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Issue timbl-03 "collection clutter" proposal to close

From: Dave Beckett <dave.beckett@bristol.ac.uk>
Date: Thu, 24 Apr 2003 11:01:19 +0100
To: w3c-rdfcore-wg@w3.org
Message-ID: <32016.1051178479@hoth.ilrt.bris.ac.uk>


Summary: reject

The comment raised in
http://lists.w3.org/Archives/Public/www-rdf-comments/2003JanMar/0586.html

[[
  I believe that in 7.2.19 Production parseTypeCollectionPropertyElt
    the wording

  """For each event nin s, the following statement is added to the graph:

  n.string-value <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> 
  <http://www.w3.org/1999/02/22-rdf-syntax-ns#List> .


  """

  adds redundant triples to the graph.
  I believe that waste of time and space at this level in the 
  architecture is unnecessary, and that that wording should be removed 
  (and any other reference to the adding type statements for Lists where 
  a rdf:first is there).

  It is trivial to restore the triples for anyone who wants them fro a 
  graph without them,
  using
{ ?x rdf:first ?y } =>  { ?x  a rdf:List }.
]]


Here is a draft response:

[[
The RDF Core WG has considered your last call comment captured in

   http://www.w3.org/2001/sw/RDFCore/20030123-issues/#timbl-03

(raised in
 http://lists.w3.org/Archives/Public/www-rdf-comments/2003JanMar/0586.html
)

and decided

   URL-HERE

to reject it on the grounds that it is being used by OWL and could
not be added at a higher level since it is closedly tied to an
RDf/XML syntax abbreviation.

This triple is part of the closed collection form added to the RDF
model and RDF/XML syntax for use by OWL based on the DAML+OIL
daml:Collection syntax extension to RDF/XML. 

The reason this could not be added at the OWL level is that it is
generated by the rdf:parseType="Collection" syntax which is in the
RDF/XML specification.  There is no "hook" to allow optional adding
of <x> rdf:type rdf:List for the generated notes.

rdf:List is refered to in several places throughtout the proposed OWL
language and seems to have good uses:


Example of using rdf:List explicitly for collection of datatyped literals
  http://www.w3.org/TR/2003/WD-owl-ref-20030331/#EnumeratedDatatype

As the range of these three properties:
  owl:distinctMembers
  owl:intersectionOf
  owl:oneOf
  owl:unionOf

See the RDF Schema of OWL http://www.w3.org/TR/2003/WD-owl-ref-20030331/#appB

typically used in the examples with rdf:parseType="Collection" form:
  http://www.w3.org/TR/owl-guide/#EnumeratedClasses
  http://www.w3.org/TR/owl-guide/#DisjointClasses


Used in OWL Semantics and Abstract Syntax WD, 31 March 2003

  Translation to RDF Graphs
  http://www.w3.org/TR/2003/WD-owl-semantics-20030331/semantics-all.html#4.1

  5 RDF-Compatible Model-Theoretic Semantics
    5.2. OWL Interpretations
  http://www.w3.org/TR/2003/WD-owl-semantics-20030331/semantics-all.html#rdf_List_rdf

    if E is             then                          Note
             SI(E)..  CEXTI(SI(E))=   and

    rdf:List            IL           IL subsetof RI  This defines IL as
                                                     the set of OWL lists. 

So it is needed to define OWL lists.


  A.1 Correspondence for Descriptions (Informative)
    Used in the proof for Lemmas 1, 4

  A.2 Correspondence between OWL DL and OWL Full (Informative)
    Used in the proof-sketch for Lemma 5

]]


Dave
Received on Thursday, 24 April 2003 06:03:20 EDT

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