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From: Nathan Yergler <nathan-DXT9u3ndKiT7y3wIJjeDKkB+6BGkLq7r <at> public.gmane.org>
Subject: Re: How to negate cc:permits, cc:prohibits, cc:requires?
Newsgroups: gmane.org.creativecommons.metadata
Date: Thursday 20th August 2009 17:55:49 UTC (over 7 years ago)
Hi Patrick,

Sorry for such a delayed reply here.  I'm working on cleaning out my
reply queue and obviously this got stuck :).

As we've discussed off list, part of the answer here is better
communication of how ccREL models a copyright license.  ccREL assumes
a baseline of copyright and then offers additional permissions beyond
what's allowed under copyright.  Those permissions may be further
refined with prohibitions or requirements (ie, Commercial Use or
Attribution).  With this sort of model negating those individual terms
doesn't make a lot of sense.

With respect to OWL, a volunteer began the process of "porting" the
schema to OWL and at some point the process stalled.  As far as I know
there wasn't a technical issue, rather I think their need went away
(or changed).  If an OWL representation would be useful we'd
definitely provide review and hosting for it (as a peer with the RDF


On Fri, Jun 19, 2009 at 3:39 PM, Patrick
Peiffer wrote:
> Hi,
> I'm definitely not a semantic web specialist but these "Open World vs.
> Closed World issues" were raised in the W3C team comment on ccREL,
> http://www.w3.org/Submission/2008/02/Comment
> Is this a liability for integrating ccREL into an RDFS / OWL sematic
> environement?
> If yes, what does it take to change that? Nathan, how far did you go with
> OWL and what stopped you?
> Best, Patrick Peiffer
> cc-Luxembourg
> On Fri, Jun 19, 2009 at 10:37 PM, Christoph Lange
>  wrote:
>> Hi Nathan,
>> On Fri, Jun 19, 2009 at 7:14 PM, Nathan
>> Yergler wrote:
>> > If there are revisions we should consider, I'd be open to proposals.
>> thanks for your explanations. As far as my own work with ccREL is
>> concerned, my concerns were mostly theoretical, as I expect most of
>> our mathematical documents to use the standard CC licenses.
>> > In all the CC licenses, if Commercial Use is not explicitly
>> > prohibited, it is considered allowed.  We've previously looked at
>> > expressing this sort of additional information with OWL but haven't
>> > released anything.
>> However, I think that this kind of negation as failure is not
>> consistent with the open world assumption made by OWL and RDFS. If
>> Alice defines a custom license L in one of her documents and wants to
>> say that commercial use is allowed, her only choice is to say nothing,
>> i.e. to leave the RDF triple "L cc:prohibits cc:CommercialUse" out.
>> But what if Bob somewhere else on the web says "L cc:prohibits
>> cc:CommercialUse", and then some crawler crawls both Alice's and Bob's
>> definitions?
>> For that reason, I think it would be better to explicitly be able to
>> state negative facts.  Depending on how this is implemented in OWL,
>> one would be able to say in the ccREL ontology that e.g. "prohibits X"
>> and "permits X" contradict each other.  Then, in the scenario outlined
>> above, it could still happen that Alice's and Bob's contradicting
>> facts are merged together, but then any reasonable semantic web
>> software would _report_ this contradiction.
>> Not sure if you agree with that reasoning, and, if so, what you'd like
>> to do.  There is not so much traffic on this list, are there any
>> semantic web experts around?
>> Cheers,
>> Christoph
>> --
>> Christoph Lange, http://de.wikipedia.org/wiki/Benutzer:Langec,
>> 51191833
>> _______________________________________________
>> cc-metadata mailing list
>> [email protected]
>> http://lists.ibiblio.org/mailman/listinfo/cc-metadata
> _______________________________________________
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