Best way to compare two XML files for equivalence (subset)

[Tim Smith]

Hi,

I have two XML files and I want to check each value in one file to see
if it exists in the other file - following the same path. The XML
files have equivalent schema definitions. Is there an easy way
programmatically or using XSLT?

Sample file to match with
<MyXML>
<Branch>
<Item>
<Nbr>12</Nbr>
</Item>
</Branch>
<Empty/>
<SomewhatEmpty>
<Nothing/>
</SomewhatEmpty>
</MyXML>

Sample file to match on
<MyXML>
<Branch>
<Item>
<Nbr>12</Nbr>
</Item>
</Branch>
<Branch>
<Item>
<Nbr>56</Nbr>
</Item>
</Branch>
<Empty/>
<SomewhatEmpty>
<Nothing/>
</SomewhatEmpty>
</MyXML>

So it would return true in this case since the only value 12 - did
exist in the file to match on.