The following judgment of Chebyshev, from his paper "The drawing of geographical maps" ([B11], Vol. 5, pp. 150-157; Oeuvres, Vol. 1, pp. 239-247), is well-known: The majority of practical problems lead to maximum and minimum problems that are completely new to science, and only by solving those problems can we satisfy the requirements of practice, which always and everywhere seeks the best and most advantageous.