Bourbaki

Corollary 4

Tag 04YI, permanent. Cite it as [Bourbaki, Tag 04YI].

Commutative Algebra, chapter VI, § 10. Extensions of a valuation to a transcendental extension

Suppose that v is improper (in which case k=Kk = K). Then

h(Γ′)+d(k′/K)≤r(Γ′)+D(k′/K)≤d(K′/K). h(\Gamma') + d(k'/K) \leq r(\Gamma') + D(k'/K) \leq d(K'/K).
If, in particular, v' is of height 1, then
d(k′/K)≤d(K′/K)−1; d(k'/K) \leq d(K'/K) - 1;
further, if K′K' is a finitely generated extension of KK and there is equality in (12), then v′v' is a discrete valuation and k′k' is a finitely generated extension of KK.

It is a series of special cases of Corollaries 1, 2, 3.

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

Cited by

Nothing.

Cites

Nothing.

Transcribed from the printed volume. Not translated.