Lean4
/-- The unit of the adjunction `lightCondSetToTopCat ⊣ topCatToLightCondSet` -/
@[simps val_app val_app_apply]
noncomputable def topCatAdjunctionUnit (X : LightCondSet.{u}) : X ⟶ X.toTopCat.toLightCondSet where
val :=
{ app := fun S x ↦
{ toFun := fun s ↦ X.val.map ((of PUnit.{u + 1}).const s).op x
continuous_toFun :=
by
suffices
∀ (i : (T : LightProfinite.{u}) × X.val.obj ⟨T⟩), Continuous (fun (a : i.fst) ↦ X.coinducingCoprod ⟨i, a⟩)
from this ⟨_, _⟩
rw [← continuous_sigma_iff]
apply continuous_coinduced_rng }
naturality := fun _ _ _ ↦ by
ext
simp only [TopCat.toSheafCompHausLike_val_obj, Opposite.op_unop, types_comp_apply,
TopCat.toSheafCompHausLike_val_map, ← FunctorToTypes.map_comp_apply]
rfl }