Sets and Functions: A Foundation for Digital Libraries, through Streams, Spaces, Structures, and Scenarios (S)

Digital Libraries in particular, and Information Systems in general, engender no consensus regarding theoretical foundations. In the trivial case, all information systems can be modeled mathematically as sets of information paired with the functions that operate on that information. Using the abstractions Streams, Spaces, Structures, and Scenarios (S4), we bridge the stark gap between the mathematical definition of a digital library and its pragmatic implementation by presenting a framework rich enough to encompass the wide variety of hypermedia information systems. We show how these abstractions may be implemented in HyTime and give examples related to the National Digital Library of Theses and Dissertations. We conclude by outlining an approach to open Digital Libraries based on HyTime constructs.