// todo: move to somewhere else.
Real get_broken_left_end_align () const;
void substitute_one_mutable_property (SCM sym, SCM val);
// todo: move to somewhere else.
Real get_broken_left_end_align () const;
void substitute_one_mutable_property (SCM sym, SCM val);
void set_bound (Direction d, Grob *);
Item *get_bound (Direction d) const;
void set_bound (Direction d, Grob *);
Item *get_bound (Direction d) const;
static bool less (Spanner *const &, Spanner *const &);
virtual Grob *find_broken_piece (System *) const;
virtual void derived_mark () const;
static bool less (Spanner *const &, Spanner *const &);
virtual Grob *find_broken_piece (System *) const;
virtual void derived_mark () const;