Formula_15194

\[\begin{gathered}S_{T_{1} T_{2}}(\varphi)=S_{T_{1}}^{T_{2}} \frac{1}{2} \sum_{i, j} a_{i j}(\varphi(t))\left(\varphi^{i}(t)\right)- \\-b^{i}(\varphi(t))\left(\varphi^{j}(t)\right)-b^{j}(\varphi(t))\end{gathered}\]