for (i = 0; i < 2; i++)
  {
    if (node->pbst_link[i] != NULL
        && node->pbst_link[i]->pbst_parent != node)
      {
        printf (" Node %d has parent %d (should be %d).\n",
                *(int *) node->pbst_link[i]->pbst_data,
                (node->pbst_link[i]->pbst_parent != NULL
                 ? *(int *) node->pbst_link[i]->pbst_parent->pbst_data : -1),
                d);
        *okay = 0;
      }
  }
