assumed CSRS annuity
(5) For the purpose of this subsection, the term “assumed CSRS annuity”, as used in the case of a survivor, means the amount of the annuity to which such survivor would be entitled under subchapter III of chapter 83 of this title based on the service of the deceased annuitant, determined— (A) as of the day after the date of the annuitant’s death; (B) as if the survivor had made appropriate application therefor; and (C) as if the service of the deceased annuitant were creditable under such subchapter.