static bool has_interface (Grob *);
static void add_element (Grob *me, Grob *add);
DECLARE_SCHEME_CALLBACK (calc_positioning_done, (SCM element));
static bool has_interface (Grob *);
static void add_element (Grob *me, Grob *add);
DECLARE_SCHEME_CALLBACK (calc_positioning_done, (SCM element));