Re: How do you deprecate URIs? Re: OWL-DL and linked data

On 15 Jul 2008, at 18:15, Booth, David (HP Software - Boston) wrote:

>> From: Michael Schneider
>>
>> On 10 Jun 2008, Bernard Vatant wrote:
>> [ . . . ]
>>> My first thought was to flag the downlode.org URIs with
>> something like
>>> owl:DeprecatedIndividual
>>> <http://downlode.org/rdf/iso-639/languages#da>
>>> owl:DeprecatedIndividual    "True"
>
> It is the *URI* that you wish to deprecate -- not the resource  
> denoted by that URI, so the deprecation statement *must*

Not really.

> be written something like this:
>
>   "http://lingvoj.org/iso-639/languages#da"^^xsd:anyURI
>       owl:deprecatesURI
>          "http://downlode.org/rdf/iso-639/languages#da"^^xsd:anyURI  .
>
> using "" rather than <> to indicate that you are talking about the  
> URI itself, rather than the resource denoted by that URI.

You could easily figure it out from context.

> The Semantic Web community does not yet seem to be accustomed to  
> taking about URIs themselves,

People make use/mention slides all the time. In all sorts of context.  
Sometimes it matters. Sometimes it doesn't. I don't know which it is  
in this case.

> but there is no getting around the need to do so.  So we just need  
> to get used to it.

I'm skeptical.

>> [ . . . ]
>> OWL 2 DL won't define any (reasoning) semantics for
>> annotation properties.  So owl:sameAs will *not* transfer the
>> deprecation triple to the other URI.
>> (Again, this is the current state, which might change before OWL 2 DL
>> becomes a W3C recommendation.)
>
> This *must* changed to make OWL 2 DL a monotonic extension of RDF:
> http://www.w3.org/TR/rdf-mt/#MonSemExt

First, I don't think there is a monotonicity requirement. Certainly  
not expressed from that section.

Second, I don't see that this is nonmonotonic. OWL DL isn't an  
extension of RDF or RDFS. This is well known. (It's an extension of a  
subset of them.)

(Indeed, it would be madness to so require. You can't make a non- 
monotonic extension of RDF? Huh? How could you stop anyone?)

>>
>> In OWL 2 Full, being an RDF compatible language, it is not  
>> possible to
>> define such a kind of "semantic-freeness". Here, owl:sameAs
>> *will* transfer the deprecation triple to the other URI.
>
> Exactly.  But OWL 2 DL should *also* conform to RDF's requirement  
> of semantic monotonicity.

There is no such requirement.

> Indeed, it wouldn't make sense for OWL 2 DL to be non-monotonic and  
> OWL 2 Full to be monotonic.

I don't think you are using non-monotonic standardly :) OWL 2 DL is  
monotonic, for sure, no question, as it stands now. It may or may not  
be a monontonic extension of RDFS (that is, the entailments of RDFS  
are a subset of the entailments of OWL DL). Of course, this isn't  
true (in some loose sense) for OWL DL, since not all RDFS graphs are  
legal WFFs of OWL DL. So any entailment of RDFS involving such graphs  
are not entailments of OWL DL.

Please keep the temperature down. Getting all insistent and *excited*  
is likely to irk SOMEONE (maybe me :)).

Even if OWL 2 DL were nonmonotonic in some sense, I sincerely doubt  
that saying "MUST" a lot will be convincing. Use cases and technical  
points tend to be moreso (at least to me).

Cheers,
Bijan.

Received on Tuesday, 15 July 2008 17:39:58 UTC