The paper considers non-negative increasing functions on intervals with left endpoint closed at zero and investigates the duality between subadditivity and superadditivity via the inverse function and pseudo-inverses. © 2005 Elsevier Inc. All rights reserved.
Østerdal, L. P. (2006). Subadditive functions and their (pseudo-)inverses. Journal of Mathematical Analysis and Applications, 317(2), 724–731. https://doi.org/10.1016/j.jmaa.2005.05.039