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RE: Derivation by restriction

From: Xan Gregg <Xan.Gregg@jmp.com>
Date: Thu, 8 Apr 2004 16:30:08 -0400
Message-ID: <939FBCFFFF9B0C40BF8B53294E2296DB4AFA93@merc20.na.sas.com>
To: "Jack Lindsey" <tuquenukem@hotmail.com>, <xmlschema-dev@w3.org>

Your premise is incorrect.  You can have a restriction that makes an optional element mandatory.  Or is there some other constraint involved that is not apparent in your message?

xan

-----Original Message-----
From:  Jack Lindsey
Sent: Thursday, April 08, 2004 4:24 PM
To: xmlschema-dev@w3.org
Subject: Derivation by restriction

Would I be correct in concluding that when deriving a complex type by 
restriction, while it is possible to make an optional attribute mandatory in 
the subtype, it is not possible to make the presence of an element 
mandatory?

If so, why not?  If this does not offend the concept of inheritance 
overriding in the case of an attribute why has this facility not been 
implemented for elements?
Received on Thursday, 8 April 2004 16:30:31 UTC

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