Corollary

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

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

An element $x \in C$ if and only if $x > w(x)$ for all $w \in W$ such that $w \neq 1$ .

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

Cited by

Nothing.