t-DeLP: An argumentation-based Temporal Defeasible Logic Programming framework

The aim of this paper is to propose an argumentation-based defeasible logic, called t-DeLP, that focuses on forward temporal reasoning for causal inference. We extend the language of the DeLP logical framework by associating temporal parameters to literals. A temporal logic program is a set of basic temporal facts and (strict or defeasible) durative rules. Facts and rules combine into durative arguments representing temporal processes. As usual, a dialectical procedure determines which arguments are undefeated, and hence which literals are warranted, or defeasibly follow from the program. t-DeLP, though, slightly differs from DeLP in order to accommodate temporal aspects, like the persistence of facts. The output of a t-DeLP program is a set of warranted literals, which is first shown to be non-contradictory and be closed under sub-arguments. This basic framework is then modified to deal with programs whose strict rules encode mutex constraints. The resulting framework is shown to satisfy stronger logical properties like indirect consistency and closure. © 2013 Springer Science+Business Media Dordrecht.This work has been partially supported by the Spanish MICINN projects CONSOLIDER-INGENIO 2010 Agreement Technologies CSD2007-00022 and ARINF TIN2009-14704-C03-03, with FEDER funds of the EU, and by the Generalitat de Catalunya grant 2009-SGR-1434Peer Reviewe

Policies, norms and actions: groundwork for a framework

Constraints on computational agents' behaviour are studied both in work on policy- governed systems|usually as part of work on security or policy-based management in dis- tributed software engineering|and also in multi-agent systems research, where the terminol- ogy is generally one of `norms' and concepts drawn from deontic logic. Interaction between these treatments, and the research communities that study them, has not been as thorough as it might, for though the perpectives, methods and interests are sometimes di erent, there is a great deal of shared ground. In the current research report, we present a language and tools which can be used for reasoning about and studying the operation of both norms and policies on a multi-agent, or distributed, system. The language is based on one member, C+, of a family of knowledge representation formalisms studied in AI. We describe the types of domains that can be represented, the kinds of analysis tasks that are possible, and describe our current implementation (which is freely available for download). Future directions for this work are described

(C+)++: An action language for modelling norms and institutions

The language C+ of Giunchiglia, Lee, Lifschitz, McCain, and Turner (2004) is a formalism for specifying and reasoning about the e ects of actions and the persistence (`inertia') of facts over time. An `action description' in C+ is a set of C+ laws which de ne a labelled transition system of a certain kind. This document presents (C+)++, an extended form of C+ designed for representing norms of behaviour and institutional aspects of (human or computer) societies. There are two main extensions. The rst is a means of expressing `counts as' relations between actions, also referred to as `conventional generation' of actions. The second is a way of specifying the permitted (acceptable, legal) states of a transition system and its permitted (acceptable, legal) transitions