2Subject to the provisions of this Schedule, from rent to which the person chargeable becomes entitled in a year of assessment there may be deducted the amount of any such payment as aforesaid which became due in the year of assessment or at an earlier time falling within the currency of the lease, in so far as the payment—
(a)was made in respect of the premises comprised in the lease, and
(b)in the case of a payment for maintenance or repairs, was incurred by reason of dilapidation attributable to a period falling within the currency of the lease or, in the case of any other payment, was incurred in respect of such a period:
Provided that where the person chargeable became the landlord after the lease began, references in the foregoing provisions of this paragraph to the currency of the lease shall not include any time before he became the landlord.