Where under this Act--
(a) any person is deemed to be the secondary taxpayer in respect of any land or interest, and
(b) it is provided that there shall be deducted from the land tax payable by the secondary taxpayer, in respect of the land or interest, such amount (if any) as is necessary to prevent double taxation,the amount of the deduction (if any) shall be the lesser of the following amounts--
(i) the amount of land tax payable in respect of the land or interest by the secondary taxpayer, or
(ii) the amount of land tax (if any) payable in respect of the land or interest by the primary taxpayer aggregated with the amount of land tax (if any) payable in respect of the land or interest by a precedent secondary taxpayer (if any)--Provided that the secondary taxpayer shall be assessed and liable in respect of the land or interest, notwithstanding that the primary taxpayer is exempt from taxation in respect of the land or interest, or that there is no primary taxpayer in respect of the land or interest.