 $$\begin{aligned}         B_{s,\varepsilon} & = \int_s^{s+\varepsilon} \frac{\partial f}{\partial x}(s,x_s)\psi_u\delta R_u^H \\         & \hspace{0cm} + 0c_H^{B,R}\int_s^{s+\varepsilon}\left[\frac{\partial f}{\partial x}(s,x_s)\