Re: How do RDF and Formal Logic fit together?

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.

Seth Russell

Received on Saturday, 13 October 2001 16:56:55 UTC