get "libhdr"

let start() be
$(  let a = ? and b = ?
    writes("A? ") ; a := readn()
    writes("B? ") ; b := readn()

    writes(
         a < b -> "A is less than B*N",
         a = b -> "A is equal to B*N",
         a > b -> "A is greater than B*N",
         "Huh?!"
    )
$)