> Z ring enriched (if this is right word) with sqrt(5) I think "extended" is the right word (see http://en.wikipedia.org/wiki/Ring_extension http://en.wikiped

> Z ring enriched (if this is right word) with sqrt(5) I think "extended" is the right word (see http://en.wikipedia.org/wiki/Ring_extension http://en.wikipedia.org/wiki/Ring_extension) It is commonly denoted as Z[sqrt(5)]