(= repeat (mac (i n . body)
  (list 'do
    (list 'let i 0)
    (list 'while (list '< i n)
      (list '= i (list '+ i 1))
      (cons 'do body)))))

; print multiplication table
(repeat i 10
  (repeat j 10
    (print i "x" j "=" (* i j)))
  (print))