Many expert systems have been developed over the past decades. ProGrammar is a modest expert system shell that has been developed recently. It is built on top of the CProlog/UNIX* system running on a VAX† 11/750. ProGrammar is designed for processing and developing grammars. It can also be used as a knowledge base constructor for other fields besides grammars, a learning tool, a Prolog interpreter, and as a consulting system. ProGrammar is an interactive system meaning not only can the user query ProGrammar but ProGrammar also can question the user. The user is allowed to request an explanation from the ProGrammar on how the solution to the query was derived. / Science, Faculty of / Computer Science, Department of / Graduate