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RE: [Fwd: RE: LANG: compliance levels]

From: Ziv Hellman <ziv@unicorn.com>
Date: Sun, 28 Apr 2002 16:59:25 +0300
Message-ID: <6194CD944604E94EB76F9A1A6D0EDD233AD2B6@calvin.unicorn.co.il>
To: "Deborah McGuinness" <dlm@ksl.stanford.edu>, <www-webont-wg@w3.org>


>-----Original Message-----
>From: Deborah McGuinness [mailto:dlm@ksl.stanford.edu]
>Sent: Sunday, 28 April, 2002 2:37
>To: www-webont-wg@w3.org
>Subject: Re: [Fwd: RE: LANG: compliance levels]
>
>
>>>
>> 1) Please provide more detail as to exactly what you intend 
>by stating
>> 'functionality of properties'
>>
>
>functionality of roles in our proposal is equivalent to 
>stating   an at most 1 restriction.
>(thus the role has either 0 or 1 filler but no more).
>It also abides by the same side condition as exists in 
>DAML+OIL - ie., it is not allowed to state that a role is 
>simultaneously functional AND transitive.

OK, understood

>
>>
>> 2) As recent email exchanges on the WebOnt forum indicate, the
>> distinction between primitive and defined classes can be tenuous, at
>> least with full DAML+OIL expressiveness. Will the same be true of
>> compliance level 1 of OWL?
>
>I guess I need more detail on the tenuous nature of 
>defined/primitive distinction in order to address this question.
>I think we do not have a choice in daml+oil/owl/fowl but to 
>solve the issue of grouping statements somehow and thus will 
>have a mechanism for grouping an entire term definition 
>together thus solving the problem of potentially having 
>sufficiency conditions for membership in multiple places in a 
>knowledge base.  If this problem is solved, do you still have 
>other problems with the primitive/defined class
>distinction?

As I understood matters, the problem with primitive vs defined classes
does indeed revolve around whether a class has associated with it
sufficiency conditions for inferring instance membership. If statement
grouping were strictly enforced to prevent the possibility of
sufficiency conditions ever appearing other than in the location in
which the original class definition is made, then this problem could be
overcome, but the price might be too high. In Web and distributed pages
contexts, the flexibility to refer in one document to a class defined in
another document somewhere else, and perhaps add new
conditions/definitions would seem to be of high importance. Strict local
grouping of definitions would run counter to this Web ambition.



>
Received on Sunday, 28 April 2002 10:00:17 GMT

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