- From: Valentin Zacharias <Zacharias@fzi.de>
- Date: Wed, 1 Aug 2007 10:48:28 +0200
- To: "Garret Wilson" <garret@globalmentor.com>, "Semantic Web" <semantic-web@w3.org>
Hi Garret, GW: >I'm creating an ontology in which it is useful to identify "any >resource". That is, let's say that I want to specify to which resource a >particular <eg:Rule> applies. I can specify (let me try my hand at N3 here); [...] >If I assume that the resources are people with emails, I could use ><mailto:*.*>. But that doesn't seem general enough---it's almost >too much of a hack. If I understand you correctly you want to say something like: if there is an resource ?A such that there is a triple (?A, foaf:mbox,?B) then there is a triple (eg:Rule,eg:applies,?A) ... you want to make statements about a subset of resources for which some condition holds ... I'ld use rules to represent that, for example with Jena' general purpose rule engine [1] you write this as: [Rule applies: (?A, foaf:mbox,?B) -> (eg:Rule,eg:applies,?A) No "wildcards", but "variables" that help you achieve the same. For many cases you can achieve the same with OWL by defining a class of all the resources you're interested, e.g. foaf:mbox rdf:type owl:ObjectProperty; rdfs:domain eg:PeopleWithEmail. >From this an OWL reasoner should conclude that every resource A for which there is a triple (A, foaf:mbox,*) is an instance of the class PeopleWithEmail - abd then you can use this class to make statement about your resources. [1]: http://jena.sourceforge.net/inference/#rules cu valentin -- email: zacharias@fzi.de phone: +49-721-9654-806 fax : +49-721-9654-807 http://www.vzach.de/blog ======================================================================= FZI Forschungszentrum Informatik an der Universität Karlsruhe (TH) Haid-und-Neu-Str. 10-14, 76131 Deutschland, http://www.fzi.de SdbR, Az: 14-0563.1 Regierungspräsidium Karlsruhe Vorstand: Rüdiger Dillmann, Michael Flor, Jivka Ovtcharova, Rudi Studer Vorsitzender des Kuratoriums: Ministerialdirigent Günther Leßnerkraus ======================================================================= -----Original Message----- From: semantic-web-request@w3.org on behalf of Garret Wilson Sent: Wed 8/1/2007 2:57 AM To: Semantic Web Subject: wildcard resource representation Everyone, I'm creating an ontology in which it is useful to identify "any resource". That is, let's say that I want to specify to which resource a particular <eg:Rule> applies. I can specify (let me try my hand at N3 here); [] a eg:Rule; eg:appliesTo <urn:uuid:92f01109-e08e-4ac2-b0d4-b13f65ba7595> That means that the rules applies to some identified resource. But is there any convention for identifying "any resource"? I see several options: * If I assume that the resources are people with emails, I could use <mailto:*.*>. But that doesn't seem general enough---it's almost too much of a hack. * Maybe there's a wildcard URI out there---that is, perhaps <urn:uuid:1234...> is universally agreed upon as the wildcard resource. But I'm not holding my breath that this exists. * Maybe I could create my own wildcard URI: <eg:wildcard>. But that seems too specific to my ontology. * What about a class of all resources? If I were to use <http://www.w3.org/2000/01/rdf-schema#Resource>, that doesn't seem to be what I'm wanting to say semantically---it would say that the rule applies to the class of resources, not to every instance of that class. * I could create a type <eg:AnyResource> and this could be the value of the eg:appliesTo property, but this seems to have the same problem as using the type <rdfs:Resource>. Any suggestions? There are almost limitless ways I can go with this, but is there some convention? Garret
Received on Wednesday, 1 August 2007 08:48:50 UTC