@techreport{8201, author = {{Heckel, Reiko and Ehrig, Hartmut and Wolter, Uwe and Corradini, Andrea}}, title = {{{Loose Semantics and Constraints for Graph Transformation Systems}}}, year = {{1997}}, } @inproceedings{8276, author = {{Gadducci, Fabio and Heckel, Reiko}}, booktitle = {{Proceedings of the Workshop on the General Theory of Graph Transformation Systems (GETGRATS 1997), Bordeaux (France)}}, title = {{{A 2-Categorical Presentation of Distributed Graph Transformation}}}, year = {{1997}}, } @inproceedings{8277, author = {{Gadducci, Fabio and Heckel, Reiko and Koch, Manuel}}, booktitle = {{Proceedings of the Workshop on the General Theory of Graph Transformation Systems (GETGRATS 1997), Bordeaux (France)}}, title = {{{Combining Graph Transformations with Temporal Logic}}}, year = {{1997}}, } @inproceedings{8278, author = {{Gadducci, Fabio and Heckel, Reiko}}, booktitle = {{Proceedings of the 12th International Workshop on Recent Trends in Algebraic Development Techniques (WADT 1997), Tarquinia (Italy)}}, pages = {{223--237}}, publisher = {{Springer}}, title = {{{An Inductive View of Graph Transformation}}}, volume = {{1376}}, year = {{1997}}, } @inproceedings{8279, author = {{Heckel, Reiko}}, booktitle = {{Proceedings of the Workshop on the General Theory of Graph Transformation Systems (GETGRATS 1997), Bordeaux (France)}}, title = {{{Compositional Development and Verification of Graph Transformation Systems Based on Views and View Integration}}}, year = {{1997}}, } @article{7402, author = {{Engels, Gregor and Jürgen Schneider, Hans}}, journal = {{International Journal on Software Engineering and Knowledge Engineering (IJSEKE)}}, number = {{4}}, pages = {{397--400}}, title = {{{Guest Editors' Introduction}}}, doi = {{http://dx.doi.org/10.1142/S0218194097000230}}, volume = {{7}}, year = {{1997}}, } @article{7403, abstract = {{The idea of a combined reference model- and view-based specification approach has been proposed recently in the software engineering community. In this paper we present a specification technique based on graph transformations which supports such a development approach. The use of graphs and graph transformations allows to satisfy the general requirements of an intuitive understanding and the integration of static and dynamic aspects on a well-defined and sound semantical base. On this background, formal notions of view and view relation are developed and the behaviour of views is described by a loose semantics. View relations are shown to preserve the behaviour of views. Moreover, we define a construction for the automatic integration of views which assumes that the dependencies between different views are described by a reference model. The views and the reference model are kept consistent manually, which is the task of a model manager. In case of more than two views more general scenarios are developed and discussed. We are able to show that the automatic view integration is compatible with the loose semantics, i.e., the behaviour of the system model is exactly the integration of the behaviours of the views. All concepts and results are illustrated at the well-known example of a banking system.}}, author = {{Engels, Gregor and Heckel, Reiko and Taentzer, Gabriele and Ehrig, Hartmut}}, journal = {{Int. Journal of Software and Knowledge Engeneering}}, number = {{4}}, pages = {{457--477}}, title = {{{A Combined Reference Model- and View-Based Approach to System Specification}}}, volume = {{7}}, year = {{1997}}, } @inbook{7515, abstract = {{The algebraic approaches to graph transformation are based on the concept of gluing of graphs corresponding to pushouts in suitable categories of graphs and graph morphisms. This allows one to give not only an explicit algebraic or set theoretical description of the constructions but also to use concepts and results from category theory in order to build up a rich theory and to give elegant proofs even in complex situations. In the previous chapter we have presented an overview of the basic notions and problems common to the two algebraic approaches the double pushout DPO approach and the single pushout SPO approach and their solutions in the DPO approach. In this chapter we introduce the SPO approach to graph transformation and some of its main results. We study application conditions for graph productions and the transformation of more general structures than graphs in the SPO approach where similar generalizations have been or could be studied also in the DPO approach. Finally we present a detailed comparison of the DPO and the SPO approach especially concerning the solutions to the problems discussed for both approaches in the previous chapter.