no goals
σ : Type u
F G : Type u → Type u
inst✝¹ : Applicative F
inst✝ : Applicative G
α β γ : Type u
g : α → β
f : β → G γ
x : σ ⊕ α
⊢ Sum.traverse f (g <$> x) = Sum.traverse (f ∘ g) x
cases x <;> simp [Sum.traverse, id_map, functor_norm] <;> rfl