fixed the overly restrictive types of filter and partition in Data.Set into polymorphic types

src/libraries/OS-Independent/Data/Set.dcl

@@ -370,8 +370,7 @@ intersections :: ![Set a] -> Set a | < a
  *     sort (toList (filter (pred p) xs))
  *         =.= sort (removeDup ('StdList'.filter (pred p) (toList xs)))
  */
-filter :: !(a -> Bool) !(Set a) -> Set a | < a
-	special a=Int; a=String
+filter :: !(a -> Bool) !(Set a) -> Set a
 
 /**
  * Partition the set into two sets, one with all elements that satisfy the
@@ -392,8 +391,7 @@ filter :: !(a -> Bool) !(Set a) -> Set a | < a
  *         (true`,false`) = (toList true, toList false)
  *         xs` = true` ++ false`
  */
-partition :: !(a -> Bool) !(Set a) -> (!Set a, !Set a) | < a
-	special a=Int; a=String
+partition :: !(a -> Bool) !(Set a) -> (!Set a, !Set a)
 
 /**
  * Split a set in elements less and elements greater than a certain pivot.

src/libraries/OS-Independent/Data/Set.icl

@@ -198,13 +198,13 @@ hedgeInt blo bhi (Bin _ x l r) t2
  * Filter and partition
  *--------------------------------------------------------------------*/
 
-filter :: !(a -> Bool) !(Set a) -> Set a | < a
+filter :: !(a -> Bool) !(Set a) -> Set a
 filter p (Bin _ x l r)
 	| p x       = link x (filter p l) (filter p r)
 	| otherwise = merge (filter p l) (filter p r)
 filter _ tip = tip
 
-partition :: !(a -> Bool) !(Set a) -> (!Set a, !Set a) | < a
+partition :: !(a -> Bool) !(Set a) -> (!Set a, !Set a)
 partition p (Bin _ x l r)
   #! (l1,l2) = partition p l
   #! (r1,r2) = partition p r