[xsl] logic for writing two nested for-loops given a condition

[RahilQ <qamar_rahil@xxxxxxxxxxx>]

Hi

Ive been trying to work out the logic for solving my problem all of 
yesterday and have given up!

I have two for loops. The first for loop runs through the first file 
First.xml such that

<xsl:for-each 
select="document(First.xml)/SubConcepts/SubConcept">.............</xsl:for-each> 
<!--extract the '@name' value-->

The second for loop is nested within the first loop and is as such

<xsl:for-each 
select="document(Second.xml)/SubConcepts/SubConcept[1]/Value">  
<!--check if contains( '@name=text()' ) -->

What I want to do is look for the '@name' value in the rest of the 
'document(Second.xml)/SubConcepts/SubConcept' ONLY IF I dont find a 
match in the earlier SubConcept node's Value nodes.

How do I go about coding this?

Thanks
Rahil