Weiyuan, Qiu, Hausdorff Dimension of the M-Set of . exp(z), Acta Mathematica Sinica, New Series Chinese Journal of Mathematics, 10(4), 1994, pp. 362-368
We show that the set of . -values for which . exp(s) does not have stable regions has Hausdorff dimension two, and that the set of . -values for which . sin(z) does not have stable regions has a positive area.