rw [this n .refl]
m : Type u → Type v
inst✝ : Monad m
α : Type u
f : Nat → α → m α
init : α
n : Nat
this : ∀ (k : Nat), k ≤ n → foldM.loop f (n + 1) k = foldM.loop (f ∘ succ) n k
⊢ f 0 init >>= foldM.loop f (n + 1) n = do
    let x ← f 0 init
    foldM.loop (f ∘ succ) n n x
no goals