MCMAS-SLK: A Model Checker for the Verification of Strategy Logic Specifications

We introduce MCMAS-SLK, a BDD-based model checker for the verification of systems against specifications expressed in a novel, epistemic variant of strategy logic. We give syntax and semantics of the specification language and introduce a labelling algorithm for epistemic and strategy logic modalities. We provide details of the checker which can also be used for synthesising agents' strategies so that a specification is satisfied by the system. We evaluate the efficiency of the implementation by discussing the results obtained for the dining cryptographers protocol and a variant of the cake-cutting problem

A synergistic and extensible framework for multi-agent system verification

Recently there has been a proliferation of tools and languages for modeling multi-agent systems (MAS). Verification tools, correspondingly, have been developed to check properties of these systems. Most MAS verification tools, however, have their own input language and often specialize in one verification technology, or only support checking a specific type of property. In this work we present an extensible framework that leverages mainstream verification tools to successfully reason about various types of properties. We describe the verification of models specified in the Brahms agent modeling language to demonstrate the feasibility of our approach. We chose Brahms because it is used to model real instances of interactions between pilots, air-traffic controllers, and automated systems at NASA. Our framework takes as input a Brahms model along with a Java implementation of its semantics. We then use Java PathFinder to explore all possible behaviors of the model and, also, produce a generalized intermediate representation that encodes these behaviors. The intermediate representation is automatically transformed to the input language of mainstream model checkers, including PRISM, SPIN, and NuSMV allowing us to check different types of properties. We validate our approach on a model that contains key elements from the Air France Flight 447 acciden

Bounded Model Checking for Parametric Timed Automata

Abstract. The paper shows how bounded model checking can be ap-plied to parameter synthesis for parametric timed automata with con-tinuous time. While it is known that the general problem is undecidable even for reachability, we show how to synthesize a part of the set of all the parameter valuations under which the given property holds in a model. The results form a complete theory which can be easily applied to parametric verification of a wide range of temporal formulae – we present such an implementation for the existential part of CTL −X. 1 Introduction and related work The growing abundance of complex systems in real world, and their presence in critical areas fuels the research in formal specification and analysis. One of the established methods in systems verification is model checking, where the system is abstracted into the algebraic model (e.g. various versions of Kripke structures

Verification of Agent-Based Artifact Systems

Artifact systems are a novel paradigm for specifying and implementing business processes described in terms of interacting modules called artifacts. Artifacts consist of data and lifecycles, accounting respectively for the relational structure of the artifacts' states and their possible evolutions over time. In this paper we put forward artifact-centric multi-agent systems, a novel formalisation of artifact systems in the context of multi-agent systems operating on them. Differently from the usual process-based models of services, the semantics we give explicitly accounts for the data structures on which artifact systems are defined. We study the model checking problem for artifact-centric multi-agent systems against specifications written in a quantified version of temporal-epistemic logic expressing the knowledge of the agents in the exchange. We begin by noting that the problem is undecidable in general. We then identify two noteworthy restrictions, one syntactical and one semantical, that enable us to find bisimilar finite abstractions and therefore reduce the model checking problem to the instance on finite models. Under these assumptions we show that the model checking problem for these systems is EXPSPACE-complete. We then introduce artifact-centric programs, compact and declarative representations of the programs governing both the artifact system and the agents. We show that, while these in principle generate infinite-state systems, under natural conditions their verification problem can be solved on finite abstractions that can be effectively computed from the programs. Finally we exemplify the theoretical results of the paper through a mainstream procurement scenario from the artifact systems literature

Logic-based Technologies for Multi-agent Systems: A Systematic Literature Review

Precisely when the success of artificial intelligence (AI) sub-symbolic techniques makes them be identified with the whole AI by many non-computerscientists and non-technical media, symbolic approaches are getting more and more attention as those that could make AI amenable to human understanding. Given the recurring cycles in the AI history, we expect that a revamp of technologies often tagged as “classical AI” – in particular, logic-based ones will take place in the next few years. On the other hand, agents and multi-agent systems (MAS) have been at the core of the design of intelligent systems since their very beginning, and their long-term connection with logic-based technologies, which characterised their early days, might open new ways to engineer explainable intelligent systems. This is why understanding the current status of logic-based technologies for MAS is nowadays of paramount importance. Accordingly, this paper aims at providing a comprehensive view of those technologies by making them the subject of a systematic literature review (SLR). The resulting technologies are discussed and evaluated from two different perspectives: the MAS and the logic-based ones

Recent advances in petri nets and concurrency

CEUR Workshop Proceeding

Arrows for knowledge-based circuits

Knowledge-based programs (KBPs) are a formalism for directly relating agents' knowledge and behaviour in a way that has proven useful for specifying distributed systems. Here we present a scheme for compiling KBPs to executable automata in finite environments with a proof of correctness in Isabelle/HOL. We use Arrows, a functional programming abstraction, to structure a prototype domain-specific synchronous language embedded in Haskell. By adapting our compilation scheme to use symbolic representations we can apply it to several examples of reasonable size

FLACOS’08 Workshop proceedings

The 2nd Workshop on Formal Languages and Analysis of Contract-Oriented Software (FLACOS’08) is held in Malta. The aim of the workshop is to bring together researchers and practitioners working on language-based solutions to contract-oriented software development. The workshop is partially funded by the Nordunet3 project “COSoDIS” (Contract-Oriented Software Development for Internet Services) and it attracted 25 participants. The program consists of 4 regular papers and 10 invited participant presentations