Multi-Agent Abstract Argumentation Frameworks With Incomplete Knowledge of Attacks

Abstract

We introduce a multi-agent, dynamic extension of abstract argumentation frameworks (AFs), strongly inspired by epistemic logic, where agents have only partial information about the conflicts between arguments. These frameworks can be used to model a variety of situations. For instance, those in which agents have bounded logical resources and therefore fail to spot some of the actual attacks, or those where some arguments are not explicitly and fully stated (enthymematic argumentation). Moreover, we include second-order knowledge and common knowledge of the attack relation in our structures (where the latter accounts for the state of the debate), so as to reason about different kinds of persuasion and about strategic features. This version of multi-agent AFs, as well as their updates with public announcements of attacks (more concretely, the effects of these updates on the acceptability of an argument) can be described using S5-PAL, a well-known dynamic-epistemic logic. We also discuss how to extend our proposal to capture arbitrary higher-order attitudes and uncertainty.

Qualitative uncertainty and dynamics of argumentation through dynamic logic

“…In recent years, a few papers dealing with the combination of epistemic logic and formal argumentation have appeared. Broadly speaking, these works can be divided into two main branches: (i) those trying to provide a formalisation of the notion of justified belief based on argumentative tools such as [44,62,63,61,21,22]; and (ii) those using epistemic models for reasoning about uncertain AFs such as [60,59,49,50]. Clearly, the second one is strongly connected-both conceptually and technically-to some of the ideas presented here.…”

“…One of the appealing features of IAFs is that they admit a very intuitive graphic representation (see Example 1). Interestingly, rIAFs and d-arg-IAFs can also be fully represented in a pictorial manner; see [49] for examples with d-arg-IAFs. As pointed out in [53], cIAFs JM only admit a partial graphic representation.…”