Positive-length form of a nonsplit recovered morphism #
A nonsplit morphism between recovered standard-form vertices has no nonzero degree-zero scalar term, so its mesh-category preimage is an incoming sum.
@[instance_reducible]
def
MagnitudeConjecture.RightModule.FiniteIndecomposableSkeleton.standardFormARIncomingPreimageQuiver
{k A : Type u}
[Field k]
[Ring A]
[Algebra k A]
[FiniteDimensional k A]
[IsNoetherianRing Aᵐᵒᵖ]
(S : FiniteIndecomposableSkeleton k A)
:
Quiver (Fin S.n)
Instances For
@[instance_reducible]
noncomputable def
MagnitudeConjecture.RightModule.FiniteIndecomposableSkeleton.standardFormARIncomingPreimageArrowFintype
{k A : Type u}
[Field k]
[Ring A]
[Algebra k A]
[FiniteDimensional k A]
[IsNoetherianRing Aᵐᵒᵖ]
(S : FiniteIndecomposableSkeleton k A)
(x y : Fin S.n)
:
Fintype (x ⟶ y)
Instances For
theorem
MagnitudeConjecture.RightModule.FiniteIndecomposableSkeleton.exists_standardFormIncomingCoefficient_preimage_eq_incomingSum
{k A : Type u}
[Field k]
[IsAlgClosed k]
[Ring A]
[Algebra k A]
[FiniteDimensional k A]
[IsNoetherianRing Aᵐᵒᵖ]
(S : FiniteIndecomposableSkeleton k A)
(x z : Fin S.n)
(q :
S.standardFormProjectiveVertexModuleIndecomposableSkeleton.obj x ⟶ S.standardFormProjectiveVertexModuleIndecomposableSkeleton.obj z)
(hq : ¬CategoryTheory.IsSplitEpi q)
:
∃ (coeff : S.standardFormRightMeshData.IncomingCoefficient x z),
(S.standardFormRestrictedYonedaFunctor ⋯).preimage q = S.standardFormRightMeshData.incomingSum coeff
A nonsplit recovered morphism has an incoming-sum preimage in the mesh category.