Resource-Bound Quantification for Graph Transformation

Graph transformation has been used to model concurrent systems in software engineering, as well as in biochemistry and life sciences. The application of a transformation rule can be characterised algebraically as construction of a double-pushout (DPO) diagram in the category of graphs. We show how intuitionistic linear logic can be extended with resource-bound quantification, allowing for an implicit handling of the DPO conditions, and how resource logic can be used to reason about graph transformation systems

Primitives for Contract-based Synchronization

We investigate how contracts can be used to regulate the interaction between processes. To do that, we study a variant of the concurrent constraints calculus presented in [1], featuring primitives for multi-party synchronization via contracts. We proceed in two directions. First, we exploit our primitives to model some contract-based interactions. Then, we discuss how several models for concurrency can be expressed through our primitives. In particular, we encode the pi-calculus and graph rewriting.Comment: In Proceedings ICE 2010, arXiv:1010.530

A case study : verifying a mutual exclusion protocol with process creation using graph transformation systems

We verify a mutual exclusion protocol with dynamic process creation based on token passing. The protocol is specified using object-based graph grammars. We introduce the protocol and show how the mutual exclusion property and other properties can be verified using the tool Augur, a verification tool for graph transformation systems based on an approximated unfolding technique

A General Framework for Well-Structured Graph Transformation Systems

Graph transformation systems (GTSs) can be seen as wellstructured transition systems (WSTSs), thus obtaining decidability results for certain classes of GTSs. In earlier work it was shown that wellstructuredness can be obtained using the minor ordering as a well-quasiorder. In this paper we extend this idea to obtain a general framework in which several types of GTSs can be seen as (restricted) WSTSs. We instantiate this framework with the subgraph ordering and the induced subgraph ordering and apply it to analyse a simple access rights management system.Comment: Extended version (including proofs) of a paper accepted at CONCUR 201

Logic and Automata

Mathematical logic and automata theory are two scientific disciplines with a fundamentally close relationship. The authors of Logic and Automata take the occasion of the sixtieth birthday of Wolfgang Thomas to present a tour d'horizon of automata theory and logic. The twenty papers in this volume cover many different facets of logic and automata theory, emphasizing the connections to other disciplines such as games, algorithms, and semigroup theory, as well as discussing current challenges in the field

User support for software development technologies

The adoption of software development technologies is very closely related to the topic of user support. This is especially true in early phases, when the users are not familiar with the modification or the build processes of the software that has to be developed nor with the technology used for software development. This work introduces an approach to improve the usability of software development technologies represented by the Combinatory Logic Synthesizer (CL)S Framework. (CL)S is based on a type inhabitation algorithm for the combinatory logic with intersection types and aims to automatically create software components from a domain-specified repository. The framework yields a complete enumeration of all inhabitants. The inhabitation results are computed in the form of tree grammars. Unfortunately, the underlying type system allows limited application of domain-specific knowledge. To compensate for this limit, this work provides a framework for debugging intersection type specifications and filtering inhabitation results using domain-specific constraints as main aspects. The aim of the debugger is to make potentially incomplete or erroneous input specifications and decisions of the inhabitation algorithm understandable for those who are not experts in the field of type theory. The combination of tree grammars and graph theory forms the foundation of a clear representation of the computed results that informs users about the search process of the algorithm. The graphical representations are based on hypergraphs that illustrate the inhabitation in a step-wise fashion. Within the scope of this work, three filtering algorithms were implemented and investigated. The filtering algorithm integrated into the framework for user support and used for the restriction of inhabitation results is practically feasible and represents a clear improvement compared to existing approaches. It is based on modifying the tree grammars resulting from the (CL)S Framework. Additionally, the usability of the (CL)S Framework is supported by eight perspectives included in a web-based integrated development environment (IDE) that provides detailed graphical and textual information about the synthesis

Bigraphs and Their Algebra

AbstractBigraphs are a framework in which both existing process calculi and new models of behaviour can be formulated, yielding theory that is shared among these models. A short survey of the main features of bigraphs is presented, showing how they can be developed from standard graph theory using elementary category theory. The algebraic manipulation of bigraphs is outlined with the help of illustrations. The treatment of dynamics is then summarised. Finally, origins and some related work are discussed. The paper provides a motivating introduction to bigraphs

Formalizing graphical notations

The thesis describes research into graphical notations for software engineering, with a principal interest in ways of formalizing them. The research seeks to provide a theoretical basis that will help in designing both notations and the software tools that process them. The work starts from a survey of literature on notation, followed by a review of techniques for formal description and for computational handling of notations. The survey concentrates on collecting views of the benefits and the problems attending notation use in software development; the review covers picture description languages, grammars and tools such as generic editors and visual programming environments. The main problem of notation is found to be a lack of any coherent, rigorous description methods. The current approaches to this problem are analysed as lacking in consensus on syntax specification and also lacking a clear focus on a defined concept of notated expression. To address these deficiencies, the thesis embarks upon an exploration of serniotic, linguistic and logical theory; this culminates in a proposed formalization of serniosis in notations, using categorial model theory as a mathematical foundation. An argument about the structure of sign systems leads to an analysis of notation into a layered system of tractable theories, spanning the gap between expressive pictorial medium and subject domain. This notion of 'tectonic' theory aims to treat both diagrams and formulae together. The research gives details of how syntactic structure can be sketched in a mathematical sense, with examples applying to software development diagrams, offering a new solution to the problem of notation specification. Based on these methods, the thesis discusses directions for resolving the harder problems of supporting notation design, processing and computer-aided generic editing. A number of future research areas are thereby opened up. For practical trial of the ideas, the work proceeds to the development and partial implementation of a system to aid the design of notations and editors. Finally the thesis is evaluated as a contribution to theory in an area which has not attracted a standard approach