English
The forgetful functor forget CommMonCat reflects isomorphisms: if a morphism becomes an isomorphism after forgetting the CommMonCat structure, then it was an isomorphism.
Русский
Забывающий функтор CommMonCat отражает изоморфизмы.
LaTeX
$$$\text{Forget}_{CommMonCat}$ reflects isomorphisms.$$
Lean4
@[to_additive]
instance forget_reflects_isos : (forget CommMonCat.{u}).ReflectsIsomorphisms where
reflects {X Y} f
_ := by
let i := asIso ((forget CommMonCat).map f)
let e : X ≃* Y := { f.hom, i.toEquiv with }
exact e.toCommMonCatIso.isIso_hom