NIELSEN@KL.SRI.COM (Norm R. Nielsen) (04/30/88)
Information Industries Divisional Seminar Joshua: A System That Provides Syntactically Uniform Access to Heterogeneously Implemented Data Bases Steve Anthony Symbolics May 11 at 10 AM, BS-208 Joshua is a system developed at Symbolics that provides syntactically uniform access to heterogeneously implemented knowledge bases. Its power comes from the observation that there is a "protocol of inference" consisting of a small set of abstract actions, each of which can be implemented in many ways. The object-oriented programming facilities of Flavors have been used to control the choice of implementation. Each statement in the language represents an instance of a class identified with that statement's predicate. Steps of the protocol are implemented by methods inherited from the classes. Since inheritance of protocol methods is a compile- time operation, very fine-grained control can be achieved with little run-time cost. Joshua offers two major advantages. First, a Joshua programmer can easily change his or her program to use more efficient data structures without changing the rule set or other knowledge-level structures. Second, it is easy to build interfaces which incorporate existing tools into Joshua, without having to modify those tools. Steve Anthony will discuss the capabilities and design of Joshua, followed by some demonstrations. We will be meeting in the Intelligent System Laboratory's computer room so that the demonstrations can be run live on the Symbolics 3670. ------- -------