On constant $U_q(sl_2)$-invariant $R$-matrices

The spectral resolution of a $U_q(sl_2)$-invariant solution $R$ of the constant Yang–Baxter equation in the braid group form is considered. It is shown that, if the two highest coefficients in this resolution are not equal, then $R$ is either the Drinfeld $R$-matrix or its inverse. Bibl. – 13 titles.