. This paper gives a cohesive approach to modeling and implementation with graphs. This approach uses extended entity relationship #EER# diagrams supplemented with the Z-like constraint language GRAL. Due to the foundation of EER#GRAL on Z a common formal basis exists. EER#GRAL descriptions give conceptual models which can be implemented in a seamless manner by e#cient data structures using the GraLab graph library. Descriptions of four medium size EER#GRAL-applications conclude the paper to demonstrate the usefulness of the approach in practice. 1 Introduction Using graphs as a means for discussing problems, as a medium for formal reasoning, or as a paradigm for data structures in software is folklore in today's computer science literature. But most of the di#erent approaches that use graphs are not used in a coherentway. There are di#erent models in use based on undirected or directed graphs, with or without multiple edges or loops. Sometimes graph elements are typed or at...

This paper presents an approach to program comprehension in multi-language systems. Such systems are characterized by a high amount of source codes in various languages for programming, database definition and job control. Coping with those systems requires the references crossing the language boundaries to be analyzed. Using the EEWGRAL approach to graph-based conceptual modeling, models representing relevant aspects gle language are built and integrated into a common conceptual model, Since conceptual modelingfocusses on specific problems, the integrated model presented here is especially tailored to multi-language aspects. Software systems are parsed and represented according to this conceptual model and queried by using a powerful graph query mechanism. This allows multi-language cross references to be easily retrieved. The multi-language conceptual model and the query facilities have been developed in cooperation with the maintenance programmers at an insurance company within the GUPRO project.