}
</index>
+ <!-- isbn index. The Instance may contain a isbn10 or isbn13. -->
+ <!-- These can be literal values like -->
+ <!-- http://isbn.example.org/1906833214 which we need to search -->
+ <!-- by our usual substring match. Or they can be links to Identivfiers -->
+ <!-- which will have a proper identifierValue on which we can do -->
+ <!-- an exact match -->
+ <index type="bf.isbn">
+ {
+ ?thing bf:isbn10 %v
+ FILTER(contains(str(%v), %s))
+ } UNION {
+ ?thing bf:isbn13 %v
+ FILTER(contains(str(%v), %s))
+ } UNION {
+ {
+ ?thing bf:isbn10 ?isbn
+ } UNION {
+ ?thing bf:isbn13 ?isbn
+ }
+ ?isbn a bf:Identifier .
+ ?isbn bf:identifierValue %v FILTER( %v = %s )
+ }
+ </index>
+
+
<!-- Present formats. BF-L comes from "thing" -->
<!-- Full instance, with the related work too -->
<present type="BF-V">