Re: [Graphs] Proposal for Named Graph Semantics

Le 09/04/2011 00:27, Nathan a écrit :
> Antoine Zimmermann wrote:
>> I propose something that goes very much in the same direction as
>> Alex's proposal:
>>
>> Definition(Graph map) A graph map GM is a partial function from the
>> set of IRIs to the set of g-snaps.
>>
>> Definition(Temporal graph map) A temporal graph map TGM is a partial
>> function from [-inf,+inf] which maps a time point to a graph map.
>
> Nice, but if we define a mapping from a time point to a graph map, then
> how do you handle the case where a time point maps to multiple graph
> maps (for instance when you have auth* to consider)?

Well, we can see the map to be from the user agent's perspective: in any 
case, what the agent will get at one point in time is a single graph. Of 
course, a different agent, at the same time, can be served a different 
answer. So a server actually corresponds to possibly many different 
temporal graph maps, but what counts is that at the abstract level, the 
definition is the same and we can go on with defining the semantics 
independently of these implementation issues.

>
>> There exists a special temporal graph map, called the HTTPmap, such
>> that at any given point in time t, HTTPmap(t) maps a URI to the parsed
>> RDF graph of the document retrieved via an HTTP GET of the URI at the
>> time t. (if HTTP GET does not provide an RDF serialisation, then the
>> mapping is not defined on that URI).
>
> As above, doesn't consider auth*. At a single instant several different
> graphs may be associated with a specific URI.
>
> Thoughts?
>
> Best,
>
> Nathan


-- 
Antoine Zimmermann
Researcher at:
Laboratoire d'InfoRmatique en Image et Systèmes d'information
Database Group
7 Avenue Jean Capelle
69621 Villeurbanne Cedex
France
Tel: +33(0)4 72 43 61 74 - Fax: +33(0)4 72 43 87 13
Lecturer at:
Institut National des Sciences Appliquées de Lyon
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antoine.zimmermann@insa-lyon.fr
http://zimmer.aprilfoolsreview.com/

Received on Monday, 11 April 2011 12:22:36 UTC