- From: Antoine Isaac <aisaac@few.vu.nl>
- Date: Mon, 03 Aug 2009 23:55:29 +0200
- To: Thomas Bandholtz <thomas.bandholtz@innoq.com>
- CC: Jyotishman Pathak <jyotishman.mayo@gmail.com>, public-esw-thes@w3.org
By the way: > For what do you need it? > I can hardly imagine a use case. +1 I'd be really curious to know the motivation behind Jyoti's question... Antoine > > Thomas > > Jyotishman Pathak schrieb: >> Thomas, >> >> My understanding is that the last bit of information in your email >> does not hold: >> >> rdfs:Resource >> rdfs:Class >> owl:Class >> skos:Concept >> >> skos:Concept is rdf:type owl:Class (not subClassOf). So, I think the >> subClassOf hierarchy that you pointed out isn't holding...unless I am >> terribly missing something here. >> >> - Jyoti >> >> On Mon, Aug 3, 2009 at 12:44 PM, Thomas Bandholtz >> <thomas.bandholtz@innoq.com <mailto:thomas.bandholtz@innoq.com>> wrote: >> >> Hi Antoine & Jyoti, >> >> isn't it much more simple? >> >> in OWL, "owl:Class is defined as a subclass of rdfs:Class" [1]. >> >> <rdfs:Class rdf:ID="Class"> >> <rdfs:label>Class</rdfs:label> >> <rdfs:subClassOf rdf:resource="&rdfs;Class"/> >> </rdfs:Class> >> >> In RDFS you can read: >> >> "2.1 rdfs:Resource All things described by RDF are called >> resources, and >> are instances of the class rdfs:Resource. This is the class of >> everything. All other classes are subclasses of this class. >> 2.2 rdfs:Class This is the class of resources that are RDF >> classes." [2] >> >> <rdfs:Class rdf:about="http://www.w3.org/2000/01/rdf-schema#Class"> >> <rdfs:isDefinedBy >> rdf:resource="http://www.w3.org/2000/01/rdf-schema#"/> >> <rdfs:label>Class</rdfs:label> >> <rdfs:comment>The class of classes.</rdfs:comment> >> <rdfs:subClassOf >> rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/> >> </rdfs:Class> >> >> That's why skos:Concept does not need a subClassOf rdfs:Resource, >> it is >> inherited. >> Class hierarchy is: >> >> rdfs:Resource >> rdfs:Class >> owl:Class >> skos:Concept >> >> Hope this helps, >> >> Thomas >> >> [1] http://www.w3.org/TR/owl-ref/#Class >> [2] http://www.w3.org/TR/rdf-schema/#ch_resource >> >> >> Antoine Isaac schrieb: >> > Hi Jyoti, >> > >> > Indeed there is no explicit subClassOf relationship between >> > skos:Concept and rdfs:Resource. >> > >> > But it is implicitly here: if I'm not mistaken, an RDFS/OWL >> inference >> > engine can get it from the RDFS and OWL semantics, especially using >> > [1] which has the following axiom: >> > If x is in IC then <x, I(rdfs:Resource)> is in >> IEXT(I(rdfs:subClassOf)) >> > ( where IC = ICEXT(I(rdfs:Class)) ) >> > >> > Cheers, >> > >> > Antoine >> > >> > [1] http://www.w3.org/TR/rdf-mt/#vocabulary_entail >> > >> > >> > >> >> Hello all, >> >> >> >> I am seeking a clarification about skos:concept. >> >> >> >> <rdf:Description rdf:about="#Concept"> >> >> <rdfs:label xml:lang="en">Concept</rdfs:label> >> >> <rdfs:isDefinedBy >> rdf:resource="http://www.w3.org/2004/02/skos/core"/> >> >> <skos:definition xml:lang="en">An idea or notion; a unit of >> >> thought.</skos:definition> >> >> <!-- S1 --> >> >> <rdf:type rdf:resource="http://www.w3.org/2002/07/owl#Class"/> >> >> </rdf:Description> >> >> >> >> 1.) At present, skos:concept is defined as an instance of owl:class >> >> (and hence, an instance of rdfs:resource). However, I do not >> see any >> >> "explicit" subClassOf relationship between skos:concept and >> >> rdfs:resource. Am I correct in assuming that such a >> relationship does >> >> not exist? >> >> >> >> 2.) If the answer to question# 1 is yes, could you please explain >> >> (preferably with an example) why such an assertion was not included >> >> in the specification? >> >> >> >> Thank you in advance for your replies! >> >> >> >> Cheers, >> >> - Jyoti >> > >> > >> > >> >> >> -- >> Thomas Bandholtz, thomas.bandholtz@innoq.com >> <mailto:thomas.bandholtz@innoq.com>, http://www.innoq.com >> innoQ Deutschland GmbH, Halskestr. 17, D-40880 Ratingen, Germany >> Phone: +49 228 9288490 Mobile: +49 178 4049387 Fax: +49 228 9288491 >> >> > >
Received on Monday, 3 August 2009 21:56:09 UTC