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RE: <restriction> - Bad Kleene Notation

From: MacAndrew, Tim <tmacandrew@NetSilicon.com>
Date: Fri, 28 Sep 2001 09:35:42 -0700
Message-ID: <AD77174F26BFD411BE7B00508BFDF56211FCA8@newbury.netsilicon.com>
To: <zongaro@ca.ibm.com>, <www-xml-schema-comments@w3.org>
Hello Henry,

	Thank you for responding to my e-mail about the
<restriction> statement in XML Schema.  Thank you for
referencing the sections of the Schema documents that
clarify the usage of the <restriction> statement.

	However, it does appear that the use of the Kleene
Operator in the XML Schema document is incorrect.  I don't
believe it is valid to define "conditions" that change the
definition of the "*" operator.  Since the "*" operator
is _defined_ to mean "zero or more occurrences of", it
is erroneous to then (verbally) qualify the operator in other
sections of the document.  This is similar to changing
the meaning of the mathematical "+" operator.  I believe the
production rule for the definition of the <restriction>
statement is invalid and the editors should correct it.
(Reference: XML Schema Part 1: Structures - 3.4.2 XML
Representation of Complex Type Definitions
http://www.w3.org/TR/2001/REC-xmlschema-1-20010502/#element-simpleConten
t::restriction)

	I must say that I'm impressed with the "XML Schema
Quality Checker" developed at IBM.  That tool has eliminated
much of the confusion intrinsic to the Schema documents from
the W3C.  Thank you.

Tim MacAndrew
e-mail: TMacAndrew@NetSilicon.com
Received on Friday, 28 September 2001 12:35:45 GMT

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