W3C home > Mailing lists > Public > public-owl-dev@w3.org > July to September 2007

RE: declaredAs

From: John McClure <jmcclure@hypergrove.com>
Date: Thu, 9 Aug 2007 10:56:36 -0700
To: "Pat Hayes" <phayes@ihmc.us>, "Michael Schneider" <m_schnei@gmx.de>
Cc: <public-owl-dev@w3.org>, <bmotik@cs.man.ac.uk>, <bparsia@cs.man.ac.uk>
Message-ID: <MGEEIEEKKOMOLNHJAHMKMEIFEFAA.jmcclure@hypergrove.com>

Sorry to interrupt this fascinating conversation but I have a related
question... if I can speak in XML for a moment...

Are not assertions indicated by rdf:about, and declarations by rdf:ID? I have
the understanding that the 'best practice' trend has been to make all statements
to be rdf:about some subject, with an rdf:ID declaration of the subject treated
as, if you will, a virtual axiom.  Given this, I don't understand the need for a
new predicate that distinguishes between assertive & declarative axioms.

<Class rdf:about='yourClass'/>	<!-- an assertion -->
<Class rdf:ID='myClass'>		<!-- a declaration-->
  <subClassOf rdf:resource='yourClass'/>

I don't know how to express this distinction in the triples syntax so common to
the postings...

Thanks for your insights Pat, Michael, Bijan et al. !

>-----Original Message-----
>From: public-owl-dev-request@w3.org
>[mailto:public-owl-dev-request@w3.org]On Behalf Of Pat Hayes
>Sent: Thursday, August 09, 2007 9:04 AM
>To: Michael Schneider
>Cc: public-owl-dev@w3.org; bmotik@cs.man.ac.uk; bparsia@cs.man.ac.uk
>Subject: Re: declaredAs
>>Hi Pat!
>Hi Michael
>>In another answer to Bijan Parsia, Pat Hayes wrote:
>>>  I guess what I don't see is why these have to be syntactically
>>>  distinct from assertions, though. After all, we have here a language
>>>  whose business is saying that things belong in classes. And what we
>>>  want to say here is... well, you get the point. Why not just have a
>>>  special class of classes called "isADeclarationClass", which when
>>>  asserted of a class means that saying that something is in that class
>>>  is a declaration. Then your declaration classes can be my ordinary
>>>  classes, which gives us a lot of flexibility, and avoids a kind of
>>>  global ossification into a single built-in hierarchy.
>>Hm, not sure if I really understand this idea. If I correctly
>>understand you than 'isADeclarationClass' would be a specialization
>>of owl:Class, i.e.
>>    owl:isADeclarationClass ISA owl:Class
>>And an axiom like
>>    my:C a owl:IsADeclarationClass
>>would then be a substitute for otherwise declaring
>>    my:C owl:declaredAs owl:Class
>>Is this right?
>>But why then not just directly saying
>>    my:C a owl:Class
>Because this is merely an assertion, whereas the (same) assertion
>involving a declarationClass would have the force of a declaration.
>In particular, any inconsistency involving the declarationClass class
>would be posted as a syntax error rather than a simple inconsistency.
>IHMC		(850)434 8903 or (650)494 3973   home
>40 South Alcaniz St.	(850)202 4416   office
>Pensacola			(850)202 4440   fax
>FL 32502			(850)291 0667    cell
>phayesAT-SIGNihmc.us       http://www.ihmc.us/users/phayes
Received on Thursday, 9 August 2007 17:56:26 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 20:58:15 UTC