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Re: possible semantic bugs concerning domain and range

From: pat hayes <phayes@ai.uwf.edu>
Date: Fri, 27 Sep 2002 22:48:11 -0500
Message-Id: <p05111b1bb9bad5fa9690@[65.217.30.172]>
To: "Jonathan Borden" <jonathan@openhealth.org>
Cc: www-webont-wg@w3.org

>Peter F. Patel-Schneider wrote:
>
>>
>>  It is not possible  to write [integer union string] in N-triples.
>>
>>  I should have been more explicit, and said that this was an XML-Schema
>>  derived class.
>
>Aha then this is a different issue. Well obviously the problem is due to the
>fact that OWL doesn't ... and most likely won't ... understand the nitty
>gritty details of XML Schema datatypes.
>
>The issue is that XML Schema union datatypes match lexical to value mappings
>in order that they were declared e.g.
>
>xsd:[integer union string] is intended to represent the datatype in which
>integer is declared first and hence the lexical value "10" maps to the
>integer 10, whereas in xsd:[string union integer] the lexical value "10"
>maps to the string "10". I find these sorts of aspects of XML Schema a bit
>quirky bordering on downright weird.

Right, and I think in fact that the WG has more or less decided to 
ignore them. We had feedback, as I recall, from people who helped 
develop the XML Schema specs who had not noticed these quirky 
properties of derived types and were worried about them. They may 
change, don't build there, was the message I took away from that 
discussion.

>
>>
>>  > I assume you mean:
>>  >
>>  > foo rdfs:range _:x .
>>  > _:x unionOf (xsd:integer, xsd:string) .
>>
>>  Well, sort of, but the union would be in XML-Schema, not in OWL.
>>
>... but one approach being touted for a
>>  while in the RDF Core was to have "the" range of the property determine
>>  which XML-Schema literal-to-value map to use.  However, this breaks down
>>  when super-properties can have different ranges (with non-compatible
>>  literal-to-value maps).
>>
>
>Yes, but I (and others) objected to RDF Core doing this for essentially the
>fact that one can't know what "the" range of a property is intended to be,

Guys, Im sorry I ever used this phrase, even with scare quotes. There 
isnt and can not be, such a thing as 'the' range. Lets all agree on 
that.

Pat
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Received on Friday, 27 September 2002 23:47:54 GMT

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