Re: RDF based messaging, negotiating, and dataset semantics

> On Jul 10, 2017, at 10:18 AM, Simon Spero <sesuncedu@gmail.com> wrote:
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> On Jul 9, 2017 4:44 PM, "Pat Hayes" <phayes@ihmc.us <mailto:phayes@ihmc.us>> wrote:
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>> On Jul 9, 2017, at 1:24 AM, Simon.Cox@csiro.au <mailto:Simon.Cox@csiro.au> wrote:
>> 
>> >> URIs which denote RDF graphs
>> 
>> Surely the issue is whether the URI denotes a *static* rdf graph. 
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> There is no such thing as a dynamic RDF graph. An RDF graph is defined to be a (mathematical) *set* of RDF triples, so is ‘static’ by definition.
> 
> Hmm.
> 
> It is true by definition that there can be no such thing as a (dynamic (RDF graph)), but it is possible that there could be such a thing as a ((Dynamic RDF) graph)

Well, there is an RDF container, which would be treated semantically as a function from times to graphs. That ought to do the trick.

> and that some semantics of such graphs could be chosen that allows for mapping a momentary slice of a graph into an RDF graph, and for mapping an RDF graph,  an "instant", and  possibly a dynamic RDF graph name(?)  into a Dynamic RDF graph slice. Any identifiers  in the mapped-to RDF graph might have to be temporary qualified. 

Messing with the semantics of URIs? That would be a long step beyind anything any RDF WG would have had in its charter :-)

> Choosing such a semantics obviously would  require care. A minimal semantics might not allow for any inferences to be drawn between "instants"; a relatively simple extension might allow for inferences to be made that hold for (e.g.) contiguous intervals during which the mapped-to RDF graph is unchanged ( lazy solutions to the frame problem). 

The great thing about dynamic sematnics is, usually inly the ‘now’ state is accessible to inference. In fact, if you are a dyed-in-the-wool presentist, only that state actually exists. 

Pat Hayes
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