openAI-math-dataset / lean /OAI /Algebra /Finitistic /Bar /IntegerStalk.lean
roseking's picture
Add lean source and binary files (part 7)
216fb31 verified
Raw History Blame Contribute Delete
767 Bytes
import OAI.Algebra.Finitistic.Bar.IntegerDerivedMultibar
namespace OAI
noncomputable section
open CategoryTheory
namespace DerivedBar
universe u
variable (D : Type u) [Ring D]
local instance : HasDerivedCategory.{u+1} (ModuleCat.{u} D) :=
HasDerivedCategory.standard (ModuleCat.{u} D)
/-- The original nonnegative stalk maps to the actual integer derived stalk. -/
def integerStalkIso (N : ModuleCat.{u} D) :
(integerQ D).obj ((ChainComplex.single₀ (ModuleCat D)).obj N) ≅
(DerivedCategory.singleFunctor (ModuleCat D) 0).obj N :=
DerivedCategory.Q.mapIso (HomologicalComplex.extendSingleIso
ComplexShape.embeddingDownNat N 0 0 rfl) ≪≫
((DerivedCategory.singleFunctorIsoCompQ (ModuleCat D) 0).app N).symm
end DerivedBar
end
end OAI