}}, author = {{Ehrig, Hartmut and Heckel, Reiko and Korff, Martin and Löwe, Michael and Ribeiro, Leila and Wagner, Annika and Corradini, Andrea}}, booktitle = {{Handbook of Graph Grammars and Computing by Graph Transformations, Volume 1: Foundations}}, pages = {{247--312}}, publisher = {{World Scientific}}, title = {{{Algebraic Approaches to Graph Transformation, Part II: Single Pushout Approach and Comparison with Double Pushout Approach}}}, year = {{1997}}, } @inbook{7516, author = {{Engels, Gregor and Rekers, Jan and Andries, Marc}}, booktitle = {{Visual Language Theory}}, pages = {{241--255}}, publisher = {{Springer}}, title = {{{How to represent a visual specification}}}, year = {{1997}}, } @inbook{7517, abstract = {{The algebraic approaches to graph transformation are based on the concept of gluing of graphs, modelled by pushouts in suitable categories of graphs and graph morphisms. This allows one not only to give an explicit algebraic or set theoretical description of the constructions, but also to use concepts and results from category theory in order to build up a rich theory and to give elegant proofs even in complex situations. In this chapter we start with an overwiev of the basic notions common to the two algebraic approaches, the double-pushout (DPO) approach and the singlepushout (SPO) approach; next we present the classical theory and some recent development of the double-pushout approach. The next chapter is devoted instead to the single-pushout approach, and it is closed by a comparison between the two approaches.}}, author = {{Corradini, Andrea and Montanari, Ugo and Rossi, Francesca and Ehrig, Hartmut and Heckel, Reiko and Löwe, Michael}}, booktitle = {{Handbook of Graph Grammars and Computing by Graph Transformation, Volume 1: Foundations}}, pages = {{163--245}}, publisher = {{World Scientific}}, title = {{{Algebraic Approaches to Graph Transformation, Part I: Basic Concepts and Double Pushout Approach}}}, year = {{1997}}, } @proceedings{7796, editor = {{Engels, Gregor and Ehrig, Hartmut and Rozenberg, Grzegorz and Skowron, Andrzej}}, number = {{3-4}}, publisher = {{IOS Press}}, title = {{{Special Issue on Graph Transformations}}}, volume = {{26}}, year = {{1996}}, } @inproceedings{7834, abstract = {{The concept of views is used on two levels. First, so-called design views are developed for structuring specifications, that is, a system is modeled according to different views (e.g., representing the needs of different kinds of users) which have to be synchronized afterwards in order to build the whole system. Views can be specified by means of typed graph transformation systems, where the type graph determines the visible types and the productions describe the known operations of that view. The synchronization of views is done by the construction of cooperative parallel composition of graph transformation systems, developed by Leila Ribeiro and presented at the same seminar. If the specification is complete, a view may describe an observation of the system in operation. In this case we speak of a user view. It turns out that the semantics of such a view cannot be described by computations (i.e., graph transformations), but just by observations of computations of the global system. Such observations of computations cannot be represented by graph transformations in the usual sense because a local view may lack operations (productions) of the global system, so that state changes may be observed that do not have a cause in the local view. Therefore, the notion of graph transition is introduced as loose semantics for productions, where the production specifies only a lower bound to the activities that are to happen during application. Contrastingly, in the classical doublepushout approach to graph rewriting, productions are interpreted as complete descriptions of the transformations to be performed. For typed graph transformation systems a transition sequence semantics is developed, comprising all finite and infinite sequences of transitions in a system. Moreover, this semantics is shown to be compositional w.r.t. the synchronization of views.}}, author = {{Ehrig, Hartmut and Heckel, Reiko and Padberg, Julia and Taentzer, Gabriele and Wolter, Uwe and Corradini, Andrea and Engels, Gregor}}, booktitle = {{Report on the Dagstuhl-Seminar 9637 on Graph Transformations in Computer Science}}, number = {{155}}, pages = {{11--12}}, publisher = {{Technical University of Berlin}}, title = {{{Synchronization of Views and Loose Semantics of Typed Graph Productions}}}, year = {{1996}}, } @inproceedings{7835, author = {{Heckel, Reiko}}, booktitle = {{Report on the Dagstuhl-Seminar 9637 on Graph Transformations in Computer Science}}, number = {{155}}, pages = {{12--13}}, publisher = {{Technical University of Berlin}}, title = {{{Behavioral Constraints for Loose Graph Transformation Systems}}}, year = {{1996}}, } @inproceedings{7836, abstract = {{A large industrial process, software maintenance, has been modelled by using the process modelling language SOCCA. The paper reports about the experiences with this trial. In particular, feasibility, expressiveness, quality and the overall benefits of a formal SOCCA model are discussed and compared to the formerly existing informal process description. In order to illustrate the results, a well chosen process model fragment from the larger model is outlined in detail. It addresses in particular the human-intensive cooperation within the process and shows the seamless combination of technical components and human agent components in the SOCCA model. The main conclusions from this trial are that formal SOCCA models are suited to model realistic industrial processes and that