“…Notable methods of this kind include the alternating projection algorithm [5,29,17], the Douglas-Rachford (DR) algorithm [37,43,38], and many extensions and variants [19,20,10,48]. Even in settings without convexity [1,2,3,16,41,42], such methods remain a popular choice due largely to their simplicity, ease-of-implementation and relatively -often surprisingly -good performance.…”