# 导出函子就是 Kan 延拓　`prop.derived-functor-kan-extension`
命题：$F$ 左正合 $\implies RF$ 是沿局部化的左 Kan 延拓
layer 14 · 命题 · 复形与导出三角 · 同调代数
[在星图里打开](../#n=prop.derived-functor-kan-extension)　·　[节点索引](../index.md)

设 $F : \mathcal{A} \to \mathcal{A}'$ 是**左正合**加法函子。则 $RF$ 是复合映射
> 陈述续见 [nodes/prop.derived-functor-kan-extension.2.md](./prop.derived-functor-kan-extension.2.md)


## 为什么成立（入边，证明在 proofs/）
- …另有入边，续页见 [nodes/prop.derived-functor-kan-extension.3.md](./prop.derived-functor-kan-extension.3.md)

refs: Le Stum, An introduction to condensed mathematics, Exercise 7.22

> 说明见 `notes/prop.derived-functor-kan-extension.md`

引用：`prop.derived-functor-kan-extension`（内容 v0.9.0）· 条款见 [LICENSE.txt](../LICENSE.txt)