English
For a Profinite X, the functor DiscreteQuotient X ⥤ FintypeCat has a limit isomorphic to X.
Русский
Для профинитного пространства X отношенный к нему функтор DiscreteQuotient X ⥤ FintypeCat имеет предел, изоморфный X.
LaTeX
$$$\lim(\mathrm{DiscreteQuotient}(X) \xrightarrow{\mathrm{fintypeDiagram}} \mathrm{FintypeCat}) \cong X$$$
Lean4
/-- The functor `DiscreteQuotient X ⥤ Fintype` whose limit is isomorphic to `X`. -/
def fintypeDiagram : DiscreteQuotient X ⥤ FintypeCat
where
obj S := @FintypeCat.of S (Fintype.ofFinite S)
map f := DiscreteQuotient.ofLE f.le
map_comp _ _ := by funext; cat_disch