[OWL] Limitations on what's told

[Alan Ruttenberg]

Ok. Practically speaking, here is what could be done. NotTold looks  
like InverseFunctional in the abstract syntax, but really is  
syntactic sugar for an annotation property - the translation rules to  
rdf would state that.
That way there is no semantic shadow. The annotation property  
specifically used would be in the owl namespace (is it stated  
anywhere that the owl namespace is reserved for future extensions to  
OWL?).

Implementations would be expected to gag by stating that there was an  
inconsistency - the syntactic form was stated to be disallowed, but  
was used. This is analogous to any other consistency failure.

Does this cause any problems?

-Alan

On Feb 24, 2006, at 6:40 AM, Peter F. Patel-Schneider wrote:

> From: Alan Ruttenberg <alanruttenberg at gmail.com>
> Subject: Re: [OWL] Limitations on what's told
> Date: Fri, 24 Feb 2006 00:37:01 -0500
>
>> On Feb 23, 2006, at 3:41 PM, Peter F. Patel-Schneider wrote:
>>
>>> I believe that all you are asking for is some way to flag  
>>> inappropriate
>>> syntactic constructs, e.g.,
>>>
>>> 	Individual(entity01 type(entity))
>>>
>>> The key here is the "syntactic" above.  I don't favour adding  
>>> semantic
>>> information to flag such constructs.
>>
>> Syntactic is what I think I am aiming for. But I'm not sure what you
>> mean by "adding semantic information to flag such constructs". Do you
>> mean adding a keyword, like InverseFunctional. or NotTold? Could you
>> explain?
>
> You are asking for an addition to the language (the NotTold  
> construct).  I
> assumed that this would go through as some sort of assertion, i.e.,  
> a fact.  I
> suppose, however, that it would be possible that this bit of the  
> language has
> no semantic meaning.  Of course this is not possible in a same- 
> syntax semantic
> extension of RDF (like OWL), but we are already proposing to make  
> OWL 1.1 not
> be a same-syntax semantic extension of RDF.
>
>>> However, I suppose that one could use annotations for this purpose,
>>> i.e.,
>>> annoint a standard "annotation" property that would signal to  
>>> systems
>>> that
>>> particular syntactic constructions are errors.  The annotation would
>>> not, of
>>> course, have any extra semantic force, and many systems would simply
>>> ignore its
>>> "out-of-band" meaning.
>>
>> I think the annotations would be fine. The part of what you say that
>> worries me is the part about systems ignoring them. Either a user can
>> count on a behavior or not. If not then the feature is useless.
>
> Well, there are problems with requiring all systems to "gag" here.   
> How should
> a simple reasoner "gag" if it sees the forbidden situation?
>
>> Or am I misunderstanding you?
>>
>> -Alan
>
> peter