+ <!-- lccn number, a simpler index for id numbers -->
+ <index type="bf.lccn">
+ ?thing bf:lccn %v_lccn .
+ %v_lccn a bf:Identifier .
+ %v_lccn bf:identifierValue %v FILTER( %v = %s )
+ </index>
+
+ <!-- Find the instances of a given work -->
+ <index type="bf.work">
+ ?thing bf:instanceOf %u
+ </index>
+