OAI/AlgebraicGeometry/CartierSections/RetractionBounds.lean

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2 declarations, 0 contain sorry, 0 declared as axioms

Valuation inequalities for monomial retractions

In a closed étale chart, monomial retraction decreases the values of regular functions. The inequality passes to the valuation of the fraction field.

  1. lemma OAI.CartierSections.closedChartRetraction_le line 32

    Source documentation

    Retraction decreases all regular-function values in a Noetherian closed étale chart, including boundary faces with zero weights.

    lemma closedChartRetraction_le [CharZero k]
        (v : AddValuation A ENNReal) (B : Finset σ) (w : σ → ℝ≥0)
        (hwzero : ∀ i ∉ B, w i = 0)
        (hz : ∀ i ∈ B, v (algebraMap (MvPolynomial σ k) A (MvPolynomial.X i)) =
          (w i : ENNReal)) (f : A) : closedChartRetraction (σ := σ) (k := k) (A := A) (R := R) w f ≤ v f := by
    …

    Mentions: OAI.CartierSections.closedChartRetraction

  2. lemma OAI.CartierSections.closedChartFieldRetraction_le line 82