The Sauer-Shelah lemma states that if , then
In particular, the Sauer-Shelah growth bound gives .
If is shattered by , then all label vectors belong to the union of the label-vector sets generated by the individual classes. The shattering coefficient of a union and the Sauer-Shelah lemma therefore give
Taking base-two logarithms yields
For , apply the stated elementary bound with and :
If , the assertion follows directly from . Taking the largest shattered sample size proves
For a binary function class , the shattering coefficient is
Its VC dimension is the largest for which , with value infinity if there is no largest such . The Sauer-Shelah lemma states that, when ,