F transpose(&matrix)
    V toRet = [[0] * matrix.len] * matrix[0].len
    L(row) (0 .< matrix.len)
        L(col) (0 .< matrix[row].len)
            toRet[col][row] = matrix[row][col]
    R toRet

V m = [[1, 2, 3, 4], [5, 6, 7, 8], [9, 10, 11, 12]]
print("Original")
print(m)
print("After Transposition")
print(transpose(&m))