i1 : A = typeA(3) o1 = A o1 : Hyperplane Arrangement
i2 : flats(2,A) o2 = {{0, 1, 3}, {0, 2, 4}, {0, 5}, {1, 4}, {1, 2, 5}, {2, 3}, {3, 4, 5}} o2 : List