static int shift_compare (Grob *const &, Grob *const &);
static Direction dir (Grob *me);
static Grob *accidentals (Grob *me);
+ static Grob *arpeggio (Grob *me);
static Slice head_positions_interval (Grob *me);
static Direction static_dir (Grob *);
static void translate_rests (Grob *me, int dy);