- From: Bijan Parsia <bparsia@isr.umd.edu>
- Date: Fri, 1 Jul 2005 02:09:26 -0400 (EDT)
- To: drew.mcdermott@yale.edu, www-rdf-rules@w3.org
---- Original message ---- >Date: Fri, 1 Jul 2005 00:03:54 -0400 >From: Drew McDermott <drew.mcdermott@yale.edu> >Subject: Re: Web Rule Language - WRL vs SWRL >To: www-rdf-rules@w3.org > >> >> [Bijan Parsia] >> >> The old Layering Story has been bankrupted in several different >> >> ways. >> [me] >> > I'll take advantage of this crack in the orthodox Wall of Opprobrium >> >> I don't know how you determine your factions, but this really makes no >> sense. > >Sorry; I admit that my factionometer is not as accurate as it should be. I think your local muffler shop should be able to do a recalibration :) >> (The Old Layering Story is that every semantic web language should be a >> same syntax semantic extension of RDF. In this current thread, I think >> only Jim ever strongly endorsed that approach, and most of the major >> proponents, afaict, have weakened or abandoned it. Peter has a paper in >> ICJAI showing that it is paradoxical if extended to FOL. I find it a >> PITA for OWL and have argued vehemently, with major grade vehemence for >> the truth of my PITA pain. > >Well, Ian said this a couple of days (and many messages) ago --- > >> Regarding the existing layered architecture of OWL, and the proposed >> extension to SWRL, nobody (well not me anyway) claims that it is >> perfect, and there will (as Holger has pointed out) no doubt be some >> compatibility issues between different tools, but the situation is >> hardly comparable to the one that is being proposed in the "updated >> layer cake": as we have seen, even the very limited degree of >> interoperability suggested by this diagram turns out to be a chimera. >> In contrast, RDF, OWL and SWRL share a common semantic framework, and >> allow for a relatively clean layering: OWL-Lite, OWL-DL and SWRL are >> layered on a subset of RDF, but share the same semantics (and it can be >> syntactically determined when RDF ontologies are within this subset). > >--- so the Old Story can still be wheeled out when needed. There's a nuance. > Again, if >I have missed a nuance, I apologize. Apology accepted. > As far as I can tell, "layering" >is completely meaningless, but perhaps there are degrees of >meaninglessness. Perhaps the real issues is that meaninglessness things can be written into charters and then force a group to act as if they had meaning...which is nasty. >> [...] >> Well, this is familiar from you, Drew, and good to have it on the >> table. However, I don't think either Ian nor I are arguing against >> non-mon *per se*. I might argue against quasi-proceduralism, but that >> doesn't put me on a different side than Michael, as far as I know. > >I guess I should have kept my mouth shut, because obviously I don't >understand the argument. Well, given MIchael's reply, evidently I don't understand *his* argument, or, it may see, yours. So I guess I should have kept *my* mouth shut. [snip] >> I wonder what you think of all the work in formal semantics for LP. >> Minimal model, perfect model, Well founded, answer set.... > >Here's the nub: We are in the presence of an unfortunate pun. All of >these different "semantics" for LP concern the meaning of logic >programs _as programs_. But for interoperability what we care about >is the semantics of logical expressions as _statements_. So when Ian >says Ok. That seems to accord with what Michael said in the follow up. I'm not sure I buy it, but ok. >> This isn't the argument: the argument is about (lack of) >> interoperability between two formal systems. No one is (yet) claiming >> that either of these systems is pixie dust. > >I am somewhat baffled. If two systems use the same syntax, and employ >the same vocabulary with the same (Tarskian) semantics, then they can >interoperate by exchanging messages. The fact that they may have used >different methods in order to arrive at their conclusions is >important, but has nothing to do with interoperability per se. (I'll >anticipate the objection that there has to be a standard proof or >justification language so that a module needn't believe a statement >unaccompanied by a proof; a Methodist system can refuse to believe the >testimony of a Baptist system. Having anticipated it, I will simply >say that I am deeply skeptical about the possibility of such a >justification system.) If I send a message intending for it to be understand *as a program* and you receive it understanding it *as statement*, then it seems that we have a divergence in understanding. Perhaps this is trivial, as MIchael said, or is swamped by other facts about my interpretation context. I don't think that requires an accompanying justification or proof. >> [...] >> I'll be interested to know if Michael thinks this is a defense of him :) > >Yes, he's probably preparing a statement disavowing everything I've >said. Well, I tried. You tried better than I thought :) He seems to think you're on the money! >> I guess I just find this too vague to get a grip on. What's your >> proposal? Is ISO Prolog a reasonable starting place? Some more modern >> logic/functional programming language? Should we just add a few things >> to XQuery? >> >> I just don't know how to take your POV and generate useful >> standardization activities. Do you think there are none? (That's not >> unreasonable.) > >My proposal is type theory, or, failing that, Common Logic with a >strongly typed syntax in front of it. How about LF? > But this is a proposal for a >notation for exchanging information, not for a system of inference. What don't you get from XML and XML Schema? Or XQuery. (XML Schema is *a* type theory, so perhaps it's not sufficiently flexible (though, I think it's pretty expressive what with regex types. But it could be augmented.) Cheers, Bijan Parsia..
Received on Friday, 1 July 2005 06:09:33 UTC