This document proposes a protocol for accessing knowledge bases stored in frame knowledge representation systems (FRSs). The protocol, called Generic Frame Protocol (GFP), provides a set of Common Lisp functions that provide a generic interface to underlying FRSs. The interface layer allows an application some independence from the idiosyncrasies of specific FRS software and enables the development of generic tools (e.g., graphical browsers, frame editors) that operate on many FRSs.
This Generic Frame Protocol can be viewed as an extension of the Ontolingua system[], which provides a way to define classes, relations, and functions that can be translated into a variety of FRSs. Ontolingua is for declarative specification only, and does not provide a way to store and retrieve facts in a knowledge base. The Generic Frame Protocol allows one to write applications that use knowledge bases, including ontologies written in Ontolingua.
The GFP protocol is complementary to language specifications developed to support knowledge sharing. KIF [], the Knowledge Interchange Format, provides a declarative language for describing knowledge. As a pure specification language, KIF does not include commands for knowledge base query or manipulation. Furthermore, KIF is far more expressive than FRSs. The Generic Frame Protocol focuses on operations that are efficiently supported by most FRSs (e.g., operations on frames, slots, facets; inheritance and slot constraint checking).