# 新的考虑

#### *今日博主*：徐令予李颖业张忆文林中祥张云李学宽宁利中蒋迅蒲亨建刘全慧韩健毛宏王庆浩尤明庆张操张忆文曾新林文克玲蔡宁吕洪波杨正瓴彭真明蒋继平姬扬徐耀刘钢刘全生吕喆王鸿飞陈儒军马臻刘进平赵美娣鲍永利戴世强周涛刘洋邢志忠 曾泳春郭景涛余国志（保留若干神秘博主）

normal variety*In algebraic geometry, an algebraic variety or scheme X  is normal if it is normal at every point, meaning that the local ring at the point is an integrally closed domain

.

.

In practice, a commutative local ring often arises as the result of the localization of a ring at a prime ideal.

.

ring R is a local ring if it has any one of the following equivalent properties:

• R has a unique maximal left ideal.

• R has a unique maximal right ideal.

• 1 ≠ 0 and the sum of any two non-units in R is a non-unit.

• 1 ≠ 0 and if x is any element of R, then x or 1 − x is a unit.

• If a finite sum is a unit, then it has a term that is a unit (this says in particular that the empty sum cannot be a unit, so it implies 1 ≠ 0).

.

#### *今日博主*：徐令予李颖业张忆文林中祥张云李学宽宁利中蒋迅蒲亨建刘全慧韩健毛宏王庆浩尤明庆张操张忆文曾新林文克玲蔡宁吕洪波杨正瓴彭真明蒋继平姬扬徐耀刘钢刘全生吕喆王鸿飞陈儒军马臻刘进平赵美娣鲍永利戴世强周涛刘洋邢志忠 曾泳春郭景涛余国志（保留若干神秘博主）

http://blog.sciencenet.cn/blog-315774-1130650.html

## 全部精选博文导读

GMT+8, 2020-9-23 11:43