let rec same_length left right =
  match (left, right) with
  | [], [] -> true
  | _ :: left, _ :: right -> same_length left right
  | _ -> false

let rec matches ~element expected actual =
  match (expected, actual) with
  | [], [] -> true
  | expected :: expected_rest, actual :: actual_rest ->
      element expected actual && matches ~element expected_rest actual_rest
  | _ -> false