RE: Data Model - 4.2.1

> In Data Model 4.2.1 it is stated that the XQuery 1.0 document node is 
> "essentially identical" to an XPath 1.0 root node. I am 
> dubious about that 
> statement.
> 
> My understanding of an XPath 1.0 root node is that it was 
> limited to having 
> only one element node child, which is not the case for the XQuery 1.0 
> document node. So they are not identical.

On the contrary, this capability was included in the XPath 2.0 data model
specifically for backwards compatibility with XPath 1.0. It is needed to
support an XSLT construct such as:

<xsl:variable name="x">
  <e/>
  <e/>
</xsl:variable>

It also turns out to be useful, I understand, in mapping the data model to
relational databases.

Michael Kay
Software AG