Remark (2)
Tag 053P, permanent. Cite it as [Bourbaki, Tag 053P].
Commutative Algebra, chapter VII, § 4. Modules over integrally closed Noetherian domains
In the statement of Theorem 5, the modules may be replaced by (, no. 4, Proposition 8). For all , the canonical mapping is a pseudo-isomorphism, as, for all distinct from , and .
\* Given an exact sequence of -modules, , if and are pseudo-zero, so is , as follows from Definition 2 and Chapter II, §2, no. 4, Theorem 1. In the language of categories, we may then say that, in the category of -modules, the sub-category of pseudo-zero modules is full and we may then define the quotient category : the objects in this category are also -modules but the set of morphisms from to (for in ) is the direct limit of the set of commutative groups , where (resp. ) runs through the set of submodules of (resp. the set of quotient modules of ) such that (resp. ) is pseudo-zero. Of course, for every ordered pair of -modules , there is a canonical homomorphism . To say that a homomorphism is pseudo-zero (resp. pseudo-injective, pseudo-surjective, pseudo-bijective) means that its canonical image in is zero (resp. a monomorphism, an epimorphism, an isomorphism). \*
Bourbaki puts the proof directly after the statement, so what is above is the statement and its proof together.