ABSTRACT
Chapters 4 through 6 presented the details of IVA in an implementation-independent fashion. This chapter describes the implementation of VIRTUS and of VIRTUS applications. 124 VIRTUS, JESQ-II, RCTE, and ES-SHELL were completed largely at Stanford University, in a Xerox environment under Interlisp-D (Koto) and KEE 3.0. Additional VIRTUS components were developed at IBM’s Thomas J. Watson Research Center (Yorktown Heights, New York) under Common Lisp. FORECASTER, which includes the ES-SHELL knowledge base, was implemented at IBM in a System/370 VM environment under KnowledgeTool 1.0 and SAS. In the Stanford implementation, which we detail here, VIRTUS data structures are implemented in KEE frames and in INTERLISP structures, and VIRTUS algorithms are implemented in KEE control structures (inheritance, demons, etc.) and in INTERLISP procedures.
