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Re: Inverse property on classes

From: Cédric Thiébault <cedric.thiebault@gmail.com>
Date: Thu, 14 May 2009 18:27:26 -0400
Message-ID: <9144d19b0905141527j62025a7bpcb5e15f1350d9633@mail.gmail.com>
To: Pavel Klinov <klinovp@cs.man.ac.uk>
Cc: public-owl-dev@w3.org
Thanks for your help Pavel :)
So even if I use cardinality, it won't be different?
:Pizza_mozzarella_class :hasTopping exactly 1 :Mozzarella_class

Would you use allValuesFrom<http://www.w3.org/TR/owl-guide/#owl_allValuesFrom>
to
create this weird pizza class that has all mozzarella as topping?
:Pizza_mozzarella_class :hasTopping all :Mozzarella_class

Actually, I want to use classes and not individuals because I need to reason
on them and it seems that reasoners can only work on classes... But it is a
lot simpler to  work with properties between instances (at least if we want
to use inverse and transitive properties) than between classes.

Regards,

Cedric


On Wed, May 13, 2009 at 4:40 PM, Pavel Klinov <klinovp@cs.man.ac.uk> wrote:

> Hello,
>
> Cédric Thiébault wrote:
>
>> Hi,
>>
>>
> [snip]
>
>
>>
>> When I create an individual :Pizza_mozzarella and add a property
>> :hasTopping on :Mozzarella individual, I can work with the inverse property
>> on the topping and I see that :Mozzarella :isToppingOf :Pizza_mozzarella. It
>> works great with individual.
>>
>> But when I try to do the same test with classes:
>> :Pizza_mozzarella_class :hasTopping some :Mozzarella_class
>>
>> But I cannot use the inverse property: :Mozzarella_class does not know
>> anything about :Pizza_mozzarella_class.
>>
>> Is this normal ?
>>
>
> Yes. Notice that you are not making any claim here about Mozzarella_class
> in general. You're only saying that all instances of Pizza_mozzarella_class
> are related to *some* instance of Mozzarella_class. Imagine a model in which
> there are 10,000 mozarrellas and only one of them is used as a topping on
> all pizzas (it would be a satisfying model). Would you want to be able to
> conclude something general about 9,999 mozarellas basing on only one
> instance?
>
>  Are inverse properties usable only on individuals ?
>>
>
> Well, it depends on what you mean by "using". For example, you can define a
> class (and an instance) of pizzas which has *all* instances of Mozzarella as
> toppings (although it's not that trivial). Then, of course, you'll be able
> to infer that :Mozzarella_class :isToppingOf some :that_weird_pizza_class.
>
>
> Cheers,
> Pavel
>
>
>
>> Thanks for your help :-)
>>
>> Cedric
>>
>>
>>
>
Received on Thursday, 14 May 2009 22:28:08 GMT

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