rewrite [dif_neg (Nat.lt_irrefl _), List.drop_eq_nil_of_le .refl]
case refine_2
α : Type u
as : Array α
p : α → Bool
⊢ Id.run
      (if hlt : size as < size as then
        if p as[size as] = true then true else anyM.loop p as (size as) (_ : size as ≤ size as) (size as + 1)
      else false) =
    List.any (List.drop (size as) as.data) p
case refine_2
α : Type u
as : Array α
p : α → Bool
⊢ Id.run false = List.any [] p