Y_AXIS);
chain_callback (e, outside_slur_cross_staff_proc, ly_symbol2scm ("cross-staff"));
e->set_object ("slur", slur->self_scm ());
Y_AXIS);
chain_callback (e, outside_slur_cross_staff_proc, ly_symbol2scm ("cross-staff"));
e->set_object ("slur", slur->self_scm ());