AlgebraicCurves.Foundations.Algebra.Proofs.Algebra_exists_lift_basis_of_surjective_of_monogenic_specialFibre.MonogenicLiftSol.main
Source context 8 commands
Surrounding namespaces, section variables, and local commands at this declaration.
section ProofImplementation
namespace AlgebraicCurves.Foundations.Algebra.Proofs
namespace Algebra_exists_lift_basis_of_surjective_of_monogenic_specialFibre
open Polynomial
universe u v w x
noncomputable section
namespace MonogenicLiftSol
open Classical inLean source · statement
theorem main
(R' : Type u) [CommRing R'] [IsLocalRing R'] (R : Type v) [CommRing R] [IsLocalRing R]
(π : R' →+* R) (hπ : Function.Surjective π)
(C : Type w) [CommRing C] [Algebra R C] (ι : Type x) [Finite ι]
(e : Module.Basis ι R C) (i₀ : ι) (he : e i₀ = 1)
(y : C) (hy : ∀ z : C, ∃ q : R[X],
z - aeval y q ∈ (IsLocalRing.maximalIdeal R) • (⊤ : Submodule R C)) :
∃ (C' : Type u) (_ : CommRing C') (_ : Algebra R' C') (e' : Module.Basis ι R' C')
(σ : C' →+* C),
e' i₀ = 1 ∧ (∀ r, σ (algebraMap R' C' r) = algebraMap R C (π r)) ∧ ∀ i, σ (e' i) = e i