Proposition 1
Tag 08NR, permanent. Cite it as [Bourbaki, Tag 08NR].
Integration, chapter III, § 3. Integrals of continuous vector-valued functions
— The mapping
of into is bilinear.
The proposition follows immediately from Def. 1 of No. 1.
Let be a continuous linear mapping of into a locally convex space ; we know that the transpose is a linear mapping of the dual of into the dual of ; we shall denote by the mapping , the transpose of (in the algebraic sense); when and are Hausdorff and are canonically identified with subspaces of and , respectively, extends the mapping . With these notations:
Bourbaki puts the proof directly after the statement, so what is above is the statement and its proof together.