Bourbaki

Definition 6

Tag 076N, permanent. Cite it as [Bourbaki, Tag 076N].

Algebra, chapter VII, § 5. Endomorphisms of vector spaces

— Let E be a finite dimensional vector space over a commutative field K. Then an endomorphism u of E is said to be semi-simple if every subspace of E which is closed under u has a complement which is closed under u.

This means that every submodule of the K[X]K[X]-module E, is a direct factor, in other words the K[X]K[X]-module EuE_u is semi-simple (VII, p. 9).

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.