Affiliations: Department of Science and Technology, Linköping
University, S 601 74 Norrköping, Sweden | Centro de Inteligência Artificial (CENTRIA),
Department Informática, Faculdade de Ciências e Tecnologia,
Universidade Nova de Lisboa, 2829-516 Caparica, Portugal | Department of Computer and Information Science,
Linköping University, S 581 83 Linköping, Sweden
Abstract: This paper presents an expressive language for representing
knowledge about vague concepts. It is based on the rough set
formalism and it caters for implicit definition of rough relations
by combining different regions (e.g. upper approximation, lower
approximation, boundary) of other rough relations. The semantics
of the proposed language is obtained by translating it to the
language of extended logic programs whose meaning is captured by
paraconsistent stable models. A query language is also discussed
to retrieve information about the defined rough relations.
Motivating examples illustrating the use of the language are
described.
