Georg Gottlob, Gerti Kappel, Michael Schrefl. The Evolving Algebra Semantics of Class and Role Hierarchies. In Leonid Libkin, Bernhard Thalheim, editors, Semantics in Databases, Selected Papers from a Workshop, Prague, Czech Republic, 1995. Volume 1358 of Lecture Notes in Computer Science, pages 92-113, Springer, 1995.
Abstract is missing.