prior taxable year (or years)
(ii) For purposes of applying section 1341(b)(4)(B) in computing the amount of the decrease referred to in paragraph (b)(1)(ii) of this section for any taxable year beginning after December 31, 1961, the term prior taxable year (or years) includes the taxable year of restoration. Under section 1341(b)(4)(B), for taxable years of restoration beginning after December 31, 1961, in any case where the exclusion referred to in section 1341(a)(5)(B) and paragraph (b)(1)(ii) of this section results in a net operating loss or capital loss for the prior taxable year (or years), such loss shall, for purposes of computing the decrease in tax for the prior taxable year (or years) under such section 1341(a)(5)(B) and such paragraph (b)(1)(ii) of this section, be carried back and carried over to the same extent and in the same manner as is provided under section 172 (relating to the net operating loss deduction) or section 1212 (relating to capital loss carryover), except that no carryover beyond the taxable year shall be taken into account. See subparagraph (4) of this paragraph for rules relating to the computation of the amount of decrease in tax. (2) Amount of exclusion from gross income in prior taxable years. (i) The amount to be excluded from gross income for the prior taxable year (or years) in determining the decrease in tax under section 1341(a)(5)(B) and paragraph (b)(1)(ii) of this section shall be the amount restored in the taxable year, but shall not exceed the amount included in gross income in the prior taxable year (or years) under the claim of right to which the deduction for the restoration is attributable, and shall be adjusted as provided in subdivision (ii) of this subparagraph. (ii) If the amount included in gross income for the prior taxable year (or years) under the claim of right in question was reduced in such year (or years) by a deduction allowed under section 1202 (or section 117 (b) of the Internal Revenue Code of 1939 or corresponding provisions of prior revenue laws), then the amount determined under subdivision (i) of this subparagraph to be excluded from gross income for such year (or years) shall be reduced in the same proportion that the amount included in gross income under a claim of right was reduced. (iii) The determination of the amount of the exclusion from gross income of the prior taxable year shall be made without regard to the capital loss limitation contained in section 1211 applicable in computing taxable income for the current taxable year. The amount of the exclusion from gross income in a prior taxable year (or years) shall not exceed the amount which would, but for the application of section 1211, be allowable as a deduction in the taxable year of restoration. (iv) The rule provided in subdivision (iii) of this subparagraph may be illustrated as follows: (3) Determination of amount of deduction attributable to prior taxable years. (i) If the deduction otherwise allowable for the taxable year relates to income included in gross income under a claim of right in more than one prior taxable year and the amount attributable to each such prior taxable year cannot be readily identified, then the portion attributable to each such prior taxable year shall be that proportion of the deduction otherwise allowable for the taxable year which the amount of the income included under the claim of right in question for the prior taxable year bears to the total of all such income included under the claim of right for all such prior taxable years. (ii) The rule provided in subdivision (i) of this subparagraph may be illustrated as follows: (4) Computation of amount of decrease in tax. (i) In computing the amount of decrease in tax for a prior taxable year (or years) resulting from the exclusion from gross income of the income included under a claim of right, there must first be ascertained the amount of tax previously determined for the taxpayer for such prior taxable year (or years). The tax previously determined shall be the sum of the amounts shown by the taxpayer on his return or returns, plus any amounts which have been previously assessed (or collected without assessment) as deficiencies or which appropriately should be assessed or collected, reduced by the amount of any refunds or credits which have previously been made or which appropriately should be made. For taxable years beginning after December 31, 1961, if the provisions of section 1341(b)(4)(B) are applicable, the tax previously determined shall include the tax for the taxable year of restoration computed without taking the deduction for the amount of the restoration into account. After the tax previously determined has been ascertained, a recomputation must then be made to determine the decrease in tax, if any, resulting from the exclusion from gross income of all or that portion of the income included under a claim of right to which the deduction otherwise allowable in the taxable year is attributable. (ii) No item other than the exclusion of the income previously included under a claim of right shall be considered in computing the amount of decrease in tax if reconsideration of such other item is prevented by the operation of any provision of the internal revenue laws or any other rule of law. However, if the amounts of other items in the return are dependent upon the amount of adjusted gross income, taxable income, or net income (such as charitable contributions, foreign tax credit, deductions for depletion, and net operating loss), appropriate adjustment shall be made as part of the computation of the decrease in tax. For the purpose of determining the decrease in tax for the prior taxable year (or years) which would result from the exclusion from gross income of the item included under a claim of right, the exclusion of such item shall be given effect not only in the prior taxable year in which it was included in gross income but in all other prior taxable years (including the taxable year of restoration if such year begins after December 31, 1961, and section 1341(b)(4)(B) applies, see subparagraph (1)(ii) of this paragraph) affected by the inclusion of the item (for example, prior taxable years affected by a net operating loss carryback or carryover or capital loss carryover). (iii) The rules provided in this subparagraph may be illustrated as follows: