In our implementation of geometric resolution, the most costly operation is subsumption testing (or matching): One has to decide for a three-valued, geometric formula, if this formula is false in a given interpretation. The formula contains only atoms with variables, equality, and existential quantifiers. The interpretation contains only atoms with constants. Because the atoms have no term stru...

Since its formulation, pattern mining has been focused both in the development of mining algorithms and in its extension to address new challenges, like the discovery of structured patterns. In both cases, existing approaches are now effective and efficient. However, and despite pattern mining is a constrained problem by definition, there is no generally accepted solution to incorporate domain ...

Preferential extensions of classical logics provide a promising foundation on which to base notions of entailment for defeasible reasoning. In this talk I will give an overview of one such a preferential extension, originally proposed by Sarit Kraus, Daniel Lehmann, and Menachem Magidor. This approach has two main advantages. Firstly, it permits a formal analysis of defeasible properties, which...

Mitchell de ned and axiomatized a subtyping relationship (also known as containment, coercibility, or subsumption) over the types of System F (with \!" and \8"). This subtyping relationship is quite simple and does not involve bounded quanti cation. Tiuryn and Urzyczyn quite recently proved this subtyping relationship to be undecidable. This paper supplies a new undecidability proof for this su...

Real-time, adaptive control is a difficult problem that can be addressed by EC architectures. We are interested in incorporating into an EC architecture some of the features that Holland’s Echo architecture presents. Echo has been used to model everything from cultures to financial markets. However, the typical application of Echo is a simulation to observe the dynamics of the modeled elements ...

The problem of rewriting a concept given a terminology can informally be stated as follows: given a terminology T (i.e., a set of concept deenitions) and a concept description C that does not contain concept names deened in T , can this description be rewritten into a \related better" description E by using (some of) the names deened in T ? In this paper, we rst introduce a general framework fo...

The paper introduces LOGAN-H —a system for learning first-order function-free Horn expressions from interpretations. The system is based on an algorithm that learns by asking questions and that was proved correct in previous work. The current paper shows how the algorithm can be implemented in a practical system, and introduces a new algorithm based on it that avoids interaction and learns from...

Distributed Description Logics (DDL) enable reasoning with multiple ontologies interconnected by directional semantic mapping, called bridge rules. Bridge rules map concepts of a source ontology into concepts of a target ontology. Concept subsumptions of the source ontology can be propagated according to a propagation pattern expressed by bridge rules into concept subsumptions of the target ont...