Corollary 1
Tag 06T0, permanent. Cite it as [Bourbaki, Tag 06T0].
Algebra, chapter V, § 14. Transcendental extensions
— Suppose that E is a finitely generated extension of K, and let be the relative algebraic closure of K in E (V, p. 19). Then is of finite degree over K.
Let B be a transcendence basis of E over K. By Cor. 2 of V, p. 114, is linearly disjoint from over K, whence and now the finiteness of follows from that of .
Bourbaki puts the proof directly after the statement, so what is above is the statement and its proof together.