respectively for argumentation and beliefs, these are, formal argumentation and epistemic logic. [...]Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

A first-order epistemic quantum computational semantics with relativistic-like epistemic effects

Quantum computation has suggested new forms of quantum logic, called quantum computational logics. In these logics well-formed formulas are supposed to denote pieces of quantum information: possible pure states of quantum systems that can store the information in question. At the same time, the logical connectives are interpreted as quantum logical gates: unitary operators that process quantum information in a reversible way, giving rise to quantum circuits. Quantum computational logics have been mainly studied as sentential logics (whose alphabet consists of atomic sentences and of logical connectives). In this article we propose a semantic characterization for a first-order epistemic quantum computational logic, whose language can express sentences like "Alice knows that everybody knows that she is pretty". One can prove that (unlike the case of logical connectives) both quantifiers and epistemic operators cannot be generally represented as (reversible) quantum logical gates. The "act of knowing" and the use of universal (or existential) assertions seem to involve some irreversible "theoretic jumps", which are similar to quantum measurements. Since all epistemic agents are characterized by specific epistemic domains (which contain all pieces of information accessible to them), the unrealistic phenomenon of logical omniscience is here avoided: knowing a given sentence does not imply knowing all its logical consequences