This work exploits Answer Set Programming (ASP) for reasoning in a rational extension of SROEL(⊓,×) [5], the low complexity description logic which underlies the OWL EL ontology language. It is based on a preferential approach to defeasible reasoning in description logics (DLs) [2, 3], which has been developed along the lines of the preferential semantics introduced by Kraus, Lehmann and Magido...

In this paper we solve the problem of the existence of rational realizations of response maps. Sufficient and necessary conditions for a response map to be realizable by a rational system are presented. We provide also the characterization of the existence of rationally observable and canonical rational realizations for a given response map.

The Jordan canonical form (JCF) of a square matrix is a foundational tool in matrix analysis. If the matrix A is known exactly, symbolic computation of the JCF is possible though expensive. When the matrix contains parameters, exact computation requires either a potentially very expensive case discussion, significant expression swell or both. For this reason, no current computer algebra system ...

A fundamental problem in classifying varieties is to determine natural subsets whose moduli is bounded. The difficulty of this problem is partially measured by the behaviour of the canonical class of the variety. Three extreme cases are especially of interest: either the canonical class is ample, that is the variety is of general type, or the canonical class is trivial, for example the variety ...

There is a good notion of rational functions with coefficients in a commutative ring. Using this notion, we easily obtain a neat generalization of Chapter 10 of the classical book by Kalman et al. to linear systems over an arbitrary commutative ring. The generalizations certainly exist already. However, we believe that the approach we present is more natural and straightforward. In this note we...