[M, N] -> { S1[i0, i1] -> [i0, i1, 0] : (i0 >= 1 and i0 <= N and i0 >= M and i1 >= 1 and i1 <= M) or (i0 >= 1 and i0 <= N and i0 <= 2M and i1 >= 1 and i1 <= M) }
[M, N] -> {  :  }
[M, N] -> { [i, j, k] -> separate[o0] }