union slot =
    | None
    | Held : (heap {value : (heap {value : heap {value : i32 * string} * heap {value : i32 * string}}) * i32})

union wrap =
    | Absent
    | Box : (heap {value : slot})

nominal box_array = array_base (heap {value : wrap})

inl create (n : i32) : box_array = box_array !!!!ArrayCreate(`(heap {value : wrap}), n)
inl get (values : box_array) (i : i32) : heap {value : wrap} =
    match values with
    | box_array raw => !!!!ArrayIndex(raw, i)
inl set (values : box_array) (i : i32) (value : heap {value : wrap}) : () =
    match values with
    | box_array raw => !!!!ArrayIndexSet(raw, i, value)

let score x : i32 =
    match x with
    | Absent => 1i32
    | Box box =>
        inl opened = !!!!LayoutIndex(box)
        match opened.value with
        | None => 1i32
        | Held inner =>
            inl inner_opened = !!!!LayoutIndex(inner)
            inl ~(inner_held, flag) = inner_opened.value
            inl deep_opened = !!!!LayoutIndex(inner_held)
            inl ~(left, right) = deep_opened.value
            inl left_opened = !!!!LayoutIndex(left)
            inl ~(a, b) = left_opened.value
            inl right_opened = !!!!LayoutIndex(right)
            inl ~(c, d) = right_opened.value
            if a =. 7i32 && !!!!EQ(b, "hi") && c =. 4i32 && !!!!EQ(d, "yo") && flag =. 2i32 then 0i32 else 1i32

inl main () : i32 =
    inl ~n = 7i32
    inl ~word = "hi"
    inl left_pair = n, word
    inl left_heap = !!!!LayoutToHeap({value = left_pair})
    inl ~m = 4i32
    inl ~other = "yo"
    inl right_pair = m, other
    inl right_heap = !!!!LayoutToHeap({value = right_pair})
    inl pair = left_heap, right_heap
    inl inner = !!!!LayoutToHeap({value = pair})
    inl ~mark = 2i32
    inl outer_pair = inner, mark
    inl outer = !!!!LayoutToHeap({value = outer_pair})
    inl ~on = true
    inl held = if on then Held outer else None
    inl box = !!!!LayoutToHeap({value = held})
    inl ~use_box = true
    inl wrapped = if use_box then Box box else Absent
    inl cover = !!!!LayoutToHeap({value = wrapped})
    inl values = create 1i32
    set values 0i32 cover
    inl loaded = get values 0i32
    inl opened = !!!!LayoutIndex(loaded)
    score opened.value