This paper is mainly concerned with the relation-algebraical aspects of the well-known Region Connection Calculus (RCC). We show that the contact relation algebra (CRA) of certain RCC model is not atomic complete and hence infinite. So in general an extensional composition table for the RCC cannot be obtained by simply refining the RCC8 relations. After having shown that each RCC model is a con...

The RDF Data Cube vocabulary is a catalyst for the availability of statistical Linked Data: raw statistical Linked Data are easy to model in, publish to, and retrieve from the Linked Data cloud. In statistical datasets, concepts are central entities represented by variables and their values. The meaning of these concepts is often assumed to be stable, but in fact it can change over time: we cal...

The proofs of major results of Computability Theory like Rice, Rice-Shapiro or Kleene’s fixed point theorem hide more information of what is usually expressed in their respective statements. We make this information explicit, allowing to state stronger, complexity theoretic-versions of all these theorems. In particular, we replace the notion of extensional set of indices of programs, by a set o...

The normative version of RDFS gives non-standard (intensional) interpretations to some standard notions such as classes and properties. In this paper we develop the extensional semantics for the RDFS vocabulary, which surprisingly preserves the simplicity and computational complexity of deduction of the intensional case. This result will impact current implementations in a positive sense, as re...

Versioning of components in a system is a well-researched field where various adequate techniques have already been established. In this paper, we look at how versioning can be extended to cover also the structural aspects of a system. There exist two basic techniques for versioning intentional and extensional and we propose a unified extensional versioning model for versioning of both componen...