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Re: Latest iteration of RDF Datatyping WD (ship it!)

From: Patrick Stickler <patrick.stickler@nokia.com>
Date: Tue, 16 Apr 2002 12:36:03 +0300
To: ext Jos De_Roo <jos.deroo.jd@belgium.agfa.com>, Pat Hayes <phayes@ai.uwf.edu>
CC: RDF Core <w3c-rdfcore-wg@w3.org>
Message-ID: <B8E1CB33.132F2%patrick.stickler@nokia.com>
On 2002-04-16 11:07, "ext Jos De_Roo" <jos.deroo.jd@belgium.agfa.com> wrote:

> 
> 
>>> this sounds like a union...
>>> and I don't see that as explained in
>>> http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2002Mar/0151.html
>>> and as I still think we should have
>>>   rdfd:range rdfs:subPropertyOf rdfs:range .
>> 
>> I would not recommend that. That would re-introduce all the
>> range-inheritance problems assocaited with datatyping. The basic idea
>> of the current proposal is to keep range-assignment (ie rdfs:Range)
>> and datatyping (rdfd:Range) quite separate, so you can have either
>> one without the other (or both if you choose to). That is the only
>> way I can see to allow the kind of Dublin-Core sloppiness in a
>> rational framework.
> 
> agreed, we currently have something like
> 
> http://www.agfa.com/w3c/euler/rdfd-rules.n3

Right. Though, not meaning to shake things up... ;-)

Rules 2, 3, 5a, and 5b in the above have been removed in
the latest draft and a new rule added (see below).

Rule 3 above follows from the rdfs:range of
rdfd:datatype defined in Rule 0, and thus is
unnecessary.

Rules 2, 5a and 5b have been removed. Both because they
are unnecessary insofar as the datatyping interpretation
is concerned and also because while all three idioms
may all identify the same datatyped literal pairing,
they do not have identical meaning.

It is similar to the well known "morning star" versus
"evening star" example, where both identify the same thing
but do not really have identical meaning. One idiom thus
does not imply another idiom as their total meaning will
not be the same.

The present rules, as defined in the current revision of
the WD are:

--

### rules for RDFD entailment

@prefix log: <http://www.w3.org/2000/10/swap/log#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix rdfd: <http://www.w3.org/2002/rdf-datatyping#> .
@prefix : <rdfd-rules#> .

# :rule0 (same as before)

rdfd:Datatype a rdfs:Class;
   rdfs:subClassOf rdf:Property .

rdfd:datatype a rdf:Property;
   rdfs:domain rdf:Property;
   rdfs:range rdfd:Datatype.

rdfd:lex a rdf:Property;
   rdfs:domain rdfs:Resource;
   rdfs:range rdfs:Literal .

{ 
   :rule1 . 
   ?d a rdfd:Datatype
} 
log:implies 
{ 
   ?d rdfs:domain ?d ;
      rdfs:subPropertyOf rdfd:lex  # added this
} .

{ 
   :rule2 .  # in addition to above, addresses type
             # inferences for blank node values
   ?p rdfd:datatype ?d .
   ?s ?p ?o . 
   ?o rdfd:lex ?l 
} 
log:implies 
{ 
   ?o rdf:type ?d 
} .

--

How do those work? ;-)

Cheers,

Patrick

--
               
Patrick Stickler              Phone: +358 50 483 9453
Senior Research Scientist     Fax:   +358 7180 35409
Nokia Research Center         Email: patrick.stickler@nokia.com
Received on Tuesday, 16 April 2002 05:33:15 EDT

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