Formalizing defeasible argumentation using a labeled deductive system

Abstract

In the last years there has been and increasing demand of a variety of logical systems, prompted mostly by applications of logic in AI, logic programming an other related areas. Labeled Deductive Systems (LDS) were developed as a flexible methodology to formalize such a kind of complex logical systems. In the last decade, defeasible argumentation has proven to be a confluence point for many approaches to formalizing commonsense reasoning. Different formalisms have been developed, many of them sharing common features. This paper presents a formalization of an LDS for defeasible argumentation, in wich the main issues concerning defeasible argumentation are captured a unified logical framework.The propose framework is defined in two stages. First, defeasible inference will be formalized by characterizing and argumentative LDS. That system will be then extended in order to capture conflict among arguments using a dialectal approach. We also present some logical properties emerging from the proposed framework, discussing also its semantical characterization.