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Re: Semantic E-mail

From: Danny Ayers <danny666@virgilio.it>
Date: Thu, 15 Jul 2004 16:31:59 +0200
Message-ID: <40F6955F.1080302@virgilio.it>
To: Laurian Gridinoc <laurian@gmail.com>
Cc: www-rdf-interest@w3.org, danny@dannyayers.com

Laurian Gridinoc wrote:

>On Thu, 15 Jul 2004 14:01:33 +0200, Danny Ayers <danny666@virgilio.it> wrote:
>  
>
>>>>If the other terms really are equivalent then you could use
>>>>owl:equivalentProperty, but then why bother creating a new term when you
>>>>could use an equivalent?
>>>>        
>>>>
>>>"Property equivalence is not the same as property equality.
>>>Equivalent properties have the same "values" (i.e., the same property
>>>extension), but may have different intensional meaning (i.e., denote
>>>different concepts). Property equality should be expressed with the
>>>owl:sameAs construct. As this requires that properties are treated as
>>>individuals, such axioms are only allowed in OWL Full." [1]
>>>
>>>This is what I'm trying to avoid - OWL Full.
>>>      
>>>
>>Then don't use owl:sameAs.
>>This doesn't prevent you from using an existing equivalent or
>>owl:equivalentProperty.
>>Look at some individuals:
>>
>>{1}
>>m1 filsa:messageid "Message One"
>>m2 filsa:messageid "Message Two"
>>m3 filsa:messageid "Message Three"
>>
>>if you said
>>{2}
>>new:messageId owl:equivalentProperty filsa:messageid
>>
>>then you could infer -
>>{3}
>>m1 new:messageId "Message One"
>>m2 new:messageId "Message Two"
>>m3 new:messageId "Message Three"
>>    
>>
>
>yes,  "Message One" is then a value of `filsa:messageid'; but this
>does not imply that the statement `m1 new:messageId "Message One"'
>have the same meaning as `m1 new:messageId "Message One"'
>  
>

???

>>you could swap it around, so new:messageId was the more general
>>property, but it depends on what the semantics actually are, what you're
>>trying to capture...
>>    
>>
>
>owl:sameAs :)
>  
>

Ok, I don't see the advantage in doing it this way, but fair enough.

>>p1 rdfs:subPropertyOf p2
>>p2 rdfs:subPropertyOf p1
>>
>>the combination expresses equivalence of the properties, and an OWL Full
>>reasoner could get {3} from {1} and vice versa.
>>    
>>
>
>I have thought of this construction, but I'm not sure if it is
>considered logical valid, creating a loop in a hierarchy?
>  
>

Perfectly valid. Remember too that every class is a subclass of itself 
(rdfs10) and every property a subproperty of itself (rdfs6), see also:

http://www.w3.org/TR/rdf-mt/#sinterp

Cheers,
Danny.

-- 

Raw
http://dannyayers.com
Received on Thursday, 15 July 2004 10:35:07 UTC

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