Schematron question

[disteve]

Can Schematron validate that an attribute value is unique within an XML
document? If so, what would the assert or report tests be? See below.

Ex.

<ALLOCATION type="CLASS" name="CLASS A"><!-- OK, "name" unique -->
<CLASS priority="1" name="Highest Priority">
<STORE name="Walmart A 1 1">1000</STORE>
<STORE name="Walmart A 1 2">1001</STORE> 2">
</CLASS>
<ALLOCATION type="CLASS" name="CLASS B"><!-- OK, "name" unique -->
<CLASS priority="1" name="Highest Priority">
<STORE name="Walmart A 1 1">1000</STORE>
<STORE name="Walmart A 1 2">1001</STORE> 2">
</CLASS>
<ALLOCATION type="CLASS" name="CLASS B"><!-- FAILED, not unique -->
<CLASS priority="1" name="Highest Priority">
<STORE name="Walmart A 1 1">1000</STORE>
<STORE name="Walmart A 1 2">1001</STORE> 2">
</CLASS>