A Comment on: F.K. Hwang, Y.M. Wang and J.S. Lee, ‘Sortability of Multi-Partitions’, Journal of Global Optimization 24 (2002), pp. 463–472

We correct a claim, made in [6], that the proof of the key result in [3] about the existence of a monotone optimal multi-partition was incomplete; further, we provide a sortability interpretation for the criticized step of that proof.