Gamkrelidze's own 2003 account divides the 1956 maximum-principle discovery into three named, distinct technical contributions

gamkrelidzepontryaginboltyanskiimaximum-principleoptimal-controlsoviet-unioncredit-attributionhistory-of-mathematicsneedle-variations

R.V. Gamkrelidze's 2003 chapter "Discovery of the Maximum Principle in Optimal Control" — a first-person historical account republished in at least four venues across two decades — describes the 1956 breakthrough as proceeding in distinct, named stages rather than as undifferentiated group work. Pontryagin made the opening move alone, introducing the adjoint covector system "during three days, or better to say, during three consecutive sleepless nights," before inviting Gamkrelidze and V.G. Boltyanskii, his former students, to join him. The group then split the work by direction: Pontryagin and Boltyanskii pursued controllability; Gamkrelidze investigated the second variation, which "led to the final formulation of the maximum principle." Pontryagin then generalized Gamkrelidze's local result into the global maximum condition. A fourth, separate technical step was still required for the general-case proof, credited explicitly to Boltyanskii alone: his invention of "needle variations" of the control function, without which the maximum principle could not be proved in full generality.

This is a specific, named three-way division of technical labor, in the words of one of the three collaborators — more granular than the vault's prior undifferentiated record ("Pontryagin, with Boltyanskii, Gamkrelidze, and Mishchenko, formulated the maximum principle," on entity-lev-pontryagin). It is consistent with the same seminar context the vault already documents in claim-feldbaum-lerner-seminar-input-catalyzed-pontryagin-maximum-principle and claim-pesch-plail-2012-frames-cold-war-optimal-control-as-blue-red-corners.