A remark on Vapnik-Chervonienkis classes
Agata Smoktunowicz (1997)
Colloquium Mathematicae
Similarity:
We show that the family of all lines in the plane which is a VC class of index 2 cannot be obtained in a finite number of steps starting with VC classes of index 1 and applying the operations of intersection and union. This confirms a common belief among specialists and solves a question asked by several authors.