{\cal P} & = & \{f_1, f_2, \ldots, f_m\} \ {\cal C} & = & \{c_1, c_2, \ldots, c_m\} \ {\cal N} & = & \{n_1, n_2, \ldots, n_m\}

\cal A, B, C, D, E, F, G, H, I, J, K, L, M, \ \cal N, O, P, Q, R, S, T, U, V, W, X, Y, Z

\sum_{i_1, i_2, \ldots, i_n} \pi * i + \sigma

-- Main.winckler - 2013-10-14