This paper presents a new logic programming language for modelling Agents and Multi-Agent systems in computational logic. The basic objective of the specification of this new language has been the identification and the formalization of what we consider to be the basic patterns for reactivity, proactivity, internal "thinking", and "memory".

Agent-based computing is an emerging computing paradigm that has proved extremely successful in dealing with a number of problems arising from new technological developments and applications. In this paper we report the role of computational logic in modeling intelligent agents, by analysing existing agent theories, agent-oriented programming languages and applications, as well as identifying challenges and promising directions for future research. 1 Introduction In the past ten years the eld of agent-based computing has emerged and greatly expanded, due to new technological developments such as ever faster and cheaper computers, fast and reliable interconnections between them as well as the emergence of the world wide web. These developments have at the same time opened new application areas, such as electronic commerce, and posed new problems, such as that of integrating great quantities of information and building complex software, embedding legacy code. The establishment o...

this paper we propose a combination of the dynamic logic programming paradigm and (a version of) KS-agents. In the resulting framework, rational, reactive agents can dynamically change their own knowledge bases as well as their own goals. In particular, at every iteration of an observe-think-act cycle, the agent can make observations, learn new facts and new rules from the environment, and then it can update its knowledge accordingly.

In this paper we present the new logic programming language DALI, aimed at defining agents and agent systems. A main design objective for DALI has been that of introducing in a declarative fashion all the essential features, while keeping the language as close as possible to the syntax and semantics of the plain Horn--clause language. Special atoms and rules have been introduced, for representing: external events, to which the agent is able to respond (reactivity); actions (reactivity and proactivity); internal events (previous conclusions which can trigger further activity); past and present events (to be aware of what has happened). An extended resolution is provided, so that a DALI agent is able to answer queries like in the plain Horn--clause language, but is also able to cope with the different kinds of events, and exhibit a (rational) reactive and proactive behaviour. 1 Introduction In this paper we address the issue of defining a logic programming language for reac...

a computational logic model for the description, analysis and verification of global and open societies of heterogeneous computees IST-2001-32530 Deliverable D4: A logic-based approach to model computees Project number:

We present the basic principles and possible applications of systems capable of meta-reasoning and reflection. After a discussion of the seminal approaches, we outline our own perception of the state of the art, mainly but not only in computational logic and logic programming. We review relevat successful...

We present an approach to agents that can reason, react to the environment and are able to update their own knowledge as a result of new incoming information. Each agents' view of the social relationships among agents (itself and others) is represented by a graph, which in turn can be updated, allowing for the representation of such social evolution.

This paper presents a language for coordinating several logic-based agents capable of abductive reasoning. The system is particularly suited for solving problems with incomplete knowledge, where agents may need to make reasonable hypotheses about the domain. We defined a simple declarative language to express agent behavior, and in particular, two forms of coordination: collaboration and competition. An example in the area of medical diagnosis is presented to show the features of the language and the behavior of the proposed architecture. 1

Abstract. Most existing work on belief revision and knowledge representation and reasoning tacitly assumes that belief revision is performed off-line, and that reasoning from the beliefs is performed either before or after the beliefs are changed. This imposes that, if a revision occurs while reasoning is performed, reasoning has to be stopped and re-started anew so that the revision is taken into account, with an obvious wastage of reasoning effort. In this paper, we tackle the problem of performing belief revision on-line, while reasoning is taking place by means of an abductive proof procedure. 1

this paper we propose a combination of (a version of) the RPC programming paradigm and KS-agents. In the resulting framework reactive, rational or hybrid agents can reason about their own beliefs as well as the beliefs of other agents and can communicate proactively with each other. In such a framework, the agents' behaviour can be regulated by condition-action rules such as: if I am asked by another, friendly agent about something and I can prove it from my beliefs then I will tell the agent about it. In the proposed approach, we adopt two primitives for communication, tell