The unit of a big tensor product of ind-algebras survives #
In the ind-completion the two inputs of the general criterion are available: the tensor of two nonzero points is nonzero, and a point of a filtered colimit vanishes only if it already vanishes at a later stage. So a tensor product of an arbitrary family of algebras with nonvanishing units again has a nonvanishing unit — the step Deligne asserts without proof in 2.11.
theorem
RS.id_indUnit_ne_zero
{C : Type v}
[CategoryTheory.SmallCategory C]
[CategoryTheory.MonoidalCategory C]
[CategoryTheory.Abelian C]
[CategoryTheory.Linear ℂ C]
(hu : HasScalarUnit C)
:
The identity of the unit of the ind-completion is nonzero.
theorem
RS.bigTensorUnit_ne_zero_ind
{C : Type v}
[CategoryTheory.SmallCategory C]
[CategoryTheory.MonoidalCategory C]
[CategoryTheory.Abelian C]
[CategoryTheory.Linear ℂ C]
[CategoryTheory.MonoidalPreadditive C]
[CategoryTheory.RigidCategory C]
[CategoryTheory.BraidedCategory (CategoryTheory.Ind C)]
{ι : Type v}
[LinearOrder ι]
(B : ι → CategoryTheory.Ind C)
[(i : ι) → CategoryTheory.MonObj (B i)]
(hu : HasScalarUnit C)
(hB : ∀ (i : ι), CategoryTheory.MonObj.one ≠ 0)
:
The unit of a big tensor product of ind-algebras survives.