[Om] Adding DLMF links to CDs [Re: How to translate csymbol/@definitionURL]

[Urs Holzer]

Hi James, Christoph and other readers on the mailinglist

Christoph LANGE wrote:
> No, it's a very good objection.  I cannot tell you what implications
> it has to link two URIs with relation1#eq, but I can tell you what
> it means to an OWL reasoner when you use owl#sameAs (see
> http://events.linkeddata.org/ldow2010/papers/ldow2010_paper09.pdf for
> further background).  Please allow me a short excursion into OWL and
> OWL/RDF-based linked data here:
> 
> [...]
> 
> That means, <http://dlmf.nist.gov/4.14.E1> _is_ transc1#sin, with all
> of its properties.  [...]
> 
> So much for the strict semantics of that.  You may now think that
> owl:sameAs is a bit too strong for us, but linked data practice
> (e.g. the application that I showed at the workshop) is more relaxed
> than OWL theory.  And there is not a big choice of link types that
> are universally understood by linked data clients.  The only
> alternative would be rdfs:seeAlso, which is IMHO too weak for what
> we want to say here, or an OpenMath-specific subrelation of
> rdfs:seeAlso (e.g. om:equivalentDefinition), but the average client
> will either ignore such links (i.e. not follow them), or treat them
> in the same way as rdfs:seeAlso.
> 
> So I'd still opt for owl:sameAs (unless we want relation1#eq).

One other thing that strikes me here: in linked data practice one often 
makes a distinction between a resuource and its description. (Is this 
correct, Christoph?) So, It hink that <http://dlmf.nist.gov/4.14.E1> is 
a description of a resource 'sin', not the 'sin' itself. (Or does DLMF 
say that <http://dlmf.nist.gov/4.14.E1> is the resource and 
<http://dlmf.nist.gov/4.14#E1> is the description?) If I am right, using 
owl:sameAs might cause trouble. For example, 
<http://dlmf.nist.gov/4.14.E1> might have an author:

  <http://dlmf.nist.gov/4.14.E1> dc:author "Levinson" .

This would then cause the 'sin' itself to have Levinson as author which 
is kind of weird. In general, I think one has to be extremely careful 
when using owl:sameAs. I opt for not using owl:sameAs and not using 
relation1#eq either. Is there another option which would be reasonable 
in practice?

Maybe it would be correct to state that <http://dlmf.nist.gov/4.14.E1> 
_defines_ 'sin' instead of saying that they are the same.

Greetings
Urs