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Re: More clearly warn that "generalized RDF" is non-standard

From: Gregg Kellogg <gregg@greggkellogg.net>
Date: Mon, 5 Aug 2013 14:56:08 -0700
Cc: public-rdf-wg@w3.org
Message-Id: <67FE32FC-0AFD-4997-A3D7-E3B291F50ECE@greggkellogg.net>
To: Charles Greer <cgreer@marklogic.com>
On Aug 5, 2013, at 1:21 PM, Charles Greer <cgreer@marklogic.com> wrote:

> Is it the case that N3 is a syntax for "generalized RDF"?  I'm bringing this up as a way to tie some concepts together; Notation-3 was recently put to me as a syntax for a superset of RDF, and it looks like the same superset that the term "generalized RDF" introduces.

It's partly there, but of course it's dataset model is also different than RDF datasets:

* Subjects can be URIs, BNodes or Literals
* Predicates can be URIs or BNodes
* Objects can be URIs, BNodes or Literals
* Graphs (formulae) are not named, although they can be equated with something else using the "=" predicate, which is shorthand for owl:sameAs (it was a different property in previous versions, AFAIR)
* Has existential and universal quantifiers defined implicitly or using @forAll and @forSome

Note that predicates can't be literals.

Some of the proposed changes to TriG move us close to much in N3, but probably not @keywords, quantifiers or any built-in notion of entailment other than standard RDF/RDFS entailment.

Gregg

> Charles
> 
> 
> 
> On 08/05/2013 01:08 AM, Andy Seaborne wrote:
>> On 02/08/13 17:50, David Wood wrote:
>>> Hi Andy,
>>> 
>>> 
>>> On Aug 2, 2013, at 12:42, Andy Seaborne <andy@apache.org> wrote:
>>> 
>>>> (why is this discussed on "comments"?)
>>> 
>>> It shouldn't have been.  My fault.
>>> 
>>> 
>>>> 
>>>> JSON-LD does not allowed the full range of "generalized RDF".
>>> 
>>> 
>>> Does any existing spec or implementation?
>> 
>> I don't know of one that has literals-as-predicates, which is not to say there aren't any.
>> 
>> I'm sure many systems implement this at the core level because internally they simple store term/term/term, but it's not visible to applications.
>> 
>> Literals-as-graph-names (which is in the original N-quads BTW) came up as a question recently:
>> 
>> http://answers.semanticweb.com/questions/23833/formulate-sparql-query-upon-n-quads 
>> 
>> dates/datetime for the quad label
>> 
>>    Andy
>> 
>>> Regards,
>>> Dave
>>> -- 
>>> http://about.me/david_wood
>> 
>> 
> 
> -- 
> Charles Greer
> Senior Engineer
> MarkLogic Corporation
> charles.greer@marklogic.com
> Phone: +1 707 408 3277
> www.marklogic.com
> 
> 
Received on Monday, 5 August 2013 21:56:38 UTC

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