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Clarify what it means that the value in a facet-value pair (F v) is an "arbitrary object"

From: Michael Schneider <schneid@fzi.de>
Date: Thu, 8 Jan 2009 10:56:09 +0100
Message-ID: <0EF30CAA69519C4CB91D01481AEA06A0F980B1@judith.fzi.de>
To: <public-owl-comments@w3.org>
Dear WG!

Section 4 of the LC working draft of the Structural Spec makes the following statement w.r.t. facet spaces of datatypes [1]:

     The facet space is a set of pairs of the form < F v >, 
     where F is an IRI called a constraining facet, 
 --> and v is an arbitrary object 
     called a value.

I do not understand the meaning of the phrase "arbitrary object" in this context. 

  (1) Does this mean that arbitrary /literals/ (and nothing else) are allowed, as suggested by the specification of the Direct Semantics of datatype restrictions [2] (only literals are allowed to occur as the values of facets in datatype restrictions)?

  (2) Or does it mean that the value for a facet can be both a /literal OR an individual/, i.e. there may be facets restricting a datatype by something else than a primitive data value? 

I cannot find any definition of the term "object" in the Structural Specification, or any usage of this term from which the meaning in the above statement would become clearer. However, the term "object property" is used throughout the text, and Section 5.6 on "Individuals" [3] makes the following statement: "Individuals represent actual ***objects*** from the domain being modeled.". So "object" in the context of facet-value pairs might easily be misunderstood to exclusively mean "individual", which is certainly not intended.

My suggestion (editorial change request): In the text on facet-value pairs cited above, replace the term "object" by something that clarifies what is actually meant.

[1] <http://www.w3.org/TR/2008/WD-owl2-syntax-20081202/#Datatype_Maps>
[2] <http://www.w3.org/TR/2008/WD-owl2-semantics-20081202/#Data_Ranges>
[3] <http://www.w3.org/TR/2008/WD-owl2-syntax-20081202/#Individuals>

Dipl.-Inform. Michael Schneider
FZI Forschungszentrum Informatik Karlsruhe
Abtl. Information Process Engineering (IPE)
Tel  : +49-721-9654-726
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Email: Michael.Schneider@fzi.de
Web  : http://www.fzi.de/ipe/eng/mitarbeiter.php?id=555

FZI Forschungszentrum Informatik an der Universität Karlsruhe
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Received on Thursday, 8 January 2009 09:56:50 UTC

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