Re: comment: Representing Classes as Property Values

Dear Denny,

Thank you for the interesting idea. In fact, it will work if you use 
the two namespaces "in parallel", without taking them together: either 
anitops or anitxes (you don't name it, but this is the last thing in 
your email -- imports anitax and adds the last few statements)

However, once you try to import both, anitaxes and anitops into your 
application, you are in OWL Full. The former makes Lion, etc into 
classes, and then you have the same problems as with approach 1 in the 
note. So, it doesn't seem to me that the trick works, unfortunately :( 
You just can't have your Lion as both a class and an individual in OWL 
Lite... alas...

Or have I misinterpreted what you were suggesting?

On Oct 20, 2004, at 8:09 AM, Denny Vrandecic wrote:

> Hello all,
> in this mail I am considering an alternative solution to the problem 
> addressed in the W3C Working Draft „Representing Classes as Property 
> Values“ [1]. It is just an idea, and I hope you won't tie me up and 
> burn me for it being so boringly and obviously wrong, but instead 
> correcting me and telling me what's wrong about it.
> I like staying in OWL Lite, and I – being a programmer and thus being 
> lazy – don't want to program anything twice. Still, I prefer intuitive 
> ways, because they will probably be easiest to adopt by the user. 
> Further on, I want to use some approach without extra instances 
> caretaking, without the need to keep two ontologies consistent, 
> without unclean modeling. So I can't use approach 1 (it doesn't remain 
> in OWL Lite or OWL DL), approach 2 (LionSubject is not an instance of 
> the class Animal, which would be inferred by approach 2), approach 3 
> (although it offers clean modeling, there is a lot of caretaking 
> needed for consistency reasons), approach 4 (instance caretaking) nor 
> approach 5 (no semantics defined for annotations).
> Yeah, you know all the problems and list them already. I want to 
> suggest yet another approach, which combines some ideas of the above 
> approaches. I will stick to the given example.
> First model your animals taxonomy as you always would, just with one 
> little twist: don't use the rdfs:subclassOf-relation, but another one 
> you define here (call it whatever you like, for the example I will 
> take :subsumes).
> :Category
> :subsumes
> 	a			rdfs:Property
> :Animal
> 	a			:Category
> :Lion
> 	:subsumes		:Animal
> :AfricanLion
> 	:subsumes		:Lion
> This is your actual taxonomy, that defines the hierarchy. You would 
> like to use it as a class hierarchy and you would like to use it as a 
> topic hierarchy, but due to the OWL DL constraints, you can't. Or can 
> you?
> Let's name the document above, namespace 
> anitop. Now, for us to be able to use it as a topic hierarchy, we will 
> make a second document, basically being:
> :Topic
> 	a			owl:Class
> anitop:Category
> 	owl:equivalentClass	:Topic
> :subTopicOf
> 	a			owl:TransitiveProperty
> 	rdfs:domain		:Topic
> 	rdfs:range		:Topic
> anitop:subsumes
> 	owl:equivalentProperty	:subTopicOf
> And it has to owl:imports anitop. Let's call this 
>, ns anitops.
> This way we can use anitop:Lion, anitop:AfricanLion and so on as 
> property values, as they are mere instances of anitops:Topic (this is 
> inferred by the properties domain and range specification).
> Now we make another URI,, namespace anitax, that 
> it actually just a redirect to (I guess, the 
> other way is more intuitive, but this depends on your philosophical 
> commitment).
> We now make a final document, that offers:
> anitax:Category
> 	 rdfs:subClassOf	owl:Class
> anitax:subsumes
> 	owl:equivalentProperty	rdfs:subClassOf
> This time anitax gets imported. Now we can make a certain lion being 
> an instance of anitax:Lion, and the book having the topic anitop:Lion. 
> Both times the initally defined hierarchy gets used.
> Looking forward to your comments.
> Best regards,
> Denny
> [1]
> -- 
> Denny Vrandecic
> Institute AIFB, University of Karlsruhe (TH)
> phone: +49 (0) 721 608 6558

Received on Wednesday, 20 October 2004 20:59:28 UTC