Re: OWL2 questions

by tl_guj :: Rate this Message:

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@...> wrote:

> On Tue, May 5, 2009 at 9:21 AM, Thomas Loertsch <loertsch.thomas@...>
> 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@... 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@...

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