The multimedia knowledge-based system (MMKS) is a knowledge-based system which provides a uniform environment for flexible human-machine communication using multiple media. MMKS has a knowledge representation method called predicate logic based on objects (PLOB) and an object-base defined based on a relational data model. PLOB is a first-order predicate logic in which every individual is regarded as an object, e.g. an integer, a string, and an image. The object-base is a collection of relations, and a relation is a set of tuples of objects. The management function of the object-base is defined based on SQL. The authors present the definition of MMKS and MMKS systems implemented on workstations.>

A Knowledge-based System with Audio-Visual Aids (KS/AV) is presented. KS/AV is a knowledge-based system that has multiple types of knowledge represented not only in symbols but in audio-visual (AV) images, and it provides an environment for humanmachine communication through AV media. We define a predicate logic based on objects for knowledge representation in KS/AV. It is a first order predicate logic in which every individual is regarded as an object. All of the individuals including AV images are regarded as objects. Their definitions are based on the class concepts of Smalltalk-80. AV image objects presented in this paper include not only simple video and graphic images, but also composite images that consist of several component images. This paper presents the KS/AV system developed on a small computer system with various AV equipment. As a case study, we developed a reading advisory system for children on KS/AV, which communicates with children through AV images and gives their favourite picture books.