360R23. The amount to be deducted from the aggregate determined in section 360R21 for a taxation year is the aggregate of the taxpayer’s losses for the year from a source described in paragraph b of section 360R21, as computed in accordance with the Act and assuming that the taxpayer had no other incomes or losses for the year than those from such source and that no deduction was granted in computing the taxpayer’s income for the year, other than(a) the amounts deductible under sections 362 to 394 of the Act, other than amounts that are foreign exploration and development expenses, or under section 88.4 of the Act respecting the application of the Taxation Act (chapter I-4), where the taxpayer has no gross resource profits from a natural accumulation, other than a mineral resource, of petroleum or natural gas in Canada, or an oil or gas well in Canada that is operated by the taxpayer and, in any other case, the part of those amounts that may reasonably be considered to be wholly attributable to a mineral resource in Canada;
(b) the amount by which the aggregate referred to in section 360R26 exceeds the incomes referred to in section 360R25;
(c) the amounts deductible or deducted, as the case may be, under any of sections 395 to 418.16, 418.18 to 418.36 and 419.5 of the Act for the year, other than amounts that are Canadian development expenses related to property described in paragraph b of section 370 of the Act that is a right, licence or privilege to store underground petroleum, natural gas or related hydrocarbons in Canada, where no amount is deducted under paragraph c of section 360R26 in computing the taxpayer’s gross resource profits for the year in respect of an oil business; and
(d) any other deduction attributable to a source of income described in paragraph b or c of section 360R21, other than a deduction under paragraph r or s of section 157 of the Act or under any of sections 360R17, 360R18, 360R30, 360R36, 360R82, 360R83 and 360R89.