Simultaneous_music_iterator::derived_substitute (Context *f, Context *t)
{
for (SCM s = children_list_; scm_is_pair (s); s = scm_cdr (s))
Simultaneous_music_iterator::derived_substitute (Context *f, Context *t)
{
for (SCM s = children_list_; scm_is_pair (s); s = scm_cdr (s))