import Prelude hiding (filter,foldr,foldl,null,map)
import Data.Monoid
import qualified Data.List as List
+import Data.Typeable
{-
-- just for testing
{--------------------------------------------------------------------
+ Typeable/Data
+--------------------------------------------------------------------}
+
+#include "Typeable.h"
+INSTANCE_TYPEABLE1(Set,setTc,"Set")
+
+{--------------------------------------------------------------------
Utility functions that return sub-ranges of the original
tree. Some functions take a comparison function as argument to
allow comparisons against infinite values. A function [cmplo x]