The trichotomy, unconditionally #
Both steps of the dévissage are constructions, the trichotomy and the exit are theorems, and a killing diagram bounds the counts, so the recursion runs to completion from the initial state: an object killed by some Schur functor is locally a mixed sum of the unit and the odd line.
theorem
RS.prop29
{C : Type v}
[CategoryTheory.SmallCategory C]
[CategoryTheory.MonoidalCategory C]
[CategoryTheory.SymmetricCategory C]
[CategoryTheory.Abelian C]
[CategoryTheory.RigidCategory C]
[CategoryTheory.MonoidalPreadditive C]
[CategoryTheory.Linear ℂ (CategoryTheory.Ind C)]
[CategoryTheory.MonoidalLinear ℂ (CategoryTheory.Ind C)]
(P : SchurPackage)
(P₀ : SchurPackage)
(L : OddLine (CategoryTheory.Ind C))
(X Y : CategoryTheory.Ind C)
[CategoryTheory.ExactPairing X Y]
(h1 : ¬CategoryTheory.Limits.IsZero (CategoryTheory.MonoidalCategoryStruct.tensorUnit (CategoryTheory.Ind C)))
:
Prop29Statement P L X
The trichotomy of Deligne 2.9, discharged: an object with an exact pairing that is killed by some Schur functor is locally a mixed sum of the unit and the odd line.