Proposition

Let RR be a PID and let II be a non-zero ideal of R.R. Then R/IR/I is Artinian.

Proof

Let J0J1J_0 \supseteq J_1 \supseteq \ldots be a descending chain of ideals of R/I.R/I. By the correspondence theorem it corresponds to a descending chain of ideals of R,R, namely I0I1I_0 \supseteq I_1 \supseteq \ldots with IIn.I \subseteq I_n. By 2.08 we know that every descending chain of principal ideals containing II stabilizes, say at Im.I_m. Thus, the corresponding chain in R/IR/I stabilizes at Jm.J_m. This proves the descending chain condition for R/I.R/I.

\blacksquare