- From: Ian Horrocks <horrocks@cs.man.ac.uk>
- Date: Wed, 20 Jun 2001 22:36:49 +0100 (BST)
- To: Jim Hendler <jhendler@darpa.mil>
- Cc: "Geoff Chappell" <geoff@sover.net>, <www-rdf-logic@w3.org>
On June 17, Jim Hendler writes: > At 11:04 PM +0100 6/17/01, Ian Horrocks wrote: > >On June 17, Geoff Chappell writes: > >> Hi folks, > >> > >> I've been working with expressing inference rules in daml and need > >>a little help/feedback. > >> > >> It seems that rules with just the subject unbound can be expressed easily. > >> > >> For example the rule: > >> type(X,animal)<-type(X,dog) > >> can be expressed as: > >> type(X,animal) or not(type(X,dog)) > >> or in daml: > > > >It seems to me that all you are saying here is that dog is a subClassOf > >animal. What is wrong with > > > ><daml:Class rdf:ID="dog"> > > <rdfs:subClassOf rdf:resource="#animal"/> > ></daml:Class> > > > >Am I missing something? > > > >Ian > > Ian- > You and Jeff Heflin had a discussion at one point about what sorts > of SHOE [1] rules could and couldn't be expressed in DAML. Did that > ever get written down? Seems like it would be useful in helping > Geoff (who later wrote) We didn't ever write it down. I'm not sure that we came to any startling conclusion, but I will speak to Jeff and see if we think we can come up with some notes that would help Geoff and others with similar requirements. > > At 4:42 PM -0400 6/17/01, Geoff Chappell wrote: > > > >Thanks for the response, but... I guess I need to be careful about my > >(over)use of adverbs -- "ultimately" I'm not trying to express anything > >about dogs or animals necessarily but to translate inference rules of all > >(or some) types into daml terms (if possible). My example was a bad one > >because there are so many ways without explicit inference to get the point > >across (as you've demonstrated). > > My recollection is that DAML can do many things, but there are many > rules one might wish to express that aren't easily done in DAML This is certainly true. > Have a good reference on this? Not that I can think of. Comparing the expressive powers of different logics is notoriously difficult. Regards, Ian
Received on Wednesday, 20 June 2001 17:58:45 UTC