Modeling time and valuation in structured argumentation frameworks

Temporal Argumentation Frameworks (TAF) represent a recent extension of Dung's abstract argumentation frameworks that consider the temporal availability of arguments. In a TAF, arguments are valid during specific time intervals, called availability intervals, while the attack relation of the framework remains static and permanent in time; thus, in general, when identifying the set of acceptable arguments, the outcome associated with a TAF will vary in time. We introduce an extension of TAF, called Extended Temporal Argumentation Framework (E-TAF), adding the capability of modeling the temporal availability of attacks among arguments, thus modeling special features of arguments varying over time and the possibility that attacks are only available in a given time interval. E-TAF will be enriched by considering Structured Abstract Argumentation, using Dynamic Argumentation Frameworks. The resulting framework, E-TAF∗, provides a suitable model for different time-dependent issues satisfying properties and equivalence results that permit to contrast the expressivity of E-TAF and E-TAF∗ with argumentation based on abstract frameworks. Thus, the main contribution here is to provide an enhanced framework for modeling special features of argumentation varying over time, which are relevant in many real-world situations. The proposal aims at advancing in the integration of time and valuation in the context of argumentation systems as well.Fil: Budan, Maximiliano Celmo David. Universidad Nacional del Sur. Departamento de Ciencias e Ingeniería de la Computación; Argentina. Universidad Nacional de Santiago del Estero. Facultad de Ciencias Exactas y Tecnologías. Departamento de Matemática; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; ArgentinaFil: Gomez Lucero, Mauro Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Ciencias e Ingeniería de la Computación; ArgentinaFil: Chesñevar, Carlos Iván. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentina. Universidad Nacional de Santiago del Estero. Facultad de Ciencias Exactas y Tecnologías. Departamento de Matemática; Argentina. Universidad Nacional del Sur. Departamento de Ciencias e Ingeniería de la Computación; ArgentinaFil: Simari, Guillermo Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Ciencias e Ingeniería de la Computación; Argentin

An approach for Temporal Argumentation Using Labeled Defeasible Logic Programming (l-DeLP)

In the last decade, several argument-based formalisms have emerged, with application in many areas, such as legal reasoning, autonomous agents and multi-agent systems; many are based on Dung’s seminal work characterizing Abstract Argumentation Frameworks (AF). Recent research in the area has led to Temporal Argumentation Frameworks (TAF), that extend AF by considering the temporal availability of arguments. On the other hand, different more concrete argumentation systems exists, such as Defeasible Logic Programming (DeLP), specifying a knowledge representation language, and how arguments are built. In this work we combine time representation capabilities of TAF with the representation language and argument structure of DeLP, defining a rule-based argumentation framework that considers time at the object language level. In order to do this, we use an extension of DeLP, called Labeled DeLP (l-DeLP) to establish, for each program clause, the set of time intervals in which it is available, and to determine from this information the temporal availability of arguments. Acceptability semantics for TAF can then be applied to determine argument acceptability on timeFacultad de Informátic

Admissible sets of arguments in a timed context

Timed abstract frameworks (TAFs) are a novel formalism for argumentation where arguments are valid only during specific intervals of time, called availability intervals. Attacks between arguments are relevant only when both the attacker and the attacked arguments are available. Thus, the outcome of the framework may vary in time. Previous formalization of TAFs are based on discrete time, with single-interval argument validity. In this work we study argument admissibility notions in a timed abstract framework with intermittent arguments under a dense time representation.Sociedad Argentina de Informática e Investigación Operativ

On semantics in dynamic argumentation frameworks

A Timed Abstract Argumentation Framework is a novel formalism where arguments are only valid for consideration in a given period of time, which is defined for every individual argument. Thus, the attainability of attacks and defenses is related to time, and the outcome of the framework may vary accordingly. In this work we study the notion of stable extensions applied to timed-arguments. The framework is extended to include intermittent arguments, which are available with some repeated interruptions in time.XIV Workshop agentes y sistemas inteligentes.Red de Universidades con Carreras en Informática (RedUNCI

An approach for Temporal Argumentation Using Labeled Defeasible Logic Programming (l-DeLP)

In the last decade, several argument-based formalisms have emerged, with application in many areas, such as legal reasoning, autonomous agents and multi-agent systems; many are based on Dung’s seminal work characterizing Abstract Argumentation Frameworks (AF). Recent research in the area has led to Temporal Argumentation Frameworks (TAF), that extend AF by considering the temporal availability of arguments. On the other hand, different more concrete argumentation systems exists, such as Defeasible Logic Programming (DeLP), specifying a knowledge representation language, and how arguments are built. In this work we combine time representation capabilities of TAF with the representation language and argument structure of DeLP, defining a rule-based argumentation framework that considers time at the object language level. In order to do this, we use an extension of DeLP, called Labeled DeLP (l-DeLP) to establish, for each program clause, the set of time intervals in which it is available, and to determine from this information the temporal availability of arguments. Acceptability semantics for TAF can then be applied to determine argument acceptability on timeFacultad de Informátic

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