Re: How do RDF and Formal Logic fit together?

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

Contexts are done like: http://robustai.net/mentography/contexts.gif

Chris Caldwell at
http://www.utm.edu/departments/math/graph/glossary.html#pseudograph gives us
the following definition"

     "Formally: a pseudograph is a set V of vertices
      along, a set E of edges, and a function f from E to
      {{u,v}|u,v in V}. (The function f shows which
      vertices are connected by which edge.) An edge
      is a loop if f(e) = {u} for some vertex u in V."

A RDF graph is a special case of  a mentograph, but there is always a way to
transform any mentograph into a RDF graph and visa versa ... it just become
very tedious.   Basically we still have just labeled directed graphs with
sequence being an optional part of the label of an arc, and with arcs having
identity within a context.

Seth Russell

Received on Saturday, 13 October 2001 15:42:04 UTC