[FOM] UFD example?

[Wayne Aitken]

On 11/17/07 6:38 PM, "joeshipman at aol.com" <joeshipman at aol.com> wrote:

> What is an example of Unique Factorization Domain which is neither a
> Principal Ideal Domain nor (isomorphic to) a polynomial ring? (By a
> polynomial ring I mean a ring R[x] formed by adjoining an indeterminate
> to a ring; such rings are UFDs if the original ring was, by the
> generalized Gauss Lemma).
> 


The ring of formal power series F[[x_1, \ldot, x_n]] with n>1.