Bourbaki

Definition 1

Tag 05N2, permanent. Cite it as [Bourbaki, Tag 05N2].

Algebra, chapter II, § 2. Modules of linear mappings. Duality

An A-module P is called projective if, for every exact sequence F' → F → F'' of A-linear mapping, the sequence

Hom⁡(P,F′)→Hom⁡(P,F)→Hom⁡(P,F′′) \operatorname{Hom}(P, F') \to \operatorname{Hom}(P, F) \to \operatorname{Hom}(P, F'')

is exact.

Bourbaki puts the proof directly after the statement, so what is above is the statement and its proof together.

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Cites

Nothing.

Transcribed from the printed edition, 1998, Springer. Not translated.