The goal of the paper is to analyse some specific features of a very central concept for top-level ontologies for information systems: i.e. the concept of artefact. Specifically, we analyse the relation to be a copy of that is strongly linked to the notion of artefact and—as we will demonstrate—could be useful to distinguish artefacts from objects of other kinds. Firstly, we outline some intuitive and commonsensical reasons for the need of a clarification of the notion of artefact in ontologies (...) for information systems, and we analyse some characterisations of the notion given by two top-level ontologies (Cyc and Wordnet). Secondly, we introduce and critically analyse Tzouvaras’ notion of copy. Thirdly, we try to complete an analysis of copy by distinguishing three kinds of copies: replicas (Tzouvaras’ notion of copy), rigid copies, and functional copies. With the help of these three notions we outline a first and preliminary distinction between artefacts, objects of art and natural objects. (shrink)

A continuum is here a primitive notion intended to correspond precisely to a path-connected subset of the usual euclidean space. In contrast, however, to the traditional treatment, we treat here continua not as pointsets, but as irreducible entities equipped only with a partial ordering ≤ interpreted as parthood. Our aim is to examine what basic topological and geometric properties of continua can be expressed in the language of ≤, and what principles we need in order to prove elementary facts about (...) them. Surprisingly enough ≤ suffices to formulate the very heart of continuity (=jumpless and gapless transitions) in a general setting. Further, using a few principles about ≤ (together with the axioms of ZFC), we can define points, joins, meets and infinite closeness. Most important, we can develop a dimension theory based on notions like path, circle, line (=one-dimensional continuum), simple line and surface (=two-dimensional continuum), recovering thereby in a rigorous way Poincaré's well-known intuitive idea that dimension expresses the ways in which a continuum can be torn apart. We outline a classification of lines according to the number of circles and branching points they contain. The ordering (C,≤) is a topped and bottomed, atomic, almost dense and complete partial ordering, weaker than a lattice. Continuous transformations from C to C are also defined in a natural way and results about them are proved. (shrink)