- From: Pat Hayes <phayes@ai.uwf.edu>
- Date: Mon, 8 Apr 2002 03:20:10 -0400
- To: Jeff Heflin <heflin@cse.lehigh.edu>
- Cc: www-webont-wg@w3.org
> >6) I'm not sure about this one. I am leaning in favor of it, because it >appears to me to be simple entailment. If we translate this into FOL >with unary classes for predicates, then this seems to say that: > >Student(john) >Employee(john) > >entails > >Student(john) AND Employee(john) > >I can't see how we could have a semantics that doesn't say that. But >since Pat Hayes is arguing against this, and he is more of a logic >expert than I could ever hope (or want ;-) ) to be, I must be missing >something here. Just to clarify. Im not arguing against the inference, obviously. Im arguing against the claim that the only way to justify this inference is by asserting that a class (an intersection) *exists*. As Jeff says, if we translate it into logic, the inference is obvious, and (I would add) doesn't require reasoning about the existence of sets, or the inclusion of any sets in the domain of discourse. Its often called &-introduction, and its probably the simplest inference rule ever stated, except possibly the duplication rule in linear logic (infer P from P). Maybe we should just translate all this stuff into logic and see what we get; it would almost certainly be simpler than what we have right now. After all, it *is* logic really, as everyone knows, right? I mean, nobody here thinks that DLs and frame languages are fundamentally *different* from logic, do they? They are just ways of protecting the innocent from the sight of naked quantifiers, right? Pat -- --------------------------------------------------------------------- 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, 15 April 2002 10:57:39 UTC