- From: Alan Ruttenberg <alanruttenberg@gmail.com>
- Date: Sat, 20 Oct 2007 19:37:22 -0400
- To: Story Henry <henry.story@bblfish.net>
- Cc: Garret Wilson <garret@globalmentor.com>, Semantic Web <semantic-web@w3.org>
rdf:nil is something, specifically the empty collection. However, there is owl:Nothing, the empty class. If you say, for instance, that some property has allValuesFrom owl:Nothing, then it can't have any value. There is no thing which is rdf:type owl:Nothing. -Alan On Oct 20, 2007, at 12:25 PM, Story Henry wrote: > There is something close. rdf:Lists terminate with a null I think. > > Henry > > On 20 Oct 2007, at 18:15, Garret Wilson wrote: > >> >> As RDF evolved, was there any discussion on adding an rdf:null >> resource---that is, a resource that represents no resource at all? >> >> One expected response: "My child, you're thinking like a >> programmer again---what you really want to do is assert the >> absence of any assertions regarding a particular subject and >> predicate, or you want to assume a closed world and just don't >> assert anything at all", or something like that---and I appreciate >> this point of view to some extent. >> >> But as a practical matter, let's say we have a list of baseball >> game scores. Wouldn't it be convenient for the resource at index 3 >> to be null to indicate that there was no score that week because >> there was a tornado that canceled the game? >> >> I'm not necessarily looking for a big online discussion. Just a >> brief pointer to any reading on this subject would help. I'm sure >> there must have been some discussion of null over the development >> history of RDF. >> >> Thanks, >> >> Garret >
Received on Sunday, 21 October 2007 23:36:14 UTC