- From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
- Date: Thu, 31 May 2001 11:01:57 -0400
- To: melnik@db.stanford.edu
- Cc: www-rdf-logic@w3.org
From: Sergey Melnik <melnik@db.stanford.edu> Subject: Re: What do the ontologists want Date: Wed, 30 May 2001 18:58:43 -0700 > "Peter F. Patel-Schneider" wrote: > > > > In defense of stripped-down RDF, there is nothing technically wrong with a > > logical formalism that can represent only positive ground triples. Such a > > formalism can certainly convey some useful semantic information. > > > > It is just that such a representation formalism cannot be used to > > *represent* anything more than positive ground triples. Using positive > > ground triples to encode a more-expressive formalism requires encoding, which > > requires a new semantics, defined on top of the semantics for the positive > > ground triples, and makes it essentially impossible to use the semantics > > for the positive ground triples to represent domain information. > > Is that true indeed? If a logical formula is encoded as a set of > statements, wouldn't it be possible to find an interpretation that maps > the corresponding resources into the domain of discourse, which contains > people, Web sites, logical formulae and classes? Sure, you could have an RDF ``predicate'' for disjunction and one for negation, etc., etc. However, there is no connection between the RDF predicates and disjunction or negation within RDF, and this mapping is precisely what I meant by a new semantics. > Wrt the latter: it is absolutely necessary to map resources that > represent classes onto sets of objects in the domain of discourse (D)? > Would it be possible to map such resources to elements of D that > represent classes and have certain relationships with their members? Sure, this can be done, but this is completely irrelevant to the encoding issue. > Sorry if the questions don't make sense - I'm not a logician. > > Best, > Sergey peter
Received on Thursday, 31 May 2001 11:02:47 UTC