Evaluates an expression and returns its meaning as a node set.
If expression can be construed as an XPath node set, this is what is returned.
If expression begins with a < character, an attempt is made to interpret it as a node set.
In remaining cases, as in the example below, expression is interpreted as a path leading to an XML document and if an XML file is found at the endpoint of the path, its content is returned as a node set.
This example returns the content of an XML document in a file named "c:\temp\root.xml" as a node set.
Contrast with the following, which returns a text node with string-value "c:temp\root.xml":