The module-side inverse natural isomorphism #
noncomputable def
MagnitudeConjecture.Graded.FiniteGradedModule.supportedModuleRecoveryUnit
{k A : Type u}
[Field k]
[Ring A]
[Algebra k A]
[FiniteDimensional k A]
(R : VectorGrading k A)
(hmul : ∀ {i j : ℤ} {a b : A}, a ∈ R.component i → b ∈ R.component j → a * b ∈ R.component (i + j))
{ι : Type}
[Fintype ι]
(e : ι → A)
(he0 : ∀ (i : ι), e i ∈ R.component 0)
(he : ∀ (i : ι), e i * e i = e i)
(hsum : ∑ i : ι, e i = 1)
(horth : Pairwise fun (i j : ι) => e i * e j = 0)
(m : ℕ)
(hneg : ∀ d < 0, R.component d = ⊥)
(h1 : 1 ∈ R.component 0)
:
CategoryTheory.Functor.id (SupportedCategory m) ≅ (principalSupportedEvaluationFunctor R ⋯ e he0 he m).comp
(supportedIntervalReconstructionFunctor R ⋯ e he0 he hneg h1 hsum horth m)
Evaluation followed by reconstruction recovers the actual supported graded module naturally.