Corollary
Tag 06DT, permanent. Cite it as [Bourbaki, Tag 06DT].
Algebra, chapter IV, § 5. Symmetric tensors and polynomial mappings
— Assume that A is an infinite integral domain; let M be a free A-module and N a torsion-free A-module.
(i) We have and each may be identified canonically with .
(ii) Let and , a basis of M. There exists one and only one family of elements of N such that for all .
The assertion (i) follows from Prop. 16 and 19, and (ii) follows from (i) and the Cor. of Prop. 16.
Bourbaki puts the proof directly after the statement, so what is above is the statement and its proof together.