Fractal analysis for sets of non-differentiability of Minkowski's question mark function

In this paper we study various fractal geometric aspects of the Minkowski question mark function Q  . We show that the unit interval can be written as the union of the three sets Λ0:={x:Q′(x)=0}, Λ∞:={x:Q′(x)=∞}, and Λ∼:={x:Q′(x) does not exist and Q′(x)≠∞}. The main result is that the Hausdorff dimensions of these sets are related in the following way:dimH(νF)