The object of this Division is to secure the payment of certain tax liabilities of the * head company of a * consolidated group where the head company fails to meet all of those liabilities by the time they become due and payable. Accordingly:
(a) if a relevant liability is not covered by a tax sharing agreement--this Division provides for a process to make certain entities that were * subsidiary members of the group for at least part of the period to which each tax liability relates jointly and severally liable with the head company for those liabilities; or
(b) if a relevant liability is covered by a tax sharing agreement--this Division:
(i) provides for a process to make each of those entities liable for the amount determined under the agreement in relation to the liability; but
(ii) exempts an entity from a liability determined under the agreement if it leaves the group in certain circumstances.