10.9. Subject to section 9.1.1, the amount that an operator may deduct, under subparagraph b of subparagraph 2 of the second paragraph of section 8.1.1, in respect of class 1A property, class 2A property or class 3A property as a depreciation allowance in computing the mine-mouth output value in respect of a mine it operates, for a fiscal year, must not exceed the portion, reasonably attributable to the operation of the mine, of the least of
(1) the part of the capital cost of the property of that class, for the fiscal year;
(2) the undepreciated capital cost of the property of that class, before any deduction under that subparagraph b, at the end of the fiscal year; and
(3) where the operator no longer owns property of that class at the end of the fiscal year, zero.