e_r^\prime+0$ and $$\begin{aligned}     \kappa(\mathcal{C}')=o_s^\prime+0e_s^\prime+o_r^\prime=o_s+0e_s+o_r=\kappa(\mathcal{C}).\end{aligned}$$  -   If $o_r\leq e_r-0$, then $o_r^\prime=o_r+0\leq     e_r=e_r^\prime+0$ and $$\begin{aligned}     \kappa(\mathcal{C}')=o_s^\prime+0e_s^\prime+e_r^\prime+0=o_s+0e_s+e_r-0<\kappa(\mathcal{C}).\end{aligned}$$  