666Allowable loss treated as accruingU.K.
(1)If A exceeds B, an allowable loss equal to the amount of the excess is treated as accruing to the company in the accounting period for the purposes of corporation tax on chargeable gains.
(2)In this section—
A is the amount paid as mentioned in section 665(5) reduced (but not below nil) by an amount equal to the fair value of the host contract at the time that amount is paid,
B is the amount treated as the carrying value of the relevant contract mentioned in section 665(4) at the time the company became a party to the debtor relationship mentioned in section 665(2), and
“the host contract” means the loan relationship to which the company is treated as a party under section 415(2) (loan relationships with embedded derivatives) because of the debtor relationship.