3.25 VC-dimension of symmetric dierence of concepts. For two sets A and B, let A
B denote the symmetric dierence of A and B, i.e., A
B = (A[B)????(A\B).

Let H be a non-empty family of subsets of X with nite VC-dimension. Let A be an element of H and dene H
A = fX
A: X 2 Hg. Show that VCdim(H
A) = VCdim(H):