María Laura Cobo

Acceptability in Timed Frameworks with Intermittent Arguments

In this work we formalize a natural expansion of timed argumentation frameworks by considering arguments that are available with (possibly) some repeated interruptions in time, called intermittent arguments. This framework is used as a modelization of argumentation dynamics. The notion of acceptability of arguments is analyzed as the framework evolves through time, and an algorithm for computing intervals of argument defense is introduced.

Stable extensions in timed 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.

Bipolarity in temporal argumentation frameworks

A Timed Argumentation Framework (TAF) is a formalism where arguments are only valid for consideration during specific intervals of time, called availability intervals, which are defined for every individual argument. The original proposal is based on a single abstract notion of attack between arguments that remains static and permanent in time. Thus, in general, when identifying the set of acceptable arguments, the outcome associated with a TAF will vary over time.Here, we are introducing an extension of TAF adding the capability of modeling a support relation between arguments. In this sense, the resulting framework provides a suitable model for different time-dependent issues; thus, the main contribution of this work is to provide an enhanced framework for modeling a positive (support) and negative (attack) interaction which varies over time, features that are highly relevant in many real-world situations. This addition leads to a Timed Bipolar Argumentation Framework (T-BAF), where classical argument extensions can be defined, aiming at advancing in the integration of temporal argumentation in different application domains. Bipolar frameworks are equipped with temporal availability for arguments.Admissibility-based extensions for timed argumentation are characterized.Several relations between semantics in timed argumentation are presented.Relations between the classic bipolar and extension-based semantics are studied for BAFs.

An Approach to Characterize Topic-Centered Argumentation

As we engage in a debate with other parties, it is usual that several subjects might come under discussion. In this work, we propose an extension of classic abstract argumentation frameworks which includes a set of interrelated topics decorating arguments. These topics represent what the arguments are addressing and provide a supporting structure for the analysis of multi-topic argumentation. A notion of “proximity” of an argument to the focus of the debate is introduced, leading to a notion of distance between the topics of the arguments, which is used for proximity-based semantic elaborations.

A Petri Net Model of Argumentation Dynamics

Petri nets are a mathematical modelling tool suitable for describing dynamic computational systems. In this work we present a formalization of abstract argumentation frameworks using Petri nets, where arguments and attacks are represented as places and transitions. This provides a formalism to study the semantic consequences of a procedural evaluation of argument attacks. The relation between markings of the net and argument extensions is analysed.