void actlist_delete(actlist_t*a, segment_t*s);
void actlist_swap(actlist_t*a, segment_t*s1, segment_t*s2);
segment_t* actlist_left(actlist_t*a, segment_t*s);
segment_t* actlist_leftmost(actlist_t*a);
void actlist_delete(actlist_t*a, segment_t*s);
void actlist_swap(actlist_t*a, segment_t*s1, segment_t*s2);
segment_t* actlist_left(actlist_t*a, segment_t*s);
segment_t* actlist_leftmost(actlist_t*a);