Strategic Abilities of Asynchronous Agents: Semantic Side Effects and How to Tame Them

Recently, we have proposed a framework for verification of agents' abilities in asynchronous multi-agent systems, together with an algorithm for automated reduction of models. The semantics was built on the modeling tradition of distributed systems. As we show here, this can sometimes lead to counterintuitive interpretation of formulas when reasoning about the outcome of strategies. First, the semantics disregards finite paths, and thus yields unnatural evaluation of strategies with deadlocks. Secondly, the semantic representations do not allow to capture the asymmetry between proactive agents and the recipients of their choices. We propose how to avoid the problems by a suitable extension of the representations and change of the execution semantics for asynchronous MAS. We also prove that the model reduction scheme still works in the modified framework

On Global Types and Multi-Party Session

Global types are formal specifications that describe communication protocols in terms of their global interactions. We present a new, streamlined language of global types equipped with a trace-based semantics and whose features and restrictions are semantically justified. The multi-party sessions obtained projecting our global types enjoy a liveness property in addition to the traditional progress and are shown to be sound and complete with respect to the set of traces of the originating global type. Our notion of completeness is less demanding than the classical ones, allowing a multi-party session to leave out redundant traces from an underspecified global type. In addition to the technical content, we discuss some limitations of our language of global types and provide an extensive comparison with related specification languages adopted in different communities

Rules of the Road: Towards Safety and Liveness Guarantees for Autonomous Vehicles

The ability to guarantee safety and progress for all vehicles is vital to the success of the autonomous vehicle industry. We present a framework for the distributed control of autonomous vehicles that is safe and guarantees progress for all agents. In this paper, we first introduce a new game paradigm which we term the quasi-simultaneous discrete-time game. We then define an Agent Protocol agents must use to make decisions in this quasi-simultaneous discrete-time game setting. According to the protocol, agents first select an intended action and then each agent determines whether it can take its intended action or not, given its proposed intention and the intentions of nearby agents. The protocol so defined will ensure safety under all traffic conditions and liveness for all agents under "sparse" traffic conditions. These guarantees, however, are predicated on the premise that all agents are operating with the aforementioned protocol. We provide proofs of correctness of the protocol and validate our results in simulation

Requirements, Formal Verification and Model transformations of an Agent-based System: A CASE STUDY

One of the most challenging tasks in software specifications engineering for a multi-agent system is to ensure correctness. As these systems have high concurrency, often have dynamic environments, the formal specification and verification of these systems along with step-wise refinement from abstract to concrete concepts play major role in system correctness. Our objectives are the formal specification, analysis with respect to functional as well as non-functional properties by step-wise refinement from abstract to concrete specifications and then formal verification of these specifications. A multi-agent system is concurrent system with processes working in parallel with synchronization between them. We have worked on Gaia multi-agent method along with finite state process based finite automata techniques and as a result we have defined the formal specifications of our system, checked the correctness and verified all possible flow of concurrent executions of these specifications. Our contribution consists in transforming requirement specifications based on organizational abstractions into executable formal verification specifications based on finite automata. We have considered a case study of our multi-agent system to exemplify formal specifications and verification. Keywords: Multi-Agent System, Agent Models and Architecture, Gaia multi-agent method, Formal methods, Formal verification, Finite State Process (FSP), Labelled Transition System (LTS), Labelled Transition System Analyzer (LTSA), Safety property, Liveness propert

Requirements, Formal Verification and Model transformations of an Agent-based System: A CASE STUDY

One of the most challenging tasks in software specifications engineering for a multi-agent system is to ensure correctness. As these systems have high concurrency, often have dynamic environments, the formal specification and verification of these systems along with step-wise refinement from abstract to concrete concepts play major role in system correctness. Our objectives are the formal specification, analysis with respect to functional as well as non-functional properties by step-wise refinement from abstract to concrete specifications and then formal verification of these specifications. A multi-agent system is concurrent system with processes working in parallel with synchronization between them. We have worked on Gaia multi-agent method along with finite state process based finite automata techniques and as a result we have defined the formal specifications of our system, checked the correctness and verified all possible flow of concurrent executions of these specifications. Our contribution consists in transforming requirement specifications based on organizational abstractions into executable formal verification specifications based on finite automata. We have considered a case study of our multi-agent system to exemplify formal specifications and verification.Comment: 16 pages; Computer Engineering and Intelligent Systems http://www.iiste.org - ISSN 2222-1719 (Paper) ISSN 2222-2863 (Online) - Vol.5, No.3, 201