fn binarySearchRecursive arr value lower upper =
(
    if lower == upper then
    (
        if arr[lower] == value then
        (
            return lower
        )
        else
        (
            return -1
        )
    )
    mid = (lower + upper) / 2
    if arr[mid] > value then
    (
        return binarySearchRecursive arr value lower (mid-1)
    )
    else if arr[mid] < value then
    (
        return binarySearchRecursive arr value (mid+1) upper
    )
    else
    (
        return mid
    )
)

arr = #(1, 3, 4, 5, 6, 7, 8, 9, 10)
result = binarySearchRecursive arr 6 1 arr.count