Curves which Intersect Lines in Finite Sets
Robbert Fokkink · Bulletin of the London Mathematical Society · 2001
We study closed subsets in the plane which intersect each line in at least m points and at most n points, for which we try to minimize the difference n − m. It is known that m cannot be equal to n. The results in this paper show that for every even number n there exist closed sets in the plane for which m = n − 2.