60. The computer as claimed in claim 59, wherein said separate portion of said knowledge base encoding said control knowledge comprises a plurality of discrete control blocks, each control block including statements in said imperative procedural language, said procedural language including separate statements to ask the user a question and obtain a responsive answer, apply a specified set of said judgmental rules, display to the user the conclusions of the rules applied, and to execute another specified control block.
61. The computer as claimed in claim 60, wherein said factual knowledge includes means for declaring at least one class of objects, said knowledge base includes means for causing distinct instances of said class to be created when the knowledge base is interpreted during a consultation, wherein said plurality of discrete control blocks includes at least one post-instantiation control block associated with said class, and wherein said procedural language interpreter comprises means for interrupting the execution of said procedural language to execute the procedural language statements in the post-instantiation control block associated with said class when an instance of said class has been created.