English
In a sheaf setting, the imageι map composed with toImage recovers the original morphism.
Русский
В условиях шарфа композицию imageι с toImage восстанавливает исходный морфизм.
LaTeX
$$$ toImage f \\;\\;\\; \\text{composed with} \\;\\; imageι f = f $$$
Lean4
theorem eval_app (S₁ S₂ : Sheaf typesGrothendieckTopology (Type u)) (f : S₁ ⟶ S₂) (α : Type u) (s : S₁.1.obj (op α))
(x : α) : eval S₂.1 α (f.val.app (op α) s) x = f.val.app (op PUnit) (eval S₁.1 α s x) :=
(congr_fun (f.val.naturality (↾fun _ : PUnit => x).op) s).symm