úÎ 2M      cursor z! returns the targeted element in z. 6This function is not total, but the invariant is that  endp z == False means that you can safely call  cursor z.  replace a z+ changes the current element in the zipper : to the passed in value. If there is no current element, : the zipper is unchanged. If you want to add the element  in that case instead, use insert a (delete z).         ListZipper-1.0.0.0Data.List.ZipperZipperZipemptyfromList fromListEndtoListbeginpendpemptypcursorleftrightinsertpushdeletepopreplace