Reasoning within Fuzzy Description Logics
  Description Logics (DLs) are suitable, well-known, logics for managing
structured knowledge. They allow reasoning about individuals and well defined
concepts, i.e., set of individuals with common properties. The experience in
using DLs in applications has shown that in many cases we would like to extend
their capabilities. In particular, their use in the context of Multimedia
Information Retrieval (MIR) leads to the convincement that such DLs should
allow the treatment of the inherent imprecision in multimedia object content
representation and retrieval. In this paper we will present a fuzzy extension
of ALC, combining Zadeh's fuzzy logic with a classical DL. In particular,
concepts becomes fuzzy and, thus, reasoning about imprecise concepts is
supported. We will define its syntax, its semantics, describe its properties
and present a constraint propagation calculus for reasoning in it.
