(1) In this section, "basis period", in relation to any year of assessment, means the period on the profits or gains of which income tax for that year is finally computed under Case I of Schedule D in respect of the trade or, where by virtue of the Income Tax Acts the profits or gains of any other period are taken to be the profits or gains of that period, that other period.
(2) Where -
(a) a person (in this section referred to as "the vendor") carrying on a trade of dealing in or developing land (in this section referred to as "the trade") disposes in the course of the trade of the full interest acquired by the person in any land,
(b) the person to whom the disposition is made (in this section referred to as "the purchaser") is not connected with the vendor,
(c) the terms subject to which the disposition is made provide for the grant of a lease of the land by the purchaser to the vendor,
(d) a sum representing the value of the vendor's right to be granted a lease is to be taken into a
…