Constrained partitioning problems (Q5906520)

\textit{R. E. Burkard} and \textit{E. Yao} [Discrete Appl. Math. 28, No. 1, 21- 34 (1990; Zbl 0734.05030) and Discrete Appl. Math. 46, No. 2, 185 (1993; Zbl 0783.05035)] studied matroid-constrained optimal partitioning problems and gave a sufficient condition to the applicability of an algorithm. Here the authors show that their condition is not necessary, and give an alternative sufficient condition as well.