induction as
α : Type u
inst✝ : Category α
as : List α
⊢ joinF.unitorRightOplax as ≫ joinF.unitorRightLax as =
    𝟙 (Prefunctor.obj (Prefunctor.obj mapF.toPrefunctor singletonF ⋙ joinF).toPrefunctor as)
case nil
α : Type u
inst✝ : Category α
⊢ joinF.unitorRightOplax [] ≫ joinF.unitorRightLax [] =
    𝟙 (Prefunctor.obj (Prefunctor.obj mapF.toPrefunctor singletonF ⋙ joinF).toPrefunctor [])

case cons
α : Type u
inst✝ : Category α
head✝ : α
tail✝ : List α
tail_ih✝ :
  joinF.unitorRightOplax tail✝ ≫ joinF.unitorRightLax tail✝ =
    𝟙 (Prefunctor.obj (Prefunctor.obj mapF.toPrefunctor singletonF ⋙ joinF).toPrefunctor tail✝)
⊢ joinF.unitorRightOplax (head✝ :: tail✝) ≫ joinF.unitorRightLax (head✝ :: tail✝) =
    𝟙 (Prefunctor.obj (Prefunctor.obj mapF.toPrefunctor singletonF ⋙ joinF).toPrefunctor (head✝ :: tail✝))