- From: pat hayes <phayes@ai.uwf.edu>
- Date: Mon, 16 Dec 2002 11:15:30 -0600
- To: Graham Klyne <GK@NineByNine.org>
- Cc: w3c-rdfcore-wg@w3.org
>Concerning: http://www.coginst.uwf.edu/~phayes/RDF_Semantics_finalCall_2.html > >At 03:12 PM 12/15/02 -0600, pat hayes wrote: >>Datatype clashes are the only inconsistencies recognized by this >>model theory. The definition of entailment means that a >>D-inconsistent graph D-entails any RDF graph; however, it will >>usually not be appropriate to consider such 'trivial' entailments >>as useful consequences, since they are not valid rdf- or rdfs- >>entailments. > >I'm puzzled by the use of "inconsistency" here .. my understanding >is that technically, the concept of consistency depends on negation, >which is not recognized in RDF. > >[From Metalogic, Geoffrey Hunter: >"A system S is Simply Consistent iff for no formula A of S are both >A and the negation of A theorems of S." He then goes on to define >absolute consistency for systems with the possibility to express >negation of any formula.] > >My take on this had been that a D-inconsistent graph is unsatisfiable. > >Ah, I see you're using a different definition of inconsistency >(http://www.coginst.uwf.edu/~phayes/RDF_Semantics_finalCall_2.html#glossInconsistent). >So my comment becomes simply: your definition of inconsistency >seems to be, er, "inconsistent" with some other published >definitions. Well, not *inconsistent* with. My own usage is that 'inconsistent' refers to any unsatisfiable syntactic condition, not just those involving negation. Description-logic frameworks can become unsatisfiable in other ways than having (P and notP ) derivable, since they aren't necessarily deductively complete. But perhaps it would have been better to have used 'unsatisfiable'. I'll take that as a last-call fix before final pub, OK? Pat -- --------------------------------------------------------------------- IHMC (850)434 8903 home 40 South Alcaniz St. (850)202 4416 office Pensacola (850)202 4440 fax FL 32501 (850)291 0667 cell phayes@ai.uwf.edu http://www.coginst.uwf.edu/~phayes s.pam@ai.uwf.edu for spam
Received on Monday, 16 December 2002 12:15:35 UTC