English
There is a natural bijection between isomorphisms X ≅ Y in C and isomorphisms F X ≅ F Y in D provided F is fully faithful.
Русский
Существует естественная биекция между изоморфизмами X ≅ Y в C и изоморфизмами F X ≅ F Y в D при условии, что F полностью верен.
LaTeX
$$$\big(X \cong Y\big) \cong \big(F X \cong F Y\big)$, natural in X,Y, induced by $F.mapIso$ and $F$.preimageIso$$
Lean4
/-- The equivalence `(X ≅ Y) ≃ (F.obj X ≅ F.obj Y)` given by `h : F.FullyFaithful`. -/
@[simps]
def isoEquiv {X Y : C} : (X ≅ Y) ≃ (F.obj X ≅ F.obj Y)
where
toFun := F.mapIso
invFun := hF.preimageIso
left_inv := by cat_disch
right_inv := by cat_disch