ABSTRACT
We are interested in the general question: What can happen in the completion of a “nice” Noetherian ring? We are examining this question as part of a project of constructing Noetherian and non-Noetherian integral domains using power series rings. In this paper as a continuation of that project we display an example of a three-dimensional regular local domain An having a height-two prime ideal P with the property that the extension PA of P to the n-adic completion A of A is not integrally closed. The ring A in the example is a nested union of regular local domains of dimension five.
