anchor.diff:      for i = 0 to len - 1 do
           action.Invoke (resizeArray1.[i], resizeArray2.[i])
   
  -//
  +/// <summary>
  +/// Apply the given function to pair of elements drawn from matching indices in two arrays,
  +/// also passing the index of the elements. The two arrays must have the same lengths, 
  +/// otherwise an <c>ArgumentException</c> is raised.
  +/// </summary>
   [<CompiledName("IterIndexed2")>]
   let iteri2 action (resizeArray1 : ResizeArray<'T1>) (resizeArray2 : ResizeArray<'T2>) : unit =
       // Preconditions
  
positive.code:         results.Add (resizeArray1.[i], resizeArray2.[i])
      results
  
  //
  [<CompiledName("Unzip")>]
  let unzip (resizeArray : ResizeArray<'T1 * 'T2>) : ResizeArray<'T1> * ResizeArray<'T2> =
      // Preconditions
  
negative.code:     
      resizeArray.GetRange (start, count)
  
  /// Fill a range of the collection with the given element.
  [<CompiledName("Fill")>]
  let fill (resizeArray : ResizeArray<'T>) start count value : unit =
      // Preconditions
  