Concept Language with Number Restrictions and Fixpoints, and its Relationship with Mu-calculus

Abstract. Many recent works point out that there are several possibilities of assigning a meaning to a concept definition containing some sort of recursion. In this paper, we argue that, instead of choosing a single style of semantics, we achieve a better result by adopting a formalism allowing for different semantics to coexist. In order to demonstrate the feasibility of our proposal, we present a knowledge representation language with the above characteristics. The language is a powerful concept language where, besides the usual constructs for conjunction, disjunction, negation, and quantifiers, both qualified number restrictions, and recursive definitions are allowed. Notably, these features make our formalism one of the most powerful concept languages proposed in literature, in which the usual frame-based descriptions can be combined with definitions of data structures such as lists, directed acyclic graphs, streams, etc. We show that reasoning in our language is decidable, and we ...

• Type: Conference
• Year: 1994
• Where: ECAI
• Authors: Giuseppe De Giacomo, Maurizio Lenzerini
• Keywords: Artificial Intelligence, Concept Definition, ECAI 1994, Knowledge Representation Language, Powerful Concept Languages