W3C home > Mailing lists > Public > www-webont-wg@w3.org > April 2002

Re: SEM: Face-to-Face version of approaches document

From: Pat Hayes <phayes@ai.uwf.edu>
Date: Mon, 8 Apr 2002 03:20:10 -0400
Message-Id: <p05101509b8d62b3a2243@[65.217.30.94]>
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 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:57:49 GMT