Presentation of the 9th Edition of the Model Checking Contest.

International audience; The Model Checking Contest (MCC) is an annual competition of software tools for model checking. Tools must process an increasing benchmark gathered from the whole community and may participate in various examinations: state space generation, computation of global properties, computation of some upper bounds in the model, evaluation of reachability formulas, evaluation of CTL formulas, and evaluation of LTL formulas.For each examination and each model instance, participating tools are provided with up to 3600 s and 16 gigabyte of memory. Then, tool answers are analyzed and confronted to the results produced by other competing tools to detect diverging answers (which are quite rare at this stage of the competition, and lead to penalties).For each examination, golden, silver, and bronze medals are attributed to the three best tools. CPU usage and memory consumption are reported, which is also valuable information for tool developers

Parameterized Reachability Graph for Software Model Checking Based on PDNet

Model checking is a software automation verification technique. However, the complex execution process of concurrent software systems and the exhaustive search of state space make the model-checking technique limited by the state-explosion problem in real applications. Due to the uncertain input information (called system parameterization) in concurrent software systems, the state-explosion problem in model checking is exacerbated. To address the problem that reachability graphs of Petri net are difficult to construct and cannot be explored exhaustively due to system parameterization, this paper introduces parameterized variables into the program dependence net (a concurrent program model). Then, it proposes a parameterized reachability graph generation algorithm, including decision algorithms for verifying the properties. We implement LTL-x verification based on parameterized reachability graphs and solve the problem of difficulty constructing reachability graphs caused by uncertain inputs

Analysing Coloured Petri Nets by the Occurrence Graph Method

This paper provides an overview og the work done for the author's PhD thesis. The research area of Coloured Petri Nets is introduced, and the available analysis methods are presented. The occurrence graph method, which is the main subject of this thesis, is described in more detail. Summaries of the six papers which, together with this overview, comprise the thesis are given, and the contributions are discussed.A large portion of this overview is dedicated to a description of related work. The aim is twofold: First, to survey pertinent results within the research areas of -- in increasing generality -- Coloured Petri Nets, High-level Petri Nets, and formalisms for modelling and analysis of parallel and distributed systems. Second, to put the results obtained in this thesis in a wider perspective by comparing them with important related work

Improving explicit model checking for Petri nets

Model checking is the automated verification that systematically checks if a given behavioral property holds for a given model of a system. We use Petri nets and temporal logic as formalisms to describe a system and its behavior in a mathematically precise and unambiguous manner. The contributions of this thesis are concerned with the improvement of model checking efficiency both in theory and in practice. We present two new reduction techniques and several supplementary strength reduction techniques. The thesis also enhances partial order reduction for certain temporal logic classes

Parallel computation of the reachability graph of petri net models with semantic information

Formal verification plays a crucial role when dealing with correctness of systems. In a previous work, the authors proposed a class of models, the Unary Resource Description Framework Petri Nets (U-RDF-PN), which integrated Petri nets and (RDF-based) semantic information. The work also proposed a model checking approach for the analysis of system behavioural properties that made use of the net reachability graph. Computing such a graph, specially when dealing with high-level structures as RDF graphs, is a very expensive task that must be considered. This paper describes the development of a parallel solution for the computation of the reachability graph of U-RDF-PN models. Besides that, the paper presents some experimental results when the tool was deployed in cluster and cloud frameworks. The results not only show the improvement in the total time required for computing the graph, but also the high scalability of the solution, which make it very useful thanks to the current (and future) availability of cloud infrastructures