ref: e4e8d4dfdbad64af64e117554c6d41f0814c3a33
dir: /femtolisp/pisum.lsp/
(define (pisum)
(dotimes (j 500)
((label sumloop
(lambda (i sum)
(if (> i 10000)
sum
(sumloop (+ i 1) (+ sum (/ (* i i)))))))
1.0 0.0)))