@inproceedings{8260,
  abstract     = {{This experience report describes the development of the CASE environment CADDY Computer-Aided Design of non-traditional Databases 1 which oflers an integrated set of tools for specifying, analyzing, and prototyping a database application on a conceptual level. This environment was designed and implemented during the last four years at Braunschweig Technical University (Germany). The process of developing this environment consisted of a sequence of development steps, where each step corresponded to (at least) one of five main tasks. The intention of this report is to describe these five tasks. At the end, we will critically reflect on the achieved results and solved problems, but also on still open questions of the CADDY environment.}},
  author       = {{Engels, Gregor and Löhr-Richter, Perdita}},
  booktitle    = {{Proceedings of the Fifth International Workshop on Computer-Aided Software Engineering (CASE 1992), Montreal (Canada)}},
  pages        = {{19--22}},
  publisher    = {{IEEE Computer Society}},
  title        = {{{CADDY: A Highly Integrated Environment to Support Conceptual Database Design}}},
  year         = {{1992}},
}

@inproceedings{8261,
  author       = {{Engels, Gregor and Groenewegen, Luuk}},
  booktitle    = {{Proceedings of the Second European Workshop on Software Process Technology (EWSPT 92), Trondheim, Norway}},
  pages        = {{58--60}},
  publisher    = {{Springer}},
  title        = {{{Specification of Coordinated Behaviour in the Software Development Process}}},
  doi          = {{http://dx.doi.org/10.1007/BFb0017495}},
  volume       = {{635}},
  year         = {{1992}},
}

@article{7408,
  abstract     = {{This paper presents the high-level query language SQL/EER for an extended Entity-Relationship model (EER model). SQL/EER directly supports all the concepts of the EER model and takes into account well-known features that are integral part of contemporary query languages, e.g. arithmetic and aggregate functions. In contrast to usual descriptions of query languages, we give SQL/EER a complete formal specification of syntax and sematics. This syntax is defined by using an attribute grammar which fixes the context-free structure and the context-sensitive rules. The operational semantics is defined by formally translating SQL/EER queries into queries of an existing, semantically well-defined calculus. The attribute grammar is extended to cover this translation, too. The query language SQL/EER is used in a database design environment. In this context, the formal specification of its syntax and the semantics has been used to implement a syntax-directed editor and a query interpreter for SQL/EER.}},
  author       = {{Hohenstein, Uwe and Engels, Gregor}},
  journal      = {{Information Systems}},
  number       = {{3}},
  pages        = {{209--242}},
  title        = {{{SQL/EER - Syntax and Semantics of an Entity-Relationship-Based Query Language}}},
  doi          = {{http://dx.doi.org/10.1016/0306-4379(92)90014-E}},
  volume       = {{17}},
  year         = {{1992}},
}

@article{7409,
  abstract     = {{The conceptual modeling approach of the IPSEN (Integrated Project Support Environment) project for building highly integrated environments is based on using attributed graphs to model and implement arbitrary object structures, in particular all kinds of software documents and their relationships. A language based on graph grammars, called PROGRESS (Programmed Graph REwriting SyStems), and a suitable method for the application of this language, called graph grammar engineering, have been developed over the last ten years. This language and method are being extensively used for specifying the complex graph structures of internal document representations as well as for specifying the functionality of all tools (editors, browsers, analyzers, debuggers) working on these internal representations. This paper explains the language and the method for applying the language based on a pragmatic nontrivial example of a software production process and its corresponding documents. In particular, it is shown why and how a graph grammar-based strongly typed language is perfectly suitable to formally specify highly integrated software tools. In addition, it is shown that the implementation of these tools (i.e., an environment composed of these tools) is systematically being derived from the formal specifications.}},
  author       = {{Engels, Gregor and Lewerentz, Claus and Nagl, Manfred and Schäfer, Wilhelm and Schürr, Andy}},
  journal      = {{ACM Transactions on Software Engineering and Methodology (TOSEM)}},
  number       = {{2}},
  pages        = {{135--167}},
  title        = {{{Building Integrated Software Development Environments, Part I: Tool Specification}}},
  volume       = {{1}},
  year         = {{1992}},
}

