Re: what are the best primitives for RDF/OWL?

No.  The idea that X and Y are equivalent, but not sameAs,
means that the context of X and Y are different.
I think the most meaningful cases will involve classes whose
instances change over time.

Think of it this way.  The context of X, denoted by Cx, can
be viewed as a hierarchy, with X having a place in Cx which
is determined by its definition.  Ditto for Cy and definition of Y.
Now we discover that  Cx:X  equivalentClass  Cy:Y, even
though they have different definitions.
But they may not be equivalent tomorrow.
Or, we may discover that there are cause-effect reasons for
the equivalence, and eventually conclude that Cx:X  sameAs  Cy:Y

The morning-star, evening-star example is similar to this.

I think the example in the OWL document is a bad one.
I would say   Car  owl:sameAs  Automobile

Dick
----- Original Message ----- 
From: "Ignazio Palmisano" <ignazio.palmisano@gmail.com>
To: "Semantic Web at W3C" <semantic-web@w3.org>
Sent: Thursday, July 10, 2008 6:20 AM
Subject: Re: what are the best primitives for RDF/OWL?


>
> Richard H. McCullough wrote:
>>
>> I'd like to modify the focus of "deprecated URIs" a little bit,
>> and summarize some of the discussion on this list in 2003 time frame.
>>
>> First topic: SubClassOf vs. properSubClassOf.
>> By definition,  X  SubClassOf  Y has two possible meanings.
>> 1)  X  sameAs Y
>> 2)  X  properSubClassOf  Y
>> Although meaning (1) may seem to have nice mathematical properties,
>> I think it's harmful to always have to "dispose" of that possibility when
>> reasoning about classes.
>
> Why use sameAs in this context? It is more appropriate to use 
> owl:equivalentClass, whose function is exactly that (at least in my 
> reading of 
> http://www.w3.org/TR/2004/REC-owl-features-20040210/#equivalentClass).
>
> I.
>
>
>
Dick McCullough
http://mKRmKE.org/
Ayn Rand do speak od mKR done;
knowledge := man do identify od existent done;
knowledge haspart proposition list;
mKE do enhance od "Real Intelligence" done;

Received on Thursday, 10 July 2008 15:15:02 UTC