rw [Nat.sub_sub_self h]
α : Type u
as : Array α
n : Nat
h : n ≤ size as
this : ∀ (i k : Nat) (hk : k ≤ size as) (hi : i < size as - k), (shrink.loop k as)[i] = as[i]
i : Nat
hi : i < size (shrink.loop (size as - n) as)
⊢ i < size as - (size as - n)
α : Type u
as : Array α
n : Nat
h : n ≤ size as
this : ∀ (i k : Nat) (hk : k ≤ size as) (hi : i < size as - k), (shrink.loop k as)[i] = as[i]
i : Nat
hi : i < size (shrink.loop (size as - n) as)
⊢ i < n