Re: All humans love (all) cats

On Sat, Oct 2, 2010 at 3:27 PM, Cristian Cocos <cristi@ieee.org> wrote:
>
>> SubObjectPropertyOf( ObjectPropertyChain( ex:pHuman owl:topObjectProperty
>> ex:pCat ) ex:love)
>
> "Loves" would now be a sub-relation of the composite "pHuman o ThingxThing o
> pCat," is that so?

It is a *super* relation of the chain. The whole idea is to connect an
*arbitrary* human to an *arbitrary* cat by some, possible composite,
role (which in this case is "pHuman o ThingxThing o pCat," and in the
Markus' solution is "pHuman o inverse of pCat"). Once it's done OWL 2
allows you to say that such a chain implies role you need (in this
case "loves").

>
> It certainly makes sense, though I feel rather miffed by the fact that such
> a simple and mundane-looking FOL statement requires such an excruciatingly
> complicated workaround in order to be represented in OWL2.

I'll leave it to others to comment on :)

>Would I not run
> into problems with a reasoner such as Pellet, now that I've resorted to this
> type of rendering?

It depends on what you mean by problems. Pellet will certainly handle
it but will have to use an appropriate completion strategy (which may
have an impact of performance but it depends on what else you have in
your KB).

Cheers,
Pavel

>
> Many thanks,
>
> C
>
>
>



-- 
cheers,
--pavel
http://www.cs.man.ac.uk/~klinovp

Received on Saturday, 2 October 2010 15:02:34 UTC