- From: pat hayes <phayes@ai.uwf.edu>
- Date: Tue, 29 May 2001 11:41:35 -0500
- To: Graham Klyne <GK@NineByNine.org>
- Cc: www-rdf-logic@w3.org
>At 01:52 PM 5/27/01 -0400, Jonathan Borden wrote: >>This argument is oft stated. And in the early days of software, similar >>arguments were made regading the lack of ability of a high level language to >>express anything beyond what is expressed in machine language. > >That is very different from the argument I am advancing. I am >saying that triples are something in which the various "high level >languages" of resource description might be grounded, and (assuming >adequate semantics) through which the various forms of "high >language may" be related. Let me home in on this. A problem, I think, with a lot of this discussion, is that words like 'grounded' and 'related' are used without being clearly defined. There is certainly one sense in which any notation can be 'grounded' in triples, or represented as triples, since any graph can be encoded as a collection of triples. OK, let us agree on that. And these structures can be used to encode all of the syntactic forms of various "high-level" languages, which can be provided with suitable semantics, presumably. All of that is uncontroversial. The heat is generated when one tries to fit these together. The RDF model tries to attach the semantics directly at the triples level, which forces it to use reification as a kind of universal syntactic solvent. That is what some of us find an unacceptable trade-off, as it uses a huge burden of semantic expressivity (KIF is probably the only formalism on the planet with a fully defined truth predicate, and even that has never been used in practice by anyone, as far as I know, and is likely to be eliminated from the new KIF standard) to purchase a tiny advantage in interoperability (the property that any set of triples is well-formed.) Also, we are pretty sure it is going to lead to problems later: it is notoriously easy to produce paradoxes if used casually, it renders any 'genuine' usage of reification semantically suspect, and so on. >[...] >> > >> > I think their is a fair community investment in the triple form, and that >> > it should not be discarded unless we are certain that it is fundamentally >> > inadequate. >> >>I submit that the community investment is in _arcs and nodes_ not triples >>per se. > >I view "arcs and nodes" (as in directed labelled graphs) and >"triples" as different presentations of what is fundamentally the >same syntax. I would respectfully suggest that you might want to re-think this identification; or at least, that you distinguish *syntax* from *structure*. A single structure can encode a variety of different syntaxes, but the logical semantics needs to have the actual syntax to attach to, not its implementation structure. Pat Hayes --------------------------------------------------------------------- IHMC (850)434 8903 home 40 South Alcaniz St. (850)202 4416 office Pensacola, FL 32501 (850)202 4440 fax phayes@ai.uwf.edu http://www.coginst.uwf.edu/~phayes
Received on Tuesday, 29 May 2001 12:41:42 UTC