Forward Analysis and Model Checking for Trace Bounded WSTS

We investigate a subclass of well-structured transition systems (WSTS), the bounded---in the sense of Ginsburg and Spanier (Trans. AMS 1964)---complete deterministic ones, which we claim provide an adequate basis for the study of forward analyses as developed by Finkel and Goubault-Larrecq (Logic. Meth. Comput. Sci. 2012). Indeed, we prove that, unlike other conditions considered previously for the termination of forward analysis, boundedness is decidable. Boundedness turns out to be a valuable restriction for WSTS verification, as we show that it further allows to decide all $\omega$-regular properties on the set of infinite traces of the system

On Languages Accepted by P/T Systems Composed of joins

Recently, some studies linked the computational power of abstract computing systems based on multiset rewriting to models of Petri nets and the computation power of these nets to their topology. In turn, the computational power of these abstract computing devices can be understood by just looking at their topology, that is, information flow. Here we continue this line of research introducing J languages and proving that they can be accepted by place/transition systems whose underlying net is composed only of joins. Moreover, we investigate how J languages relate to other families of formal languages. In particular, we show that every J language can be accepted by a log n space-bounded non-deterministic Turing machine with a one-way read-only input. We also show that every J language has a semilinear Parikh map and that J languages and context-free languages (CFLs) are incomparable

Context sensitive user interfaces

This paper presents a conceptual design model for user interfaces (MASS1) and a general formalism for dialogue specification (Interaction Scripts) which are the most important components of an approach to the methodological, iterative design of Interactive Systems from formal, model-based specification of both the application and the User Interface (UI). This approach allows the integration of both dialogue and application semantics from the beginning of the design process, by using prototypes derived from both specifications. Assuming that all the application semantics is available at early design stages, the MASS model defines a set of guidelines that will enforce the designer to create user interfaces that will present a prophylactic instead of the usual therapeutic behaviour. By a prophylactic behaviour it is meant, metaphorically, that the UI will exhibit a behaviour that prevents and avoids both syntactic and semantic user errors, in contrast with the most usual therapeutic, or error recovery, behaviour. The dialogue specification formalism(Interaction Scripts) despite being general, in the sense that it may be applied to the specification of any kind of dialogue, is specially suited to the specification of UIs with the behaviour prescribed by the MASS design model. In addition, it is independent from concrete environment details, therefore allowing for different implementations of the same specification, that is, different looks and feels. The operational semantics of the Interaction Script notation is also presented in terms of Petri-Nets that are automatically generated from the Interaction Script specification of the dialogue controller

Max-plus algebra in the history of discrete event systems

This paper is a survey of the history of max-plus algebra and its role in the field of discrete event systems during the last three decades. It is based on the perspective of the authors but it covers a large variety of topics, where max-plus algebra plays a key role

Translating Asynchronous Games for Distributed Synthesis (Full Version)

In distributed synthesis, we generate a set of process implementations that, together, accomplish an objective against all possible behaviors of the environment. A lot of recent work has focussed on systems with causal memory, i.e., sets of asynchronous processes that exchange their causal histories upon synchronization. Decidability results for this problem have been stated either in terms of control games, which extend Zielonka's asynchronous automata by partitioning the actions into controllable and uncontrollable, or in terms of Petri games, which extend Petri nets by partitioning the tokens into system and environment players. The precise connection between these two models was so far, however, an open question. In this paper, we provide the first formal connection between control games and Petri games. We establish the equivalence of the two game models based on weak bisimulations between their strategies. For both directions, we show that a game of one type can be translated into an equivalent game of the other type. We provide exponential upper and lower bounds for the translations. Our translations make it possible to transfer and combine decidability results between the two types of games. Exemplarily, we translate decidability in acyclic communication architectures, originally obtained for control games, to Petri games, and decidability in single-process systems, originally obtained for Petri games, to control games

String Diagrammatic Trace Theory

We extend the theory of formal languages in monoidal categories to the multi-sorted, symmetric case, and show how this theory permits a graphical treatment of topics in concurrency. In particular, we show that Mazurkiewicz trace languages are precisely symmetric monoidal languages over monoidal distributed alphabets. We introduce symmetric monoidal automata, which define the class of regular symmetric monoidal languages. Furthermore, we prove that Zielonka's asynchronous automata coincide with symmetric monoidal automata over monoidal distributed alphabets. Finally, we apply the string diagrams for symmetric premonoidal categories to derive serializations of traces.Comment: Paper accepted for MFCS 202