OAI/Algebra/Finitistic/Ordinary/OrdinaryFreeTensorExactness.lean
3 declarations, 0 contain sorry, 0 declared as axioms
- theorem
OAI.LittleFinitistic.BalancedTensor.Free.evaluation_naturalityline 15 - theorem
OAI.LittleFinitistic.BalancedTensor.Free.finsupp_exactline 32Source documentation
Direct sums preserve exactness, with a preimage supported on the given finite support.
theorem finsupp_exact (f : N →ₗ[A] N') (g : N' →ₗ[A] N'') (h : Function.Exact f g) : Function.Exact (Finsupp.mapRange.linearMap (f.restrictScalars k) : (I →₀ N) →ₗ[k] (I →₀ N')) (Finsupp.mapRange.linearMap (g.restrictScalars k)) := by … - theorem
OAI.LittleFinitistic.BalancedTensor.Free.tensor_exactline 57Source documentation
Tensor by an arbitrary free right module preserves every exact module sequence.
theorem tensor_exact (f : N →ₗ[A] N') (g : N' →ₗ[A] N'') (h : Function.Exact f g) : Function.Exact (mapRightTo (k := k) (M := I →₀ Aᵐᵒᵖ) f) …