- From: Bijan Parsia <bparsia@cs.man.ac.uk>
- Date: Fri, 10 Aug 2007 11:11:52 +0100
- To: Garret Wilson <garret@globalmentor.com>
- Cc: Semantic Web <semantic-web@w3.org>
On Aug 10, 2007, at 2:09 AM, Garret Wilson wrote: > > Everyone, > > I promise I'm not trying to dig up the "replace literals with > normal resources" discussion, although I'm still strongly for that > proposal. I have an honest question about plain literal semantics, > however. At http://www.w3.org/TR/2004/REC-rdf-mt-20040210/ > #urisandlit I read: > > "Plain literals are considered to denote themselves, so have a > fixed meaning." > > Is this a typo? No. > It's not the most natural sentence I have no problem with the part you have problem with. (I'm not a fan of the "are considered to" part rather than just "Plain literals denote themselves...". > ---does it mean, "and thus always have a fixed meaning", or "and > and so have no fixed meaning?" I have no idea why you are getting the second reading. Replace "so" with "thus". If you replace it with "thus not" you've clearly changed the meaning. The semantic point is that plain literals always denote a particular object, whereas URIs (for example) can denote different things in different documents (or in different models of the same graph). That is, I can use http://example.org/soGreat to denote me and you can use it to denote you (each in our own Foaf file). In OWL, But I can only use "Bijan is so Great" to denote that very string. The meaning is, as they say, fixed. > Next question: how do plain literals differ semantically from typed > literals with a datatype URI of xsd:string? They can have a lang. Datatyped literals cannot. It was a big deal. It is clearly a wart. [snip] If I may make what is is intended to be a friendly comment: You are expending a ton of effort on the clearly marginal. That has significant opportunity costs.
Received on Friday, 10 August 2007 10:12:01 UTC