SKS@XX.LCS.MIT.EDU (Sunil Sarin) (02/18/86)
From: Sunil Sarin <SKS@XX.LCS.MIT.EDU> [Forwarded from the MIT bboard by SASW@MIT-MC.] CCA Colloquium Series DATE: February 20, 1986-- Thursday TIME: 10:00-11:00 a.m. PLACE: 4th floor large conference room, Four Cambridge Center TITLE: Deductive Databases and a Relational Knowledge Base A Survey of Work at ICOT, Japan SPEAKERS: Haruo Yokota and Masaki Murakami (Institute for New Generation Computer Technology (ICOT--Japan) ) CCA (Computer Corporation of America) is located at Four Cambridge Center, which is on Broadway, behind Legal Seafood. Tell the security desk you are visiting CCA and they will send you up to CCA on the 5th floor. Tell CCA's receptionist to call Barbara Wong who will show you where the seminar is. (If you can't remember that, simply say you're here for the colloquium.) Abstracts of works to be covered: 1. Deductive Database System based on Unit Resolution by Haruo Yokota, Ko Sakai, Hidenori Itoh This paper presents a methodology for constructing a deductive database system consisting of an intensional processor and a relational database management system. A setting evaluation is introduced. The intensional processor derives a setting from the intensional database and a given goal and sends the setting and the relationship between setting elements to the management system. The management system performs a unit resolution with setting using relational operations for the extensional databases. An extended least fixed point operation is introduced to terminate all types of recursive queries. 2. A Model and an Architecture for a Relational Knowledge Base by Hauro Yokota, Hidenori Itoh A relational knowledge base model and an architecture which manipulates the model are presented. An item stored in the relational knowledge base is a term, and it is retrieved by unification operation between the terms. The relational knowledge base architecture we propose consists of a number of unification engines, several disk systems, a control processor, and a multiport page-memory. The system has a knowledge compiler to support a variety of knowledge representations. 3. Formal Semantics of a Relational Knowledge Base by Masaki Murakami, Hauro Yokota, Hidenori Itoh A mathematical foundations for formal semantics of term relations [Yokota et al. 85] is presented. A term relation is a basic data structure of a relational knowledge base. It is an enhanced version of relational model in a database theory. It may include syntactically complex structures such as terms or literals containing variables as items of relations. The items are retrieved with operations called retrieval-by-unification. We introduce as a semantic domain of n-ary-term relations n_T_RELATIONS and define a partial order on them. We characterize retrieval-by-unification as operations on n_T_RELATIONS with monotone functions and greatest lower bounds.