Such would be the case if the postal service requires two sortations to get the mail to the 5-digit level while the computer goes there directly.
If the postal service requires two sortations to get the mail to the 5-digit level, this would be the case.
mnli hypothesis: If the postal service requires two sortations to get the mail to the 5-digit level, this would be the case. premise: Such would be the case if the postal service requires two sortations to get the mail to the 5-digit level while the computer goes there directly.