Consider the following subsets of rational numbers, countable and dense in $[a,b]$ $T_1=\left\{\left.a<\frac{M_1(n_1)}{R_1(q_1)}<b\right|n_1,q_1\in\mathbb{Z}\right\}$ $,T_2=\left\{\left.a<\frac{M_2(n_2)}{R_2(q_2)}<b\right|n_2,q_2\in\mathbb{Z}\right\},...,$ $T_m=\left\{\left.a<\frac{M_m(n_m)}{R_m...