@article{7410,
  abstract     = {{In this paper, we motivate and present a data model for conceptual design of structural and behavioural aspects of databases. We follow an object centered design paradigm in the spirit of semantic data models. The specification of structural aspects is divided into modelling of object structures and modelling of data types used for describing object properties. The specification of object structures is based on an Extended Entity--Relationship (EER) model. The specification of behavioural aspects is divided into the modelling of admissible database state evolutions by means of temporal integrity constraints and the formulation of database (trans)actions. The central link for integrating these design components is a descriptive logic--based query language for the EER model. The logic part of this language is the basis for static constraints and descriptive action specifications by means of pre- and postconditions. A temporal extension of this logic is the specification language for temporal integrity constraints. We emphasize that the various aspects of a database application are specified using several appropriate, but yet compatible formalisms, which are integrated by a unifying common semantic.}},
  author       = {{Engels, Gregor and Gogolla, Martin and Hohenstein, Uwe and Hülsmann, Klaus and Löhr-Richter, Perdita and Saake, Gunter and Ehrich, Hans-Dietrich}},
  journal      = {{Data & Knowledge Engineering}},
  number       = {{2}},
  pages        = {{157--204}},
  title        = {{{Conceptual Modelling of Database Applications Using an Extended ER Model}}},
  doi          = {{http://dx.doi.org/10.1016/0169-023X(92)90008-Y}},
  volume       = {{9}},
  year         = {{1992}},
}

@techreport{8188,
  author       = {{Löhr-Richter, Perdita and Engels, Gregor}},
  publisher    = {{Leiden University}},
  title        = {{{Incremental Design of Conceptual Database Schemata with CADDY}}},
  year         = {{1991}},
}

@inproceedings{7824,
  author       = {{Hohenstein, Uwe and Engels, Gregor}},
  booktitle    = {{Proceedings of the 9th International Conference on Entity-Relationship Approach (ER 90), Lausanne, Switzerland}},
  pages        = {{177--188}},
  publisher    = {{ER Institute}},
  title        = {{{Formal Semantics of an Entity-Relationship Query Language}}},
  year         = {{1990}},
}

@inproceedings{8259,
  abstract     = {{Semantic data models have been widely studied for the conceptual specification of databases. However, most of these data models are restricted to the description of the static structure of a database. They do not provide means to specify the dynamic behaviour of a database. This paper sketches a language for the specification of actions on databases which have been specified by an Extended Entity-Relationship (EER) schema. These actions are based on so-called elementary actions, which are automatically be derived from the EER schema. So, it can always be guaranteed that these schema dependent elementary actions preserve all inherent integrity constraints. The semantics of the elementary actions is given in two steps: First, it is shown how the semantics of a database schema, i.e., a current database state, can be represented by an attributed graph. Then, the semantics of elementary actions is given by programmed graph replacements.}},
  author       = {{Engels, Gregor}},
  booktitle    = {{Proceedings of the workshop on Graph Grammars and Their Application to Computer Science (1990), Bremen (Germany)}},
  pages        = {{344--362}},
  publisher    = {{Springer}},
  title        = {{{Elementary Actions on an Extended Entity-Relationship Database}}},
  doi          = {{http://dx.doi.org/10.1007/BFb0017372}},
  volume       = {{532}},
  year         = {{1990}},
}

@inproceedings{7821,
  author       = {{Ebert, Jürgen and Engels, Gregor}},
  booktitle    = {{Software-Entwicklung: Konzepte, Erfahrungen, Perspektiven, Fachtagung, 1989, Marburg (Germany)}},
  pages        = {{238--250}},
  publisher    = {{Springer}},
  title        = {{{Konzepte einer Software-Architektur-Beschreibungssprache}}},
  volume       = {{212}},
  year         = {{1989}},
}

@inproceedings{7822,
  author       = {{Engels, Gregor}},
  booktitle    = {{Tagungsband GI-Fachtagung "Interaktive Schnittstellen für Informationssysteme", TU Clausthal, Notizen zu Interaktive Systeme}},
  pages        = {{1--16}},
  title        = {{{CADDY-O: Syntaxgestütztes, graphisches Entwerfen konzeptioneller Datenbankschemata}}},
  volume       = {{18}},
  year         = {{1989}},
}

@inproceedings{7823,
  author       = {{Engels, Gregor and Hohenstein, Uwe and Hülsmann, Klaus and Löhr-Richter, Perdita and Ehrich, Hans-Dietrich}},
  booktitle    = {{Proceedings of the International Conference on System Development Environments & Factories, Berlin, Germany}},
  publisher    = {{Pitman Publishing}},
  title        = {{{CADDY: Computer-Aided Design of Non-Standard Databases}}},
  year         = {{1989}},
}

@techreport{8187,
  author       = {{Engels, Gregor}},
  publisher    = {{TU Braunschweig}},
  title        = {{{Benutzerschnittstelle und Architektur der integrierten Datenbankentwurfsumgebung CADDY (Kurzfassung)}}},
  year         = {{1989}},
}

@book{7511,
  author       = {{Engels, Gregor and Schäfer, Wilhelm}},
  publisher    = {{Teubner}},
  title        = {{{Programmentwicklungsumgebungen: Konzepte und Realisierung}}},
  year         = {{1989}},
}

