W3C home > Mailing lists > Public > public-owl-dev@w3.org > April to June 2009

Re: Inverse property on classes

From: Pavel Klinov <klinovp@cs.man.ac.uk>
Date: 13 May 2009 21:40:27 +0100
To: Cédric Thiébault <cedric.thiebault@gmail.com>
Cc: public-owl-dev@w3.org
Message-ID: <Prayer.1.0.12.0905132140270.6584@webmail2.cs.man.ac.uk>
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 Wednesday, 13 May 2009 21:19:35 GMT

This archive was generated by hypermail 2.3.1 : Wednesday, 27 March 2013 09:32:57 GMT