virtual void handle_prebroken_dependencies ();
virtual Interval_t<int> spanned_rank_interval () const;
virtual Interval pure_height (Grob *ref, int start, int end);
virtual void handle_prebroken_dependencies ();
virtual Interval_t<int> spanned_rank_interval () const;
virtual Interval pure_height (Grob *ref, int start, int end);