English
If a functor is fully faithful and preadditive structure is carried, the Yoneda embedding is additive and full when considering respective forgetful whiskering.
Русский
Если функтор полностью верен и сохраняется предаддитивная структура, образ Yoneda аддитивен и полон после учёта забывающих whiskering.
LaTeX
$$$\text{Yoneda} \text{ is additive and full under forgetful whiskering}$$$
Lean4
theorem finrank_hom_simple_simple_eq_zero_iff (X Y : C) [FiniteDimensional 𝕜 (X ⟶ X)] [FiniteDimensional 𝕜 (X ⟶ Y)]
[Simple X] [Simple Y] : finrank 𝕜 (X ⟶ Y) = 0 ↔ IsEmpty (X ≅ Y) :=
by
rw [← not_nonempty_iff, ← not_congr (finrank_hom_simple_simple_eq_one_iff 𝕜 X Y)]
have := finrank_hom_simple_simple_le_one 𝕜 X Y
cutsat