If f (x) is a noninvertible endomorphism of a formal group, then we have that f (x) commutes with an invertible series and Ō[[x]] is Galois over Ō[[fn(x)]] for all n ∈ N. We shall prove that the converse of this statement is also true.
|頁（從 - 到）||2325-2329|
|期刊||Proceedings of the American Mathematical Society|
|出版狀態||已發佈 - 1996|
ASJC Scopus subject areas