An enterprise can be considered in a distributed computational paradigm. Multiagent systems have been invented to tackle such problems within artificial intelligence but are today seen also as a management methodology. The agent oriented abstraction has been proposed to describe in a fully generic way a society of agents. In this paper, we are investigating the application of this model to the abstract modeling of corporate knowledge. We show that such an abstraction mechanism leads to very practical applications whether on the web or on any other support and that it covers the broad scope of corporate knowledge. This approach can be further used to better simulate and support knowledge management processes.

Computer algebra systems (CASs) and automated theorem provers (ATPs) exhibit complementary abilities. CASs focus on efficiently solving domain-specific problems. ATPs are designed to allow for the formalization and solution of wide classes of problem

A mediator is a domain-specific tool to support uniform access to multiple heterogeneous information sources and to abstract and combine data from different but related databases to gain new information. This middleware product is urgently needed for these frequently occurring tasks in a decision support environment. In order to provide a front end, a mediator usually defines a new language. If an application or a user submits a question to the mediator, it has to be decomposed into several queries to the underlying information sources. Since these sources can only be accessed using their own query language, a query translator is needed. This paper presents a new approach for implementing query translators. It supports conjunctive queries as well as negation. Care is taken to enable information sources of which processing capabilities do not allow conjunctive queries in general. Rapid implementation is guided by reusing previously prepared code. The specification of the translator is done declaratively and domain-independently.

We present an approach towards a unified modeling and query processing tool for mediatory information systems. Based upon coloured Petri nets we are able to model the integration of parametric data (external, uncertain and temporal information) and to visualize the dataflow in mediatory information systems.

A shell is presented for hybrid knowledge representation. This system supports four different knowledge representation formalisms: first-order logic, terminological language, semantic networks, and production systems. The system automatically supports hybrid inferences taking into account the knowledge represented in different formalisms. All the algorithms involved in the inferences, supported by the system, are decidable, and have the property of being sound and complete according to a four-valued semantics. Besides these facilities, the shell allows the user to represent procedural knowledge of a domain using the primitives embedded at the heuristic level. The system has been implemented in Common Lisp, and makes use of an object-oriented extension for this language.>

This paper deals with the problem of finding Liouvillian solutions of an nth order homogeneous linear differential equation L(y)=0 with coefficients in a differential field k whose field of constants is C. For second order linear differential equations such an algorithm has been given by J. Kovacic and implemented. A general decision procedure for finding Liouvillian solutions of nth order equations has been given by M.F. Singer, but the resulting algorithm, although constructive, is not in implementable form even for second order equations. The algorithm uses the fact that, if L(y)=0 has a Liouvillian solution, then, L(y)=0 has a solution z such that u=z′/z is algebraic over k, which means that L(y) has a solution z of the form e∫u, where u is algebraic over k. Since the logarithmic derivative u=z′/z of a solution z is a solution of the Riccati equation R(y)=0 associated to L(y)=0, the problem thus reduces to find an algebraic solution u of R(y)=0. This task is now split into two parts: