add_mml(MinMax* to, MinMax* from)
{
  to->min = distance_add(to->min, from->min);
  to->max = distance_add(to->max, from->max);
}
add_mml(MinMax* to, MinMax* from)
{
  to->min = distance_add(to->min, from->min);
  to->max = distance_add(to->max, from->max);
}