A Z specification of the soft-link hypertext model

This paper provides a formal specification in Z of a new intelligent hypertext model called the soft-link hypertext model (SLHM). This model has been implemented and extensively tested, and provides a new methodology for constructing the future generation of information retrieval systems. Its core is the adoption of a data structure called the conceptual index, which allows hypertext structure to be built automatically upon conventional Boolean systems. The functionality of resulting systems using this approach is then extended from Boolean search to more sophisticated information retrieval applications, including associative searches and information browsing. Compared with other similar projects, SLHM has the following three major advantages. First, the conceptual index is automatically formulated. Second, powerful neural learning mechanisms are applied to the conceptual index, thereby improving its efficiency and applicability. Third, machine intelligence installed on the conceptual index can be utilised for online assistance during navigating and information browsing. This specification has been developed by application of an existing formal framework for specifying hypertext systems. The specification presented here provides: a formal account of the state and operations of this new model; a sound basis for instantiations of the model to be built; a case study in the application of an existing formal framework; and an environment in which further refinements of new learning and hypertext strategies can be presented and evaluated.