A simple proof of a well-known monotonicity theorem for the approximate derivative is presented. The same technique provides a proof of a generalized version of Ornesteinʼs Theorem.
"A Note on Monotonicity Theorems for Approximately Continuous Functions." Real Anal. Exchange 42 (2) 429 - 432, 2017. https://doi.org/10.14321/realanalexch.42.2.0429