Proposition 3
Tag 09IP, permanent. Cite it as [Bourbaki, Tag 09IP].
Integration, VIII, p. 11, § 2. Linear representations of groups
(i) If U is separately continuous, then is separately continuous when E' is equipped with the weak topology . (ii) If G is locally compact and U is continuous, then is continuous when E' is equipped with the topology of compact convergence.
The assertion (i) is immediate. The assertion (ii) follows from Lemma 3 where one has taken .
Bourbaki puts the proof directly after the statement, so what is above is the statement and its proof together.