∀ {X : SSet.Truncated 2} {C : Type u} [inst : CategoryTheory.SmallCategory C]
  (F : CategoryTheory.Functor X.HomotopyCategory C)
  {x y : X.obj (Opposite.op { obj := { len := 0 }, property := _proof_11✝ })} (e : SSet.Truncated.Edge x y),
  (SSet.Truncated.HomotopyCategory.homToNerveMk F).app
      (Opposite.op { obj := { len := 1 }, property := SSet.Truncated.Edge._proof_2 }) e.edge =
    CategoryTheory.ComposableArrows.mk₁ (F.map (SSet.Truncated.HomotopyCategory.homMk e))