Bourbaki

Corollary 1

Tag 0736, permanent. Cite it as [Bourbaki, Tag 0736].

Algebra, chapter VII, § 3. Free modules over a principal ideal domain

— If every left ideal of AA is projective, then every submodule of a projective left AA-module is projective.

Indeed every projective AA-module is a submodule of a free AA-module (II, p. 231, Prop. 4), and Th. 1 applies.

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

Cited by

Nothing.

Cites

Transcribed from the printed edition, 2003, Springer. Not translated.