“…Let (e0, e,,..., eq) be a (a+l)-tuple with elements equal to ± 1 and let {k,}U0 t>e a fixed set ofq+l integers satisfying 0<ko<k,< ■ -■ <kq^n-1. "Monotone approximation" in C [a,b] by the set N={pePn_1; etp^'W^Q on [a, b], i = 0, 1,..., a} has been studied by O. Shisha [13], G. G. Lorentz and K. L. Zeller [6], R. A. Lorentz [7], and J. A. Roulier [10].…”