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\begin{LTR}
\begin{document}\begin{itemize}
 \item[\rm(i)]$\dim{\cal M}(L, N)+\dim\gamma_{c}(N, L)\leq \dim{\cal M}(\frac{L}{\gamma_{c}(N, L)}, \frac{N}{\gamma_{c}(N, L)})$\\
 ~~~~~~~~~~~~~~~~$+\dim((\dfrac{L}{Z_{c-1}(N, L)})_{ab}\otimes (\gamma_c(N, L))_{ab});$
 \item[\rm(ii)]$dim({\cal M}(L, N))+dim\gamma_2(N, L)\leq dim({\cal M}(\frac{L}{\gamma_2(N, L)},\frac{N}{\gamma_2(N, L)})\\+\displaystyle\sum_{i=1}^{c-1}dim((\frac{L}{\gamma_{i+1}(N, L)})_{ab}\otimes (\gamma_{i+1}(N, L))_{ab});$
\end{itemize}
\end{LTR}
\end{document}