src/HOL/Typerep.thy

   then add_typerep tyco thy else thy;
 
 in
 
 add_typerep @{type_name fun}
-#> TypedefPackage.interpretation ensure_typerep
+#> Typedef.interpretation ensure_typerep
 #> Code.type_interpretation (ensure_typerep o fst)
 
 end
 *}