A graph is an apex graph if it contains a vertex whose deletion leaves a planar graph. The family of apex graphs is minor-closed and so it is characterized by a finite list of minor-minimal non-members. The long-standing problem of determining this finite list of apex obstructions remains open. This paper determines the 133 minor-minimal, non-apex graphs that have connectivity two.
翻译:图表是一个顶点图, 如果它包含一个顶点, 其删除会离开平面图。 顶点图的组别是小封闭的, 因此它的特征是少量非成员的有限清单。 确定顶点障碍物的有限清单的长期问题仍然未解决。 本文确定有两个连接点的133个微小、 非顶点图。