“…However, in general, the convegence can be tangential or non-tangential and the cluster set of arg(1 − τ φ t (z)), as t → +∞, can be either a singleton {θ} or a set [θ 1 , θ 2 ], but it is always a compact connected subset of [− π 2 , π 2 ]. In [3,11] examples are constructed where the slope is the whole interval [− π 2 , π 2 ], while in [6,16] examples are constructed where the slope is a closed subinterval of (− π 2 , π 2 ). Furthermore, in [5], the authors find geometric conditions that guarantee that the slope reduces to {0}.…”