We study two notions of fan-planarity introduced by (Cheong et al., GD22), called weak and strong fan-planarity that separate two non-equivalent definitions of fan-planarity in the literature. We prove that not every weakly fan-planar graph is strongly fan-planar, while the density upper bound for both families is the same.

翻译：我们研究了(Cheong等, GD22)提出的两种扇形平面性概念，即弱扇形平面性和强扇形平面性，它们区分了文献中两种不等价的扇形平面性定义。我们证明了并非所有弱扇形平面图都是强扇形平面图，而这两个图族的上界密度相同。