Corollary 2
Tag 0A88, permanent. Cite it as [Bourbaki, Tag 0A88].
Lie Groups and Lie Algebras, chapter III, § 1. Lie groups
Suppose that operates trivially on . Let be the trivial -bundle with base space and fibre . There exists one and only one isomorphism of onto compatible with the operations of and extending .
This follows immediately from Proposition 17.
Bourbaki puts the proof directly after the statement, so what is above is the statement and its proof together.