(2) In such formula: (A) “A” is the amount the United States is entitled to recover. (B) “Φ” is the sum of— (i) the amounts paid under this subchapter to or on behalf of the participant; and (ii) the interest on such amounts which would be payable if at the time the amounts were paid they were loans bearing interest at the maximum legal prevailing rate, as determined by the Treasurer of the United States. (C) “t” is the total number of months in the participant’s period of obligated service, including any additional period of obligated service in accordance with section 7673(c)(2) of this title . (D) “s” is the number of months of such period served by the participant in accordance with section 7673 of this title .
38 USC § 7675(c)(2)
None identified, default scope is assumed to be the parent (subchapter VI) of this section.