Intersections of vertical lines with non-vertical lines
Mateusz Kula
所有作者
Mateusz Kula
文献摘要
We answer negatively a question: if F is a family of n⩾3 non-vertical, pairwise non-parallel lines on the plane and ⋂F=∅, is there a vertical line L such that L∩⋃F has exactly n−1 or n−2 points?