Re: How do RDF and Formal Logic fit together?

Seth Russell

> From: "Thomas B. Passin" <tpassin@home.com>
>
> > [Seth Russell]
> >
> > > From: "Pat Hayes" <phayes@ai.uwf.edu>
> > >
> > > > I agree that would be great, but unfortunately RDF isn't quite good
> > > > enough for that. Its just *too simple* to be useable as a general
> > > > syntax model. If it had used quadruples instead of triples, or had
> > > > some kind of context or scoping mechanism, or had some way to string
> > > > together sequences without forcing the use of reification; any of
> > > > those would have worked; but plain graphs just don't cut the
mustard.
> > >
> > > Well the pentuples of a mentograph would do the job, me thinks:
> > >
> > > 1) subject
> > > 2) property
> > > 3) object
> > > 4) statement ID
> > > 5) sequence
> > >
> > > ... which when you add some other needed typing info to make the data
> > > processing practical it ends up being a 7-tuple  see
> > > http://robustai.net/mentography/SemStructure3.gif   But you can still
> draw
> > > them as labeled directed pseudographs with an optional new sequence
> > > attribute labeling the arcs:
> http://robustai.net/mentography/sequence.gif
> > >
> >
> > You know, when you construct a computer model of an RDF graph, it's
> > practically impossible to do without having a triple be some kind of
> object
> > or entity.  It's a row in a database, or an edge definition showing
source
> > and target, or a tuple (subject, predicate, object), or something that
> gives
> > an (local) identity to each statement.
>
> Yes, definitely.  I think most implementations of RDF actually have this
> identifier already; all they need to do is expose it to the user.
>
> >Surely it wouldn't be much of a step
> > to generalize that in the model and specify a way to map from the
> inevitable
> > local identifier to a globally unique URI.
>
> Personally I don't think think it's necessary to have a globally unique ID
> for each triple and it may actually be misleading.   A triple only has
> meaning within a context.  If I assert the triple {:Goor :won
:Election2000}
> it has a totally different meaning than if the US Electorical College had
> asserted that same triple.  I suppose there are context independant
triples
> ... but I haven't personally run into any yet ... have you?   I think the
ID
> of a triple should be stamped locally by the person reading or writing the
> triple within some context.
>

Well, I'm not sure  - I was speculating that when to emit a globally unique
ID (or whether to do so) would be covered by  the mapping I mentioned.  You
could also have statement ids that were unique to a particular
serialization, too.  That would capture your kind of example, wouldn't it?
However this goes, the identifiers generally exist just waiting to be
exposed, so why not make it possible to do so?

Cheers,

Tom P

Received on Saturday, 13 October 2001 18:11:55 UTC