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Re: OWL2 questions

From: Thomas Loertsch <loertsch.thomas@guj.de>
Date: Tue, 12 May 2009 15:28:00 +0200
To: Alan Ruttenberg <alanruttenberg@gmail.com>
CC: public-owl-dev <public-owl-dev@w3.org>
Message-ID: <C62F4600.125C%loertsch.thomas@guj.de>
hi alan,

thanks a lot for your detailed response! you've cleared up quite a few of my
misconceptions :-) (although i fear there are more to come)

a few remarks:

On 10.05.09 06:08, "Alan Ruttenberg" <alanruttenberg@gmail.com> wrote:

> On Tue, May 5, 2009 at 9:21 AM, Thomas Loertsch <loertsch.thomas@guj.de>
> wrote:
>> the full draft of the mapping can be found at http://purl.org/amicroformat
> 
> This url doesn't resolve - you need to have a trailing "/"

oups...

> - There is no owl2 namespace, just owl.

i wonder though how i make it clear to a reader/parser/reasoner, that i'm
using constructs that are only defined in OWL2?
 
> If you can define a regular expression that matches html
> ;-) , you could define an html type by create a datatype restriction
> on xsd:string with a pattern facet.

i'll try that. since i only have to check for some html-tags it seems
reasonable

> 2) comment on the range axiom
 
> :method
>       rdf:type owl:DatatypeProperty ;
>       rdfs:comment "The method of the recipe." ;
>       rdfs:domain :recipe ;
>       rdfs:range _:b1 ;
>       rdfs:isDefinedBy <http://microformats.org/wiki/hrecipe#method> .
> 
> _:b1  rdf:type rdfs:Datatype ;
>       owl:unionOf (xsd:string <http://www.w3.org/TR/html/>) .
> 
> []    rdf:type owl:axiom ;
>       rdfs:comment "The field MAY include valid HTML markup e.g.
> paragraphs or a list for steps in the method." ;
>       owl:subject :method .
>       owl:predicate rdfs:domain ;
>       owl:object _:b1 ;

that sounds right to me. of course reification is always a little worrying.

> - One doesn't use owl:Restriction in this place - it is used in
> certain class expressions, rather than in asserting a range or domain.
> However, it is the case that DataPropertyRange( DPE DR ) means the same
> thing as SubClassOf( owl:Thing DataAllValuesFrom( DPE DR ) ), and in
> that case one would use owl:Restriction.
 
> owl:Thing
>       rdfs:subClassOf
>               [ rdf:type owl:Restriction ;
>                 owl:allValuesFrom
>                         [ rdf:type rdfs:Datatype ;
>                           owl:unionOf (xsd:string
> <http://www.w3.org/TR/html/>)
>                         ] ;
>                 owl:onProperty :method
>               ] .
> 
> :method
>       rdf:type owl:DatatypeProperty ;
>       rdfs:comment "The method of the recipe." ,
>          "The field MAY include valid HTML markup e.g. paragraphs or a
> list for steps in the method." ;
>       rdfs:domain :recipe ;
>       rdfs:isDefinedBy <http://microformats.org/wiki/hrecipe#method> .

if i understand this correctly it says: "whenever something is in the range
of :method, it is constrained this way". but the connection from the :method
property to this restrictrion seems very brittle. how would i get aware of
it in "real life"? wouldn't it need very involved sparqling to find it?

> I will look in to the next example and try to respond later.

don't! you answered that already
 
> Note that OWL 2 is currently in last call. If you read these documents
> and have comments, please send them to public-owl-comments@w3.org by
> May 13, 2009.

yep, will do.

thanks again!
thomas


.
Thomas Lörtsch
Business Development
G+J Exclusive&Living digital GmbH
Redaktion Online
..
Stubbenhuk 5
20459 Hamburg
...
eMail: loertsch.thomas@guj.de
Received on Tuesday, 12 May 2009 13:28:56 GMT

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