(3)The deduction referred to in sub-section (1) shall be––(a)for the period before the beginning of commercial production, expenditure towards infructuous or abortive exploration incurred in respect of any surrendered area;(b)for the period after the commencement of commercial production, expenditure (whether before or after such production) in respect of drilling or exploration activities or services or in respect of physical assets used in that connection;(c)for the tax year of commencement of commercial production and such succeeding tax years as specified in the agreement, towards depletion of mineral oil in the mining area.
