52, Argumentative Agent Deliberation, Roles and Context

This paper ('Argumentative Agent Deliberation, Roles and Context', 2002, Antonis Kakas and Pavlos Moraitis) presents an argumentation based framework based on 'Logic Programming without Negation as Failure' that makes use of three levels of rules (in the examples at least); 'object-level decision rules', 'role (or default context) priorities' and '(specific) context priorities'. Hints at using abduction for agents to make assumptions under incomplete knowledge but I didn't quite get it. Good deliberation examples making use of rules, priorities over rules and priorities over priorities over rules.