--- a/src/Pure/Tools/class_package.ML Fri May 05 21:59:43 2006 +0200
+++ b/src/Pure/Tools/class_package.ML Fri May 05 21:59:43 2006 +0200
@@ -162,7 +162,7 @@
fun get_superclass_derivation thy (subclass, superclass) =
if subclass = superclass
then SOME [subclass]
- else case Graph.find_paths ((fst o fst o ClassData.get) thy) (subclass, superclass)
+ else case Graph.irreducible_paths ((fst o fst o ClassData.get) thy) (subclass, superclass)
of [] => NONE
| (p::_) => (SOME o filter (is_operational_class thy)) p;