Formula_5401

\[\alpha_{n}\left(x_{1}, \ldots, x_{n}\right)=\delta W(a) / \delta a_{n}\left(x_{1}, \ldots, x_{n}\right)=\left\langle\varphi\left(x_{1}\right), \ldots, \varphi\left(x_{n}\right)\right\rangle,\]