Bourbaki

Corollary

Tag 0AVV, permanent. Cite it as [Bourbaki, Tag 0AVV].

Lie Groups and Lie Algebras, chapter VI, § 1. Root systems

*Let P, P′P' be two parabolic subsets of R transformed into each other by an element of the Weyl group. If there exists a chamber C of R such that R+(C)⊆PR_+(C) \subseteq P and R+(C)⊆P′R_+(C) \subseteq P', then P=P′P = P'.

This follows from Lemma 3 and Prop. 21 since the only element of W(R)W(R) transforming C to C is 1, cf. no. 5, Th. 2.

Bourbaki puts the proof directly after the statement, so what is above is the statement and its proof together.

Cited by

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Cites

Transcribed from the printed volume. Not translated.