Abstract. Insight in the global structure of a state space is of great help in the analysis of the underlying process. We advocate the use of visualization for this purpose and present a new method to visualize the structure of very large state spaces. The method uses a clustering method to obtain a simplified representation, which is used as a backbone for the display of the entire state space. With this visualization we are able to answer questions about the global structure of a state space that cannot easily be answered by conventional methods. We show this by presenting a number of visualizations of real-world protocols. 1

Abstract. Parking garages that stow and retrieve cars automatically are becoming viable solutions for parking shortages. However, these are complex systems and a number of severe incidents involving such garages have been reported. Many of these are related to safety issues in software. We apply verification techniques to develop a software design for an automated parking garage. This design meets a number of safety requirements. We provide a software architecture that allows one to split implementation, safety and algorithmic aspects of the software. Consequently, we give a high-level description of the safety aspects and verify a number of safety requirements on this model. Also, we briefly discuss how this analysis is simplified by using a custom visualization tool. 1

Finite state machines (FSM) are a basic component in hardware design, they represent the transformation between inputs and outputs for sequential designs. FSMs can be represented graphically, which would help the designer to visualize and design in a more efficient way, on the other hand the designer requires a fast direct way to convert the visualized design to hardware description languages (HDL) code directly in order to simulate and implement it for synthesis and analysis. In this paper, we present a tool which starting from a graphical FSM representation, produces a behavioral HDL code which can be directly analyzed and synthesized.

Data about movement through a space is increasingly becoming available for capture and analysis. In many applications, this data is captured or modeled as transitions between a small number of areas of interests, or a finite set of states, and these transitions constitute paths in the space. Similarities and differences between paths are of great importance to such analyses, but can be difficult to assess. In this work we present a visualization approach for representing paths in context, where individual paths can be compared to other paths or to a group of paths. Our approach summarizes path behavior using a simple circular layout, including information about state and transition likelihood using Markov random models, together with information about specific path and state behavior. The layout avoids line crossovers entirely, making it easy to observe patterns while reducing visual clutter. In our tool, paths can either be compared in their natural sequence or by aligning multiple paths using Multiple Sequence Alignment, which can better highlight path similarities. We applied our technique to eye tracking data and cell phone tower data used to capture human movement.

We describe the toolset for the behavioural specification language mCRL2. The purpose of the toolset is to analyse abstract models that describe the communication behaviour of software based systems. With the help of the toolset we want to efficiently detect and prevent problems in software, preferably before it is built. The tools allow to transform specifications, generate and visualise state spaces, verify modal properties, and much more. In order to facilitate reuse of the code most of the functionality is included in libraries. This makes the toolset suitable as a platform for third party tool development and for other specification languages as well. The toolset is distributed under the Boost license, which permits such use.