Nonzero representable generators of finite functors #
Every nonzero finite-dimensional functor receives a nonzero morphism from one finite-dimensional representable. This is the componentwise form of the finite-representable generation theorem.
theorem
MagnitudeConjecture.CoveringHom.finiteDimensionalModule_exists_nonzero_representableMap
{k : Type uK}
[Field k]
{C : Type u}
[CategoryTheory.Category.{v, u} C]
[CategoryTheory.Preadditive C]
[CategoryTheory.Linear k C]
(hP : ∀ (X : C), IsFiniteDimensionalModule k (linearCoyonedaLinearModule X))
{M : FiniteDimensionalModuleCategory k}
(hM : ¬CategoryTheory.Limits.IsZero M)
:
∃ (X : C) (f : finiteDimensionalLinearCoyoneda X ⋯ ⟶ M), f ≠ 0
A nonzero finite-dimensional functor receives a nonzero map from a finite-dimensional representable.