That proportion of the deductions specified in sections 2053 and 2054 (other than the deductions described in the following sentence) which the value of such part bears to the value of his entire gross estate, wherever situated. Any deduction allowable under section 2053 in the case of a claim against the estate which was founded on a promise or agreement but was not contracted for an adequate and full consideration in money or money’s worth shall be allowable under this paragraph to the extent that it would be allowable as a deduction under paragraph (2) if such promise or agreement constituted a bequest.
If the tax imposed by section 2101, or any estate, succession, legacy, or inheritance taxes, are, either by the terms of the will, by the law of the jurisdiction under which the estate is administered, or by the law of the jurisdiction imposing the particular tax, payable in whole or in part out of the bequests, legacies, or devises otherwise deductible under this paragraph, then the amount deductible under this paragraph shall be the amount of such bequests, legacies, or devises reduced by the amount of such taxes.
The provisions of section 2055(e) shall be applied in the determination of the amount allowable as a deduction under this paragraph.
The amount which bears the same ratio to the State death taxes as the value of the property, as determined for purposes of this chapter, upon which State death taxes were paid and which is included in the gross estate under section 2103 bears to the value of the total gross estate under section 2103. For purposes of this paragraph, the term “State death taxes” means the taxes described in section 2058(a).
No deduction shall be allowed under paragraphs (1) and (2) of subsection (a) in the case of a nonresident not a citizen of the United States unless the executor includes in the return required to be filed under section 6018 the value at the time of his death of that part of the gross estate of such nonresident not situated in the United States.