10.16. For the purposes of subparagraph f of subparagraph 2 of the fourth paragraph of section 8 and subparagraph e of subparagraph 2 of the second paragraph of section 8.1.1, if, at the end of a fiscal year, an operator no longer owns class 3A property or class 4A property, the amount that the operator is required to deduct in computing its annual earnings from a mine for the fiscal year, and in computing the mine-mouth output value in respect of the mine, for the fiscal year, in respect of property of that class, is equal to the amount by which the aggregate of the amounts referred to in subparagraphs a to d of paragraph 1 of the definition of “undepreciated capital cost” in the first paragraph of section 9, in respect of property of that class, exceeds the aggregate of the amounts referred to in subparagraphs a to h of paragraph 2 of the definition of that expression, up to the portion of the excess amount that is reasonably attributable to the operation of the mine.