English
There is a canonical morphism liftHom: F.obj j ⟶ X, defined as the descents through the colimit induced by the isWellOrderContinuous structure, using a cocone built from the family s.
Русский
Существует каноническое отображение liftHom: F.obj j ⟶ X, определяемое как факторизация через колимит, индуцированный структурой IsWellOrderContinuous, используя кокон, построенный из семейства s.
LaTeX
$$$$ liftHom_j : F(obj\, j) \to X $$ defined by\ desc\; (F.isColimitOfIsWellOrderContinuous\ j\ hj)\ Cocone.mk\ { app := \lambda i, (s.1 ⟨i⟩).f' ... } $$$$
Lean4
/-- Auxiliary definition for `transfiniteComposition.wellOrderInductionData`. -/
noncomputable def liftHom : F.obj j ⟶ X :=
(F.isColimitOfIsWellOrderContinuous j hj).desc
(Cocone.mk _
{ app := fun i ↦ (s.1 ⟨i⟩).f'
naturality i i'
g := by
have := congr_arg SqStruct.f' (s.2 g.op)
dsimp at this ⊢
rw [this, comp_id] })