c->event_source ()->broadcast (ev);
arts = scm_reverse_x (listened, SCM_EOL);
for (; scm_is_pair (arts); arts = scm_cdr (arts))
c->event_source ()->broadcast (ev);
arts = scm_reverse_x (listened, SCM_EOL);
for (; scm_is_pair (arts); arts = scm_cdr (arts))