x/6 as the first base term.  Then, x can be written as
    (x/2) * 2, so we get (0, 2), and so on. Now only element (x**2 + 1)
    remains, and there are no other terms that can be written as a rational
    multiple of that, so we get that it can be written as (x**2 + 1) * 1.

    c