Finite length of a localized kernel and cokernel #
This is the small commutative-algebra adapter needed when the finite module is over a larger coefficient algebra. Finiteness over the base is supplied explicitly; no restriction-of-scalars finiteness of the ambient module is used.
theorem
AlgebraicAnalysis.localized_kernel_and_cokernel_isFiniteLength
{R : Type u_1}
{C : Type u_2}
{E : Type u_3}
[CommRing R]
[CommRing C]
[Algebra R C]
[AddCommGroup E]
[Module C E]
[Module R E]
[IsScalarTower R C E]
[IsNoetherianRing R]
[IsNoetherianRing C]
[Module.Finite C E]
(f : Module.End C E)
[Module.Finite R ↥(↑R f).ker]
[Module.Finite R (E ⧸ (↑R f).range)]
(q : PrimeSpectrum R)
(hqmem : q ∈ Module.support R (E ⧸ (↑R f).range))
(hq : ∀ p ∈ Module.support R (E ⧸ (↑R f).range), p.asIdeal ≤ q.asIdeal → q.asIdeal ≤ p.asIdeal)
:
IsFiniteLength (Localization q.asIdeal.primeCompl) (LocalizedModule q.asIdeal.primeCompl (E ⧸ (↑R f).range)) ∧ IsFiniteLength (Localization q.asIdeal.primeCompl) (LocalizedModule q.asIdeal.primeCompl ↥(↑R f).ker)