int sn_stage_comparator_add (sn_stage_t *s, const sn_comparator_t *c);
int sn_stage_comparator_remove (sn_stage_t *s, int c_num);
int sn_stage_comparator_check_conflict (sn_stage_t *s, const sn_comparator_t *c);
int sn_stage_show (sn_stage_t *s);
int sn_stage_invert (sn_stage_t *s);
int sn_stage_comparator_add (sn_stage_t *s, const sn_comparator_t *c);
int sn_stage_comparator_remove (sn_stage_t *s, int c_num);
int sn_stage_comparator_check_conflict (sn_stage_t *s, const sn_comparator_t *c);
int sn_stage_show (sn_stage_t *s);
int sn_stage_invert (sn_stage_t *s);