Module

ProjSpaceCech_GradedModule_finite_cohomology_pi_FD.lean

Nyll.SchemeTheory.Cohomology.Cech.ProjSpaceCech_GradedModule_finite_cohomology_pi_FD
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Finite Cech cohomology of a finite product of shifted free graded modules.

Declarations

ProjSpaceCech.GradedModule.finite_cohomology_pi_FD
Source context 5 commands

Surrounding namespaces, section variables, and local commands at this declaration.

section ProofImplementation
namespace AlgebraicCurves.Cohomology.Cech.Proofs.ProjSpaceCech_GradedModule_finite_cohomology_pi_FD
universe u
noncomputable section
open Finset Function MvPolynomial
theorem _root_.ProjSpaceCech.GradedModule.finite_cohomology_pi_FD (R : Type u) [CommRing R] (n :
    ℕ) {ι : Type} [Fintype ι] (d₀ : ι → ℤ) (i : ℕ) :
    Module.Finite R (ProjSpaceCech.GradedModule.H (ProjSpaceCech.GradedModule.pi (fun k =>
      ProjSpaceCech.GradedModule.FD R n (d₀ k))) i) :=
  by
  have : ∀ k, Module.Finite R (ProjSpaceCech.GradedModule.H (ProjSpaceCech.GradedModule.FD R n (d₀
    k)) i) :=
    fun k => ProjSpaceCech.GradedModule.finite_cohomology_FD R n (d₀ k) i
  obtain ⟨e⟩ := ProjSpaceCech.GradedModule.nonempty_HEquiv_pi (fun k =>
    ProjSpaceCech.GradedModule.FD R n (d₀ k)) i
  exact Module.Finite.equiv e.symm