Multiplicative bases

MultiplicativeBasisDeformations.Statements.IntegralCompanion

Proposition 10.1 for a basic representation-finite algebra #

prop:fixed-integral-companion (integral-deformations.tex), for A basic and representation-finite over an algebraically closed field of characteristic two, C⁽²⁾ the all-one mesh category of Γ_A over 𝔽₂, A⁽²⁾ its projective corner and A⁽⁴⁾ = 𝒪P (tab₂): the statement Prop101Stmt (module and arrow lifts; (1) free Hom modules in every degree with E₄/2E₄ = C⁽²⁾; (2) regular lifts at projective labels; (3) the quadratic mesh presentation of E₄ with unit coefficients reducing to one) holds (fixedIntegralCompanion). The weight refinement is exists_modLiftW₂, exists_arrowLiftW₂ (PrimeWeight.lean). The instance arguments are those of the Auslander–Reiten quiver (S.hasAtMostOneArrow, S.finiteDimensional_meshHom, S.prime_fd).

theorem MultiplicativeBasisDeformations.IndSkeleton.fixedIntegralCompanion {k A : Type w} [Field k] [IsAlgClosed k] [CharP k 2] [Ring A] [Algebra k A] [FiniteDimensional k A] [IsNoetherianRing Aᵐᵒᵖ] (S : IndSkeleton k A) (b : S.ArrowBases) [∀ (x y : S.ARVertex), Subsingleton (x ⟶ y)] [∀ (x y : S.ARVertex), FiniteDimensional k (MeshWalk.meshFam S.arTranslationQuiver (S.arCoefficients b) x ⟶ MeshWalk.meshFam S.arTranslationQuiver (S.arCoefficients b) y)] [∀ (x y : S.ARVertex), FiniteDimensional (ZMod 2) (MeshWalk.meshFam S.arTranslationQuiver (S.oneC (ZMod 2)) x ⟶ MeshWalk.meshFam S.arTranslationQuiver (S.oneC (ZMod 2)) y)] (v₀ : S.ARVertex) (hF : IsRepresentationFinite k (CatAlg.Alg (S.arMeshData b).F0)ᵐᵒᵖ) {ι : Type} [Fintype ι] [DecidableEq ι] (Wd : ι → MeshWalk.MeshWt S.arTranslationQuiver ℤ) :
MeshWalk.Prop101Stmt (S.tab₂ b v₀ hF Wd)

Proposition 10.1 (prop:fixed-integral-companion) for a basic representation-finite algebra in characteristic two.