int __cs_cond_wait(__cs_cond_t *cond, __cs_mutex_t *mutex) { __cs_mutex_unlock(mutex); assume(*cond != -1); __cs_mutex_lock(mutex); return 0; }
 int __cs_cond_wait_1(__cs_cond_t *__cs_cond_to_wait_for, __cs_mutex_t *__cs_m)
 {
 __CPROVER_assert((*__cs_cond_to_wait_for) != 0, "attempt to use an uninitialized conditional variable");
 __CPROVER_assert((*__cs_cond_to_wait_for) != (-2), "attempt to use a destroyed conditional variable");
 __cs_mutex_unlock(__cs_m);
 }