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Re: declaredAs

From: Pat Hayes <phayes@ihmc.us>
Date: Thu, 9 Aug 2007 11:04:19 -0500
Message-Id: <p0623090ec2e0eace10fa@[10.100.0.67]>
To: "Michael Schneider" <m_schnei@gmx.de>
Cc: public-owl-dev@w3.org, bmotik@cs.man.ac.uk, bparsia@cs.man.ac.uk

>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?

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.

Pat
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Received on Thursday, 9 August 2007 16:04:37 GMT

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