(a)"cost of the project" means the actual cost of the fixed assets, being land, buildings, leaseholds, plant, machinery, furniture, fittings and railway sidings (including expenditure on development of land and buildings) and—(i)for cases under sub-section (1)(a), the actual cost as shown in the books of the assessee as on the last day of the tax year in which the business commences;(ii)for cases under sub-section (1)(b), the actual cost as shown in the books of the assessee as on the last day of the tax year in which either the extension of the undertaking is completed, or the new unit commences production or operations, as the case may be, in so far as such fixed assets have been acquired or developed in connection with the extension of the undertaking or setting up of new unit;