/** A symbol which is attached between two columns. A spanner is a
symbol which spans across several columns, so its final appearance
/** A symbol which is attached between two columns. A spanner is a
symbol which spans across several columns, so its final appearance
virtual void do_unlink();
virtual void do_junk_links();
virtual void do_brew_molecule ();
virtual void do_unlink();
virtual void do_junk_links();
virtual void do_brew_molecule ();
virtual void do_break_processing();
virtual Interval do_width() const;
virtual void do_print() const;
virtual void do_break_processing();
virtual Interval do_width() const;
virtual void do_print() const;