The need for negotiation in multi-agent systems stems from the requirement for agents to solve the problems posed by their interdependence upon one another. Negotiation provides a solution to these problems by giving the agents the means to resolve their conflicting objectives, correct inconsistencies in their knowledge of other agents' world views, and coordinate a joint approach to domain tasks which benefits all the agents concerned. We propose a framework, based upon a system of argumentation, which permits agents to negotiate in order to establish acceptable ways of solving problems. The framework provides a formal model of argumentation-based reasoning and negotiation, details a design philosophy which ensures a clear link between the formal model and its practical instantiation, and describes a case study of this relationship for a particular class of architectures (namely those for belief-desire-intention agents). 1 Introduction An increasing number of software app...

In the area of agent-based computing there are many proposals for specific system architectures, and a number of proposals for general approaches to building agents. As yet, however, there are comparatively few attempts to relate these together, and even fewer attempts to provide methodologies which relate designs to architectures and then to executable agents. This paper provides a first attempt to address this shortcoming. We propose a general method of specifying logic-based agents, which is based on the use of multi-context systems, and give examples of its use. The resulting specifications can be directly executed, and we discuss an implementation which makes this direct execution possible.

METATEM is a simple programming language based on the direct execution of temporal logic statements. It was introduced through a number of papers [35,2,3] culminating in a book collecting together work on the basic temporal language [5]. However, since that time, there has been a programme of research, carried out over a number of years,

The goal of this paper is to provide a formalization of monotonic belief and belief about belief in a multiagent environment. We distinguish between ideal beliefs, i.e., those beliefs which satisfy certain "idealized" properties which are unlikely to be possessed by real agents, and real beliefs. Our formalization is based on a set-theoretic specification of beliefs and, then, on the definition of the appropriate constructors which present the sets identified. This allows us to provide a uniform and taxonomic characterization of the possible ways in which ideal and real beliefs can arise. We provide intuitions about the conceptual importance of the cases analyzed by proving and discussing some equivalence results with some important modal systems modeling various forms of (non) logical omniscience. 1 Introduction We are interested in the formalization of monotonic belief and belief about belief in a multiagent environment. Here, we restrict ourselves to the propositional case. We dis...

This paper discusses the uses of context in knowledge representation and reasoning (KRR). We propose to partition the theories of context brought forward in KRR into two main classes, which we call divide-and-conquer and compose-and-conquer. We argue that this partition provides a possible explanation of why in KRR context is used to solve dierent types of problems, or to address the same problems from very dierent perspectives. The problems we use to illustrate this point are the problem of generality, the formalization of propositional attitudes, knowledge and data integration.

In this paper a compositional model for reflective agents is proposed within which reasoning about observation, assumption making and communication; an agent's own information state and reasoning processes; other agents' information states and reasoning processes, and combinations of these types of reflective reasoning are explicitly modelled. The types of knowledge needed to detect, analyse and resolve conflicts that arise by meta-reasoning within the agent are discussed. The knowledge

In the last decade the concept of context has been extensively exploited in many research areas, e.g., distributed artificial intelligence, multi agent systems, distributed databases, information integration, cognitive science, and epistemology. Three alternative approaches to the formalization of the notion of context have been proposed: Giunchiglia and Serafini's Multi Language Systems (ML systems), McCarthy's modal logics of contexts, and Gabbay's Labelled Deductive Systems. Previous papers have argued in favor of ML systems with respect to the other approaches. Our aim in this paper is to support these arguments from a theoretical perspective. We provide a very general definition of ML systems, which covers all the ML systems used in the literature, and we develop a proof theory for an important subclass of them: the MR systems. We prove various important results; among other things, we prove a normal form theorem, the sub-formula property, and the decidability of an important instance of the class of the MR systems. The paper concludes with a detailed comparison among the alternative approaches.

. The formalization of agents attitudes, and belief in particular, has been investigated in the past by the authors of this paper, along two different but related streams. Giunchiglia and Giunchiglia investigate the properties of contexts for the formal specification of agents mutual beliefs, combining extensional specification with (finite) presentation by means of contexts. Cimatti and Serafini address the representational and implementational implications of the use of contexts for representing propositional attitudes by tackling a paradigmatic case study. The goal of this paper is to show how these two streams are actually complementary, i.e. how the methodology proposed in the former can be successfully applied to formally specify the case study discussed in the latter. In order to achieve this goal, the formal framework is extended to take into account some relevant aspects of the case study, the specification of which is then worked out in detail. 1 Introduction Much of the wor...

In this paper a knowledge-level model of an individual designer as an agent is described, in which reflective reasoning about elements of situatedness, and reasoning from the point of view of other participants, are explicitly modelled. This model is based on existing models of single agent design. An individual designer in a specific distributed design process, namely website design, is used to illustrate the model.

. In this paper we propose to re-read the past work on formalizing context as the search for a logic of the relationships between partial, approximate, and perspectival theories of the world. The idea is the following. We start from a very abstract analysis of a context dependent representation into three basic elements. We briey show that all the mechanisms of contextual reasoning that have been studied in the past fall into three abstract forms: expand/contract, push/pop, and shifting. Moreover we argue that each of the three forms of reasoning actually captures an operation on a dierent dimension of variation of a context dependent representation, partiality, approximation, and perspective. We show how these ideas are formalized in the framework of MultiContext Systems, and briey illustrate some applications. 1