Abstract
In the object modeling for a product that consists of many parts, it is required to describe not only a shape of each of the parts but also relations among them.
In this paper, we propose a new product model for plate structures. Each of the parts is described as a predicate of prolog, which predicate consists of part's name and boundary-represented shape of the plate. Connectivity between two parts is also described by a predicate as a binary relation. Some fundamental concepts of local structure, that are important in design and manufacturing process, and their prolog implementation are shown.