A remark on Vapnik-Chervonienkis classes
Volume 74 / 1997
Colloquium Mathematicum 74 (1997), 93-98
DOI: 10.4064/cm-74-1-93-98
Abstract
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.