+class Horizontal_group_item : public Axis_group_item, public Horizontal_group_element {
+protected:
+ virtual void remove_all() { Horizontal_group_element::remove_all(); }
+ virtual void do_print() const;
+public:
+ virtual void add_element(Score_elem*e) { Horizontal_group_element::add_element(e); }
+ virtual void remove_element(Score_elem*e) { Horizontal_group_element::remove_element(e); }