ref: b99d8715ce8ea2f97f25d65b628421c49087e23c
dir: /femtolisp/pisum.lsp/
(defun pisum ()
(dotimes (j 500)
((label sumloop
(lambda (i sum)
(if (> i 10000)
sum
(sumloop (+ i 1) (+ sum (/ (* i i)))))))
1.0 0.0)))