Determine Whether the Following Is Valid or Invalid

Short Answer

Determine whether the following is valid or invalid:
Either the bank made a mistake, or none of this month's deposits have been recorded. If our accountant is correct, then all the accounts have been reconciled. If it is not the case that none of the month's deposits has been recorded, then all the accounts could not have been reconciled. I have checked with our accountant, and he is indeed correct. Therefore, the only alternative is that the bank made a mistake.