Operations on admissible attack scenarios

In classical abstract argumentation, arguments interact with each other through a single abstract notion of attack. However, several concrete forms of argument conflict are present in the literature, all of them of different nature and strength for a particular context. In this work we define an argumentation framework equipped with a set of abstract attack relations of varied strength. Using this framework, semantic notions dealing with the relative difference of strength are introduced. The focus is put on argument defense, and the study of admissible sets according to the quality of defenders.Presentado en el X Workshop Agentes y Sistemas InteligentesRed de Universidades con Carreras en Informática (RedUNCI

The role of argument comparison in dialectical argumentation

There are a lot argumentation models thal have been developed inside Artificial Intelligence. Among these models, differents formal systems of defeasible argumentation are defined, where arguments for and against a proposition are produced and evaluated to verify the acceptabilily of that proposition. In this manner, defeasible argumentation allows reasoning with incomplele and uncertain information. The development of this kind of systems has grown in the last years [SIM92, BART, KOWA96, AG97, DUNG93, DUNGLP] but no consensus has been reached yet on some issues, such as the representation of arguments, the way they interact, and the output of that interaction. Even then, the main idea in these systems is that any proposition will be accepted as true if there exist an argument that supports it, and this argument is acceptable according to an analysis between it and its counterarguments. Therefore, in the set of arguments of the system, some of them will be "acceptable" or "justified" arguments, while others not. But this bi-valued classification" arguments is not enough, due to some situations that can be found in argumentation systems. The reasons of non-justification can be analyzed in more detail, so we can make a more specific classification the non-justified arguments. An argument of this kind can not be justified because, for instance, it has a justified defeater, it is involved in circular argumentation. In the former, we can think that the argument has been effectively defeated. In the lalter, the juslification of the argument falls in an "inconclusive" state. This is the starting point lo distinguish a third kind of arguments: those which left the dispute without any conclusion. There exist various names for this argulments, like defendibles, undecided, ambiguous and undetermined. In the rest the paper, we will call this arguments undecided. There is another reason to classify an argument as undecided. This reason is not so obvious as the one specified above, and is related to the comparison of arguments.Eje: Aspectos teóricos de inteligencia artificialRed de Universidades con Carreras en Informática (RedUNCI

Defining the structure of well-formed argumentation lines in abstract frameworks

The area of Knowledge Representation and Reasoning has been enriched during the past two decades with the addition of Argument-Based Reasoning Systems. Defeat between arguments is established by a combination of two basic elements: a conflict or defeat relation, and a preference relation on the arguments involved in this conflict. The research activities are centered in our abstract framework for argumentation, where two kinds of defeat are present, depending on the outcome of the preference relation. This framework also takes subarguments into account, leading to the formalization of well formed argumentation lines.Eje: Agentes y Sistemas InteligentesRed de Universidades con Carreras en Informática (RedUNCI

Well-formed defeat paths in abstract argumentation frameworks

Abstract argumentation systems are formalisms for argumentation where some components remains unspecified, usually the structure of arguments. In the dialectical process carried out to identify accepted arguments in the system, some controversial situations may be found, related to the reintroduction of arguments in this process, causing a circularity that must be treated in order to avoid an infinite analysis. Some systems apply a single restriction to argumentation lines: no previously considered argument is reintroduced in the process. In this work we show that a more specific restriction need to be applied, taking subarguments into account. We finally present a new definition of acceptable argumentation linesVI Workshop de Agentes y Sistemas Inteligentes (WASI)Red de Universidades con Carreras en Informática (RedUNCI

Defining the structure of well-formed argumentation lines in abstract frameworks

The area of Knowledge Representation and Reasoning has been enriched during the past two decades with the addition of Argument-Based Reasoning Systems. Defeat between arguments is established by a combination of two basic elements: a conflict or defeat relation, and a preference relation on the arguments involved in this conflict. The research activities are centered in our abstract framework for argumentation, where two kinds of defeat are present, depending on the outcome of the preference relation. This framework also takes subarguments into account, leading to the formalization of well formed argumentation lines.Eje: Agentes y Sistemas InteligentesRed de Universidades con Carreras en Informática (RedUNCI

Well-formed defeat paths in abstract argumentation frameworks

Abstract argumentation systems are formalisms for argumentation where some components remains unspecified, usually the structure of arguments. In the dialectical process carried out to identify accepted arguments in the system, some controversial situations may be found, related to the reintroduction of arguments in this process, causing a circularity that must be treated in order to avoid an infinite analysis. Some systems apply a single restriction to argumentation lines: no previously considered argument is reintroduced in the process. In this work we show that a more specific restriction need to be applied, taking subarguments into account. We finally present a new definition of acceptable argumentation linesVI Workshop de Agentes y Sistemas Inteligentes (WASI)Red de Universidades con Carreras en Informática (RedUNCI

Acceptability semantics and contextual defeat relations in extended frameworks

In this work, contexts for extended argumentation frameworks (EAF) are defined. A context for an EAF is another framework where original arguments, conflicts and preferences are kept, while introducing new arguments leading to new defeat relations. Thus, the context may interfere with the original classification of arguments, inducing new set of extensions. These semantic change in the outcome of an extended framework in a particular context is characterized, and Dung’s acceptability concept is analyzed on this basis.Red de Universidades con Carreras en Informática (RedUNCI

An approach to knowledge dynamic maintenance for emotional agents

In this work we present an approach to emotional reasoning for believable agents, by introducing a mechanism to progressively build a map of knowledge for reasoning. We present the notion of inference graph for progressive reasoning in an emotional context. In this model, knowledge is partially highlighted and noticed by the agent.Sociedad Argentina de Informática e Investigación Operativa (SADIO

An approach to knowledge dynamic maintenance for emotional agents

In this work we present an approach to emotional reasoning for believable agents, by introducing a mechanism to progressively build a map of knowledge for reasoning. We present the notion of inference graph for progressive reasoning in an emotional context. In this model, knowledge is partially highlighted and noticed by the agent.Sociedad Argentina de Informática e Investigación Operativa (SADIO