This work formalizes the problem of minimizing memory consumption through recomputation when performing a forward-backprop evaluation of a computation graph; it provides an optimal dynamic programming algorithm and an efficient heuristic and demonstrates strong improvements in memory savings over existing methods. Three expert reviewers initially assess the paper as 8/8/5, and the authors provided a detailed rebuttal. All reviewers took part in a discussion and the final assessment is 8/8/6, with reviewer consensus that this method is practically useful and the reported gains are strong. Overall this work is a nice contribution.