Sale and Leaseback - Proceeds above market value

In e.g 4 part 2 when the proceeds are 11 million. Sir you have calculated right to use asset and gains on the basis of discounted lease liability 7721735 while in BPP textbook (e.g 3.3 sale and leaseback pg 216) it is shown that the excess amount of fair value (1million in our e.g) will be deducted from the total discounted lease liability (7721735 in our e.g) and right to use asset and gains transferred will be calculated on the basis of this amount. Accordingly , in our e.g , it will be - 7721735 - 1000000 = 6721735 Right to use asset = 6721735/10000000* 8400000 = 5646257 Gains = 1600000 * 0.6721735 = 1075477 1600000 - 1075477 = 524523 Therefore journal entry will be DR. Cash 11000000 DR. Right to use asset 5646257 CR. Asset 8400000 CR. Lease liability 7721735 CR. Gains 524523 Above entries are balancing. The difference between our approach and BPP is that BPP is deducting excess amount above market value from the total discounted lease liability and calculating right to use asset and gains on the basis of that amount, while showing the lease liability at discounted amount in financial statements. We are recording lease liability at discounted value + excess above market value. And calculating right to use asset and gains on the basis of full discounted value i.e 7721735. Please clarify which treatment is correct to follow in exams ? Thanks for your time.