Re: Graphs Design 6.2

Le 25/04/2012 13:44, Sandro Hawke a écrit :
> Here's a sketch of 6.2, which is similar to 6.1, but differs in the
> areas where people have made me think they didn't like it.  I have not
> put it on a wiki page or given it test cases yet.
> The differences are:
>    * Partial-graph semantics, instead of complete-graph semantics.  This
> is more quad-like, and may be seen as more in keeping with RDF's usual
> style of working with partial knowledge.   It makes it harder to reason
> about what's unsaid, but few people are doing that anyway.

Both semantics could coexist, with an indicator making explicit which 
one is assumed.

>    * A keyword "@union" may be given instead of the default graph,
> indicating the default graph is the union of all the named graphs.  This
> means everything in those graphs is asserted.    (Alternatively, we
> could have "@asserted", perhaps parameterized by "all" or the names of
> those graphs which are considered asserted.)

By "union", don't you mean "merge"?
If so, I already made the very same proposal in my email showing how the 
semantics of datasets [1] is addressing the use cases [2].

Unfortunately, this email was never discussed, nor commented, nor 
replied to at all. I'm even wondering whether it has been read.
It annoys me a lot that my proposal seems to be disregarded, when Pat's 
proposals, which have been always incomplete to various extent so far, 
are always getting a lot of attention.


>    * A class rdf:GraphAssociate containing all the things denoted by RDF
> terms used as labels in datasets.     The label is an IRI or bNode, the
> "associate" is the thing that IRI or bNode denotes.   The associate is
> associated with the given graph.  This is a superclass of rdf:Graph,
> because graphs have themselves as associates.   (I wouldn't mind a
> better word, but haven't thought of one.)
>    * A class rdf:GraphContainer, a subclass of rdf:GraphAssociate.  A
> GraphContainer differs from a Graph in that conceptually it can change
> over time.   [We don't say anything about how to deal with it changing
> over time, because (so far) RDF never talks about change-over-time.  If
> it did (such as with rdf:starting and rdf:ending predicates) then that
> solution would apply here as well.]   The trig document "{<u>  a
> rdf:GraphContainer}<u>  {<a>  <b>  <c>  }" is true at exactly those times
> that the Graph Container identified by "u" contains the triple expressed
> as "<a>  <b>  <c>".    [Note well: I did not say "contains ONLY" that
> triple.  Because of partial-graph semantics, the document is also true
> if<u>  also contains some other triples.]
> The rest of 6.1 remains the same, including global-scope bNode labels,
> bNodes allowed as graph labels, rdf:Graph, and rdf:hasGraph.   (I have
> an idea for 6.3, but I don't have time to think it through before
> today's meeting.)
>      -- Sandro

Antoine Zimmermann
ISCOD / LSTI - Institut Henri Fayol
École Nationale Supérieure des Mines de Saint-Étienne
158 cours Fauriel
42023 Saint-Étienne Cedex 2
Tél:+33(0)4 77 42 83 36
Fax:+33(0)4 77 42 66 66

Received on Wednesday, 25 April 2012 14:31:00 UTC