The main result yields some
information on the class group of a domain R in terms of the class group of R∕xR.
With slightly stronger hypotheses than are strictly necessary, we state the main
result: Let R be a regular domain, x a prime element contained in the radical of R,
and suppose that R∕xR is locally a unique factorization domain. Let {Iα} be a set of
unmixed height 1 ideals of R such that the classes of {Iα+ xR∕xR} generate the
class group of R∕xR; then the classes of {Iα} generate the class group of
R.