static int normal_stem_count (Grob *);
static Grob *first_normal_stem (Grob *);
static Grob *last_normal_stem (Grob *);
- DECLARE_GROB_INTERFACE ();
static void add_stem (Grob *, Grob *);
static bool is_cross_staff (Grob *);
static bool is_knee (Grob *);