@inproceedings{7818,
  abstract     = {{This paper describes the design of the integrated user interface of the software development environment IPSEN (Integrated Programming Support Environment). We explain the characteristic features of the IPSEN user interface, namely the structured layout of the screen, the command-driven tool activation, and especially the highly integrated use of the IPSEN tool set. We demonstrate those features by taking a sample set of tools of the IPSEN environment. That tool set supports all the programming-in-the-small activities within IPSEN. Finally, we sketch the realization of two prototypes running on an IBM-AT and a net of SUN workstations.}},
  author       = {{Engels, Gregor and Janning, Thorsten and Schäfer, Wilhelm}},
  booktitle    = {{Proceedings of the conference on ACM SIGSMALL/PC symposium on ACTES (SIGSMALL 1988), Cannes (France)}},
  pages        = {{1--10}},
  publisher    = {{ACM Press}},
  title        = {{{A Highly Integrated Tool Set for Program Development Support}}},
  doi          = {{http://dx.doi.org/10.1145/62453.62454}},
  year         = {{1988}},
}

@inproceedings{7819,
  author       = {{Engels, Gregor and Hohenstein, Uwe and Neugebauer, Leonore and Saake, Gunter and Ehrich, Hans-Dietrich}},
  booktitle    = {{Proceedings of DBTA/SI Data Dictionaries und Entwicklungswerkzeuge für Datenbank-Anwendungen, Zürich, Switzerland}},
  pages        = {{151--157}},
  publisher    = {{Verlag der Fachvereine an den Schweiz. Hochschulen und Techniken}},
  title        = {{{Konzeption einer integrierten Datenbank-Entwurfsumgebung}}},
  year         = {{1988}},
}

@inproceedings{7820,
  author       = {{Engels, Gregor and Hohenstein, Uwe and Saake, Gunter and Ehrich, Hans-Dietrich}},
  booktitle    = {{Proceedings of the GI-Workshop on "Sprachspezifische Programmierumgebungen"}},
  editor       = {{Engels, Gregor and Hohenstein, Uwe and Saake, Gunter and Ehrich, Hans-D.}},
  pages        = {{38--51}},
  publisher    = {{G. Snelting}},
  title        = {{{Auf dem Weg zu einer integrierten Datenbank-Entwurfsumgebung}}},
  year         = {{1988}},
}

@techreport{8186,
  author       = {{Ebert, Jürgen and Engels, Gregor}},
  publisher    = {{EWH Koblenz}},
  title        = {{{Ein Konzept zur Beschreibung von Software-Architekturen}}},
  year         = {{1988}},
}

@inproceedings{8258,
  author       = {{Engels, Gregor and Janning, Thorsten and Schäfer, Wilhelm}},
  booktitle    = {{Proceedings of GI-Workshop Sprachspezifische Programmierumgebungen, Darmstadt, Germany}},
  title        = {{{Die Benutzerschnittstelle einer integrierten Modula-2 Programmentwicklungsumgebung}}},
  year         = {{1988}},
}

@inproceedings{7816,
  abstract     = {{This paper describes the realization of an execution tool for Modula-2 modules which is part of an integrated tool set in a software development environment termed IPSEN (Incremental Programming Support Environment). In this environment, all software documents, e.g. Modula-2 modules, are manipulated by syntax-directed editors and are represented internally by attributed graphs. The execution of Modula-2 modules is done by two cooperating interpreters. The first one is a graph interpreter which traverses the internal graph from statement to statement. These statements are translated into a low-level, more efficiently executable object code and interpreted by a second interpreter. This concept of a hybrid interpreter allows the realization of an execution tool which offers a lot of runtime support features to the user.}},
  author       = {{Engels, Gregor and Schürr, Andy}},
  booktitle    = {{Proceedings of the 1st European Software Engineering Conference (ESEC '87), Strasbourg (France)}},
  pages        = {{80--88}},
  publisher    = {{Springer}},
  title        = {{{A Hybrid Interpreter in a Software Development Environment}}},
  volume       = {{289}},
  year         = {{1987}},
}

@inproceedings{7817,
  author       = {{Engels, Gregor and Nagl, Manfred and Schäfer, Wilhelm}},
  booktitle    = {{Proceedings of the ACM SIGSOFT/SIGPLAN Software Engineering Symposium on Practical Software Development Environments, Palo Alto, USA}},
  number       = {{1}},
  pages        = {{190--198}},
  publisher    = {{ACM SIGPLAN Notices}},
  title        = {{{On the Structure of Structure-Oriented Editors for Different Applications}}},
  volume       = {{22}},
  year         = {{1987}},
}