. A process of team formation by autonomous agents in a distributed environment is presented. Since the environment is distributed, there are serious problems with communication and consistent decision making inside a team. To deal with these problems, the standard technique of token passing in a computer network is applied. The passing cycle of the token serves as the communication route. It assures consistent decision making inside the team maintaining its organizational integrity. On the other hand it constitutes a component of the plan of the cooperative work performed by a complete team. Two algorithms for team formation are given. The first one is based on simple self-interested agents that still can be viewed as reactive agents (see [14]) although augmented with knowledge, goal, and cooperation mechanisms. The second one is based on sophisticated self-interested agents. Moreover, the algorithm based on fully cooperative agents, which is an adaptation of the static ...

A concurrent version of a finite-state automaton is a set of processes that cooperate in processing letters of the input. Each letter read prompts some of the processes to synchronize and decide on a joint move according to a non-deterministic transition relation. Such automata are known as asynchronous automata. The question whether these automata can be determinized while retaining the synchronization structure has already been answered in the positive, but indirectly, by means of sophisticated algebraic techniques. In this paper we present an elementary proof, which generalizes the classic subset construction for finite-state automata. The proof uses in an essential way an earlier finite-state construction by Mukund and Sohoni for maintaining each process's latest knowledge about other processes. Our construction is only double-exponential and thus is the first to essentially match the lower bound. Computer Science Department, Aarhus University, Ny Munkegade, DK 8000 Aarhus C, ...

. Temporal logic of causal knowledge over general partially ordered structures is defined. The definition of knowledge captures the change of state due to action executions. The structures are a variant of flow event structures including prime event structures and branching processes of Petri Nets. Modalities corresponding to the causality, independency, and indistinguishability relations are used. Formulas are interpreted over local state occurrences. The logic is proved to be decidable and a complete axiomatization is provided. Keywords: multi-agent systems, knowledge, temporal logic, causality, partially ordered sets. 1 Introduction Reasoning about knowledge is one of the fundamental problems in multi-agent systems. Usually, dynamic global state spaces partitioned w.r.t. the agents' information are considered [3]. In the theory of distributed systems, knowledge formulas are interpreted over infinite linear or branching runs of the systems [4, 5, 3, 9, 15, 16]. It is clear ...

We tackle a natural problem from distributed computing, involving time-stamps. Let P = fp 1 ; p 2 ; : : : ; p N g be a set of computing agents or processes which synchronize with each other from time to time and exchange information about themselves and others. The gossip problem is the following: Whenever a set P ` P meets, the processes in P must decide amongst themselves which of them has the latest information, direct or indirect, about each agent p in the system. We propose an algorithm to solve this problem which is finite-state and local. Formally, this means that our algorithm can be implemented as an asynchronous automaton.

We propose trace event structures as a starting point for constructing effective branching time temporal logics in a non-interleaved setting.

In this paper, we first tackle a natural problem from distributed computing, involving time-stamps. We then show that our solution to this problem can be applied to provide a simplified proof of Zielonka's theorem---a fundamental result in the theory of concurrent systems. Let P = fp 1 ; p 2 ; : : : ; p N g be a set of computing agents or processes which synchronize with each other from time to time and exchange information about themselves and others. The gossip problem is the following: Whenever a set P ` P meets, the processes in P must decide amongst themselves which of them has the latest information, direct or indirect, about each agent p in the system. We propose an algorithm to solve this problem which is finite-state and local. Formally, this means that our algorithm can be implemented as an asynchronous automaton. Solving the gossip problem appears to be a basic step in tackling other problems involving asynchronous automata. Here, we apply our solution to derive...

Temporal logic of causal knowledge over general partially ordered structures of local states is dened. The denition of knowledge captures the change of state due to action executions. The structures are a variant of ow event structures including prime event structures and branching processes of Petri Nets. Modalities corresponding to the causality, concurrency, and indistinguishability relations are used. Formulas are interpreted over local state occurrences. The logic is proved to be decidable and a complete axiomatization is provided. 1 Keywords: multi-agent systems, knowledge, temporal logic, causality, partially ordered sets. 1 Introduction Reasoning about knowledge is one of the fundamental problems in multi-agent systems. Usually, dynamic global state spaces partitioned w.r.t. the agents' information are considered [5]. In the theory of distributed systems, knowledge formulas are interpreted over innite linear or branching runs of the systems [8, 9, 5, 13, 20, 21]. It is cle...

A model checking algorithm for a variant of the temporal logic of causal knowledge [25] is given. The temporal language is interpreted over labelled prime event structures. Knowledge operators express agents' history knowledge and the knowledge acquired about other agents. The temporal modalities correspond to the immediate causality and causality. For systems represented by deterministic Asynchronous Automata we prove that the complexity of the model checking algorithm for formula ' over automaton A of N-agents is j'j \Theta jAj \Theta jGA j \Theta 2 O(N 3 logN) , where jGA j is the size of the global state space of A and A is the alphabet of actions. Partial order reductions are used in order to make the model checking algorithm more efficient. 1 Introduction In the theory of distributed systems, knowledge formulas are usually interpreted over infinite linear or branching runs of global states of the systems [12,13,11,16,26,27]. It is clear that capturing changes in state due t...

A formal framework for specification and verification of multi-agent systems is developed. Specification of an infrastructure created by a mobile agent platform is presented. On the basis of the specification, the notions of common ontology core, and agent's knowledge are introduced. A simple agent architecture is presented. Given agents' knowledge and decision mechanisms, model checking method is applied to verify whether the agents can realize their goals. 1

. In the paper we present our work on design and analysis of agent cooperation in distributed systems. The work is not completed yet, so that some parts of it, especially the formal framework, should be viewed as a preliminary version. Multi-agent systems are represented by BDI-automata, i.e., asynchronous automata composed of non-deterministic agents equipped with mental attitudes like belief, desire, and intentions. These attitudes are acquired by the agents by executing so called mental actions. Behaviours of multi-agent systems are represented by prime event structures. The prime event structure when augmented with utility functions defined on the terminal nodes of the structure may be viewed as games in extensive form defined on local states rather than on global states as in the classical definition. The definition of knowledge, in our framework, captures the change of state due to action executions. A notion of local knowledge-based protocols is defined. A game theory method of ...