Doberkat, Ernst-ErichOmodeo, Eugenio G.2004-12-062004-12-0620032003-04-28http://hdl.handle.net/2003/267910.17877/DE290R-16053Entity-Relationship modelling is a popular technique for data modelling. Despite its popularity and wide spread use, it lacks a firm semantic foundation. We propose a translation of an ER-model into relation algebra, suggesting that this kind of algebra does provide suitable mechanisms for establishing a formal semantics of Entity-Relationship modelling. The work reported on here deals first with the techniques necessary for the translation, thus constructing a static view of an ER-model in an abstract setting of what might be called logic without variables. We then undertake a detailed analysis of the insertion and deletion operations for an ER-model represented in terms of the relation calculus.enUniversität DortmundInternes Memorandum des Lehrstuhls für Software-Technologie / Fachbereich Informatik, Universität Dortmund ; 132Entity-Relationship models (static and dynamic view)relational foundations of data modelling.relation algebra004working paper