The best one-sided approximation of one class of functions by another

We concern ourselves with problems of the best one-sided approximation of classes of continuous functions. We obtain estimates of the best one-sided approximation of one class of functions by another, and we find exact values of the upper bounds of the best one-sided approximations on the classes $H_\omega$ of $2\pi$-periodic functions [given by an arbitrary convex modulus of continuity $\omega(t)$] by trigonometric polynomials of order not higher than $n-1$ in the $L_{2\pi}$ metric.