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<!DOCTYPE bugzilla SYSTEM "https://www.w3.org/Bugs/Public/page.cgi?id=bugzilla.dtd">

<bugzilla version="5.0.4"
          urlbase="https://www.w3.org/Bugs/Public/"
          
          maintainer="sysbot+bugzilla@w3.org"
>

    <bug>
          <bug_id>3724</bug_id>
          
          <creation_ts>2006-09-13 20:09:47 +0000</creation_ts>
          <short_desc>Rule &quot;Content type restricts&quot; needs clarification</short_desc>
          <delta_ts>2008-02-08 23:24:46 +0000</delta_ts>
          <reporter_accessible>1</reporter_accessible>
          <cclist_accessible>1</cclist_accessible>
          <classification_id>1</classification_id>
          <classification>Unclassified</classification>
          <product>XML Schema</product>
          <component>Structures: XSD Part 1</component>
          <version>1.1 only</version>
          <rep_platform>Macintosh</rep_platform>
          <op_sys>All</op_sys>
          <bug_status>RESOLVED</bug_status>
          <resolution>FIXED</resolution>
          
          
          <bug_file_loc></bug_file_loc>
          <status_whiteboard>restriction cluster</status_whiteboard>
          <keywords>resolved</keywords>
          <priority>P2</priority>
          <bug_severity>normal</bug_severity>
          <target_milestone>---</target_milestone>
          
          
          <everconfirmed>1</everconfirmed>
          <reporter name="C. M. Sperberg-McQueen">cmsmcq</reporter>
          <assigned_to name="C. M. Sperberg-McQueen">cmsmcq</assigned_to>
          
          
          <qa_contact name="XML Schema comments list">www-xml-schema-comments</qa_contact>

      

      

      

          <comment_sort_order>oldest_to_newest</comment_sort_order>  
          <long_desc isprivate="0" >
    <commentid>11668</commentid>
    <comment_count>0</comment_count>
    <who name="C. M. Sperberg-McQueen">cmsmcq</who>
    <bug_when>2006-09-13 20:09:47 +0000</bug_when>
    <thetext>The constraint &quot;Content type restricts&quot; reads in part:

    1 If BCT&apos;s {variety} is empty, then either there is no 
      sequence of element information items which is ·locally 
      valid· with respect to RCT&apos;s {particle}, or only the 
      empty sequence is.

This seems to assume that RCT has a particle, which is not
true if RCT has {variety} of &apos;empty&apos; or &apos;simple&apos;.

The only part of the spec that depends on this constraint
is Schema Component Constraint: Derivation Valid (Restriction, 
Complex), and the thicket of conditionals there is too thick 
for me to tell whether any actual harm results from leaving
&quot;Content type restricts&quot; undefined for various cases.  

I think the &apos;Content type restricts&apos; rule would be more
useful if it provided a predicate which is true or false for
any pair of content types, instead of providing one which
is true for some, false for some, and undefined for some.
Making this definition more general might also make possible
a simplification of &quot;Derivation Valid (Restriction, Complex)&quot;.</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>18750</commentid>
    <comment_count>1</comment_count>
    <who name="C. M. Sperberg-McQueen">cmsmcq</who>
    <bug_when>2008-02-05 02:31:52 +0000</bug_when>
    <thetext>A wording proposal for this issue (among others) was sent to the XML
Schema WG on 4 February 2008.

http://www.w3.org/XML/Group/2004/06/xmlschema-1/structures.consent.200802.html (member-only link)

For some issues, the proposal is effectively to make no change;
see the Status section of the proposal for the specifics.</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>18934</commentid>
    <comment_count>2</comment_count>
    <who name="C. M. Sperberg-McQueen">cmsmcq</who>
    <bug_when>2008-02-08 23:24:46 +0000</bug_when>
    <thetext>During its telcon today, the XML Schema WG accepted the &apos;Structures
Omnibus 2&apos; proposal, which includes changes intended to resolve this
issue.  (Or, for some issues, contains the editors&apos; proposal that the
issue should be closed without further changes.)
http://www.w3.org/XML/Group/2004/06/xmlschema-1/structures.consent.200801.html (member-only link)

Accordingly, I&apos;m marking the issue resolved.

The originator of this issue (or in some cases the individual,
acting on behalf of a group, who filed the comment) should receive 
an email notification of this change.

Please examine the changes and let us know if you agree with this
resolution of your issue, by adding a comment to the issue record and
changing the Status of the issue to Closed. Or, if you do not agree
with this resolution, please add a comment explaining why. If you wish
to appeal the WG&apos;s decision to the Director, then also change the
Status of the record to Reopened. If you wish to record your dissent,
but do not wish to appeal the decision to the Director, then change
the Status of the record to Closed. If we do not hear from you in the
next two weeks, we will assume you agree with the WG decision.

</thetext>
  </long_desc>
      
      

    </bug>

</bugzilla>