(1) A is the aggregate of(a) subject to sections 16.14 to 16.18, the aggregate of all amounts each of which is expenses incurred by the operator, in respect of the mine, after 30 March 2010 and before that time, in sinking or excavating a mine shaft, main haulage way or similar underground work designed for continuing use, built or excavated after the mine came into production in reasonable commercial quantities, or in extending any such shaft, haulage way or work, and;
(b) the aggregate of all amounts each of which is an amount repaid by the operator before that time pursuant to a legal obligation to repay, in whole or in part, government assistance relating to an amount referred to in subparagraph a; and
(2) B is the aggregate of(a) the aggregate of all amounts each of which is an amount deducted by the operator for a fiscal year that ends after 30 March 2010 and before that time, as a post-production development allowance in respect of expenses incurred after 30 March 2010, under subparagraph e.3 of paragraph 2 of section 8, as it read on 30 March 2010, or under subparagraph c of subparagraph 2 of the fourth paragraph of section 8, and
(b) the aggregate of all amounts each of which is an amount of government assistance relating to an amount referred to in subparagraph a of subparagraph 1 that the operator received or was entitled to receive before that time.