Some notes on the switching points for the generalized Hukuhara differentiability of interval-valued functions

In this paper, we give some comments on the recent results about the switching points for the gH-differentiability of interval -valued functions. We show by counterexamples that there exist switching points which are not critical points of the length function, and that there are GH-differentiable functions with an infinite number of switching points and gH-differentiable functions with an uncountable number of switching points. After reclassifying the switching points more finely, we also present some characteriza-tions for the switching points. The obtained results correct the known ones in the literature.(c) 2022 Elsevier B.V. All rights reserved.