(1)A company's profits from the sale of the whole or part of patent rights are—
(a)any capital sum comprised in the proceeds of sale, less
(b)the deductible costs.
(2)The deductible costs are—
(a)the capital cost (if any) of the rights sold, and
(b)any incidental expenses incurred by the company in connection with the sale.
(3)If—
(a)the company acquired the rights sold, or the rights out of which they were granted, by purchase,
(b)the company has previously sold part of the purchased rights, and
(c)the proceeds of that sale, after deducting any incidental expenses, consisted wholly or partly of a capital sum,
the capital cost is reduced by that sum.
(4)References in this Chapter to the capital cost of patent rights are to any capital sum included in any price paid by the company to purchase—
(a)the rights, or
(b)the rights out of which they were granted.
(5)This section needs to be read with sections 924 (relief for expenses: patent income) and 926 (contributions to expenditure).