Local level sets of the Takagi-van der Waerden function

Lai Jiang, Ting-Ting Ying, Yi-Yang Zhang

In this paper, we investigate the Takagi-van der Waerden function, $$T_r(x)=\sum _{n=0}^{\infty }\frac{\ddot{I}•(r^{n}x)}{r^n},x\in [0,1],r\in {\mathbb{Z}}^{+},$$ where $ϕ(x…