- From: pat hayes <phayes@ai.uwf.edu>
- Date: Sat, 23 Jun 2001 23:22:15 -0500
- To: jos.deroo.jd@belgium.agfa.com
- Cc: w3c-rdfcore-wg@w3.org
> >>>>I think/hack that both anonymous *terms* can be *unified* > >>>>which is NOT the same as equality > >>> > >>> Then your hack only seems to works when we can unify anonymous > >>> terms, or they have some sort of UniqueProperty attached. How do > >>> we solve the general case? > >> > >>There was some related discussion in the telecon > >>this afternoon, and I was kind of unable to explain > >>my point...(I'm really hopeless in that respect) > >> > >>The thing about anonymous nodes is that they > >>are ***variables*** > >>if they would be constants, we would be able > >>to identify them with ***URI constants*** > >>Now they are actually existentially quantified > >>variables, something like: there exists an _:a > >>or (using existing vocab): this log:forSome _:a > >>So I think we should say that *explicitly* > >>is the testresults (and in the model theory) > >>(the general case?) > > > >Well, logically they seem to be like existentially quantified > >variables, yes. But you CANT unify distinct existentially quantified > >variables (validly) ! They would be distinct skolem constants, which > >do not unify in general. (They do if they are existential variables > >bound by the same quantifier, but then they would be the same skolem > >constant :-) > >I agree that you CANT unify distinct existentially quantified >variables in the sense that one does with universally >quantified variables i.e. computing a MGU (Most General Unifier) >but what we actually compute is a LCU (Least Common Unifier) Whoa! Ive never heard that term before. Can you specify what you mean? Eg give a sketch of this LCU algorithm, or some explanatory examples? >for those anonymous nodes (I mean what those nodes have in >common w.r.t. their descriptions and taking into account >daml:UniqueProperty properties to succeed/fail) Sorry, that isn't enough for me to reconstruct what you mean. >, and that >seems to work in a logical sense but I'm also wondering why?-) I will try to explain once I know what you mean. 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 Monday, 25 June 2001 10:42:51 UTC