rfl
α : Type u
m : Type v → Type w
inst✝¹ : Monad m
β : Type v
inst✝ : LawfulMonad m
f : α → m β
x : Array α
a : α
⊢ (do
      let b ← f a
      pure (cons b #[])) =
    do
    let b ← f a
    pure (push #[] b)
no goals