B.N. Rossiter
D.A. Nelson
M.A. Heather
University of Newcastle upon Tyne. 1994
Category theory has been developed over the last 50 years as a multi-level mathematical workspace capable of modelling real-world objects. Categories of objects are manipulated in geometric logic by a single concept represented by the arrow. The category of products is an important instance of the universal concept of a limit now recognised to exist in many contexts. The product model provides a natural extension from relational structures on sets to a full formal description of features such as classes, objects, association abstraction, inheritance, views and query closure. The benefit for databases is that these can all be integrated formally through the arrow concept.