English
By Quotient.lift_unique' the quotient functor is an epimorphism: if two functors become equal after precomposition with the quotient, they are equal.
Русский
По Quotient.lift_unique' факторный функтор является эпиморфизмом: если две функторы совпадают после префиксации через факторизацию, то они равны.
LaTeX
$$Quotient.lift_unique'(F1, F2, h) ⇒ F1 = F2$$
Lean4
/-- By `Quotient.lift_unique'` (not `Quotient.lift`) we have that `quotientFunctor V` is an
epimorphism. -/
theorem lift_unique' (V : SSet.Truncated.{u} 2) {D} [Category D] (F₁ F₂ : V.HomotopyCategory ⥤ D)
(h : HomotopyCategory.quotientFunctor V ⋙ F₁ = HomotopyCategory.quotientFunctor V ⋙ F₂) : F₁ = F₂ :=
Quotient.lift_unique' (C := Cat.FreeRefl (OneTruncation₂ V)) (HoRel₂ (V := V)) _ _ h