FORMAL POWER-SERIES RINGS OVER ZERO-DIMENSIONAL SFT-RINGS

Let R be a sere-dimensional SET-ring. It is proved that the minimal pr ime ideals of the formal power series ring A = R[[x(1), ..., x(n)]] ar e the ideals of the form M[[x(1), ..., x(n)]] where M is a (minimal) p rime of R. It follows that A has Krull dimension n and is catenarian. If R subset of or equal to T where T is also a zero-dimensional SFT-ri ng, the lying-over, going-up,incomparable, and going-down properties a re studied for the extension A subset of or equal to T[[x(1), ..., x(n )]].