 $$\frac{\partial L(..)}{\partial y^{\nu ..}\,_{\!|..}}\, - \Delta_b^{\scsc\#} \left\{\left[ \frac{\partial L(..)}{\partial y_b^{\nu ..}}\right]_{|..}\right\} - \partial_t \left\{\left[ \frac{\partial L(..)}{\partial 