On Whitney-type characterization of approximate differentiability on   metric measure spaces
  We study approximately differentiable functions on metric measure spaces admitting a Cheeger differentiable structure. The main result is a Whitney-type characterization of approximately differentiable functions in this setting. As an application, we prove a Stepanov-type theorem and consider approximate differentiability of Sobolev, BV and maximal functions. 
Estibalitz Durand-Cartagena, Lizaveta Ihnatsyeva, Riikka Korte, Marta   Szuma\'nska
math.CA