The Main Transfinite Construction #
An ordinal-indexed chain of A-extensions whose union satisfies Heitmann's Proposition 1 (surjectivity onto T/M² and ideal contraction), yielding a Noetherian local domain with prescribed completion (Jensen, 2006, Corollary 2.4).
theorem
jensen_construction_p0_uncountable
{T : Type u}
[CommRing T]
[IsLocalRing T]
[IsNoetherianRing T]
[IsDomain T]
[IsAdicComplete (IsLocalRing.maximalIdeal T) T]
(hdepth :
∃ (a : T) (b : T),
a ∈ IsLocalRing.maximalIdeal T ∧ b ∈ IsLocalRing.maximalIdeal T ∧ RingTheory.Sequence.IsRegular T [a, b])
(hcard : Cardinal.mk T = Cardinal.mk (IsLocalRing.ResidueField T))
(hchar : ∀ (n : ℤ), n ≠ 0 → (algebraMap ℤ T) n ≠ 0)
(hT_aleph0 : Cardinal.aleph0 < Cardinal.mk T)
(hht : ∀ (P : Ideal T), P.IsPrime → P ≠ IsLocalRing.maximalIdeal T → P.height ≤ 1)
:
∃ (A : Type u) (x : CommRing A) (x_1 : IsLocalRing A) (_ : IsDomain A) (_ : UniqueFactorizationMonoid A) (_ :
IsNoetherianRing A), Nonempty (AdicCompletion (IsLocalRing.maximalIdeal A) A ≃+* T) ∧ HasTrivialGenericFormalFiber A