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Re: ISSUE-3: REPORTED: Lack of anonymous individuals

From: Ian Horrocks <ian.horrocks@comlab.ox.ac.uk>
Date: Sat, 10 Nov 2007 12:51:49 +0000
Message-Id: <B9B1A78F-AFBA-4D5E-8F40-C902595755CB@comlab.ox.ac.uk>
Cc: public-owl-wg@w3.org
To: Jeremy Carroll <jjc@hpl.hp.com>

This seems a reasonable compromise to me.

In fact ISSUE-3 is relatively trivial, because we can already capture  
OWL 1.0 style "tree like" cases using class assertions with nominals.  
E.g., we can assert that Dave is a friend of a friend of John using a  
subClass axiom:

subClassOf(
	ObjectOneOf(Dave)
	ObjectSomeValuesFrom(isFriendOf ObjectSomeValuesFrom(isFriendOf  
ObjectOneOf(John))))

The intervening "anonymous" friend has the existential semantics.

Ian


On 9 Nov 2007, at 14:09, Jeremy Carroll wrote:

>
>
> Somewhere in the midsts of this thread ...
>
> Boris wrote:
> [[
> Imagine you have an ABox A containing the following assertions:
>
> (1)  hor(_:1,_:2)
> (2)  ver(_:2,_:3)
> (3)  ver(_:1,_:4)
> (4)  hor(_:4,_:5)
> (5)  _:3 != _:5
>
> ]]
> etc.
>
> I find the message compelling.
>
> As one of the RFC Core WG who originally raised our ISSUE-46, I  
> would be satisfied with allowing anonymous individuals in the tree  
> like fashion (ISSUE-3) and disallowing them in the general position  
> (ISSUE-46).
>
> Personally, I have enough information to be able to vote for  
> closing both issues as above.
>
> I haven't thought through your alternative of skolemized semantics  
> throughout ... my gut feel is negative.
>
> Given that ISSUE 46 was originally raised by RDF Core, I would  
> suggest passing any proposal to close it, and a rationale (e.g.  
> Boris's message) in front of Pat Hayes - and assuming he is happy,  
> notifying semantic web interest, noting that I and Pat, are  
> satisfied would close the procedural loop. Both of these could be  
> done as an action after a decision to close the issue - with the  
> issue in a pending-close state for a short time.
>
> Jeremy
>
>
Received on Saturday, 10 November 2007 12:52:08 GMT

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