get "libhdr"

let reduce(f, v, len, seed) =
    len = 0 -> seed,
    reduce(f, v+1, len-1, f(!v, seed))

let start() be
$(  let add(x, y) = x+y
    let mul(x, y) = x*y

    let nums = table 1,2,3,4,5,6,7

    writef("%N*N", reduce(add, nums, 7, 0))
    writef("%N*N", reduce(mul, nums, 7, 1))
$)