English
ThinSkeleton is skeletal; objects are determined up to isomorphism by their thin-structure.
Русский
ThinSkeleton является skeletal; объекты определяются по изоморфности через тонкую структуру.
LaTeX
$$theorem skeletal : Skeletal (ThinSkeleton C)$$
Lean4
/-- Use `Quotient.out` to create a functor out of the thin skeleton. -/
@[simps]
noncomputable def fromThinSkeleton : ThinSkeleton C ⥤ C
where
obj := Quotient.out
map {x}
{y} :=
Quotient.recOnSubsingleton₂ x y fun X Y f =>
(Nonempty.some (Quotient.mk_out X)).hom ≫ f.le.some ≫ (Nonempty.some (Quotient.mk_out Y)).inv