due to an intrinsic modular structure of a SOCCA model, even huge models remain reasonably readable and understandable}}, author = {{de Bunje, Tineke and Engels, Gregor and Groenewegen, Luuk and Matsinger, Aart and Rijnbeek, Martin}}, booktitle = {{Proceedings of the Fourth International Conference on the Software Process (ICSP 1996), Brighton (UK)}}, pages = {{13--26}}, publisher = {{IEEE Computer Society}}, title = {{{Industrial maintenance modelled in SOCCA: an experience report}}}, doi = {{http://dx.doi.org/10.1109/ICSP.1996.565021}}, year = {{1996}}, } @inproceedings{7837, abstract = {{In order to manage the complexity of large system specifications, they have to be decomposed into subspecifications. Each subspecification describes a certain part of the system. This might be a certain aspect, like the data, dynamic, or functional aspect, as it is known from object-oriented modelling techniques. Or it might be a certain view onto the system, as it is known from database modelling techniques. The talk motivates the usage of views in graph grammarbased specifications. First, the usage of typed graph grammars inherently ensures an integration of the data and the functional aspect within a view. Second, it is explained that it is not appropriate in case of views to have a fixed semantics. The standard fixed semantics, i.e. a graph transformation system, has to be relaxed to a loose semantics, i.e. a graph transition system. This reflects the idea that a view models only a part of the complete system. Other views may overlap a view with respect to data or functionality. A complete system specification is yielded by exploiting the approach of cooperative parallel composition of graph grammars (see talk by Leila Ribeiro).}}, author = {{Engels, Gregor and Ehrig, Hartmut and Heckel, Reiko and Taentzer, Gabriele and Corradini, Andrea}}, booktitle = {{Report on Dagstuhl-Seminar 9637 on Graph Transformations in Computer Science}}, pages = {{11}}, publisher = {{Technical University of Berlin}}, title = {{{A View-Based Approach to System Modelling}}}, volume = {{155}}, year = {{1996}}, } @inproceedings{7838, abstract = {{Object-oriented specification mechanisms have become famous for modelling structure and behaviour together in terms of autonomous objects communicating via message passing. However, whereas most object-oriented specification methods are strong in modelling the local behaviour of single objects, they fall short on modelling the coordinated behaviour and collaboration of several objects together The aim of this paper is to contribute to fill this gap. The paper reports on concepts, language constructs, and experiences with three collaboration formalisms in the area of object-oriented specifications.}}, author = {{Engels, Gregor and Groenewegen, Luuk and Kappel, Gerti}}, booktitle = {{Proceedings of IFIP World Conference on IT Tools (1996), Canberra (Australia)}}, pages = {{437--452}}, publisher = {{Chapman & Hall}}, title = {{{Object-oriented specification of coordinated collaboration}}}, year = {{1996}}, } @techreport{8197, abstract = {{The framework of graph transformation combines the potentials and advantages of both, graphs and rules, into a single computational paradigm. In this paper we survey recent developments in applying graph transformation as a rule-based framework for the specification and development of systems, languages, and tools. After presenting the basic features of graph transformation, we discuss a spectrum of applications including the evaluation of functional expressions, the specification of an interactive graphical tool, an example specification for abstract data types, and the definition of a visual database query language. The case studies indicate the need for a graph transformation language that provides suitable structuring principles and is independent of a particular graph transformation approach. To this end, we sketch the basic features of the new graph- and rule-centered language Grace, currently under development, that permits systematic and structured specification and programming based on graph transformation.}}, author = {{Andries, Marc and Engels, Gregor and Habel, Annegret and Hoffmann, Berthold and Kreowski, Hans-Jörg and Kuske, Sabine and Plump, Detlef and Schürr, Andy and Taentzer, Gabriele}}, publisher = {{University of Bremen, Department of Mathematics and Computer Science}}, title = {{{Graph Transformation for Specification and Programming}}}, year = {{1996}}, } @techreport{8198, author = {{Busatto, Giorgio and Engels, Gregor}}, publisher = {{Vakgroep Informatica, Rijksuniversiteit Leiden}}, title = {{{Definition of an Encapsulated Hierarchical Graph Data Model: Static Aspects, Part 1.}}}, year = {{1996}}, } @techreport{8199, author = {{Engels, Gregor and Groenewegen, Luuk and Kappel, Gerti}}, publisher = {{Vakgroep Informatica, Rijksuniversiteit Leiden}}, title = {{{Object-oriented Specification of Coordinated Collaboration}}}, year = {{1996}}, } @techreport{8200, author = {{Heckel, Reiko and Corradini, Andrea and Ehrig, Hartmut and Löwe, Michael}}, title = {{{Horizontal and Vertical Structuring of Typed Graph Transformation Systems}}}, year = {{1996}}, }