+ system_specs = scm_reverse_x (system_specs, SCM_EOL);
+ return system_specs;
+}
+
+SCM
+Paper_book::systems ()
+{
+ if (systems_ != SCM_BOOL_F)
+ return systems_;
+
+ systems_ = SCM_EOL;
+ SCM specs = get_system_specs ();
+ for (SCM s = specs; scm_is_pair (s); s = scm_cdr (s))
+ {
+ if (Paper_score *pscore = dynamic_cast<Paper_score*> (unsmob_music_output (scm_car (s))))
+ {
+ SCM system_list = scm_vector_to_list (pscore->get_paper_systems ());
+ system_list = scm_reverse (system_list);
+ systems_ = scm_append (scm_list_2 (system_list, systems_));
+ }
+ else
+ {
+ systems_ = scm_cons (scm_car (s), systems_);
+ }
+ }
+