W3C home > Mailing lists > Public > public-rdf-wg@w3.org > September 2012

Re: different Semantics proposals (Re: Agenda for 19 Sep 2012)

From: Pat Hayes <phayes@ihmc.us>
Date: Tue, 18 Sep 2012 14:10:35 -0500
Cc: "Peter F. Patel-Schneider" <pfpschneider@gmail.com>, David Wood <david@3roundstones.com>, "public-rdf-wg@w3.org Group WG" <public-rdf-wg@w3.org>
Message-Id: <3E951264-5A46-4ECC-BE0C-9AC56C003225@ihmc.us>
To: Sandro Hawke <sandro@w3.org>

On Sep 18, 2012, at 9:40 AM, Sandro Hawke wrote:

.....

>   The one thing I can argue for, I think, is that the graph names be strongly connected to those same names being used in the default graph.   For example, I think we need to be able to say things like this:
> 
> <http://example.org/d1> { <a> <b> 1 }.
> <http://example.org/d1> eg1:lastModified "Wed, 12 Sep 2012 11:42:31 GMT".
> 
> where eg1:lastModified is defined such that this dataset conveys the knowledge that (1) a dereference on URL "http://example.org/d1" was done; (2) it resulted in (at least?) the triple 
> { <a> <b> 1 }; and (3) the HTTP Last-Modified header returned during that dereference was the string "Wed, 12 Sep 2012 11:42:31 GMT".

I agree this would be very useful, and is strongly suggested by the usage where these are called "named graphs".  Unfortunately, this is not consistent with the proposed 'minimal' semantics, because that semantics allows <N, G> to be true when N does not denote G, but rather denotes something else which has a relationship to a graph which has an entailment relation to G; and the RDF semantics means that when that URI is used in RDF, it refers to that something else. There is no way here to use a URI in an RDF triple to refer to a graph. 

Pat

------------------------------------------------------------
IHMC                                     (850)434 8903 or (650)494 3973   
40 South Alcaniz St.           (850)202 4416   office
Pensacola                            (850)202 4440   fax
FL 32502                              (850)291 0667   mobile
phayesAT-SIGNihmc.us       http://www.ihmc.us/users/phayes
Received on Tuesday, 18 September 2012 19:11:07 GMT

This archive was generated by hypermail 2.3.1 : Tuesday, 26 March 2013 16:25:51 GMT