Purpose of requirement in 3.16.6.2 Derivation Valid (Restriction, Simple) in XSD 1.1?

• From: Kevin Braun <kbraun@obj-sys.com>
• Date: Fri, 02 Oct 2009 11:57:54 -0400
• To: xmlschema-dev@w3.org
• Message-ID: <4AC62302.8000903@obj-sys.com>

Hi,

In 3.16.6.2 Derivation Valid (Restriction, Simple)
(http://www.w3.org/TR/xmlschema11-1/#cos-st-restricts), step 3.1.2.3
says: "Each type definition in D.{member type definitions}
<http://www.w3.org/TR/xmlschema11-1/#std-member_type_definitions> is
validly ·derived· <http://www.w3.org/TR/xmlschema11-1/#key-derived> from
the corresponding type definition in B.{member type definitions}
<http://www.w3.org/TR/xmlschema11-1/#std-member_type_definitions>, as
defined in Type Derivation OK (Simple) (§3.16.6.3)
<http://www.w3.org/TR/xmlschema11-1/#cos-st-derived-ok>."

What purpose does this requirement serve?  Isn't it the case that
D.{member type definitions} is identical to B.{member type definitions},
since this case applies when defining a restriction on a union?  Am I
missing something, or is this superfluous?

Thanks,
Kevin

Received on Friday, 2 October 2009 15:59:52 UTC