static Interval staff_extent (Grob *me, Grob *ref, Axis, Grob *staff, Axis);
static SCM calc_common (Grob *, Axis);
static Real minimum_distance (Grob *, Grob *, Axis);
static Interval staff_extent (Grob *me, Grob *ref, Axis, Grob *staff, Axis);
static SCM calc_common (Grob *, Axis);
static Real minimum_distance (Grob *, Grob *, Axis);