Types, algebras and modeling

Programming languages, database systems and artificial intelligence systems all have the notion that entities can be classified into types . As might be expected, however, the usage of the notion of type is not the same throughout or even within these areas. In this paper, I propose a notion of typing that is derived from work on programming languages and indicate how this notion might be used in the context of database systems. Thus, the paper is a step toward unifying the notions of type in data-bases and programming languages.