get "libhdr"

let fib(n) = n<=1 -> n, valof
$(  let a=0 and b=1
    for i=2 to n
    $(  let c=a
        a := b
        b := a+c
    $)
    resultis b
$)

let start() be
    for i=0 to 10 do
        writef("F_%N*T= %N*N", i, fib(i))