Formula_13850

\[\begin{gathered}R_{\alpha \beta \gamma \delta}=R_{\alpha \gamma} g_{\beta \delta}-R_{\alpha \delta} g_{\beta \gamma}+R_{\beta \delta} g_{\alpha \gamma}-R_{\beta \gamma} g_{\alpha \delta}+ \\+\frac{g^{\varepsilon \xi} R_{\varepsilon \xi}}{2}\left(g_{\alpha \delta} g_{\beta \gamma}-g_{\alpha \gamma} g_{\beta \delta}\right),\end{gathered}\]