[Bug 2781] restriction relation among facet values needed

http://www.w3.org/Bugs/Public/show_bug.cgi?id=2781

           Summary: restriction relation among facet values needed
           Product: XML Schema
           Version: 1.1 only
          Platform: PC
        OS/Version: Linux
            Status: NEW
          Severity: normal
          Priority: P2
         Component: Structures: XSD Part 1
        AssignedTo: ht@w3.org
        ReportedBy: cmsmcq@w3.org
         QAContact: www-xml-schema-comments@w3.org


Clause 1.3.2 of Schema Component Constraint: Derivation Valid
(Restriction, Simple) in section 3.14.6 of Structures reads:

    1.3.2 If there is a facet of the same kind in the {facets} of the
    {base type definition} (call this BF), then the DF's {value} is a
    valid restriction of BF's {value} as defined in [XML Schema:
    Datatypes].

The concept of one facet value being 'at least as strong as' another
value for the same facet is a very useful one, and it is good that
Structures appeals to it here.  The problem is that this is a throw
which the Datatypes spec does not catch very well: the notion is
reasonably well covered with various component constraints about
restrictions that are valid or invalid, but the Datatypes spec does
not provide any single definition for the terminology used in the call
from Structures, or for any other term for the concept.

This is an editorial change that should be made before we finish.

Received on Monday, 30 January 2006 18:36:12 UTC