Definition 10.141.1. Let $\varphi : B' \to B$ be a ring map. We say $\varphi $ is a small extension if $B'$ and $B$ are local Artinian rings, $\varphi $ is surjective and $I = \mathop{\mathrm{Ker}}(\varphi )$ has length $1$ as a $B'$-module.
Definition 10.141.1. Let $\varphi : B' \to B$ be a ring map. We say $\varphi $ is a small extension if $B'$ and $B$ are local Artinian rings, $\varphi $ is surjective and $I = \mathop{\mathrm{Ker}}(\varphi )$ has length $1$ as a $B'$-module.
Comments (0)