10.12. The amount that an operator is required to include in computing its annual earnings from a mine for a fiscal year, under subparagraph e of subparagraph 1 of the fourth paragraph of section 8, and in computing the mine-mouth output value in respect of the mine it operates, for the fiscal year, under subparagraph e of subparagraph 1 of the second paragraph of section 8.1.1, in respect of class 1A property or class 2A property, is equal to the proportion of the amount determined under the second paragraph that the use of the property of the class that is reasonably attributable to the operation of the mine for the particular fiscal year is of the total use of that property in that fiscal year.
The amount referred to in the first paragraph is equal to the amount by which the aggregate of the amounts referred to in subparagraphs a to h of paragraph 2 of the definition of “undepreciated capital cost” in the first paragraph of section 9, in respect of the class, exceeds the aggregate of the amounts referred to in subparagraphs a to d of paragraph 1 of the definition of that expression.