** CL example :PROPERTIES: :DATE: 2011-04-01 :END: #+begin_src lisp (defun range (n &optional m) "Return the numbers in range." (loop for num from (if m n 0) to (if m m (- n 1)) collect num)) (mapcar #'list (mapcar #'1+ (range 10))) #+end_src | 1 | | 2 | | 3 | | 4 | | 5 | | 6 | | 7 | | 8 | | 9 | | 10 |