we propose to minimize (8) with grid points between λ1= t/x(1)and λn= t/x(n)and step S = t/x(i), with i ∈ s. We considerthe step S = t/x(i)because δ(·) is a step function and δ(xi≤ x(j)) = δ(xi≤ a) for all a within the interval [x(j), x(j+1))according to assumption (A2).Let λk= t/x(k)be the value that minimizes (8) and let m be the number of values xi, with i ∈ U, within the interval [x(k),x(k+1)). Since (8) is defined at the sample level, it is clear that λi= t/xi, with i ∈ U and xi∈ [x(k), x(k+1)), also minimize(8), and m solutions are thus obtained. For this reason, we propose to use into (11) the value λrthat minimizes