this article.

Abstract not found

The notion of an instance is ubiquitous in knowledge representations for domain modeling. Most languages used for domain modeling offer syntactic or semantic restrictions on specific language constructs that distinguish individuals and classes in the application domain. The use, however, of instances and classes to represent domain entities has been driven by concerns that range from the strictly practical (e.g. the exploitation of inheritance) to the vaguely philosophical (e.g. intuitive notions of intension and extension). We demonstrate the importance of establishing a clear ontological distinction between instances and classes, and then show modeling scenarios where a single object may best be viewed as a class and an instance. To avoid ambiguous interpretations of such objects, it is necessary to introduce separate universes of discourse in which the same object exists in different forms. We show that a limited facility to support this notion exists in modeling languages like Smalltalk and CLOS, and argue that a more general facility should be made explicit in modeling languages.

Abstract not found

The paper attempts to explore high-level connectionist models for approximate commonsense reasoning from a broad perspective, investigating their connections to two other prominent paradigms: role-based reasoning and case-based reasoning. High-level connectionnist models, especially the CONSYDERR architecture, are studied in light of these paradigms.

An extended form of semantic network is defined, which can be regarded as a syntactic variant of the clausal form of logic. By virtue of its relationship with logic, the extended semantic network is provided with a precise semantics, inference rules, and a procedural interpretation. On the other hand, by regarding semantic networks as an abstract data structure for the representation of clauses, we provide a theorem-prover with a potentially useful indexing scheme and path-following strategy for guiding the search for a proof. Key Words and Phrases: logic, semantic networks, theorem-proving, indexing, resolution, deduction, logic programming

This article discusses Web metadata, which we define as "machine-understandable descriptions of Web resources." Web metadata has a number of uses, such as cataloging, software agents, and describing intellectual property rights. (For a description of Web metadata in applications, see the sidebar "Applications of Web Metadata.") RDF: AN