But the average Japanese does not own a car (as an individual). I don't have the figures but someone told me that less than half of those of driving age do not own a car, moreso, of those who do have a license, a relatively small percentage of those with licenses own their own car, many are paper drivers.

As usual, it is simpler to begin by looking at a more general setting—in this case, commutative rings—before getting involved with polynomial rings. It turns out that the nature of the ideals in a commutative ring is important: for example, we have already seen that gcd's exist in PIDs, while this may not be true in other commutative rings.

It makes use of two new reddening-free concepts: a distance indicator called pseudomagnitude, and a quasi-experimental observable that is independent of distance and specific to each star, called the differential surface brightness (DSB).

The scientists repeated the experiment in order to confirm the result.