Given positive integers a₁, a₂, …, a_n, b, a feasible subset is as follows.
Question: How many are the feasible subsets?
So U = 2^N, V is the set of feasible subsets. Sampling uniformly in U is easy, just generate randomly 0-1 values with probability 1/2 for i :=1,2,..., n.
However there are problems: p cannot be polynomially bounded. Instances of the type a_i := a, "i, b := 3a, we have as follows.