Re: OWL "Sydney Syntax", structured english

On Wed, 2006-11-29 at 20:26 +0100, Kaarel Kaljurand wrote:
> Hello,
> 
> On 11/29/06, Dan Connolly <connolly@w3.org> wrote:
> >
> > In the RoleNoun pattern, the verb is a generic/implicit 'has';
> > rather than
> >
> >   Dan knows Pat.
> >
> > we write
> >
> >   Dan has acquaintance Pat.
> >
> > In N3, we allow the 'has' to be left out:
> >
> >   Dan acquaintance Pat.
> 
> How does this pattern work with negation (and other OWL features)?
>
> Dan no acquaintance Pat?

The RoleNoun pattern has no particular support for negation
or other OWL features. I just use the OWL vocabulary
like any other RDF vocabulary.

While OWL is closed under negation, negating one triple like
that is so complicated that I'm not sure I remember how to do it.
The straightforward way to express negation with OWL uses
classes; e.g. 

  Carnivore owl:complementOf Vegetarian.
  Dan rdf:type Carnivore.

N3 has syntactic sugar for rdf:type that lets us write:

  Dan a Carnivore.

and it has [] syntax for bnodes, so I can write:

  Dan a [ owl:complementOf Vegetarian ].

to say "Dan is not a vegetarian".

Back to "Dan doesn't know Pat", I think the class
of things that know Pat is

 ThingsThatKnowPat owl:onProperty acquaintance; owl:hasValue Pat.

and as above, its complement is [ owl:complementOf ThingsThatKnowPat ]
so we'd write

  Dan a [ owl:complementOf ThingsThatKnowPat ].

or:

  Dan a [ owl:complementOf [ owl:onProperty acquaintance;
                             owl:hasValue Pat ] ].

I think I got that right, but I'd need to run it thru cwm or SWOOP
or something to be sure.

p.s. I'm also implicitly using the @keywords shortcut of N3
to leave out many of the colons; details are in the N3 tutorial
  http://www.w3.org/2000/10/swap/doc/Shortcuts

If you're new to N3, the primer is the 1st part of the tutorial;
it's sort of the one-page introduction.
 http://www.w3.org/2000/10/swap/Primer


-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
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