Bourbaki

Proposition 2

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

Algebra, chapter II, § 4. Relations between tensor products and homomorphism modules

(i) When FF is a projective (resp. finitely generated projective) B-module, the canonical homomorphism (7) is injective (resp. bijective).

(ii) When EE is a finitely generated projective AA-module, the canonical homomorphism (7) is bijective.

(i) Fixing EE and GG, for every left BB-module FF, we write

T(F)=HomA(E,G)⊗BF,T′(F)=HomA(E,G⊗BF); T(F) = \mathrm{Hom}_A(E, G) \otimes_B F, \quad T'(F) = \mathrm{Hom}_A(E, G \otimes_B F);

for every left BB-module homomorphism u:F→F′u : F \to F', we write T(u)=1⊗uT(u) = 1 \otimes u (1 here denoting the identity mapping of HomA(E,G)\mathrm{Hom}_A(E, G)),

T′(u)=Hom(1E,1G⊗u); T'(u) = \mathrm{Hom}(1_E, 1_G \otimes u);

on the other hand we write νF\nu_F instead of ν\nu. Then we have the following lemmas:

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

Cited by

Cites

Nothing.

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