flat module
平坦模
Meaning in context
A module over a commutative ring for which tensoring preserves every short exact sequence.
在交换环上,与之张量的函子保持所有短正合列的模。
Example
is flat over .
Usage and distinctions
Flatness requires exact tensoring, not finite generation or existence of a basis.
Recommended reading in this subject · Preparation & skip guidance
Definition sources
- Wen-Wei Li — Methods in Algebra I, author source投射模, 内射模, 平坦模, unnamed definition of 平坦模 immediately after def:inj-proj-modules, exact tensor functor; commutative-ring specialization · Checked 2026-10-15
Translation sources
- 李文威 — 代数学方法 卷一,作者源文件投射模, 内射模, 平坦模, unnamed definition of 平坦模 immediately after def:inj-proj-modules, exact tensor functor; commutative-ring specialization · Checked 2026-10-15