anchor.diff:          List.rev resultList2,
           List.rev resultList3
   
  +/// <summary>
   /// Returns a list containing the elements generated by the given computation.
   /// The given initial state argument is passed to the element generator, which is applied
  -/// repeatedly until a None value is returned. Each call to the element generator returns
  -/// a new residual state.
  +/// repeatedly until a <c>None</c> value is returned.
  +/// Each call to the element generator returns a new residual state.
  +/// </summary>
  +/// <param name="generator"></param>
  +/// <param name="state"></param>
  +/// <returns></returns>
   [<CompiledName("Unfold")>]
   let unfold (generator : 'State -> ('T * 'State) option) (state : 'State) : 'T list =
       // Preconditions
  
positive.code:         List.rev resultList1,
          List.rev resultList2
  
  /// Returns the number of list elements matching a given predicate.
  // List.countWith predicate list = (List.filter predicate list |> List.length)
  [<CompiledName("CountWith")>]
  let countWith (predicate : 'T -> bool) (list : 'T list) : int64 =
      // Preconditions
  
negative.code:     // Return the result list.
      resultList
  
  /// <summary>
  /// Applies the given function to each element of the list and creates two (2) lists
  /// from the components of the returned tuple.
  /// </summary>
  /// <param name="mapping"></param>
  /// <param name="list"></param>
  /// <returns></returns>
  [<CompiledName("UnzipWith")>]
  let unzipWith (mapping : 'T -> 'U * 'V) list : 'U list * 'V list =
      // Preconditions
  