pub fn append(zlsts: ZList(ZList(a))) -> ZList(a)

pub fn cartesian(zl_1: ZList(a), zl_2: ZList(a)) -> ZList(a)

pub fn count(zl: ZList(a)) -> Int

pub fn drop(n: Int, zl: ZList(a)) -> ZList(a)

pub fn dropwhile(pred: fn(a) -> Bool, zl: ZList(a)) -> ZList(a)

pub fn expand(zl: ZList(a)) -> List(a)

pub fn filter(pred: fn(a) -> Bool, zl: ZList(a)) -> ZList(a)

pub fn foldl(f: fn(a, b) -> b, accum: b, zl: ZList(a)) -> b

pub fn foreach(f: fn(a) -> b, zl: ZList(a)) -> Nil

pub fn generate(zl: ZList(a), f: fn(a) -> ZList(b)) -> ZList(b)

pub fn map(f: fn(a) -> b, zl: ZList(a)) -> ZList(b)

pub fn merge(zl_1: ZList(a), zl_2: ZList(a)) -> ZList(a)

pub fn new_1(ls: List(a), f: fn() -> List(a)) -> ZList(a)

pub fn new_2(ls: ZList(a), f: fn() -> ZList(a)) -> ZList(a)

pub fn print(zl: ZList(a)) -> Nil

pub fn recurrent_2(elem: a, f: fn(a) -> a) -> ZList(a)

pub fn recurrent_3(
  elem: a,
  elem_1: b,
  f: fn(a, b) -> tuple(a, b),
) -> ZList(a)

pub fn scroll(n: Int, zl: ZList(a)) -> tuple(List(a), ZList(a))

pub fn seq(from: Int, to: Int, incr: Int) -> ZList(Int)

pub fn splitwith(
  pred: fn(a) -> Bool,
  zl: ZList(a),
) -> tuple(List(a), ZList(a))

pub fn take(n: Int, zl: ZList(a)) -> ZList(a)

pub fn takewhile(pred: fn(a) -> Bool, zl: ZList(a)) -> ZList(a)

pub fn unique_1(zl: ZList(a)) -> ZList(a)

pub fn unique_2(pred: fn(a, a) -> Bool, zl: ZList(a)) -> ZList(a)

pub fn zip(zl_1: ZList(a), zl_2: ZList(b)) -> ZList(tuple(a, b))

pub fn ziph(zl_1: ZList(a), zl_2: ZList(b)) -> ZList(tuple(a, b))