anchor.diff:          | Empty ->
               None
           | Lf (_, listSet) ->
  -            ListSet.TryFind (predicate, listSet)
  +            List.tryFind predicate listSet
           | Br (_,_,_,_) ->
               /// The stack of trie nodes pending traversal.
               let stack = Stack (defaultTraversalStackSize)
  
positive.code:                 else
                      Lf (j, result)
              else
                  PatriciaHashSet.Join (valueHash, Lf (valueHash, Tail value), j, set)
          | Br (p, m, t0, t1) ->
              if matchPrefix (valueHash, p, m) then
                  if zeroBit (valueHash, m) then
  
negative.code:             false
          | Lf (j, listSet) ->
              j = valueHash
              && List.contains value listSet
          | Br (_, m, t0, t1) ->
              PatriciaHashSet.Contains (
                  valueHash, value, (if zeroBit (valueHash, m) then t0 else t1))
  