[http:/d.hatena.ne.jp/nowokay/20080717#1216294670] via:[http:/d.hatena.ne.jp/yuki_neko_nyan/20080718/1216340919:itle] (defun gen-perm (terms &optional (l nil)) (unless l (setf l (length terms))) (labels ((iter (acc &rest arg) (if (= l (len…