[M, N] -> { S2[i0] -> [2M + i0] : i0 >= 1 and i0 <= N; S1[i0] -> [M + i0] : i0 >= 1 and i0 <= N }
[M, N] -> {  : N >= M and M >= 2 }
[M, N] -> { [i] -> separate[o0] }