Re: model theory for RDF/S

From: Pat Hayes <phayes@ai.uwf.edu>
Subject: Re: model theory for RDF/S
Date: Thu, 27 Sep 2001 13:04:15 -0500

> >>  >17/ Because of the complexity of RDFS, I won't believe the Schema Lemma
> >>  >     until I see a completely worked out proof.
> >>
> >>  Fair enough. I no longer believe it myself. What I am sure of is that
> >>  there is *some* closure table for which it is correct, however. Also,
> >>  it should be stated so as to explicitly rule out the rdfs:Literal
> >>  class.
> >
> >Probably.  However there might not be a finite schema-closure for full RDF!
> 
> There must be, since the Herbrand universes are always finite. Until 
> one can build functional terms recursively, any set of generation or 
> closure rules is just going to do combinatorics on the finite set of 
> possible triples.
> 
> Pat

Not necessarily so, at least not in the thinking of at least one RDF
person.  I have heard comments to the effect that every statement in RDF
has a reification (although, of course, not vice versa).  This would, I
think, require an infinite Herbrand universe.

peter

Received on Thursday, 27 September 2001 14:29:52 UTC