Corollary
Tag 09SU, permanent. Cite it as [Bourbaki, Tag 09SU].
Integration, chapter IX, § 6. Promeasures and measures on a locally convex space
— Let F be a barreled nuclear space, a locally convex topology on intermediate to and , a promeasure on , and the Fourier transform of . For to be a measure, it is necessary and sufficient that be continuous on F.
Necessity follows from Prop. 9 of No. 8 and sufficiency from Th. 2.
Bourbaki puts the proof directly after the statement, so what is above is the statement and its proof together.