Why guarantee parent-child relationship to be invertible ?

• From: TAN Kuan Hui <kuanhui@mobileworkspace.com>
• Date: Fri, 1 Mar 2002 16:33:13 +0800
• To: <www-xml-query-comments@w3.org>
• Message-ID: <000601c1c0fb$bbb04420$200000c0@pinecone>

Section 4.2 Elements in data model,

The following para,

"To guarantee that the parent-child relationship is invertible, the element
constructors logically create a copy of all of their namespace, attribute,
and children arguments and set the parent property of these nodes to the
newly created element node."

Why is there a need to guarantee that the parent-child relationship
to be invertible ? This seems to suggest that their type relationship 
somehow can also be inverted, which does not make sense to me. 
Could anyone explain what the clause above means exactly ? Is 
there any impact if the invertibility cannot be complied with ?

Thanks.
Kuan Hui

Received on Friday, 1 March 2002 03:34:14 UTC