xs:whiteSpace weirdness

I find Part 2 sometimes confusing about the whiteSpace facet...

The schema for schema says:

<xs:simpleType name="double" id="double">
  <xs:annotation>
   <xs:appinfo>
    <hfp:hasFacet name="pattern"/>
    <hfp:hasFacet name="enumeration"/>
    <hfp:hasFacet name="whiteSpace"/>
    <hfp:hasFacet name="maxInclusive"/>
    <hfp:hasFacet name="maxExclusive"/>
    <hfp:hasFacet name="minInclusive"/>
    <hfp:hasFacet name="minExclusive"/>
    <hfp:hasProperty name="ordered" value="total"/>
    <hfp:hasProperty name="bounded" value="true"/>
    <hfp:hasProperty name="cardinality" value="finite"/>
    <hfp:hasProperty name="numeric" value="true"/>
   </xs:appinfo>
  <xs:documentation
         source="http://www.w3.org/TR/xmlschema-2/#double"/>
  </xs:annotation>

  <xs:restriction base="xs:anySimpleType">
   <xs:whiteSpace value="collapse"  fixed="true"
         id="double.whiteSpace"/>
  </xs:restriction>
</xs:simpleType>

And the text of the rec says:

"whiteSpace is applicable to all ·atomic· and ·list· datatypes. For all 
·atomic· datatypes other than string (and types ·derived· by 
·restriction· from it) the value of whiteSpace is collapse and cannot be 
changed by a schema author;"

And also:

"double has the following ·constraining facets·:

     * pattern
     * enumeration
     * whiteSpace
     * maxInclusive
     * maxExclusive
     * minInclusive
     * minExclusive"

My question is: why do we consider whiteSpace to be a facet of double 
(and many other datatypes) if the schema author cannot change it (which 
is confirmed by the fixed attribute in whiteSpace facet of the double 
type definition)?

Is-it only to let schema author to repeat that whiteSpace is collapse in 
their derivations? If yes, isn't it more confusing since they may think 
that this facet hasn't been fixed? BTW, why has it been fixed in the 
schema for schema since when whiteSpace is collapse this value cannot be 
changed in further restrictions anyway ?

Thanks

Eric
-- 
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                                           http://dyomedea.com/formation/
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Eric van der Vlist       http://xmlfr.org            http://dyomedea.com
http://xsltunit.org      http://4xt.org           http://examplotron.org
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Received on Monday, 8 October 2001 03:30:55 UTC