“…Let us callũ n i := u n i − U n i (similarly forṽ n i ) and take the maximum ofũ n i among all nodes of the star, that is,ũ n := max i=0,...,s |ũ n i |. Then, after some straightforward computations (the reader may see [2] for further details of the computations) together with the Mean Value Theorem applied to the functions f (λ) = (λ) δ , δ = m, α, we arrive to the following…”