Assume that \(s_1,\dots, s_n\) are natural numbers. There are at most \(n+ \sum s_i\) sequences \((a_1,\dots, a_n)\) with \(0\leq a_i\leq s_i\) such that if \((a_1,\dots, a_n)\), \((b_1,\dots, b_n)\) are two of them then either \(a_i\leq b_i\) holds for every \(i\), or vice versa, or \(a_i b_i= 0\) holds for every \(i\).