anchor.diff:      /// Returns the number of intervals in the set.
       let intervalCount (tree : CharDiet) =
           // Preconditions
  -        assert (dietInvariant tree)
  -        assert (fst <| intervalsDisjoint tree Set.empty)
  +        //assert (dietInvariant tree)
  +        //assert (fst <| intervalsDisjoint tree Set.empty)
   
           // OPTIMIZE : Modify this to use a mutable stack instead of an F# list.
           let rec cardinal_aux acc = function
  
positive.code:     /// Gets the maximum (greatest) value stored in the DIET.
      let maxElement (tree : CharDiet) : char =
          // Preconditions
          assert (dietInvariant tree)
          assert (fst <| intervalsDisjoint tree Set.empty)
  
          match tree with
          | Empty ->
  
negative.code:         | Node (left, right, (x, y), _) ->
              if p < safePred x then
                  let p', left' = find_del_right p left
                  p', CharDiet.Join (comparer, left', right, (x, y))
              elif p > y then
                  find_del_right p right
              else
  